drivers/char/ipmi/ipmi_msghandler.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * ipmi_msghandler.c
   4  *
   5  * Incoming and outgoing message routing for an IPMI interface.
   6  *
   7  * Author: MontaVista Software, Inc.
   8  *         Corey Minyard <minyard@mvista.com>
   9  *         source@mvista.com
  10  *
  11  * Copyright 2002 MontaVista Software Inc.
  12  */
  13
  14 #define pr_fmt(fmt) "IPMI message handler: " fmt
  15 #define dev_fmt(fmt) pr_fmt(fmt)
  16
  17 #include <linux/module.h>
  18 #include <linux/errno.h>
  19 #include <linux/poll.h>
  20 #include <linux/sched.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/mutex.h>
  24 #include <linux/slab.h>
  25 #include <linux/ipmi.h>
  26 #include <linux/ipmi_smi.h>
  27 #include <linux/notifier.h>
  28 #include <linux/init.h>
  29 #include <linux/proc_fs.h>
  30 #include <linux/rcupdate.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/moduleparam.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/uuid.h>
  35 #include <linux/nospec.h>
  36 #include <linux/vmalloc.h>
  37 #include <linux/delay.h>
  38
  39 #define IPMI_DRIVER_VERSION "39.2"
  40
  41 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);
  42 static int ipmi_init_msghandler(void);
  43 static void smi_recv_tasklet(struct tasklet_struct *t);
  44 static void handle_new_recv_msgs(struct ipmi_smi *intf);
  45 static void need_waiter(struct ipmi_smi *intf);
  46 static int handle_one_recv_msg(struct ipmi_smi *intf,
  47                                struct ipmi_smi_msg *msg);
  48
  49 static bool initialized;
  50 static bool drvregistered;
  51
  52 enum ipmi_panic_event_op {
  53         IPMI_SEND_PANIC_EVENT_NONE,
  54         IPMI_SEND_PANIC_EVENT,
  55         IPMI_SEND_PANIC_EVENT_STRING
  56 };
  57 #ifdef CONFIG_IPMI_PANIC_STRING
  58 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_STRING
  59 #elif defined(CONFIG_IPMI_PANIC_EVENT)
  60 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT
  61 #else
  62 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_NONE
  63 #endif
  64
  65 static enum ipmi_panic_event_op ipmi_send_panic_event = IPMI_PANIC_DEFAULT;
  66
  67 static int panic_op_write_handler(const char *val,
  68                                   const struct kernel_param *kp)
  69 {
  70         char valcp[16];
  71         char *s;
  72
  73         strncpy(valcp, val, 15);
  74         valcp[15] = '\0';
  75
  76         s = strstrip(valcp);
  77
  78         if (strcmp(s, "none") == 0)
  79                 ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT_NONE;
  80         else if (strcmp(s, "event") == 0)
  81                 ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT;
  82         else if (strcmp(s, "string") == 0)
  83                 ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT_STRING;
  84         else
  85                 return -EINVAL;
  86
  87         return 0;
  88 }
  89
  90 static int panic_op_read_handler(char *buffer, const struct kernel_param *kp)
  91 {
  92         switch (ipmi_send_panic_event) {
  93         case IPMI_SEND_PANIC_EVENT_NONE:
  94                 strcpy(buffer, "none\n");
  95                 break;
  96
  97         case IPMI_SEND_PANIC_EVENT:
  98                 strcpy(buffer, "event\n");
  99                 break;
 100
 101         case IPMI_SEND_PANIC_EVENT_STRING:
 102                 strcpy(buffer, "string\n");
 103                 break;
 104
 105         default:
 106                 strcpy(buffer, "???\n");
 107                 break;
 108         }
 109
 110         return strlen(buffer);
 111 }
 112
 113 static const struct kernel_param_ops panic_op_ops = {
 114         .set = panic_op_write_handler,
 115         .get = panic_op_read_handler
 116 };
 117 module_param_cb(panic_op, &panic_op_ops, NULL, 0600);
 118 MODULE_PARM_DESC(panic_op, "Sets if the IPMI driver will attempt to store panic information in the event log in the event of a panic.  Set to 'none' for no, 'event' for a single event, or 'string' for a generic event and the panic string in IPMI OEM events.");
 119
 120
 121 #define MAX_EVENTS_IN_QUEUE     25
 122
 123 /* Remain in auto-maintenance mode for this amount of time (in ms). */
 124 static unsigned long maintenance_mode_timeout_ms = 30000;
 125 module_param(maintenance_mode_timeout_ms, ulong, 0644);
 126 MODULE_PARM_DESC(maintenance_mode_timeout_ms,
 127                  "The time (milliseconds) after the last maintenance message that the connection stays in maintenance mode.");
 128
 129 /*
 130  * Don't let a message sit in a queue forever, always time it with at lest
 131  * the max message timer.  This is in milliseconds.
 132  */
 133 #define MAX_MSG_TIMEOUT         60000
 134
 135 /*
 136  * Timeout times below are in milliseconds, and are done off a 1
 137  * second timer.  So setting the value to 1000 would mean anything
 138  * between 0 and 1000ms.  So really the only reasonable minimum
 139  * setting it 2000ms, which is between 1 and 2 seconds.
 140  */
 141
 142 /* The default timeout for message retries. */
 143 static unsigned long default_retry_ms = 2000;
 144 module_param(default_retry_ms, ulong, 0644);
 145 MODULE_PARM_DESC(default_retry_ms,
 146                  "The time (milliseconds) between retry sends");
 147
 148 /* The default timeout for maintenance mode message retries. */
 149 static unsigned long default_maintenance_retry_ms = 3000;
 150 module_param(default_maintenance_retry_ms, ulong, 0644);
 151 MODULE_PARM_DESC(default_maintenance_retry_ms,
 152                  "The time (milliseconds) between retry sends in maintenance mode");
 153
 154 /* The default maximum number of retries */
 155 static unsigned int default_max_retries = 4;
 156 module_param(default_max_retries, uint, 0644);
 157 MODULE_PARM_DESC(default_max_retries,
 158                  "The time (milliseconds) between retry sends in maintenance mode");
 159
 160 /* Call every ~1000 ms. */
 161 #define IPMI_TIMEOUT_TIME       1000
 162
 163 /* How many jiffies does it take to get to the timeout time. */
 164 #define IPMI_TIMEOUT_JIFFIES    ((IPMI_TIMEOUT_TIME * HZ) / 1000)
 165
 166 /*
 167  * Request events from the queue every second (this is the number of
 168  * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
 169  * future, IPMI will add a way to know immediately if an event is in
 170  * the queue and this silliness can go away.
 171  */
 172 #define IPMI_REQUEST_EV_TIME    (1000 / (IPMI_TIMEOUT_TIME))
 173
 174 /* How long should we cache dynamic device IDs? */
 175 #define IPMI_DYN_DEV_ID_EXPIRY  (10 * HZ)
 176
 177 /*
 178  * The main "user" data structure.
 179  */
 180 struct ipmi_user {
 181         struct list_head link;
 182
 183         /*
 184          * Set to NULL when the user is destroyed, a pointer to myself
 185          * so srcu_dereference can be used on it.
 186          */
 187         struct ipmi_user *self;
 188         struct srcu_struct release_barrier;
 189
 190         struct kref refcount;
 191
 192         /* The upper layer that handles receive messages. */
 193         const struct ipmi_user_hndl *handler;
 194         void             *handler_data;
 195
 196         /* The interface this user is bound to. */
 197         struct ipmi_smi *intf;
 198
 199         /* Does this interface receive IPMI events? */
 200         bool gets_events;
 201
 202         /* Free must run in process context for RCU cleanup. */
 203         struct work_struct remove_work;
 204 };
 205
 206 static struct workqueue_struct *remove_work_wq;
 207
 208 static struct ipmi_user *acquire_ipmi_user(struct ipmi_user *user, int *index)
 209         __acquires(user->release_barrier)
 210 {
 211         struct ipmi_user *ruser;
 212
 213         *index = srcu_read_lock(&user->release_barrier);
 214         ruser = srcu_dereference(user->self, &user->release_barrier);
 215         if (!ruser)
 216                 srcu_read_unlock(&user->release_barrier, *index);
 217         return ruser;
 218 }
 219
 220 static void release_ipmi_user(struct ipmi_user *user, int index)
 221 {
 222         srcu_read_unlock(&user->release_barrier, index);
 223 }
 224
 225 struct cmd_rcvr {
 226         struct list_head link;
 227
 228         struct ipmi_user *user;
 229         unsigned char netfn;
 230         unsigned char cmd;
 231         unsigned int  chans;
 232
 233         /*
 234          * This is used to form a linked lised during mass deletion.
 235          * Since this is in an RCU list, we cannot use the link above
 236          * or change any data until the RCU period completes.  So we
 237          * use this next variable during mass deletion so we can have
 238          * a list and don't have to wait and restart the search on
 239          * every individual deletion of a command.
 240          */
 241         struct cmd_rcvr *next;
 242 };
 243
 244 struct seq_table {
 245         unsigned int         inuse : 1;
 246         unsigned int         broadcast : 1;
 247
 248         unsigned long        timeout;
 249         unsigned long        orig_timeout;
 250         unsigned int         retries_left;
 251
 252         /*
 253          * To verify on an incoming send message response that this is
 254          * the message that the response is for, we keep a sequence id
 255          * and increment it every time we send a message.
 256          */
 257         long                 seqid;
 258
 259         /*
 260          * This is held so we can properly respond to the message on a
 261          * timeout, and it is used to hold the temporary data for
 262          * retransmission, too.
 263          */
 264         struct ipmi_recv_msg *recv_msg;
 265 };
 266
 267 /*
 268  * Store the information in a msgid (long) to allow us to find a
 269  * sequence table entry from the msgid.
 270  */
 271 #define STORE_SEQ_IN_MSGID(seq, seqid) \
 272         ((((seq) & 0x3f) << 26) | ((seqid) & 0x3ffffff))
 273
 274 #define GET_SEQ_FROM_MSGID(msgid, seq, seqid) \
 275         do {                                                            \
 276                 seq = (((msgid) >> 26) & 0x3f);                         \
 277                 seqid = ((msgid) & 0x3ffffff);                          \
 278         } while (0)
 279
 280 #define NEXT_SEQID(seqid) (((seqid) + 1) & 0x3ffffff)
 281
 282 #define IPMI_MAX_CHANNELS       16
 283 struct ipmi_channel {
 284         unsigned char medium;
 285         unsigned char protocol;
 286 };
 287
 288 struct ipmi_channel_set {
 289         struct ipmi_channel c[IPMI_MAX_CHANNELS];
 290 };
 291
 292 struct ipmi_my_addrinfo {
 293         /*
 294          * My slave address.  This is initialized to IPMI_BMC_SLAVE_ADDR,
 295          * but may be changed by the user.
 296          */
 297         unsigned char address;
 298
 299         /*
 300          * My LUN.  This should generally stay the SMS LUN, but just in
 301          * case...
 302          */
 303         unsigned char lun;
 304 };
 305
 306 /*
 307  * Note that the product id, manufacturer id, guid, and device id are
 308  * immutable in this structure, so dyn_mutex is not required for
 309  * accessing those.  If those change on a BMC, a new BMC is allocated.
 310  */
 311 struct bmc_device {
 312         struct platform_device pdev;
 313         struct list_head       intfs; /* Interfaces on this BMC. */
 314         struct ipmi_device_id  id;
 315         struct ipmi_device_id  fetch_id;
 316         int                    dyn_id_set;
 317         unsigned long          dyn_id_expiry;
 318         struct mutex           dyn_mutex; /* Protects id, intfs, & dyn* */
 319         guid_t                 guid;
 320         guid_t                 fetch_guid;
 321         int                    dyn_guid_set;
 322         struct kref            usecount;
 323         struct work_struct     remove_work;
 324         unsigned char          cc; /* completion code */
 325 };
 326 #define to_bmc_device(x) container_of((x), struct bmc_device, pdev.dev)
 327
 328 static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
 329                              struct ipmi_device_id *id,
 330                              bool *guid_set, guid_t *guid);
 331
 332 /*
 333  * Various statistics for IPMI, these index stats[] in the ipmi_smi
 334  * structure.
 335  */
 336 enum ipmi_stat_indexes {
 337         /* Commands we got from the user that were invalid. */
 338         IPMI_STAT_sent_invalid_commands = 0,
 339
 340         /* Commands we sent to the MC. */
 341         IPMI_STAT_sent_local_commands,
 342
 343         /* Responses from the MC that were delivered to a user. */
 344         IPMI_STAT_handled_local_responses,
 345
 346         /* Responses from the MC that were not delivered to a user. */
 347         IPMI_STAT_unhandled_local_responses,
 348
 349         /* Commands we sent out to the IPMB bus. */
 350         IPMI_STAT_sent_ipmb_commands,
 351
 352         /* Commands sent on the IPMB that had errors on the SEND CMD */
 353         IPMI_STAT_sent_ipmb_command_errs,
 354
 355         /* Each retransmit increments this count. */
 356         IPMI_STAT_retransmitted_ipmb_commands,
 357
 358         /*
 359          * When a message times out (runs out of retransmits) this is
 360          * incremented.
 361          */
 362         IPMI_STAT_timed_out_ipmb_commands,
 363
 364         /*
 365          * This is like above, but for broadcasts.  Broadcasts are
 366          * *not* included in the above count (they are expected to
 367          * time out).
 368          */
 369         IPMI_STAT_timed_out_ipmb_broadcasts,
 370
 371         /* Responses I have sent to the IPMB bus. */
 372         IPMI_STAT_sent_ipmb_responses,
 373
 374         /* The response was delivered to the user. */
 375         IPMI_STAT_handled_ipmb_responses,
 376
 377         /* The response had invalid data in it. */
 378         IPMI_STAT_invalid_ipmb_responses,
 379
 380         /* The response didn't have anyone waiting for it. */
 381         IPMI_STAT_unhandled_ipmb_responses,
 382
 383         /* Commands we sent out to the IPMB bus. */
 384         IPMI_STAT_sent_lan_commands,
 385
 386         /* Commands sent on the IPMB that had errors on the SEND CMD */
 387         IPMI_STAT_sent_lan_command_errs,
 388
 389         /* Each retransmit increments this count. */
 390         IPMI_STAT_retransmitted_lan_commands,
 391
 392         /*
 393          * When a message times out (runs out of retransmits) this is
 394          * incremented.
 395          */
 396         IPMI_STAT_timed_out_lan_commands,
 397
 398         /* Responses I have sent to the IPMB bus. */
 399         IPMI_STAT_sent_lan_responses,
 400
 401         /* The response was delivered to the user. */
 402         IPMI_STAT_handled_lan_responses,
 403
 404         /* The response had invalid data in it. */
 405         IPMI_STAT_invalid_lan_responses,
 406
 407         /* The response didn't have anyone waiting for it. */
 408         IPMI_STAT_unhandled_lan_responses,
 409
 410         /* The command was delivered to the user. */
 411         IPMI_STAT_handled_commands,
 412
 413         /* The command had invalid data in it. */
 414         IPMI_STAT_invalid_commands,
 415
 416         /* The command didn't have anyone waiting for it. */
 417         IPMI_STAT_unhandled_commands,
 418
 419         /* Invalid data in an event. */
 420         IPMI_STAT_invalid_events,
 421
 422         /* Events that were received with the proper format. */
 423         IPMI_STAT_events,
 424
 425         /* Retransmissions on IPMB that failed. */
 426         IPMI_STAT_dropped_rexmit_ipmb_commands,
 427
 428         /* Retransmissions on LAN that failed. */
 429         IPMI_STAT_dropped_rexmit_lan_commands,
 430
 431         /* This *must* remain last, add new values above this. */
 432         IPMI_NUM_STATS
 433 };
 434
 435
 436 #define IPMI_IPMB_NUM_SEQ       64
 437 struct ipmi_smi {
 438         struct module *owner;
 439
 440         /* What interface number are we? */
 441         int intf_num;
 442
 443         struct kref refcount;
 444
 445         /* Set when the interface is being unregistered. */
 446         bool in_shutdown;
 447
 448         /* Used for a list of interfaces. */
 449         struct list_head link;
 450
 451         /*
 452          * The list of upper layers that are using me.  seq_lock write
 453          * protects this.  Read protection is with srcu.
 454          */
 455         struct list_head users;
 456         struct srcu_struct users_srcu;
 457
 458         /* Used for wake ups at startup. */
 459         wait_queue_head_t waitq;
 460
 461         /*
 462          * Prevents the interface from being unregistered when the
 463          * interface is used by being looked up through the BMC
 464          * structure.
 465          */
 466         struct mutex bmc_reg_mutex;
 467
 468         struct bmc_device tmp_bmc;
 469         struct bmc_device *bmc;
 470         bool bmc_registered;
 471         struct list_head bmc_link;
 472         char *my_dev_name;
 473         bool in_bmc_register;  /* Handle recursive situations.  Yuck. */
 474         struct work_struct bmc_reg_work;
 475
 476         const struct ipmi_smi_handlers *handlers;
 477         void                     *send_info;
 478
 479         /* Driver-model device for the system interface. */
 480         struct device          *si_dev;
 481
 482         /*
 483          * A table of sequence numbers for this interface.  We use the
 484          * sequence numbers for IPMB messages that go out of the
 485          * interface to match them up with their responses.  A routine
 486          * is called periodically to time the items in this list.
 487          */
 488         spinlock_t       seq_lock;
 489         struct seq_table seq_table[IPMI_IPMB_NUM_SEQ];
 490         int curr_seq;
 491
 492         /*
 493          * Messages queued for delivery.  If delivery fails (out of memory
 494          * for instance), They will stay in here to be processed later in a
 495          * periodic timer interrupt.  The tasklet is for handling received
 496          * messages directly from the handler.
 497          */
 498         spinlock_t       waiting_rcv_msgs_lock;
 499         struct list_head waiting_rcv_msgs;
 500         atomic_t         watchdog_pretimeouts_to_deliver;
 501         struct tasklet_struct recv_tasklet;
 502
 503         spinlock_t             xmit_msgs_lock;
 504         struct list_head       xmit_msgs;
 505         struct ipmi_smi_msg    *curr_msg;
 506         struct list_head       hp_xmit_msgs;
 507
 508         /*
 509          * The list of command receivers that are registered for commands
 510          * on this interface.
 511          */
 512         struct mutex     cmd_rcvrs_mutex;
 513         struct list_head cmd_rcvrs;
 514
 515         /*
 516          * Events that were queues because no one was there to receive
 517          * them.
 518          */
 519         spinlock_t       events_lock; /* For dealing with event stuff. */
 520         struct list_head waiting_events;
 521         unsigned int     waiting_events_count; /* How many events in queue? */
 522         char             delivering_events;
 523         char             event_msg_printed;
 524
 525         /* How many users are waiting for events? */
 526         atomic_t         event_waiters;
 527         unsigned int     ticks_to_req_ev;
 528
 529         spinlock_t       watch_lock; /* For dealing with watch stuff below. */
 530
 531         /* How many users are waiting for commands? */
 532         unsigned int     command_waiters;
 533
 534         /* How many users are waiting for watchdogs? */
 535         unsigned int     watchdog_waiters;
 536
 537         /* How many users are waiting for message responses? */
 538         unsigned int     response_waiters;
 539
 540         /*
 541          * Tells what the lower layer has last been asked to watch for,
 542          * messages and/or watchdogs.  Protected by watch_lock.
 543          */
 544         unsigned int     last_watch_mask;
 545
 546         /*
 547          * The event receiver for my BMC, only really used at panic
 548          * shutdown as a place to store this.
 549          */
 550         unsigned char event_receiver;
 551         unsigned char event_receiver_lun;
 552         unsigned char local_sel_device;
 553         unsigned char local_event_generator;
 554
 555         /* For handling of maintenance mode. */
 556         int maintenance_mode;
 557         bool maintenance_mode_enable;
 558         int auto_maintenance_timeout;
 559         spinlock_t maintenance_mode_lock; /* Used in a timer... */
 560
 561         /*
 562          * If we are doing maintenance on something on IPMB, extend
 563          * the timeout time to avoid timeouts writing firmware and
 564          * such.
 565          */
 566         int ipmb_maintenance_mode_timeout;
 567
 568         /*
 569          * A cheap hack, if this is non-null and a message to an
 570          * interface comes in with a NULL user, call this routine with
 571          * it.  Note that the message will still be freed by the
 572          * caller.  This only works on the system interface.
 573          *
 574          * Protected by bmc_reg_mutex.
 575          */
 576         void (*null_user_handler)(struct ipmi_smi *intf,
 577                                   struct ipmi_recv_msg *msg);
 578
 579         /*
 580          * When we are scanning the channels for an SMI, this will
 581          * tell which channel we are scanning.
 582          */
 583         int curr_channel;
 584
 585         /* Channel information */
 586         struct ipmi_channel_set *channel_list;
 587         unsigned int curr_working_cset; /* First index into the following. */
 588         struct ipmi_channel_set wchannels[2];
 589         struct ipmi_my_addrinfo addrinfo[IPMI_MAX_CHANNELS];
 590         bool channels_ready;
 591
 592         atomic_t stats[IPMI_NUM_STATS];
 593
 594         /*
 595          * run_to_completion duplicate of smb_info, smi_info
 596          * and ipmi_serial_info structures. Used to decrease numbers of
 597          * parameters passed by "low" level IPMI code.
 598          */
 599         int run_to_completion;
 600 };
 601 #define to_si_intf_from_dev(device) container_of(device, struct ipmi_smi, dev)
 602
 603 static void __get_guid(struct ipmi_smi *intf);
 604 static void __ipmi_bmc_unregister(struct ipmi_smi *intf);
 605 static int __ipmi_bmc_register(struct ipmi_smi *intf,
 606                                struct ipmi_device_id *id,
 607                                bool guid_set, guid_t *guid, int intf_num);
 608 static int __scan_channels(struct ipmi_smi *intf, struct ipmi_device_id *id);
 609
 610
 611 /**
 612  * The driver model view of the IPMI messaging driver.
 613  */
 614 static struct platform_driver ipmidriver = {
 615         .driver = {
 616                 .name = "ipmi",
 617                 .bus = &platform_bus_type
 618         }
 619 };
 620 /*
 621  * This mutex keeps us from adding the same BMC twice.
 622  */
 623 static DEFINE_MUTEX(ipmidriver_mutex);
 624
 625 static LIST_HEAD(ipmi_interfaces);
 626 static DEFINE_MUTEX(ipmi_interfaces_mutex);
 627 #define ipmi_interfaces_mutex_held() \
 628         lockdep_is_held(&ipmi_interfaces_mutex)
 629 static struct srcu_struct ipmi_interfaces_srcu;
 630
 631 /*
 632  * List of watchers that want to know when smi's are added and deleted.
 633  */
 634 static LIST_HEAD(smi_watchers);
 635 static DEFINE_MUTEX(smi_watchers_mutex);
 636
 637 #define ipmi_inc_stat(intf, stat) \
 638         atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat])
 639 #define ipmi_get_stat(intf, stat) \
 640         ((unsigned int) atomic_read(&(intf)->stats[IPMI_STAT_ ## stat]))
 641
 642 static const char * const addr_src_to_str[] = {
 643         "invalid", "hotmod", "hardcoded", "SPMI", "ACPI", "SMBIOS", "PCI",
 644         "device-tree", "platform"
 645 };
 646
 647 const char *ipmi_addr_src_to_str(enum ipmi_addr_src src)
 648 {
 649         if (src >= SI_LAST)
 650                 src = 0; /* Invalid */
 651         return addr_src_to_str[src];
 652 }
 653 EXPORT_SYMBOL(ipmi_addr_src_to_str);
 654
 655 static int is_lan_addr(struct ipmi_addr *addr)
 656 {
 657         return addr->addr_type == IPMI_LAN_ADDR_TYPE;
 658 }
 659
 660 static int is_ipmb_addr(struct ipmi_addr *addr)
 661 {
 662         return addr->addr_type == IPMI_IPMB_ADDR_TYPE;
 663 }
 664
 665 static int is_ipmb_bcast_addr(struct ipmi_addr *addr)
 666 {
 667         return addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE;
 668 }
 669
 670 static void free_recv_msg_list(struct list_head *q)
 671 {
 672         struct ipmi_recv_msg *msg, *msg2;
 673
 674         list_for_each_entry_safe(msg, msg2, q, link) {
 675                 list_del(&msg->link);
 676                 ipmi_free_recv_msg(msg);
 677         }
 678 }
 679
 680 static void free_smi_msg_list(struct list_head *q)
 681 {
 682         struct ipmi_smi_msg *msg, *msg2;
 683
 684         list_for_each_entry_safe(msg, msg2, q, link) {
 685                 list_del(&msg->link);
 686                 ipmi_free_smi_msg(msg);
 687         }
 688 }
 689
 690 static void clean_up_interface_data(struct ipmi_smi *intf)
 691 {
 692         int              i;
 693         struct cmd_rcvr  *rcvr, *rcvr2;
 694         struct list_head list;
 695
 696         tasklet_kill(&intf->recv_tasklet);
 697
 698         free_smi_msg_list(&intf->waiting_rcv_msgs);
 699         free_recv_msg_list(&intf->waiting_events);
 700
 701         /*
 702          * Wholesale remove all the entries from the list in the
 703          * interface and wait for RCU to know that none are in use.
 704          */
 705         mutex_lock(&intf->cmd_rcvrs_mutex);
 706         INIT_LIST_HEAD(&list);
 707         list_splice_init_rcu(&intf->cmd_rcvrs, &list, synchronize_rcu);
 708         mutex_unlock(&intf->cmd_rcvrs_mutex);
 709
 710         list_for_each_entry_safe(rcvr, rcvr2, &list, link)
 711                 kfree(rcvr);
 712
 713         for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
 714                 if ((intf->seq_table[i].inuse)
 715                                         && (intf->seq_table[i].recv_msg))
 716                         ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
 717         }
 718 }
 719
 720 static void intf_free(struct kref *ref)
 721 {
 722         struct ipmi_smi *intf = container_of(ref, struct ipmi_smi, refcount);
 723
 724         clean_up_interface_data(intf);
 725         kfree(intf);
 726 }
 727
 728 struct watcher_entry {
 729         int              intf_num;
 730         struct ipmi_smi  *intf;
 731         struct list_head link;
 732 };
 733
 734 int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher)
 735 {
 736         struct ipmi_smi *intf;
 737         int index, rv;
 738
 739         /*
 740          * Make sure the driver is actually initialized, this handles
 741          * problems with initialization order.
 742          */
 743         rv = ipmi_init_msghandler();
 744         if (rv)
 745                 return rv;
 746
 747         mutex_lock(&smi_watchers_mutex);
 748
 749         list_add(&watcher->link, &smi_watchers);
 750
 751         index = srcu_read_lock(&ipmi_interfaces_srcu);
 752         list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
 753                 int intf_num = READ_ONCE(intf->intf_num);
 754
 755                 if (intf_num == -1)
 756                         continue;
 757                 watcher->new_smi(intf_num, intf->si_dev);
 758         }
 759         srcu_read_unlock(&ipmi_interfaces_srcu, index);
 760
 761         mutex_unlock(&smi_watchers_mutex);
 762
 763         return 0;
 764 }
 765 EXPORT_SYMBOL(ipmi_smi_watcher_register);
 766
 767 int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher)
 768 {
 769         mutex_lock(&smi_watchers_mutex);
 770         list_del(&watcher->link);
 771         mutex_unlock(&smi_watchers_mutex);
 772         return 0;
 773 }
 774 EXPORT_SYMBOL(ipmi_smi_watcher_unregister);
 775
 776 /*
 777  * Must be called with smi_watchers_mutex held.
 778  */
 779 static void
 780 call_smi_watchers(int i, struct device *dev)
 781 {
 782         struct ipmi_smi_watcher *w;
 783
 784         mutex_lock(&smi_watchers_mutex);
 785         list_for_each_entry(w, &smi_watchers, link) {
 786                 if (try_module_get(w->owner)) {
 787                         w->new_smi(i, dev);
 788                         module_put(w->owner);
 789                 }
 790         }
 791         mutex_unlock(&smi_watchers_mutex);
 792 }
 793
 794 static int
 795 ipmi_addr_equal(struct ipmi_addr *addr1, struct ipmi_addr *addr2)
 796 {
 797         if (addr1->addr_type != addr2->addr_type)
 798                 return 0;
 799
 800         if (addr1->channel != addr2->channel)
 801                 return 0;
 802
 803         if (addr1->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
 804                 struct ipmi_system_interface_addr *smi_addr1
 805                     = (struct ipmi_system_interface_addr *) addr1;
 806                 struct ipmi_system_interface_addr *smi_addr2
 807                     = (struct ipmi_system_interface_addr *) addr2;
 808                 return (smi_addr1->lun == smi_addr2->lun);
 809         }
 810
 811         if (is_ipmb_addr(addr1) || is_ipmb_bcast_addr(addr1)) {
 812                 struct ipmi_ipmb_addr *ipmb_addr1
 813                     = (struct ipmi_ipmb_addr *) addr1;
 814                 struct ipmi_ipmb_addr *ipmb_addr2
 815                     = (struct ipmi_ipmb_addr *) addr2;
 816
 817                 return ((ipmb_addr1->slave_addr == ipmb_addr2->slave_addr)
 818                         && (ipmb_addr1->lun == ipmb_addr2->lun));
 819         }
 820
 821         if (is_lan_addr(addr1)) {
 822                 struct ipmi_lan_addr *lan_addr1
 823                         = (struct ipmi_lan_addr *) addr1;
 824                 struct ipmi_lan_addr *lan_addr2
 825                     = (struct ipmi_lan_addr *) addr2;
 826
 827                 return ((lan_addr1->remote_SWID == lan_addr2->remote_SWID)
 828                         && (lan_addr1->local_SWID == lan_addr2->local_SWID)
 829                         && (lan_addr1->session_handle
 830                             == lan_addr2->session_handle)
 831                         && (lan_addr1->lun == lan_addr2->lun));
 832         }
 833
 834         return 1;
 835 }
 836
 837 int ipmi_validate_addr(struct ipmi_addr *addr, int len)
 838 {
 839         if (len < sizeof(struct ipmi_system_interface_addr))
 840                 return -EINVAL;
 841
 842         if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
 843                 if (addr->channel != IPMI_BMC_CHANNEL)
 844                         return -EINVAL;
 845                 return 0;
 846         }
 847
 848         if ((addr->channel == IPMI_BMC_CHANNEL)
 849             || (addr->channel >= IPMI_MAX_CHANNELS)
 850             || (addr->channel < 0))
 851                 return -EINVAL;
 852
 853         if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
 854                 if (len < sizeof(struct ipmi_ipmb_addr))
 855                         return -EINVAL;
 856                 return 0;
 857         }
 858
 859         if (is_lan_addr(addr)) {
 860                 if (len < sizeof(struct ipmi_lan_addr))
 861                         return -EINVAL;
 862                 return 0;
 863         }
 864
 865         return -EINVAL;
 866 }
 867 EXPORT_SYMBOL(ipmi_validate_addr);
 868
 869 unsigned int ipmi_addr_length(int addr_type)
 870 {
 871         if (addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
 872                 return sizeof(struct ipmi_system_interface_addr);
 873
 874         if ((addr_type == IPMI_IPMB_ADDR_TYPE)
 875                         || (addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE))
 876                 return sizeof(struct ipmi_ipmb_addr);
 877
 878         if (addr_type == IPMI_LAN_ADDR_TYPE)
 879                 return sizeof(struct ipmi_lan_addr);
 880
 881         return 0;
 882 }
 883 EXPORT_SYMBOL(ipmi_addr_length);
 884
 885 static int deliver_response(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
 886 {
 887         int rv = 0;
 888
 889         if (!msg->user) {
 890                 /* Special handling for NULL users. */
 891                 if (intf->null_user_handler) {
 892                         intf->null_user_handler(intf, msg);
 893                 } else {
 894                         /* No handler, so give up. */
 895                         rv = -EINVAL;
 896                 }
 897                 ipmi_free_recv_msg(msg);
 898         } else if (oops_in_progress) {
 899                 /*
 900                  * If we are running in the panic context, calling the
 901                  * receive handler doesn't much meaning and has a deadlock
 902                  * risk.  At this moment, simply skip it in that case.
 903                  */
 904                 ipmi_free_recv_msg(msg);
 905         } else {
 906                 int index;
 907                 struct ipmi_user *user = acquire_ipmi_user(msg->user, &index);
 908
 909                 if (user) {
 910                         user->handler->ipmi_recv_hndl(msg, user->handler_data);
 911                         release_ipmi_user(user, index);
 912                 } else {
 913                         /* User went away, give up. */
 914                         ipmi_free_recv_msg(msg);
 915                         rv = -EINVAL;
 916                 }
 917         }
 918
 919         return rv;
 920 }
 921
 922 static void deliver_local_response(struct ipmi_smi *intf,
 923                                    struct ipmi_recv_msg *msg)
 924 {
 925         if (deliver_response(intf, msg))
 926                 ipmi_inc_stat(intf, unhandled_local_responses);
 927         else
 928                 ipmi_inc_stat(intf, handled_local_responses);
 929 }
 930
 931 static void deliver_err_response(struct ipmi_smi *intf,
 932                                  struct ipmi_recv_msg *msg, int err)
 933 {
 934         msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
 935         msg->msg_data[0] = err;
 936         msg->msg.netfn |= 1; /* Convert to a response. */
 937         msg->msg.data_len = 1;
 938         msg->msg.data = msg->msg_data;
 939         deliver_local_response(intf, msg);
 940 }
 941
 942 static void smi_add_watch(struct ipmi_smi *intf, unsigned int flags)
 943 {
 944         unsigned long iflags;
 945
 946         if (!intf->handlers->set_need_watch)
 947                 return;
 948
 949         spin_lock_irqsave(&intf->watch_lock, iflags);
 950         if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
 951                 intf->response_waiters++;
 952
 953         if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
 954                 intf->watchdog_waiters++;
 955
 956         if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
 957                 intf->command_waiters++;
 958
 959         if ((intf->last_watch_mask & flags) != flags) {
 960                 intf->last_watch_mask |= flags;
 961                 intf->handlers->set_need_watch(intf->send_info,
 962                                                intf->last_watch_mask);
 963         }
 964         spin_unlock_irqrestore(&intf->watch_lock, iflags);
 965 }
 966
 967 static void smi_remove_watch(struct ipmi_smi *intf, unsigned int flags)
 968 {
 969         unsigned long iflags;
 970
 971         if (!intf->handlers->set_need_watch)
 972                 return;
 973
 974         spin_lock_irqsave(&intf->watch_lock, iflags);
 975         if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
 976                 intf->response_waiters--;
 977
 978         if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
 979                 intf->watchdog_waiters--;
 980
 981         if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
 982                 intf->command_waiters--;
 983
 984         flags = 0;
 985         if (intf->response_waiters)
 986                 flags |= IPMI_WATCH_MASK_CHECK_MESSAGES;
 987         if (intf->watchdog_waiters)
 988                 flags |= IPMI_WATCH_MASK_CHECK_WATCHDOG;
 989         if (intf->command_waiters)
 990                 flags |= IPMI_WATCH_MASK_CHECK_COMMANDS;
 991
 992         if (intf->last_watch_mask != flags) {
 993                 intf->last_watch_mask = flags;
 994                 intf->handlers->set_need_watch(intf->send_info,
 995                                                intf->last_watch_mask);
 996         }
 997         spin_unlock_irqrestore(&intf->watch_lock, iflags);
 998 }
 999
1000 /*
1001  * Find the next sequence number not being used and add the given
1002  * message with the given timeout to the sequence table.  This must be
1003  * called with the interface's seq_lock held.
1004  */
1005 static int intf_next_seq(struct ipmi_smi      *intf,
1006                          struct ipmi_recv_msg *recv_msg,
1007                          unsigned long        timeout,
1008                          int                  retries,
1009                          int                  broadcast,
1010                          unsigned char        *seq,
1011                          long                 *seqid)
1012 {
1013         int          rv = 0;
1014         unsigned int i;
1015
1016         if (timeout == 0)
1017                 timeout = default_retry_ms;
1018         if (retries < 0)
1019                 retries = default_max_retries;
1020
1021         for (i = intf->curr_seq; (i+1)%IPMI_IPMB_NUM_SEQ != intf->curr_seq;
1022                                         i = (i+1)%IPMI_IPMB_NUM_SEQ) {
1023                 if (!intf->seq_table[i].inuse)
1024                         break;
1025         }
1026
1027         if (!intf->seq_table[i].inuse) {
1028                 intf->seq_table[i].recv_msg = recv_msg;
1029
1030                 /*
1031                  * Start with the maximum timeout, when the send response
1032                  * comes in we will start the real timer.
1033                  */
1034                 intf->seq_table[i].timeout = MAX_MSG_TIMEOUT;
1035                 intf->seq_table[i].orig_timeout = timeout;
1036                 intf->seq_table[i].retries_left = retries;
1037                 intf->seq_table[i].broadcast = broadcast;
1038                 intf->seq_table[i].inuse = 1;
1039                 intf->seq_table[i].seqid = NEXT_SEQID(intf->seq_table[i].seqid);
1040                 *seq = i;
1041                 *seqid = intf->seq_table[i].seqid;
1042                 intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
1043                 smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1044                 need_waiter(intf);
1045         } else {
1046                 rv = -EAGAIN;
1047         }
1048
1049         return rv;
1050 }
1051
1052 /*
1053  * Return the receive message for the given sequence number and
1054  * release the sequence number so it can be reused.  Some other data
1055  * is passed in to be sure the message matches up correctly (to help
1056  * guard against message coming in after their timeout and the
1057  * sequence number being reused).
1058  */
1059 static int intf_find_seq(struct ipmi_smi      *intf,
1060                          unsigned char        seq,
1061                          short                channel,
1062                          unsigned char        cmd,
1063                          unsigned char        netfn,
1064                          struct ipmi_addr     *addr,
1065                          struct ipmi_recv_msg **recv_msg)
1066 {
1067         int           rv = -ENODEV;
1068         unsigned long flags;
1069
1070         if (seq >= IPMI_IPMB_NUM_SEQ)
1071                 return -EINVAL;
1072
1073         spin_lock_irqsave(&intf->seq_lock, flags);
1074         if (intf->seq_table[seq].inuse) {
1075                 struct ipmi_recv_msg *msg = intf->seq_table[seq].recv_msg;
1076
1077                 if ((msg->addr.channel == channel) && (msg->msg.cmd == cmd)
1078                                 && (msg->msg.netfn == netfn)
1079                                 && (ipmi_addr_equal(addr, &msg->addr))) {
1080                         *recv_msg = msg;
1081                         intf->seq_table[seq].inuse = 0;
1082                         smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1083                         rv = 0;
1084                 }
1085         }
1086         spin_unlock_irqrestore(&intf->seq_lock, flags);
1087
1088         return rv;
1089 }
1090
1091
1092 /* Start the timer for a specific sequence table entry. */
1093 static int intf_start_seq_timer(struct ipmi_smi *intf,
1094                                 long       msgid)
1095 {
1096         int           rv = -ENODEV;
1097         unsigned long flags;
1098         unsigned char seq;
1099         unsigned long seqid;
1100
1101
1102         GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1103
1104         spin_lock_irqsave(&intf->seq_lock, flags);
1105         /*
1106          * We do this verification because the user can be deleted
1107          * while a message is outstanding.
1108          */
1109         if ((intf->seq_table[seq].inuse)
1110                                 && (intf->seq_table[seq].seqid == seqid)) {
1111                 struct seq_table *ent = &intf->seq_table[seq];
1112                 ent->timeout = ent->orig_timeout;
1113                 rv = 0;
1114         }
1115         spin_unlock_irqrestore(&intf->seq_lock, flags);
1116
1117         return rv;
1118 }
1119
1120 /* Got an error for the send message for a specific sequence number. */
1121 static int intf_err_seq(struct ipmi_smi *intf,
1122                         long         msgid,
1123                         unsigned int err)
1124 {
1125         int                  rv = -ENODEV;
1126         unsigned long        flags;
1127         unsigned char        seq;
1128         unsigned long        seqid;
1129         struct ipmi_recv_msg *msg = NULL;
1130
1131
1132         GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1133
1134         spin_lock_irqsave(&intf->seq_lock, flags);
1135         /*
1136          * We do this verification because the user can be deleted
1137          * while a message is outstanding.
1138          */
1139         if ((intf->seq_table[seq].inuse)
1140                                 && (intf->seq_table[seq].seqid == seqid)) {
1141                 struct seq_table *ent = &intf->seq_table[seq];
1142
1143                 ent->inuse = 0;
1144                 smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1145                 msg = ent->recv_msg;
1146                 rv = 0;
1147         }
1148         spin_unlock_irqrestore(&intf->seq_lock, flags);
1149
1150         if (msg)
1151                 deliver_err_response(intf, msg, err);
1152
1153         return rv;
1154 }
1155
1156 static void free_user_work(struct work_struct *work)
1157 {
1158         struct ipmi_user *user = container_of(work, struct ipmi_user,
1159                                               remove_work);
1160
1161         cleanup_srcu_struct(&user->release_barrier);
1162         vfree(user);
1163 }
1164
1165 int ipmi_create_user(unsigned int          if_num,
1166                      const struct ipmi_user_hndl *handler,
1167                      void                  *handler_data,
1168                      struct ipmi_user      **user)
1169 {
1170         unsigned long flags;
1171         struct ipmi_user *new_user;
1172         int           rv, index;
1173         struct ipmi_smi *intf;
1174
1175         /*
1176          * There is no module usecount here, because it's not
1177          * required.  Since this can only be used by and called from
1178          * other modules, they will implicitly use this module, and
1179          * thus this can't be removed unless the other modules are
1180          * removed.
1181          */
1182
1183         if (handler == NULL)
1184                 return -EINVAL;
1185
1186         /*
1187          * Make sure the driver is actually initialized, this handles
1188          * problems with initialization order.
1189          */
1190         rv = ipmi_init_msghandler();
1191         if (rv)
1192                 return rv;
1193
1194         new_user = vzalloc(sizeof(*new_user));
1195         if (!new_user)
1196                 return -ENOMEM;
1197
1198         index = srcu_read_lock(&ipmi_interfaces_srcu);
1199         list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
1200                 if (intf->intf_num == if_num)
1201                         goto found;
1202         }
1203         /* Not found, return an error */
1204         rv = -EINVAL;
1205         goto out_kfree;
1206
1207  found:
1208         INIT_WORK(&new_user->remove_work, free_user_work);
1209
1210         rv = init_srcu_struct(&new_user->release_barrier);
1211         if (rv)
1212                 goto out_kfree;
1213
1214         if (!try_module_get(intf->owner)) {
1215                 rv = -ENODEV;
1216                 goto out_kfree;
1217         }
1218
1219         /* Note that each existing user holds a refcount to the interface. */
1220         kref_get(&intf->refcount);
1221
1222         kref_init(&new_user->refcount);
1223         new_user->handler = handler;
1224         new_user->handler_data = handler_data;
1225         new_user->intf = intf;
1226         new_user->gets_events = false;
1227
1228         rcu_assign_pointer(new_user->self, new_user);
1229         spin_lock_irqsave(&intf->seq_lock, flags);
1230         list_add_rcu(&new_user->link, &intf->users);
1231         spin_unlock_irqrestore(&intf->seq_lock, flags);
1232         if (handler->ipmi_watchdog_pretimeout)
1233                 /* User wants pretimeouts, so make sure to watch for them. */
1234                 smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1235         srcu_read_unlock(&ipmi_interfaces_srcu, index);
1236         *user = new_user;
1237         return 0;
1238
1239 out_kfree:
1240         srcu_read_unlock(&ipmi_interfaces_srcu, index);
1241         vfree(new_user);
1242         return rv;
1243 }
1244 EXPORT_SYMBOL(ipmi_create_user);
1245
1246 int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data)
1247 {
1248         int rv, index;
1249         struct ipmi_smi *intf;
1250
1251         index = srcu_read_lock(&ipmi_interfaces_srcu);
1252         list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
1253                 if (intf->intf_num == if_num)
1254                         goto found;
1255         }
1256         srcu_read_unlock(&ipmi_interfaces_srcu, index);
1257
1258         /* Not found, return an error */
1259         return -EINVAL;
1260
1261 found:
1262         if (!intf->handlers->get_smi_info)
1263                 rv = -ENOTTY;
1264         else
1265                 rv = intf->handlers->get_smi_info(intf->send_info, data);
1266         srcu_read_unlock(&ipmi_interfaces_srcu, index);
1267
1268         return rv;
1269 }
1270 EXPORT_SYMBOL(ipmi_get_smi_info);
1271
1272 static void free_user(struct kref *ref)
1273 {
1274         struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount);
1275
1276         /* SRCU cleanup must happen in task context. */
1277         queue_work(remove_work_wq, &user->remove_work);
1278 }
1279
1280 static void _ipmi_destroy_user(struct ipmi_user *user)
1281 {
1282         struct ipmi_smi  *intf = user->intf;
1283         int              i;
1284         unsigned long    flags;
1285         struct cmd_rcvr  *rcvr;
1286         struct cmd_rcvr  *rcvrs = NULL;
1287
1288         if (!acquire_ipmi_user(user, &i)) {
1289                 /*
1290                  * The user has already been cleaned up, just make sure
1291                  * nothing is using it and return.
1292                  */
1293                 synchronize_srcu(&user->release_barrier);
1294                 return;
1295         }
1296
1297         rcu_assign_pointer(user->self, NULL);
1298         release_ipmi_user(user, i);
1299
1300         synchronize_srcu(&user->release_barrier);
1301
1302         if (user->handler->shutdown)
1303                 user->handler->shutdown(user->handler_data);
1304
1305         if (user->handler->ipmi_watchdog_pretimeout)
1306                 smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1307
1308         if (user->gets_events)
1309                 atomic_dec(&intf->event_waiters);
1310
1311         /* Remove the user from the interface's sequence table. */
1312         spin_lock_irqsave(&intf->seq_lock, flags);
1313         list_del_rcu(&user->link);
1314
1315         for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
1316                 if (intf->seq_table[i].inuse
1317                     && (intf->seq_table[i].recv_msg->user == user)) {
1318                         intf->seq_table[i].inuse = 0;
1319                         smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1320                         ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
1321                 }
1322         }
1323         spin_unlock_irqrestore(&intf->seq_lock, flags);
1324
1325         /*
1326          * Remove the user from the command receiver's table.  First
1327          * we build a list of everything (not using the standard link,
1328          * since other things may be using it till we do
1329          * synchronize_srcu()) then free everything in that list.
1330          */
1331         mutex_lock(&intf->cmd_rcvrs_mutex);
1332         list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1333                                 lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1334                 if (rcvr->user == user) {
1335                         list_del_rcu(&rcvr->link);
1336                         rcvr->next = rcvrs;
1337                         rcvrs = rcvr;
1338                 }
1339         }
1340         mutex_unlock(&intf->cmd_rcvrs_mutex);
1341         synchronize_rcu();
1342         while (rcvrs) {
1343                 rcvr = rcvrs;
1344                 rcvrs = rcvr->next;
1345                 kfree(rcvr);
1346         }
1347
1348         kref_put(&intf->refcount, intf_free);
1349         module_put(intf->owner);
1350 }
1351
1352 int ipmi_destroy_user(struct ipmi_user *user)
1353 {
1354         _ipmi_destroy_user(user);
1355
1356         kref_put(&user->refcount, free_user);
1357
1358         return 0;
1359 }
1360 EXPORT_SYMBOL(ipmi_destroy_user);
1361
1362 int ipmi_get_version(struct ipmi_user *user,
1363                      unsigned char *major,
1364                      unsigned char *minor)
1365 {
1366         struct ipmi_device_id id;
1367         int rv, index;
1368
1369         user = acquire_ipmi_user(user, &index);
1370         if (!user)
1371                 return -ENODEV;
1372
1373         rv = bmc_get_device_id(user->intf, NULL, &id, NULL, NULL);
1374         if (!rv) {
1375                 *major = ipmi_version_major(&id);
1376                 *minor = ipmi_version_minor(&id);
1377         }
1378         release_ipmi_user(user, index);
1379
1380         return rv;
1381 }
1382 EXPORT_SYMBOL(ipmi_get_version);
1383
1384 int ipmi_set_my_address(struct ipmi_user *user,
1385                         unsigned int  channel,
1386                         unsigned char address)
1387 {
1388         int index, rv = 0;
1389
1390         user = acquire_ipmi_user(user, &index);
1391         if (!user)
1392                 return -ENODEV;
1393
1394         if (channel >= IPMI_MAX_CHANNELS) {
1395                 rv = -EINVAL;
1396         } else {
1397                 channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1398                 user->intf->addrinfo[channel].address = address;
1399         }
1400         release_ipmi_user(user, index);
1401
1402         return rv;
1403 }
1404 EXPORT_SYMBOL(ipmi_set_my_address);
1405
1406 int ipmi_get_my_address(struct ipmi_user *user,
1407                         unsigned int  channel,
1408                         unsigned char *address)
1409 {
1410         int index, rv = 0;
1411
1412         user = acquire_ipmi_user(user, &index);
1413         if (!user)
1414                 return -ENODEV;
1415
1416         if (channel >= IPMI_MAX_CHANNELS) {
1417                 rv = -EINVAL;
1418         } else {
1419                 channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1420                 *address = user->intf->addrinfo[channel].address;
1421         }
1422         release_ipmi_user(user, index);
1423
1424         return rv;
1425 }
1426 EXPORT_SYMBOL(ipmi_get_my_address);
1427
1428 int ipmi_set_my_LUN(struct ipmi_user *user,
1429                     unsigned int  channel,
1430                     unsigned char LUN)
1431 {
1432         int index, rv = 0;
1433
1434         user = acquire_ipmi_user(user, &index);
1435         if (!user)
1436                 return -ENODEV;
1437
1438         if (channel >= IPMI_MAX_CHANNELS) {
1439                 rv = -EINVAL;
1440         } else {
1441                 channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1442                 user->intf->addrinfo[channel].lun = LUN & 0x3;
1443         }
1444         release_ipmi_user(user, index);
1445
1446         return rv;
1447 }
1448 EXPORT_SYMBOL(ipmi_set_my_LUN);
1449
1450 int ipmi_get_my_LUN(struct ipmi_user *user,
1451                     unsigned int  channel,
1452                     unsigned char *address)
1453 {
1454         int index, rv = 0;
1455
1456         user = acquire_ipmi_user(user, &index);
1457         if (!user)
1458                 return -ENODEV;
1459
1460         if (channel >= IPMI_MAX_CHANNELS) {
1461                 rv = -EINVAL;
1462         } else {
1463                 channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1464                 *address = user->intf->addrinfo[channel].lun;
1465         }
1466         release_ipmi_user(user, index);
1467
1468         return rv;
1469 }
1470 EXPORT_SYMBOL(ipmi_get_my_LUN);
1471
1472 int ipmi_get_maintenance_mode(struct ipmi_user *user)
1473 {
1474         int mode, index;
1475         unsigned long flags;
1476
1477         user = acquire_ipmi_user(user, &index);
1478         if (!user)
1479                 return -ENODEV;
1480
1481         spin_lock_irqsave(&user->intf->maintenance_mode_lock, flags);
1482         mode = user->intf->maintenance_mode;
1483         spin_unlock_irqrestore(&user->intf->maintenance_mode_lock, flags);
1484         release_ipmi_user(user, index);
1485
1486         return mode;
1487 }
1488 EXPORT_SYMBOL(ipmi_get_maintenance_mode);
1489
1490 static void maintenance_mode_update(struct ipmi_smi *intf)
1491 {
1492         if (intf->handlers->set_maintenance_mode)
1493                 intf->handlers->set_maintenance_mode(
1494                         intf->send_info, intf->maintenance_mode_enable);
1495 }
1496
1497 int ipmi_set_maintenance_mode(struct ipmi_user *user, int mode)
1498 {
1499         int rv = 0, index;
1500         unsigned long flags;
1501         struct ipmi_smi *intf = user->intf;
1502
1503         user = acquire_ipmi_user(user, &index);
1504         if (!user)
1505                 return -ENODEV;
1506
1507         spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1508         if (intf->maintenance_mode != mode) {
1509                 switch (mode) {
1510                 case IPMI_MAINTENANCE_MODE_AUTO:
1511                         intf->maintenance_mode_enable
1512                                 = (intf->auto_maintenance_timeout > 0);
1513                         break;
1514
1515                 case IPMI_MAINTENANCE_MODE_OFF:
1516                         intf->maintenance_mode_enable = false;
1517                         break;
1518
1519                 case IPMI_MAINTENANCE_MODE_ON:
1520                         intf->maintenance_mode_enable = true;
1521                         break;
1522
1523                 default:
1524                         rv = -EINVAL;
1525                         goto out_unlock;
1526                 }
1527                 intf->maintenance_mode = mode;
1528
1529                 maintenance_mode_update(intf);
1530         }
1531  out_unlock:
1532         spin_unlock_irqrestore(&intf->maintenance_mode_lock, flags);
1533         release_ipmi_user(user, index);
1534
1535         return rv;
1536 }
1537 EXPORT_SYMBOL(ipmi_set_maintenance_mode);
1538
1539 int ipmi_set_gets_events(struct ipmi_user *user, bool val)
1540 {
1541         unsigned long        flags;
1542         struct ipmi_smi      *intf = user->intf;
1543         struct ipmi_recv_msg *msg, *msg2;
1544         struct list_head     msgs;
1545         int index;
1546
1547         user = acquire_ipmi_user(user, &index);
1548         if (!user)
1549                 return -ENODEV;
1550
1551         INIT_LIST_HEAD(&msgs);
1552
1553         spin_lock_irqsave(&intf->events_lock, flags);
1554         if (user->gets_events == val)
1555                 goto out;
1556
1557         user->gets_events = val;
1558
1559         if (val) {
1560                 if (atomic_inc_return(&intf->event_waiters) == 1)
1561                         need_waiter(intf);
1562         } else {
1563                 atomic_dec(&intf->event_waiters);
1564         }
1565
1566         if (intf->delivering_events)
1567                 /*
1568                  * Another thread is delivering events for this, so
1569                  * let it handle any new events.
1570                  */
1571                 goto out;
1572
1573         /* Deliver any queued events. */
1574         while (user->gets_events && !list_empty(&intf->waiting_events)) {
1575                 list_for_each_entry_safe(msg, msg2, &intf->waiting_events, link)
1576                         list_move_tail(&msg->link, &msgs);
1577                 intf->waiting_events_count = 0;
1578                 if (intf->event_msg_printed) {
1579                         dev_warn(intf->si_dev, "Event queue no longer full\n");
1580                         intf->event_msg_printed = 0;
1581                 }
1582
1583                 intf->delivering_events = 1;
1584                 spin_unlock_irqrestore(&intf->events_lock, flags);
1585
1586                 list_for_each_entry_safe(msg, msg2, &msgs, link) {
1587                         msg->user = user;
1588                         kref_get(&user->refcount);
1589                         deliver_local_response(intf, msg);
1590                 }
1591
1592                 spin_lock_irqsave(&intf->events_lock, flags);
1593                 intf->delivering_events = 0;
1594         }
1595
1596  out:
1597         spin_unlock_irqrestore(&intf->events_lock, flags);
1598         release_ipmi_user(user, index);
1599
1600         return 0;
1601 }
1602 EXPORT_SYMBOL(ipmi_set_gets_events);
1603
1604 static struct cmd_rcvr *find_cmd_rcvr(struct ipmi_smi *intf,
1605                                       unsigned char netfn,
1606                                       unsigned char cmd,
1607                                       unsigned char chan)
1608 {
1609         struct cmd_rcvr *rcvr;
1610
1611         list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1612                                 lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1613                 if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1614                                         && (rcvr->chans & (1 << chan)))
1615                         return rcvr;
1616         }
1617         return NULL;
1618 }
1619
1620 static int is_cmd_rcvr_exclusive(struct ipmi_smi *intf,
1621                                  unsigned char netfn,
1622                                  unsigned char cmd,
1623                                  unsigned int  chans)
1624 {
1625         struct cmd_rcvr *rcvr;
1626
1627         list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1628                                 lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1629                 if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1630                                         && (rcvr->chans & chans))
1631                         return 0;
1632         }
1633         return 1;
1634 }
1635
1636 int ipmi_register_for_cmd(struct ipmi_user *user,
1637                           unsigned char netfn,
1638                           unsigned char cmd,
1639                           unsigned int  chans)
1640 {
1641         struct ipmi_smi *intf = user->intf;
1642         struct cmd_rcvr *rcvr;
1643         int rv = 0, index;
1644
1645         user = acquire_ipmi_user(user, &index);
1646         if (!user)
1647                 return -ENODEV;
1648
1649         rcvr = kmalloc(sizeof(*rcvr), GFP_KERNEL);
1650         if (!rcvr) {
1651                 rv = -ENOMEM;
1652                 goto out_release;
1653         }
1654         rcvr->cmd = cmd;
1655         rcvr->netfn = netfn;
1656         rcvr->chans = chans;
1657         rcvr->user = user;
1658
1659         mutex_lock(&intf->cmd_rcvrs_mutex);
1660         /* Make sure the command/netfn is not already registered. */
1661         if (!is_cmd_rcvr_exclusive(intf, netfn, cmd, chans)) {
1662                 rv = -EBUSY;
1663                 goto out_unlock;
1664         }
1665
1666         smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1667
1668         list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
1669
1670 out_unlock:
1671         mutex_unlock(&intf->cmd_rcvrs_mutex);
1672         if (rv)
1673                 kfree(rcvr);
1674 out_release:
1675         release_ipmi_user(user, index);
1676
1677         return rv;
1678 }
1679 EXPORT_SYMBOL(ipmi_register_for_cmd);
1680
1681 int ipmi_unregister_for_cmd(struct ipmi_user *user,
1682                             unsigned char netfn,
1683                             unsigned char cmd,
1684                             unsigned int  chans)
1685 {
1686         struct ipmi_smi *intf = user->intf;
1687         struct cmd_rcvr *rcvr;
1688         struct cmd_rcvr *rcvrs = NULL;
1689         int i, rv = -ENOENT, index;
1690
1691         user = acquire_ipmi_user(user, &index);
1692         if (!user)
1693                 return -ENODEV;
1694
1695         mutex_lock(&intf->cmd_rcvrs_mutex);
1696         for (i = 0; i < IPMI_NUM_CHANNELS; i++) {
1697                 if (((1 << i) & chans) == 0)
1698                         continue;
1699                 rcvr = find_cmd_rcvr(intf, netfn, cmd, i);
1700                 if (rcvr == NULL)
1701                         continue;
1702                 if (rcvr->user == user) {
1703                         rv = 0;
1704                         rcvr->chans &= ~chans;
1705                         if (rcvr->chans == 0) {
1706                                 list_del_rcu(&rcvr->link);
1707                                 rcvr->next = rcvrs;
1708                                 rcvrs = rcvr;
1709                         }
1710                 }
1711         }
1712         mutex_unlock(&intf->cmd_rcvrs_mutex);
1713         synchronize_rcu();
1714         release_ipmi_user(user, index);
1715         while (rcvrs) {
1716                 smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1717                 rcvr = rcvrs;
1718                 rcvrs = rcvr->next;
1719                 kfree(rcvr);
1720         }
1721
1722         return rv;
1723 }
1724 EXPORT_SYMBOL(ipmi_unregister_for_cmd);
1725
1726 static unsigned char
1727 ipmb_checksum(unsigned char *data, int size)
1728 {
1729         unsigned char csum = 0;
1730
1731         for (; size > 0; size--, data++)
1732                 csum += *data;
1733
1734         return -csum;
1735 }
1736
1737 static inline void format_ipmb_msg(struct ipmi_smi_msg   *smi_msg,
1738                                    struct kernel_ipmi_msg *msg,
1739                                    struct ipmi_ipmb_addr *ipmb_addr,
1740                                    long                  msgid,
1741                                    unsigned char         ipmb_seq,
1742                                    int                   broadcast,
1743                                    unsigned char         source_address,
1744                                    unsigned char         source_lun)
1745 {
1746         int i = broadcast;
1747
1748         /* Format the IPMB header data. */
1749         smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1750         smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1751         smi_msg->data[2] = ipmb_addr->channel;
1752         if (broadcast)
1753                 smi_msg->data[3] = 0;
1754         smi_msg->data[i+3] = ipmb_addr->slave_addr;
1755         smi_msg->data[i+4] = (msg->netfn << 2) | (ipmb_addr->lun & 0x3);
1756         smi_msg->data[i+5] = ipmb_checksum(&smi_msg->data[i + 3], 2);
1757         smi_msg->data[i+6] = source_address;
1758         smi_msg->data[i+7] = (ipmb_seq << 2) | source_lun;
1759         smi_msg->data[i+8] = msg->cmd;
1760
1761         /* Now tack on the data to the message. */
1762         if (msg->data_len > 0)
1763                 memcpy(&smi_msg->data[i + 9], msg->data, msg->data_len);
1764         smi_msg->data_size = msg->data_len + 9;
1765
1766         /* Now calculate the checksum and tack it on. */
1767         smi_msg->data[i+smi_msg->data_size]
1768                 = ipmb_checksum(&smi_msg->data[i + 6], smi_msg->data_size - 6);
1769
1770         /*
1771          * Add on the checksum size and the offset from the
1772          * broadcast.
1773          */
1774         smi_msg->data_size += 1 + i;
1775
1776         smi_msg->msgid = msgid;
1777 }
1778
1779 static inline void format_lan_msg(struct ipmi_smi_msg   *smi_msg,
1780                                   struct kernel_ipmi_msg *msg,
1781                                   struct ipmi_lan_addr  *lan_addr,
1782                                   long                  msgid,
1783                                   unsigned char         ipmb_seq,
1784                                   unsigned char         source_lun)
1785 {
1786         /* Format the IPMB header data. */
1787         smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1788         smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1789         smi_msg->data[2] = lan_addr->channel;
1790         smi_msg->data[3] = lan_addr->session_handle;
1791         smi_msg->data[4] = lan_addr->remote_SWID;
1792         smi_msg->data[5] = (msg->netfn << 2) | (lan_addr->lun & 0x3);
1793         smi_msg->data[6] = ipmb_checksum(&smi_msg->data[4], 2);
1794         smi_msg->data[7] = lan_addr->local_SWID;
1795         smi_msg->data[8] = (ipmb_seq << 2) | source_lun;
1796         smi_msg->data[9] = msg->cmd;
1797
1798         /* Now tack on the data to the message. */
1799         if (msg->data_len > 0)
1800                 memcpy(&smi_msg->data[10], msg->data, msg->data_len);
1801         smi_msg->data_size = msg->data_len + 10;
1802
1803         /* Now calculate the checksum and tack it on. */
1804         smi_msg->data[smi_msg->data_size]
1805                 = ipmb_checksum(&smi_msg->data[7], smi_msg->data_size - 7);
1806
1807         /*
1808          * Add on the checksum size and the offset from the
1809          * broadcast.
1810          */
1811         smi_msg->data_size += 1;
1812
1813         smi_msg->msgid = msgid;
1814 }
1815
1816 static struct ipmi_smi_msg *smi_add_send_msg(struct ipmi_smi *intf,
1817                                              struct ipmi_smi_msg *smi_msg,
1818                                              int priority)
1819 {
1820         if (intf->curr_msg) {
1821                 if (priority > 0)
1822                         list_add_tail(&smi_msg->link, &intf->hp_xmit_msgs);
1823                 else
1824                         list_add_tail(&smi_msg->link, &intf->xmit_msgs);
1825                 smi_msg = NULL;
1826         } else {
1827                 intf->curr_msg = smi_msg;
1828         }
1829
1830         return smi_msg;
1831 }
1832
1833 static void smi_send(struct ipmi_smi *intf,
1834                      const struct ipmi_smi_handlers *handlers,
1835                      struct ipmi_smi_msg *smi_msg, int priority)
1836 {
1837         int run_to_completion = intf->run_to_completion;
1838         unsigned long flags = 0;
1839
1840         if (!run_to_completion)
1841                 spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
1842         smi_msg = smi_add_send_msg(intf, smi_msg, priority);
1843
1844         if (!run_to_completion)
1845                 spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
1846
1847         if (smi_msg)
1848                 handlers->sender(intf->send_info, smi_msg);
1849 }
1850
1851 static bool is_maintenance_mode_cmd(struct kernel_ipmi_msg *msg)
1852 {
1853         return (((msg->netfn == IPMI_NETFN_APP_REQUEST)
1854                  && ((msg->cmd == IPMI_COLD_RESET_CMD)
1855                      || (msg->cmd == IPMI_WARM_RESET_CMD)))
1856                 || (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST));
1857 }
1858
1859 static int i_ipmi_req_sysintf(struct ipmi_smi        *intf,
1860                               struct ipmi_addr       *addr,
1861                               long                   msgid,
1862                               struct kernel_ipmi_msg *msg,
1863                               struct ipmi_smi_msg    *smi_msg,
1864                               struct ipmi_recv_msg   *recv_msg,
1865                               int                    retries,
1866                               unsigned int           retry_time_ms)
1867 {
1868         struct ipmi_system_interface_addr *smi_addr;
1869
1870         if (msg->netfn & 1)
1871                 /* Responses are not allowed to the SMI. */
1872                 return -EINVAL;
1873
1874         smi_addr = (struct ipmi_system_interface_addr *) addr;
1875         if (smi_addr->lun > 3) {
1876                 ipmi_inc_stat(intf, sent_invalid_commands);
1877                 return -EINVAL;
1878         }
1879
1880         memcpy(&recv_msg->addr, smi_addr, sizeof(*smi_addr));
1881
1882         if ((msg->netfn == IPMI_NETFN_APP_REQUEST)
1883             && ((msg->cmd == IPMI_SEND_MSG_CMD)
1884                 || (msg->cmd == IPMI_GET_MSG_CMD)
1885                 || (msg->cmd == IPMI_READ_EVENT_MSG_BUFFER_CMD))) {
1886                 /*
1887                  * We don't let the user do these, since we manage
1888                  * the sequence numbers.
1889                  */
1890                 ipmi_inc_stat(intf, sent_invalid_commands);
1891                 return -EINVAL;
1892         }
1893
1894         if (is_maintenance_mode_cmd(msg)) {
1895                 unsigned long flags;
1896
1897                 spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1898                 intf->auto_maintenance_timeout
1899                         = maintenance_mode_timeout_ms;
1900                 if (!intf->maintenance_mode
1901                     && !intf->maintenance_mode_enable) {
1902                         intf->maintenance_mode_enable = true;
1903                         maintenance_mode_update(intf);
1904                 }
1905                 spin_unlock_irqrestore(&intf->maintenance_mode_lock,
1906                                        flags);
1907         }
1908
1909         if (msg->data_len + 2 > IPMI_MAX_MSG_LENGTH) {
1910                 ipmi_inc_stat(intf, sent_invalid_commands);
1911                 return -EMSGSIZE;
1912         }
1913
1914         smi_msg->data[0] = (msg->netfn << 2) | (smi_addr->lun & 0x3);
1915         smi_msg->data[1] = msg->cmd;
1916         smi_msg->msgid = msgid;
1917         smi_msg->user_data = recv_msg;
1918         if (msg->data_len > 0)
1919                 memcpy(&smi_msg->data[2], msg->data, msg->data_len);
1920         smi_msg->data_size = msg->data_len + 2;
1921         ipmi_inc_stat(intf, sent_local_commands);
1922
1923         return 0;
1924 }
1925
1926 static int i_ipmi_req_ipmb(struct ipmi_smi        *intf,
1927                            struct ipmi_addr       *addr,
1928                            long                   msgid,
1929                            struct kernel_ipmi_msg *msg,
1930                            struct ipmi_smi_msg    *smi_msg,
1931                            struct ipmi_recv_msg   *recv_msg,
1932                            unsigned char          source_address,
1933                            unsigned char          source_lun,
1934                            int                    retries,
1935                            unsigned int           retry_time_ms)
1936 {
1937         struct ipmi_ipmb_addr *ipmb_addr;
1938         unsigned char ipmb_seq;
1939         long seqid;
1940         int broadcast = 0;
1941         struct ipmi_channel *chans;
1942         int rv = 0;
1943
1944         if (addr->channel >= IPMI_MAX_CHANNELS) {
1945                 ipmi_inc_stat(intf, sent_invalid_commands);
1946                 return -EINVAL;
1947         }
1948
1949         chans = READ_ONCE(intf->channel_list)->c;
1950
1951         if (chans[addr->channel].medium != IPMI_CHANNEL_MEDIUM_IPMB) {
1952                 ipmi_inc_stat(intf, sent_invalid_commands);
1953                 return -EINVAL;
1954         }
1955
1956         if (addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE) {
1957                 /*
1958                  * Broadcasts add a zero at the beginning of the
1959                  * message, but otherwise is the same as an IPMB
1960                  * address.
1961                  */
1962                 addr->addr_type = IPMI_IPMB_ADDR_TYPE;
1963                 broadcast = 1;
1964                 retries = 0; /* Don't retry broadcasts. */
1965         }
1966
1967         /*
1968          * 9 for the header and 1 for the checksum, plus
1969          * possibly one for the broadcast.
1970          */
1971         if ((msg->data_len + 10 + broadcast) > IPMI_MAX_MSG_LENGTH) {
1972                 ipmi_inc_stat(intf, sent_invalid_commands);
1973                 return -EMSGSIZE;
1974         }
1975
1976         ipmb_addr = (struct ipmi_ipmb_addr *) addr;
1977         if (ipmb_addr->lun > 3) {
1978                 ipmi_inc_stat(intf, sent_invalid_commands);
1979                 return -EINVAL;
1980         }
1981
1982         memcpy(&recv_msg->addr, ipmb_addr, sizeof(*ipmb_addr));
1983
1984         if (recv_msg->msg.netfn & 0x1) {
1985                 /*
1986                  * It's a response, so use the user's sequence
1987                  * from msgid.
1988                  */
1989                 ipmi_inc_stat(intf, sent_ipmb_responses);
1990                 format_ipmb_msg(smi_msg, msg, ipmb_addr, msgid,
1991                                 msgid, broadcast,
1992                                 source_address, source_lun);
1993
1994                 /*
1995                  * Save the receive message so we can use it
1996                  * to deliver the response.
1997                  */
1998                 smi_msg->user_data = recv_msg;
1999         } else {
2000                 /* It's a command, so get a sequence for it. */
2001                 unsigned long flags;
2002
2003                 spin_lock_irqsave(&intf->seq_lock, flags);
2004
2005                 if (is_maintenance_mode_cmd(msg))
2006                         intf->ipmb_maintenance_mode_timeout =
2007                                 maintenance_mode_timeout_ms;
2008
2009                 if (intf->ipmb_maintenance_mode_timeout && retry_time_ms == 0)
2010                         /* Different default in maintenance mode */
2011                         retry_time_ms = default_maintenance_retry_ms;
2012
2013                 /*
2014                  * Create a sequence number with a 1 second
2015                  * timeout and 4 retries.
2016                  */
2017                 rv = intf_next_seq(intf,
2018                                    recv_msg,
2019                                    retry_time_ms,
2020                                    retries,
2021                                    broadcast,
2022                                    &ipmb_seq,
2023                                    &seqid);
2024                 if (rv)
2025                         /*
2026                          * We have used up all the sequence numbers,
2027                          * probably, so abort.
2028                          */
2029                         goto out_err;
2030
2031                 ipmi_inc_stat(intf, sent_ipmb_commands);
2032
2033                 /*
2034                  * Store the sequence number in the message,
2035                  * so that when the send message response
2036                  * comes back we can start the timer.
2037                  */
2038                 format_ipmb_msg(smi_msg, msg, ipmb_addr,
2039                                 STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2040                                 ipmb_seq, broadcast,
2041                                 source_address, source_lun);
2042
2043                 /*
2044                  * Copy the message into the recv message data, so we
2045                  * can retransmit it later if necessary.
2046                  */
2047                 memcpy(recv_msg->msg_data, smi_msg->data,
2048                        smi_msg->data_size);
2049                 recv_msg->msg.data = recv_msg->msg_data;
2050                 recv_msg->msg.data_len = smi_msg->data_size;
2051
2052                 /*
2053                  * We don't unlock until here, because we need
2054                  * to copy the completed message into the
2055                  * recv_msg before we release the lock.
2056                  * Otherwise, race conditions may bite us.  I
2057                  * know that's pretty paranoid, but I prefer
2058                  * to be correct.
2059                  */
2060 out_err:
2061                 spin_unlock_irqrestore(&intf->seq_lock, flags);
2062         }
2063
2064         return rv;
2065 }
2066
2067 static int i_ipmi_req_lan(struct ipmi_smi        *intf,
2068                           struct ipmi_addr       *addr,
2069                           long                   msgid,
2070                           struct kernel_ipmi_msg *msg,
2071                           struct ipmi_smi_msg    *smi_msg,
2072                           struct ipmi_recv_msg   *recv_msg,
2073                           unsigned char          source_lun,
2074                           int                    retries,
2075                           unsigned int           retry_time_ms)
2076 {
2077         struct ipmi_lan_addr  *lan_addr;
2078         unsigned char ipmb_seq;
2079         long seqid;
2080         struct ipmi_channel *chans;
2081         int rv = 0;
2082
2083         if (addr->channel >= IPMI_MAX_CHANNELS) {
2084                 ipmi_inc_stat(intf, sent_invalid_commands);
2085                 return -EINVAL;
2086         }
2087
2088         chans = READ_ONCE(intf->channel_list)->c;
2089
2090         if ((chans[addr->channel].medium
2091                                 != IPMI_CHANNEL_MEDIUM_8023LAN)
2092                         && (chans[addr->channel].medium
2093                             != IPMI_CHANNEL_MEDIUM_ASYNC)) {
2094                 ipmi_inc_stat(intf, sent_invalid_commands);
2095                 return -EINVAL;
2096         }
2097
2098         /* 11 for the header and 1 for the checksum. */
2099         if ((msg->data_len + 12) > IPMI_MAX_MSG_LENGTH) {
2100                 ipmi_inc_stat(intf, sent_invalid_commands);
2101                 return -EMSGSIZE;
2102         }
2103
2104         lan_addr = (struct ipmi_lan_addr *) addr;
2105         if (lan_addr->lun > 3) {
2106                 ipmi_inc_stat(intf, sent_invalid_commands);
2107                 return -EINVAL;
2108         }
2109
2110         memcpy(&recv_msg->addr, lan_addr, sizeof(*lan_addr));
2111
2112         if (recv_msg->msg.netfn & 0x1) {
2113                 /*
2114                  * It's a response, so use the user's sequence
2115                  * from msgid.
2116                  */
2117                 ipmi_inc_stat(intf, sent_lan_responses);
2118                 format_lan_msg(smi_msg, msg, lan_addr, msgid,
2119                                msgid, source_lun);
2120
2121                 /*
2122                  * Save the receive message so we can use it
2123                  * to deliver the response.
2124                  */
2125                 smi_msg->user_data = recv_msg;
2126         } else {
2127                 /* It's a command, so get a sequence for it. */
2128                 unsigned long flags;
2129
2130                 spin_lock_irqsave(&intf->seq_lock, flags);
2131
2132                 /*
2133                  * Create a sequence number with a 1 second
2134                  * timeout and 4 retries.
2135                  */
2136                 rv = intf_next_seq(intf,
2137                                    recv_msg,
2138                                    retry_time_ms,
2139                                    retries,
2140                                    0,
2141                                    &ipmb_seq,
2142                                    &seqid);
2143                 if (rv)
2144                         /*
2145                          * We have used up all the sequence numbers,
2146                          * probably, so abort.
2147                          */
2148                         goto out_err;
2149
2150                 ipmi_inc_stat(intf, sent_lan_commands);
2151
2152                 /*
2153                  * Store the sequence number in the message,
2154                  * so that when the send message response
2155                  * comes back we can start the timer.
2156                  */
2157                 format_lan_msg(smi_msg, msg, lan_addr,
2158                                STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2159                                ipmb_seq, source_lun);
2160
2161                 /*
2162                  * Copy the message into the recv message data, so we
2163                  * can retransmit it later if necessary.
2164                  */
2165                 memcpy(recv_msg->msg_data, smi_msg->data,
2166                        smi_msg->data_size);
2167                 recv_msg->msg.data = recv_msg->msg_data;
2168                 recv_msg->msg.data_len = smi_msg->data_size;
2169
2170                 /*
2171                  * We don't unlock until here, because we need
2172                  * to copy the completed message into the
2173                  * recv_msg before we release the lock.
2174                  * Otherwise, race conditions may bite us.  I
2175                  * know that's pretty paranoid, but I prefer
2176                  * to be correct.
2177                  */
2178 out_err:
2179                 spin_unlock_irqrestore(&intf->seq_lock, flags);
2180         }
2181
2182         return rv;
2183 }
2184
2185 /*
2186  * Separate from ipmi_request so that the user does not have to be
2187  * supplied in certain circumstances (mainly at panic time).  If
2188  * messages are supplied, they will be freed, even if an error
2189  * occurs.
2190  */
2191 static int i_ipmi_request(struct ipmi_user     *user,
2192                           struct ipmi_smi      *intf,
2193                           struct ipmi_addr     *addr,
2194                           long                 msgid,
2195                           struct kernel_ipmi_msg *msg,
2196                           void                 *user_msg_data,
2197                           void                 *supplied_smi,
2198                           struct ipmi_recv_msg *supplied_recv,
2199                           int                  priority,
2200                           unsigned char        source_address,
2201                           unsigned char        source_lun,
2202                           int                  retries,
2203                           unsigned int         retry_time_ms)
2204 {
2205         struct ipmi_smi_msg *smi_msg;
2206         struct ipmi_recv_msg *recv_msg;
2207         int rv = 0;
2208
2209         if (supplied_recv)
2210                 recv_msg = supplied_recv;
2211         else {
2212                 recv_msg = ipmi_alloc_recv_msg();
2213                 if (recv_msg == NULL) {
2214                         rv = -ENOMEM;
2215                         goto out;
2216                 }
2217         }
2218         recv_msg->user_msg_data = user_msg_data;
2219
2220         if (supplied_smi)
2221                 smi_msg = (struct ipmi_smi_msg *) supplied_smi;
2222         else {
2223                 smi_msg = ipmi_alloc_smi_msg();
2224                 if (smi_msg == NULL) {
2225                         if (!supplied_recv)
2226                                 ipmi_free_recv_msg(recv_msg);
2227                         rv = -ENOMEM;
2228                         goto out;
2229                 }
2230         }
2231
2232         rcu_read_lock();
2233         if (intf->in_shutdown) {
2234                 rv = -ENODEV;
2235                 goto out_err;
2236         }
2237
2238         recv_msg->user = user;
2239         if (user)
2240                 /* The put happens when the message is freed. */
2241                 kref_get(&user->refcount);
2242         recv_msg->msgid = msgid;
2243         /*
2244          * Store the message to send in the receive message so timeout
2245          * responses can get the proper response data.
2246          */
2247         recv_msg->msg = *msg;
2248
2249         if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
2250                 rv = i_ipmi_req_sysintf(intf, addr, msgid, msg, smi_msg,
2251                                         recv_msg, retries, retry_time_ms);
2252         } else if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
2253                 rv = i_ipmi_req_ipmb(intf, addr, msgid, msg, smi_msg, recv_msg,
2254                                      source_address, source_lun,
2255                                      retries, retry_time_ms);
2256         } else if (is_lan_addr(addr)) {
2257                 rv = i_ipmi_req_lan(intf, addr, msgid, msg, smi_msg, recv_msg,
2258                                     source_lun, retries, retry_time_ms);
2259         } else {
2260             /* Unknown address type. */
2261                 ipmi_inc_stat(intf, sent_invalid_commands);
2262                 rv = -EINVAL;
2263         }
2264
2265         if (rv) {
2266 out_err:
2267                 ipmi_free_smi_msg(smi_msg);
2268                 ipmi_free_recv_msg(recv_msg);
2269         } else {
2270                 pr_debug("Send: %*ph\n", smi_msg->data_size, smi_msg->data);
2271
2272                 smi_send(intf, intf->handlers, smi_msg, priority);
2273         }
2274         rcu_read_unlock();
2275
2276 out:
2277         return rv;
2278 }
2279
2280 static int check_addr(struct ipmi_smi  *intf,
2281                       struct ipmi_addr *addr,
2282                       unsigned char    *saddr,
2283                       unsigned char    *lun)
2284 {
2285         if (addr->channel >= IPMI_MAX_CHANNELS)
2286                 return -EINVAL;
2287         addr->channel = array_index_nospec(addr->channel, IPMI_MAX_CHANNELS);
2288         *lun = intf->addrinfo[addr->channel].lun;
2289         *saddr = intf->addrinfo[addr->channel].address;
2290         return 0;
2291 }
2292
2293 int ipmi_request_settime(struct ipmi_user *user,
2294                          struct ipmi_addr *addr,
2295                          long             msgid,
2296                          struct kernel_ipmi_msg  *msg,
2297                          void             *user_msg_data,
2298                          int              priority,
2299                          int              retries,
2300                          unsigned int     retry_time_ms)
2301 {
2302         unsigned char saddr = 0, lun = 0;
2303         int rv, index;
2304
2305         if (!user)
2306                 return -EINVAL;
2307
2308         user = acquire_ipmi_user(user, &index);
2309         if (!user)
2310                 return -ENODEV;
2311
2312         rv = check_addr(user->intf, addr, &saddr, &lun);
2313         if (!rv)
2314                 rv = i_ipmi_request(user,
2315                                     user->intf,
2316                                     addr,
2317                                     msgid,
2318                                     msg,
2319                                     user_msg_data,
2320                                     NULL, NULL,
2321                                     priority,
2322                                     saddr,
2323                                     lun,
2324                                     retries,
2325                                     retry_time_ms);
2326
2327         release_ipmi_user(user, index);
2328         return rv;
2329 }
2330 EXPORT_SYMBOL(ipmi_request_settime);
2331
2332 int ipmi_request_supply_msgs(struct ipmi_user     *user,
2333                              struct ipmi_addr     *addr,
2334                              long                 msgid,
2335                              struct kernel_ipmi_msg *msg,
2336                              void                 *user_msg_data,
2337                              void                 *supplied_smi,
2338                              struct ipmi_recv_msg *supplied_recv,
2339                              int                  priority)
2340 {
2341         unsigned char saddr = 0, lun = 0;
2342         int rv, index;
2343
2344         if (!user)
2345                 return -EINVAL;
2346
2347         user = acquire_ipmi_user(user, &index);
2348         if (!user)
2349                 return -ENODEV;
2350
2351         rv = check_addr(user->intf, addr, &saddr, &lun);
2352         if (!rv)
2353                 rv = i_ipmi_request(user,
2354                                     user->intf,
2355                                     addr,
2356                                     msgid,
2357                                     msg,
2358                                     user_msg_data,
2359                                     supplied_smi,
2360                                     supplied_recv,
2361                                     priority,
2362                                     saddr,
2363                                     lun,
2364                                     -1, 0);
2365
2366         release_ipmi_user(user, index);
2367         return rv;
2368 }
2369 EXPORT_SYMBOL(ipmi_request_supply_msgs);
2370
2371 static void bmc_device_id_handler(struct ipmi_smi *intf,
2372                                   struct ipmi_recv_msg *msg)
2373 {
2374         int rv;
2375
2376         if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
2377                         || (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
2378                         || (msg->msg.cmd != IPMI_GET_DEVICE_ID_CMD)) {
2379                 dev_warn(intf->si_dev,
2380                          "invalid device_id msg: addr_type=%d netfn=%x cmd=%x\n",
2381                          msg->addr.addr_type, msg->msg.netfn, msg->msg.cmd);
2382                 return;
2383         }
2384
2385         rv = ipmi_demangle_device_id(msg->msg.netfn, msg->msg.cmd,
2386                         msg->msg.data, msg->msg.data_len, &intf->bmc->fetch_id);
2387         if (rv) {
2388                 dev_warn(intf->si_dev, "device id demangle failed: %d\n", rv);
2389                 /* record completion code when error */
2390                 intf->bmc->cc = msg->msg.data[0];
2391                 intf->bmc->dyn_id_set = 0;
2392         } else {
2393                 /*
2394                  * Make sure the id data is available before setting
2395                  * dyn_id_set.
2396                  */
2397                 smp_wmb();
2398                 intf->bmc->dyn_id_set = 1;
2399         }
2400
2401         wake_up(&intf->waitq);
2402 }
2403
2404 static int
2405 send_get_device_id_cmd(struct ipmi_smi *intf)
2406 {
2407         struct ipmi_system_interface_addr si;
2408         struct kernel_ipmi_msg msg;
2409
2410         si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
2411         si.channel = IPMI_BMC_CHANNEL;
2412         si.lun = 0;
2413
2414         msg.netfn = IPMI_NETFN_APP_REQUEST;
2415         msg.cmd = IPMI_GET_DEVICE_ID_CMD;
2416         msg.data = NULL;
2417         msg.data_len = 0;
2418
2419         return i_ipmi_request(NULL,
2420                               intf,
2421                               (struct ipmi_addr *) &si,
2422                               0,
2423                               &msg,
2424                               intf,
2425                               NULL,
2426                               NULL,
2427                               0,
2428                               intf->addrinfo[0].address,
2429                               intf->addrinfo[0].lun,
2430                               -1, 0);
2431 }
2432
2433 static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
2434 {
2435         int rv;
2436         unsigned int retry_count = 0;
2437
2438         intf->null_user_handler = bmc_device_id_handler;
2439
2440 retry:
2441         bmc->cc = 0;
2442         bmc->dyn_id_set = 2;
2443
2444         rv = send_get_device_id_cmd(intf);
2445         if (rv)
2446                 goto out_reset_handler;
2447
2448         wait_event(intf->waitq, bmc->dyn_id_set != 2);
2449
2450         if (!bmc->dyn_id_set) {
2451                 if ((bmc->cc == IPMI_DEVICE_IN_FW_UPDATE_ERR
2452                      || bmc->cc ==  IPMI_DEVICE_IN_INIT_ERR
2453                      || bmc->cc ==  IPMI_NOT_IN_MY_STATE_ERR)
2454                      && ++retry_count <= GET_DEVICE_ID_MAX_RETRY) {
2455                         msleep(500);
2456                         dev_warn(intf->si_dev,
2457                             "BMC returned 0x%2.2x, retry get bmc device id\n",
2458                             bmc->cc);
2459                         goto retry;
2460                 }
2461
2462                 rv = -EIO; /* Something went wrong in the fetch. */
2463         }
2464
2465         /* dyn_id_set makes the id data available. */
2466         smp_rmb();
2467
2468 out_reset_handler:
2469         intf->null_user_handler = NULL;
2470
2471         return rv;
2472 }
2473
2474 /*
2475  * Fetch the device id for the bmc/interface.  You must pass in either
2476  * bmc or intf, this code will get the other one.  If the data has
2477  * been recently fetched, this will just use the cached data.  Otherwise
2478  * it will run a new fetch.
2479  *
2480  * Except for the first time this is called (in ipmi_add_smi()),
2481  * this will always return good data;
2482  */
2483 static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2484                                struct ipmi_device_id *id,
2485                                bool *guid_set, guid_t *guid, int intf_num)
2486 {
2487         int rv = 0;
2488         int prev_dyn_id_set, prev_guid_set;
2489         bool intf_set = intf != NULL;
2490
2491         if (!intf) {
2492                 mutex_lock(&bmc->dyn_mutex);
2493 retry_bmc_lock:
2494                 if (list_empty(&bmc->intfs)) {
2495                         mutex_unlock(&bmc->dyn_mutex);
2496                         return -ENOENT;
2497                 }
2498                 intf = list_first_entry(&bmc->intfs, struct ipmi_smi,
2499                                         bmc_link);
2500                 kref_get(&intf->refcount);
2501                 mutex_unlock(&bmc->dyn_mutex);
2502                 mutex_lock(&intf->bmc_reg_mutex);
2503                 mutex_lock(&bmc->dyn_mutex);
2504                 if (intf != list_first_entry(&bmc->intfs, struct ipmi_smi,
2505                                              bmc_link)) {
2506                         mutex_unlock(&intf->bmc_reg_mutex);
2507                         kref_put(&intf->refcount, intf_free);
2508                         goto retry_bmc_lock;
2509                 }
2510         } else {
2511                 mutex_lock(&intf->bmc_reg_mutex);
2512                 bmc = intf->bmc;
2513                 mutex_lock(&bmc->dyn_mutex);
2514                 kref_get(&intf->refcount);
2515         }
2516
2517         /* If we have a valid and current ID, just return that. */
2518         if (intf->in_bmc_register ||
2519             (bmc->dyn_id_set && time_is_after_jiffies(bmc->dyn_id_expiry)))
2520                 goto out_noprocessing;
2521
2522         prev_guid_set = bmc->dyn_guid_set;
2523         __get_guid(intf);
2524
2525         prev_dyn_id_set = bmc->dyn_id_set;
2526         rv = __get_device_id(intf, bmc);
2527         if (rv)
2528                 goto out;
2529
2530         /*
2531          * The guid, device id, manufacturer id, and product id should
2532          * not change on a BMC.  If it does we have to do some dancing.
2533          */
2534         if (!intf->bmc_registered
2535             || (!prev_guid_set && bmc->dyn_guid_set)
2536             || (!prev_dyn_id_set && bmc->dyn_id_set)
2537             || (prev_guid_set && bmc->dyn_guid_set
2538                 && !guid_equal(&bmc->guid, &bmc->fetch_guid))
2539             || bmc->id.device_id != bmc->fetch_id.device_id
2540             || bmc->id.manufacturer_id != bmc->fetch_id.manufacturer_id
2541             || bmc->id.product_id != bmc->fetch_id.product_id) {
2542                 struct ipmi_device_id id = bmc->fetch_id;
2543                 int guid_set = bmc->dyn_guid_set;
2544                 guid_t guid;
2545
2546                 guid = bmc->fetch_guid;
2547                 mutex_unlock(&bmc->dyn_mutex);
2548
2549                 __ipmi_bmc_unregister(intf);
2550                 /* Fill in the temporary BMC for good measure. */
2551                 intf->bmc->id = id;
2552                 intf->bmc->dyn_guid_set = guid_set;
2553                 intf->bmc->guid = guid;
2554                 if (__ipmi_bmc_register(intf, &id, guid_set, &guid, intf_num))
2555                         need_waiter(intf); /* Retry later on an error. */
2556                 else
2557                         __scan_channels(intf, &id);
2558
2559
2560                 if (!intf_set) {
2561                         /*
2562                          * We weren't given the interface on the
2563                          * command line, so restart the operation on
2564                          * the next interface for the BMC.
2565                          */
2566                         mutex_unlock(&intf->bmc_reg_mutex);
2567                         mutex_lock(&bmc->dyn_mutex);
2568                         goto retry_bmc_lock;
2569                 }
2570
2571                 /* We have a new BMC, set it up. */
2572                 bmc = intf->bmc;
2573                 mutex_lock(&bmc->dyn_mutex);
2574                 goto out_noprocessing;
2575         } else if (memcmp(&bmc->fetch_id, &bmc->id, sizeof(bmc->id)))
2576                 /* Version info changes, scan the channels again. */
2577                 __scan_channels(intf, &bmc->fetch_id);
2578
2579         bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
2580
2581 out:
2582         if (rv && prev_dyn_id_set) {
2583                 rv = 0; /* Ignore failures if we have previous data. */
2584                 bmc->dyn_id_set = prev_dyn_id_set;
2585         }
2586         if (!rv) {
2587                 bmc->id = bmc->fetch_id;
2588                 if (bmc->dyn_guid_set)
2589                         bmc->guid = bmc->fetch_guid;
2590                 else if (prev_guid_set)
2591                         /*
2592                          * The guid used to be valid and it failed to fetch,
2593                          * just use the cached value.
2594                          */
2595                         bmc->dyn_guid_set = prev_guid_set;
2596         }
2597 out_noprocessing:
2598         if (!rv) {
2599                 if (id)
2600                         *id = bmc->id;
2601
2602                 if (guid_set)
2603                         *guid_set = bmc->dyn_guid_set;
2604
2605                 if (guid && bmc->dyn_guid_set)
2606                         *guid =  bmc->guid;
2607         }
2608
2609         mutex_unlock(&bmc->dyn_mutex);
2610         mutex_unlock(&intf->bmc_reg_mutex);
2611
2612         kref_put(&intf->refcount, intf_free);
2613         return rv;
2614 }
2615
2616 static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2617                              struct ipmi_device_id *id,
2618                              bool *guid_set, guid_t *guid)
2619 {
2620         return __bmc_get_device_id(intf, bmc, id, guid_set, guid, -1);
2621 }
2622
2623 static ssize_t device_id_show(struct device *dev,
2624                               struct device_attribute *attr,
2625                               char *buf)
2626 {
2627         struct bmc_device *bmc = to_bmc_device(dev);
2628         struct ipmi_device_id id;
2629         int rv;
2630
2631         rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2632         if (rv)
2633                 return rv;
2634
2635         return snprintf(buf, 10, "%u\n", id.device_id);
2636 }
2637 static DEVICE_ATTR_RO(device_id);
2638
2639 static ssize_t provides_device_sdrs_show(struct device *dev,
2640                                          struct device_attribute *attr,
2641                                          char *buf)
2642 {
2643         struct bmc_device *bmc = to_bmc_device(dev);
2644         struct ipmi_device_id id;
2645         int rv;
2646
2647         rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2648         if (rv)
2649                 return rv;
2650
2651         return snprintf(buf, 10, "%u\n", (id.device_revision & 0x80) >> 7);
2652 }
2653 static DEVICE_ATTR_RO(provides_device_sdrs);
2654
2655 static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
2656                              char *buf)
2657 {
2658         struct bmc_device *bmc = to_bmc_device(dev);
2659         struct ipmi_device_id id;
2660         int rv;
2661
2662         rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2663         if (rv)
2664                 return rv;
2665
2666         return snprintf(buf, 20, "%u\n", id.device_revision & 0x0F);
2667 }
2668 static DEVICE_ATTR_RO(revision);
2669
2670 static ssize_t firmware_revision_show(struct device *dev,
2671                                       struct device_attribute *attr,
2672                                       char *buf)
2673 {
2674         struct bmc_device *bmc = to_bmc_device(dev);
2675         struct ipmi_device_id id;
2676         int rv;
2677
2678         rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2679         if (rv)
2680                 return rv;
2681
2682         return snprintf(buf, 20, "%u.%x\n", id.firmware_revision_1,
2683                         id.firmware_revision_2);
2684 }
2685 static DEVICE_ATTR_RO(firmware_revision);
2686
2687 static ssize_t ipmi_version_show(struct device *dev,
2688                                  struct device_attribute *attr,
2689                                  char *buf)
2690 {
2691         struct bmc_device *bmc = to_bmc_device(dev);
2692         struct ipmi_device_id id;
2693         int rv;
2694
2695         rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2696         if (rv)
2697                 return rv;
2698
2699         return snprintf(buf, 20, "%u.%u\n",
2700                         ipmi_version_major(&id),
2701                         ipmi_version_minor(&id));
2702 }
2703 static DEVICE_ATTR_RO(ipmi_version);
2704
2705 static ssize_t add_dev_support_show(struct device *dev,
2706                                     struct device_attribute *attr,
2707                                     char *buf)
2708 {
2709         struct bmc_device *bmc = to_bmc_device(dev);
2710         struct ipmi_device_id id;
2711         int rv;
2712
2713         rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2714         if (rv)
2715                 return rv;
2716
2717         return snprintf(buf, 10, "0x%02x\n", id.additional_device_support);
2718 }
2719 static DEVICE_ATTR(additional_device_support, S_IRUGO, add_dev_support_show,
2720                    NULL);
2721
2722 static ssize_t manufacturer_id_show(struct device *dev,
2723                                     struct device_attribute *attr,
2724                                     char *buf)
2725 {
2726         struct bmc_device *bmc = to_bmc_device(dev);
2727         struct ipmi_device_id id;
2728         int rv;
2729
2730         rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2731         if (rv)
2732                 return rv;
2733
2734         return snprintf(buf, 20, "0x%6.6x\n", id.manufacturer_id);
2735 }
2736 static DEVICE_ATTR_RO(manufacturer_id);
2737
2738 static ssize_t product_id_show(struct device *dev,
2739                                struct device_attribute *attr,
2740                                char *buf)
2741 {
2742         struct bmc_device *bmc = to_bmc_device(dev);
2743         struct ipmi_device_id id;
2744         int rv;
2745
2746         rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2747         if (rv)
2748                 return rv;
2749
2750         return snprintf(buf, 10, "0x%4.4x\n", id.product_id);
2751 }
2752 static DEVICE_ATTR_RO(product_id);
2753
2754 static ssize_t aux_firmware_rev_show(struct device *dev,
2755                                      struct device_attribute *attr,
2756                                      char *buf)
2757 {
2758         struct bmc_device *bmc = to_bmc_device(dev);
2759         struct ipmi_device_id id;
2760         int rv;
2761
2762         rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2763         if (rv)
2764                 return rv;
2765
2766         return snprintf(buf, 21, "0x%02x 0x%02x 0x%02x 0x%02x\n",
2767                         id.aux_firmware_revision[3],
2768                         id.aux_firmware_revision[2],
2769                         id.aux_firmware_revision[1],
2770                         id.aux_firmware_revision[0]);
2771 }
2772 static DEVICE_ATTR(aux_firmware_revision, S_IRUGO, aux_firmware_rev_show, NULL);
2773
2774 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
2775                          char *buf)
2776 {
2777         struct bmc_device *bmc = to_bmc_device(dev);
2778         bool guid_set;
2779         guid_t guid;
2780         int rv;
2781
2782         rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, &guid);
2783         if (rv)
2784                 return rv;
2785         if (!guid_set)
2786                 return -ENOENT;
2787
2788         return snprintf(buf, UUID_STRING_LEN + 1 + 1, "%pUl\n", &guid);
2789 }
2790 static DEVICE_ATTR_RO(guid);
2791
2792 static struct attribute *bmc_dev_attrs[] = {
2793         &dev_attr_device_id.attr,
2794         &dev_attr_provides_device_sdrs.attr,
2795         &dev_attr_revision.attr,
2796         &dev_attr_firmware_revision.attr,
2797         &dev_attr_ipmi_version.attr,
2798         &dev_attr_additional_device_support.attr,
2799         &dev_attr_manufacturer_id.attr,
2800         &dev_attr_product_id.attr,
2801         &dev_attr_aux_firmware_revision.attr,
2802         &dev_attr_guid.attr,
2803         NULL
2804 };
2805
2806 static umode_t bmc_dev_attr_is_visible(struct kobject *kobj,
2807                                        struct attribute *attr, int idx)
2808 {
2809         struct device *dev = kobj_to_dev(kobj);
2810         struct bmc_device *bmc = to_bmc_device(dev);
2811         umode_t mode = attr->mode;
2812         int rv;
2813
2814         if (attr == &dev_attr_aux_firmware_revision.attr) {
2815                 struct ipmi_device_id id;
2816
2817                 rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2818                 return (!rv && id.aux_firmware_revision_set) ? mode : 0;
2819         }
2820         if (attr == &dev_attr_guid.attr) {
2821                 bool guid_set;
2822
2823                 rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, NULL);
2824                 return (!rv && guid_set) ? mode : 0;
2825         }
2826         return mode;
2827 }
2828
2829 static const struct attribute_group bmc_dev_attr_group = {
2830         .attrs          = bmc_dev_attrs,
2831         .is_visible     = bmc_dev_attr_is_visible,
2832 };
2833
2834 static const struct attribute_group *bmc_dev_attr_groups[] = {
2835         &bmc_dev_attr_group,
2836         NULL
2837 };
2838
2839 static const struct device_type bmc_device_type = {
2840         .groups         = bmc_dev_attr_groups,
2841 };
2842
2843 static int __find_bmc_guid(struct device *dev, const void *data)
2844 {
2845         const guid_t *guid = data;
2846         struct bmc_device *bmc;
2847         int rv;
2848
2849         if (dev->type != &bmc_device_type)
2850                 return 0;
2851
2852         bmc = to_bmc_device(dev);
2853         rv = bmc->dyn_guid_set && guid_equal(&bmc->guid, guid);
2854         if (rv)
2855                 rv = kref_get_unless_zero(&bmc->usecount);
2856         return rv;
2857 }
2858
2859 /*
2860  * Returns with the bmc's usecount incremented, if it is non-NULL.
2861  */
2862 static struct bmc_device *ipmi_find_bmc_guid(struct device_driver *drv,
2863                                              guid_t *guid)
2864 {
2865         struct device *dev;
2866         struct bmc_device *bmc = NULL;
2867
2868         dev = driver_find_device(drv, NULL, guid, __find_bmc_guid);
2869         if (dev) {
2870                 bmc = to_bmc_device(dev);
2871                 put_device(dev);
2872         }
2873         return bmc;
2874 }
2875
2876 struct prod_dev_id {
2877         unsigned int  product_id;
2878         unsigned char device_id;
2879 };
2880
2881 static int __find_bmc_prod_dev_id(struct device *dev, const void *data)
2882 {
2883         const struct prod_dev_id *cid = data;
2884         struct bmc_device *bmc;
2885         int rv;
2886
2887         if (dev->type != &bmc_device_type)
2888                 return 0;
2889
2890         bmc = to_bmc_device(dev);
2891         rv = (bmc->id.product_id == cid->product_id
2892               && bmc->id.device_id == cid->device_id);
2893         if (rv)
2894                 rv = kref_get_unless_zero(&bmc->usecount);
2895         return rv;
2896 }
2897
2898 /*
2899  * Returns with the bmc's usecount incremented, if it is non-NULL.
2900  */
2901 static struct bmc_device *ipmi_find_bmc_prod_dev_id(
2902         struct device_driver *drv,
2903         unsigned int product_id, unsigned char device_id)
2904 {
2905         struct prod_dev_id id = {
2906                 .product_id = product_id,
2907                 .device_id = device_id,
2908         };
2909         struct device *dev;
2910         struct bmc_device *bmc = NULL;
2911
2912         dev = driver_find_device(drv, NULL, &id, __find_bmc_prod_dev_id);
2913         if (dev) {
2914                 bmc = to_bmc_device(dev);
2915                 put_device(dev);
2916         }
2917         return bmc;
2918 }
2919
2920 static DEFINE_IDA(ipmi_bmc_ida);
2921
2922 static void
2923 release_bmc_device(struct device *dev)
2924 {
2925         kfree(to_bmc_device(dev));
2926 }
2927
2928 static void cleanup_bmc_work(struct work_struct *work)
2929 {
2930         struct bmc_device *bmc = container_of(work, struct bmc_device,
2931                                               remove_work);
2932         int id = bmc->pdev.id; /* Unregister overwrites id */
2933
2934         platform_device_unregister(&bmc->pdev);
2935         ida_simple_remove(&ipmi_bmc_ida, id);
2936 }
2937
2938 static void
2939 cleanup_bmc_device(struct kref *ref)
2940 {
2941         struct bmc_device *bmc = container_of(ref, struct bmc_device, usecount);
2942
2943         /*
2944          * Remove the platform device in a work queue to avoid issues
2945          * with removing the device attributes while reading a device
2946          * attribute.
2947          */
2948         queue_work(remove_work_wq, &bmc->remove_work);
2949 }
2950
2951 /*
2952  * Must be called with intf->bmc_reg_mutex held.
2953  */
2954 static void __ipmi_bmc_unregister(struct ipmi_smi *intf)
2955 {
2956         struct bmc_device *bmc = intf->bmc;
2957
2958         if (!intf->bmc_registered)
2959                 return;
2960
2961         sysfs_remove_link(&intf->si_dev->kobj, "bmc");
2962         sysfs_remove_link(&bmc->pdev.dev.kobj, intf->my_dev_name);
2963         kfree(intf->my_dev_name);
2964         intf->my_dev_name = NULL;
2965
2966         mutex_lock(&bmc->dyn_mutex);
2967         list_del(&intf->bmc_link);
2968         mutex_unlock(&bmc->dyn_mutex);
2969         intf->bmc = &intf->tmp_bmc;
2970         kref_put(&bmc->usecount, cleanup_bmc_device);
2971         intf->bmc_registered = false;
2972 }
2973
2974 static void ipmi_bmc_unregister(struct ipmi_smi *intf)
2975 {
2976         mutex_lock(&intf->bmc_reg_mutex);
2977         __ipmi_bmc_unregister(intf);
2978         mutex_unlock(&intf->bmc_reg_mutex);
2979 }
2980
2981 /*
2982  * Must be called with intf->bmc_reg_mutex held.
2983  */
2984 static int __ipmi_bmc_register(struct ipmi_smi *intf,
2985                                struct ipmi_device_id *id,
2986                                bool guid_set, guid_t *guid, int intf_num)
2987 {
2988         int               rv;
2989         struct bmc_device *bmc;
2990         struct bmc_device *old_bmc;
2991
2992         /*
2993          * platform_device_register() can cause bmc_reg_mutex to
2994          * be claimed because of the is_visible functions of
2995          * the attributes.  Eliminate possible recursion and
2996          * release the lock.
2997          */
2998         intf->in_bmc_register = true;
2999         mutex_unlock(&intf->bmc_reg_mutex);
3000
3001         /*
3002          * Try to find if there is an bmc_device struct
3003          * representing the interfaced BMC already
3004          */
3005         mutex_lock(&ipmidriver_mutex);
3006         if (guid_set)
3007                 old_bmc = ipmi_find_bmc_guid(&ipmidriver.driver, guid);
3008         else
3009                 old_bmc = ipmi_find_bmc_prod_dev_id(&ipmidriver.driver,
3010                                                     id->product_id,
3011                                                     id->device_id);
3012
3013         /*
3014          * If there is already an bmc_device, free the new one,
3015          * otherwise register the new BMC device
3016          */
3017         if (old_bmc) {
3018                 bmc = old_bmc;
3019                 /*
3020                  * Note: old_bmc already has usecount incremented by
3021                  * the BMC find functions.
3022                  */
3023                 intf->bmc = old_bmc;
3024                 mutex_lock(&bmc->dyn_mutex);
3025                 list_add_tail(&intf->bmc_link, &bmc->intfs);
3026                 mutex_unlock(&bmc->dyn_mutex);
3027
3028                 dev_info(intf->si_dev,
3029                          "interfacing existing BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3030                          bmc->id.manufacturer_id,
3031                          bmc->id.product_id,
3032                          bmc->id.device_id);
3033         } else {
3034                 bmc = kzalloc(sizeof(*bmc), GFP_KERNEL);
3035                 if (!bmc) {
3036                         rv = -ENOMEM;
3037                         goto out;
3038                 }
3039                 INIT_LIST_HEAD(&bmc->intfs);
3040                 mutex_init(&bmc->dyn_mutex);
3041                 INIT_WORK(&bmc->remove_work, cleanup_bmc_work);
3042
3043                 bmc->id = *id;
3044                 bmc->dyn_id_set = 1;
3045                 bmc->dyn_guid_set = guid_set;
3046                 bmc->guid = *guid;
3047                 bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
3048
3049                 bmc->pdev.name = "ipmi_bmc";
3050
3051                 rv = ida_simple_get(&ipmi_bmc_ida, 0, 0, GFP_KERNEL);
3052                 if (rv < 0) {
3053                         kfree(bmc);
3054                         goto out;
3055                 }
3056
3057                 bmc->pdev.dev.driver = &ipmidriver.driver;
3058                 bmc->pdev.id = rv;
3059                 bmc->pdev.dev.release = release_bmc_device;
3060                 bmc->pdev.dev.type = &bmc_device_type;
3061                 kref_init(&bmc->usecount);
3062
3063                 intf->bmc = bmc;
3064                 mutex_lock(&bmc->dyn_mutex);
3065                 list_add_tail(&intf->bmc_link, &bmc->intfs);
3066                 mutex_unlock(&bmc->dyn_mutex);
3067
3068                 rv = platform_device_register(&bmc->pdev);
3069                 if (rv) {
3070                         dev_err(intf->si_dev,
3071                                 "Unable to register bmc device: %d\n",
3072                                 rv);
3073                         goto out_list_del;
3074                 }
3075
3076                 dev_info(intf->si_dev,
3077                          "Found new BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3078                          bmc->id.manufacturer_id,
3079                          bmc->id.product_id,
3080                          bmc->id.device_id);
3081         }
3082
3083         /*
3084          * create symlink from system interface device to bmc device
3085          * and back.
3086          */
3087         rv = sysfs_create_link(&intf->si_dev->kobj, &bmc->pdev.dev.kobj, "bmc");
3088         if (rv) {
3089                 dev_err(intf->si_dev, "Unable to create bmc symlink: %d\n", rv);
3090                 goto out_put_bmc;
3091         }
3092
3093         if (intf_num == -1)
3094                 intf_num = intf->intf_num;
3095         intf->my_dev_name = kasprintf(GFP_KERNEL, "ipmi%d", intf_num);
3096         if (!intf->my_dev_name) {
3097                 rv = -ENOMEM;
3098                 dev_err(intf->si_dev, "Unable to allocate link from BMC: %d\n",
3099                         rv);
3100                 goto out_unlink1;
3101         }
3102
3103         rv = sysfs_create_link(&bmc->pdev.dev.kobj, &intf->si_dev->kobj,
3104                                intf->my_dev_name);
3105         if (rv) {
3106                 dev_err(intf->si_dev, "Unable to create symlink to bmc: %d\n",
3107                         rv);
3108                 goto out_free_my_dev_name;
3109         }
3110
3111         intf->bmc_registered = true;
3112
3113 out:
3114         mutex_unlock(&ipmidriver_mutex);
3115         mutex_lock(&intf->bmc_reg_mutex);
3116         intf->in_bmc_register = false;
3117         return rv;
3118
3119
3120 out_free_my_dev_name:
3121         kfree(intf->my_dev_name);
3122         intf->my_dev_name = NULL;
3123
3124 out_unlink1:
3125         sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3126
3127 out_put_bmc:
3128         mutex_lock(&bmc->dyn_mutex);
3129         list_del(&intf->bmc_link);
3130         mutex_unlock(&bmc->dyn_mutex);
3131         intf->bmc = &intf->tmp_bmc;
3132         kref_put(&bmc->usecount, cleanup_bmc_device);
3133         goto out;
3134
3135 out_list_del:
3136         mutex_lock(&bmc->dyn_mutex);
3137         list_del(&intf->bmc_link);
3138         mutex_unlock(&bmc->dyn_mutex);
3139         intf->bmc = &intf->tmp_bmc;
3140         put_device(&bmc->pdev.dev);
3141         goto out;
3142 }
3143
3144 static int
3145 send_guid_cmd(struct ipmi_smi *intf, int chan)
3146 {
3147         struct kernel_ipmi_msg            msg;
3148         struct ipmi_system_interface_addr si;
3149
3150         si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3151         si.channel = IPMI_BMC_CHANNEL;
3152         si.lun = 0;
3153
3154         msg.netfn = IPMI_NETFN_APP_REQUEST;
3155         msg.cmd = IPMI_GET_DEVICE_GUID_CMD;
3156         msg.data = NULL;
3157         msg.data_len = 0;
3158         return i_ipmi_request(NULL,
3159                               intf,
3160                               (struct ipmi_addr *) &si,
3161                               0,
3162                               &msg,
3163                               intf,
3164                               NULL,
3165                               NULL,
3166                               0,
3167                               intf->addrinfo[0].address,
3168                               intf->addrinfo[0].lun,
3169                               -1, 0);
3170 }
3171
3172 static void guid_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3173 {
3174         struct bmc_device *bmc = intf->bmc;
3175
3176         if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3177             || (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
3178             || (msg->msg.cmd != IPMI_GET_DEVICE_GUID_CMD))
3179                 /* Not for me */
3180                 return;
3181
3182         if (msg->msg.data[0] != 0) {
3183                 /* Error from getting the GUID, the BMC doesn't have one. */
3184                 bmc->dyn_guid_set = 0;
3185                 goto out;
3186         }
3187
3188         if (msg->msg.data_len < UUID_SIZE + 1) {
3189                 bmc->dyn_guid_set = 0;
3190                 dev_warn(intf->si_dev,
3191                          "The GUID response from the BMC was too short, it was %d but should have been %d.  Assuming GUID is not available.\n",
3192                          msg->msg.data_len, UUID_SIZE + 1);
3193                 goto out;
3194         }
3195
3196         import_guid(&bmc->fetch_guid, msg->msg.data + 1);
3197         /*
3198          * Make sure the guid data is available before setting
3199          * dyn_guid_set.
3200          */
3201         smp_wmb();
3202         bmc->dyn_guid_set = 1;
3203  out:
3204         wake_up(&intf->waitq);
3205 }
3206
3207 static void __get_guid(struct ipmi_smi *intf)
3208 {
3209         int rv;
3210         struct bmc_device *bmc = intf->bmc;
3211
3212         bmc->dyn_guid_set = 2;
3213         intf->null_user_handler = guid_handler;
3214         rv = send_guid_cmd(intf, 0);
3215         if (rv)
3216                 /* Send failed, no GUID available. */
3217                 bmc->dyn_guid_set = 0;
3218         else
3219                 wait_event(intf->waitq, bmc->dyn_guid_set != 2);
3220
3221         /* dyn_guid_set makes the guid data available. */
3222         smp_rmb();
3223
3224         intf->null_user_handler = NULL;
3225 }
3226
3227 static int
3228 send_channel_info_cmd(struct ipmi_smi *intf, int chan)
3229 {
3230         struct kernel_ipmi_msg            msg;
3231         unsigned char                     data[1];
3232         struct ipmi_system_interface_addr si;
3233
3234         si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3235         si.channel = IPMI_BMC_CHANNEL;
3236         si.lun = 0;
3237
3238         msg.netfn = IPMI_NETFN_APP_REQUEST;
3239         msg.cmd = IPMI_GET_CHANNEL_INFO_CMD;
3240         msg.data = data;
3241         msg.data_len = 1;
3242         data[0] = chan;
3243         return i_ipmi_request(NULL,
3244                               intf,
3245                               (struct ipmi_addr *) &si,
3246                               0,
3247                               &msg,
3248                               intf,
3249                               NULL,
3250                               NULL,
3251                               0,
3252                               intf->addrinfo[0].address,
3253                               intf->addrinfo[0].lun,
3254                               -1, 0);
3255 }
3256
3257 static void
3258 channel_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3259 {
3260         int rv = 0;
3261         int ch;
3262         unsigned int set = intf->curr_working_cset;
3263         struct ipmi_channel *chans;
3264
3265         if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3266             && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
3267             && (msg->msg.cmd == IPMI_GET_CHANNEL_INFO_CMD)) {
3268                 /* It's the one we want */
3269                 if (msg->msg.data[0] != 0) {
3270                         /* Got an error from the channel, just go on. */
3271                         if (msg->msg.data[0] == IPMI_INVALID_COMMAND_ERR) {
3272                                 /*
3273                                  * If the MC does not support this
3274                                  * command, that is legal.  We just
3275                                  * assume it has one IPMB at channel
3276                                  * zero.
3277                                  */
3278                                 intf->wchannels[set].c[0].medium
3279                                         = IPMI_CHANNEL_MEDIUM_IPMB;
3280                                 intf->wchannels[set].c[0].protocol
3281                                         = IPMI_CHANNEL_PROTOCOL_IPMB;
3282
3283                                 intf->channel_list = intf->wchannels + set;
3284                                 intf->channels_ready = true;
3285                                 wake_up(&intf->waitq);
3286                                 goto out;
3287                         }
3288                         goto next_channel;
3289                 }
3290                 if (msg->msg.data_len < 4) {
3291                         /* Message not big enough, just go on. */
3292                         goto next_channel;
3293                 }
3294                 ch = intf->curr_channel;
3295                 chans = intf->wchannels[set].c;
3296                 chans[ch].medium = msg->msg.data[2] & 0x7f;
3297                 chans[ch].protocol = msg->msg.data[3] & 0x1f;
3298
3299  next_channel:
3300                 intf->curr_channel++;
3301                 if (intf->curr_channel >= IPMI_MAX_CHANNELS) {
3302                         intf->channel_list = intf->wchannels + set;
3303                         intf->channels_ready = true;
3304                         wake_up(&intf->waitq);
3305                 } else {
3306                         intf->channel_list = intf->wchannels + set;
3307                         intf->channels_ready = true;
3308                         rv = send_channel_info_cmd(intf, intf->curr_channel);
3309                 }
3310
3311                 if (rv) {
3312                         /* Got an error somehow, just give up. */
3313                         dev_warn(intf->si_dev,
3314                                  "Error sending channel information for channel %d: %d\n",
3315                                  intf->curr_channel, rv);
3316
3317                         intf->channel_list = intf->wchannels + set;
3318                         intf->channels_ready = true;
3319                         wake_up(&intf->waitq);
3320                 }
3321         }
3322  out:
3323         return;
3324 }
3325
3326 /*
3327  * Must be holding intf->bmc_reg_mutex to call this.
3328  */
3329 static int __scan_channels(struct ipmi_smi *intf, struct ipmi_device_id *id)
3330 {
3331         int rv;
3332
3333         if (ipmi_version_major(id) > 1
3334                         || (ipmi_version_major(id) == 1
3335                             && ipmi_version_minor(id) >= 5)) {
3336                 unsigned int set;
3337
3338                 /*
3339                  * Start scanning the channels to see what is
3340                  * available.
3341                  */
3342                 set = !intf->curr_working_cset;
3343                 intf->curr_working_cset = set;
3344                 memset(&intf->wchannels[set], 0,
3345                        sizeof(struct ipmi_channel_set));
3346
3347                 intf->null_user_handler = channel_handler;
3348                 intf->curr_channel = 0;
3349                 rv = send_channel_info_cmd(intf, 0);
3350                 if (rv) {
3351                         dev_warn(intf->si_dev,
3352                                  "Error sending channel information for channel 0, %d\n",
3353                                  rv);
3354                         intf->null_user_handler = NULL;
3355                         return -EIO;
3356                 }
3357
3358                 /* Wait for the channel info to be read. */
3359                 wait_event(intf->waitq, intf->channels_ready);
3360                 intf->null_user_handler = NULL;
3361         } else {
3362                 unsigned int set = intf->curr_working_cset;
3363
3364                 /* Assume a single IPMB channel at zero. */
3365                 intf->wchannels[set].c[0].medium = IPMI_CHANNEL_MEDIUM_IPMB;
3366                 intf->wchannels[set].c[0].protocol = IPMI_CHANNEL_PROTOCOL_IPMB;
3367                 intf->channel_list = intf->wchannels + set;
3368                 intf->channels_ready = true;
3369         }
3370
3371         return 0;
3372 }
3373
3374 static void ipmi_poll(struct ipmi_smi *intf)
3375 {
3376         if (intf->handlers->poll)
3377                 intf->handlers->poll(intf->send_info);
3378         /* In case something came in */
3379         handle_new_recv_msgs(intf);
3380 }
3381
3382 void ipmi_poll_interface(struct ipmi_user *user)
3383 {
3384         ipmi_poll(user->intf);
3385 }
3386 EXPORT_SYMBOL(ipmi_poll_interface);
3387
3388 static void redo_bmc_reg(struct work_struct *work)
3389 {
3390         struct ipmi_smi *intf = container_of(work, struct ipmi_smi,
3391                                              bmc_reg_work);
3392
3393         if (!intf->in_shutdown)
3394                 bmc_get_device_id(intf, NULL, NULL, NULL, NULL);
3395
3396         kref_put(&intf->refcount, intf_free);
3397 }
3398
3399 int ipmi_add_smi(struct module         *owner,
3400                  const struct ipmi_smi_handlers *handlers,
3401                  void                  *send_info,
3402                  struct device         *si_dev,
3403                  unsigned char         slave_addr)
3404 {
3405         int              i, j;
3406         int              rv;
3407         struct ipmi_smi *intf, *tintf;
3408         struct list_head *link;
3409         struct ipmi_device_id id;
3410
3411         /*
3412          * Make sure the driver is actually initialized, this handles
3413          * problems with initialization order.
3414          */
3415         rv = ipmi_init_msghandler();
3416         if (rv)
3417                 return rv;
3418
3419         intf = kzalloc(sizeof(*intf), GFP_KERNEL);
3420         if (!intf)
3421                 return -ENOMEM;
3422
3423         rv = init_srcu_struct(&intf->users_srcu);
3424         if (rv) {
3425                 kfree(intf);
3426                 return rv;
3427         }
3428
3429         intf->owner = owner;
3430         intf->bmc = &intf->tmp_bmc;
3431         INIT_LIST_HEAD(&intf->bmc->intfs);
3432         mutex_init(&intf->bmc->dyn_mutex);
3433         INIT_LIST_HEAD(&intf->bmc_link);
3434         mutex_init(&intf->bmc_reg_mutex);
3435         intf->intf_num = -1; /* Mark it invalid for now. */
3436         kref_init(&intf->refcount);
3437         INIT_WORK(&intf->bmc_reg_work, redo_bmc_reg);
3438         intf->si_dev = si_dev;
3439         for (j = 0; j < IPMI_MAX_CHANNELS; j++) {
3440                 intf->addrinfo[j].address = IPMI_BMC_SLAVE_ADDR;
3441                 intf->addrinfo[j].lun = 2;
3442         }
3443         if (slave_addr != 0)
3444                 intf->addrinfo[0].address = slave_addr;
3445         INIT_LIST_HEAD(&intf->users);
3446         intf->handlers = handlers;
3447         intf->send_info = send_info;
3448         spin_lock_init(&intf->seq_lock);
3449         for (j = 0; j < IPMI_IPMB_NUM_SEQ; j++) {
3450                 intf->seq_table[j].inuse = 0;
3451                 intf->seq_table[j].seqid = 0;
3452         }
3453         intf->curr_seq = 0;
3454         spin_lock_init(&intf->waiting_rcv_msgs_lock);
3455         INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
3456         tasklet_setup(&intf->recv_tasklet,
3457                      smi_recv_tasklet);
3458         atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
3459         spin_lock_init(&intf->xmit_msgs_lock);
3460         INIT_LIST_HEAD(&intf->xmit_msgs);
3461         INIT_LIST_HEAD(&intf->hp_xmit_msgs);
3462         spin_lock_init(&intf->events_lock);
3463         spin_lock_init(&intf->watch_lock);
3464         atomic_set(&intf->event_waiters, 0);
3465         intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
3466         INIT_LIST_HEAD(&intf->waiting_events);
3467         intf->waiting_events_count = 0;
3468         mutex_init(&intf->cmd_rcvrs_mutex);
3469         spin_lock_init(&intf->maintenance_mode_lock);
3470         INIT_LIST_HEAD(&intf->cmd_rcvrs);
3471         init_waitqueue_head(&intf->waitq);
3472         for (i = 0; i < IPMI_NUM_STATS; i++)
3473                 atomic_set(&intf->stats[i], 0);
3474
3475         mutex_lock(&ipmi_interfaces_mutex);
3476         /* Look for a hole in the numbers. */
3477         i = 0;
3478         link = &ipmi_interfaces;
3479         list_for_each_entry_rcu(tintf, &ipmi_interfaces, link,
3480                                 ipmi_interfaces_mutex_held()) {
3481                 if (tintf->intf_num != i) {
3482                         link = &tintf->link;
3483                         break;
3484                 }
3485                 i++;
3486         }
3487         /* Add the new interface in numeric order. */
3488         if (i == 0)
3489                 list_add_rcu(&intf->link, &ipmi_interfaces);
3490         else
3491                 list_add_tail_rcu(&intf->link, link);
3492
3493         rv = handlers->start_processing(send_info, intf);
3494         if (rv)
3495                 goto out_err;
3496
3497         rv = __bmc_get_device_id(intf, NULL, &id, NULL, NULL, i);
3498         if (rv) {
3499                 dev_err(si_dev, "Unable to get the device id: %d\n", rv);
3500                 goto out_err_started;
3501         }
3502
3503         mutex_lock(&intf->bmc_reg_mutex);
3504         rv = __scan_channels(intf, &id);
3505         mutex_unlock(&intf->bmc_reg_mutex);
3506         if (rv)
3507                 goto out_err_bmc_reg;
3508
3509         /*
3510          * Keep memory order straight for RCU readers.  Make
3511          * sure everything else is committed to memory before
3512          * setting intf_num to mark the interface valid.
3513          */
3514         smp_wmb();
3515         intf->intf_num = i;
3516         mutex_unlock(&ipmi_interfaces_mutex);
3517
3518         /* After this point the interface is legal to use. */
3519         call_smi_watchers(i, intf->si_dev);
3520
3521         return 0;
3522
3523  out_err_bmc_reg:
3524         ipmi_bmc_unregister(intf);
3525  out_err_started:
3526         if (intf->handlers->shutdown)
3527                 intf->handlers->shutdown(intf->send_info);
3528  out_err:
3529         list_del_rcu(&intf->link);
3530         mutex_unlock(&ipmi_interfaces_mutex);
3531         synchronize_srcu(&ipmi_interfaces_srcu);
3532         cleanup_srcu_struct(&intf->users_srcu);
3533         kref_put(&intf->refcount, intf_free);
3534
3535         return rv;
3536 }
3537 EXPORT_SYMBOL(ipmi_add_smi);
3538
3539 static void deliver_smi_err_response(struct ipmi_smi *intf,
3540                                      struct ipmi_smi_msg *msg,
3541                                      unsigned char err)
3542 {
3543         msg->rsp[0] = msg->data[0] | 4;
3544         msg->rsp[1] = msg->data[1];
3545         msg->rsp[2] = err;
3546         msg->rsp_size = 3;
3547         /* It's an error, so it will never requeue, no need to check return. */
3548         handle_one_recv_msg(intf, msg);
3549 }
3550
3551 static void cleanup_smi_msgs(struct ipmi_smi *intf)
3552 {
3553         int              i;
3554         struct seq_table *ent;
3555         struct ipmi_smi_msg *msg;
3556         struct list_head *entry;
3557         struct list_head tmplist;
3558
3559         /* Clear out our transmit queues and hold the messages. */
3560         INIT_LIST_HEAD(&tmplist);
3561         list_splice_tail(&intf->hp_xmit_msgs, &tmplist);
3562         list_splice_tail(&intf->xmit_msgs, &tmplist);
3563
3564         /* Current message first, to preserve order */
3565         while (intf->curr_msg && !list_empty(&intf->waiting_rcv_msgs)) {
3566                 /* Wait for the message to clear out. */
3567                 schedule_timeout(1);
3568         }
3569
3570         /* No need for locks, the interface is down. */
3571
3572         /*
3573          * Return errors for all pending messages in queue and in the
3574          * tables waiting for remote responses.
3575          */
3576         while (!list_empty(&tmplist)) {
3577                 entry = tmplist.next;
3578                 list_del(entry);
3579                 msg = list_entry(entry, struct ipmi_smi_msg, link);
3580                 deliver_smi_err_response(intf, msg, IPMI_ERR_UNSPECIFIED);
3581         }
3582
3583         for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
3584                 ent = &intf->seq_table[i];
3585                 if (!ent->inuse)
3586                         continue;
3587                 deliver_err_response(intf, ent->recv_msg, IPMI_ERR_UNSPECIFIED);
3588         }
3589 }
3590
3591 void ipmi_unregister_smi(struct ipmi_smi *intf)
3592 {
3593         struct ipmi_smi_watcher *w;
3594         int intf_num = intf->intf_num, index;
3595
3596         mutex_lock(&ipmi_interfaces_mutex);
3597         intf->intf_num = -1;
3598         intf->in_shutdown = true;
3599         list_del_rcu(&intf->link);
3600         mutex_unlock(&ipmi_interfaces_mutex);
3601         synchronize_srcu(&ipmi_interfaces_srcu);
3602
3603         /* At this point no users can be added to the interface. */
3604
3605         /*
3606          * Call all the watcher interfaces to tell them that
3607          * an interface is going away.
3608          */
3609         mutex_lock(&smi_watchers_mutex);
3610         list_for_each_entry(w, &smi_watchers, link)
3611                 w->smi_gone(intf_num);
3612         mutex_unlock(&smi_watchers_mutex);
3613
3614         index = srcu_read_lock(&intf->users_srcu);
3615         while (!list_empty(&intf->users)) {
3616                 struct ipmi_user *user =
3617                         container_of(list_next_rcu(&intf->users),
3618                                      struct ipmi_user, link);
3619
3620                 _ipmi_destroy_user(user);
3621         }
3622         srcu_read_unlock(&intf->users_srcu, index);
3623
3624         if (intf->handlers->shutdown)
3625                 intf->handlers->shutdown(intf->send_info);
3626
3627         cleanup_smi_msgs(intf);
3628
3629         ipmi_bmc_unregister(intf);
3630
3631         cleanup_srcu_struct(&intf->users_srcu);
3632         kref_put(&intf->refcount, intf_free);
3633 }
3634 EXPORT_SYMBOL(ipmi_unregister_smi);
3635
3636 static int handle_ipmb_get_msg_rsp(struct ipmi_smi *intf,
3637                                    struct ipmi_smi_msg *msg)
3638 {
3639         struct ipmi_ipmb_addr ipmb_addr;
3640         struct ipmi_recv_msg  *recv_msg;
3641
3642         /*
3643          * This is 11, not 10, because the response must contain a
3644          * completion code.
3645          */
3646         if (msg->rsp_size < 11) {
3647                 /* Message not big enough, just ignore it. */
3648                 ipmi_inc_stat(intf, invalid_ipmb_responses);
3649                 return 0;
3650         }
3651
3652         if (msg->rsp[2] != 0) {
3653                 /* An error getting the response, just ignore it. */
3654                 return 0;
3655         }
3656
3657         ipmb_addr.addr_type = IPMI_IPMB_ADDR_TYPE;
3658         ipmb_addr.slave_addr = msg->rsp[6];
3659         ipmb_addr.channel = msg->rsp[3] & 0x0f;
3660         ipmb_addr.lun = msg->rsp[7] & 3;
3661
3662         /*
3663          * It's a response from a remote entity.  Look up the sequence
3664          * number and handle the response.
3665          */
3666         if (intf_find_seq(intf,
3667                           msg->rsp[7] >> 2,
3668                           msg->rsp[3] & 0x0f,
3669                           msg->rsp[8],
3670                           (msg->rsp[4] >> 2) & (~1),
3671                           (struct ipmi_addr *) &ipmb_addr,
3672                           &recv_msg)) {
3673                 /*
3674                  * We were unable to find the sequence number,
3675                  * so just nuke the message.
3676                  */
3677                 ipmi_inc_stat(intf, unhandled_ipmb_responses);
3678                 return 0;
3679         }
3680
3681         memcpy(recv_msg->msg_data, &msg->rsp[9], msg->rsp_size - 9);
3682         /*
3683          * The other fields matched, so no need to set them, except
3684          * for netfn, which needs to be the response that was
3685          * returned, not the request value.
3686          */
3687         recv_msg->msg.netfn = msg->rsp[4] >> 2;
3688         recv_msg->msg.data = recv_msg->msg_data;
3689         recv_msg->msg.data_len = msg->rsp_size - 10;
3690         recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3691         if (deliver_response(intf, recv_msg))
3692                 ipmi_inc_stat(intf, unhandled_ipmb_responses);
3693         else
3694                 ipmi_inc_stat(intf, handled_ipmb_responses);
3695
3696         return 0;
3697 }
3698
3699 static int handle_ipmb_get_msg_cmd(struct ipmi_smi *intf,
3700                                    struct ipmi_smi_msg *msg)
3701 {
3702         struct cmd_rcvr          *rcvr;
3703         int                      rv = 0;
3704         unsigned char            netfn;
3705         unsigned char            cmd;
3706         unsigned char            chan;
3707         struct ipmi_user         *user = NULL;
3708         struct ipmi_ipmb_addr    *ipmb_addr;
3709         struct ipmi_recv_msg     *recv_msg;
3710
3711         if (msg->rsp_size < 10) {
3712                 /* Message not big enough, just ignore it. */
3713                 ipmi_inc_stat(intf, invalid_commands);
3714                 return 0;
3715         }
3716
3717         if (msg->rsp[2] != 0) {
3718                 /* An error getting the response, just ignore it. */
3719                 return 0;
3720         }
3721
3722         netfn = msg->rsp[4] >> 2;
3723         cmd = msg->rsp[8];
3724         chan = msg->rsp[3] & 0xf;
3725
3726         rcu_read_lock();
3727         rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3728         if (rcvr) {
3729                 user = rcvr->user;
3730                 kref_get(&user->refcount);
3731         } else
3732                 user = NULL;
3733         rcu_read_unlock();
3734
3735         if (user == NULL) {
3736                 /* We didn't find a user, deliver an error response. */
3737                 ipmi_inc_stat(intf, unhandled_commands);
3738
3739                 msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
3740                 msg->data[1] = IPMI_SEND_MSG_CMD;
3741                 msg->data[2] = msg->rsp[3];
3742                 msg->data[3] = msg->rsp[6];
3743                 msg->data[4] = ((netfn + 1) << 2) | (msg->rsp[7] & 0x3);
3744                 msg->data[5] = ipmb_checksum(&msg->data[3], 2);
3745                 msg->data[6] = intf->addrinfo[msg->rsp[3] & 0xf].address;
3746                 /* rqseq/lun */
3747                 msg->data[7] = (msg->rsp[7] & 0xfc) | (msg->rsp[4] & 0x3);
3748                 msg->data[8] = msg->rsp[8]; /* cmd */
3749                 msg->data[9] = IPMI_INVALID_CMD_COMPLETION_CODE;
3750                 msg->data[10] = ipmb_checksum(&msg->data[6], 4);
3751                 msg->data_size = 11;
3752
3753                 pr_debug("Invalid command: %*ph\n", msg->data_size, msg->data);
3754
3755                 rcu_read_lock();
3756                 if (!intf->in_shutdown) {
3757                         smi_send(intf, intf->handlers, msg, 0);
3758                         /*
3759                          * We used the message, so return the value
3760                          * that causes it to not be freed or
3761                          * queued.
3762                          */
3763                         rv = -1;
3764                 }
3765                 rcu_read_unlock();
3766         } else {
3767                 recv_msg = ipmi_alloc_recv_msg();
3768                 if (!recv_msg) {
3769                         /*
3770                          * We couldn't allocate memory for the
3771                          * message, so requeue it for handling
3772                          * later.
3773                          */
3774                         rv = 1;
3775                         kref_put(&user->refcount, free_user);
3776                 } else {
3777                         /* Extract the source address from the data. */
3778                         ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr;
3779                         ipmb_addr->addr_type = IPMI_IPMB_ADDR_TYPE;
3780                         ipmb_addr->slave_addr = msg->rsp[6];
3781                         ipmb_addr->lun = msg->rsp[7] & 3;
3782                         ipmb_addr->channel = msg->rsp[3] & 0xf;
3783
3784                         /*
3785                          * Extract the rest of the message information
3786                          * from the IPMB header.
3787                          */
3788                         recv_msg->user = user;
3789                         recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3790                         recv_msg->msgid = msg->rsp[7] >> 2;
3791                         recv_msg->msg.netfn = msg->rsp[4] >> 2;
3792                         recv_msg->msg.cmd = msg->rsp[8];
3793                         recv_msg->msg.data = recv_msg->msg_data;
3794
3795                         /*
3796                          * We chop off 10, not 9 bytes because the checksum
3797                          * at the end also needs to be removed.
3798                          */
3799                         recv_msg->msg.data_len = msg->rsp_size - 10;
3800                         memcpy(recv_msg->msg_data, &msg->rsp[9],
3801                                msg->rsp_size - 10);
3802                         if (deliver_response(intf, recv_msg))
3803                                 ipmi_inc_stat(intf, unhandled_commands);
3804                         else
3805                                 ipmi_inc_stat(intf, handled_commands);
3806                 }
3807         }
3808
3809         return rv;
3810 }
3811
3812 static int handle_lan_get_msg_rsp(struct ipmi_smi *intf,
3813                                   struct ipmi_smi_msg *msg)
3814 {
3815         struct ipmi_lan_addr  lan_addr;
3816         struct ipmi_recv_msg  *recv_msg;
3817
3818
3819         /*
3820          * This is 13, not 12, because the response must contain a
3821          * completion code.
3822          */
3823         if (msg->rsp_size < 13) {
3824                 /* Message not big enough, just ignore it. */
3825                 ipmi_inc_stat(intf, invalid_lan_responses);
3826                 return 0;
3827         }
3828
3829         if (msg->rsp[2] != 0) {
3830                 /* An error getting the response, just ignore it. */
3831                 return 0;
3832         }
3833
3834         lan_addr.addr_type = IPMI_LAN_ADDR_TYPE;
3835         lan_addr.session_handle = msg->rsp[4];
3836         lan_addr.remote_SWID = msg->rsp[8];
3837         lan_addr.local_SWID = msg->rsp[5];
3838         lan_addr.channel = msg->rsp[3] & 0x0f;
3839         lan_addr.privilege = msg->rsp[3] >> 4;
3840         lan_addr.lun = msg->rsp[9] & 3;
3841
3842         /*
3843          * It's a response from a remote entity.  Look up the sequence
3844          * number and handle the response.
3845          */
3846         if (intf_find_seq(intf,
3847                           msg->rsp[9] >> 2,
3848                           msg->rsp[3] & 0x0f,
3849                           msg->rsp[10],
3850                           (msg->rsp[6] >> 2) & (~1),
3851                           (struct ipmi_addr *) &lan_addr,
3852                           &recv_msg)) {
3853                 /*
3854                  * We were unable to find the sequence number,
3855                  * so just nuke the message.
3856                  */
3857                 ipmi_inc_stat(intf, unhandled_lan_responses);
3858                 return 0;
3859         }
3860
3861         memcpy(recv_msg->msg_data, &msg->rsp[11], msg->rsp_size - 11);
3862         /*
3863          * The other fields matched, so no need to set them, except
3864          * for netfn, which needs to be the response that was
3865          * returned, not the request value.
3866          */
3867         recv_msg->msg.netfn = msg->rsp[6] >> 2;
3868         recv_msg->msg.data = recv_msg->msg_data;
3869         recv_msg->msg.data_len = msg->rsp_size - 12;
3870         recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3871         if (deliver_response(intf, recv_msg))
3872                 ipmi_inc_stat(intf, unhandled_lan_responses);
3873         else
3874                 ipmi_inc_stat(intf, handled_lan_responses);
3875
3876         return 0;
3877 }
3878
3879 static int handle_lan_get_msg_cmd(struct ipmi_smi *intf,
3880                                   struct ipmi_smi_msg *msg)
3881 {
3882         struct cmd_rcvr          *rcvr;
3883         int                      rv = 0;
3884         unsigned char            netfn;
3885         unsigned char            cmd;
3886         unsigned char            chan;
3887         struct ipmi_user         *user = NULL;
3888         struct ipmi_lan_addr     *lan_addr;
3889         struct ipmi_recv_msg     *recv_msg;
3890
3891         if (msg->rsp_size < 12) {
3892                 /* Message not big enough, just ignore it. */
3893                 ipmi_inc_stat(intf, invalid_commands);
3894                 return 0;
3895         }
3896
3897         if (msg->rsp[2] != 0) {
3898                 /* An error getting the response, just ignore it. */
3899                 return 0;
3900         }
3901
3902         netfn = msg->rsp[6] >> 2;
3903         cmd = msg->rsp[10];
3904         chan = msg->rsp[3] & 0xf;
3905
3906         rcu_read_lock();
3907         rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3908         if (rcvr) {
3909                 user = rcvr->user;
3910                 kref_get(&user->refcount);
3911         } else
3912                 user = NULL;
3913         rcu_read_unlock();
3914
3915         if (user == NULL) {
3916                 /* We didn't find a user, just give up. */
3917                 ipmi_inc_stat(intf, unhandled_commands);
3918
3919                 /*
3920                  * Don't do anything with these messages, just allow
3921                  * them to be freed.
3922                  */
3923                 rv = 0;
3924         } else {
3925                 recv_msg = ipmi_alloc_recv_msg();
3926                 if (!recv_msg) {
3927                         /*
3928                          * We couldn't allocate memory for the
3929                          * message, so requeue it for handling later.
3930                          */
3931                         rv = 1;
3932                         kref_put(&user->refcount, free_user);
3933                 } else {
3934                         /* Extract the source address from the data. */
3935                         lan_addr = (struct ipmi_lan_addr *) &recv_msg->addr;
3936                         lan_addr->addr_type = IPMI_LAN_ADDR_TYPE;
3937                         lan_addr->session_handle = msg->rsp[4];
3938                         lan_addr->remote_SWID = msg->rsp[8];
3939                         lan_addr->local_SWID = msg->rsp[5];
3940                         lan_addr->lun = msg->rsp[9] & 3;
3941                         lan_addr->channel = msg->rsp[3] & 0xf;
3942                         lan_addr->privilege = msg->rsp[3] >> 4;
3943
3944                         /*
3945                          * Extract the rest of the message information
3946                          * from the IPMB header.
3947                          */
3948                         recv_msg->user = user;
3949                         recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3950                         recv_msg->msgid = msg->rsp[9] >> 2;
3951                         recv_msg->msg.netfn = msg->rsp[6] >> 2;
3952                         recv_msg->msg.cmd = msg->rsp[10];
3953                         recv_msg->msg.data = recv_msg->msg_data;
3954
3955                         /*
3956                          * We chop off 12, not 11 bytes because the checksum
3957                          * at the end also needs to be removed.
3958                          */
3959                         recv_msg->msg.data_len = msg->rsp_size - 12;
3960                         memcpy(recv_msg->msg_data, &msg->rsp[11],
3961                                msg->rsp_size - 12);
3962                         if (deliver_response(intf, recv_msg))
3963                                 ipmi_inc_stat(intf, unhandled_commands);
3964                         else
3965                                 ipmi_inc_stat(intf, handled_commands);
3966                 }
3967         }
3968
3969         return rv;
3970 }
3971
3972 /*
3973  * This routine will handle "Get Message" command responses with
3974  * channels that use an OEM Medium. The message format belongs to
3975  * the OEM.  See IPMI 2.0 specification, Chapter 6 and
3976  * Chapter 22, sections 22.6 and 22.24 for more details.
3977  */
3978 static int handle_oem_get_msg_cmd(struct ipmi_smi *intf,
3979                                   struct ipmi_smi_msg *msg)
3980 {
3981         struct cmd_rcvr       *rcvr;
3982         int                   rv = 0;
3983         unsigned char         netfn;
3984         unsigned char         cmd;
3985         unsigned char         chan;
3986         struct ipmi_user *user = NULL;
3987         struct ipmi_system_interface_addr *smi_addr;
3988         struct ipmi_recv_msg  *recv_msg;
3989
3990         /*
3991          * We expect the OEM SW to perform error checking
3992          * so we just do some basic sanity checks
3993          */
3994         if (msg->rsp_size < 4) {
3995                 /* Message not big enough, just ignore it. */
3996                 ipmi_inc_stat(intf, invalid_commands);
3997                 return 0;
3998         }
3999
4000         if (msg->rsp[2] != 0) {
4001                 /* An error getting the response, just ignore it. */
4002                 return 0;
4003         }
4004
4005         /*
4006          * This is an OEM Message so the OEM needs to know how
4007          * handle the message. We do no interpretation.
4008          */
4009         netfn = msg->rsp[0] >> 2;
4010         cmd = msg->rsp[1];
4011         chan = msg->rsp[3] & 0xf;
4012
4013         rcu_read_lock();
4014         rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
4015         if (rcvr) {
4016                 user = rcvr->user;
4017                 kref_get(&user->refcount);
4018         } else
4019                 user = NULL;
4020         rcu_read_unlock();
4021
4022         if (user == NULL) {
4023                 /* We didn't find a user, just give up. */
4024                 ipmi_inc_stat(intf, unhandled_commands);
4025
4026                 /*
4027                  * Don't do anything with these messages, just allow
4028                  * them to be freed.
4029                  */
4030
4031                 rv = 0;
4032         } else {
4033                 recv_msg = ipmi_alloc_recv_msg();
4034                 if (!recv_msg) {
4035                         /*
4036                          * We couldn't allocate memory for the
4037                          * message, so requeue it for handling
4038                          * later.
4039                          */
4040                         rv = 1;
4041                         kref_put(&user->refcount, free_user);
4042                 } else {
4043                         /*
4044                          * OEM Messages are expected to be delivered via
4045                          * the system interface to SMS software.  We might
4046                          * need to visit this again depending on OEM
4047                          * requirements
4048                          */
4049                         smi_addr = ((struct ipmi_system_interface_addr *)
4050                                     &recv_msg->addr);
4051                         smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4052                         smi_addr->channel = IPMI_BMC_CHANNEL;
4053                         smi_addr->lun = msg->rsp[0] & 3;
4054
4055                         recv_msg->user = user;
4056                         recv_msg->user_msg_data = NULL;
4057                         recv_msg->recv_type = IPMI_OEM_RECV_TYPE;
4058                         recv_msg->msg.netfn = msg->rsp[0] >> 2;
4059                         recv_msg->msg.cmd = msg->rsp[1];
4060                         recv_msg->msg.data = recv_msg->msg_data;
4061
4062                         /*
4063                          * The message starts at byte 4 which follows the
4064                          * the Channel Byte in the "GET MESSAGE" command
4065                          */
4066                         recv_msg->msg.data_len = msg->rsp_size - 4;
4067                         memcpy(recv_msg->msg_data, &msg->rsp[4],
4068                                msg->rsp_size - 4);
4069                         if (deliver_response(intf, recv_msg))
4070                                 ipmi_inc_stat(intf, unhandled_commands);
4071                         else
4072                                 ipmi_inc_stat(intf, handled_commands);
4073                 }
4074         }
4075
4076         return rv;
4077 }
4078
4079 static void copy_event_into_recv_msg(struct ipmi_recv_msg *recv_msg,
4080                                      struct ipmi_smi_msg  *msg)
4081 {
4082         struct ipmi_system_interface_addr *smi_addr;
4083
4084         recv_msg->msgid = 0;
4085         smi_addr = (struct ipmi_system_interface_addr *) &recv_msg->addr;
4086         smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4087         smi_addr->channel = IPMI_BMC_CHANNEL;
4088         smi_addr->lun = msg->rsp[0] & 3;
4089         recv_msg->recv_type = IPMI_ASYNC_EVENT_RECV_TYPE;
4090         recv_msg->msg.netfn = msg->rsp[0] >> 2;
4091         recv_msg->msg.cmd = msg->rsp[1];
4092         memcpy(recv_msg->msg_data, &msg->rsp[3], msg->rsp_size - 3);
4093         recv_msg->msg.data = recv_msg->msg_data;
4094         recv_msg->msg.data_len = msg->rsp_size - 3;
4095 }
4096
4097 static int handle_read_event_rsp(struct ipmi_smi *intf,
4098                                  struct ipmi_smi_msg *msg)
4099 {
4100         struct ipmi_recv_msg *recv_msg, *recv_msg2;
4101         struct list_head     msgs;
4102         struct ipmi_user     *user;
4103         int rv = 0, deliver_count = 0, index;
4104         unsigned long        flags;
4105
4106         if (msg->rsp_size < 19) {
4107                 /* Message is too small to be an IPMB event. */
4108                 ipmi_inc_stat(intf, invalid_events);
4109                 return 0;
4110         }
4111
4112         if (msg->rsp[2] != 0) {
4113                 /* An error getting the event, just ignore it. */
4114                 return 0;
4115         }
4116
4117         INIT_LIST_HEAD(&msgs);
4118
4119         spin_lock_irqsave(&intf->events_lock, flags);
4120
4121         ipmi_inc_stat(intf, events);
4122
4123         /*
4124          * Allocate and fill in one message for every user that is
4125          * getting events.
4126          */
4127         index = srcu_read_lock(&intf->users_srcu);
4128         list_for_each_entry_rcu(user, &intf->users, link) {
4129                 if (!user->gets_events)
4130                         continue;
4131
4132                 recv_msg = ipmi_alloc_recv_msg();
4133                 if (!recv_msg) {
4134                         rcu_read_unlock();
4135                         list_for_each_entry_safe(recv_msg, recv_msg2, &msgs,
4136                                                  link) {
4137                                 list_del(&recv_msg->link);
4138                                 ipmi_free_recv_msg(recv_msg);
4139                         }
4140                         /*
4141                          * We couldn't allocate memory for the
4142                          * message, so requeue it for handling
4143                          * later.
4144                          */
4145                         rv = 1;
4146                         goto out;
4147                 }
4148
4149                 deliver_count++;
4150
4151                 copy_event_into_recv_msg(recv_msg, msg);
4152                 recv_msg->user = user;
4153                 kref_get(&user->refcount);
4154                 list_add_tail(&recv_msg->link, &msgs);
4155         }
4156         srcu_read_unlock(&intf->users_srcu, index);
4157
4158         if (deliver_count) {
4159                 /* Now deliver all the messages. */
4160                 list_for_each_entry_safe(recv_msg, recv_msg2, &msgs, link) {
4161                         list_del(&recv_msg->link);
4162                         deliver_local_response(intf, recv_msg);
4163                 }
4164         } else if (intf->waiting_events_count < MAX_EVENTS_IN_QUEUE) {
4165                 /*
4166                  * No one to receive the message, put it in queue if there's
4167                  * not already too many things in the queue.
4168                  */
4169                 recv_msg = ipmi_alloc_recv_msg();
4170                 if (!recv_msg) {
4171                         /*
4172                          * We couldn't allocate memory for the
4173                          * message, so requeue it for handling
4174                          * later.
4175                          */
4176                         rv = 1;
4177                         goto out;
4178                 }
4179
4180                 copy_event_into_recv_msg(recv_msg, msg);
4181                 list_add_tail(&recv_msg->link, &intf->waiting_events);
4182                 intf->waiting_events_count++;
4183         } else if (!intf->event_msg_printed) {
4184                 /*
4185                  * There's too many things in the queue, discard this
4186                  * message.
4187                  */
4188                 dev_warn(intf->si_dev,
4189                          "Event queue full, discarding incoming events\n");
4190                 intf->event_msg_printed = 1;
4191         }
4192
4193  out:
4194         spin_unlock_irqrestore(&intf->events_lock, flags);
4195
4196         return rv;
4197 }
4198
4199 static int handle_bmc_rsp(struct ipmi_smi *intf,
4200                           struct ipmi_smi_msg *msg)
4201 {
4202         struct ipmi_recv_msg *recv_msg;
4203         struct ipmi_system_interface_addr *smi_addr;
4204
4205         recv_msg = (struct ipmi_recv_msg *) msg->user_data;
4206         if (recv_msg == NULL) {
4207                 dev_warn(intf->si_dev,
4208                          "IPMI message received with no owner. This could be because of a malformed message, or because of a hardware error.  Contact your hardware vendor for assistance.\n");
4209                 return 0;
4210         }
4211
4212         recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4213         recv_msg->msgid = msg->msgid;
4214         smi_addr = ((struct ipmi_system_interface_addr *)
4215                     &recv_msg->addr);
4216         smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4217         smi_addr->channel = IPMI_BMC_CHANNEL;
4218         smi_addr->lun = msg->rsp[0] & 3;
4219         recv_msg->msg.netfn = msg->rsp[0] >> 2;
4220         recv_msg->msg.cmd = msg->rsp[1];
4221         memcpy(recv_msg->msg_data, &msg->rsp[2], msg->rsp_size - 2);
4222         recv_msg->msg.data = recv_msg->msg_data;
4223         recv_msg->msg.data_len = msg->rsp_size - 2;
4224         deliver_local_response(intf, recv_msg);
4225
4226         return 0;
4227 }
4228
4229 /*
4230  * Handle a received message.  Return 1 if the message should be requeued,
4231  * 0 if the message should be freed, or -1 if the message should not
4232  * be freed or requeued.
4233  */
4234 static int handle_one_recv_msg(struct ipmi_smi *intf,
4235                                struct ipmi_smi_msg *msg)
4236 {
4237         int requeue;
4238         int chan;
4239
4240         pr_debug("Recv: %*ph\n", msg->rsp_size, msg->rsp);
4241
4242         if ((msg->data_size >= 2)
4243             && (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
4244             && (msg->data[1] == IPMI_SEND_MSG_CMD)
4245             && (msg->user_data == NULL)) {
4246
4247                 if (intf->in_shutdown)
4248                         goto free_msg;
4249
4250                 /*
4251                  * This is the local response to a command send, start
4252                  * the timer for these.  The user_data will not be
4253                  * NULL if this is a response send, and we will let
4254                  * response sends just go through.
4255                  */
4256
4257                 /*
4258                  * Check for errors, if we get certain errors (ones
4259                  * that mean basically we can try again later), we
4260                  * ignore them and start the timer.  Otherwise we
4261                  * report the error immediately.
4262                  */
4263                 if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
4264                     && (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
4265                     && (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
4266                     && (msg->rsp[2] != IPMI_BUS_ERR)
4267                     && (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
4268                         int ch = msg->rsp[3] & 0xf;
4269                         struct ipmi_channel *chans;
4270
4271                         /* Got an error sending the message, handle it. */
4272
4273                         chans = READ_ONCE(intf->channel_list)->c;
4274                         if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
4275                             || (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
4276                                 ipmi_inc_stat(intf, sent_lan_command_errs);
4277                         else
4278                                 ipmi_inc_stat(intf, sent_ipmb_command_errs);
4279                         intf_err_seq(intf, msg->msgid, msg->rsp[2]);
4280                 } else
4281                         /* The message was sent, start the timer. */
4282                         intf_start_seq_timer(intf, msg->msgid);
4283 free_msg:
4284                 requeue = 0;
4285                 goto out;
4286
4287         } else if (msg->rsp_size < 2) {
4288                 /* Message is too small to be correct. */
4289                 dev_warn(intf->si_dev,
4290                          "BMC returned too small a message for netfn %x cmd %x, got %d bytes\n",
4291                          (msg->data[0] >> 2) | 1, msg->data[1], msg->rsp_size);
4292
4293                 /* Generate an error response for the message. */
4294                 msg->rsp[0] = msg->data[0] | (1 << 2);
4295                 msg->rsp[1] = msg->data[1];
4296                 msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4297                 msg->rsp_size = 3;
4298         } else if (((msg->rsp[0] >> 2) != ((msg->data[0] >> 2) | 1))
4299                    || (msg->rsp[1] != msg->data[1])) {
4300                 /*
4301                  * The NetFN and Command in the response is not even
4302                  * marginally correct.
4303                  */
4304                 dev_warn(intf->si_dev,
4305                          "BMC returned incorrect response, expected netfn %x cmd %x, got netfn %x cmd %x\n",
4306                          (msg->data[0] >> 2) | 1, msg->data[1],
4307                          msg->rsp[0] >> 2, msg->rsp[1]);
4308
4309                 /* Generate an error response for the message. */
4310                 msg->rsp[0] = msg->data[0] | (1 << 2);
4311                 msg->rsp[1] = msg->data[1];
4312                 msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4313                 msg->rsp_size = 3;
4314         }
4315
4316         if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4317             && (msg->rsp[1] == IPMI_SEND_MSG_CMD)
4318             && (msg->user_data != NULL)) {
4319                 /*
4320                  * It's a response to a response we sent.  For this we
4321                  * deliver a send message response to the user.
4322                  */
4323                 struct ipmi_recv_msg *recv_msg = msg->user_data;
4324
4325                 requeue = 0;
4326                 if (msg->rsp_size < 2)
4327                         /* Message is too small to be correct. */
4328                         goto out;
4329
4330                 chan = msg->data[2] & 0x0f;
4331                 if (chan >= IPMI_MAX_CHANNELS)
4332                         /* Invalid channel number */
4333                         goto out;
4334
4335                 if (!recv_msg)
4336                         goto out;
4337
4338                 recv_msg->recv_type = IPMI_RESPONSE_RESPONSE_TYPE;
4339                 recv_msg->msg.data = recv_msg->msg_data;
4340                 recv_msg->msg.data_len = 1;
4341                 recv_msg->msg_data[0] = msg->rsp[2];
4342                 deliver_local_response(intf, recv_msg);
4343         } else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4344                    && (msg->rsp[1] == IPMI_GET_MSG_CMD)) {
4345                 struct ipmi_channel   *chans;
4346
4347                 /* It's from the receive queue. */
4348                 chan = msg->rsp[3] & 0xf;
4349                 if (chan >= IPMI_MAX_CHANNELS) {
4350                         /* Invalid channel number */
4351                         requeue = 0;
4352                         goto out;
4353                 }
4354
4355                 /*
4356                  * We need to make sure the channels have been initialized.
4357                  * The channel_handler routine will set the "curr_channel"
4358                  * equal to or greater than IPMI_MAX_CHANNELS when all the
4359                  * channels for this interface have been initialized.
4360                  */
4361                 if (!intf->channels_ready) {
4362                         requeue = 0; /* Throw the message away */
4363                         goto out;
4364                 }
4365
4366                 chans = READ_ONCE(intf->channel_list)->c;
4367
4368                 switch (chans[chan].medium) {
4369                 case IPMI_CHANNEL_MEDIUM_IPMB:
4370                         if (msg->rsp[4] & 0x04) {
4371                                 /*
4372                                  * It's a response, so find the
4373                                  * requesting message and send it up.
4374                                  */
4375                                 requeue = handle_ipmb_get_msg_rsp(intf, msg);
4376                         } else {
4377                                 /*
4378                                  * It's a command to the SMS from some other
4379                                  * entity.  Handle that.
4380                                  */
4381                                 requeue = handle_ipmb_get_msg_cmd(intf, msg);
4382                         }
4383                         break;
4384
4385                 case IPMI_CHANNEL_MEDIUM_8023LAN:
4386                 case IPMI_CHANNEL_MEDIUM_ASYNC:
4387                         if (msg->rsp[6] & 0x04) {
4388                                 /*
4389                                  * It's a response, so find the
4390                                  * requesting message and send it up.
4391                                  */
4392                                 requeue = handle_lan_get_msg_rsp(intf, msg);
4393                         } else {
4394                                 /*
4395                                  * It's a command to the SMS from some other
4396                                  * entity.  Handle that.
4397                                  */
4398                                 requeue = handle_lan_get_msg_cmd(intf, msg);
4399                         }
4400                         break;
4401
4402                 default:
4403                         /* Check for OEM Channels.  Clients had better
4404                            register for these commands. */
4405                         if ((chans[chan].medium >= IPMI_CHANNEL_MEDIUM_OEM_MIN)
4406                             && (chans[chan].medium
4407                                 <= IPMI_CHANNEL_MEDIUM_OEM_MAX)) {
4408                                 requeue = handle_oem_get_msg_cmd(intf, msg);
4409                         } else {
4410                                 /*
4411                                  * We don't handle the channel type, so just
4412                                  * free the message.
4413                                  */
4414                                 requeue = 0;
4415                         }
4416                 }
4417
4418         } else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4419                    && (msg->rsp[1] == IPMI_READ_EVENT_MSG_BUFFER_CMD)) {
4420                 /* It's an asynchronous event. */
4421                 requeue = handle_read_event_rsp(intf, msg);
4422         } else {
4423                 /* It's a response from the local BMC. */
4424                 requeue = handle_bmc_rsp(intf, msg);
4425         }
4426
4427  out:
4428         return requeue;
4429 }
4430
4431 /*
4432  * If there are messages in the queue or pretimeouts, handle them.
4433  */
4434 static void handle_new_recv_msgs(struct ipmi_smi *intf)
4435 {
4436         struct ipmi_smi_msg  *smi_msg;
4437         unsigned long        flags = 0;
4438         int                  rv;
4439         int                  run_to_completion = intf->run_to_completion;
4440
4441         /* See if any waiting messages need to be processed. */
4442         if (!run_to_completion)
4443                 spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4444         while (!list_empty(&intf->waiting_rcv_msgs)) {
4445                 smi_msg = list_entry(intf->waiting_rcv_msgs.next,
4446                                      struct ipmi_smi_msg, link);
4447                 list_del(&smi_msg->link);
4448                 if (!run_to_completion)
4449                         spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4450                                                flags);
4451                 rv = handle_one_recv_msg(intf, smi_msg);
4452                 if (!run_to_completion)
4453                         spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4454                 if (rv > 0) {
4455                         /*
4456                          * To preserve message order, quit if we
4457                          * can't handle a message.  Add the message
4458                          * back at the head, this is safe because this
4459                          * tasklet is the only thing that pulls the
4460                          * messages.
4461                          */
4462                         list_add(&smi_msg->link, &intf->waiting_rcv_msgs);
4463                         break;
4464                 } else {
4465                         if (rv == 0)
4466                                 /* Message handled */
4467                                 ipmi_free_smi_msg(smi_msg);
4468                         /* If rv < 0, fatal error, del but don't free. */
4469                 }
4470         }
4471         if (!run_to_completion)
4472                 spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock, flags);
4473
4474         /*
4475          * If the pretimout count is non-zero, decrement one from it and
4476          * deliver pretimeouts to all the users.
4477          */
4478         if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) {
4479                 struct ipmi_user *user;
4480                 int index;
4481
4482                 index = srcu_read_lock(&intf->users_srcu);
4483                 list_for_each_entry_rcu(user, &intf->users, link) {
4484                         if (user->handler->ipmi_watchdog_pretimeout)
4485                                 user->handler->ipmi_watchdog_pretimeout(
4486                                         user->handler_data);
4487                 }
4488                 srcu_read_unlock(&intf->users_srcu, index);
4489         }
4490 }
4491
4492 static void smi_recv_tasklet(struct tasklet_struct *t)
4493 {
4494         unsigned long flags = 0; /* keep us warning-free. */
4495         struct ipmi_smi *intf = from_tasklet(intf, t, recv_tasklet);
4496         int run_to_completion = intf->run_to_completion;
4497         struct ipmi_smi_msg *newmsg = NULL;
4498
4499         /*
4500          * Start the next message if available.
4501          *
4502          * Do this here, not in the actual receiver, because we may deadlock
4503          * because the lower layer is allowed to hold locks while calling
4504          * message delivery.
4505          */
4506
4507         rcu_read_lock();
4508
4509         if (!run_to_completion)
4510                 spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4511         if (intf->curr_msg == NULL && !intf->in_shutdown) {
4512                 struct list_head *entry = NULL;
4513
4514                 /* Pick the high priority queue first. */
4515                 if (!list_empty(&intf->hp_xmit_msgs))
4516                         entry = intf->hp_xmit_msgs.next;
4517                 else if (!list_empty(&intf->xmit_msgs))
4518                         entry = intf->xmit_msgs.next;
4519
4520                 if (entry) {
4521                         list_del(entry);
4522                         newmsg = list_entry(entry, struct ipmi_smi_msg, link);
4523                         intf->curr_msg = newmsg;
4524                 }
4525         }
4526
4527         if (!run_to_completion)
4528                 spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4529         if (newmsg)
4530                 intf->handlers->sender(intf->send_info, newmsg);
4531
4532         rcu_read_unlock();
4533
4534         handle_new_recv_msgs(intf);
4535 }
4536
4537 /* Handle a new message from the lower layer. */
4538 void ipmi_smi_msg_received(struct ipmi_smi *intf,
4539                            struct ipmi_smi_msg *msg)
4540 {
4541         unsigned long flags = 0; /* keep us warning-free. */
4542         int run_to_completion = intf->run_to_completion;
4543
4544         /*
4545          * To preserve message order, we keep a queue and deliver from
4546          * a tasklet.
4547          */
4548         if (!run_to_completion)
4549                 spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4550         list_add_tail(&msg->link, &intf->waiting_rcv_msgs);
4551         if (!run_to_completion)
4552                 spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4553                                        flags);
4554
4555         if (!run_to_completion)
4556                 spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4557         /*
4558          * We can get an asynchronous event or receive message in addition
4559          * to commands we send.
4560          */
4561         if (msg == intf->curr_msg)
4562                 intf->curr_msg = NULL;
4563         if (!run_to_completion)
4564                 spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4565
4566         if (run_to_completion)
4567                 smi_recv_tasklet(&intf->recv_tasklet);
4568         else
4569                 tasklet_schedule(&intf->recv_tasklet);
4570 }
4571 EXPORT_SYMBOL(ipmi_smi_msg_received);
4572
4573 void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf)
4574 {
4575         if (intf->in_shutdown)
4576                 return;
4577
4578         atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);
4579         tasklet_schedule(&intf->recv_tasklet);
4580 }
4581 EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
4582
4583 static struct ipmi_smi_msg *
4584 smi_from_recv_msg(struct ipmi_smi *intf, struct ipmi_recv_msg *recv_msg,
4585                   unsigned char seq, long seqid)
4586 {
4587         struct ipmi_smi_msg *smi_msg = ipmi_alloc_smi_msg();
4588         if (!smi_msg)
4589                 /*
4590                  * If we can't allocate the message, then just return, we
4591                  * get 4 retries, so this should be ok.
4592                  */
4593                 return NULL;
4594
4595         memcpy(smi_msg->data, recv_msg->msg.data, recv_msg->msg.data_len);
4596         smi_msg->data_size = recv_msg->msg.data_len;
4597         smi_msg->msgid = STORE_SEQ_IN_MSGID(seq, seqid);
4598
4599         pr_debug("Resend: %*ph\n", smi_msg->data_size, smi_msg->data);
4600
4601         return smi_msg;
4602 }
4603
4604 static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent,
4605                               struct list_head *timeouts,
4606                               unsigned long timeout_period,
4607                               int slot, unsigned long *flags,
4608                               bool *need_timer)
4609 {
4610         struct ipmi_recv_msg *msg;
4611
4612         if (intf->in_shutdown)
4613                 return;
4614
4615         if (!ent->inuse)
4616                 return;
4617
4618         if (timeout_period < ent->timeout) {
4619                 ent->timeout -= timeout_period;
4620                 *need_timer = true;
4621                 return;
4622         }
4623
4624         if (ent->retries_left == 0) {
4625                 /* The message has used all its retries. */
4626                 ent->inuse = 0;
4627                 smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
4628                 msg = ent->recv_msg;
4629                 list_add_tail(&msg->link, timeouts);
4630                 if (ent->broadcast)
4631                         ipmi_inc_stat(intf, timed_out_ipmb_broadcasts);
4632                 else if (is_lan_addr(&ent->recv_msg->addr))
4633                         ipmi_inc_stat(intf, timed_out_lan_commands);
4634                 else
4635                         ipmi_inc_stat(intf, timed_out_ipmb_commands);
4636         } else {
4637                 struct ipmi_smi_msg *smi_msg;
4638                 /* More retries, send again. */
4639
4640                 *need_timer = true;
4641
4642                 /*
4643                  * Start with the max timer, set to normal timer after
4644                  * the message is sent.
4645                  */
4646                 ent->timeout = MAX_MSG_TIMEOUT;
4647                 ent->retries_left--;
4648                 smi_msg = smi_from_recv_msg(intf, ent->recv_msg, slot,
4649                                             ent->seqid);
4650                 if (!smi_msg) {
4651                         if (is_lan_addr(&ent->recv_msg->addr))
4652                                 ipmi_inc_stat(intf,
4653                                               dropped_rexmit_lan_commands);
4654                         else
4655                                 ipmi_inc_stat(intf,
4656                                               dropped_rexmit_ipmb_commands);
4657                         return;
4658                 }
4659
4660                 spin_unlock_irqrestore(&intf->seq_lock, *flags);
4661
4662                 /*
4663                  * Send the new message.  We send with a zero
4664                  * priority.  It timed out, I doubt time is that
4665                  * critical now, and high priority messages are really
4666                  * only for messages to the local MC, which don't get
4667                  * resent.
4668                  */
4669                 if (intf->handlers) {
4670                         if (is_lan_addr(&ent->recv_msg->addr))
4671                                 ipmi_inc_stat(intf,
4672                                               retransmitted_lan_commands);
4673                         else
4674                                 ipmi_inc_stat(intf,
4675                                               retransmitted_ipmb_commands);
4676
4677                         smi_send(intf, intf->handlers, smi_msg, 0);
4678                 } else
4679                         ipmi_free_smi_msg(smi_msg);
4680
4681                 spin_lock_irqsave(&intf->seq_lock, *flags);
4682         }
4683 }
4684
4685 static bool ipmi_timeout_handler(struct ipmi_smi *intf,
4686                                  unsigned long timeout_period)
4687 {
4688         struct list_head     timeouts;
4689         struct ipmi_recv_msg *msg, *msg2;
4690         unsigned long        flags;
4691         int                  i;
4692         bool                 need_timer = false;
4693
4694         if (!intf->bmc_registered) {
4695                 kref_get(&intf->refcount);
4696                 if (!schedule_work(&intf->bmc_reg_work)) {
4697                         kref_put(&intf->refcount, intf_free);
4698                         need_timer = true;
4699                 }
4700         }
4701
4702         /*
4703          * Go through the seq table and find any messages that
4704          * have timed out, putting them in the timeouts
4705          * list.
4706          */
4707         INIT_LIST_HEAD(&timeouts);
4708         spin_lock_irqsave(&intf->seq_lock, flags);
4709         if (intf->ipmb_maintenance_mode_timeout) {
4710                 if (intf->ipmb_maintenance_mode_timeout <= timeout_period)
4711                         intf->ipmb_maintenance_mode_timeout = 0;
4712                 else
4713                         intf->ipmb_maintenance_mode_timeout -= timeout_period;
4714         }
4715         for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
4716                 check_msg_timeout(intf, &intf->seq_table[i],
4717                                   &timeouts, timeout_period, i,
4718                                   &flags, &need_timer);
4719         spin_unlock_irqrestore(&intf->seq_lock, flags);
4720
4721         list_for_each_entry_safe(msg, msg2, &timeouts, link)
4722                 deliver_err_response(intf, msg, IPMI_TIMEOUT_COMPLETION_CODE);
4723
4724         /*
4725          * Maintenance mode handling.  Check the timeout
4726          * optimistically before we claim the lock.  It may
4727          * mean a timeout gets missed occasionally, but that
4728          * only means the timeout gets extended by one period
4729          * in that case.  No big deal, and it avoids the lock
4730          * most of the time.
4731          */
4732         if (intf->auto_maintenance_timeout > 0) {
4733                 spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
4734                 if (intf->auto_maintenance_timeout > 0) {
4735                         intf->auto_maintenance_timeout
4736                                 -= timeout_period;
4737                         if (!intf->maintenance_mode
4738                             && (intf->auto_maintenance_timeout <= 0)) {
4739                                 intf->maintenance_mode_enable = false;
4740                                 maintenance_mode_update(intf);
4741                         }
4742                 }
4743                 spin_unlock_irqrestore(&intf->maintenance_mode_lock,
4744                                        flags);
4745         }
4746
4747         tasklet_schedule(&intf->recv_tasklet);
4748
4749         return need_timer;
4750 }
4751
4752 static void ipmi_request_event(struct ipmi_smi *intf)
4753 {
4754         /* No event requests when in maintenance mode. */
4755         if (intf->maintenance_mode_enable)
4756                 return;
4757
4758         if (!intf->in_shutdown)
4759                 intf->handlers->request_events(intf->send_info);
4760 }
4761
4762 static struct timer_list ipmi_timer;
4763
4764 static atomic_t stop_operation;
4765
4766 static void ipmi_timeout(struct timer_list *unused)
4767 {
4768         struct ipmi_smi *intf;
4769         bool need_timer = false;
4770         int index;
4771
4772         if (atomic_read(&stop_operation))
4773                 return;
4774
4775         index = srcu_read_lock(&ipmi_interfaces_srcu);
4776         list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
4777                 if (atomic_read(&intf->event_waiters)) {
4778                         intf->ticks_to_req_ev--;
4779                         if (intf->ticks_to_req_ev == 0) {
4780                                 ipmi_request_event(intf);
4781                                 intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
4782                         }
4783                         need_timer = true;
4784                 }
4785
4786                 need_timer |= ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
4787         }
4788         srcu_read_unlock(&ipmi_interfaces_srcu, index);
4789
4790         if (need_timer)
4791                 mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
4792 }
4793
4794 static void need_waiter(struct ipmi_smi *intf)
4795 {
4796         /* Racy, but worst case we start the timer twice. */
4797         if (!timer_pending(&ipmi_timer))
4798                 mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
4799 }
4800
4801 static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
4802 static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);
4803
4804 static void free_smi_msg(struct ipmi_smi_msg *msg)
4805 {
4806         atomic_dec(&smi_msg_inuse_count);
4807         /* Try to keep as much stuff out of the panic path as possible. */
4808         if (!oops_in_progress)
4809                 kfree(msg);
4810 }
4811
4812 struct ipmi_smi_msg *ipmi_alloc_smi_msg(void)
4813 {
4814         struct ipmi_smi_msg *rv;
4815         rv = kmalloc(sizeof(struct ipmi_smi_msg), GFP_ATOMIC);
4816         if (rv) {
4817                 rv->done = free_smi_msg;
4818                 rv->user_data = NULL;
4819                 atomic_inc(&smi_msg_inuse_count);
4820         }
4821         return rv;
4822 }
4823 EXPORT_SYMBOL(ipmi_alloc_smi_msg);
4824
4825 static void free_recv_msg(struct ipmi_recv_msg *msg)
4826 {
4827         atomic_dec(&recv_msg_inuse_count);
4828         /* Try to keep as much stuff out of the panic path as possible. */
4829         if (!oops_in_progress)
4830                 kfree(msg);
4831 }
4832
4833 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void)
4834 {
4835         struct ipmi_recv_msg *rv;
4836
4837         rv = kmalloc(sizeof(struct ipmi_recv_msg), GFP_ATOMIC);
4838         if (rv) {
4839                 rv->user = NULL;
4840                 rv->done = free_recv_msg;
4841                 atomic_inc(&recv_msg_inuse_count);
4842         }
4843         return rv;
4844 }
4845
4846 void ipmi_free_recv_msg(struct ipmi_recv_msg *msg)
4847 {
4848         if (msg->user && !oops_in_progress)
4849                 kref_put(&msg->user->refcount, free_user);
4850         msg->done(msg);
4851 }
4852 EXPORT_SYMBOL(ipmi_free_recv_msg);
4853
4854 static atomic_t panic_done_count = ATOMIC_INIT(0);
4855
4856 static void dummy_smi_done_handler(struct ipmi_smi_msg *msg)
4857 {
4858         atomic_dec(&panic_done_count);
4859 }
4860
4861 static void dummy_recv_done_handler(struct ipmi_recv_msg *msg)
4862 {
4863         atomic_dec(&panic_done_count);
4864 }
4865
4866 /*
4867  * Inside a panic, send a message and wait for a response.
4868  */
4869 static void ipmi_panic_request_and_wait(struct ipmi_smi *intf,
4870                                         struct ipmi_addr *addr,
4871                                         struct kernel_ipmi_msg *msg)
4872 {
4873         struct ipmi_smi_msg  smi_msg;
4874         struct ipmi_recv_msg recv_msg;
4875         int rv;
4876
4877         smi_msg.done = dummy_smi_done_handler;
4878         recv_msg.done = dummy_recv_done_handler;
4879         atomic_add(2, &panic_done_count);
4880         rv = i_ipmi_request(NULL,
4881                             intf,
4882                             addr,
4883                             0,
4884                             msg,
4885                             intf,
4886                             &smi_msg,
4887                             &recv_msg,
4888                             0,
4889                             intf->addrinfo[0].address,
4890                             intf->addrinfo[0].lun,
4891                             0, 1); /* Don't retry, and don't wait. */
4892         if (rv)
4893                 atomic_sub(2, &panic_done_count);
4894         else if (intf->handlers->flush_messages)
4895                 intf->handlers->flush_messages(intf->send_info);
4896
4897         while (atomic_read(&panic_done_count) != 0)
4898                 ipmi_poll(intf);
4899 }
4900
4901 static void event_receiver_fetcher(struct ipmi_smi *intf,
4902                                    struct ipmi_recv_msg *msg)
4903 {
4904         if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
4905             && (msg->msg.netfn == IPMI_NETFN_SENSOR_EVENT_RESPONSE)
4906             && (msg->msg.cmd == IPMI_GET_EVENT_RECEIVER_CMD)
4907             && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
4908                 /* A get event receiver command, save it. */
4909                 intf->event_receiver = msg->msg.data[1];
4910                 intf->event_receiver_lun = msg->msg.data[2] & 0x3;
4911         }
4912 }
4913
4914 static void device_id_fetcher(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
4915 {
4916         if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
4917             && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
4918             && (msg->msg.cmd == IPMI_GET_DEVICE_ID_CMD)
4919             && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
4920                 /*
4921                  * A get device id command, save if we are an event
4922                  * receiver or generator.
4923                  */
4924                 intf->local_sel_device = (msg->msg.data[6] >> 2) & 1;
4925                 intf->local_event_generator = (msg->msg.data[6] >> 5) & 1;
4926         }
4927 }
4928
4929 static void send_panic_events(struct ipmi_smi *intf, char *str)
4930 {
4931         struct kernel_ipmi_msg msg;
4932         unsigned char data[16];
4933         struct ipmi_system_interface_addr *si;
4934         struct ipmi_addr addr;
4935         char *p = str;
4936         struct ipmi_ipmb_addr *ipmb;
4937         int j;
4938
4939         if (ipmi_send_panic_event == IPMI_SEND_PANIC_EVENT_NONE)
4940                 return;
4941
4942         si = (struct ipmi_system_interface_addr *) &addr;
4943         si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4944         si->channel = IPMI_BMC_CHANNEL;
4945         si->lun = 0;
4946
4947         /* Fill in an event telling that we have failed. */
4948         msg.netfn = 0x04; /* Sensor or Event. */
4949         msg.cmd = 2; /* Platform event command. */
4950         msg.data = data;
4951         msg.data_len = 8;
4952         data[0] = 0x41; /* Kernel generator ID, IPMI table 5-4 */
4953         data[1] = 0x03; /* This is for IPMI 1.0. */
4954         data[2] = 0x20; /* OS Critical Stop, IPMI table 36-3 */
4955         data[4] = 0x6f; /* Sensor specific, IPMI table 36-1 */
4956         data[5] = 0xa1; /* Runtime stop OEM bytes 2 & 3. */
4957
4958         /*
4959          * Put a few breadcrumbs in.  Hopefully later we can add more things
4960          * to make the panic events more useful.
4961          */
4962         if (str) {
4963                 data[3] = str[0];
4964                 data[6] = str[1];
4965                 data[7] = str[2];
4966         }
4967
4968         /* Send the event announcing the panic. */
4969         ipmi_panic_request_and_wait(intf, &addr, &msg);
4970
4971         /*
4972          * On every interface, dump a bunch of OEM event holding the
4973          * string.
4974          */
4975         if (ipmi_send_panic_event != IPMI_SEND_PANIC_EVENT_STRING || !str)
4976                 return;
4977
4978         /*
4979          * intf_num is used as an marker to tell if the
4980          * interface is valid.  Thus we need a read barrier to
4981          * make sure data fetched before checking intf_num
4982          * won't be used.
4983          */
4984         smp_rmb();
4985
4986         /*
4987          * First job here is to figure out where to send the
4988          * OEM events.  There's no way in IPMI to send OEM
4989          * events using an event send command, so we have to
4990          * find the SEL to put them in and stick them in
4991          * there.
4992          */
4993
4994         /* Get capabilities from the get device id. */
4995         intf->local_sel_device = 0;
4996         intf->local_event_generator = 0;
4997         intf->event_receiver = 0;
4998
4999         /* Request the device info from the local MC. */
5000         msg.netfn = IPMI_NETFN_APP_REQUEST;
5001         msg.cmd = IPMI_GET_DEVICE_ID_CMD;
5002         msg.data = NULL;
5003         msg.data_len = 0;
5004         intf->null_user_handler = device_id_fetcher;
5005         ipmi_panic_request_and_wait(intf, &addr, &msg);
5006
5007         if (intf->local_event_generator) {
5008                 /* Request the event receiver from the local MC. */
5009                 msg.netfn = IPMI_NETFN_SENSOR_EVENT_REQUEST;
5010                 msg.cmd = IPMI_GET_EVENT_RECEIVER_CMD;
5011                 msg.data = NULL;
5012                 msg.data_len = 0;
5013                 intf->null_user_handler = event_receiver_fetcher;
5014                 ipmi_panic_request_and_wait(intf, &addr, &msg);
5015         }
5016         intf->null_user_handler = NULL;
5017
5018         /*
5019          * Validate the event receiver.  The low bit must not
5020          * be 1 (it must be a valid IPMB address), it cannot
5021          * be zero, and it must not be my address.
5022          */
5023         if (((intf->event_receiver & 1) == 0)
5024             && (intf->event_receiver != 0)
5025             && (intf->event_receiver != intf->addrinfo[0].address)) {
5026                 /*
5027                  * The event receiver is valid, send an IPMB
5028                  * message.
5029                  */
5030                 ipmb = (struct ipmi_ipmb_addr *) &addr;
5031                 ipmb->addr_type = IPMI_IPMB_ADDR_TYPE;
5032                 ipmb->channel = 0; /* FIXME - is this right? */
5033                 ipmb->lun = intf->event_receiver_lun;
5034                 ipmb->slave_addr = intf->event_receiver;
5035         } else if (intf->local_sel_device) {
5036                 /*
5037                  * The event receiver was not valid (or was
5038                  * me), but I am an SEL device, just dump it
5039                  * in my SEL.
5040                  */
5041                 si = (struct ipmi_system_interface_addr *) &addr;
5042                 si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5043                 si->channel = IPMI_BMC_CHANNEL;
5044                 si->lun = 0;
5045         } else
5046                 return; /* No where to send the event. */
5047
5048         msg.netfn = IPMI_NETFN_STORAGE_REQUEST; /* Storage. */
5049         msg.cmd = IPMI_ADD_SEL_ENTRY_CMD;
5050         msg.data = data;
5051         msg.data_len = 16;
5052
5053         j = 0;
5054         while (*p) {
5055                 int size = strlen(p);
5056
5057                 if (size > 11)
5058                         size = 11;
5059                 data[0] = 0;
5060                 data[1] = 0;
5061                 data[2] = 0xf0; /* OEM event without timestamp. */
5062                 data[3] = intf->addrinfo[0].address;
5063                 data[4] = j++; /* sequence # */
5064                 /*
5065                  * Always give 11 bytes, so strncpy will fill
5066                  * it with zeroes for me.
5067                  */
5068                 strncpy(data+5, p, 11);
5069                 p += size;
5070
5071                 ipmi_panic_request_and_wait(intf, &addr, &msg);
5072         }
5073 }
5074
5075 static int has_panicked;
5076
5077 static int panic_event(struct notifier_block *this,
5078                        unsigned long         event,
5079                        void                  *ptr)
5080 {
5081         struct ipmi_smi *intf;
5082         struct ipmi_user *user;
5083
5084         if (has_panicked)
5085                 return NOTIFY_DONE;
5086         has_panicked = 1;
5087
5088         /* For every registered interface, set it to run to completion. */
5089         list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
5090                 if (!intf->handlers || intf->intf_num == -1)
5091                         /* Interface is not ready. */
5092                         continue;
5093
5094                 if (!intf->handlers->poll)
5095                         continue;
5096
5097                 /*
5098                  * If we were interrupted while locking xmit_msgs_lock or
5099                  * waiting_rcv_msgs_lock, the corresponding list may be
5100                  * corrupted.  In this case, drop items on the list for
5101                  * the safety.
5102                  */
5103                 if (!spin_trylock(&intf->xmit_msgs_lock)) {
5104                         INIT_LIST_HEAD(&intf->xmit_msgs);
5105                         INIT_LIST_HEAD(&intf->hp_xmit_msgs);
5106                 } else
5107                         spin_unlock(&intf->xmit_msgs_lock);
5108
5109                 if (!spin_trylock(&intf->waiting_rcv_msgs_lock))
5110                         INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
5111                 else
5112                         spin_unlock(&intf->waiting_rcv_msgs_lock);
5113
5114                 intf->run_to_completion = 1;
5115                 if (intf->handlers->set_run_to_completion)
5116                         intf->handlers->set_run_to_completion(intf->send_info,
5117                                                               1);
5118
5119                 list_for_each_entry_rcu(user, &intf->users, link) {
5120                         if (user->handler->ipmi_panic_handler)
5121                                 user->handler->ipmi_panic_handler(
5122                                         user->handler_data);
5123                 }
5124
5125                 send_panic_events(intf, ptr);
5126         }
5127
5128         return NOTIFY_DONE;
5129 }
5130
5131 /* Must be called with ipmi_interfaces_mutex held. */
5132 static int ipmi_register_driver(void)
5133 {
5134         int rv;
5135
5136         if (drvregistered)
5137                 return 0;
5138
5139         rv = driver_register(&ipmidriver.driver);
5140         if (rv)
5141                 pr_err("Could not register IPMI driver\n");
5142         else
5143                 drvregistered = true;
5144         return rv;
5145 }
5146
5147 static struct notifier_block panic_block = {
5148         .notifier_call  = panic_event,
5149         .next           = NULL,
5150         .priority       = 200   /* priority: INT_MAX >= x >= 0 */
5151 };
5152
5153 static int ipmi_init_msghandler(void)
5154 {
5155         int rv;
5156
5157         mutex_lock(&ipmi_interfaces_mutex);
5158         rv = ipmi_register_driver();
5159         if (rv)
5160                 goto out;
5161         if (initialized)
5162                 goto out;
5163
5164         rv = init_srcu_struct(&ipmi_interfaces_srcu);
5165         if (rv)
5166                 goto out;
5167
5168         remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq");
5169         if (!remove_work_wq) {
5170                 pr_err("unable to create ipmi-msghandler-remove-wq workqueue");
5171                 rv = -ENOMEM;
5172                 goto out_wq;
5173         }
5174
5175         timer_setup(&ipmi_timer, ipmi_timeout, 0);
5176         mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5177
5178         atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
5179
5180         initialized = true;
5181
5182 out_wq:
5183         if (rv)
5184                 cleanup_srcu_struct(&ipmi_interfaces_srcu);
5185 out:
5186         mutex_unlock(&ipmi_interfaces_mutex);
5187         return rv;
5188 }
5189
5190 static int __init ipmi_init_msghandler_mod(void)
5191 {
5192         int rv;
5193
5194         pr_info("version " IPMI_DRIVER_VERSION "\n");
5195
5196         mutex_lock(&ipmi_interfaces_mutex);
5197         rv = ipmi_register_driver();
5198         mutex_unlock(&ipmi_interfaces_mutex);
5199
5200         return rv;
5201 }
5202
5203 static void __exit cleanup_ipmi(void)
5204 {
5205         int count;
5206
5207         if (initialized) {
5208                 destroy_workqueue(remove_work_wq);
5209
5210                 atomic_notifier_chain_unregister(&panic_notifier_list,
5211                                                  &panic_block);
5212
5213                 /*
5214                  * This can't be called if any interfaces exist, so no worry
5215                  * about shutting down the interfaces.
5216                  */
5217
5218                 /*
5219                  * Tell the timer to stop, then wait for it to stop.  This
5220                  * avoids problems with race conditions removing the timer
5221                  * here.
5222                  */
5223                 atomic_set(&stop_operation, 1);
5224                 del_timer_sync(&ipmi_timer);
5225
5226                 initialized = false;
5227
5228                 /* Check for buffer leaks. */
5229                 count = atomic_read(&smi_msg_inuse_count);
5230                 if (count != 0)
5231                         pr_warn("SMI message count %d at exit\n", count);
5232                 count = atomic_read(&recv_msg_inuse_count);
5233                 if (count != 0)
5234                         pr_warn("recv message count %d at exit\n", count);
5235
5236                 cleanup_srcu_struct(&ipmi_interfaces_srcu);
5237         }
5238         if (drvregistered)
5239                 driver_unregister(&ipmidriver.driver);
5240 }
5241 module_exit(cleanup_ipmi);
5242
5243 module_init(ipmi_init_msghandler_mod);
5244 MODULE_LICENSE("GPL");
5245 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
5246 MODULE_DESCRIPTION("Incoming and outgoing message routing for an IPMI"
5247                    " interface.");
5248 MODULE_VERSION(IPMI_DRIVER_VERSION);
5249 MODULE_SOFTDEP("post: ipmi_devintf");