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 /*
  26  * TODO: Figure out how to use SMB alerts.  This will require a new
  27  * interface into the I2C driver, I believe.
  28  */
  29
  30 #define pr_fmt(fmt) "ipmi_ssif: " fmt
  31 #define dev_fmt(fmt) "ipmi_ssif: " fmt
  32
  33 #if defined(MODVERSIONS)
  34 #include <linux/modversions.h>
  35 #endif
  36
  37 #include <linux/module.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/sched.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/timer.h>
  42 #include <linux/delay.h>
  43 #include <linux/errno.h>
  44 #include <linux/spinlock.h>
  45 #include <linux/slab.h>
  46 #include <linux/list.h>
  47 #include <linux/i2c.h>
  48 #include <linux/ipmi_smi.h>
  49 #include <linux/init.h>
  50 #include <linux/dmi.h>
  51 #include <linux/kthread.h>
  52 #include <linux/acpi.h>
  53 #include <linux/ctype.h>
  54 #include <linux/time64.h>
  55 #include "ipmi_dmi.h"
  56
  57 #define DEVICE_NAME "ipmi_ssif"
  58
  59 #define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD      0x57
  60
  61 #define SSIF_IPMI_REQUEST                       2
  62 #define SSIF_IPMI_MULTI_PART_REQUEST_START      6
  63 #define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE     7
  64 #define SSIF_IPMI_MULTI_PART_REQUEST_END        8
  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 /*
  94  * Timeout for the watch, only used for get flag timer.
  95  */
  96 #define SSIF_WATCH_MSG_TIMEOUT          msecs_to_jiffies(10)
  97 #define SSIF_WATCH_WATCHDOG_TIMEOUT     msecs_to_jiffies(250)
  98
  99 enum ssif_intf_state {
 100         SSIF_NORMAL,
 101         SSIF_GETTING_FLAGS,
 102         SSIF_GETTING_EVENTS,
 103         SSIF_CLEARING_FLAGS,
 104         SSIF_GETTING_MESSAGES,
 105         /* FIXME - add watchdog stuff. */
 106 };
 107
 108 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
 109                           && (ssif)->curr_msg == NULL)
 110
 111 /*
 112  * Indexes into stats[] in ssif_info below.
 113  */
 114 enum ssif_stat_indexes {
 115         /* Number of total messages sent. */
 116         SSIF_STAT_sent_messages = 0,
 117
 118         /*
 119          * Number of message parts sent.  Messages may be broken into
 120          * parts if they are long.
 121          */
 122         SSIF_STAT_sent_messages_parts,
 123
 124         /*
 125          * Number of time a message was retried.
 126          */
 127         SSIF_STAT_send_retries,
 128
 129         /*
 130          * Number of times the send of a message failed.
 131          */
 132         SSIF_STAT_send_errors,
 133
 134         /*
 135          * Number of message responses received.
 136          */
 137         SSIF_STAT_received_messages,
 138
 139         /*
 140          * Number of message fragments received.
 141          */
 142         SSIF_STAT_received_message_parts,
 143
 144         /*
 145          * Number of times the receive of a message was retried.
 146          */
 147         SSIF_STAT_receive_retries,
 148
 149         /*
 150          * Number of errors receiving messages.
 151          */
 152         SSIF_STAT_receive_errors,
 153
 154         /*
 155          * Number of times a flag fetch was requested.
 156          */
 157         SSIF_STAT_flag_fetches,
 158
 159         /*
 160          * Number of times the hardware didn't follow the state machine.
 161          */
 162         SSIF_STAT_hosed,
 163
 164         /*
 165          * Number of received events.
 166          */
 167         SSIF_STAT_events,
 168
 169         /* Number of asyncronous messages received. */
 170         SSIF_STAT_incoming_messages,
 171
 172         /* Number of watchdog pretimeouts. */
 173         SSIF_STAT_watchdog_pretimeouts,
 174
 175         /* Number of alers received. */
 176         SSIF_STAT_alerts,
 177
 178         /* Always add statistics before this value, it must be last. */
 179         SSIF_NUM_STATS
 180 };
 181
 182 struct ssif_addr_info {
 183         struct i2c_board_info binfo;
 184         char *adapter_name;
 185         int debug;
 186         int slave_addr;
 187         enum ipmi_addr_src addr_src;
 188         union ipmi_smi_info_union addr_info;
 189         struct device *dev;
 190         struct i2c_client *client;
 191
 192         struct i2c_client *added_client;
 193
 194         struct mutex clients_mutex;
 195         struct list_head clients;
 196
 197         struct list_head link;
 198 };
 199
 200 struct ssif_info;
 201
 202 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
 203                              unsigned char *data, unsigned int len);
 204
 205 struct ssif_info {
 206         struct ipmi_smi     *intf;
 207         spinlock_t          lock;
 208         struct ipmi_smi_msg *waiting_msg;
 209         struct ipmi_smi_msg *curr_msg;
 210         enum ssif_intf_state ssif_state;
 211         unsigned long       ssif_debug;
 212
 213         struct ipmi_smi_handlers handlers;
 214
 215         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
 216         union ipmi_smi_info_union addr_info;
 217
 218         /*
 219          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 220          * is set to hold the flags until we are done handling everything
 221          * from the flags.
 222          */
 223 #define RECEIVE_MSG_AVAIL       0x01
 224 #define EVENT_MSG_BUFFER_FULL   0x02
 225 #define WDT_PRE_TIMEOUT_INT     0x08
 226         unsigned char       msg_flags;
 227
 228         u8                  global_enables;
 229         bool                has_event_buffer;
 230         bool                supports_alert;
 231
 232         /*
 233          * Used to tell what we should do with alerts.  If we are
 234          * waiting on a response, read the data immediately.
 235          */
 236         bool                got_alert;
 237         bool                waiting_alert;
 238
 239         /*
 240          * If set to true, this will request events the next time the
 241          * state machine is idle.
 242          */
 243         bool                req_events;
 244
 245         /*
 246          * If set to true, this will request flags the next time the
 247          * state machine is idle.
 248          */
 249         bool                req_flags;
 250
 251         /*
 252          * Used to perform timer operations when run-to-completion
 253          * mode is on.  This is a countdown timer.
 254          */
 255         int                 rtc_us_timer;
 256
 257         /* Used for sending/receiving data.  +1 for the length. */
 258         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
 259         unsigned int  data_len;
 260
 261         /* Temp receive buffer, gets copied into data. */
 262         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
 263
 264         struct i2c_client *client;
 265         ssif_i2c_done done_handler;
 266
 267         /* Thread interface handling */
 268         struct task_struct *thread;
 269         struct completion wake_thread;
 270         bool stopping;
 271         int i2c_read_write;
 272         int i2c_command;
 273         unsigned char *i2c_data;
 274         unsigned int i2c_size;
 275
 276         struct timer_list retry_timer;
 277         int retries_left;
 278
 279         long watch_timeout;             /* Timeout for flags check, 0 if off. */
 280         struct timer_list watch_timer;  /* Flag fetch timer. */
 281
 282         /* Info from SSIF cmd */
 283         unsigned char max_xmit_msg_size;
 284         unsigned char max_recv_msg_size;
 285         bool cmd8_works; /* See test_multipart_messages() for details. */
 286         unsigned int  multi_support;
 287         int           supports_pec;
 288
 289 #define SSIF_NO_MULTI           0
 290 #define SSIF_MULTI_2_PART       1
 291 #define SSIF_MULTI_n_PART       2
 292         unsigned char *multi_data;
 293         unsigned int  multi_len;
 294         unsigned int  multi_pos;
 295
 296         atomic_t stats[SSIF_NUM_STATS];
 297 };
 298
 299 #define ssif_inc_stat(ssif, stat) \
 300         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
 301 #define ssif_get_stat(ssif, stat) \
 302         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
 303
 304 static bool initialized;
 305 static bool platform_registered;
 306
 307 static void return_hosed_msg(struct ssif_info *ssif_info,
 308                              struct ipmi_smi_msg *msg);
 309 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
 310 static int start_send(struct ssif_info *ssif_info,
 311                       unsigned char   *data,
 312                       unsigned int    len);
 313
 314 static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
 315                                           unsigned long *flags)
 316 {
 317         spin_lock_irqsave(&ssif_info->lock, *flags);
 318         return flags;
 319 }
 320
 321 static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
 322                                   unsigned long *flags)
 323 {
 324         spin_unlock_irqrestore(&ssif_info->lock, *flags);
 325 }
 326
 327 static void deliver_recv_msg(struct ssif_info *ssif_info,
 328                              struct ipmi_smi_msg *msg)
 329 {
 330         if (msg->rsp_size < 0) {
 331                 return_hosed_msg(ssif_info, msg);
 332                 dev_err(&ssif_info->client->dev,
 333                         "%s: Malformed message: rsp_size = %d\n",
 334                        __func__, msg->rsp_size);
 335         } else {
 336                 ipmi_smi_msg_received(ssif_info->intf, msg);
 337         }
 338 }
 339
 340 static void return_hosed_msg(struct ssif_info *ssif_info,
 341                              struct ipmi_smi_msg *msg)
 342 {
 343         ssif_inc_stat(ssif_info, hosed);
 344
 345         /* Make it a response */
 346         msg->rsp[0] = msg->data[0] | 4;
 347         msg->rsp[1] = msg->data[1];
 348         msg->rsp[2] = 0xFF; /* Unknown error. */
 349         msg->rsp_size = 3;
 350
 351         deliver_recv_msg(ssif_info, msg);
 352 }
 353
 354 /*
 355  * Must be called with the message lock held.  This will release the
 356  * message lock.  Note that the caller will check SSIF_IDLE and start a
 357  * new operation, so there is no need to check for new messages to
 358  * start in here.
 359  */
 360 static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
 361 {
 362         unsigned char msg[3];
 363
 364         ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
 365         ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
 366         ipmi_ssif_unlock_cond(ssif_info, flags);
 367
 368         /* Make sure the watchdog pre-timeout flag is not set at startup. */
 369         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 370         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
 371         msg[2] = WDT_PRE_TIMEOUT_INT;
 372
 373         if (start_send(ssif_info, msg, 3) != 0) {
 374                 /* Error, just go to normal state. */
 375                 ssif_info->ssif_state = SSIF_NORMAL;
 376         }
 377 }
 378
 379 static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 380 {
 381         unsigned char mb[2];
 382
 383         ssif_info->req_flags = false;
 384         ssif_info->ssif_state = SSIF_GETTING_FLAGS;
 385         ipmi_ssif_unlock_cond(ssif_info, flags);
 386
 387         mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
 388         mb[1] = IPMI_GET_MSG_FLAGS_CMD;
 389         if (start_send(ssif_info, mb, 2) != 0)
 390                 ssif_info->ssif_state = SSIF_NORMAL;
 391 }
 392
 393 static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
 394                              struct ipmi_smi_msg *msg)
 395 {
 396         if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
 397                 unsigned long oflags;
 398
 399                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 400                 ssif_info->curr_msg = NULL;
 401                 ssif_info->ssif_state = SSIF_NORMAL;
 402                 ipmi_ssif_unlock_cond(ssif_info, flags);
 403                 ipmi_free_smi_msg(msg);
 404         }
 405 }
 406
 407 static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 408 {
 409         struct ipmi_smi_msg *msg;
 410
 411         ssif_info->req_events = false;
 412
 413         msg = ipmi_alloc_smi_msg();
 414         if (!msg) {
 415                 ssif_info->ssif_state = SSIF_NORMAL;
 416                 ipmi_ssif_unlock_cond(ssif_info, flags);
 417                 return;
 418         }
 419
 420         ssif_info->curr_msg = msg;
 421         ssif_info->ssif_state = SSIF_GETTING_EVENTS;
 422         ipmi_ssif_unlock_cond(ssif_info, flags);
 423
 424         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 425         msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
 426         msg->data_size = 2;
 427
 428         check_start_send(ssif_info, flags, msg);
 429 }
 430
 431 static void start_recv_msg_fetch(struct ssif_info *ssif_info,
 432                                  unsigned long *flags)
 433 {
 434         struct ipmi_smi_msg *msg;
 435
 436         msg = ipmi_alloc_smi_msg();
 437         if (!msg) {
 438                 ssif_info->ssif_state = SSIF_NORMAL;
 439                 ipmi_ssif_unlock_cond(ssif_info, flags);
 440                 return;
 441         }
 442
 443         ssif_info->curr_msg = msg;
 444         ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
 445         ipmi_ssif_unlock_cond(ssif_info, flags);
 446
 447         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 448         msg->data[1] = IPMI_GET_MSG_CMD;
 449         msg->data_size = 2;
 450
 451         check_start_send(ssif_info, flags, msg);
 452 }
 453
 454 /*
 455  * Must be called with the message lock held.  This will release the
 456  * message lock.  Note that the caller will check SSIF_IDLE and start a
 457  * new operation, so there is no need to check for new messages to
 458  * start in here.
 459  */
 460 static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
 461 {
 462         if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
 463                 /* Watchdog pre-timeout */
 464                 ssif_inc_stat(ssif_info, watchdog_pretimeouts);
 465                 start_clear_flags(ssif_info, flags);
 466                 ipmi_smi_watchdog_pretimeout(ssif_info->intf);
 467         } else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
 468                 /* Messages available. */
 469                 start_recv_msg_fetch(ssif_info, flags);
 470         else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
 471                 /* Events available. */
 472                 start_event_fetch(ssif_info, flags);
 473         else {
 474                 ssif_info->ssif_state = SSIF_NORMAL;
 475                 ipmi_ssif_unlock_cond(ssif_info, flags);
 476         }
 477 }
 478
 479 static int ipmi_ssif_thread(void *data)
 480 {
 481         struct ssif_info *ssif_info = data;
 482
 483         while (!kthread_should_stop()) {
 484                 int result;
 485
 486                 /* Wait for something to do */
 487                 result = wait_for_completion_interruptible(
 488                                                 &ssif_info->wake_thread);
 489                 if (ssif_info->stopping)
 490                         break;
 491                 if (result == -ERESTARTSYS)
 492                         continue;
 493                 init_completion(&ssif_info->wake_thread);
 494
 495                 if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
 496                         result = i2c_smbus_write_block_data(
 497                                 ssif_info->client, ssif_info->i2c_command,
 498                                 ssif_info->i2c_data[0],
 499                                 ssif_info->i2c_data + 1);
 500                         ssif_info->done_handler(ssif_info, result, NULL, 0);
 501                 } else {
 502                         result = i2c_smbus_read_block_data(
 503                                 ssif_info->client, ssif_info->i2c_command,
 504                                 ssif_info->i2c_data);
 505                         if (result < 0)
 506                                 ssif_info->done_handler(ssif_info, result,
 507                                                         NULL, 0);
 508                         else
 509                                 ssif_info->done_handler(ssif_info, 0,
 510                                                         ssif_info->i2c_data,
 511                                                         result);
 512                 }
 513         }
 514
 515         return 0;
 516 }
 517
 518 static int ssif_i2c_send(struct ssif_info *ssif_info,
 519                         ssif_i2c_done handler,
 520                         int read_write, int command,
 521                         unsigned char *data, unsigned int size)
 522 {
 523         ssif_info->done_handler = handler;
 524
 525         ssif_info->i2c_read_write = read_write;
 526         ssif_info->i2c_command = command;
 527         ssif_info->i2c_data = data;
 528         ssif_info->i2c_size = size;
 529         complete(&ssif_info->wake_thread);
 530         return 0;
 531 }
 532
 533
 534 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 535                              unsigned char *data, unsigned int len);
 536
 537 static void start_get(struct ssif_info *ssif_info)
 538 {
 539         int rv;
 540
 541         ssif_info->rtc_us_timer = 0;
 542         ssif_info->multi_pos = 0;
 543
 544         rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 545                           SSIF_IPMI_RESPONSE,
 546                           ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 547         if (rv < 0) {
 548                 /* request failed, just return the error. */
 549                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 550                         dev_dbg(&ssif_info->client->dev,
 551                                 "Error from i2c_non_blocking_op(5)\n");
 552
 553                 msg_done_handler(ssif_info, -EIO, NULL, 0);
 554         }
 555 }
 556
 557 static void retry_timeout(struct timer_list *t)
 558 {
 559         struct ssif_info *ssif_info = from_timer(ssif_info, t, retry_timer);
 560         unsigned long oflags, *flags;
 561         bool waiting;
 562
 563         if (ssif_info->stopping)
 564                 return;
 565
 566         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 567         waiting = ssif_info->waiting_alert;
 568         ssif_info->waiting_alert = false;
 569         ipmi_ssif_unlock_cond(ssif_info, flags);
 570
 571         if (waiting)
 572                 start_get(ssif_info);
 573 }
 574
 575 static void watch_timeout(struct timer_list *t)
 576 {
 577         struct ssif_info *ssif_info = from_timer(ssif_info, t, watch_timer);
 578         unsigned long oflags, *flags;
 579
 580         if (ssif_info->stopping)
 581                 return;
 582
 583         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 584         if (ssif_info->watch_timeout) {
 585                 mod_timer(&ssif_info->watch_timer,
 586                           jiffies + ssif_info->watch_timeout);
 587                 if (SSIF_IDLE(ssif_info)) {
 588                         start_flag_fetch(ssif_info, flags); /* Releases lock */
 589                         return;
 590                 }
 591                 ssif_info->req_flags = true;
 592         }
 593         ipmi_ssif_unlock_cond(ssif_info, flags);
 594 }
 595
 596 static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
 597                        unsigned int data)
 598 {
 599         struct ssif_info *ssif_info = i2c_get_clientdata(client);
 600         unsigned long oflags, *flags;
 601         bool do_get = false;
 602
 603         if (type != I2C_PROTOCOL_SMBUS_ALERT)
 604                 return;
 605
 606         ssif_inc_stat(ssif_info, alerts);
 607
 608         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 609         if (ssif_info->waiting_alert) {
 610                 ssif_info->waiting_alert = false;
 611                 del_timer(&ssif_info->retry_timer);
 612                 do_get = true;
 613         } else if (ssif_info->curr_msg) {
 614                 ssif_info->got_alert = true;
 615         }
 616         ipmi_ssif_unlock_cond(ssif_info, flags);
 617         if (do_get)
 618                 start_get(ssif_info);
 619 }
 620
 621 static int start_resend(struct ssif_info *ssif_info);
 622
 623 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 624                              unsigned char *data, unsigned int len)
 625 {
 626         struct ipmi_smi_msg *msg;
 627         unsigned long oflags, *flags;
 628         int rv;
 629
 630         /*
 631          * We are single-threaded here, so no need for a lock until we
 632          * start messing with driver states or the queues.
 633          */
 634
 635         if (result < 0) {
 636                 ssif_info->retries_left--;
 637                 if (ssif_info->retries_left > 0) {
 638                         ssif_inc_stat(ssif_info, receive_retries);
 639
 640                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 641                         ssif_info->waiting_alert = true;
 642                         ssif_info->rtc_us_timer = SSIF_MSG_USEC;
 643                         if (!ssif_info->stopping)
 644                                 mod_timer(&ssif_info->retry_timer,
 645                                           jiffies + SSIF_MSG_JIFFIES);
 646                         ipmi_ssif_unlock_cond(ssif_info, flags);
 647                         return;
 648                 }
 649
 650                 ssif_inc_stat(ssif_info, receive_errors);
 651
 652                 if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 653                         dev_dbg(&ssif_info->client->dev,
 654                                 "%s: Error %d\n", __func__, result);
 655                 len = 0;
 656                 goto continue_op;
 657         }
 658
 659         if ((len > 1) && (ssif_info->multi_pos == 0)
 660                                 && (data[0] == 0x00) && (data[1] == 0x01)) {
 661                 /* Start of multi-part read.  Start the next transaction. */
 662                 int i;
 663
 664                 ssif_inc_stat(ssif_info, received_message_parts);
 665
 666                 /* Remove the multi-part read marker. */
 667                 len -= 2;
 668                 data += 2;
 669                 for (i = 0; i < len; i++)
 670                         ssif_info->data[i] = data[i];
 671                 ssif_info->multi_len = len;
 672                 ssif_info->multi_pos = 1;
 673
 674                 rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 675                                   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 676                                   ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 677                 if (rv < 0) {
 678                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 679                                 dev_dbg(&ssif_info->client->dev,
 680                                         "Error from i2c_non_blocking_op(1)\n");
 681
 682                         result = -EIO;
 683                 } else
 684                         return;
 685         } else if (ssif_info->multi_pos) {
 686                 /* Middle of multi-part read.  Start the next transaction. */
 687                 int i;
 688                 unsigned char blocknum;
 689
 690                 if (len == 0) {
 691                         result = -EIO;
 692                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 693                                 dev_dbg(&ssif_info->client->dev,
 694                                         "Middle message with no data\n");
 695
 696                         goto continue_op;
 697                 }
 698
 699                 blocknum = data[0];
 700                 len--;
 701                 data++;
 702
 703                 if (blocknum != 0xff && len != 31) {
 704                     /* All blocks but the last must have 31 data bytes. */
 705                         result = -EIO;
 706                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 707                                 dev_dbg(&ssif_info->client->dev,
 708                                         "Received middle message <31\n");
 709
 710                         goto continue_op;
 711                 }
 712
 713                 if (ssif_info->multi_len + len > IPMI_MAX_MSG_LENGTH) {
 714                         /* Received message too big, abort the operation. */
 715                         result = -E2BIG;
 716                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 717                                 dev_dbg(&ssif_info->client->dev,
 718                                         "Received message too big\n");
 719
 720                         goto continue_op;
 721                 }
 722
 723                 for (i = 0; i < len; i++)
 724                         ssif_info->data[i + ssif_info->multi_len] = data[i];
 725                 ssif_info->multi_len += len;
 726                 if (blocknum == 0xff) {
 727                         /* End of read */
 728                         len = ssif_info->multi_len;
 729                         data = ssif_info->data;
 730                 } else if (blocknum + 1 != ssif_info->multi_pos) {
 731                         /*
 732                          * Out of sequence block, just abort.  Block
 733                          * numbers start at zero for the second block,
 734                          * but multi_pos starts at one, so the +1.
 735                          */
 736                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 737                                 dev_dbg(&ssif_info->client->dev,
 738                                         "Received message out of sequence, expected %u, got %u\n",
 739                                         ssif_info->multi_pos - 1, blocknum);
 740                         result = -EIO;
 741                 } else {
 742                         ssif_inc_stat(ssif_info, received_message_parts);
 743
 744                         ssif_info->multi_pos++;
 745
 746                         rv = ssif_i2c_send(ssif_info, msg_done_handler,
 747                                            I2C_SMBUS_READ,
 748                                            SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 749                                            ssif_info->recv,
 750                                            I2C_SMBUS_BLOCK_DATA);
 751                         if (rv < 0) {
 752                                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 753                                         dev_dbg(&ssif_info->client->dev,
 754                                                 "Error from ssif_i2c_send\n");
 755
 756                                 result = -EIO;
 757                         } else
 758                                 return;
 759                 }
 760         }
 761
 762  continue_op:
 763         if (result < 0) {
 764                 ssif_inc_stat(ssif_info, receive_errors);
 765         } else {
 766                 ssif_inc_stat(ssif_info, received_messages);
 767                 ssif_inc_stat(ssif_info, received_message_parts);
 768         }
 769
 770         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 771                 dev_dbg(&ssif_info->client->dev,
 772                         "DONE 1: state = %d, result=%d\n",
 773                         ssif_info->ssif_state, result);
 774
 775         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 776         msg = ssif_info->curr_msg;
 777         if (msg) {
 778                 msg->rsp_size = len;
 779                 if (msg->rsp_size > IPMI_MAX_MSG_LENGTH)
 780                         msg->rsp_size = IPMI_MAX_MSG_LENGTH;
 781                 memcpy(msg->rsp, data, msg->rsp_size);
 782                 ssif_info->curr_msg = NULL;
 783         }
 784
 785         switch (ssif_info->ssif_state) {
 786         case SSIF_NORMAL:
 787                 ipmi_ssif_unlock_cond(ssif_info, flags);
 788                 if (!msg)
 789                         break;
 790
 791                 if (result < 0)
 792                         return_hosed_msg(ssif_info, msg);
 793                 else
 794                         deliver_recv_msg(ssif_info, msg);
 795                 break;
 796
 797         case SSIF_GETTING_FLAGS:
 798                 /* We got the flags from the SSIF, now handle them. */
 799                 if ((result < 0) || (len < 4) || (data[2] != 0)) {
 800                         /*
 801                          * Error fetching flags, or invalid length,
 802                          * just give up for now.
 803                          */
 804                         ssif_info->ssif_state = SSIF_NORMAL;
 805                         ipmi_ssif_unlock_cond(ssif_info, flags);
 806                         dev_warn(&ssif_info->client->dev,
 807                                  "Error getting flags: %d %d, %x\n",
 808                                  result, len, (len >= 3) ? data[2] : 0);
 809                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 810                            || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
 811                         /*
 812                          * Don't abort here, maybe it was a queued
 813                          * response to a previous command.
 814                          */
 815                         ipmi_ssif_unlock_cond(ssif_info, flags);
 816                         dev_warn(&ssif_info->client->dev,
 817                                  "Invalid response getting flags: %x %x\n",
 818                                  data[0], data[1]);
 819                 } else {
 820                         ssif_inc_stat(ssif_info, flag_fetches);
 821                         ssif_info->msg_flags = data[3];
 822                         handle_flags(ssif_info, flags);
 823                 }
 824                 break;
 825
 826         case SSIF_CLEARING_FLAGS:
 827                 /* We cleared the flags. */
 828                 if ((result < 0) || (len < 3) || (data[2] != 0)) {
 829                         /* Error clearing flags */
 830                         dev_warn(&ssif_info->client->dev,
 831                                  "Error clearing flags: %d %d, %x\n",
 832                                  result, len, (len >= 3) ? data[2] : 0);
 833                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 834                            || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
 835                         dev_warn(&ssif_info->client->dev,
 836                                  "Invalid response clearing flags: %x %x\n",
 837                                  data[0], data[1]);
 838                 }
 839                 ssif_info->ssif_state = SSIF_NORMAL;
 840                 ipmi_ssif_unlock_cond(ssif_info, flags);
 841                 break;
 842
 843         case SSIF_GETTING_EVENTS:
 844                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 845                         /* Error getting event, probably done. */
 846                         msg->done(msg);
 847
 848                         /* Take off the event flag. */
 849                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 850                         handle_flags(ssif_info, flags);
 851                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 852                            || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
 853                         dev_warn(&ssif_info->client->dev,
 854                                  "Invalid response getting events: %x %x\n",
 855                                  msg->rsp[0], msg->rsp[1]);
 856                         msg->done(msg);
 857                         /* Take off the event flag. */
 858                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 859                         handle_flags(ssif_info, flags);
 860                 } else {
 861                         handle_flags(ssif_info, flags);
 862                         ssif_inc_stat(ssif_info, events);
 863                         deliver_recv_msg(ssif_info, msg);
 864                 }
 865                 break;
 866
 867         case SSIF_GETTING_MESSAGES:
 868                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 869                         /* Error getting event, probably done. */
 870                         msg->done(msg);
 871
 872                         /* Take off the msg flag. */
 873                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 874                         handle_flags(ssif_info, flags);
 875                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 876                            || msg->rsp[1] != IPMI_GET_MSG_CMD) {
 877                         dev_warn(&ssif_info->client->dev,
 878                                  "Invalid response clearing flags: %x %x\n",
 879                                  msg->rsp[0], msg->rsp[1]);
 880                         msg->done(msg);
 881
 882                         /* Take off the msg flag. */
 883                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 884                         handle_flags(ssif_info, flags);
 885                 } else {
 886                         ssif_inc_stat(ssif_info, incoming_messages);
 887                         handle_flags(ssif_info, flags);
 888                         deliver_recv_msg(ssif_info, msg);
 889                 }
 890                 break;
 891         }
 892
 893         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 894         if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
 895                 if (ssif_info->req_events)
 896                         start_event_fetch(ssif_info, flags);
 897                 else if (ssif_info->req_flags)
 898                         start_flag_fetch(ssif_info, flags);
 899                 else
 900                         start_next_msg(ssif_info, flags);
 901         } else
 902                 ipmi_ssif_unlock_cond(ssif_info, flags);
 903
 904         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 905                 dev_dbg(&ssif_info->client->dev,
 906                         "DONE 2: state = %d.\n", ssif_info->ssif_state);
 907 }
 908
 909 static void msg_written_handler(struct ssif_info *ssif_info, int result,
 910                                 unsigned char *data, unsigned int len)
 911 {
 912         int rv;
 913
 914         /* We are single-threaded here, so no need for a lock. */
 915         if (result < 0) {
 916                 ssif_info->retries_left--;
 917                 if (ssif_info->retries_left > 0) {
 918                         if (!start_resend(ssif_info)) {
 919                                 ssif_inc_stat(ssif_info, send_retries);
 920                                 return;
 921                         }
 922                         /* request failed, just return the error. */
 923                         ssif_inc_stat(ssif_info, send_errors);
 924
 925                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 926                                 dev_dbg(&ssif_info->client->dev,
 927                                         "%s: Out of retries\n", __func__);
 928                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 929                         return;
 930                 }
 931
 932                 ssif_inc_stat(ssif_info, send_errors);
 933
 934                 /*
 935                  * Got an error on transmit, let the done routine
 936                  * handle it.
 937                  */
 938                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 939                         dev_dbg(&ssif_info->client->dev,
 940                                 "%s: Error  %d\n", __func__, result);
 941
 942                 msg_done_handler(ssif_info, result, NULL, 0);
 943                 return;
 944         }
 945
 946         if (ssif_info->multi_data) {
 947                 /*
 948                  * In the middle of a multi-data write.  See the comment
 949                  * in the SSIF_MULTI_n_PART case in the probe function
 950                  * for details on the intricacies of this.
 951                  */
 952                 int left, to_write;
 953                 unsigned char *data_to_send;
 954                 unsigned char cmd;
 955
 956                 ssif_inc_stat(ssif_info, sent_messages_parts);
 957
 958                 left = ssif_info->multi_len - ssif_info->multi_pos;
 959                 to_write = left;
 960                 if (to_write > 32)
 961                         to_write = 32;
 962                 /* Length byte. */
 963                 ssif_info->multi_data[ssif_info->multi_pos] = to_write;
 964                 data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
 965                 ssif_info->multi_pos += to_write;
 966                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE;
 967                 if (ssif_info->cmd8_works) {
 968                         if (left == to_write) {
 969                                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_END;
 970                                 ssif_info->multi_data = NULL;
 971                         }
 972                 } else if (to_write < 32) {
 973                         ssif_info->multi_data = NULL;
 974                 }
 975
 976                 rv = ssif_i2c_send(ssif_info, msg_written_handler,
 977                                    I2C_SMBUS_WRITE, cmd,
 978                                    data_to_send, I2C_SMBUS_BLOCK_DATA);
 979                 if (rv < 0) {
 980                         /* request failed, just return the error. */
 981                         ssif_inc_stat(ssif_info, send_errors);
 982
 983                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 984                                 dev_dbg(&ssif_info->client->dev,
 985                                         "Error from i2c_non_blocking_op(3)\n");
 986                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 987                 }
 988         } else {
 989                 /* Ready to request the result. */
 990                 unsigned long oflags, *flags;
 991
 992                 ssif_inc_stat(ssif_info, sent_messages);
 993                 ssif_inc_stat(ssif_info, sent_messages_parts);
 994
 995                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 996                 if (ssif_info->got_alert) {
 997                         /* The result is already ready, just start it. */
 998                         ssif_info->got_alert = false;
 999                         ipmi_ssif_unlock_cond(ssif_info, flags);
1000                         start_get(ssif_info);
1001                 } else {
1002                         /* Wait a jiffie then request the next message */
1003                         ssif_info->waiting_alert = true;
1004                         ssif_info->retries_left = SSIF_RECV_RETRIES;
1005                         ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
1006                         if (!ssif_info->stopping)
1007                                 mod_timer(&ssif_info->retry_timer,
1008                                           jiffies + SSIF_MSG_PART_JIFFIES);
1009                         ipmi_ssif_unlock_cond(ssif_info, flags);
1010                 }
1011         }
1012 }
1013
1014 static int start_resend(struct ssif_info *ssif_info)
1015 {
1016         int rv;
1017         int command;
1018
1019         ssif_info->got_alert = false;
1020
1021         if (ssif_info->data_len > 32) {
1022                 command = SSIF_IPMI_MULTI_PART_REQUEST_START;
1023                 ssif_info->multi_data = ssif_info->data;
1024                 ssif_info->multi_len = ssif_info->data_len;
1025                 /*
1026                  * Subtle thing, this is 32, not 33, because we will
1027                  * overwrite the thing at position 32 (which was just
1028                  * transmitted) with the new length.
1029                  */
1030                 ssif_info->multi_pos = 32;
1031                 ssif_info->data[0] = 32;
1032         } else {
1033                 ssif_info->multi_data = NULL;
1034                 command = SSIF_IPMI_REQUEST;
1035                 ssif_info->data[0] = ssif_info->data_len;
1036         }
1037
1038         rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
1039                           command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
1040         if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
1041                 dev_dbg(&ssif_info->client->dev,
1042                         "Error from i2c_non_blocking_op(4)\n");
1043         return rv;
1044 }
1045
1046 static int start_send(struct ssif_info *ssif_info,
1047                       unsigned char   *data,
1048                       unsigned int    len)
1049 {
1050         if (len > IPMI_MAX_MSG_LENGTH)
1051                 return -E2BIG;
1052         if (len > ssif_info->max_xmit_msg_size)
1053                 return -E2BIG;
1054
1055         ssif_info->retries_left = SSIF_SEND_RETRIES;
1056         memcpy(ssif_info->data + 1, data, len);
1057         ssif_info->data_len = len;
1058         return start_resend(ssif_info);
1059 }
1060
1061 /* Must be called with the message lock held. */
1062 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
1063 {
1064         struct ipmi_smi_msg *msg;
1065         unsigned long oflags;
1066
1067  restart:
1068         if (!SSIF_IDLE(ssif_info)) {
1069                 ipmi_ssif_unlock_cond(ssif_info, flags);
1070                 return;
1071         }
1072
1073         if (!ssif_info->waiting_msg) {
1074                 ssif_info->curr_msg = NULL;
1075                 ipmi_ssif_unlock_cond(ssif_info, flags);
1076         } else {
1077                 int rv;
1078
1079                 ssif_info->curr_msg = ssif_info->waiting_msg;
1080                 ssif_info->waiting_msg = NULL;
1081                 ipmi_ssif_unlock_cond(ssif_info, flags);
1082                 rv = start_send(ssif_info,
1083                                 ssif_info->curr_msg->data,
1084                                 ssif_info->curr_msg->data_size);
1085                 if (rv) {
1086                         msg = ssif_info->curr_msg;
1087                         ssif_info->curr_msg = NULL;
1088                         return_hosed_msg(ssif_info, msg);
1089                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1090                         goto restart;
1091                 }
1092         }
1093 }
1094
1095 static void sender(void                *send_info,
1096                    struct ipmi_smi_msg *msg)
1097 {
1098         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1099         unsigned long oflags, *flags;
1100
1101         BUG_ON(ssif_info->waiting_msg);
1102         ssif_info->waiting_msg = msg;
1103
1104         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1105         start_next_msg(ssif_info, flags);
1106
1107         if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1108                 struct timespec64 t;
1109
1110                 ktime_get_real_ts64(&t);
1111                 dev_dbg(&ssif_info->client->dev,
1112                         "**Enqueue %02x %02x: %lld.%6.6ld\n",
1113                         msg->data[0], msg->data[1],
1114                         (long long)t.tv_sec, (long)t.tv_nsec / NSEC_PER_USEC);
1115         }
1116 }
1117
1118 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1119 {
1120         struct ssif_info *ssif_info = send_info;
1121
1122         data->addr_src = ssif_info->addr_source;
1123         data->dev = &ssif_info->client->dev;
1124         data->addr_info = ssif_info->addr_info;
1125         get_device(data->dev);
1126
1127         return 0;
1128 }
1129
1130 /*
1131  * Upper layer wants us to request events.
1132  */
1133 static void request_events(void *send_info)
1134 {
1135         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1136         unsigned long oflags, *flags;
1137
1138         if (!ssif_info->has_event_buffer)
1139                 return;
1140
1141         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1142         ssif_info->req_events = true;
1143         ipmi_ssif_unlock_cond(ssif_info, flags);
1144 }
1145
1146 /*
1147  * Upper layer is changing the flag saying whether we need to request
1148  * flags periodically or not.
1149  */
1150 static void ssif_set_need_watch(void *send_info, unsigned int watch_mask)
1151 {
1152         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1153         unsigned long oflags, *flags;
1154         long timeout = 0;
1155
1156         if (watch_mask & IPMI_WATCH_MASK_CHECK_MESSAGES)
1157                 timeout = SSIF_WATCH_MSG_TIMEOUT;
1158         else if (watch_mask)
1159                 timeout = SSIF_WATCH_WATCHDOG_TIMEOUT;
1160
1161         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1162         if (timeout != ssif_info->watch_timeout) {
1163                 ssif_info->watch_timeout = timeout;
1164                 if (ssif_info->watch_timeout)
1165                         mod_timer(&ssif_info->watch_timer,
1166                                   jiffies + ssif_info->watch_timeout);
1167         }
1168         ipmi_ssif_unlock_cond(ssif_info, flags);
1169 }
1170
1171 static int ssif_start_processing(void            *send_info,
1172                                  struct ipmi_smi *intf)
1173 {
1174         struct ssif_info *ssif_info = send_info;
1175
1176         ssif_info->intf = intf;
1177
1178         return 0;
1179 }
1180
1181 #define MAX_SSIF_BMCS 4
1182
1183 static unsigned short addr[MAX_SSIF_BMCS];
1184 static int num_addrs;
1185 module_param_array(addr, ushort, &num_addrs, 0);
1186 MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1187
1188 static char *adapter_name[MAX_SSIF_BMCS];
1189 static int num_adapter_names;
1190 module_param_array(adapter_name, charp, &num_adapter_names, 0);
1191 MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1192
1193 static int slave_addrs[MAX_SSIF_BMCS];
1194 static int num_slave_addrs;
1195 module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1196 MODULE_PARM_DESC(slave_addrs,
1197                  "The default IPMB slave address for the controller.");
1198
1199 static bool alerts_broken;
1200 module_param(alerts_broken, bool, 0);
1201 MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1202
1203 /*
1204  * Bit 0 enables message debugging, bit 1 enables state debugging, and
1205  * bit 2 enables timing debugging.  This is an array indexed by
1206  * interface number"
1207  */
1208 static int dbg[MAX_SSIF_BMCS];
1209 static int num_dbg;
1210 module_param_array(dbg, int, &num_dbg, 0);
1211 MODULE_PARM_DESC(dbg, "Turn on debugging.");
1212
1213 static bool ssif_dbg_probe;
1214 module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1215 MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1216
1217 static bool ssif_tryacpi = true;
1218 module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1219 MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1220
1221 static bool ssif_trydmi = true;
1222 module_param_named(trydmi, ssif_trydmi, bool, 0);
1223 MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1224
1225 static DEFINE_MUTEX(ssif_infos_mutex);
1226 static LIST_HEAD(ssif_infos);
1227
1228 #define IPMI_SSIF_ATTR(name) \
1229 static ssize_t ipmi_##name##_show(struct device *dev,                   \
1230                                   struct device_attribute *attr,        \
1231                                   char *buf)                            \
1232 {                                                                       \
1233         struct ssif_info *ssif_info = dev_get_drvdata(dev);             \
1234                                                                         \
1235         return snprintf(buf, 10, "%u\n", ssif_get_stat(ssif_info, name));\
1236 }                                                                       \
1237 static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL)
1238
1239 static ssize_t ipmi_type_show(struct device *dev,
1240                               struct device_attribute *attr,
1241                               char *buf)
1242 {
1243         return snprintf(buf, 10, "ssif\n");
1244 }
1245 static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL);
1246
1247 IPMI_SSIF_ATTR(sent_messages);
1248 IPMI_SSIF_ATTR(sent_messages_parts);
1249 IPMI_SSIF_ATTR(send_retries);
1250 IPMI_SSIF_ATTR(send_errors);
1251 IPMI_SSIF_ATTR(received_messages);
1252 IPMI_SSIF_ATTR(received_message_parts);
1253 IPMI_SSIF_ATTR(receive_retries);
1254 IPMI_SSIF_ATTR(receive_errors);
1255 IPMI_SSIF_ATTR(flag_fetches);
1256 IPMI_SSIF_ATTR(hosed);
1257 IPMI_SSIF_ATTR(events);
1258 IPMI_SSIF_ATTR(watchdog_pretimeouts);
1259 IPMI_SSIF_ATTR(alerts);
1260
1261 static struct attribute *ipmi_ssif_dev_attrs[] = {
1262         &dev_attr_type.attr,
1263         &dev_attr_sent_messages.attr,
1264         &dev_attr_sent_messages_parts.attr,
1265         &dev_attr_send_retries.attr,
1266         &dev_attr_send_errors.attr,
1267         &dev_attr_received_messages.attr,
1268         &dev_attr_received_message_parts.attr,
1269         &dev_attr_receive_retries.attr,
1270         &dev_attr_receive_errors.attr,
1271         &dev_attr_flag_fetches.attr,
1272         &dev_attr_hosed.attr,
1273         &dev_attr_events.attr,
1274         &dev_attr_watchdog_pretimeouts.attr,
1275         &dev_attr_alerts.attr,
1276         NULL
1277 };
1278
1279 static const struct attribute_group ipmi_ssif_dev_attr_group = {
1280         .attrs          = ipmi_ssif_dev_attrs,
1281 };
1282
1283 static void shutdown_ssif(void *send_info)
1284 {
1285         struct ssif_info *ssif_info = send_info;
1286
1287         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1288         dev_set_drvdata(&ssif_info->client->dev, NULL);
1289
1290         /* make sure the driver is not looking for flags any more. */
1291         while (ssif_info->ssif_state != SSIF_NORMAL)
1292                 schedule_timeout(1);
1293
1294         ssif_info->stopping = true;
1295         del_timer_sync(&ssif_info->watch_timer);
1296         del_timer_sync(&ssif_info->retry_timer);
1297         if (ssif_info->thread) {
1298                 complete(&ssif_info->wake_thread);
1299                 kthread_stop(ssif_info->thread);
1300         }
1301 }
1302
1303 static int ssif_remove(struct i2c_client *client)
1304 {
1305         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1306         struct ssif_addr_info *addr_info;
1307
1308         if (!ssif_info)
1309                 return 0;
1310
1311         /*
1312          * After this point, we won't deliver anything asychronously
1313          * to the message handler.  We can unregister ourself.
1314          */
1315         ipmi_unregister_smi(ssif_info->intf);
1316
1317         list_for_each_entry(addr_info, &ssif_infos, link) {
1318                 if (addr_info->client == client) {
1319                         addr_info->client = NULL;
1320                         break;
1321                 }
1322         }
1323
1324         kfree(ssif_info);
1325
1326         return 0;
1327 }
1328
1329 static int read_response(struct i2c_client *client, unsigned char *resp)
1330 {
1331         int ret = -ENODEV, retry_cnt = SSIF_RECV_RETRIES;
1332
1333         while (retry_cnt > 0) {
1334                 ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1335                                                 resp);
1336                 if (ret > 0)
1337                         break;
1338                 msleep(SSIF_MSG_MSEC);
1339                 retry_cnt--;
1340                 if (retry_cnt <= 0)
1341                         break;
1342         }
1343
1344         return ret;
1345 }
1346
1347 static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1348                   int *resp_len, unsigned char *resp)
1349 {
1350         int retry_cnt;
1351         int ret;
1352
1353         retry_cnt = SSIF_SEND_RETRIES;
1354  retry1:
1355         ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1356         if (ret) {
1357                 retry_cnt--;
1358                 if (retry_cnt > 0)
1359                         goto retry1;
1360                 return -ENODEV;
1361         }
1362
1363         ret = read_response(client, resp);
1364         if (ret > 0) {
1365                 /* Validate that the response is correct. */
1366                 if (ret < 3 ||
1367                     (resp[0] != (msg[0] | (1 << 2))) ||
1368                     (resp[1] != msg[1]))
1369                         ret = -EINVAL;
1370                 else if (ret > IPMI_MAX_MSG_LENGTH) {
1371                         ret = -E2BIG;
1372                 } else {
1373                         *resp_len = ret;
1374                         ret = 0;
1375                 }
1376         }
1377
1378         return ret;
1379 }
1380
1381 static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1382 {
1383         unsigned char *resp;
1384         unsigned char msg[3];
1385         int           rv;
1386         int           len;
1387
1388         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1389         if (!resp)
1390                 return -ENOMEM;
1391
1392         /* Do a Get Device ID command, since it is required. */
1393         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1394         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1395         rv = do_cmd(client, 2, msg, &len, resp);
1396         if (rv)
1397                 rv = -ENODEV;
1398         else
1399                 strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1400         kfree(resp);
1401         return rv;
1402 }
1403
1404 static int strcmp_nospace(char *s1, char *s2)
1405 {
1406         while (*s1 && *s2) {
1407                 while (isspace(*s1))
1408                         s1++;
1409                 while (isspace(*s2))
1410                         s2++;
1411                 if (*s1 > *s2)
1412                         return 1;
1413                 if (*s1 < *s2)
1414                         return -1;
1415                 s1++;
1416                 s2++;
1417         }
1418         return 0;
1419 }
1420
1421 static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1422                                              char *adapter_name,
1423                                              bool match_null_name)
1424 {
1425         struct ssif_addr_info *info, *found = NULL;
1426
1427 restart:
1428         list_for_each_entry(info, &ssif_infos, link) {
1429                 if (info->binfo.addr == addr) {
1430                         if (info->addr_src == SI_SMBIOS)
1431                                 info->adapter_name = kstrdup(adapter_name,
1432                                                              GFP_KERNEL);
1433
1434                         if (info->adapter_name || adapter_name) {
1435                                 if (!info->adapter_name != !adapter_name) {
1436                                         /* One is NULL and one is not */
1437                                         continue;
1438                                 }
1439                                 if (adapter_name &&
1440                                     strcmp_nospace(info->adapter_name,
1441                                                    adapter_name))
1442                                         /* Names do not match */
1443                                         continue;
1444                         }
1445                         found = info;
1446                         break;
1447                 }
1448         }
1449
1450         if (!found && match_null_name) {
1451                 /* Try to get an exact match first, then try with a NULL name */
1452                 adapter_name = NULL;
1453                 match_null_name = false;
1454                 goto restart;
1455         }
1456
1457         return found;
1458 }
1459
1460 static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1461 {
1462 #ifdef CONFIG_ACPI
1463         acpi_handle acpi_handle;
1464
1465         acpi_handle = ACPI_HANDLE(dev);
1466         if (acpi_handle) {
1467                 ssif_info->addr_source = SI_ACPI;
1468                 ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1469                 return true;
1470         }
1471 #endif
1472         return false;
1473 }
1474
1475 static int find_slave_address(struct i2c_client *client, int slave_addr)
1476 {
1477 #ifdef CONFIG_IPMI_DMI_DECODE
1478         if (!slave_addr)
1479                 slave_addr = ipmi_dmi_get_slave_addr(
1480                         SI_TYPE_INVALID,
1481                         i2c_adapter_id(client->adapter),
1482                         client->addr);
1483 #endif
1484
1485         return slave_addr;
1486 }
1487
1488 static int start_multipart_test(struct i2c_client *client,
1489                                 unsigned char *msg, bool do_middle)
1490 {
1491         int retry_cnt = SSIF_SEND_RETRIES, ret;
1492
1493 retry_write:
1494         ret = i2c_smbus_write_block_data(client,
1495                                          SSIF_IPMI_MULTI_PART_REQUEST_START,
1496                                          32, msg);
1497         if (ret) {
1498                 retry_cnt--;
1499                 if (retry_cnt > 0)
1500                         goto retry_write;
1501                 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");
1502                 return ret;
1503         }
1504
1505         if (!do_middle)
1506                 return 0;
1507
1508         ret = i2c_smbus_write_block_data(client,
1509                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1510                                          32, msg + 32);
1511         if (ret) {
1512                 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");
1513                 return ret;
1514         }
1515
1516         return 0;
1517 }
1518
1519 static void test_multipart_messages(struct i2c_client *client,
1520                                     struct ssif_info *ssif_info,
1521                                     unsigned char *resp)
1522 {
1523         unsigned char msg[65];
1524         int ret;
1525         bool do_middle;
1526
1527         if (ssif_info->max_xmit_msg_size <= 32)
1528                 return;
1529
1530         do_middle = ssif_info->max_xmit_msg_size > 63;
1531
1532         memset(msg, 0, sizeof(msg));
1533         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1534         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1535
1536         /*
1537          * The specification is all messed up dealing with sending
1538          * multi-part messages.  Per what the specification says, it
1539          * is impossible to send a message that is a multiple of 32
1540          * bytes, except for 32 itself.  It talks about a "start"
1541          * transaction (cmd=6) that must be 32 bytes, "middle"
1542          * transaction (cmd=7) that must be 32 bytes, and an "end"
1543          * transaction.  The "end" transaction is shown as cmd=7 in
1544          * the text, but if that's the case there is no way to
1545          * differentiate between a middle and end part except the
1546          * length being less than 32.  But there is a table at the far
1547          * end of the section (that I had never noticed until someone
1548          * pointed it out to me) that mentions it as cmd=8.
1549          *
1550          * After some thought, I think the example is wrong and the
1551          * end transaction should be cmd=8.  But some systems don't
1552          * implement cmd=8, they use a zero-length end transaction,
1553          * even though that violates the SMBus specification.
1554          *
1555          * So, to work around this, this code tests if cmd=8 works.
1556          * If it does, then we use that.  If not, it tests zero-
1557          * byte end transactions.  If that works, good.  If not,
1558          * we only allow 63-byte transactions max.
1559          */
1560
1561         ret = start_multipart_test(client, msg, do_middle);
1562         if (ret)
1563                 goto out_no_multi_part;
1564
1565         ret = i2c_smbus_write_block_data(client,
1566                                          SSIF_IPMI_MULTI_PART_REQUEST_END,
1567                                          1, msg + 64);
1568
1569         if (!ret)
1570                 ret = read_response(client, resp);
1571
1572         if (ret > 0) {
1573                 /* End transactions work, we are good. */
1574                 ssif_info->cmd8_works = true;
1575                 return;
1576         }
1577
1578         ret = start_multipart_test(client, msg, do_middle);
1579         if (ret) {
1580                 dev_err(&client->dev, "Second multipart test failed.\n");
1581                 goto out_no_multi_part;
1582         }
1583
1584         ret = i2c_smbus_write_block_data(client,
1585                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1586                                          0, msg + 64);
1587         if (!ret)
1588                 ret = read_response(client, resp);
1589         if (ret > 0)
1590                 /* Zero-size end parts work, use those. */
1591                 return;
1592
1593         /* Limit to 63 bytes and use a short middle command to mark the end. */
1594         if (ssif_info->max_xmit_msg_size > 63)
1595                 ssif_info->max_xmit_msg_size = 63;
1596         return;
1597
1598 out_no_multi_part:
1599         ssif_info->max_xmit_msg_size = 32;
1600         return;
1601 }
1602
1603 /*
1604  * Global enables we care about.
1605  */
1606 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1607                              IPMI_BMC_EVT_MSG_INTR)
1608
1609 static void ssif_remove_dup(struct i2c_client *client)
1610 {
1611         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1612
1613         ipmi_unregister_smi(ssif_info->intf);
1614         kfree(ssif_info);
1615 }
1616
1617 static int ssif_add_infos(struct i2c_client *client)
1618 {
1619         struct ssif_addr_info *info;
1620
1621         info = kzalloc(sizeof(*info), GFP_KERNEL);
1622         if (!info)
1623                 return -ENOMEM;
1624         info->addr_src = SI_ACPI;
1625         info->client = client;
1626         info->adapter_name = kstrdup(client->adapter->name, GFP_KERNEL);
1627         info->binfo.addr = client->addr;
1628         list_add_tail(&info->link, &ssif_infos);
1629         return 0;
1630 }
1631
1632 /*
1633  * Prefer ACPI over SMBIOS, if both are available.
1634  * So if we get an ACPI interface and have already registered a SMBIOS
1635  * interface at the same address, remove the SMBIOS and add the ACPI one.
1636  */
1637 static int ssif_check_and_remove(struct i2c_client *client,
1638                               struct ssif_info *ssif_info)
1639 {
1640         struct ssif_addr_info *info;
1641
1642         list_for_each_entry(info, &ssif_infos, link) {
1643                 if (!info->client)
1644                         return 0;
1645                 if (!strcmp(info->adapter_name, client->adapter->name) &&
1646                     info->binfo.addr == client->addr) {
1647                         if (info->addr_src == SI_ACPI)
1648                                 return -EEXIST;
1649
1650                         if (ssif_info->addr_source == SI_ACPI &&
1651                             info->addr_src == SI_SMBIOS) {
1652                                 dev_info(&client->dev,
1653                                          "Removing %s-specified SSIF interface in favor of ACPI\n",
1654                                          ipmi_addr_src_to_str(info->addr_src));
1655                                 ssif_remove_dup(info->client);
1656                                 return 0;
1657                         }
1658                 }
1659         }
1660         return 0;
1661 }
1662
1663 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1664 {
1665         unsigned char     msg[3];
1666         unsigned char     *resp;
1667         struct ssif_info   *ssif_info;
1668         int               rv = 0;
1669         int               len;
1670         int               i;
1671         u8                slave_addr = 0;
1672         struct ssif_addr_info *addr_info = NULL;
1673
1674         mutex_lock(&ssif_infos_mutex);
1675         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1676         if (!resp) {
1677                 mutex_unlock(&ssif_infos_mutex);
1678                 return -ENOMEM;
1679         }
1680
1681         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1682         if (!ssif_info) {
1683                 kfree(resp);
1684                 mutex_unlock(&ssif_infos_mutex);
1685                 return -ENOMEM;
1686         }
1687
1688         if (!check_acpi(ssif_info, &client->dev)) {
1689                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1690                                            true);
1691                 if (!addr_info) {
1692                         /* Must have come in through sysfs. */
1693                         ssif_info->addr_source = SI_HOTMOD;
1694                 } else {
1695                         ssif_info->addr_source = addr_info->addr_src;
1696                         ssif_info->ssif_debug = addr_info->debug;
1697                         ssif_info->addr_info = addr_info->addr_info;
1698                         addr_info->client = client;
1699                         slave_addr = addr_info->slave_addr;
1700                 }
1701         }
1702
1703         rv = ssif_check_and_remove(client, ssif_info);
1704         /* If rv is 0 and addr source is not SI_ACPI, continue probing */
1705         if (!rv && ssif_info->addr_source == SI_ACPI) {
1706                 rv = ssif_add_infos(client);
1707                 if (rv) {
1708                         dev_err(&client->dev, "Out of memory!, exiting ..\n");
1709                         goto out;
1710                 }
1711         } else if (rv) {
1712                 dev_err(&client->dev, "Not probing, Interface already present\n");
1713                 goto out;
1714         }
1715
1716         slave_addr = find_slave_address(client, slave_addr);
1717
1718         dev_info(&client->dev,
1719                  "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1720                 ipmi_addr_src_to_str(ssif_info->addr_source),
1721                 client->addr, client->adapter->name, slave_addr);
1722
1723         ssif_info->client = client;
1724         i2c_set_clientdata(client, ssif_info);
1725
1726         /* Now check for system interface capabilities */
1727         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1728         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1729         msg[2] = 0; /* SSIF */
1730         rv = do_cmd(client, 3, msg, &len, resp);
1731         if (!rv && (len >= 3) && (resp[2] == 0)) {
1732                 if (len < 7) {
1733                         if (ssif_dbg_probe)
1734                                 dev_dbg(&ssif_info->client->dev,
1735                                         "SSIF info too short: %d\n", len);
1736                         goto no_support;
1737                 }
1738
1739                 /* Got a good SSIF response, handle it. */
1740                 ssif_info->max_xmit_msg_size = resp[5];
1741                 ssif_info->max_recv_msg_size = resp[6];
1742                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1743                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1744
1745                 /* Sanitize the data */
1746                 switch (ssif_info->multi_support) {
1747                 case SSIF_NO_MULTI:
1748                         if (ssif_info->max_xmit_msg_size > 32)
1749                                 ssif_info->max_xmit_msg_size = 32;
1750                         if (ssif_info->max_recv_msg_size > 32)
1751                                 ssif_info->max_recv_msg_size = 32;
1752                         break;
1753
1754                 case SSIF_MULTI_2_PART:
1755                         if (ssif_info->max_xmit_msg_size > 63)
1756                                 ssif_info->max_xmit_msg_size = 63;
1757                         if (ssif_info->max_recv_msg_size > 62)
1758                                 ssif_info->max_recv_msg_size = 62;
1759                         break;
1760
1761                 case SSIF_MULTI_n_PART:
1762                         /* We take whatever size given, but do some testing. */
1763                         break;
1764
1765                 default:
1766                         /* Data is not sane, just give up. */
1767                         goto no_support;
1768                 }
1769         } else {
1770  no_support:
1771                 /* Assume no multi-part or PEC support */
1772                 dev_info(&ssif_info->client->dev,
1773                          "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1774                         rv, len, resp[2]);
1775
1776                 ssif_info->max_xmit_msg_size = 32;
1777                 ssif_info->max_recv_msg_size = 32;
1778                 ssif_info->multi_support = SSIF_NO_MULTI;
1779                 ssif_info->supports_pec = 0;
1780         }
1781
1782         test_multipart_messages(client, ssif_info, resp);
1783
1784         /* Make sure the NMI timeout is cleared. */
1785         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1786         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1787         msg[2] = WDT_PRE_TIMEOUT_INT;
1788         rv = do_cmd(client, 3, msg, &len, resp);
1789         if (rv || (len < 3) || (resp[2] != 0))
1790                 dev_warn(&ssif_info->client->dev,
1791                          "Unable to clear message flags: %d %d %2.2x\n",
1792                          rv, len, resp[2]);
1793
1794         /* Attempt to enable the event buffer. */
1795         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1796         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1797         rv = do_cmd(client, 2, msg, &len, resp);
1798         if (rv || (len < 4) || (resp[2] != 0)) {
1799                 dev_warn(&ssif_info->client->dev,
1800                          "Error getting global enables: %d %d %2.2x\n",
1801                          rv, len, resp[2]);
1802                 rv = 0; /* Not fatal */
1803                 goto found;
1804         }
1805
1806         ssif_info->global_enables = resp[3];
1807
1808         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1809                 ssif_info->has_event_buffer = true;
1810                 /* buffer is already enabled, nothing to do. */
1811                 goto found;
1812         }
1813
1814         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1815         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1816         msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1817         rv = do_cmd(client, 3, msg, &len, resp);
1818         if (rv || (len < 2)) {
1819                 dev_warn(&ssif_info->client->dev,
1820                          "Error setting global enables: %d %d %2.2x\n",
1821                          rv, len, resp[2]);
1822                 rv = 0; /* Not fatal */
1823                 goto found;
1824         }
1825
1826         if (resp[2] == 0) {
1827                 /* A successful return means the event buffer is supported. */
1828                 ssif_info->has_event_buffer = true;
1829                 ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1830         }
1831
1832         /* Some systems don't behave well if you enable alerts. */
1833         if (alerts_broken)
1834                 goto found;
1835
1836         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1837         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1838         msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1839         rv = do_cmd(client, 3, msg, &len, resp);
1840         if (rv || (len < 2)) {
1841                 dev_warn(&ssif_info->client->dev,
1842                          "Error setting global enables: %d %d %2.2x\n",
1843                          rv, len, resp[2]);
1844                 rv = 0; /* Not fatal */
1845                 goto found;
1846         }
1847
1848         if (resp[2] == 0) {
1849                 /* A successful return means the alert is supported. */
1850                 ssif_info->supports_alert = true;
1851                 ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1852         }
1853
1854  found:
1855         if (ssif_dbg_probe) {
1856                 dev_dbg(&ssif_info->client->dev,
1857                        "%s: i2c_probe found device at i2c address %x\n",
1858                        __func__, client->addr);
1859         }
1860
1861         spin_lock_init(&ssif_info->lock);
1862         ssif_info->ssif_state = SSIF_NORMAL;
1863         timer_setup(&ssif_info->retry_timer, retry_timeout, 0);
1864         timer_setup(&ssif_info->watch_timer, watch_timeout, 0);
1865
1866         for (i = 0; i < SSIF_NUM_STATS; i++)
1867                 atomic_set(&ssif_info->stats[i], 0);
1868
1869         if (ssif_info->supports_pec)
1870                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1871
1872         ssif_info->handlers.owner = THIS_MODULE;
1873         ssif_info->handlers.start_processing = ssif_start_processing;
1874         ssif_info->handlers.shutdown = shutdown_ssif;
1875         ssif_info->handlers.get_smi_info = get_smi_info;
1876         ssif_info->handlers.sender = sender;
1877         ssif_info->handlers.request_events = request_events;
1878         ssif_info->handlers.set_need_watch = ssif_set_need_watch;
1879
1880         {
1881                 unsigned int thread_num;
1882
1883                 thread_num = ((i2c_adapter_id(ssif_info->client->adapter)
1884                                << 8) |
1885                               ssif_info->client->addr);
1886                 init_completion(&ssif_info->wake_thread);
1887                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1888                                                "kssif%4.4x", thread_num);
1889                 if (IS_ERR(ssif_info->thread)) {
1890                         rv = PTR_ERR(ssif_info->thread);
1891                         dev_notice(&ssif_info->client->dev,
1892                                    "Could not start kernel thread: error %d\n",
1893                                    rv);
1894                         goto out;
1895                 }
1896         }
1897
1898         dev_set_drvdata(&ssif_info->client->dev, ssif_info);
1899         rv = device_add_group(&ssif_info->client->dev,
1900                               &ipmi_ssif_dev_attr_group);
1901         if (rv) {
1902                 dev_err(&ssif_info->client->dev,
1903                         "Unable to add device attributes: error %d\n",
1904                         rv);
1905                 goto out;
1906         }
1907
1908         rv = ipmi_register_smi(&ssif_info->handlers,
1909                                ssif_info,
1910                                &ssif_info->client->dev,
1911                                slave_addr);
1912         if (rv) {
1913                 dev_err(&ssif_info->client->dev,
1914                         "Unable to register device: error %d\n", rv);
1915                 goto out_remove_attr;
1916         }
1917
1918  out:
1919         if (rv) {
1920                 if (addr_info)
1921                         addr_info->client = NULL;
1922
1923                 dev_err(&ssif_info->client->dev,
1924                         "Unable to start IPMI SSIF: %d\n", rv);
1925                 kfree(ssif_info);
1926         }
1927         kfree(resp);
1928         mutex_unlock(&ssif_infos_mutex);
1929         return rv;
1930
1931 out_remove_attr:
1932         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1933         dev_set_drvdata(&ssif_info->client->dev, NULL);
1934         goto out;
1935 }
1936
1937 static int ssif_adapter_handler(struct device *adev, void *opaque)
1938 {
1939         struct ssif_addr_info *addr_info = opaque;
1940
1941         if (adev->type != &i2c_adapter_type)
1942                 return 0;
1943
1944         addr_info->added_client = i2c_new_device(to_i2c_adapter(adev),
1945                                                  &addr_info->binfo);
1946
1947         if (!addr_info->adapter_name)
1948                 return 1; /* Only try the first I2C adapter by default. */
1949         return 0;
1950 }
1951
1952 static int new_ssif_client(int addr, char *adapter_name,
1953                            int debug, int slave_addr,
1954                            enum ipmi_addr_src addr_src,
1955                            struct device *dev)
1956 {
1957         struct ssif_addr_info *addr_info;
1958         int rv = 0;
1959
1960         mutex_lock(&ssif_infos_mutex);
1961         if (ssif_info_find(addr, adapter_name, false)) {
1962                 rv = -EEXIST;
1963                 goto out_unlock;
1964         }
1965
1966         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1967         if (!addr_info) {
1968                 rv = -ENOMEM;
1969                 goto out_unlock;
1970         }
1971
1972         if (adapter_name) {
1973                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1974                 if (!addr_info->adapter_name) {
1975                         kfree(addr_info);
1976                         rv = -ENOMEM;
1977                         goto out_unlock;
1978                 }
1979         }
1980
1981         strncpy(addr_info->binfo.type, DEVICE_NAME,
1982                 sizeof(addr_info->binfo.type));
1983         addr_info->binfo.addr = addr;
1984         addr_info->binfo.platform_data = addr_info;
1985         addr_info->debug = debug;
1986         addr_info->slave_addr = slave_addr;
1987         addr_info->addr_src = addr_src;
1988         addr_info->dev = dev;
1989
1990         if (dev)
1991                 dev_set_drvdata(dev, addr_info);
1992
1993         list_add_tail(&addr_info->link, &ssif_infos);
1994
1995         if (initialized)
1996                 i2c_for_each_dev(addr_info, ssif_adapter_handler);
1997         /* Otherwise address list will get it */
1998
1999 out_unlock:
2000         mutex_unlock(&ssif_infos_mutex);
2001         return rv;
2002 }
2003
2004 static void free_ssif_clients(void)
2005 {
2006         struct ssif_addr_info *info, *tmp;
2007
2008         mutex_lock(&ssif_infos_mutex);
2009         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
2010                 list_del(&info->link);
2011                 kfree(info->adapter_name);
2012                 kfree(info);
2013         }
2014         mutex_unlock(&ssif_infos_mutex);
2015 }
2016
2017 static unsigned short *ssif_address_list(void)
2018 {
2019         struct ssif_addr_info *info;
2020         unsigned int count = 0, i = 0;
2021         unsigned short *address_list;
2022
2023         list_for_each_entry(info, &ssif_infos, link)
2024                 count++;
2025
2026         address_list = kcalloc(count + 1, sizeof(*address_list),
2027                                GFP_KERNEL);
2028         if (!address_list)
2029                 return NULL;
2030
2031         list_for_each_entry(info, &ssif_infos, link) {
2032                 unsigned short addr = info->binfo.addr;
2033                 int j;
2034
2035                 for (j = 0; j < i; j++) {
2036                         if (address_list[j] == addr)
2037                                 /* Found a dup. */
2038                                 break;
2039                 }
2040                 if (j == i) /* Didn't find it in the list. */
2041                         address_list[i++] = addr;
2042         }
2043         address_list[i] = I2C_CLIENT_END;
2044
2045         return address_list;
2046 }
2047
2048 #ifdef CONFIG_ACPI
2049 static const struct acpi_device_id ssif_acpi_match[] = {
2050         { "IPI0001", 0 },
2051         { },
2052 };
2053 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
2054 #endif
2055
2056 #ifdef CONFIG_DMI
2057 static int dmi_ipmi_probe(struct platform_device *pdev)
2058 {
2059         u8 slave_addr = 0;
2060         u16 i2c_addr;
2061         int rv;
2062
2063         if (!ssif_trydmi)
2064                 return -ENODEV;
2065
2066         rv = device_property_read_u16(&pdev->dev, "i2c-addr", &i2c_addr);
2067         if (rv) {
2068                 dev_warn(&pdev->dev, "No i2c-addr property\n");
2069                 return -ENODEV;
2070         }
2071
2072         rv = device_property_read_u8(&pdev->dev, "slave-addr", &slave_addr);
2073         if (rv)
2074                 slave_addr = 0x20;
2075
2076         return new_ssif_client(i2c_addr, NULL, 0,
2077                                slave_addr, SI_SMBIOS, &pdev->dev);
2078 }
2079 #else
2080 static int dmi_ipmi_probe(struct platform_device *pdev)
2081 {
2082         return -ENODEV;
2083 }
2084 #endif
2085
2086 static const struct i2c_device_id ssif_id[] = {
2087         { DEVICE_NAME, 0 },
2088         { }
2089 };
2090 MODULE_DEVICE_TABLE(i2c, ssif_id);
2091
2092 static struct i2c_driver ssif_i2c_driver = {
2093         .class          = I2C_CLASS_HWMON,
2094         .driver         = {
2095                 .name                   = DEVICE_NAME
2096         },
2097         .probe          = ssif_probe,
2098         .remove         = ssif_remove,
2099         .alert          = ssif_alert,
2100         .id_table       = ssif_id,
2101         .detect         = ssif_detect
2102 };
2103
2104 static int ssif_platform_probe(struct platform_device *dev)
2105 {
2106         return dmi_ipmi_probe(dev);
2107 }
2108
2109 static int ssif_platform_remove(struct platform_device *dev)
2110 {
2111         struct ssif_addr_info *addr_info = dev_get_drvdata(&dev->dev);
2112
2113         if (!addr_info)
2114                 return 0;
2115
2116         mutex_lock(&ssif_infos_mutex);
2117         i2c_unregister_device(addr_info->added_client);
2118
2119         list_del(&addr_info->link);
2120         kfree(addr_info);
2121         mutex_unlock(&ssif_infos_mutex);
2122         return 0;
2123 }
2124
2125 static const struct platform_device_id ssif_plat_ids[] = {
2126     { "dmi-ipmi-ssif", 0 },
2127     { }
2128 };
2129
2130 static struct platform_driver ipmi_driver = {
2131         .driver = {
2132                 .name = DEVICE_NAME,
2133         },
2134         .probe          = ssif_platform_probe,
2135         .remove         = ssif_platform_remove,
2136         .id_table       = ssif_plat_ids
2137 };
2138
2139 static int init_ipmi_ssif(void)
2140 {
2141         int i;
2142         int rv;
2143
2144         if (initialized)
2145                 return 0;
2146
2147         pr_info("IPMI SSIF Interface driver\n");
2148
2149         /* build list for i2c from addr list */
2150         for (i = 0; i < num_addrs; i++) {
2151                 rv = new_ssif_client(addr[i], adapter_name[i],
2152                                      dbg[i], slave_addrs[i],
2153                                      SI_HARDCODED, NULL);
2154                 if (rv)
2155                         pr_err("Couldn't add hardcoded device at addr 0x%x\n",
2156                                addr[i]);
2157         }
2158
2159         if (ssif_tryacpi)
2160                 ssif_i2c_driver.driver.acpi_match_table =
2161                         ACPI_PTR(ssif_acpi_match);
2162
2163         if (ssif_trydmi) {
2164                 rv = platform_driver_register(&ipmi_driver);
2165                 if (rv)
2166                         pr_err("Unable to register driver: %d\n", rv);
2167                 else
2168                         platform_registered = true;
2169         }
2170
2171         ssif_i2c_driver.address_list = ssif_address_list();
2172
2173         rv = i2c_add_driver(&ssif_i2c_driver);
2174         if (!rv)
2175                 initialized = true;
2176
2177         return rv;
2178 }
2179 module_init(init_ipmi_ssif);
2180
2181 static void cleanup_ipmi_ssif(void)
2182 {
2183         if (!initialized)
2184                 return;
2185
2186         initialized = false;
2187
2188         i2c_del_driver(&ssif_i2c_driver);
2189
2190         kfree(ssif_i2c_driver.address_list);
2191
2192         if (ssif_trydmi && platform_registered)
2193                 platform_driver_unregister(&ipmi_driver);
2194
2195         free_ssif_clients();
2196 }
2197 module_exit(cleanup_ipmi_ssif);
2198
2199 MODULE_ALIAS("platform:dmi-ipmi-ssif");
2200 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2201 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2202 MODULE_LICENSE("GPL");