drivers/char/ipmi/ipmi_ssif.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * ipmi_ssif.c
   4  *
   5  * The interface to the IPMI driver for SMBus access to a SMBus
   6  * compliant device.  Called SSIF by the IPMI spec.
   7  *
   8  * Author: Intel Corporation
   9  *         Todd Davis <todd.c.davis@intel.com>
  10  *
  11  * Rewritten by Corey Minyard <minyard@acm.org> to support the
  12  * non-blocking I2C interface, add support for multi-part
  13  * transactions, add PEC support, and general clenaup.
  14  *
  15  * Copyright 2003 Intel Corporation
  16  * Copyright 2005 MontaVista Software
  17  */
  18
  19 /*
  20  * This file holds the "policy" for the interface to the SSIF state
  21  * machine.  It does the configuration, handles timers and interrupts,
  22  * and drives the real SSIF state machine.
  23  */
  24
  25 #define pr_fmt(fmt) "ipmi_ssif: " fmt
  26 #define dev_fmt(fmt) "ipmi_ssif: " fmt
  27
  28 #if defined(MODVERSIONS)
  29 #include <linux/modversions.h>
  30 #endif
  31
  32 #include <linux/module.h>
  33 #include <linux/moduleparam.h>
  34 #include <linux/sched.h>
  35 #include <linux/seq_file.h>
  36 #include <linux/timer.h>
  37 #include <linux/delay.h>
  38 #include <linux/errno.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/slab.h>
  41 #include <linux/list.h>
  42 #include <linux/i2c.h>
  43 #include <linux/ipmi_smi.h>
  44 #include <linux/init.h>
  45 #include <linux/dmi.h>
  46 #include <linux/kthread.h>
  47 #include <linux/acpi.h>
  48 #include <linux/ctype.h>
  49 #include <linux/time64.h>
  50 #include "ipmi_dmi.h"
  51
  52 #define DEVICE_NAME "ipmi_ssif"
  53
  54 #define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD      0x57
  55
  56 #define SSIF_IPMI_REQUEST                       2
  57 #define SSIF_IPMI_MULTI_PART_REQUEST_START      6
  58 #define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE     7
  59 #define SSIF_IPMI_MULTI_PART_REQUEST_END        8
  60 #define SSIF_IPMI_RESPONSE                      3
  61 #define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE    9
  62
  63 /* ssif_debug is a bit-field
  64  *      SSIF_DEBUG_MSG -        commands and their responses
  65  *      SSIF_DEBUG_STATES -     message states
  66  *      SSIF_DEBUG_TIMING -      Measure times between events in the driver
  67  */
  68 #define SSIF_DEBUG_TIMING       4
  69 #define SSIF_DEBUG_STATE        2
  70 #define SSIF_DEBUG_MSG          1
  71 #define SSIF_NODEBUG            0
  72 #define SSIF_DEFAULT_DEBUG      (SSIF_NODEBUG)
  73
  74 /*
  75  * Timer values
  76  */
  77 #define SSIF_MSG_USEC           20000   /* 20ms between message tries. */
  78 #define SSIF_MSG_PART_USEC      5000    /* 5ms for a message part */
  79
  80 /* How many times to we retry sending/receiving the message. */
  81 #define SSIF_SEND_RETRIES       5
  82 #define SSIF_RECV_RETRIES       250
  83
  84 #define SSIF_MSG_MSEC           (SSIF_MSG_USEC / 1000)
  85 #define SSIF_MSG_JIFFIES        ((SSIF_MSG_USEC * 1000) / TICK_NSEC)
  86 #define SSIF_MSG_PART_JIFFIES   ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
  87
  88 /*
  89  * Timeout for the watch, only used for get flag timer.
  90  */
  91 #define SSIF_WATCH_MSG_TIMEOUT          msecs_to_jiffies(10)
  92 #define SSIF_WATCH_WATCHDOG_TIMEOUT     msecs_to_jiffies(250)
  93
  94 enum ssif_intf_state {
  95         SSIF_NORMAL,
  96         SSIF_GETTING_FLAGS,
  97         SSIF_GETTING_EVENTS,
  98         SSIF_CLEARING_FLAGS,
  99         SSIF_GETTING_MESSAGES,
 100         /* FIXME - add watchdog stuff. */
 101 };
 102
 103 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
 104                           && (ssif)->curr_msg == NULL)
 105
 106 /*
 107  * Indexes into stats[] in ssif_info below.
 108  */
 109 enum ssif_stat_indexes {
 110         /* Number of total messages sent. */
 111         SSIF_STAT_sent_messages = 0,
 112
 113         /*
 114          * Number of message parts sent.  Messages may be broken into
 115          * parts if they are long.
 116          */
 117         SSIF_STAT_sent_messages_parts,
 118
 119         /*
 120          * Number of time a message was retried.
 121          */
 122         SSIF_STAT_send_retries,
 123
 124         /*
 125          * Number of times the send of a message failed.
 126          */
 127         SSIF_STAT_send_errors,
 128
 129         /*
 130          * Number of message responses received.
 131          */
 132         SSIF_STAT_received_messages,
 133
 134         /*
 135          * Number of message fragments received.
 136          */
 137         SSIF_STAT_received_message_parts,
 138
 139         /*
 140          * Number of times the receive of a message was retried.
 141          */
 142         SSIF_STAT_receive_retries,
 143
 144         /*
 145          * Number of errors receiving messages.
 146          */
 147         SSIF_STAT_receive_errors,
 148
 149         /*
 150          * Number of times a flag fetch was requested.
 151          */
 152         SSIF_STAT_flag_fetches,
 153
 154         /*
 155          * Number of times the hardware didn't follow the state machine.
 156          */
 157         SSIF_STAT_hosed,
 158
 159         /*
 160          * Number of received events.
 161          */
 162         SSIF_STAT_events,
 163
 164         /* Number of asyncronous messages received. */
 165         SSIF_STAT_incoming_messages,
 166
 167         /* Number of watchdog pretimeouts. */
 168         SSIF_STAT_watchdog_pretimeouts,
 169
 170         /* Number of alers received. */
 171         SSIF_STAT_alerts,
 172
 173         /* Always add statistics before this value, it must be last. */
 174         SSIF_NUM_STATS
 175 };
 176
 177 struct ssif_addr_info {
 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         struct device *dev;
 185         struct i2c_client *client;
 186
 187         struct mutex clients_mutex;
 188         struct list_head clients;
 189
 190         struct list_head link;
 191 };
 192
 193 struct ssif_info;
 194
 195 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
 196                              unsigned char *data, unsigned int len);
 197
 198 struct ssif_info {
 199         struct ipmi_smi     *intf;
 200         spinlock_t          lock;
 201         struct ipmi_smi_msg *waiting_msg;
 202         struct ipmi_smi_msg *curr_msg;
 203         enum ssif_intf_state ssif_state;
 204         unsigned long       ssif_debug;
 205
 206         struct ipmi_smi_handlers handlers;
 207
 208         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
 209         union ipmi_smi_info_union addr_info;
 210
 211         /*
 212          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 213          * is set to hold the flags until we are done handling everything
 214          * from the flags.
 215          */
 216 #define RECEIVE_MSG_AVAIL       0x01
 217 #define EVENT_MSG_BUFFER_FULL   0x02
 218 #define WDT_PRE_TIMEOUT_INT     0x08
 219         unsigned char       msg_flags;
 220
 221         u8                  global_enables;
 222         bool                has_event_buffer;
 223         bool                supports_alert;
 224
 225         /*
 226          * Used to tell what we should do with alerts.  If we are
 227          * waiting on a response, read the data immediately.
 228          */
 229         bool                got_alert;
 230         bool                waiting_alert;
 231
 232         /*
 233          * If set to true, this will request events the next time the
 234          * state machine is idle.
 235          */
 236         bool                req_events;
 237
 238         /*
 239          * If set to true, this will request flags the next time the
 240          * state machine is idle.
 241          */
 242         bool                req_flags;
 243
 244         /*
 245          * Used to perform timer operations when run-to-completion
 246          * mode is on.  This is a countdown timer.
 247          */
 248         int                 rtc_us_timer;
 249
 250         /* Used for sending/receiving data.  +1 for the length. */
 251         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
 252         unsigned int  data_len;
 253
 254         /* Temp receive buffer, gets copied into data. */
 255         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
 256
 257         struct i2c_client *client;
 258         ssif_i2c_done done_handler;
 259
 260         /* Thread interface handling */
 261         struct task_struct *thread;
 262         struct completion wake_thread;
 263         bool stopping;
 264         int i2c_read_write;
 265         int i2c_command;
 266         unsigned char *i2c_data;
 267         unsigned int i2c_size;
 268
 269         struct timer_list retry_timer;
 270         int retries_left;
 271
 272         long watch_timeout;             /* Timeout for flags check, 0 if off. */
 273         struct timer_list watch_timer;  /* Flag fetch timer. */
 274
 275         /* Info from SSIF cmd */
 276         unsigned char max_xmit_msg_size;
 277         unsigned char max_recv_msg_size;
 278         bool cmd8_works; /* See test_multipart_messages() for details. */
 279         unsigned int  multi_support;
 280         int           supports_pec;
 281
 282 #define SSIF_NO_MULTI           0
 283 #define SSIF_MULTI_2_PART       1
 284 #define SSIF_MULTI_n_PART       2
 285         unsigned char *multi_data;
 286         unsigned int  multi_len;
 287         unsigned int  multi_pos;
 288
 289         atomic_t stats[SSIF_NUM_STATS];
 290 };
 291
 292 #define ssif_inc_stat(ssif, stat) \
 293         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
 294 #define ssif_get_stat(ssif, stat) \
 295         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
 296
 297 static bool initialized;
 298 static bool platform_registered;
 299
 300 static void return_hosed_msg(struct ssif_info *ssif_info,
 301                              struct ipmi_smi_msg *msg);
 302 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
 303 static int start_send(struct ssif_info *ssif_info,
 304                       unsigned char   *data,
 305                       unsigned int    len);
 306
 307 static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
 308                                           unsigned long *flags)
 309         __acquires(&ssif_info->lock)
 310 {
 311         spin_lock_irqsave(&ssif_info->lock, *flags);
 312         return flags;
 313 }
 314
 315 static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
 316                                   unsigned long *flags)
 317         __releases(&ssif_info->lock)
 318 {
 319         spin_unlock_irqrestore(&ssif_info->lock, *flags);
 320 }
 321
 322 static void deliver_recv_msg(struct ssif_info *ssif_info,
 323                              struct ipmi_smi_msg *msg)
 324 {
 325         if (msg->rsp_size < 0) {
 326                 return_hosed_msg(ssif_info, msg);
 327                 dev_err(&ssif_info->client->dev,
 328                         "%s: Malformed message: rsp_size = %d\n",
 329                        __func__, msg->rsp_size);
 330         } else {
 331                 ipmi_smi_msg_received(ssif_info->intf, msg);
 332         }
 333 }
 334
 335 static void return_hosed_msg(struct ssif_info *ssif_info,
 336                              struct ipmi_smi_msg *msg)
 337 {
 338         ssif_inc_stat(ssif_info, hosed);
 339
 340         /* Make it a response */
 341         msg->rsp[0] = msg->data[0] | 4;
 342         msg->rsp[1] = msg->data[1];
 343         msg->rsp[2] = 0xFF; /* Unknown error. */
 344         msg->rsp_size = 3;
 345
 346         deliver_recv_msg(ssif_info, msg);
 347 }
 348
 349 /*
 350  * Must be called with the message lock held.  This will release the
 351  * message lock.  Note that the caller will check SSIF_IDLE and start a
 352  * new operation, so there is no need to check for new messages to
 353  * start in here.
 354  */
 355 static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
 356 {
 357         unsigned char msg[3];
 358
 359         ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
 360         ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
 361         ipmi_ssif_unlock_cond(ssif_info, flags);
 362
 363         /* Make sure the watchdog pre-timeout flag is not set at startup. */
 364         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 365         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
 366         msg[2] = WDT_PRE_TIMEOUT_INT;
 367
 368         if (start_send(ssif_info, msg, 3) != 0) {
 369                 /* Error, just go to normal state. */
 370                 ssif_info->ssif_state = SSIF_NORMAL;
 371         }
 372 }
 373
 374 static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 375 {
 376         unsigned char mb[2];
 377
 378         ssif_info->req_flags = false;
 379         ssif_info->ssif_state = SSIF_GETTING_FLAGS;
 380         ipmi_ssif_unlock_cond(ssif_info, flags);
 381
 382         mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
 383         mb[1] = IPMI_GET_MSG_FLAGS_CMD;
 384         if (start_send(ssif_info, mb, 2) != 0)
 385                 ssif_info->ssif_state = SSIF_NORMAL;
 386 }
 387
 388 static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
 389                              struct ipmi_smi_msg *msg)
 390 {
 391         if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
 392                 unsigned long oflags;
 393
 394                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 395                 ssif_info->curr_msg = NULL;
 396                 ssif_info->ssif_state = SSIF_NORMAL;
 397                 ipmi_ssif_unlock_cond(ssif_info, flags);
 398                 ipmi_free_smi_msg(msg);
 399         }
 400 }
 401
 402 static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 403 {
 404         struct ipmi_smi_msg *msg;
 405
 406         ssif_info->req_events = false;
 407
 408         msg = ipmi_alloc_smi_msg();
 409         if (!msg) {
 410                 ssif_info->ssif_state = SSIF_NORMAL;
 411                 ipmi_ssif_unlock_cond(ssif_info, flags);
 412                 return;
 413         }
 414
 415         ssif_info->curr_msg = msg;
 416         ssif_info->ssif_state = SSIF_GETTING_EVENTS;
 417         ipmi_ssif_unlock_cond(ssif_info, flags);
 418
 419         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 420         msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
 421         msg->data_size = 2;
 422
 423         check_start_send(ssif_info, flags, msg);
 424 }
 425
 426 static void start_recv_msg_fetch(struct ssif_info *ssif_info,
 427                                  unsigned long *flags)
 428 {
 429         struct ipmi_smi_msg *msg;
 430
 431         msg = ipmi_alloc_smi_msg();
 432         if (!msg) {
 433                 ssif_info->ssif_state = SSIF_NORMAL;
 434                 ipmi_ssif_unlock_cond(ssif_info, flags);
 435                 return;
 436         }
 437
 438         ssif_info->curr_msg = msg;
 439         ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
 440         ipmi_ssif_unlock_cond(ssif_info, flags);
 441
 442         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 443         msg->data[1] = IPMI_GET_MSG_CMD;
 444         msg->data_size = 2;
 445
 446         check_start_send(ssif_info, flags, msg);
 447 }
 448
 449 /*
 450  * Must be called with the message lock held.  This will release the
 451  * message lock.  Note that the caller will check SSIF_IDLE and start a
 452  * new operation, so there is no need to check for new messages to
 453  * start in here.
 454  */
 455 static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
 456 {
 457         if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
 458                 /* Watchdog pre-timeout */
 459                 ssif_inc_stat(ssif_info, watchdog_pretimeouts);
 460                 start_clear_flags(ssif_info, flags);
 461                 ipmi_smi_watchdog_pretimeout(ssif_info->intf);
 462         } else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
 463                 /* Messages available. */
 464                 start_recv_msg_fetch(ssif_info, flags);
 465         else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
 466                 /* Events available. */
 467                 start_event_fetch(ssif_info, flags);
 468         else {
 469                 ssif_info->ssif_state = SSIF_NORMAL;
 470                 ipmi_ssif_unlock_cond(ssif_info, flags);
 471         }
 472 }
 473
 474 static int ipmi_ssif_thread(void *data)
 475 {
 476         struct ssif_info *ssif_info = data;
 477
 478         while (!kthread_should_stop()) {
 479                 int result;
 480
 481                 /* Wait for something to do */
 482                 result = wait_for_completion_interruptible(
 483                                                 &ssif_info->wake_thread);
 484                 if (ssif_info->stopping)
 485                         break;
 486                 if (result == -ERESTARTSYS)
 487                         continue;
 488                 init_completion(&ssif_info->wake_thread);
 489
 490                 if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
 491                         result = i2c_smbus_write_block_data(
 492                                 ssif_info->client, ssif_info->i2c_command,
 493                                 ssif_info->i2c_data[0],
 494                                 ssif_info->i2c_data + 1);
 495                         ssif_info->done_handler(ssif_info, result, NULL, 0);
 496                 } else {
 497                         result = i2c_smbus_read_block_data(
 498                                 ssif_info->client, ssif_info->i2c_command,
 499                                 ssif_info->i2c_data);
 500                         if (result < 0)
 501                                 ssif_info->done_handler(ssif_info, result,
 502                                                         NULL, 0);
 503                         else
 504                                 ssif_info->done_handler(ssif_info, 0,
 505                                                         ssif_info->i2c_data,
 506                                                         result);
 507                 }
 508         }
 509
 510         return 0;
 511 }
 512
 513 static int ssif_i2c_send(struct ssif_info *ssif_info,
 514                         ssif_i2c_done handler,
 515                         int read_write, int command,
 516                         unsigned char *data, unsigned int size)
 517 {
 518         ssif_info->done_handler = handler;
 519
 520         ssif_info->i2c_read_write = read_write;
 521         ssif_info->i2c_command = command;
 522         ssif_info->i2c_data = data;
 523         ssif_info->i2c_size = size;
 524         complete(&ssif_info->wake_thread);
 525         return 0;
 526 }
 527
 528
 529 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 530                              unsigned char *data, unsigned int len);
 531
 532 static void start_get(struct ssif_info *ssif_info)
 533 {
 534         int rv;
 535
 536         ssif_info->rtc_us_timer = 0;
 537         ssif_info->multi_pos = 0;
 538
 539         rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 540                           SSIF_IPMI_RESPONSE,
 541                           ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 542         if (rv < 0) {
 543                 /* request failed, just return the error. */
 544                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 545                         dev_dbg(&ssif_info->client->dev,
 546                                 "Error from i2c_non_blocking_op(5)\n");
 547
 548                 msg_done_handler(ssif_info, -EIO, NULL, 0);
 549         }
 550 }
 551
 552 static void retry_timeout(struct timer_list *t)
 553 {
 554         struct ssif_info *ssif_info = from_timer(ssif_info, t, retry_timer);
 555         unsigned long oflags, *flags;
 556         bool waiting;
 557
 558         if (ssif_info->stopping)
 559                 return;
 560
 561         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 562         waiting = ssif_info->waiting_alert;
 563         ssif_info->waiting_alert = false;
 564         ipmi_ssif_unlock_cond(ssif_info, flags);
 565
 566         if (waiting)
 567                 start_get(ssif_info);
 568 }
 569
 570 static void watch_timeout(struct timer_list *t)
 571 {
 572         struct ssif_info *ssif_info = from_timer(ssif_info, t, watch_timer);
 573         unsigned long oflags, *flags;
 574
 575         if (ssif_info->stopping)
 576                 return;
 577
 578         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 579         if (ssif_info->watch_timeout) {
 580                 mod_timer(&ssif_info->watch_timer,
 581                           jiffies + ssif_info->watch_timeout);
 582                 if (SSIF_IDLE(ssif_info)) {
 583                         start_flag_fetch(ssif_info, flags); /* Releases lock */
 584                         return;
 585                 }
 586                 ssif_info->req_flags = true;
 587         }
 588         ipmi_ssif_unlock_cond(ssif_info, flags);
 589 }
 590
 591 static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
 592                        unsigned int data)
 593 {
 594         struct ssif_info *ssif_info = i2c_get_clientdata(client);
 595         unsigned long oflags, *flags;
 596         bool do_get = false;
 597
 598         if (type != I2C_PROTOCOL_SMBUS_ALERT)
 599                 return;
 600
 601         ssif_inc_stat(ssif_info, alerts);
 602
 603         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 604         if (ssif_info->waiting_alert) {
 605                 ssif_info->waiting_alert = false;
 606                 del_timer(&ssif_info->retry_timer);
 607                 do_get = true;
 608         } else if (ssif_info->curr_msg) {
 609                 ssif_info->got_alert = true;
 610         }
 611         ipmi_ssif_unlock_cond(ssif_info, flags);
 612         if (do_get)
 613                 start_get(ssif_info);
 614 }
 615
 616 static int start_resend(struct ssif_info *ssif_info);
 617
 618 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 619                              unsigned char *data, unsigned int len)
 620 {
 621         struct ipmi_smi_msg *msg;
 622         unsigned long oflags, *flags;
 623         int rv;
 624
 625         /*
 626          * We are single-threaded here, so no need for a lock until we
 627          * start messing with driver states or the queues.
 628          */
 629
 630         if (result < 0) {
 631                 ssif_info->retries_left--;
 632                 if (ssif_info->retries_left > 0) {
 633                         ssif_inc_stat(ssif_info, receive_retries);
 634
 635                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 636                         ssif_info->waiting_alert = true;
 637                         ssif_info->rtc_us_timer = SSIF_MSG_USEC;
 638                         if (!ssif_info->stopping)
 639                                 mod_timer(&ssif_info->retry_timer,
 640                                           jiffies + SSIF_MSG_JIFFIES);
 641                         ipmi_ssif_unlock_cond(ssif_info, flags);
 642                         return;
 643                 }
 644
 645                 ssif_inc_stat(ssif_info, receive_errors);
 646
 647                 if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 648                         dev_dbg(&ssif_info->client->dev,
 649                                 "%s: Error %d\n", __func__, result);
 650                 len = 0;
 651                 goto continue_op;
 652         }
 653
 654         if ((len > 1) && (ssif_info->multi_pos == 0)
 655                                 && (data[0] == 0x00) && (data[1] == 0x01)) {
 656                 /* Start of multi-part read.  Start the next transaction. */
 657                 int i;
 658
 659                 ssif_inc_stat(ssif_info, received_message_parts);
 660
 661                 /* Remove the multi-part read marker. */
 662                 len -= 2;
 663                 data += 2;
 664                 for (i = 0; i < len; i++)
 665                         ssif_info->data[i] = data[i];
 666                 ssif_info->multi_len = len;
 667                 ssif_info->multi_pos = 1;
 668
 669                 rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 670                                   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 671                                   ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 672                 if (rv < 0) {
 673                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 674                                 dev_dbg(&ssif_info->client->dev,
 675                                         "Error from i2c_non_blocking_op(1)\n");
 676
 677                         result = -EIO;
 678                 } else
 679                         return;
 680         } else if (ssif_info->multi_pos) {
 681                 /* Middle of multi-part read.  Start the next transaction. */
 682                 int i;
 683                 unsigned char blocknum;
 684
 685                 if (len == 0) {
 686                         result = -EIO;
 687                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 688                                 dev_dbg(&ssif_info->client->dev,
 689                                         "Middle message with no data\n");
 690
 691                         goto continue_op;
 692                 }
 693
 694                 blocknum = data[0];
 695                 len--;
 696                 data++;
 697
 698                 if (blocknum != 0xff && len != 31) {
 699                     /* All blocks but the last must have 31 data bytes. */
 700                         result = -EIO;
 701                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 702                                 dev_dbg(&ssif_info->client->dev,
 703                                         "Received middle message <31\n");
 704
 705                         goto continue_op;
 706                 }
 707
 708                 if (ssif_info->multi_len + len > IPMI_MAX_MSG_LENGTH) {
 709                         /* Received message too big, abort the operation. */
 710                         result = -E2BIG;
 711                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 712                                 dev_dbg(&ssif_info->client->dev,
 713                                         "Received message too big\n");
 714
 715                         goto continue_op;
 716                 }
 717
 718                 for (i = 0; i < len; i++)
 719                         ssif_info->data[i + ssif_info->multi_len] = data[i];
 720                 ssif_info->multi_len += len;
 721                 if (blocknum == 0xff) {
 722                         /* End of read */
 723                         len = ssif_info->multi_len;
 724                         data = ssif_info->data;
 725                 } else if (blocknum + 1 != ssif_info->multi_pos) {
 726                         /*
 727                          * Out of sequence block, just abort.  Block
 728                          * numbers start at zero for the second block,
 729                          * but multi_pos starts at one, so the +1.
 730                          */
 731                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 732                                 dev_dbg(&ssif_info->client->dev,
 733                                         "Received message out of sequence, expected %u, got %u\n",
 734                                         ssif_info->multi_pos - 1, blocknum);
 735                         result = -EIO;
 736                 } else {
 737                         ssif_inc_stat(ssif_info, received_message_parts);
 738
 739                         ssif_info->multi_pos++;
 740
 741                         rv = ssif_i2c_send(ssif_info, msg_done_handler,
 742                                            I2C_SMBUS_READ,
 743                                            SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 744                                            ssif_info->recv,
 745                                            I2C_SMBUS_BLOCK_DATA);
 746                         if (rv < 0) {
 747                                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 748                                         dev_dbg(&ssif_info->client->dev,
 749                                                 "Error from ssif_i2c_send\n");
 750
 751                                 result = -EIO;
 752                         } else
 753                                 return;
 754                 }
 755         }
 756
 757  continue_op:
 758         if (result < 0) {
 759                 ssif_inc_stat(ssif_info, receive_errors);
 760         } else {
 761                 ssif_inc_stat(ssif_info, received_messages);
 762                 ssif_inc_stat(ssif_info, received_message_parts);
 763         }
 764
 765         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 766                 dev_dbg(&ssif_info->client->dev,
 767                         "DONE 1: state = %d, result=%d\n",
 768                         ssif_info->ssif_state, result);
 769
 770         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 771         msg = ssif_info->curr_msg;
 772         if (msg) {
 773                 if (data) {
 774                         if (len > IPMI_MAX_MSG_LENGTH)
 775                                 len = IPMI_MAX_MSG_LENGTH;
 776                         memcpy(msg->rsp, data, len);
 777                 } else {
 778                         len = 0;
 779                 }
 780                 msg->rsp_size = len;
 781                 ssif_info->curr_msg = NULL;
 782         }
 783
 784         switch (ssif_info->ssif_state) {
 785         case SSIF_NORMAL:
 786                 ipmi_ssif_unlock_cond(ssif_info, flags);
 787                 if (!msg)
 788                         break;
 789
 790                 if (result < 0)
 791                         return_hosed_msg(ssif_info, msg);
 792                 else
 793                         deliver_recv_msg(ssif_info, msg);
 794                 break;
 795
 796         case SSIF_GETTING_FLAGS:
 797                 /* We got the flags from the SSIF, now handle them. */
 798                 if ((result < 0) || (len < 4) || (data[2] != 0)) {
 799                         /*
 800                          * Error fetching flags, or invalid length,
 801                          * just give up for now.
 802                          */
 803                         ssif_info->ssif_state = SSIF_NORMAL;
 804                         ipmi_ssif_unlock_cond(ssif_info, flags);
 805                         dev_warn(&ssif_info->client->dev,
 806                                  "Error getting flags: %d %d, %x\n",
 807                                  result, len, (len >= 3) ? data[2] : 0);
 808                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 809                            || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
 810                         /*
 811                          * Don't abort here, maybe it was a queued
 812                          * response to a previous command.
 813                          */
 814                         ipmi_ssif_unlock_cond(ssif_info, flags);
 815                         dev_warn(&ssif_info->client->dev,
 816                                  "Invalid response getting flags: %x %x\n",
 817                                  data[0], data[1]);
 818                 } else {
 819                         ssif_inc_stat(ssif_info, flag_fetches);
 820                         ssif_info->msg_flags = data[3];
 821                         handle_flags(ssif_info, flags);
 822                 }
 823                 break;
 824
 825         case SSIF_CLEARING_FLAGS:
 826                 /* We cleared the flags. */
 827                 if ((result < 0) || (len < 3) || (data[2] != 0)) {
 828                         /* Error clearing flags */
 829                         dev_warn(&ssif_info->client->dev,
 830                                  "Error clearing flags: %d %d, %x\n",
 831                                  result, len, (len >= 3) ? data[2] : 0);
 832                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 833                            || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
 834                         dev_warn(&ssif_info->client->dev,
 835                                  "Invalid response clearing flags: %x %x\n",
 836                                  data[0], data[1]);
 837                 }
 838                 ssif_info->ssif_state = SSIF_NORMAL;
 839                 ipmi_ssif_unlock_cond(ssif_info, flags);
 840                 break;
 841
 842         case SSIF_GETTING_EVENTS:
 843                 if (!msg) {
 844                         /* Should never happen, but just in case. */
 845                         dev_warn(&ssif_info->client->dev,
 846                                  "No message set while getting events\n");
 847                         ipmi_ssif_unlock_cond(ssif_info, flags);
 848                         break;
 849                 }
 850
 851                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 852                         /* Error getting event, probably done. */
 853                         msg->done(msg);
 854
 855                         /* Take off the event flag. */
 856                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 857                         handle_flags(ssif_info, flags);
 858                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 859                            || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
 860                         dev_warn(&ssif_info->client->dev,
 861                                  "Invalid response getting events: %x %x\n",
 862                                  msg->rsp[0], msg->rsp[1]);
 863                         msg->done(msg);
 864                         /* Take off the event flag. */
 865                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 866                         handle_flags(ssif_info, flags);
 867                 } else {
 868                         handle_flags(ssif_info, flags);
 869                         ssif_inc_stat(ssif_info, events);
 870                         deliver_recv_msg(ssif_info, msg);
 871                 }
 872                 break;
 873
 874         case SSIF_GETTING_MESSAGES:
 875                 if (!msg) {
 876                         /* Should never happen, but just in case. */
 877                         dev_warn(&ssif_info->client->dev,
 878                                  "No message set while getting messages\n");
 879                         ipmi_ssif_unlock_cond(ssif_info, flags);
 880                         break;
 881                 }
 882
 883                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 884                         /* Error getting event, probably done. */
 885                         msg->done(msg);
 886
 887                         /* Take off the msg flag. */
 888                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 889                         handle_flags(ssif_info, flags);
 890                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 891                            || msg->rsp[1] != IPMI_GET_MSG_CMD) {
 892                         dev_warn(&ssif_info->client->dev,
 893                                  "Invalid response clearing flags: %x %x\n",
 894                                  msg->rsp[0], msg->rsp[1]);
 895                         msg->done(msg);
 896
 897                         /* Take off the msg flag. */
 898                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 899                         handle_flags(ssif_info, flags);
 900                 } else {
 901                         ssif_inc_stat(ssif_info, incoming_messages);
 902                         handle_flags(ssif_info, flags);
 903                         deliver_recv_msg(ssif_info, msg);
 904                 }
 905                 break;
 906
 907         default:
 908                 /* Should never happen, but just in case. */
 909                 dev_warn(&ssif_info->client->dev,
 910                          "Invalid state in message done handling: %d\n",
 911                          ssif_info->ssif_state);
 912                 ipmi_ssif_unlock_cond(ssif_info, flags);
 913         }
 914
 915         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 916         if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
 917                 if (ssif_info->req_events)
 918                         start_event_fetch(ssif_info, flags);
 919                 else if (ssif_info->req_flags)
 920                         start_flag_fetch(ssif_info, flags);
 921                 else
 922                         start_next_msg(ssif_info, flags);
 923         } else
 924                 ipmi_ssif_unlock_cond(ssif_info, flags);
 925
 926         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 927                 dev_dbg(&ssif_info->client->dev,
 928                         "DONE 2: state = %d.\n", ssif_info->ssif_state);
 929 }
 930
 931 static void msg_written_handler(struct ssif_info *ssif_info, int result,
 932                                 unsigned char *data, unsigned int len)
 933 {
 934         int rv;
 935
 936         /* We are single-threaded here, so no need for a lock. */
 937         if (result < 0) {
 938                 ssif_info->retries_left--;
 939                 if (ssif_info->retries_left > 0) {
 940                         if (!start_resend(ssif_info)) {
 941                                 ssif_inc_stat(ssif_info, send_retries);
 942                                 return;
 943                         }
 944                         /* request failed, just return the error. */
 945                         ssif_inc_stat(ssif_info, send_errors);
 946
 947                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 948                                 dev_dbg(&ssif_info->client->dev,
 949                                         "%s: Out of retries\n", __func__);
 950                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 951                         return;
 952                 }
 953
 954                 ssif_inc_stat(ssif_info, send_errors);
 955
 956                 /*
 957                  * Got an error on transmit, let the done routine
 958                  * handle it.
 959                  */
 960                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 961                         dev_dbg(&ssif_info->client->dev,
 962                                 "%s: Error  %d\n", __func__, result);
 963
 964                 msg_done_handler(ssif_info, result, NULL, 0);
 965                 return;
 966         }
 967
 968         if (ssif_info->multi_data) {
 969                 /*
 970                  * In the middle of a multi-data write.  See the comment
 971                  * in the SSIF_MULTI_n_PART case in the probe function
 972                  * for details on the intricacies of this.
 973                  */
 974                 int left, to_write;
 975                 unsigned char *data_to_send;
 976                 unsigned char cmd;
 977
 978                 ssif_inc_stat(ssif_info, sent_messages_parts);
 979
 980                 left = ssif_info->multi_len - ssif_info->multi_pos;
 981                 to_write = left;
 982                 if (to_write > 32)
 983                         to_write = 32;
 984                 /* Length byte. */
 985                 ssif_info->multi_data[ssif_info->multi_pos] = to_write;
 986                 data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
 987                 ssif_info->multi_pos += to_write;
 988                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE;
 989                 if (ssif_info->cmd8_works) {
 990                         if (left == to_write) {
 991                                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_END;
 992                                 ssif_info->multi_data = NULL;
 993                         }
 994                 } else if (to_write < 32) {
 995                         ssif_info->multi_data = NULL;
 996                 }
 997
 998                 rv = ssif_i2c_send(ssif_info, msg_written_handler,
 999                                    I2C_SMBUS_WRITE, cmd,
1000                                    data_to_send, I2C_SMBUS_BLOCK_DATA);
1001                 if (rv < 0) {
1002                         /* request failed, just return the error. */
1003                         ssif_inc_stat(ssif_info, send_errors);
1004
1005                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
1006                                 dev_dbg(&ssif_info->client->dev,
1007                                         "Error from i2c_non_blocking_op(3)\n");
1008                         msg_done_handler(ssif_info, -EIO, NULL, 0);
1009                 }
1010         } else {
1011                 /* Ready to request the result. */
1012                 unsigned long oflags, *flags;
1013
1014                 ssif_inc_stat(ssif_info, sent_messages);
1015                 ssif_inc_stat(ssif_info, sent_messages_parts);
1016
1017                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1018                 if (ssif_info->got_alert) {
1019                         /* The result is already ready, just start it. */
1020                         ssif_info->got_alert = false;
1021                         ipmi_ssif_unlock_cond(ssif_info, flags);
1022                         start_get(ssif_info);
1023                 } else {
1024                         /* Wait a jiffie then request the next message */
1025                         ssif_info->waiting_alert = true;
1026                         ssif_info->retries_left = SSIF_RECV_RETRIES;
1027                         ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
1028                         if (!ssif_info->stopping)
1029                                 mod_timer(&ssif_info->retry_timer,
1030                                           jiffies + SSIF_MSG_PART_JIFFIES);
1031                         ipmi_ssif_unlock_cond(ssif_info, flags);
1032                 }
1033         }
1034 }
1035
1036 static int start_resend(struct ssif_info *ssif_info)
1037 {
1038         int rv;
1039         int command;
1040
1041         ssif_info->got_alert = false;
1042
1043         if (ssif_info->data_len > 32) {
1044                 command = SSIF_IPMI_MULTI_PART_REQUEST_START;
1045                 ssif_info->multi_data = ssif_info->data;
1046                 ssif_info->multi_len = ssif_info->data_len;
1047                 /*
1048                  * Subtle thing, this is 32, not 33, because we will
1049                  * overwrite the thing at position 32 (which was just
1050                  * transmitted) with the new length.
1051                  */
1052                 ssif_info->multi_pos = 32;
1053                 ssif_info->data[0] = 32;
1054         } else {
1055                 ssif_info->multi_data = NULL;
1056                 command = SSIF_IPMI_REQUEST;
1057                 ssif_info->data[0] = ssif_info->data_len;
1058         }
1059
1060         rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
1061                           command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
1062         if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
1063                 dev_dbg(&ssif_info->client->dev,
1064                         "Error from i2c_non_blocking_op(4)\n");
1065         return rv;
1066 }
1067
1068 static int start_send(struct ssif_info *ssif_info,
1069                       unsigned char   *data,
1070                       unsigned int    len)
1071 {
1072         if (len > IPMI_MAX_MSG_LENGTH)
1073                 return -E2BIG;
1074         if (len > ssif_info->max_xmit_msg_size)
1075                 return -E2BIG;
1076
1077         ssif_info->retries_left = SSIF_SEND_RETRIES;
1078         memcpy(ssif_info->data + 1, data, len);
1079         ssif_info->data_len = len;
1080         return start_resend(ssif_info);
1081 }
1082
1083 /* Must be called with the message lock held. */
1084 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
1085 {
1086         struct ipmi_smi_msg *msg;
1087         unsigned long oflags;
1088
1089  restart:
1090         if (!SSIF_IDLE(ssif_info)) {
1091                 ipmi_ssif_unlock_cond(ssif_info, flags);
1092                 return;
1093         }
1094
1095         if (!ssif_info->waiting_msg) {
1096                 ssif_info->curr_msg = NULL;
1097                 ipmi_ssif_unlock_cond(ssif_info, flags);
1098         } else {
1099                 int rv;
1100
1101                 ssif_info->curr_msg = ssif_info->waiting_msg;
1102                 ssif_info->waiting_msg = NULL;
1103                 ipmi_ssif_unlock_cond(ssif_info, flags);
1104                 rv = start_send(ssif_info,
1105                                 ssif_info->curr_msg->data,
1106                                 ssif_info->curr_msg->data_size);
1107                 if (rv) {
1108                         msg = ssif_info->curr_msg;
1109                         ssif_info->curr_msg = NULL;
1110                         return_hosed_msg(ssif_info, msg);
1111                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1112                         goto restart;
1113                 }
1114         }
1115 }
1116
1117 static void sender(void                *send_info,
1118                    struct ipmi_smi_msg *msg)
1119 {
1120         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1121         unsigned long oflags, *flags;
1122
1123         BUG_ON(ssif_info->waiting_msg);
1124         ssif_info->waiting_msg = msg;
1125
1126         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1127         start_next_msg(ssif_info, flags);
1128
1129         if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1130                 struct timespec64 t;
1131
1132                 ktime_get_real_ts64(&t);
1133                 dev_dbg(&ssif_info->client->dev,
1134                         "**Enqueue %02x %02x: %lld.%6.6ld\n",
1135                         msg->data[0], msg->data[1],
1136                         (long long)t.tv_sec, (long)t.tv_nsec / NSEC_PER_USEC);
1137         }
1138 }
1139
1140 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1141 {
1142         struct ssif_info *ssif_info = send_info;
1143
1144         data->addr_src = ssif_info->addr_source;
1145         data->dev = &ssif_info->client->dev;
1146         data->addr_info = ssif_info->addr_info;
1147         get_device(data->dev);
1148
1149         return 0;
1150 }
1151
1152 /*
1153  * Upper layer wants us to request events.
1154  */
1155 static void request_events(void *send_info)
1156 {
1157         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1158         unsigned long oflags, *flags;
1159
1160         if (!ssif_info->has_event_buffer)
1161                 return;
1162
1163         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1164         ssif_info->req_events = true;
1165         ipmi_ssif_unlock_cond(ssif_info, flags);
1166 }
1167
1168 /*
1169  * Upper layer is changing the flag saying whether we need to request
1170  * flags periodically or not.
1171  */
1172 static void ssif_set_need_watch(void *send_info, unsigned int watch_mask)
1173 {
1174         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1175         unsigned long oflags, *flags;
1176         long timeout = 0;
1177
1178         if (watch_mask & IPMI_WATCH_MASK_CHECK_MESSAGES)
1179                 timeout = SSIF_WATCH_MSG_TIMEOUT;
1180         else if (watch_mask)
1181                 timeout = SSIF_WATCH_WATCHDOG_TIMEOUT;
1182
1183         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1184         if (timeout != ssif_info->watch_timeout) {
1185                 ssif_info->watch_timeout = timeout;
1186                 if (ssif_info->watch_timeout)
1187                         mod_timer(&ssif_info->watch_timer,
1188                                   jiffies + ssif_info->watch_timeout);
1189         }
1190         ipmi_ssif_unlock_cond(ssif_info, flags);
1191 }
1192
1193 static int ssif_start_processing(void            *send_info,
1194                                  struct ipmi_smi *intf)
1195 {
1196         struct ssif_info *ssif_info = send_info;
1197
1198         ssif_info->intf = intf;
1199
1200         return 0;
1201 }
1202
1203 #define MAX_SSIF_BMCS 4
1204
1205 static unsigned short addr[MAX_SSIF_BMCS];
1206 static int num_addrs;
1207 module_param_array(addr, ushort, &num_addrs, 0);
1208 MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1209
1210 static char *adapter_name[MAX_SSIF_BMCS];
1211 static int num_adapter_names;
1212 module_param_array(adapter_name, charp, &num_adapter_names, 0);
1213 MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1214
1215 static int slave_addrs[MAX_SSIF_BMCS];
1216 static int num_slave_addrs;
1217 module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1218 MODULE_PARM_DESC(slave_addrs,
1219                  "The default IPMB slave address for the controller.");
1220
1221 static bool alerts_broken;
1222 module_param(alerts_broken, bool, 0);
1223 MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1224
1225 /*
1226  * Bit 0 enables message debugging, bit 1 enables state debugging, and
1227  * bit 2 enables timing debugging.  This is an array indexed by
1228  * interface number"
1229  */
1230 static int dbg[MAX_SSIF_BMCS];
1231 static int num_dbg;
1232 module_param_array(dbg, int, &num_dbg, 0);
1233 MODULE_PARM_DESC(dbg, "Turn on debugging.");
1234
1235 static bool ssif_dbg_probe;
1236 module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1237 MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1238
1239 static bool ssif_tryacpi = true;
1240 module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1241 MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1242
1243 static bool ssif_trydmi = true;
1244 module_param_named(trydmi, ssif_trydmi, bool, 0);
1245 MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1246
1247 static DEFINE_MUTEX(ssif_infos_mutex);
1248 static LIST_HEAD(ssif_infos);
1249
1250 #define IPMI_SSIF_ATTR(name) \
1251 static ssize_t ipmi_##name##_show(struct device *dev,                   \
1252                                   struct device_attribute *attr,        \
1253                                   char *buf)                            \
1254 {                                                                       \
1255         struct ssif_info *ssif_info = dev_get_drvdata(dev);             \
1256                                                                         \
1257         return snprintf(buf, 10, "%u\n", ssif_get_stat(ssif_info, name));\
1258 }                                                                       \
1259 static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL)
1260
1261 static ssize_t ipmi_type_show(struct device *dev,
1262                               struct device_attribute *attr,
1263                               char *buf)
1264 {
1265         return snprintf(buf, 10, "ssif\n");
1266 }
1267 static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL);
1268
1269 IPMI_SSIF_ATTR(sent_messages);
1270 IPMI_SSIF_ATTR(sent_messages_parts);
1271 IPMI_SSIF_ATTR(send_retries);
1272 IPMI_SSIF_ATTR(send_errors);
1273 IPMI_SSIF_ATTR(received_messages);
1274 IPMI_SSIF_ATTR(received_message_parts);
1275 IPMI_SSIF_ATTR(receive_retries);
1276 IPMI_SSIF_ATTR(receive_errors);
1277 IPMI_SSIF_ATTR(flag_fetches);
1278 IPMI_SSIF_ATTR(hosed);
1279 IPMI_SSIF_ATTR(events);
1280 IPMI_SSIF_ATTR(watchdog_pretimeouts);
1281 IPMI_SSIF_ATTR(alerts);
1282
1283 static struct attribute *ipmi_ssif_dev_attrs[] = {
1284         &dev_attr_type.attr,
1285         &dev_attr_sent_messages.attr,
1286         &dev_attr_sent_messages_parts.attr,
1287         &dev_attr_send_retries.attr,
1288         &dev_attr_send_errors.attr,
1289         &dev_attr_received_messages.attr,
1290         &dev_attr_received_message_parts.attr,
1291         &dev_attr_receive_retries.attr,
1292         &dev_attr_receive_errors.attr,
1293         &dev_attr_flag_fetches.attr,
1294         &dev_attr_hosed.attr,
1295         &dev_attr_events.attr,
1296         &dev_attr_watchdog_pretimeouts.attr,
1297         &dev_attr_alerts.attr,
1298         NULL
1299 };
1300
1301 static const struct attribute_group ipmi_ssif_dev_attr_group = {
1302         .attrs          = ipmi_ssif_dev_attrs,
1303 };
1304
1305 static void shutdown_ssif(void *send_info)
1306 {
1307         struct ssif_info *ssif_info = send_info;
1308
1309         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1310         dev_set_drvdata(&ssif_info->client->dev, NULL);
1311
1312         /* make sure the driver is not looking for flags any more. */
1313         while (ssif_info->ssif_state != SSIF_NORMAL)
1314                 schedule_timeout(1);
1315
1316         ssif_info->stopping = true;
1317         del_timer_sync(&ssif_info->watch_timer);
1318         del_timer_sync(&ssif_info->retry_timer);
1319         if (ssif_info->thread) {
1320                 complete(&ssif_info->wake_thread);
1321                 kthread_stop(ssif_info->thread);
1322         }
1323 }
1324
1325 static int ssif_remove(struct i2c_client *client)
1326 {
1327         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1328         struct ssif_addr_info *addr_info;
1329
1330         if (!ssif_info)
1331                 return 0;
1332
1333         /*
1334          * After this point, we won't deliver anything asychronously
1335          * to the message handler.  We can unregister ourself.
1336          */
1337         ipmi_unregister_smi(ssif_info->intf);
1338
1339         list_for_each_entry(addr_info, &ssif_infos, link) {
1340                 if (addr_info->client == client) {
1341                         addr_info->client = NULL;
1342                         break;
1343                 }
1344         }
1345
1346         kfree(ssif_info);
1347
1348         return 0;
1349 }
1350
1351 static int read_response(struct i2c_client *client, unsigned char *resp)
1352 {
1353         int ret = -ENODEV, retry_cnt = SSIF_RECV_RETRIES;
1354
1355         while (retry_cnt > 0) {
1356                 ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1357                                                 resp);
1358                 if (ret > 0)
1359                         break;
1360                 msleep(SSIF_MSG_MSEC);
1361                 retry_cnt--;
1362                 if (retry_cnt <= 0)
1363                         break;
1364         }
1365
1366         return ret;
1367 }
1368
1369 static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1370                   int *resp_len, unsigned char *resp)
1371 {
1372         int retry_cnt;
1373         int ret;
1374
1375         retry_cnt = SSIF_SEND_RETRIES;
1376  retry1:
1377         ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1378         if (ret) {
1379                 retry_cnt--;
1380                 if (retry_cnt > 0)
1381                         goto retry1;
1382                 return -ENODEV;
1383         }
1384
1385         ret = read_response(client, resp);
1386         if (ret > 0) {
1387                 /* Validate that the response is correct. */
1388                 if (ret < 3 ||
1389                     (resp[0] != (msg[0] | (1 << 2))) ||
1390                     (resp[1] != msg[1]))
1391                         ret = -EINVAL;
1392                 else if (ret > IPMI_MAX_MSG_LENGTH) {
1393                         ret = -E2BIG;
1394                 } else {
1395                         *resp_len = ret;
1396                         ret = 0;
1397                 }
1398         }
1399
1400         return ret;
1401 }
1402
1403 static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1404 {
1405         unsigned char *resp;
1406         unsigned char msg[3];
1407         int           rv;
1408         int           len;
1409
1410         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1411         if (!resp)
1412                 return -ENOMEM;
1413
1414         /* Do a Get Device ID command, since it is required. */
1415         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1416         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1417         rv = do_cmd(client, 2, msg, &len, resp);
1418         if (rv)
1419                 rv = -ENODEV;
1420         else
1421                 strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1422         kfree(resp);
1423         return rv;
1424 }
1425
1426 static int strcmp_nospace(char *s1, char *s2)
1427 {
1428         while (*s1 && *s2) {
1429                 while (isspace(*s1))
1430                         s1++;
1431                 while (isspace(*s2))
1432                         s2++;
1433                 if (*s1 > *s2)
1434                         return 1;
1435                 if (*s1 < *s2)
1436                         return -1;
1437                 s1++;
1438                 s2++;
1439         }
1440         return 0;
1441 }
1442
1443 static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1444                                              char *adapter_name,
1445                                              bool match_null_name)
1446 {
1447         struct ssif_addr_info *info, *found = NULL;
1448
1449 restart:
1450         list_for_each_entry(info, &ssif_infos, link) {
1451                 if (info->binfo.addr == addr) {
1452                         if (info->addr_src == SI_SMBIOS)
1453                                 info->adapter_name = kstrdup(adapter_name,
1454                                                              GFP_KERNEL);
1455
1456                         if (info->adapter_name || adapter_name) {
1457                                 if (!info->adapter_name != !adapter_name) {
1458                                         /* One is NULL and one is not */
1459                                         continue;
1460                                 }
1461                                 if (adapter_name &&
1462                                     strcmp_nospace(info->adapter_name,
1463                                                    adapter_name))
1464                                         /* Names do not match */
1465                                         continue;
1466                         }
1467                         found = info;
1468                         break;
1469                 }
1470         }
1471
1472         if (!found && match_null_name) {
1473                 /* Try to get an exact match first, then try with a NULL name */
1474                 adapter_name = NULL;
1475                 match_null_name = false;
1476                 goto restart;
1477         }
1478
1479         return found;
1480 }
1481
1482 static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1483 {
1484 #ifdef CONFIG_ACPI
1485         acpi_handle acpi_handle;
1486
1487         acpi_handle = ACPI_HANDLE(dev);
1488         if (acpi_handle) {
1489                 ssif_info->addr_source = SI_ACPI;
1490                 ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1491                 request_module("acpi_ipmi");
1492                 return true;
1493         }
1494 #endif
1495         return false;
1496 }
1497
1498 static int find_slave_address(struct i2c_client *client, int slave_addr)
1499 {
1500 #ifdef CONFIG_IPMI_DMI_DECODE
1501         if (!slave_addr)
1502                 slave_addr = ipmi_dmi_get_slave_addr(
1503                         SI_TYPE_INVALID,
1504                         i2c_adapter_id(client->adapter),
1505                         client->addr);
1506 #endif
1507
1508         return slave_addr;
1509 }
1510
1511 static int start_multipart_test(struct i2c_client *client,
1512                                 unsigned char *msg, bool do_middle)
1513 {
1514         int retry_cnt = SSIF_SEND_RETRIES, ret;
1515
1516 retry_write:
1517         ret = i2c_smbus_write_block_data(client,
1518                                          SSIF_IPMI_MULTI_PART_REQUEST_START,
1519                                          32, msg);
1520         if (ret) {
1521                 retry_cnt--;
1522                 if (retry_cnt > 0)
1523                         goto retry_write;
1524                 dev_err(&client->dev, "Could not write multi-part start, though the BMC said it could handle it.  Just limit sends to one part.\n");
1525                 return ret;
1526         }
1527
1528         if (!do_middle)
1529                 return 0;
1530
1531         ret = i2c_smbus_write_block_data(client,
1532                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1533                                          32, msg + 32);
1534         if (ret) {
1535                 dev_err(&client->dev, "Could not write multi-part middle, though the BMC said it could handle it.  Just limit sends to one part.\n");
1536                 return ret;
1537         }
1538
1539         return 0;
1540 }
1541
1542 static void test_multipart_messages(struct i2c_client *client,
1543                                     struct ssif_info *ssif_info,
1544                                     unsigned char *resp)
1545 {
1546         unsigned char msg[65];
1547         int ret;
1548         bool do_middle;
1549
1550         if (ssif_info->max_xmit_msg_size <= 32)
1551                 return;
1552
1553         do_middle = ssif_info->max_xmit_msg_size > 63;
1554
1555         memset(msg, 0, sizeof(msg));
1556         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1557         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1558
1559         /*
1560          * The specification is all messed up dealing with sending
1561          * multi-part messages.  Per what the specification says, it
1562          * is impossible to send a message that is a multiple of 32
1563          * bytes, except for 32 itself.  It talks about a "start"
1564          * transaction (cmd=6) that must be 32 bytes, "middle"
1565          * transaction (cmd=7) that must be 32 bytes, and an "end"
1566          * transaction.  The "end" transaction is shown as cmd=7 in
1567          * the text, but if that's the case there is no way to
1568          * differentiate between a middle and end part except the
1569          * length being less than 32.  But there is a table at the far
1570          * end of the section (that I had never noticed until someone
1571          * pointed it out to me) that mentions it as cmd=8.
1572          *
1573          * After some thought, I think the example is wrong and the
1574          * end transaction should be cmd=8.  But some systems don't
1575          * implement cmd=8, they use a zero-length end transaction,
1576          * even though that violates the SMBus specification.
1577          *
1578          * So, to work around this, this code tests if cmd=8 works.
1579          * If it does, then we use that.  If not, it tests zero-
1580          * byte end transactions.  If that works, good.  If not,
1581          * we only allow 63-byte transactions max.
1582          */
1583
1584         ret = start_multipart_test(client, msg, do_middle);
1585         if (ret)
1586                 goto out_no_multi_part;
1587
1588         ret = i2c_smbus_write_block_data(client,
1589                                          SSIF_IPMI_MULTI_PART_REQUEST_END,
1590                                          1, msg + 64);
1591
1592         if (!ret)
1593                 ret = read_response(client, resp);
1594
1595         if (ret > 0) {
1596                 /* End transactions work, we are good. */
1597                 ssif_info->cmd8_works = true;
1598                 return;
1599         }
1600
1601         ret = start_multipart_test(client, msg, do_middle);
1602         if (ret) {
1603                 dev_err(&client->dev, "Second multipart test failed.\n");
1604                 goto out_no_multi_part;
1605         }
1606
1607         ret = i2c_smbus_write_block_data(client,
1608                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1609                                          0, msg + 64);
1610         if (!ret)
1611                 ret = read_response(client, resp);
1612         if (ret > 0)
1613                 /* Zero-size end parts work, use those. */
1614                 return;
1615
1616         /* Limit to 63 bytes and use a short middle command to mark the end. */
1617         if (ssif_info->max_xmit_msg_size > 63)
1618                 ssif_info->max_xmit_msg_size = 63;
1619         return;
1620
1621 out_no_multi_part:
1622         ssif_info->max_xmit_msg_size = 32;
1623         return;
1624 }
1625
1626 /*
1627  * Global enables we care about.
1628  */
1629 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1630                              IPMI_BMC_EVT_MSG_INTR)
1631
1632 static void ssif_remove_dup(struct i2c_client *client)
1633 {
1634         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1635
1636         ipmi_unregister_smi(ssif_info->intf);
1637         kfree(ssif_info);
1638 }
1639
1640 static int ssif_add_infos(struct i2c_client *client)
1641 {
1642         struct ssif_addr_info *info;
1643
1644         info = kzalloc(sizeof(*info), GFP_KERNEL);
1645         if (!info)
1646                 return -ENOMEM;
1647         info->addr_src = SI_ACPI;
1648         info->client = client;
1649         info->adapter_name = kstrdup(client->adapter->name, GFP_KERNEL);
1650         info->binfo.addr = client->addr;
1651         list_add_tail(&info->link, &ssif_infos);
1652         return 0;
1653 }
1654
1655 /*
1656  * Prefer ACPI over SMBIOS, if both are available.
1657  * So if we get an ACPI interface and have already registered a SMBIOS
1658  * interface at the same address, remove the SMBIOS and add the ACPI one.
1659  */
1660 static int ssif_check_and_remove(struct i2c_client *client,
1661                               struct ssif_info *ssif_info)
1662 {
1663         struct ssif_addr_info *info;
1664
1665         list_for_each_entry(info, &ssif_infos, link) {
1666                 if (!info->client)
1667                         return 0;
1668                 if (!strcmp(info->adapter_name, client->adapter->name) &&
1669                     info->binfo.addr == client->addr) {
1670                         if (info->addr_src == SI_ACPI)
1671                                 return -EEXIST;
1672
1673                         if (ssif_info->addr_source == SI_ACPI &&
1674                             info->addr_src == SI_SMBIOS) {
1675                                 dev_info(&client->dev,
1676                                          "Removing %s-specified SSIF interface in favor of ACPI\n",
1677                                          ipmi_addr_src_to_str(info->addr_src));
1678                                 ssif_remove_dup(info->client);
1679                                 return 0;
1680                         }
1681                 }
1682         }
1683         return 0;
1684 }
1685
1686 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1687 {
1688         unsigned char     msg[3];
1689         unsigned char     *resp;
1690         struct ssif_info   *ssif_info;
1691         int               rv = 0;
1692         int               len;
1693         int               i;
1694         u8                slave_addr = 0;
1695         struct ssif_addr_info *addr_info = NULL;
1696
1697         mutex_lock(&ssif_infos_mutex);
1698         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1699         if (!resp) {
1700                 mutex_unlock(&ssif_infos_mutex);
1701                 return -ENOMEM;
1702         }
1703
1704         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1705         if (!ssif_info) {
1706                 kfree(resp);
1707                 mutex_unlock(&ssif_infos_mutex);
1708                 return -ENOMEM;
1709         }
1710
1711         if (!check_acpi(ssif_info, &client->dev)) {
1712                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1713                                            true);
1714                 if (!addr_info) {
1715                         /* Must have come in through sysfs. */
1716                         ssif_info->addr_source = SI_HOTMOD;
1717                 } else {
1718                         ssif_info->addr_source = addr_info->addr_src;
1719                         ssif_info->ssif_debug = addr_info->debug;
1720                         ssif_info->addr_info = addr_info->addr_info;
1721                         addr_info->client = client;
1722                         slave_addr = addr_info->slave_addr;
1723                 }
1724         }
1725
1726         ssif_info->client = client;
1727         i2c_set_clientdata(client, ssif_info);
1728
1729         rv = ssif_check_and_remove(client, ssif_info);
1730         /* If rv is 0 and addr source is not SI_ACPI, continue probing */
1731         if (!rv && ssif_info->addr_source == SI_ACPI) {
1732                 rv = ssif_add_infos(client);
1733                 if (rv) {
1734                         dev_err(&client->dev, "Out of memory!, exiting ..\n");
1735                         goto out;
1736                 }
1737         } else if (rv) {
1738                 dev_err(&client->dev, "Not probing, Interface already present\n");
1739                 goto out;
1740         }
1741
1742         slave_addr = find_slave_address(client, slave_addr);
1743
1744         dev_info(&client->dev,
1745                  "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1746                 ipmi_addr_src_to_str(ssif_info->addr_source),
1747                 client->addr, client->adapter->name, slave_addr);
1748
1749         /* Now check for system interface capabilities */
1750         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1751         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1752         msg[2] = 0; /* SSIF */
1753         rv = do_cmd(client, 3, msg, &len, resp);
1754         if (!rv && (len >= 3) && (resp[2] == 0)) {
1755                 if (len < 7) {
1756                         if (ssif_dbg_probe)
1757                                 dev_dbg(&ssif_info->client->dev,
1758                                         "SSIF info too short: %d\n", len);
1759                         goto no_support;
1760                 }
1761
1762                 /* Got a good SSIF response, handle it. */
1763                 ssif_info->max_xmit_msg_size = resp[5];
1764                 ssif_info->max_recv_msg_size = resp[6];
1765                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1766                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1767
1768                 /* Sanitize the data */
1769                 switch (ssif_info->multi_support) {
1770                 case SSIF_NO_MULTI:
1771                         if (ssif_info->max_xmit_msg_size > 32)
1772                                 ssif_info->max_xmit_msg_size = 32;
1773                         if (ssif_info->max_recv_msg_size > 32)
1774                                 ssif_info->max_recv_msg_size = 32;
1775                         break;
1776
1777                 case SSIF_MULTI_2_PART:
1778                         if (ssif_info->max_xmit_msg_size > 63)
1779                                 ssif_info->max_xmit_msg_size = 63;
1780                         if (ssif_info->max_recv_msg_size > 62)
1781                                 ssif_info->max_recv_msg_size = 62;
1782                         break;
1783
1784                 case SSIF_MULTI_n_PART:
1785                         /* We take whatever size given, but do some testing. */
1786                         break;
1787
1788                 default:
1789                         /* Data is not sane, just give up. */
1790                         goto no_support;
1791                 }
1792         } else {
1793  no_support:
1794                 /* Assume no multi-part or PEC support */
1795                 dev_info(&ssif_info->client->dev,
1796                          "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1797                         rv, len, resp[2]);
1798
1799                 ssif_info->max_xmit_msg_size = 32;
1800                 ssif_info->max_recv_msg_size = 32;
1801                 ssif_info->multi_support = SSIF_NO_MULTI;
1802                 ssif_info->supports_pec = 0;
1803         }
1804
1805         test_multipart_messages(client, ssif_info, resp);
1806
1807         /* Make sure the NMI timeout is cleared. */
1808         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1809         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1810         msg[2] = WDT_PRE_TIMEOUT_INT;
1811         rv = do_cmd(client, 3, msg, &len, resp);
1812         if (rv || (len < 3) || (resp[2] != 0))
1813                 dev_warn(&ssif_info->client->dev,
1814                          "Unable to clear message flags: %d %d %2.2x\n",
1815                          rv, len, resp[2]);
1816
1817         /* Attempt to enable the event buffer. */
1818         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1819         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1820         rv = do_cmd(client, 2, msg, &len, resp);
1821         if (rv || (len < 4) || (resp[2] != 0)) {
1822                 dev_warn(&ssif_info->client->dev,
1823                          "Error getting global enables: %d %d %2.2x\n",
1824                          rv, len, resp[2]);
1825                 rv = 0; /* Not fatal */
1826                 goto found;
1827         }
1828
1829         ssif_info->global_enables = resp[3];
1830
1831         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1832                 ssif_info->has_event_buffer = true;
1833                 /* buffer is already enabled, nothing to do. */
1834                 goto found;
1835         }
1836
1837         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1838         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1839         msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1840         rv = do_cmd(client, 3, msg, &len, resp);
1841         if (rv || (len < 2)) {
1842                 dev_warn(&ssif_info->client->dev,
1843                          "Error setting global enables: %d %d %2.2x\n",
1844                          rv, len, resp[2]);
1845                 rv = 0; /* Not fatal */
1846                 goto found;
1847         }
1848
1849         if (resp[2] == 0) {
1850                 /* A successful return means the event buffer is supported. */
1851                 ssif_info->has_event_buffer = true;
1852                 ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1853         }
1854
1855         /* Some systems don't behave well if you enable alerts. */
1856         if (alerts_broken)
1857                 goto found;
1858
1859         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1860         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1861         msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1862         rv = do_cmd(client, 3, msg, &len, resp);
1863         if (rv || (len < 2)) {
1864                 dev_warn(&ssif_info->client->dev,
1865                          "Error setting global enables: %d %d %2.2x\n",
1866                          rv, len, resp[2]);
1867                 rv = 0; /* Not fatal */
1868                 goto found;
1869         }
1870
1871         if (resp[2] == 0) {
1872                 /* A successful return means the alert is supported. */
1873                 ssif_info->supports_alert = true;
1874                 ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1875         }
1876
1877  found:
1878         if (ssif_dbg_probe) {
1879                 dev_dbg(&ssif_info->client->dev,
1880                        "%s: i2c_probe found device at i2c address %x\n",
1881                        __func__, client->addr);
1882         }
1883
1884         spin_lock_init(&ssif_info->lock);
1885         ssif_info->ssif_state = SSIF_NORMAL;
1886         timer_setup(&ssif_info->retry_timer, retry_timeout, 0);
1887         timer_setup(&ssif_info->watch_timer, watch_timeout, 0);
1888
1889         for (i = 0; i < SSIF_NUM_STATS; i++)
1890                 atomic_set(&ssif_info->stats[i], 0);
1891
1892         if (ssif_info->supports_pec)
1893                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1894
1895         ssif_info->handlers.owner = THIS_MODULE;
1896         ssif_info->handlers.start_processing = ssif_start_processing;
1897         ssif_info->handlers.shutdown = shutdown_ssif;
1898         ssif_info->handlers.get_smi_info = get_smi_info;
1899         ssif_info->handlers.sender = sender;
1900         ssif_info->handlers.request_events = request_events;
1901         ssif_info->handlers.set_need_watch = ssif_set_need_watch;
1902
1903         {
1904                 unsigned int thread_num;
1905
1906                 thread_num = ((i2c_adapter_id(ssif_info->client->adapter)
1907                                << 8) |
1908                               ssif_info->client->addr);
1909                 init_completion(&ssif_info->wake_thread);
1910                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1911                                                "kssif%4.4x", thread_num);
1912                 if (IS_ERR(ssif_info->thread)) {
1913                         rv = PTR_ERR(ssif_info->thread);
1914                         dev_notice(&ssif_info->client->dev,
1915                                    "Could not start kernel thread: error %d\n",
1916                                    rv);
1917                         goto out;
1918                 }
1919         }
1920
1921         dev_set_drvdata(&ssif_info->client->dev, ssif_info);
1922         rv = device_add_group(&ssif_info->client->dev,
1923                               &ipmi_ssif_dev_attr_group);
1924         if (rv) {
1925                 dev_err(&ssif_info->client->dev,
1926                         "Unable to add device attributes: error %d\n",
1927                         rv);
1928                 goto out;
1929         }
1930
1931         rv = ipmi_register_smi(&ssif_info->handlers,
1932                                ssif_info,
1933                                &ssif_info->client->dev,
1934                                slave_addr);
1935         if (rv) {
1936                 dev_err(&ssif_info->client->dev,
1937                         "Unable to register device: error %d\n", rv);
1938                 goto out_remove_attr;
1939         }
1940
1941  out:
1942         if (rv) {
1943                 if (addr_info)
1944                         addr_info->client = NULL;
1945
1946                 dev_err(&ssif_info->client->dev,
1947                         "Unable to start IPMI SSIF: %d\n", rv);
1948                 i2c_set_clientdata(client, NULL);
1949                 kfree(ssif_info);
1950         }
1951         kfree(resp);
1952         mutex_unlock(&ssif_infos_mutex);
1953         return rv;
1954
1955 out_remove_attr:
1956         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1957         dev_set_drvdata(&ssif_info->client->dev, NULL);
1958         goto out;
1959 }
1960
1961 static int new_ssif_client(int addr, char *adapter_name,
1962                            int debug, int slave_addr,
1963                            enum ipmi_addr_src addr_src,
1964                            struct device *dev)
1965 {
1966         struct ssif_addr_info *addr_info;
1967         int rv = 0;
1968
1969         mutex_lock(&ssif_infos_mutex);
1970         if (ssif_info_find(addr, adapter_name, false)) {
1971                 rv = -EEXIST;
1972                 goto out_unlock;
1973         }
1974
1975         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1976         if (!addr_info) {
1977                 rv = -ENOMEM;
1978                 goto out_unlock;
1979         }
1980
1981         if (adapter_name) {
1982                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1983                 if (!addr_info->adapter_name) {
1984                         kfree(addr_info);
1985                         rv = -ENOMEM;
1986                         goto out_unlock;
1987                 }
1988         }
1989
1990         strncpy(addr_info->binfo.type, DEVICE_NAME,
1991                 sizeof(addr_info->binfo.type));
1992         addr_info->binfo.addr = addr;
1993         addr_info->binfo.platform_data = addr_info;
1994         addr_info->debug = debug;
1995         addr_info->slave_addr = slave_addr;
1996         addr_info->addr_src = addr_src;
1997         addr_info->dev = dev;
1998
1999         if (dev)
2000                 dev_set_drvdata(dev, addr_info);
2001
2002         list_add_tail(&addr_info->link, &ssif_infos);
2003
2004         /* Address list will get it */
2005
2006 out_unlock:
2007         mutex_unlock(&ssif_infos_mutex);
2008         return rv;
2009 }
2010
2011 static void free_ssif_clients(void)
2012 {
2013         struct ssif_addr_info *info, *tmp;
2014
2015         mutex_lock(&ssif_infos_mutex);
2016         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
2017                 list_del(&info->link);
2018                 kfree(info->adapter_name);
2019                 kfree(info);
2020         }
2021         mutex_unlock(&ssif_infos_mutex);
2022 }
2023
2024 static unsigned short *ssif_address_list(void)
2025 {
2026         struct ssif_addr_info *info;
2027         unsigned int count = 0, i = 0;
2028         unsigned short *address_list;
2029
2030         list_for_each_entry(info, &ssif_infos, link)
2031                 count++;
2032
2033         address_list = kcalloc(count + 1, sizeof(*address_list),
2034                                GFP_KERNEL);
2035         if (!address_list)
2036                 return NULL;
2037
2038         list_for_each_entry(info, &ssif_infos, link) {
2039                 unsigned short addr = info->binfo.addr;
2040                 int j;
2041
2042                 for (j = 0; j < i; j++) {
2043                         if (address_list[j] == addr)
2044                                 /* Found a dup. */
2045                                 break;
2046                 }
2047                 if (j == i) /* Didn't find it in the list. */
2048                         address_list[i++] = addr;
2049         }
2050         address_list[i] = I2C_CLIENT_END;
2051
2052         return address_list;
2053 }
2054
2055 #ifdef CONFIG_ACPI
2056 static const struct acpi_device_id ssif_acpi_match[] = {
2057         { "IPI0001", 0 },
2058         { },
2059 };
2060 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
2061 #endif
2062
2063 #ifdef CONFIG_DMI
2064 static int dmi_ipmi_probe(struct platform_device *pdev)
2065 {
2066         u8 slave_addr = 0;
2067         u16 i2c_addr;
2068         int rv;
2069
2070         if (!ssif_trydmi)
2071                 return -ENODEV;
2072
2073         rv = device_property_read_u16(&pdev->dev, "i2c-addr", &i2c_addr);
2074         if (rv) {
2075                 dev_warn(&pdev->dev, "No i2c-addr property\n");
2076                 return -ENODEV;
2077         }
2078
2079         rv = device_property_read_u8(&pdev->dev, "slave-addr", &slave_addr);
2080         if (rv)
2081                 slave_addr = 0x20;
2082
2083         return new_ssif_client(i2c_addr, NULL, 0,
2084                                slave_addr, SI_SMBIOS, &pdev->dev);
2085 }
2086 #else
2087 static int dmi_ipmi_probe(struct platform_device *pdev)
2088 {
2089         return -ENODEV;
2090 }
2091 #endif
2092
2093 static const struct i2c_device_id ssif_id[] = {
2094         { DEVICE_NAME, 0 },
2095         { }
2096 };
2097 MODULE_DEVICE_TABLE(i2c, ssif_id);
2098
2099 static struct i2c_driver ssif_i2c_driver = {
2100         .class          = I2C_CLASS_HWMON,
2101         .driver         = {
2102                 .name                   = DEVICE_NAME
2103         },
2104         .probe          = ssif_probe,
2105         .remove         = ssif_remove,
2106         .alert          = ssif_alert,
2107         .id_table       = ssif_id,
2108         .detect         = ssif_detect
2109 };
2110
2111 static int ssif_platform_probe(struct platform_device *dev)
2112 {
2113         return dmi_ipmi_probe(dev);
2114 }
2115
2116 static int ssif_platform_remove(struct platform_device *dev)
2117 {
2118         struct ssif_addr_info *addr_info = dev_get_drvdata(&dev->dev);
2119
2120         if (!addr_info)
2121                 return 0;
2122
2123         mutex_lock(&ssif_infos_mutex);
2124         list_del(&addr_info->link);
2125         kfree(addr_info);
2126         mutex_unlock(&ssif_infos_mutex);
2127         return 0;
2128 }
2129
2130 static const struct platform_device_id ssif_plat_ids[] = {
2131     { "dmi-ipmi-ssif", 0 },
2132     { }
2133 };
2134
2135 static struct platform_driver ipmi_driver = {
2136         .driver = {
2137                 .name = DEVICE_NAME,
2138         },
2139         .probe          = ssif_platform_probe,
2140         .remove         = ssif_platform_remove,
2141         .id_table       = ssif_plat_ids
2142 };
2143
2144 static int init_ipmi_ssif(void)
2145 {
2146         int i;
2147         int rv;
2148
2149         if (initialized)
2150                 return 0;
2151
2152         pr_info("IPMI SSIF Interface driver\n");
2153
2154         /* build list for i2c from addr list */
2155         for (i = 0; i < num_addrs; i++) {
2156                 rv = new_ssif_client(addr[i], adapter_name[i],
2157                                      dbg[i], slave_addrs[i],
2158                                      SI_HARDCODED, NULL);
2159                 if (rv)
2160                         pr_err("Couldn't add hardcoded device at addr 0x%x\n",
2161                                addr[i]);
2162         }
2163
2164         if (ssif_tryacpi)
2165                 ssif_i2c_driver.driver.acpi_match_table =
2166                         ACPI_PTR(ssif_acpi_match);
2167
2168         if (ssif_trydmi) {
2169                 rv = platform_driver_register(&ipmi_driver);
2170                 if (rv)
2171                         pr_err("Unable to register driver: %d\n", rv);
2172                 else
2173                         platform_registered = true;
2174         }
2175
2176         ssif_i2c_driver.address_list = ssif_address_list();
2177
2178         rv = i2c_add_driver(&ssif_i2c_driver);
2179         if (!rv)
2180                 initialized = true;
2181
2182         return rv;
2183 }
2184 module_init(init_ipmi_ssif);
2185
2186 static void cleanup_ipmi_ssif(void)
2187 {
2188         if (!initialized)
2189                 return;
2190
2191         initialized = false;
2192
2193         i2c_del_driver(&ssif_i2c_driver);
2194
2195         kfree(ssif_i2c_driver.address_list);
2196
2197         if (ssif_trydmi && platform_registered)
2198                 platform_driver_unregister(&ipmi_driver);
2199
2200         free_ssif_clients();
2201 }
2202 module_exit(cleanup_ipmi_ssif);
2203
2204 MODULE_ALIAS("platform:dmi-ipmi-ssif");
2205 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2206 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2207 MODULE_LICENSE("GPL");