drivers/char/ipmi/ipmi_ssif.c

   1 /*
   2  * ipmi_ssif.c
   3  *
   4  * The interface to the IPMI driver for SMBus access to a SMBus
   5  * compliant device.  Called SSIF by the IPMI spec.
   6  *
   7  * Author: Intel Corporation
   8  *         Todd Davis <todd.c.davis@intel.com>
   9  *
  10  * Rewritten by Corey Minyard <minyard@acm.org> to support the
  11  * non-blocking I2C interface, add support for multi-part
  12  * transactions, add PEC support, and general clenaup.
  13  *
  14  * Copyright 2003 Intel Corporation
  15  * Copyright 2005 MontaVista Software
  16  *
  17  *  This program is free software; you can redistribute it and/or modify it
  18  *  under the terms of the GNU General Public License as published by the
  19  *  Free Software Foundation; either version 2 of the License, or (at your
  20  *  option) any later version.
  21  */
  22
  23 /*
  24  * This file holds the "policy" for the interface to the SSIF state
  25  * machine.  It does the configuration, handles timers and interrupts,
  26  * and drives the real SSIF state machine.
  27  */
  28
  29 /*
  30  * TODO: Figure out how to use SMB alerts.  This will require a new
  31  * interface into the I2C driver, I believe.
  32  */
  33
  34 #if defined(MODVERSIONS)
  35 #include <linux/modversions.h>
  36 #endif
  37
  38 #include <linux/module.h>
  39 #include <linux/moduleparam.h>
  40 #include <linux/sched.h>
  41 #include <linux/seq_file.h>
  42 #include <linux/timer.h>
  43 #include <linux/delay.h>
  44 #include <linux/errno.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/slab.h>
  47 #include <linux/list.h>
  48 #include <linux/i2c.h>
  49 #include <linux/ipmi_smi.h>
  50 #include <linux/init.h>
  51 #include <linux/dmi.h>
  52 #include <linux/kthread.h>
  53 #include <linux/acpi.h>
  54 #include <linux/ctype.h>
  55 #include <linux/time64.h>
  56
  57 #define PFX "ipmi_ssif: "
  58 #define DEVICE_NAME "ipmi_ssif"
  59
  60 #define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD      0x57
  61
  62 #define SSIF_IPMI_REQUEST                       2
  63 #define SSIF_IPMI_MULTI_PART_REQUEST_START      6
  64 #define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE     7
  65 #define SSIF_IPMI_RESPONSE                      3
  66 #define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE    9
  67
  68 /* ssif_debug is a bit-field
  69  *      SSIF_DEBUG_MSG -        commands and their responses
  70  *      SSIF_DEBUG_STATES -     message states
  71  *      SSIF_DEBUG_TIMING -      Measure times between events in the driver
  72  */
  73 #define SSIF_DEBUG_TIMING       4
  74 #define SSIF_DEBUG_STATE        2
  75 #define SSIF_DEBUG_MSG          1
  76 #define SSIF_NODEBUG            0
  77 #define SSIF_DEFAULT_DEBUG      (SSIF_NODEBUG)
  78
  79 /*
  80  * Timer values
  81  */
  82 #define SSIF_MSG_USEC           20000   /* 20ms between message tries. */
  83 #define SSIF_MSG_PART_USEC      5000    /* 5ms for a message part */
  84
  85 /* How many times to we retry sending/receiving the message. */
  86 #define SSIF_SEND_RETRIES       5
  87 #define SSIF_RECV_RETRIES       250
  88
  89 #define SSIF_MSG_MSEC           (SSIF_MSG_USEC / 1000)
  90 #define SSIF_MSG_JIFFIES        ((SSIF_MSG_USEC * 1000) / TICK_NSEC)
  91 #define SSIF_MSG_PART_JIFFIES   ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
  92
  93 enum ssif_intf_state {
  94         SSIF_NORMAL,
  95         SSIF_GETTING_FLAGS,
  96         SSIF_GETTING_EVENTS,
  97         SSIF_CLEARING_FLAGS,
  98         SSIF_GETTING_MESSAGES,
  99         /* FIXME - add watchdog stuff. */
 100 };
 101
 102 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
 103                           && (ssif)->curr_msg == NULL)
 104
 105 /*
 106  * Indexes into stats[] in ssif_info below.
 107  */
 108 enum ssif_stat_indexes {
 109         /* Number of total messages sent. */
 110         SSIF_STAT_sent_messages = 0,
 111
 112         /*
 113          * Number of message parts sent.  Messages may be broken into
 114          * parts if they are long.
 115          */
 116         SSIF_STAT_sent_messages_parts,
 117
 118         /*
 119          * Number of time a message was retried.
 120          */
 121         SSIF_STAT_send_retries,
 122
 123         /*
 124          * Number of times the send of a message failed.
 125          */
 126         SSIF_STAT_send_errors,
 127
 128         /*
 129          * Number of message responses received.
 130          */
 131         SSIF_STAT_received_messages,
 132
 133         /*
 134          * Number of message fragments received.
 135          */
 136         SSIF_STAT_received_message_parts,
 137
 138         /*
 139          * Number of times the receive of a message was retried.
 140          */
 141         SSIF_STAT_receive_retries,
 142
 143         /*
 144          * Number of errors receiving messages.
 145          */
 146         SSIF_STAT_receive_errors,
 147
 148         /*
 149          * Number of times a flag fetch was requested.
 150          */
 151         SSIF_STAT_flag_fetches,
 152
 153         /*
 154          * Number of times the hardware didn't follow the state machine.
 155          */
 156         SSIF_STAT_hosed,
 157
 158         /*
 159          * Number of received events.
 160          */
 161         SSIF_STAT_events,
 162
 163         /* Number of asyncronous messages received. */
 164         SSIF_STAT_incoming_messages,
 165
 166         /* Number of watchdog pretimeouts. */
 167         SSIF_STAT_watchdog_pretimeouts,
 168
 169         /* Number of alers received. */
 170         SSIF_STAT_alerts,
 171
 172         /* Always add statistics before this value, it must be last. */
 173         SSIF_NUM_STATS
 174 };
 175
 176 struct ssif_addr_info {
 177         unsigned short addr;
 178         struct i2c_board_info binfo;
 179         char *adapter_name;
 180         int debug;
 181         int slave_addr;
 182         enum ipmi_addr_src addr_src;
 183         union ipmi_smi_info_union addr_info;
 184
 185         struct mutex clients_mutex;
 186         struct list_head clients;
 187
 188         struct list_head link;
 189 };
 190
 191 struct ssif_info;
 192
 193 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
 194                              unsigned char *data, unsigned int len);
 195
 196 struct ssif_info {
 197         ipmi_smi_t          intf;
 198         int                 intf_num;
 199         spinlock_t          lock;
 200         struct ipmi_smi_msg *waiting_msg;
 201         struct ipmi_smi_msg *curr_msg;
 202         enum ssif_intf_state ssif_state;
 203         unsigned long       ssif_debug;
 204
 205         struct ipmi_smi_handlers handlers;
 206
 207         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
 208         union ipmi_smi_info_union addr_info;
 209
 210         /*
 211          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 212          * is set to hold the flags until we are done handling everything
 213          * from the flags.
 214          */
 215 #define RECEIVE_MSG_AVAIL       0x01
 216 #define EVENT_MSG_BUFFER_FULL   0x02
 217 #define WDT_PRE_TIMEOUT_INT     0x08
 218         unsigned char       msg_flags;
 219
 220         u8                  global_enables;
 221         bool                has_event_buffer;
 222         bool                supports_alert;
 223
 224         /*
 225          * Used to tell what we should do with alerts.  If we are
 226          * waiting on a response, read the data immediately.
 227          */
 228         bool                got_alert;
 229         bool                waiting_alert;
 230
 231         /*
 232          * If set to true, this will request events the next time the
 233          * state machine is idle.
 234          */
 235         bool                req_events;
 236
 237         /*
 238          * If set to true, this will request flags the next time the
 239          * state machine is idle.
 240          */
 241         bool                req_flags;
 242
 243         /*
 244          * Used to perform timer operations when run-to-completion
 245          * mode is on.  This is a countdown timer.
 246          */
 247         int                 rtc_us_timer;
 248
 249         /* Used for sending/receiving data.  +1 for the length. */
 250         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
 251         unsigned int  data_len;
 252
 253         /* Temp receive buffer, gets copied into data. */
 254         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
 255
 256         struct i2c_client *client;
 257         ssif_i2c_done done_handler;
 258
 259         /* Thread interface handling */
 260         struct task_struct *thread;
 261         struct completion wake_thread;
 262         bool stopping;
 263         int i2c_read_write;
 264         int i2c_command;
 265         unsigned char *i2c_data;
 266         unsigned int i2c_size;
 267
 268         /* From the device id response. */
 269         struct ipmi_device_id device_id;
 270
 271         struct timer_list retry_timer;
 272         int retries_left;
 273
 274         /* Info from SSIF cmd */
 275         unsigned char max_xmit_msg_size;
 276         unsigned char max_recv_msg_size;
 277         unsigned int  multi_support;
 278         int           supports_pec;
 279
 280 #define SSIF_NO_MULTI           0
 281 #define SSIF_MULTI_2_PART       1
 282 #define SSIF_MULTI_n_PART       2
 283         unsigned char *multi_data;
 284         unsigned int  multi_len;
 285         unsigned int  multi_pos;
 286
 287         atomic_t stats[SSIF_NUM_STATS];
 288 };
 289
 290 #define ssif_inc_stat(ssif, stat) \
 291         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
 292 #define ssif_get_stat(ssif, stat) \
 293         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
 294
 295 static bool initialized;
 296
 297 static atomic_t next_intf = ATOMIC_INIT(0);
 298
 299 static void return_hosed_msg(struct ssif_info *ssif_info,
 300                              struct ipmi_smi_msg *msg);
 301 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
 302 static int start_send(struct ssif_info *ssif_info,
 303                       unsigned char   *data,
 304                       unsigned int    len);
 305
 306 static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
 307                                           unsigned long *flags)
 308 {
 309         spin_lock_irqsave(&ssif_info->lock, *flags);
 310         return flags;
 311 }
 312
 313 static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
 314                                   unsigned long *flags)
 315 {
 316         spin_unlock_irqrestore(&ssif_info->lock, *flags);
 317 }
 318
 319 static void deliver_recv_msg(struct ssif_info *ssif_info,
 320                              struct ipmi_smi_msg *msg)
 321 {
 322         ipmi_smi_t    intf = ssif_info->intf;
 323
 324         if (!intf) {
 325                 ipmi_free_smi_msg(msg);
 326         } else if (msg->rsp_size < 0) {
 327                 return_hosed_msg(ssif_info, msg);
 328                 pr_err(PFX
 329                        "Malformed message in deliver_recv_msg: rsp_size = %d\n",
 330                        msg->rsp_size);
 331         } else {
 332                 ipmi_smi_msg_received(intf, msg);
 333         }
 334 }
 335
 336 static void return_hosed_msg(struct ssif_info *ssif_info,
 337                              struct ipmi_smi_msg *msg)
 338 {
 339         ssif_inc_stat(ssif_info, hosed);
 340
 341         /* Make it a response */
 342         msg->rsp[0] = msg->data[0] | 4;
 343         msg->rsp[1] = msg->data[1];
 344         msg->rsp[2] = 0xFF; /* Unknown error. */
 345         msg->rsp_size = 3;
 346
 347         deliver_recv_msg(ssif_info, msg);
 348 }
 349
 350 /*
 351  * Must be called with the message lock held.  This will release the
 352  * message lock.  Note that the caller will check SSIF_IDLE and start a
 353  * new operation, so there is no need to check for new messages to
 354  * start in here.
 355  */
 356 static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
 357 {
 358         unsigned char msg[3];
 359
 360         ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
 361         ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
 362         ipmi_ssif_unlock_cond(ssif_info, flags);
 363
 364         /* Make sure the watchdog pre-timeout flag is not set at startup. */
 365         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 366         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
 367         msg[2] = WDT_PRE_TIMEOUT_INT;
 368
 369         if (start_send(ssif_info, msg, 3) != 0) {
 370                 /* Error, just go to normal state. */
 371                 ssif_info->ssif_state = SSIF_NORMAL;
 372         }
 373 }
 374
 375 static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 376 {
 377         unsigned char mb[2];
 378
 379         ssif_info->req_flags = false;
 380         ssif_info->ssif_state = SSIF_GETTING_FLAGS;
 381         ipmi_ssif_unlock_cond(ssif_info, flags);
 382
 383         mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
 384         mb[1] = IPMI_GET_MSG_FLAGS_CMD;
 385         if (start_send(ssif_info, mb, 2) != 0)
 386                 ssif_info->ssif_state = SSIF_NORMAL;
 387 }
 388
 389 static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
 390                              struct ipmi_smi_msg *msg)
 391 {
 392         if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
 393                 unsigned long oflags;
 394
 395                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 396                 ssif_info->curr_msg = NULL;
 397                 ssif_info->ssif_state = SSIF_NORMAL;
 398                 ipmi_ssif_unlock_cond(ssif_info, flags);
 399                 ipmi_free_smi_msg(msg);
 400         }
 401 }
 402
 403 static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 404 {
 405         struct ipmi_smi_msg *msg;
 406
 407         ssif_info->req_events = false;
 408
 409         msg = ipmi_alloc_smi_msg();
 410         if (!msg) {
 411                 ssif_info->ssif_state = SSIF_NORMAL;
 412                 ipmi_ssif_unlock_cond(ssif_info, flags);
 413                 return;
 414         }
 415
 416         ssif_info->curr_msg = msg;
 417         ssif_info->ssif_state = SSIF_GETTING_EVENTS;
 418         ipmi_ssif_unlock_cond(ssif_info, flags);
 419
 420         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 421         msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
 422         msg->data_size = 2;
 423
 424         check_start_send(ssif_info, flags, msg);
 425 }
 426
 427 static void start_recv_msg_fetch(struct ssif_info *ssif_info,
 428                                  unsigned long *flags)
 429 {
 430         struct ipmi_smi_msg *msg;
 431
 432         msg = ipmi_alloc_smi_msg();
 433         if (!msg) {
 434                 ssif_info->ssif_state = SSIF_NORMAL;
 435                 ipmi_ssif_unlock_cond(ssif_info, flags);
 436                 return;
 437         }
 438
 439         ssif_info->curr_msg = msg;
 440         ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
 441         ipmi_ssif_unlock_cond(ssif_info, flags);
 442
 443         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 444         msg->data[1] = IPMI_GET_MSG_CMD;
 445         msg->data_size = 2;
 446
 447         check_start_send(ssif_info, flags, msg);
 448 }
 449
 450 /*
 451  * Must be called with the message lock held.  This will release the
 452  * message lock.  Note that the caller will check SSIF_IDLE and start a
 453  * new operation, so there is no need to check for new messages to
 454  * start in here.
 455  */
 456 static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
 457 {
 458         if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
 459                 ipmi_smi_t intf = ssif_info->intf;
 460                 /* Watchdog pre-timeout */
 461                 ssif_inc_stat(ssif_info, watchdog_pretimeouts);
 462                 start_clear_flags(ssif_info, flags);
 463                 if (intf)
 464                         ipmi_smi_watchdog_pretimeout(intf);
 465         } else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
 466                 /* Messages available. */
 467                 start_recv_msg_fetch(ssif_info, flags);
 468         else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
 469                 /* Events available. */
 470                 start_event_fetch(ssif_info, flags);
 471         else {
 472                 ssif_info->ssif_state = SSIF_NORMAL;
 473                 ipmi_ssif_unlock_cond(ssif_info, flags);
 474         }
 475 }
 476
 477 static int ipmi_ssif_thread(void *data)
 478 {
 479         struct ssif_info *ssif_info = data;
 480
 481         while (!kthread_should_stop()) {
 482                 int result;
 483
 484                 /* Wait for something to do */
 485                 result = wait_for_completion_interruptible(
 486                                                 &ssif_info->wake_thread);
 487                 if (ssif_info->stopping)
 488                         break;
 489                 if (result == -ERESTARTSYS)
 490                         continue;
 491                 init_completion(&ssif_info->wake_thread);
 492
 493                 if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
 494                         result = i2c_smbus_write_block_data(
 495                                 ssif_info->client, ssif_info->i2c_command,
 496                                 ssif_info->i2c_data[0],
 497                                 ssif_info->i2c_data + 1);
 498                         ssif_info->done_handler(ssif_info, result, NULL, 0);
 499                 } else {
 500                         result = i2c_smbus_read_block_data(
 501                                 ssif_info->client, ssif_info->i2c_command,
 502                                 ssif_info->i2c_data);
 503                         if (result < 0)
 504                                 ssif_info->done_handler(ssif_info, result,
 505                                                         NULL, 0);
 506                         else
 507                                 ssif_info->done_handler(ssif_info, 0,
 508                                                         ssif_info->i2c_data,
 509                                                         result);
 510                 }
 511         }
 512
 513         return 0;
 514 }
 515
 516 static int ssif_i2c_send(struct ssif_info *ssif_info,
 517                         ssif_i2c_done handler,
 518                         int read_write, int command,
 519                         unsigned char *data, unsigned int size)
 520 {
 521         ssif_info->done_handler = handler;
 522
 523         ssif_info->i2c_read_write = read_write;
 524         ssif_info->i2c_command = command;
 525         ssif_info->i2c_data = data;
 526         ssif_info->i2c_size = size;
 527         complete(&ssif_info->wake_thread);
 528         return 0;
 529 }
 530
 531
 532 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 533                              unsigned char *data, unsigned int len);
 534
 535 static void start_get(struct ssif_info *ssif_info)
 536 {
 537         int rv;
 538
 539         ssif_info->rtc_us_timer = 0;
 540         ssif_info->multi_pos = 0;
 541
 542         rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 543                           SSIF_IPMI_RESPONSE,
 544                           ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 545         if (rv < 0) {
 546                 /* request failed, just return the error. */
 547                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 548                         pr_info("Error from i2c_non_blocking_op(5)\n");
 549
 550                 msg_done_handler(ssif_info, -EIO, NULL, 0);
 551         }
 552 }
 553
 554 static void retry_timeout(unsigned long data)
 555 {
 556         struct ssif_info *ssif_info = (void *) data;
 557         unsigned long oflags, *flags;
 558         bool waiting;
 559
 560         if (ssif_info->stopping)
 561                 return;
 562
 563         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 564         waiting = ssif_info->waiting_alert;
 565         ssif_info->waiting_alert = false;
 566         ipmi_ssif_unlock_cond(ssif_info, flags);
 567
 568         if (waiting)
 569                 start_get(ssif_info);
 570 }
 571
 572
 573 static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
 574                        unsigned int data)
 575 {
 576         struct ssif_info *ssif_info = i2c_get_clientdata(client);
 577         unsigned long oflags, *flags;
 578         bool do_get = false;
 579
 580         if (type != I2C_PROTOCOL_SMBUS_ALERT)
 581                 return;
 582
 583         ssif_inc_stat(ssif_info, alerts);
 584
 585         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 586         if (ssif_info->waiting_alert) {
 587                 ssif_info->waiting_alert = false;
 588                 del_timer(&ssif_info->retry_timer);
 589                 do_get = true;
 590         } else if (ssif_info->curr_msg) {
 591                 ssif_info->got_alert = true;
 592         }
 593         ipmi_ssif_unlock_cond(ssif_info, flags);
 594         if (do_get)
 595                 start_get(ssif_info);
 596 }
 597
 598 static int start_resend(struct ssif_info *ssif_info);
 599
 600 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 601                              unsigned char *data, unsigned int len)
 602 {
 603         struct ipmi_smi_msg *msg;
 604         unsigned long oflags, *flags;
 605         int rv;
 606
 607         /*
 608          * We are single-threaded here, so no need for a lock until we
 609          * start messing with driver states or the queues.
 610          */
 611
 612         if (result < 0) {
 613                 ssif_info->retries_left--;
 614                 if (ssif_info->retries_left > 0) {
 615                         ssif_inc_stat(ssif_info, receive_retries);
 616
 617                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 618                         ssif_info->waiting_alert = true;
 619                         ssif_info->rtc_us_timer = SSIF_MSG_USEC;
 620                         if (!ssif_info->stopping)
 621                                 mod_timer(&ssif_info->retry_timer,
 622                                           jiffies + SSIF_MSG_JIFFIES);
 623                         ipmi_ssif_unlock_cond(ssif_info, flags);
 624                         return;
 625                 }
 626
 627                 ssif_inc_stat(ssif_info, receive_errors);
 628
 629                 if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 630                         pr_info("Error in msg_done_handler: %d\n", result);
 631                 len = 0;
 632                 goto continue_op;
 633         }
 634
 635         if ((len > 1) && (ssif_info->multi_pos == 0)
 636                                 && (data[0] == 0x00) && (data[1] == 0x01)) {
 637                 /* Start of multi-part read.  Start the next transaction. */
 638                 int i;
 639
 640                 ssif_inc_stat(ssif_info, received_message_parts);
 641
 642                 /* Remove the multi-part read marker. */
 643                 len -= 2;
 644                 data += 2;
 645                 for (i = 0; i < len; i++)
 646                         ssif_info->data[i] = data[i];
 647                 ssif_info->multi_len = len;
 648                 ssif_info->multi_pos = 1;
 649
 650                 rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 651                                   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 652                                   ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 653                 if (rv < 0) {
 654                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 655                                 pr_info("Error from i2c_non_blocking_op(1)\n");
 656
 657                         result = -EIO;
 658                 } else
 659                         return;
 660         } else if (ssif_info->multi_pos) {
 661                 /* Middle of multi-part read.  Start the next transaction. */
 662                 int i;
 663                 unsigned char blocknum;
 664
 665                 if (len == 0) {
 666                         result = -EIO;
 667                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 668                                 pr_info(PFX "Middle message with no data\n");
 669
 670                         goto continue_op;
 671                 }
 672
 673                 blocknum = data[0];
 674                 len--;
 675                 data++;
 676
 677                 if (blocknum != 0xff && len != 31) {
 678                     /* All blocks but the last must have 31 data bytes. */
 679                         result = -EIO;
 680                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 681                                 pr_info("Received middle message <31\n");
 682
 683                         goto continue_op;
 684                 }
 685
 686                 if (ssif_info->multi_len + len > IPMI_MAX_MSG_LENGTH) {
 687                         /* Received message too big, abort the operation. */
 688                         result = -E2BIG;
 689                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 690                                 pr_info("Received message too big\n");
 691
 692                         goto continue_op;
 693                 }
 694
 695                 for (i = 0; i < len; i++)
 696                         ssif_info->data[i + ssif_info->multi_len] = data[i];
 697                 ssif_info->multi_len += len;
 698                 if (blocknum == 0xff) {
 699                         /* End of read */
 700                         len = ssif_info->multi_len;
 701                         data = ssif_info->data;
 702                 } else if (blocknum + 1 != ssif_info->multi_pos) {
 703                         /*
 704                          * Out of sequence block, just abort.  Block
 705                          * numbers start at zero for the second block,
 706                          * but multi_pos starts at one, so the +1.
 707                          */
 708                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 709                                 dev_dbg(&ssif_info->client->dev,
 710                                         "Received message out of sequence, expected %u, got %u\n",
 711                                         ssif_info->multi_pos - 1, blocknum);
 712                         result = -EIO;
 713                 } else {
 714                         ssif_inc_stat(ssif_info, received_message_parts);
 715
 716                         ssif_info->multi_pos++;
 717
 718                         rv = ssif_i2c_send(ssif_info, msg_done_handler,
 719                                            I2C_SMBUS_READ,
 720                                            SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 721                                            ssif_info->recv,
 722                                            I2C_SMBUS_BLOCK_DATA);
 723                         if (rv < 0) {
 724                                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 725                                         pr_info(PFX
 726                                                 "Error from ssif_i2c_send\n");
 727
 728                                 result = -EIO;
 729                         } else
 730                                 return;
 731                 }
 732         }
 733
 734  continue_op:
 735         if (result < 0) {
 736                 ssif_inc_stat(ssif_info, receive_errors);
 737         } else {
 738                 ssif_inc_stat(ssif_info, received_messages);
 739                 ssif_inc_stat(ssif_info, received_message_parts);
 740         }
 741
 742         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 743                 pr_info(PFX "DONE 1: state = %d, result=%d.\n",
 744                         ssif_info->ssif_state, result);
 745
 746         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 747         msg = ssif_info->curr_msg;
 748         if (msg) {
 749                 if (data) {
 750                         if (len > IPMI_MAX_MSG_LENGTH)
 751                                 len = IPMI_MAX_MSG_LENGTH;
 752                         memcpy(msg->rsp, data, len);
 753                 } else {
 754                         len = 0;
 755                 }
 756                 msg->rsp_size = len;
 757                 ssif_info->curr_msg = NULL;
 758         }
 759
 760         switch (ssif_info->ssif_state) {
 761         case SSIF_NORMAL:
 762                 ipmi_ssif_unlock_cond(ssif_info, flags);
 763                 if (!msg)
 764                         break;
 765
 766                 if (result < 0)
 767                         return_hosed_msg(ssif_info, msg);
 768                 else
 769                         deliver_recv_msg(ssif_info, msg);
 770                 break;
 771
 772         case SSIF_GETTING_FLAGS:
 773                 /* We got the flags from the SSIF, now handle them. */
 774                 if ((result < 0) || (len < 4) || (data[2] != 0)) {
 775                         /*
 776                          * Error fetching flags, or invalid length,
 777                          * just give up for now.
 778                          */
 779                         ssif_info->ssif_state = SSIF_NORMAL;
 780                         ipmi_ssif_unlock_cond(ssif_info, flags);
 781                         pr_warn(PFX "Error getting flags: %d %d, %x\n",
 782                                result, len, (len >= 3) ? data[2] : 0);
 783                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 784                            || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
 785                         /*
 786                          * Don't abort here, maybe it was a queued
 787                          * response to a previous command.
 788                          */
 789                         ipmi_ssif_unlock_cond(ssif_info, flags);
 790                         pr_warn(PFX "Invalid response getting flags: %x %x\n",
 791                                 data[0], data[1]);
 792                 } else {
 793                         ssif_inc_stat(ssif_info, flag_fetches);
 794                         ssif_info->msg_flags = data[3];
 795                         handle_flags(ssif_info, flags);
 796                 }
 797                 break;
 798
 799         case SSIF_CLEARING_FLAGS:
 800                 /* We cleared the flags. */
 801                 if ((result < 0) || (len < 3) || (data[2] != 0)) {
 802                         /* Error clearing flags */
 803                         pr_warn(PFX "Error clearing flags: %d %d, %x\n",
 804                                result, len, (len >= 3) ? data[2] : 0);
 805                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 806                            || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
 807                         pr_warn(PFX "Invalid response clearing flags: %x %x\n",
 808                                 data[0], data[1]);
 809                 }
 810                 ssif_info->ssif_state = SSIF_NORMAL;
 811                 ipmi_ssif_unlock_cond(ssif_info, flags);
 812                 break;
 813
 814         case SSIF_GETTING_EVENTS:
 815                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 816                         /* Error getting event, probably done. */
 817                         msg->done(msg);
 818
 819                         /* Take off the event flag. */
 820                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 821                         handle_flags(ssif_info, flags);
 822                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 823                            || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
 824                         pr_warn(PFX "Invalid response getting events: %x %x\n",
 825                                 msg->rsp[0], msg->rsp[1]);
 826                         msg->done(msg);
 827                         /* Take off the event flag. */
 828                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 829                         handle_flags(ssif_info, flags);
 830                 } else {
 831                         handle_flags(ssif_info, flags);
 832                         ssif_inc_stat(ssif_info, events);
 833                         deliver_recv_msg(ssif_info, msg);
 834                 }
 835                 break;
 836
 837         case SSIF_GETTING_MESSAGES:
 838                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 839                         /* Error getting event, probably done. */
 840                         msg->done(msg);
 841
 842                         /* Take off the msg flag. */
 843                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 844                         handle_flags(ssif_info, flags);
 845                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 846                            || msg->rsp[1] != IPMI_GET_MSG_CMD) {
 847                         pr_warn(PFX "Invalid response clearing flags: %x %x\n",
 848                                 msg->rsp[0], msg->rsp[1]);
 849                         msg->done(msg);
 850
 851                         /* Take off the msg flag. */
 852                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 853                         handle_flags(ssif_info, flags);
 854                 } else {
 855                         ssif_inc_stat(ssif_info, incoming_messages);
 856                         handle_flags(ssif_info, flags);
 857                         deliver_recv_msg(ssif_info, msg);
 858                 }
 859                 break;
 860         }
 861
 862         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 863         if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
 864                 if (ssif_info->req_events)
 865                         start_event_fetch(ssif_info, flags);
 866                 else if (ssif_info->req_flags)
 867                         start_flag_fetch(ssif_info, flags);
 868                 else
 869                         start_next_msg(ssif_info, flags);
 870         } else
 871                 ipmi_ssif_unlock_cond(ssif_info, flags);
 872
 873         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 874                 pr_info(PFX "DONE 2: state = %d.\n", ssif_info->ssif_state);
 875 }
 876
 877 static void msg_written_handler(struct ssif_info *ssif_info, int result,
 878                                 unsigned char *data, unsigned int len)
 879 {
 880         int rv;
 881
 882         /* We are single-threaded here, so no need for a lock. */
 883         if (result < 0) {
 884                 ssif_info->retries_left--;
 885                 if (ssif_info->retries_left > 0) {
 886                         if (!start_resend(ssif_info)) {
 887                                 ssif_inc_stat(ssif_info, send_retries);
 888                                 return;
 889                         }
 890                         /* request failed, just return the error. */
 891                         ssif_inc_stat(ssif_info, send_errors);
 892
 893                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 894                                 pr_info(PFX
 895                                         "Out of retries in msg_written_handler\n");
 896                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 897                         return;
 898                 }
 899
 900                 ssif_inc_stat(ssif_info, send_errors);
 901
 902                 /*
 903                  * Got an error on transmit, let the done routine
 904                  * handle it.
 905                  */
 906                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 907                         pr_info("Error in msg_written_handler: %d\n", result);
 908
 909                 msg_done_handler(ssif_info, result, NULL, 0);
 910                 return;
 911         }
 912
 913         if (ssif_info->multi_data) {
 914                 /*
 915                  * In the middle of a multi-data write.  See the comment
 916                  * in the SSIF_MULTI_n_PART case in the probe function
 917                  * for details on the intricacies of this.
 918                  */
 919                 int left;
 920                 unsigned char *data_to_send;
 921
 922                 ssif_inc_stat(ssif_info, sent_messages_parts);
 923
 924                 left = ssif_info->multi_len - ssif_info->multi_pos;
 925                 if (left > 32)
 926                         left = 32;
 927                 /* Length byte. */
 928                 ssif_info->multi_data[ssif_info->multi_pos] = left;
 929                 data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
 930                 ssif_info->multi_pos += left;
 931                 if (left < 32)
 932                         /*
 933                          * Write is finished.  Note that we must end
 934                          * with a write of less than 32 bytes to
 935                          * complete the transaction, even if it is
 936                          * zero bytes.
 937                          */
 938                         ssif_info->multi_data = NULL;
 939
 940                 rv = ssif_i2c_send(ssif_info, msg_written_handler,
 941                                   I2C_SMBUS_WRITE,
 942                                   SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
 943                                   data_to_send,
 944                                   I2C_SMBUS_BLOCK_DATA);
 945                 if (rv < 0) {
 946                         /* request failed, just return the error. */
 947                         ssif_inc_stat(ssif_info, send_errors);
 948
 949                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 950                                 pr_info("Error from i2c_non_blocking_op(3)\n");
 951                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 952                 }
 953         } else {
 954                 /* Ready to request the result. */
 955                 unsigned long oflags, *flags;
 956
 957                 ssif_inc_stat(ssif_info, sent_messages);
 958                 ssif_inc_stat(ssif_info, sent_messages_parts);
 959
 960                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 961                 if (ssif_info->got_alert) {
 962                         /* The result is already ready, just start it. */
 963                         ssif_info->got_alert = false;
 964                         ipmi_ssif_unlock_cond(ssif_info, flags);
 965                         start_get(ssif_info);
 966                 } else {
 967                         /* Wait a jiffie then request the next message */
 968                         ssif_info->waiting_alert = true;
 969                         ssif_info->retries_left = SSIF_RECV_RETRIES;
 970                         ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
 971                         if (!ssif_info->stopping)
 972                                 mod_timer(&ssif_info->retry_timer,
 973                                           jiffies + SSIF_MSG_PART_JIFFIES);
 974                         ipmi_ssif_unlock_cond(ssif_info, flags);
 975                 }
 976         }
 977 }
 978
 979 static int start_resend(struct ssif_info *ssif_info)
 980 {
 981         int rv;
 982         int command;
 983
 984         ssif_info->got_alert = false;
 985
 986         if (ssif_info->data_len > 32) {
 987                 command = SSIF_IPMI_MULTI_PART_REQUEST_START;
 988                 ssif_info->multi_data = ssif_info->data;
 989                 ssif_info->multi_len = ssif_info->data_len;
 990                 /*
 991                  * Subtle thing, this is 32, not 33, because we will
 992                  * overwrite the thing at position 32 (which was just
 993                  * transmitted) with the new length.
 994                  */
 995                 ssif_info->multi_pos = 32;
 996                 ssif_info->data[0] = 32;
 997         } else {
 998                 ssif_info->multi_data = NULL;
 999                 command = SSIF_IPMI_REQUEST;
1000                 ssif_info->data[0] = ssif_info->data_len;
1001         }
1002
1003         rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
1004                           command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
1005         if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
1006                 pr_info("Error from i2c_non_blocking_op(4)\n");
1007         return rv;
1008 }
1009
1010 static int start_send(struct ssif_info *ssif_info,
1011                       unsigned char   *data,
1012                       unsigned int    len)
1013 {
1014         if (len > IPMI_MAX_MSG_LENGTH)
1015                 return -E2BIG;
1016         if (len > ssif_info->max_xmit_msg_size)
1017                 return -E2BIG;
1018
1019         ssif_info->retries_left = SSIF_SEND_RETRIES;
1020         memcpy(ssif_info->data + 1, data, len);
1021         ssif_info->data_len = len;
1022         return start_resend(ssif_info);
1023 }
1024
1025 /* Must be called with the message lock held. */
1026 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
1027 {
1028         struct ipmi_smi_msg *msg;
1029         unsigned long oflags;
1030
1031  restart:
1032         if (!SSIF_IDLE(ssif_info)) {
1033                 ipmi_ssif_unlock_cond(ssif_info, flags);
1034                 return;
1035         }
1036
1037         if (!ssif_info->waiting_msg) {
1038                 ssif_info->curr_msg = NULL;
1039                 ipmi_ssif_unlock_cond(ssif_info, flags);
1040         } else {
1041                 int rv;
1042
1043                 ssif_info->curr_msg = ssif_info->waiting_msg;
1044                 ssif_info->waiting_msg = NULL;
1045                 ipmi_ssif_unlock_cond(ssif_info, flags);
1046                 rv = start_send(ssif_info,
1047                                 ssif_info->curr_msg->data,
1048                                 ssif_info->curr_msg->data_size);
1049                 if (rv) {
1050                         msg = ssif_info->curr_msg;
1051                         ssif_info->curr_msg = NULL;
1052                         return_hosed_msg(ssif_info, msg);
1053                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1054                         goto restart;
1055                 }
1056         }
1057 }
1058
1059 static void sender(void                *send_info,
1060                    struct ipmi_smi_msg *msg)
1061 {
1062         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1063         unsigned long oflags, *flags;
1064
1065         BUG_ON(ssif_info->waiting_msg);
1066         ssif_info->waiting_msg = msg;
1067
1068         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1069         start_next_msg(ssif_info, flags);
1070
1071         if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1072                 struct timespec64 t;
1073
1074                 ktime_get_real_ts64(&t);
1075                 pr_info("**Enqueue %02x %02x: %lld.%6.6ld\n",
1076                        msg->data[0], msg->data[1],
1077                        (long long) t.tv_sec, (long) t.tv_nsec / NSEC_PER_USEC);
1078         }
1079 }
1080
1081 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1082 {
1083         struct ssif_info *ssif_info = send_info;
1084
1085         data->addr_src = ssif_info->addr_source;
1086         data->dev = &ssif_info->client->dev;
1087         data->addr_info = ssif_info->addr_info;
1088         get_device(data->dev);
1089
1090         return 0;
1091 }
1092
1093 /*
1094  * Instead of having our own timer to periodically check the message
1095  * flags, we let the message handler drive us.
1096  */
1097 static void request_events(void *send_info)
1098 {
1099         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1100         unsigned long oflags, *flags;
1101
1102         if (!ssif_info->has_event_buffer)
1103                 return;
1104
1105         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1106         /*
1107          * Request flags first, not events, because the lower layer
1108          * doesn't have a way to send an attention.  But make sure
1109          * event checking still happens.
1110          */
1111         ssif_info->req_events = true;
1112         if (SSIF_IDLE(ssif_info))
1113                 start_flag_fetch(ssif_info, flags);
1114         else {
1115                 ssif_info->req_flags = true;
1116                 ipmi_ssif_unlock_cond(ssif_info, flags);
1117         }
1118 }
1119
1120 static int inc_usecount(void *send_info)
1121 {
1122         struct ssif_info *ssif_info = send_info;
1123
1124         if (!i2c_get_adapter(ssif_info->client->adapter->nr))
1125                 return -ENODEV;
1126
1127         i2c_use_client(ssif_info->client);
1128         return 0;
1129 }
1130
1131 static void dec_usecount(void *send_info)
1132 {
1133         struct ssif_info *ssif_info = send_info;
1134
1135         i2c_release_client(ssif_info->client);
1136         i2c_put_adapter(ssif_info->client->adapter);
1137 }
1138
1139 static int ssif_start_processing(void *send_info,
1140                                  ipmi_smi_t intf)
1141 {
1142         struct ssif_info *ssif_info = send_info;
1143
1144         ssif_info->intf = intf;
1145
1146         return 0;
1147 }
1148
1149 #define MAX_SSIF_BMCS 4
1150
1151 static unsigned short addr[MAX_SSIF_BMCS];
1152 static int num_addrs;
1153 module_param_array(addr, ushort, &num_addrs, 0);
1154 MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1155
1156 static char *adapter_name[MAX_SSIF_BMCS];
1157 static int num_adapter_names;
1158 module_param_array(adapter_name, charp, &num_adapter_names, 0);
1159 MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1160
1161 static int slave_addrs[MAX_SSIF_BMCS];
1162 static int num_slave_addrs;
1163 module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1164 MODULE_PARM_DESC(slave_addrs,
1165                  "The default IPMB slave address for the controller.");
1166
1167 static bool alerts_broken;
1168 module_param(alerts_broken, bool, 0);
1169 MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1170
1171 /*
1172  * Bit 0 enables message debugging, bit 1 enables state debugging, and
1173  * bit 2 enables timing debugging.  This is an array indexed by
1174  * interface number"
1175  */
1176 static int dbg[MAX_SSIF_BMCS];
1177 static int num_dbg;
1178 module_param_array(dbg, int, &num_dbg, 0);
1179 MODULE_PARM_DESC(dbg, "Turn on debugging.");
1180
1181 static bool ssif_dbg_probe;
1182 module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1183 MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1184
1185 static int use_thread;
1186 module_param(use_thread, int, 0);
1187 MODULE_PARM_DESC(use_thread, "Use the thread interface.");
1188
1189 static bool ssif_tryacpi = true;
1190 module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1191 MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1192
1193 static bool ssif_trydmi = true;
1194 module_param_named(trydmi, ssif_trydmi, bool, 0);
1195 MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1196
1197 static DEFINE_MUTEX(ssif_infos_mutex);
1198 static LIST_HEAD(ssif_infos);
1199
1200 static int ssif_remove(struct i2c_client *client)
1201 {
1202         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1203         int rv;
1204
1205         if (!ssif_info)
1206                 return 0;
1207
1208         /*
1209          * After this point, we won't deliver anything asychronously
1210          * to the message handler.  We can unregister ourself.
1211          */
1212         rv = ipmi_unregister_smi(ssif_info->intf);
1213         if (rv) {
1214                 pr_err(PFX "Unable to unregister device: errno=%d\n", rv);
1215                 return rv;
1216         }
1217         ssif_info->intf = NULL;
1218
1219         /* make sure the driver is not looking for flags any more. */
1220         while (ssif_info->ssif_state != SSIF_NORMAL)
1221                 schedule_timeout(1);
1222
1223         ssif_info->stopping = true;
1224         del_timer_sync(&ssif_info->retry_timer);
1225         if (ssif_info->thread) {
1226                 complete(&ssif_info->wake_thread);
1227                 kthread_stop(ssif_info->thread);
1228         }
1229
1230         /*
1231          * No message can be outstanding now, we have removed the
1232          * upper layer and it permitted us to do so.
1233          */
1234         kfree(ssif_info);
1235         return 0;
1236 }
1237
1238 static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1239                   int *resp_len, unsigned char *resp)
1240 {
1241         int retry_cnt;
1242         int ret;
1243
1244         retry_cnt = SSIF_SEND_RETRIES;
1245  retry1:
1246         ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1247         if (ret) {
1248                 retry_cnt--;
1249                 if (retry_cnt > 0)
1250                         goto retry1;
1251                 return -ENODEV;
1252         }
1253
1254         ret = -ENODEV;
1255         retry_cnt = SSIF_RECV_RETRIES;
1256         while (retry_cnt > 0) {
1257                 ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1258                                                 resp);
1259                 if (ret > 0)
1260                         break;
1261                 msleep(SSIF_MSG_MSEC);
1262                 retry_cnt--;
1263                 if (retry_cnt <= 0)
1264                         break;
1265         }
1266
1267         if (ret > 0) {
1268                 /* Validate that the response is correct. */
1269                 if (ret < 3 ||
1270                     (resp[0] != (msg[0] | (1 << 2))) ||
1271                     (resp[1] != msg[1]))
1272                         ret = -EINVAL;
1273                 else {
1274                         *resp_len = ret;
1275                         ret = 0;
1276                 }
1277         }
1278
1279         return ret;
1280 }
1281
1282 static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1283 {
1284         unsigned char *resp;
1285         unsigned char msg[3];
1286         int           rv;
1287         int           len;
1288
1289         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1290         if (!resp)
1291                 return -ENOMEM;
1292
1293         /* Do a Get Device ID command, since it is required. */
1294         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1295         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1296         rv = do_cmd(client, 2, msg, &len, resp);
1297         if (rv)
1298                 rv = -ENODEV;
1299         else
1300                 strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1301         kfree(resp);
1302         return rv;
1303 }
1304
1305 static int smi_type_proc_show(struct seq_file *m, void *v)
1306 {
1307         seq_puts(m, "ssif\n");
1308
1309         return 0;
1310 }
1311
1312 static int smi_type_proc_open(struct inode *inode, struct file *file)
1313 {
1314         return single_open(file, smi_type_proc_show, inode->i_private);
1315 }
1316
1317 static const struct file_operations smi_type_proc_ops = {
1318         .open           = smi_type_proc_open,
1319         .read           = seq_read,
1320         .llseek         = seq_lseek,
1321         .release        = single_release,
1322 };
1323
1324 static int smi_stats_proc_show(struct seq_file *m, void *v)
1325 {
1326         struct ssif_info *ssif_info = m->private;
1327
1328         seq_printf(m, "sent_messages:          %u\n",
1329                    ssif_get_stat(ssif_info, sent_messages));
1330         seq_printf(m, "sent_messages_parts:    %u\n",
1331                    ssif_get_stat(ssif_info, sent_messages_parts));
1332         seq_printf(m, "send_retries:           %u\n",
1333                    ssif_get_stat(ssif_info, send_retries));
1334         seq_printf(m, "send_errors:            %u\n",
1335                    ssif_get_stat(ssif_info, send_errors));
1336         seq_printf(m, "received_messages:      %u\n",
1337                    ssif_get_stat(ssif_info, received_messages));
1338         seq_printf(m, "received_message_parts: %u\n",
1339                    ssif_get_stat(ssif_info, received_message_parts));
1340         seq_printf(m, "receive_retries:        %u\n",
1341                    ssif_get_stat(ssif_info, receive_retries));
1342         seq_printf(m, "receive_errors:         %u\n",
1343                    ssif_get_stat(ssif_info, receive_errors));
1344         seq_printf(m, "flag_fetches:           %u\n",
1345                    ssif_get_stat(ssif_info, flag_fetches));
1346         seq_printf(m, "hosed:                  %u\n",
1347                    ssif_get_stat(ssif_info, hosed));
1348         seq_printf(m, "events:                 %u\n",
1349                    ssif_get_stat(ssif_info, events));
1350         seq_printf(m, "watchdog_pretimeouts:   %u\n",
1351                    ssif_get_stat(ssif_info, watchdog_pretimeouts));
1352         seq_printf(m, "alerts:                 %u\n",
1353                    ssif_get_stat(ssif_info, alerts));
1354         return 0;
1355 }
1356
1357 static int smi_stats_proc_open(struct inode *inode, struct file *file)
1358 {
1359         return single_open(file, smi_stats_proc_show, PDE_DATA(inode));
1360 }
1361
1362 static const struct file_operations smi_stats_proc_ops = {
1363         .open           = smi_stats_proc_open,
1364         .read           = seq_read,
1365         .llseek         = seq_lseek,
1366         .release        = single_release,
1367 };
1368
1369 static int strcmp_nospace(char *s1, char *s2)
1370 {
1371         while (*s1 && *s2) {
1372                 while (isspace(*s1))
1373                         s1++;
1374                 while (isspace(*s2))
1375                         s2++;
1376                 if (*s1 > *s2)
1377                         return 1;
1378                 if (*s1 < *s2)
1379                         return -1;
1380                 s1++;
1381                 s2++;
1382         }
1383         return 0;
1384 }
1385
1386 static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1387                                              char *adapter_name,
1388                                              bool match_null_name)
1389 {
1390         struct ssif_addr_info *info, *found = NULL;
1391
1392 restart:
1393         list_for_each_entry(info, &ssif_infos, link) {
1394                 if (info->binfo.addr == addr) {
1395                         if (info->adapter_name || adapter_name) {
1396                                 if (!info->adapter_name != !adapter_name) {
1397                                         /* One is NULL and one is not */
1398                                         continue;
1399                                 }
1400                                 if (adapter_name &&
1401                                     strcmp_nospace(info->adapter_name,
1402                                                    adapter_name))
1403                                         /* Names do not match */
1404                                         continue;
1405                         }
1406                         found = info;
1407                         break;
1408                 }
1409         }
1410
1411         if (!found && match_null_name) {
1412                 /* Try to get an exact match first, then try with a NULL name */
1413                 adapter_name = NULL;
1414                 match_null_name = false;
1415                 goto restart;
1416         }
1417
1418         return found;
1419 }
1420
1421 static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1422 {
1423 #ifdef CONFIG_ACPI
1424         acpi_handle acpi_handle;
1425
1426         acpi_handle = ACPI_HANDLE(dev);
1427         if (acpi_handle) {
1428                 ssif_info->addr_source = SI_ACPI;
1429                 ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1430                 return true;
1431         }
1432 #endif
1433         return false;
1434 }
1435
1436 /*
1437  * Global enables we care about.
1438  */
1439 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1440                              IPMI_BMC_EVT_MSG_INTR)
1441
1442 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1443 {
1444         unsigned char     msg[3];
1445         unsigned char     *resp;
1446         struct ssif_info   *ssif_info;
1447         int               rv = 0;
1448         int               len;
1449         int               i;
1450         u8                slave_addr = 0;
1451         struct ssif_addr_info *addr_info = NULL;
1452
1453
1454         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1455         if (!resp)
1456                 return -ENOMEM;
1457
1458         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1459         if (!ssif_info) {
1460                 kfree(resp);
1461                 return -ENOMEM;
1462         }
1463
1464         if (!check_acpi(ssif_info, &client->dev)) {
1465                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1466                                            true);
1467                 if (!addr_info) {
1468                         /* Must have come in through sysfs. */
1469                         ssif_info->addr_source = SI_HOTMOD;
1470                 } else {
1471                         ssif_info->addr_source = addr_info->addr_src;
1472                         ssif_info->ssif_debug = addr_info->debug;
1473                         ssif_info->addr_info = addr_info->addr_info;
1474                         slave_addr = addr_info->slave_addr;
1475                 }
1476         }
1477
1478         pr_info(PFX "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1479                ipmi_addr_src_to_str(ssif_info->addr_source),
1480                client->addr, client->adapter->name, slave_addr);
1481
1482         /*
1483          * Do a Get Device ID command, since it comes back with some
1484          * useful info.
1485          */
1486         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1487         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1488         rv = do_cmd(client, 2, msg, &len, resp);
1489         if (rv)
1490                 goto out;
1491
1492         rv = ipmi_demangle_device_id(resp, len, &ssif_info->device_id);
1493         if (rv)
1494                 goto out;
1495
1496         ssif_info->client = client;
1497         i2c_set_clientdata(client, ssif_info);
1498
1499         /* Now check for system interface capabilities */
1500         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1501         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1502         msg[2] = 0; /* SSIF */
1503         rv = do_cmd(client, 3, msg, &len, resp);
1504         if (!rv && (len >= 3) && (resp[2] == 0)) {
1505                 if (len < 7) {
1506                         if (ssif_dbg_probe)
1507                                 pr_info(PFX "SSIF info too short: %d\n", len);
1508                         goto no_support;
1509                 }
1510
1511                 /* Got a good SSIF response, handle it. */
1512                 ssif_info->max_xmit_msg_size = resp[5];
1513                 ssif_info->max_recv_msg_size = resp[6];
1514                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1515                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1516
1517                 /* Sanitize the data */
1518                 switch (ssif_info->multi_support) {
1519                 case SSIF_NO_MULTI:
1520                         if (ssif_info->max_xmit_msg_size > 32)
1521                                 ssif_info->max_xmit_msg_size = 32;
1522                         if (ssif_info->max_recv_msg_size > 32)
1523                                 ssif_info->max_recv_msg_size = 32;
1524                         break;
1525
1526                 case SSIF_MULTI_2_PART:
1527                         if (ssif_info->max_xmit_msg_size > 63)
1528                                 ssif_info->max_xmit_msg_size = 63;
1529                         if (ssif_info->max_recv_msg_size > 62)
1530                                 ssif_info->max_recv_msg_size = 62;
1531                         break;
1532
1533                 case SSIF_MULTI_n_PART:
1534                         /*
1535                          * The specification is rather confusing at
1536                          * this point, but I think I understand what
1537                          * is meant.  At least I have a workable
1538                          * solution.  With multi-part messages, you
1539                          * cannot send a message that is a multiple of
1540                          * 32-bytes in length, because the start and
1541                          * middle messages are 32-bytes and the end
1542                          * message must be at least one byte.  You
1543                          * can't fudge on an extra byte, that would
1544                          * screw up things like fru data writes.  So
1545                          * we limit the length to 63 bytes.  That way
1546                          * a 32-byte message gets sent as a single
1547                          * part.  A larger message will be a 32-byte
1548                          * start and the next message is always going
1549                          * to be 1-31 bytes in length.  Not ideal, but
1550                          * it should work.
1551                          */
1552                         if (ssif_info->max_xmit_msg_size > 63)
1553                                 ssif_info->max_xmit_msg_size = 63;
1554                         break;
1555
1556                 default:
1557                         /* Data is not sane, just give up. */
1558                         goto no_support;
1559                 }
1560         } else {
1561  no_support:
1562                 /* Assume no multi-part or PEC support */
1563                 pr_info(PFX "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1564                        rv, len, resp[2]);
1565
1566                 ssif_info->max_xmit_msg_size = 32;
1567                 ssif_info->max_recv_msg_size = 32;
1568                 ssif_info->multi_support = SSIF_NO_MULTI;
1569                 ssif_info->supports_pec = 0;
1570         }
1571
1572         /* Make sure the NMI timeout is cleared. */
1573         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1574         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1575         msg[2] = WDT_PRE_TIMEOUT_INT;
1576         rv = do_cmd(client, 3, msg, &len, resp);
1577         if (rv || (len < 3) || (resp[2] != 0))
1578                 pr_warn(PFX "Unable to clear message flags: %d %d %2.2x\n",
1579                         rv, len, resp[2]);
1580
1581         /* Attempt to enable the event buffer. */
1582         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1583         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1584         rv = do_cmd(client, 2, msg, &len, resp);
1585         if (rv || (len < 4) || (resp[2] != 0)) {
1586                 pr_warn(PFX "Error getting global enables: %d %d %2.2x\n",
1587                         rv, len, resp[2]);
1588                 rv = 0; /* Not fatal */
1589                 goto found;
1590         }
1591
1592         ssif_info->global_enables = resp[3];
1593
1594         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1595                 ssif_info->has_event_buffer = true;
1596                 /* buffer is already enabled, nothing to do. */
1597                 goto found;
1598         }
1599
1600         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1601         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1602         msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1603         rv = do_cmd(client, 3, msg, &len, resp);
1604         if (rv || (len < 2)) {
1605                 pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
1606                         rv, len, resp[2]);
1607                 rv = 0; /* Not fatal */
1608                 goto found;
1609         }
1610
1611         if (resp[2] == 0) {
1612                 /* A successful return means the event buffer is supported. */
1613                 ssif_info->has_event_buffer = true;
1614                 ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1615         }
1616
1617         /* Some systems don't behave well if you enable alerts. */
1618         if (alerts_broken)
1619                 goto found;
1620
1621         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1622         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1623         msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1624         rv = do_cmd(client, 3, msg, &len, resp);
1625         if (rv || (len < 2)) {
1626                 pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
1627                         rv, len, resp[2]);
1628                 rv = 0; /* Not fatal */
1629                 goto found;
1630         }
1631
1632         if (resp[2] == 0) {
1633                 /* A successful return means the alert is supported. */
1634                 ssif_info->supports_alert = true;
1635                 ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1636         }
1637
1638  found:
1639         ssif_info->intf_num = atomic_inc_return(&next_intf);
1640
1641         if (ssif_dbg_probe) {
1642                 pr_info("ssif_probe: i2c_probe found device at i2c address %x\n",
1643                         client->addr);
1644         }
1645
1646         spin_lock_init(&ssif_info->lock);
1647         ssif_info->ssif_state = SSIF_NORMAL;
1648         init_timer(&ssif_info->retry_timer);
1649         ssif_info->retry_timer.data = (unsigned long) ssif_info;
1650         ssif_info->retry_timer.function = retry_timeout;
1651
1652         for (i = 0; i < SSIF_NUM_STATS; i++)
1653                 atomic_set(&ssif_info->stats[i], 0);
1654
1655         if (ssif_info->supports_pec)
1656                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1657
1658         ssif_info->handlers.owner = THIS_MODULE;
1659         ssif_info->handlers.start_processing = ssif_start_processing;
1660         ssif_info->handlers.get_smi_info = get_smi_info;
1661         ssif_info->handlers.sender = sender;
1662         ssif_info->handlers.request_events = request_events;
1663         ssif_info->handlers.inc_usecount = inc_usecount;
1664         ssif_info->handlers.dec_usecount = dec_usecount;
1665
1666         {
1667                 unsigned int thread_num;
1668
1669                 thread_num = ((ssif_info->client->adapter->nr << 8) |
1670                               ssif_info->client->addr);
1671                 init_completion(&ssif_info->wake_thread);
1672                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1673                                                "kssif%4.4x", thread_num);
1674                 if (IS_ERR(ssif_info->thread)) {
1675                         rv = PTR_ERR(ssif_info->thread);
1676                         dev_notice(&ssif_info->client->dev,
1677                                    "Could not start kernel thread: error %d\n",
1678                                    rv);
1679                         goto out;
1680                 }
1681         }
1682
1683         rv = ipmi_register_smi(&ssif_info->handlers,
1684                                ssif_info,
1685                                &ssif_info->device_id,
1686                                &ssif_info->client->dev,
1687                                slave_addr);
1688          if (rv) {
1689                 pr_err(PFX "Unable to register device: error %d\n", rv);
1690                 goto out;
1691         }
1692
1693         rv = ipmi_smi_add_proc_entry(ssif_info->intf, "type",
1694                                      &smi_type_proc_ops,
1695                                      ssif_info);
1696         if (rv) {
1697                 pr_err(PFX "Unable to create proc entry: %d\n", rv);
1698                 goto out_err_unreg;
1699         }
1700
1701         rv = ipmi_smi_add_proc_entry(ssif_info->intf, "ssif_stats",
1702                                      &smi_stats_proc_ops,
1703                                      ssif_info);
1704         if (rv) {
1705                 pr_err(PFX "Unable to create proc entry: %d\n", rv);
1706                 goto out_err_unreg;
1707         }
1708
1709  out:
1710         if (rv)
1711                 kfree(ssif_info);
1712         kfree(resp);
1713         return rv;
1714
1715  out_err_unreg:
1716         ipmi_unregister_smi(ssif_info->intf);
1717         goto out;
1718 }
1719
1720 static int ssif_adapter_handler(struct device *adev, void *opaque)
1721 {
1722         struct ssif_addr_info *addr_info = opaque;
1723
1724         if (adev->type != &i2c_adapter_type)
1725                 return 0;
1726
1727         i2c_new_device(to_i2c_adapter(adev), &addr_info->binfo);
1728
1729         if (!addr_info->adapter_name)
1730                 return 1; /* Only try the first I2C adapter by default. */
1731         return 0;
1732 }
1733
1734 static int new_ssif_client(int addr, char *adapter_name,
1735                            int debug, int slave_addr,
1736                            enum ipmi_addr_src addr_src)
1737 {
1738         struct ssif_addr_info *addr_info;
1739         int rv = 0;
1740
1741         mutex_lock(&ssif_infos_mutex);
1742         if (ssif_info_find(addr, adapter_name, false)) {
1743                 rv = -EEXIST;
1744                 goto out_unlock;
1745         }
1746
1747         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1748         if (!addr_info) {
1749                 rv = -ENOMEM;
1750                 goto out_unlock;
1751         }
1752
1753         if (adapter_name) {
1754                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1755                 if (!addr_info->adapter_name) {
1756                         kfree(addr_info);
1757                         rv = -ENOMEM;
1758                         goto out_unlock;
1759                 }
1760         }
1761
1762         strncpy(addr_info->binfo.type, DEVICE_NAME,
1763                 sizeof(addr_info->binfo.type));
1764         addr_info->binfo.addr = addr;
1765         addr_info->binfo.platform_data = addr_info;
1766         addr_info->debug = debug;
1767         addr_info->slave_addr = slave_addr;
1768         addr_info->addr_src = addr_src;
1769
1770         list_add_tail(&addr_info->link, &ssif_infos);
1771
1772         if (initialized)
1773                 i2c_for_each_dev(addr_info, ssif_adapter_handler);
1774         /* Otherwise address list will get it */
1775
1776 out_unlock:
1777         mutex_unlock(&ssif_infos_mutex);
1778         return rv;
1779 }
1780
1781 static void free_ssif_clients(void)
1782 {
1783         struct ssif_addr_info *info, *tmp;
1784
1785         mutex_lock(&ssif_infos_mutex);
1786         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
1787                 list_del(&info->link);
1788                 kfree(info->adapter_name);
1789                 kfree(info);
1790         }
1791         mutex_unlock(&ssif_infos_mutex);
1792 }
1793
1794 static unsigned short *ssif_address_list(void)
1795 {
1796         struct ssif_addr_info *info;
1797         unsigned int count = 0, i;
1798         unsigned short *address_list;
1799
1800         list_for_each_entry(info, &ssif_infos, link)
1801                 count++;
1802
1803         address_list = kzalloc(sizeof(*address_list) * (count + 1), GFP_KERNEL);
1804         if (!address_list)
1805                 return NULL;
1806
1807         i = 0;
1808         list_for_each_entry(info, &ssif_infos, link) {
1809                 unsigned short addr = info->binfo.addr;
1810                 int j;
1811
1812                 for (j = 0; j < i; j++) {
1813                         if (address_list[j] == addr)
1814                                 goto skip_addr;
1815                 }
1816                 address_list[i] = addr;
1817 skip_addr:
1818                 i++;
1819         }
1820         address_list[i] = I2C_CLIENT_END;
1821
1822         return address_list;
1823 }
1824
1825 #ifdef CONFIG_ACPI
1826 static const struct acpi_device_id ssif_acpi_match[] = {
1827         { "IPI0001", 0 },
1828         { },
1829 };
1830 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
1831
1832 /*
1833  * Once we get an ACPI failure, we don't try any more, because we go
1834  * through the tables sequentially.  Once we don't find a table, there
1835  * are no more.
1836  */
1837 static int acpi_failure;
1838
1839 /*
1840  * Defined in the IPMI 2.0 spec.
1841  */
1842 struct SPMITable {
1843         s8      Signature[4];
1844         u32     Length;
1845         u8      Revision;
1846         u8      Checksum;
1847         s8      OEMID[6];
1848         s8      OEMTableID[8];
1849         s8      OEMRevision[4];
1850         s8      CreatorID[4];
1851         s8      CreatorRevision[4];
1852         u8      InterfaceType;
1853         u8      IPMIlegacy;
1854         s16     SpecificationRevision;
1855
1856         /*
1857          * Bit 0 - SCI interrupt supported
1858          * Bit 1 - I/O APIC/SAPIC
1859          */
1860         u8      InterruptType;
1861
1862         /*
1863          * If bit 0 of InterruptType is set, then this is the SCI
1864          * interrupt in the GPEx_STS register.
1865          */
1866         u8      GPE;
1867
1868         s16     Reserved;
1869
1870         /*
1871          * If bit 1 of InterruptType is set, then this is the I/O
1872          * APIC/SAPIC interrupt.
1873          */
1874         u32     GlobalSystemInterrupt;
1875
1876         /* The actual register address. */
1877         struct acpi_generic_address addr;
1878
1879         u8      UID[4];
1880
1881         s8      spmi_id[1]; /* A '\0' terminated array starts here. */
1882 };
1883
1884 static int try_init_spmi(struct SPMITable *spmi)
1885 {
1886         unsigned short myaddr;
1887
1888         if (num_addrs >= MAX_SSIF_BMCS)
1889                 return -1;
1890
1891         if (spmi->IPMIlegacy != 1) {
1892                 pr_warn("IPMI: Bad SPMI legacy: %d\n", spmi->IPMIlegacy);
1893                 return -ENODEV;
1894         }
1895
1896         if (spmi->InterfaceType != 4)
1897                 return -ENODEV;
1898
1899         if (spmi->addr.space_id != ACPI_ADR_SPACE_SMBUS) {
1900                 pr_warn(PFX "Invalid ACPI SSIF I/O Address type: %d\n",
1901                         spmi->addr.space_id);
1902                 return -EIO;
1903         }
1904
1905         myaddr = spmi->addr.address & 0x7f;
1906
1907         return new_ssif_client(myaddr, NULL, 0, 0, SI_SPMI);
1908 }
1909
1910 static void spmi_find_bmc(void)
1911 {
1912         acpi_status      status;
1913         struct SPMITable *spmi;
1914         int              i;
1915
1916         if (acpi_disabled)
1917                 return;
1918
1919         if (acpi_failure)
1920                 return;
1921
1922         for (i = 0; ; i++) {
1923                 status = acpi_get_table(ACPI_SIG_SPMI, i+1,
1924                                         (struct acpi_table_header **)&spmi);
1925                 if (status != AE_OK)
1926                         return;
1927
1928                 try_init_spmi(spmi);
1929         }
1930 }
1931 #else
1932 static void spmi_find_bmc(void) { }
1933 #endif
1934
1935 #ifdef CONFIG_DMI
1936 static int decode_dmi(const struct dmi_device *dmi_dev)
1937 {
1938         struct dmi_header *dm = dmi_dev->device_data;
1939         u8             *data = (u8 *) dm;
1940         u8             len = dm->length;
1941         unsigned short myaddr;
1942         int            slave_addr;
1943
1944         if (num_addrs >= MAX_SSIF_BMCS)
1945                 return -1;
1946
1947         if (len < 9)
1948                 return -1;
1949
1950         if (data[0x04] != 4) /* Not SSIF */
1951                 return -1;
1952
1953         if ((data[8] >> 1) == 0) {
1954                 /*
1955                  * Some broken systems put the I2C address in
1956                  * the slave address field.  We try to
1957                  * accommodate them here.
1958                  */
1959                 myaddr = data[6] >> 1;
1960                 slave_addr = 0;
1961         } else {
1962                 myaddr = data[8] >> 1;
1963                 slave_addr = data[6];
1964         }
1965
1966         return new_ssif_client(myaddr, NULL, 0, 0, SI_SMBIOS);
1967 }
1968
1969 static void dmi_iterator(void)
1970 {
1971         const struct dmi_device *dev = NULL;
1972
1973         while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))
1974                 decode_dmi(dev);
1975 }
1976 #else
1977 static void dmi_iterator(void) { }
1978 #endif
1979
1980 static const struct i2c_device_id ssif_id[] = {
1981         { DEVICE_NAME, 0 },
1982         { }
1983 };
1984 MODULE_DEVICE_TABLE(i2c, ssif_id);
1985
1986 static struct i2c_driver ssif_i2c_driver = {
1987         .class          = I2C_CLASS_HWMON,
1988         .driver         = {
1989                 .name                   = DEVICE_NAME
1990         },
1991         .probe          = ssif_probe,
1992         .remove         = ssif_remove,
1993         .alert          = ssif_alert,
1994         .id_table       = ssif_id,
1995         .detect         = ssif_detect
1996 };
1997
1998 static int init_ipmi_ssif(void)
1999 {
2000         int i;
2001         int rv;
2002
2003         if (initialized)
2004                 return 0;
2005
2006         pr_info("IPMI SSIF Interface driver\n");
2007
2008         /* build list for i2c from addr list */
2009         for (i = 0; i < num_addrs; i++) {
2010                 rv = new_ssif_client(addr[i], adapter_name[i],
2011                                      dbg[i], slave_addrs[i],
2012                                      SI_HARDCODED);
2013                 if (rv)
2014                         pr_err(PFX
2015                                "Couldn't add hardcoded device at addr 0x%x\n",
2016                                addr[i]);
2017         }
2018
2019         if (ssif_tryacpi)
2020                 ssif_i2c_driver.driver.acpi_match_table =
2021                         ACPI_PTR(ssif_acpi_match);
2022         if (ssif_trydmi)
2023                 dmi_iterator();
2024         if (ssif_tryacpi)
2025                 spmi_find_bmc();
2026
2027         ssif_i2c_driver.address_list = ssif_address_list();
2028
2029         rv = i2c_add_driver(&ssif_i2c_driver);
2030         if (!rv)
2031                 initialized = true;
2032
2033         return rv;
2034 }
2035 module_init(init_ipmi_ssif);
2036
2037 static void cleanup_ipmi_ssif(void)
2038 {
2039         if (!initialized)
2040                 return;
2041
2042         initialized = false;
2043
2044         i2c_del_driver(&ssif_i2c_driver);
2045
2046         free_ssif_clients();
2047 }
2048 module_exit(cleanup_ipmi_ssif);
2049
2050 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2051 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2052 MODULE_LICENSE("GPL");