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_si_sm.h"
  56 #include "ipmi_dmi.h"
  57
  58 #define DEVICE_NAME "ipmi_ssif"
  59
  60 #define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD      0x57
  61
  62 #define SSIF_IPMI_REQUEST                       2
  63 #define SSIF_IPMI_MULTI_PART_REQUEST_START      6
  64 #define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE     7
  65 #define SSIF_IPMI_MULTI_PART_REQUEST_END        8
  66 #define SSIF_IPMI_RESPONSE                      3
  67 #define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE    9
  68
  69 /* ssif_debug is a bit-field
  70  *      SSIF_DEBUG_MSG -        commands and their responses
  71  *      SSIF_DEBUG_STATES -     message states
  72  *      SSIF_DEBUG_TIMING -      Measure times between events in the driver
  73  */
  74 #define SSIF_DEBUG_TIMING       4
  75 #define SSIF_DEBUG_STATE        2
  76 #define SSIF_DEBUG_MSG          1
  77 #define SSIF_NODEBUG            0
  78 #define SSIF_DEFAULT_DEBUG      (SSIF_NODEBUG)
  79
  80 /*
  81  * Timer values
  82  */
  83 #define SSIF_MSG_USEC           20000   /* 20ms between message tries. */
  84 #define SSIF_MSG_PART_USEC      5000    /* 5ms for a message part */
  85
  86 /* How many times to we retry sending/receiving the message. */
  87 #define SSIF_SEND_RETRIES       5
  88 #define SSIF_RECV_RETRIES       250
  89
  90 #define SSIF_MSG_MSEC           (SSIF_MSG_USEC / 1000)
  91 #define SSIF_MSG_JIFFIES        ((SSIF_MSG_USEC * 1000) / TICK_NSEC)
  92 #define SSIF_MSG_PART_JIFFIES   ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
  93
  94 /*
  95  * Timeout for the watch, only used for get flag timer.
  96  */
  97 #define SSIF_WATCH_MSG_TIMEOUT          msecs_to_jiffies(10)
  98 #define SSIF_WATCH_WATCHDOG_TIMEOUT     msecs_to_jiffies(250)
  99
 100 enum ssif_intf_state {
 101         SSIF_NORMAL,
 102         SSIF_GETTING_FLAGS,
 103         SSIF_GETTING_EVENTS,
 104         SSIF_CLEARING_FLAGS,
 105         SSIF_GETTING_MESSAGES,
 106         /* FIXME - add watchdog stuff. */
 107 };
 108
 109 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
 110                           && (ssif)->curr_msg == NULL)
 111
 112 /*
 113  * Indexes into stats[] in ssif_info below.
 114  */
 115 enum ssif_stat_indexes {
 116         /* Number of total messages sent. */
 117         SSIF_STAT_sent_messages = 0,
 118
 119         /*
 120          * Number of message parts sent.  Messages may be broken into
 121          * parts if they are long.
 122          */
 123         SSIF_STAT_sent_messages_parts,
 124
 125         /*
 126          * Number of time a message was retried.
 127          */
 128         SSIF_STAT_send_retries,
 129
 130         /*
 131          * Number of times the send of a message failed.
 132          */
 133         SSIF_STAT_send_errors,
 134
 135         /*
 136          * Number of message responses received.
 137          */
 138         SSIF_STAT_received_messages,
 139
 140         /*
 141          * Number of message fragments received.
 142          */
 143         SSIF_STAT_received_message_parts,
 144
 145         /*
 146          * Number of times the receive of a message was retried.
 147          */
 148         SSIF_STAT_receive_retries,
 149
 150         /*
 151          * Number of errors receiving messages.
 152          */
 153         SSIF_STAT_receive_errors,
 154
 155         /*
 156          * Number of times a flag fetch was requested.
 157          */
 158         SSIF_STAT_flag_fetches,
 159
 160         /*
 161          * Number of times the hardware didn't follow the state machine.
 162          */
 163         SSIF_STAT_hosed,
 164
 165         /*
 166          * Number of received events.
 167          */
 168         SSIF_STAT_events,
 169
 170         /* Number of asyncronous messages received. */
 171         SSIF_STAT_incoming_messages,
 172
 173         /* Number of watchdog pretimeouts. */
 174         SSIF_STAT_watchdog_pretimeouts,
 175
 176         /* Number of alers received. */
 177         SSIF_STAT_alerts,
 178
 179         /* Always add statistics before this value, it must be last. */
 180         SSIF_NUM_STATS
 181 };
 182
 183 struct ssif_addr_info {
 184         struct i2c_board_info binfo;
 185         char *adapter_name;
 186         int debug;
 187         int slave_addr;
 188         enum ipmi_addr_src addr_src;
 189         union ipmi_smi_info_union addr_info;
 190         struct device *dev;
 191         struct i2c_client *client;
 192
 193         struct i2c_client *added_client;
 194
 195         struct mutex clients_mutex;
 196         struct list_head clients;
 197
 198         struct list_head link;
 199 };
 200
 201 struct ssif_info;
 202
 203 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
 204                              unsigned char *data, unsigned int len);
 205
 206 struct ssif_info {
 207         struct ipmi_smi     *intf;
 208         spinlock_t          lock;
 209         struct ipmi_smi_msg *waiting_msg;
 210         struct ipmi_smi_msg *curr_msg;
 211         enum ssif_intf_state ssif_state;
 212         unsigned long       ssif_debug;
 213
 214         struct ipmi_smi_handlers handlers;
 215
 216         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
 217         union ipmi_smi_info_union addr_info;
 218
 219         /*
 220          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 221          * is set to hold the flags until we are done handling everything
 222          * from the flags.
 223          */
 224 #define RECEIVE_MSG_AVAIL       0x01
 225 #define EVENT_MSG_BUFFER_FULL   0x02
 226 #define WDT_PRE_TIMEOUT_INT     0x08
 227         unsigned char       msg_flags;
 228
 229         u8                  global_enables;
 230         bool                has_event_buffer;
 231         bool                supports_alert;
 232
 233         /*
 234          * Used to tell what we should do with alerts.  If we are
 235          * waiting on a response, read the data immediately.
 236          */
 237         bool                got_alert;
 238         bool                waiting_alert;
 239
 240         /*
 241          * If set to true, this will request events the next time the
 242          * state machine is idle.
 243          */
 244         bool                req_events;
 245
 246         /*
 247          * If set to true, this will request flags the next time the
 248          * state machine is idle.
 249          */
 250         bool                req_flags;
 251
 252         /*
 253          * Used to perform timer operations when run-to-completion
 254          * mode is on.  This is a countdown timer.
 255          */
 256         int                 rtc_us_timer;
 257
 258         /* Used for sending/receiving data.  +1 for the length. */
 259         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
 260         unsigned int  data_len;
 261
 262         /* Temp receive buffer, gets copied into data. */
 263         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
 264
 265         struct i2c_client *client;
 266         ssif_i2c_done done_handler;
 267
 268         /* Thread interface handling */
 269         struct task_struct *thread;
 270         struct completion wake_thread;
 271         bool stopping;
 272         int i2c_read_write;
 273         int i2c_command;
 274         unsigned char *i2c_data;
 275         unsigned int i2c_size;
 276
 277         struct timer_list retry_timer;
 278         int retries_left;
 279
 280         long watch_timeout;             /* Timeout for flags check, 0 if off. */
 281         struct timer_list watch_timer;  /* Flag fetch timer. */
 282
 283         /* Info from SSIF cmd */
 284         unsigned char max_xmit_msg_size;
 285         unsigned char max_recv_msg_size;
 286         bool cmd8_works; /* See test_multipart_messages() for details. */
 287         unsigned int  multi_support;
 288         int           supports_pec;
 289
 290 #define SSIF_NO_MULTI           0
 291 #define SSIF_MULTI_2_PART       1
 292 #define SSIF_MULTI_n_PART       2
 293         unsigned char *multi_data;
 294         unsigned int  multi_len;
 295         unsigned int  multi_pos;
 296
 297         atomic_t stats[SSIF_NUM_STATS];
 298 };
 299
 300 #define ssif_inc_stat(ssif, stat) \
 301         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
 302 #define ssif_get_stat(ssif, stat) \
 303         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
 304
 305 static bool initialized;
 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 != 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                         result = -EIO;
 737                 } else {
 738                         ssif_inc_stat(ssif_info, received_message_parts);
 739
 740                         ssif_info->multi_pos++;
 741
 742                         rv = ssif_i2c_send(ssif_info, msg_done_handler,
 743                                            I2C_SMBUS_READ,
 744                                            SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 745                                            ssif_info->recv,
 746                                            I2C_SMBUS_BLOCK_DATA);
 747                         if (rv < 0) {
 748                                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 749                                         dev_dbg(&ssif_info->client->dev,
 750                                                 "Error from ssif_i2c_send\n");
 751
 752                                 result = -EIO;
 753                         } else
 754                                 return;
 755                 }
 756         }
 757
 758  continue_op:
 759         if (result < 0) {
 760                 ssif_inc_stat(ssif_info, receive_errors);
 761         } else {
 762                 ssif_inc_stat(ssif_info, received_messages);
 763                 ssif_inc_stat(ssif_info, received_message_parts);
 764         }
 765
 766         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 767                 dev_dbg(&ssif_info->client->dev,
 768                         "DONE 1: state = %d, result=%d\n",
 769                         ssif_info->ssif_state, result);
 770
 771         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 772         msg = ssif_info->curr_msg;
 773         if (msg) {
 774                 msg->rsp_size = len;
 775                 if (msg->rsp_size > IPMI_MAX_MSG_LENGTH)
 776                         msg->rsp_size = IPMI_MAX_MSG_LENGTH;
 777                 memcpy(msg->rsp, data, msg->rsp_size);
 778                 ssif_info->curr_msg = NULL;
 779         }
 780
 781         switch (ssif_info->ssif_state) {
 782         case SSIF_NORMAL:
 783                 ipmi_ssif_unlock_cond(ssif_info, flags);
 784                 if (!msg)
 785                         break;
 786
 787                 if (result < 0)
 788                         return_hosed_msg(ssif_info, msg);
 789                 else
 790                         deliver_recv_msg(ssif_info, msg);
 791                 break;
 792
 793         case SSIF_GETTING_FLAGS:
 794                 /* We got the flags from the SSIF, now handle them. */
 795                 if ((result < 0) || (len < 4) || (data[2] != 0)) {
 796                         /*
 797                          * Error fetching flags, or invalid length,
 798                          * just give up for now.
 799                          */
 800                         ssif_info->ssif_state = SSIF_NORMAL;
 801                         ipmi_ssif_unlock_cond(ssif_info, flags);
 802                         dev_warn(&ssif_info->client->dev,
 803                                  "Error getting flags: %d %d, %x\n",
 804                                  result, len, (len >= 3) ? data[2] : 0);
 805                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 806                            || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
 807                         /*
 808                          * Don't abort here, maybe it was a queued
 809                          * response to a previous command.
 810                          */
 811                         ipmi_ssif_unlock_cond(ssif_info, flags);
 812                         dev_warn(&ssif_info->client->dev,
 813                                  "Invalid response getting flags: %x %x\n",
 814                                  data[0], data[1]);
 815                 } else {
 816                         ssif_inc_stat(ssif_info, flag_fetches);
 817                         ssif_info->msg_flags = data[3];
 818                         handle_flags(ssif_info, flags);
 819                 }
 820                 break;
 821
 822         case SSIF_CLEARING_FLAGS:
 823                 /* We cleared the flags. */
 824                 if ((result < 0) || (len < 3) || (data[2] != 0)) {
 825                         /* Error clearing flags */
 826                         dev_warn(&ssif_info->client->dev,
 827                                  "Error clearing flags: %d %d, %x\n",
 828                                  result, len, (len >= 3) ? data[2] : 0);
 829                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 830                            || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
 831                         dev_warn(&ssif_info->client->dev,
 832                                  "Invalid response clearing flags: %x %x\n",
 833                                  data[0], data[1]);
 834                 }
 835                 ssif_info->ssif_state = SSIF_NORMAL;
 836                 ipmi_ssif_unlock_cond(ssif_info, flags);
 837                 break;
 838
 839         case SSIF_GETTING_EVENTS:
 840                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 841                         /* Error getting event, probably done. */
 842                         msg->done(msg);
 843
 844                         /* Take off the event flag. */
 845                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 846                         handle_flags(ssif_info, flags);
 847                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 848                            || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
 849                         dev_warn(&ssif_info->client->dev,
 850                                  "Invalid response getting events: %x %x\n",
 851                                  msg->rsp[0], msg->rsp[1]);
 852                         msg->done(msg);
 853                         /* Take off the event flag. */
 854                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 855                         handle_flags(ssif_info, flags);
 856                 } else {
 857                         handle_flags(ssif_info, flags);
 858                         ssif_inc_stat(ssif_info, events);
 859                         deliver_recv_msg(ssif_info, msg);
 860                 }
 861                 break;
 862
 863         case SSIF_GETTING_MESSAGES:
 864                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 865                         /* Error getting event, probably done. */
 866                         msg->done(msg);
 867
 868                         /* Take off the msg flag. */
 869                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 870                         handle_flags(ssif_info, flags);
 871                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 872                            || msg->rsp[1] != IPMI_GET_MSG_CMD) {
 873                         dev_warn(&ssif_info->client->dev,
 874                                  "Invalid response clearing flags: %x %x\n",
 875                                  msg->rsp[0], msg->rsp[1]);
 876                         msg->done(msg);
 877
 878                         /* Take off the msg flag. */
 879                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 880                         handle_flags(ssif_info, flags);
 881                 } else {
 882                         ssif_inc_stat(ssif_info, incoming_messages);
 883                         handle_flags(ssif_info, flags);
 884                         deliver_recv_msg(ssif_info, msg);
 885                 }
 886                 break;
 887         }
 888
 889         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 890         if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
 891                 if (ssif_info->req_events)
 892                         start_event_fetch(ssif_info, flags);
 893                 else if (ssif_info->req_flags)
 894                         start_flag_fetch(ssif_info, flags);
 895                 else
 896                         start_next_msg(ssif_info, flags);
 897         } else
 898                 ipmi_ssif_unlock_cond(ssif_info, flags);
 899
 900         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 901                 dev_dbg(&ssif_info->client->dev,
 902                         "DONE 2: state = %d.\n", ssif_info->ssif_state);
 903 }
 904
 905 static void msg_written_handler(struct ssif_info *ssif_info, int result,
 906                                 unsigned char *data, unsigned int len)
 907 {
 908         int rv;
 909
 910         /* We are single-threaded here, so no need for a lock. */
 911         if (result < 0) {
 912                 ssif_info->retries_left--;
 913                 if (ssif_info->retries_left > 0) {
 914                         if (!start_resend(ssif_info)) {
 915                                 ssif_inc_stat(ssif_info, send_retries);
 916                                 return;
 917                         }
 918                         /* request failed, just return the error. */
 919                         ssif_inc_stat(ssif_info, send_errors);
 920
 921                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 922                                 dev_dbg(&ssif_info->client->dev,
 923                                         "%s: Out of retries\n", __func__);
 924                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 925                         return;
 926                 }
 927
 928                 ssif_inc_stat(ssif_info, send_errors);
 929
 930                 /*
 931                  * Got an error on transmit, let the done routine
 932                  * handle it.
 933                  */
 934                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 935                         dev_dbg(&ssif_info->client->dev,
 936                                 "%s: Error  %d\n", __func__, result);
 937
 938                 msg_done_handler(ssif_info, result, NULL, 0);
 939                 return;
 940         }
 941
 942         if (ssif_info->multi_data) {
 943                 /*
 944                  * In the middle of a multi-data write.  See the comment
 945                  * in the SSIF_MULTI_n_PART case in the probe function
 946                  * for details on the intricacies of this.
 947                  */
 948                 int left, to_write;
 949                 unsigned char *data_to_send;
 950                 unsigned char cmd;
 951
 952                 ssif_inc_stat(ssif_info, sent_messages_parts);
 953
 954                 left = ssif_info->multi_len - ssif_info->multi_pos;
 955                 to_write = left;
 956                 if (to_write > 32)
 957                         to_write = 32;
 958                 /* Length byte. */
 959                 ssif_info->multi_data[ssif_info->multi_pos] = to_write;
 960                 data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
 961                 ssif_info->multi_pos += to_write;
 962                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE;
 963                 if (ssif_info->cmd8_works) {
 964                         if (left == to_write) {
 965                                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_END;
 966                                 ssif_info->multi_data = NULL;
 967                         }
 968                 } else if (to_write < 32) {
 969                         ssif_info->multi_data = NULL;
 970                 }
 971
 972                 rv = ssif_i2c_send(ssif_info, msg_written_handler,
 973                                    I2C_SMBUS_WRITE, cmd,
 974                                    data_to_send, I2C_SMBUS_BLOCK_DATA);
 975                 if (rv < 0) {
 976                         /* request failed, just return the error. */
 977                         ssif_inc_stat(ssif_info, send_errors);
 978
 979                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 980                                 dev_dbg(&ssif_info->client->dev,
 981                                         "Error from i2c_non_blocking_op(3)\n");
 982                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 983                 }
 984         } else {
 985                 /* Ready to request the result. */
 986                 unsigned long oflags, *flags;
 987
 988                 ssif_inc_stat(ssif_info, sent_messages);
 989                 ssif_inc_stat(ssif_info, sent_messages_parts);
 990
 991                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 992                 if (ssif_info->got_alert) {
 993                         /* The result is already ready, just start it. */
 994                         ssif_info->got_alert = false;
 995                         ipmi_ssif_unlock_cond(ssif_info, flags);
 996                         start_get(ssif_info);
 997                 } else {
 998                         /* Wait a jiffie then request the next message */
 999                         ssif_info->waiting_alert = true;
1000                         ssif_info->retries_left = SSIF_RECV_RETRIES;
1001                         ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
1002                         if (!ssif_info->stopping)
1003                                 mod_timer(&ssif_info->retry_timer,
1004                                           jiffies + SSIF_MSG_PART_JIFFIES);
1005                         ipmi_ssif_unlock_cond(ssif_info, flags);
1006                 }
1007         }
1008 }
1009
1010 static int start_resend(struct ssif_info *ssif_info)
1011 {
1012         int rv;
1013         int command;
1014
1015         ssif_info->got_alert = false;
1016
1017         if (ssif_info->data_len > 32) {
1018                 command = SSIF_IPMI_MULTI_PART_REQUEST_START;
1019                 ssif_info->multi_data = ssif_info->data;
1020                 ssif_info->multi_len = ssif_info->data_len;
1021                 /*
1022                  * Subtle thing, this is 32, not 33, because we will
1023                  * overwrite the thing at position 32 (which was just
1024                  * transmitted) with the new length.
1025                  */
1026                 ssif_info->multi_pos = 32;
1027                 ssif_info->data[0] = 32;
1028         } else {
1029                 ssif_info->multi_data = NULL;
1030                 command = SSIF_IPMI_REQUEST;
1031                 ssif_info->data[0] = ssif_info->data_len;
1032         }
1033
1034         rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
1035                           command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
1036         if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
1037                 dev_dbg(&ssif_info->client->dev,
1038                         "Error from i2c_non_blocking_op(4)\n");
1039         return rv;
1040 }
1041
1042 static int start_send(struct ssif_info *ssif_info,
1043                       unsigned char   *data,
1044                       unsigned int    len)
1045 {
1046         if (len > IPMI_MAX_MSG_LENGTH)
1047                 return -E2BIG;
1048         if (len > ssif_info->max_xmit_msg_size)
1049                 return -E2BIG;
1050
1051         ssif_info->retries_left = SSIF_SEND_RETRIES;
1052         memcpy(ssif_info->data + 1, data, len);
1053         ssif_info->data_len = len;
1054         return start_resend(ssif_info);
1055 }
1056
1057 /* Must be called with the message lock held. */
1058 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
1059 {
1060         struct ipmi_smi_msg *msg;
1061         unsigned long oflags;
1062
1063  restart:
1064         if (!SSIF_IDLE(ssif_info)) {
1065                 ipmi_ssif_unlock_cond(ssif_info, flags);
1066                 return;
1067         }
1068
1069         if (!ssif_info->waiting_msg) {
1070                 ssif_info->curr_msg = NULL;
1071                 ipmi_ssif_unlock_cond(ssif_info, flags);
1072         } else {
1073                 int rv;
1074
1075                 ssif_info->curr_msg = ssif_info->waiting_msg;
1076                 ssif_info->waiting_msg = NULL;
1077                 ipmi_ssif_unlock_cond(ssif_info, flags);
1078                 rv = start_send(ssif_info,
1079                                 ssif_info->curr_msg->data,
1080                                 ssif_info->curr_msg->data_size);
1081                 if (rv) {
1082                         msg = ssif_info->curr_msg;
1083                         ssif_info->curr_msg = NULL;
1084                         return_hosed_msg(ssif_info, msg);
1085                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1086                         goto restart;
1087                 }
1088         }
1089 }
1090
1091 static void sender(void                *send_info,
1092                    struct ipmi_smi_msg *msg)
1093 {
1094         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1095         unsigned long oflags, *flags;
1096
1097         BUG_ON(ssif_info->waiting_msg);
1098         ssif_info->waiting_msg = msg;
1099
1100         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1101         start_next_msg(ssif_info, flags);
1102
1103         if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1104                 struct timespec64 t;
1105
1106                 ktime_get_real_ts64(&t);
1107                 dev_dbg(&ssif_info->client->dev,
1108                         "**Enqueue %02x %02x: %lld.%6.6ld\n",
1109                         msg->data[0], msg->data[1],
1110                         (long long)t.tv_sec, (long)t.tv_nsec / NSEC_PER_USEC);
1111         }
1112 }
1113
1114 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1115 {
1116         struct ssif_info *ssif_info = send_info;
1117
1118         data->addr_src = ssif_info->addr_source;
1119         data->dev = &ssif_info->client->dev;
1120         data->addr_info = ssif_info->addr_info;
1121         get_device(data->dev);
1122
1123         return 0;
1124 }
1125
1126 /*
1127  * Upper layer wants us to request events.
1128  */
1129 static void request_events(void *send_info)
1130 {
1131         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1132         unsigned long oflags, *flags;
1133
1134         if (!ssif_info->has_event_buffer)
1135                 return;
1136
1137         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1138         ssif_info->req_events = true;
1139         ipmi_ssif_unlock_cond(ssif_info, flags);
1140 }
1141
1142 /*
1143  * Upper layer is changing the flag saying whether we need to request
1144  * flags periodically or not.
1145  */
1146 static void ssif_set_need_watch(void *send_info, unsigned int watch_mask)
1147 {
1148         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1149         unsigned long oflags, *flags;
1150         long timeout = 0;
1151
1152         if (watch_mask & IPMI_WATCH_MASK_CHECK_MESSAGES)
1153                 timeout = SSIF_WATCH_MSG_TIMEOUT;
1154         else if (watch_mask)
1155                 timeout = SSIF_WATCH_WATCHDOG_TIMEOUT;
1156
1157         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1158         if (timeout != ssif_info->watch_timeout) {
1159                 ssif_info->watch_timeout = timeout;
1160                 if (ssif_info->watch_timeout)
1161                         mod_timer(&ssif_info->watch_timer,
1162                                   jiffies + ssif_info->watch_timeout);
1163         }
1164         ipmi_ssif_unlock_cond(ssif_info, flags);
1165 }
1166
1167 static int ssif_start_processing(void            *send_info,
1168                                  struct ipmi_smi *intf)
1169 {
1170         struct ssif_info *ssif_info = send_info;
1171
1172         ssif_info->intf = intf;
1173
1174         return 0;
1175 }
1176
1177 #define MAX_SSIF_BMCS 4
1178
1179 static unsigned short addr[MAX_SSIF_BMCS];
1180 static int num_addrs;
1181 module_param_array(addr, ushort, &num_addrs, 0);
1182 MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1183
1184 static char *adapter_name[MAX_SSIF_BMCS];
1185 static int num_adapter_names;
1186 module_param_array(adapter_name, charp, &num_adapter_names, 0);
1187 MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1188
1189 static int slave_addrs[MAX_SSIF_BMCS];
1190 static int num_slave_addrs;
1191 module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1192 MODULE_PARM_DESC(slave_addrs,
1193                  "The default IPMB slave address for the controller.");
1194
1195 static bool alerts_broken;
1196 module_param(alerts_broken, bool, 0);
1197 MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1198
1199 /*
1200  * Bit 0 enables message debugging, bit 1 enables state debugging, and
1201  * bit 2 enables timing debugging.  This is an array indexed by
1202  * interface number"
1203  */
1204 static int dbg[MAX_SSIF_BMCS];
1205 static int num_dbg;
1206 module_param_array(dbg, int, &num_dbg, 0);
1207 MODULE_PARM_DESC(dbg, "Turn on debugging.");
1208
1209 static bool ssif_dbg_probe;
1210 module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1211 MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1212
1213 static bool ssif_tryacpi = true;
1214 module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1215 MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1216
1217 static bool ssif_trydmi = true;
1218 module_param_named(trydmi, ssif_trydmi, bool, 0);
1219 MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1220
1221 static DEFINE_MUTEX(ssif_infos_mutex);
1222 static LIST_HEAD(ssif_infos);
1223
1224 #define IPMI_SSIF_ATTR(name) \
1225 static ssize_t ipmi_##name##_show(struct device *dev,                   \
1226                                   struct device_attribute *attr,        \
1227                                   char *buf)                            \
1228 {                                                                       \
1229         struct ssif_info *ssif_info = dev_get_drvdata(dev);             \
1230                                                                         \
1231         return snprintf(buf, 10, "%u\n", ssif_get_stat(ssif_info, name));\
1232 }                                                                       \
1233 static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL)
1234
1235 static ssize_t ipmi_type_show(struct device *dev,
1236                               struct device_attribute *attr,
1237                               char *buf)
1238 {
1239         return snprintf(buf, 10, "ssif\n");
1240 }
1241 static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL);
1242
1243 IPMI_SSIF_ATTR(sent_messages);
1244 IPMI_SSIF_ATTR(sent_messages_parts);
1245 IPMI_SSIF_ATTR(send_retries);
1246 IPMI_SSIF_ATTR(send_errors);
1247 IPMI_SSIF_ATTR(received_messages);
1248 IPMI_SSIF_ATTR(received_message_parts);
1249 IPMI_SSIF_ATTR(receive_retries);
1250 IPMI_SSIF_ATTR(receive_errors);
1251 IPMI_SSIF_ATTR(flag_fetches);
1252 IPMI_SSIF_ATTR(hosed);
1253 IPMI_SSIF_ATTR(events);
1254 IPMI_SSIF_ATTR(watchdog_pretimeouts);
1255 IPMI_SSIF_ATTR(alerts);
1256
1257 static struct attribute *ipmi_ssif_dev_attrs[] = {
1258         &dev_attr_type.attr,
1259         &dev_attr_sent_messages.attr,
1260         &dev_attr_sent_messages_parts.attr,
1261         &dev_attr_send_retries.attr,
1262         &dev_attr_send_errors.attr,
1263         &dev_attr_received_messages.attr,
1264         &dev_attr_received_message_parts.attr,
1265         &dev_attr_receive_retries.attr,
1266         &dev_attr_receive_errors.attr,
1267         &dev_attr_flag_fetches.attr,
1268         &dev_attr_hosed.attr,
1269         &dev_attr_events.attr,
1270         &dev_attr_watchdog_pretimeouts.attr,
1271         &dev_attr_alerts.attr,
1272         NULL
1273 };
1274
1275 static const struct attribute_group ipmi_ssif_dev_attr_group = {
1276         .attrs          = ipmi_ssif_dev_attrs,
1277 };
1278
1279 static void shutdown_ssif(void *send_info)
1280 {
1281         struct ssif_info *ssif_info = send_info;
1282
1283         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1284         dev_set_drvdata(&ssif_info->client->dev, NULL);
1285
1286         /* make sure the driver is not looking for flags any more. */
1287         while (ssif_info->ssif_state != SSIF_NORMAL)
1288                 schedule_timeout(1);
1289
1290         ssif_info->stopping = true;
1291         del_timer_sync(&ssif_info->watch_timer);
1292         del_timer_sync(&ssif_info->retry_timer);
1293         if (ssif_info->thread) {
1294                 complete(&ssif_info->wake_thread);
1295                 kthread_stop(ssif_info->thread);
1296         }
1297 }
1298
1299 static int ssif_remove(struct i2c_client *client)
1300 {
1301         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1302         struct ssif_addr_info *addr_info;
1303
1304         if (!ssif_info)
1305                 return 0;
1306
1307         /*
1308          * After this point, we won't deliver anything asychronously
1309          * to the message handler.  We can unregister ourself.
1310          */
1311         ipmi_unregister_smi(ssif_info->intf);
1312
1313         list_for_each_entry(addr_info, &ssif_infos, link) {
1314                 if (addr_info->client == client) {
1315                         addr_info->client = NULL;
1316                         break;
1317                 }
1318         }
1319
1320         kfree(ssif_info);
1321
1322         return 0;
1323 }
1324
1325 static int read_response(struct i2c_client *client, unsigned char *resp)
1326 {
1327         int ret = -ENODEV, retry_cnt = SSIF_RECV_RETRIES;
1328
1329         while (retry_cnt > 0) {
1330                 ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1331                                                 resp);
1332                 if (ret > 0)
1333                         break;
1334                 msleep(SSIF_MSG_MSEC);
1335                 retry_cnt--;
1336                 if (retry_cnt <= 0)
1337                         break;
1338         }
1339
1340         return ret;
1341 }
1342
1343 static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1344                   int *resp_len, unsigned char *resp)
1345 {
1346         int retry_cnt;
1347         int ret;
1348
1349         retry_cnt = SSIF_SEND_RETRIES;
1350  retry1:
1351         ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1352         if (ret) {
1353                 retry_cnt--;
1354                 if (retry_cnt > 0)
1355                         goto retry1;
1356                 return -ENODEV;
1357         }
1358
1359         ret = read_response(client, resp);
1360         if (ret > 0) {
1361                 /* Validate that the response is correct. */
1362                 if (ret < 3 ||
1363                     (resp[0] != (msg[0] | (1 << 2))) ||
1364                     (resp[1] != msg[1]))
1365                         ret = -EINVAL;
1366                 else if (ret > IPMI_MAX_MSG_LENGTH) {
1367                         ret = -E2BIG;
1368                 } else {
1369                         *resp_len = ret;
1370                         ret = 0;
1371                 }
1372         }
1373
1374         return ret;
1375 }
1376
1377 static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1378 {
1379         unsigned char *resp;
1380         unsigned char msg[3];
1381         int           rv;
1382         int           len;
1383
1384         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1385         if (!resp)
1386                 return -ENOMEM;
1387
1388         /* Do a Get Device ID command, since it is required. */
1389         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1390         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1391         rv = do_cmd(client, 2, msg, &len, resp);
1392         if (rv)
1393                 rv = -ENODEV;
1394         else
1395                 strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1396         kfree(resp);
1397         return rv;
1398 }
1399
1400 static int strcmp_nospace(char *s1, char *s2)
1401 {
1402         while (*s1 && *s2) {
1403                 while (isspace(*s1))
1404                         s1++;
1405                 while (isspace(*s2))
1406                         s2++;
1407                 if (*s1 > *s2)
1408                         return 1;
1409                 if (*s1 < *s2)
1410                         return -1;
1411                 s1++;
1412                 s2++;
1413         }
1414         return 0;
1415 }
1416
1417 static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1418                                              char *adapter_name,
1419                                              bool match_null_name)
1420 {
1421         struct ssif_addr_info *info, *found = NULL;
1422
1423 restart:
1424         list_for_each_entry(info, &ssif_infos, link) {
1425                 if (info->binfo.addr == addr) {
1426                         if (info->adapter_name || adapter_name) {
1427                                 if (!info->adapter_name != !adapter_name) {
1428                                         /* One is NULL and one is not */
1429                                         continue;
1430                                 }
1431                                 if (adapter_name &&
1432                                     strcmp_nospace(info->adapter_name,
1433                                                    adapter_name))
1434                                         /* Names do not match */
1435                                         continue;
1436                         }
1437                         found = info;
1438                         break;
1439                 }
1440         }
1441
1442         if (!found && match_null_name) {
1443                 /* Try to get an exact match first, then try with a NULL name */
1444                 adapter_name = NULL;
1445                 match_null_name = false;
1446                 goto restart;
1447         }
1448
1449         return found;
1450 }
1451
1452 static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1453 {
1454 #ifdef CONFIG_ACPI
1455         acpi_handle acpi_handle;
1456
1457         acpi_handle = ACPI_HANDLE(dev);
1458         if (acpi_handle) {
1459                 ssif_info->addr_source = SI_ACPI;
1460                 ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1461                 return true;
1462         }
1463 #endif
1464         return false;
1465 }
1466
1467 static int find_slave_address(struct i2c_client *client, int slave_addr)
1468 {
1469 #ifdef CONFIG_IPMI_DMI_DECODE
1470         if (!slave_addr)
1471                 slave_addr = ipmi_dmi_get_slave_addr(
1472                         SI_TYPE_INVALID,
1473                         i2c_adapter_id(client->adapter),
1474                         client->addr);
1475 #endif
1476
1477         return slave_addr;
1478 }
1479
1480 static int start_multipart_test(struct i2c_client *client,
1481                                 unsigned char *msg, bool do_middle)
1482 {
1483         int retry_cnt = SSIF_SEND_RETRIES, ret;
1484
1485 retry_write:
1486         ret = i2c_smbus_write_block_data(client,
1487                                          SSIF_IPMI_MULTI_PART_REQUEST_START,
1488                                          32, msg);
1489         if (ret) {
1490                 retry_cnt--;
1491                 if (retry_cnt > 0)
1492                         goto retry_write;
1493                 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");
1494                 return ret;
1495         }
1496
1497         if (!do_middle)
1498                 return 0;
1499
1500         ret = i2c_smbus_write_block_data(client,
1501                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1502                                          32, msg + 32);
1503         if (ret) {
1504                 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");
1505                 return ret;
1506         }
1507
1508         return 0;
1509 }
1510
1511 static void test_multipart_messages(struct i2c_client *client,
1512                                     struct ssif_info *ssif_info,
1513                                     unsigned char *resp)
1514 {
1515         unsigned char msg[65];
1516         int ret;
1517         bool do_middle;
1518
1519         if (ssif_info->max_xmit_msg_size <= 32)
1520                 return;
1521
1522         do_middle = ssif_info->max_xmit_msg_size > 63;
1523
1524         memset(msg, 0, sizeof(msg));
1525         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1526         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1527
1528         /*
1529          * The specification is all messed up dealing with sending
1530          * multi-part messages.  Per what the specification says, it
1531          * is impossible to send a message that is a multiple of 32
1532          * bytes, except for 32 itself.  It talks about a "start"
1533          * transaction (cmd=6) that must be 32 bytes, "middle"
1534          * transaction (cmd=7) that must be 32 bytes, and an "end"
1535          * transaction.  The "end" transaction is shown as cmd=7 in
1536          * the text, but if that's the case there is no way to
1537          * differentiate between a middle and end part except the
1538          * length being less than 32.  But there is a table at the far
1539          * end of the section (that I had never noticed until someone
1540          * pointed it out to me) that mentions it as cmd=8.
1541          *
1542          * After some thought, I think the example is wrong and the
1543          * end transaction should be cmd=8.  But some systems don't
1544          * implement cmd=8, they use a zero-length end transaction,
1545          * even though that violates the SMBus specification.
1546          *
1547          * So, to work around this, this code tests if cmd=8 works.
1548          * If it does, then we use that.  If not, it tests zero-
1549          * byte end transactions.  If that works, good.  If not,
1550          * we only allow 63-byte transactions max.
1551          */
1552
1553         ret = start_multipart_test(client, msg, do_middle);
1554         if (ret)
1555                 goto out_no_multi_part;
1556
1557         ret = i2c_smbus_write_block_data(client,
1558                                          SSIF_IPMI_MULTI_PART_REQUEST_END,
1559                                          1, msg + 64);
1560
1561         if (!ret)
1562                 ret = read_response(client, resp);
1563
1564         if (ret > 0) {
1565                 /* End transactions work, we are good. */
1566                 ssif_info->cmd8_works = true;
1567                 return;
1568         }
1569
1570         ret = start_multipart_test(client, msg, do_middle);
1571         if (ret) {
1572                 dev_err(&client->dev, "Second multipart test failed.\n");
1573                 goto out_no_multi_part;
1574         }
1575
1576         ret = i2c_smbus_write_block_data(client,
1577                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1578                                          0, msg + 64);
1579         if (!ret)
1580                 ret = read_response(client, resp);
1581         if (ret > 0)
1582                 /* Zero-size end parts work, use those. */
1583                 return;
1584
1585         /* Limit to 63 bytes and use a short middle command to mark the end. */
1586         if (ssif_info->max_xmit_msg_size > 63)
1587                 ssif_info->max_xmit_msg_size = 63;
1588         return;
1589
1590 out_no_multi_part:
1591         ssif_info->max_xmit_msg_size = 32;
1592         return;
1593 }
1594
1595 /*
1596  * Global enables we care about.
1597  */
1598 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1599                              IPMI_BMC_EVT_MSG_INTR)
1600
1601 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1602 {
1603         unsigned char     msg[3];
1604         unsigned char     *resp;
1605         struct ssif_info   *ssif_info;
1606         int               rv = 0;
1607         int               len;
1608         int               i;
1609         u8                slave_addr = 0;
1610         struct ssif_addr_info *addr_info = NULL;
1611
1612         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1613         if (!resp)
1614                 return -ENOMEM;
1615
1616         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1617         if (!ssif_info) {
1618                 kfree(resp);
1619                 return -ENOMEM;
1620         }
1621
1622         if (!check_acpi(ssif_info, &client->dev)) {
1623                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1624                                            true);
1625                 if (!addr_info) {
1626                         /* Must have come in through sysfs. */
1627                         ssif_info->addr_source = SI_HOTMOD;
1628                 } else {
1629                         ssif_info->addr_source = addr_info->addr_src;
1630                         ssif_info->ssif_debug = addr_info->debug;
1631                         ssif_info->addr_info = addr_info->addr_info;
1632                         addr_info->client = client;
1633                         slave_addr = addr_info->slave_addr;
1634                 }
1635         }
1636
1637         slave_addr = find_slave_address(client, slave_addr);
1638
1639         dev_info(&client->dev,
1640                  "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1641                 ipmi_addr_src_to_str(ssif_info->addr_source),
1642                 client->addr, client->adapter->name, slave_addr);
1643
1644         ssif_info->client = client;
1645         i2c_set_clientdata(client, ssif_info);
1646
1647         /* Now check for system interface capabilities */
1648         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1649         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1650         msg[2] = 0; /* SSIF */
1651         rv = do_cmd(client, 3, msg, &len, resp);
1652         if (!rv && (len >= 3) && (resp[2] == 0)) {
1653                 if (len < 7) {
1654                         if (ssif_dbg_probe)
1655                                 dev_dbg(&ssif_info->client->dev,
1656                                         "SSIF info too short: %d\n", len);
1657                         goto no_support;
1658                 }
1659
1660                 /* Got a good SSIF response, handle it. */
1661                 ssif_info->max_xmit_msg_size = resp[5];
1662                 ssif_info->max_recv_msg_size = resp[6];
1663                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1664                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1665
1666                 /* Sanitize the data */
1667                 switch (ssif_info->multi_support) {
1668                 case SSIF_NO_MULTI:
1669                         if (ssif_info->max_xmit_msg_size > 32)
1670                                 ssif_info->max_xmit_msg_size = 32;
1671                         if (ssif_info->max_recv_msg_size > 32)
1672                                 ssif_info->max_recv_msg_size = 32;
1673                         break;
1674
1675                 case SSIF_MULTI_2_PART:
1676                         if (ssif_info->max_xmit_msg_size > 63)
1677                                 ssif_info->max_xmit_msg_size = 63;
1678                         if (ssif_info->max_recv_msg_size > 62)
1679                                 ssif_info->max_recv_msg_size = 62;
1680                         break;
1681
1682                 case SSIF_MULTI_n_PART:
1683                         /* We take whatever size given, but do some testing. */
1684                         break;
1685
1686                 default:
1687                         /* Data is not sane, just give up. */
1688                         goto no_support;
1689                 }
1690         } else {
1691  no_support:
1692                 /* Assume no multi-part or PEC support */
1693                 dev_info(&ssif_info->client->dev,
1694                          "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1695                         rv, len, resp[2]);
1696
1697                 ssif_info->max_xmit_msg_size = 32;
1698                 ssif_info->max_recv_msg_size = 32;
1699                 ssif_info->multi_support = SSIF_NO_MULTI;
1700                 ssif_info->supports_pec = 0;
1701         }
1702
1703         test_multipart_messages(client, ssif_info, resp);
1704
1705         /* Make sure the NMI timeout is cleared. */
1706         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1707         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1708         msg[2] = WDT_PRE_TIMEOUT_INT;
1709         rv = do_cmd(client, 3, msg, &len, resp);
1710         if (rv || (len < 3) || (resp[2] != 0))
1711                 dev_warn(&ssif_info->client->dev,
1712                          "Unable to clear message flags: %d %d %2.2x\n",
1713                          rv, len, resp[2]);
1714
1715         /* Attempt to enable the event buffer. */
1716         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1717         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1718         rv = do_cmd(client, 2, msg, &len, resp);
1719         if (rv || (len < 4) || (resp[2] != 0)) {
1720                 dev_warn(&ssif_info->client->dev,
1721                          "Error getting global enables: %d %d %2.2x\n",
1722                          rv, len, resp[2]);
1723                 rv = 0; /* Not fatal */
1724                 goto found;
1725         }
1726
1727         ssif_info->global_enables = resp[3];
1728
1729         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1730                 ssif_info->has_event_buffer = true;
1731                 /* buffer is already enabled, nothing to do. */
1732                 goto found;
1733         }
1734
1735         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1736         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1737         msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1738         rv = do_cmd(client, 3, msg, &len, resp);
1739         if (rv || (len < 2)) {
1740                 dev_warn(&ssif_info->client->dev,
1741                          "Error setting global enables: %d %d %2.2x\n",
1742                          rv, len, resp[2]);
1743                 rv = 0; /* Not fatal */
1744                 goto found;
1745         }
1746
1747         if (resp[2] == 0) {
1748                 /* A successful return means the event buffer is supported. */
1749                 ssif_info->has_event_buffer = true;
1750                 ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1751         }
1752
1753         /* Some systems don't behave well if you enable alerts. */
1754         if (alerts_broken)
1755                 goto found;
1756
1757         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1758         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1759         msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1760         rv = do_cmd(client, 3, msg, &len, resp);
1761         if (rv || (len < 2)) {
1762                 dev_warn(&ssif_info->client->dev,
1763                          "Error setting global enables: %d %d %2.2x\n",
1764                          rv, len, resp[2]);
1765                 rv = 0; /* Not fatal */
1766                 goto found;
1767         }
1768
1769         if (resp[2] == 0) {
1770                 /* A successful return means the alert is supported. */
1771                 ssif_info->supports_alert = true;
1772                 ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1773         }
1774
1775  found:
1776         if (ssif_dbg_probe) {
1777                 dev_dbg(&ssif_info->client->dev,
1778                        "%s: i2c_probe found device at i2c address %x\n",
1779                        __func__, client->addr);
1780         }
1781
1782         spin_lock_init(&ssif_info->lock);
1783         ssif_info->ssif_state = SSIF_NORMAL;
1784         timer_setup(&ssif_info->retry_timer, retry_timeout, 0);
1785         timer_setup(&ssif_info->watch_timer, watch_timeout, 0);
1786
1787         for (i = 0; i < SSIF_NUM_STATS; i++)
1788                 atomic_set(&ssif_info->stats[i], 0);
1789
1790         if (ssif_info->supports_pec)
1791                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1792
1793         ssif_info->handlers.owner = THIS_MODULE;
1794         ssif_info->handlers.start_processing = ssif_start_processing;
1795         ssif_info->handlers.shutdown = shutdown_ssif;
1796         ssif_info->handlers.get_smi_info = get_smi_info;
1797         ssif_info->handlers.sender = sender;
1798         ssif_info->handlers.request_events = request_events;
1799         ssif_info->handlers.set_need_watch = ssif_set_need_watch;
1800
1801         {
1802                 unsigned int thread_num;
1803
1804                 thread_num = ((i2c_adapter_id(ssif_info->client->adapter)
1805                                << 8) |
1806                               ssif_info->client->addr);
1807                 init_completion(&ssif_info->wake_thread);
1808                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1809                                                "kssif%4.4x", thread_num);
1810                 if (IS_ERR(ssif_info->thread)) {
1811                         rv = PTR_ERR(ssif_info->thread);
1812                         dev_notice(&ssif_info->client->dev,
1813                                    "Could not start kernel thread: error %d\n",
1814                                    rv);
1815                         goto out;
1816                 }
1817         }
1818
1819         dev_set_drvdata(&ssif_info->client->dev, ssif_info);
1820         rv = device_add_group(&ssif_info->client->dev,
1821                               &ipmi_ssif_dev_attr_group);
1822         if (rv) {
1823                 dev_err(&ssif_info->client->dev,
1824                         "Unable to add device attributes: error %d\n",
1825                         rv);
1826                 goto out;
1827         }
1828
1829         rv = ipmi_register_smi(&ssif_info->handlers,
1830                                ssif_info,
1831                                &ssif_info->client->dev,
1832                                slave_addr);
1833         if (rv) {
1834                 dev_err(&ssif_info->client->dev,
1835                         "Unable to register device: error %d\n", rv);
1836                 goto out_remove_attr;
1837         }
1838
1839  out:
1840         if (rv) {
1841                 if (addr_info)
1842                         addr_info->client = NULL;
1843
1844                 dev_err(&ssif_info->client->dev,
1845                         "Unable to start IPMI SSIF: %d\n", rv);
1846                 kfree(ssif_info);
1847         }
1848         kfree(resp);
1849         return rv;
1850
1851 out_remove_attr:
1852         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1853         dev_set_drvdata(&ssif_info->client->dev, NULL);
1854         goto out;
1855 }
1856
1857 static int ssif_adapter_handler(struct device *adev, void *opaque)
1858 {
1859         struct ssif_addr_info *addr_info = opaque;
1860
1861         if (adev->type != &i2c_adapter_type)
1862                 return 0;
1863
1864         addr_info->added_client = i2c_new_device(to_i2c_adapter(adev),
1865                                                  &addr_info->binfo);
1866
1867         if (!addr_info->adapter_name)
1868                 return 1; /* Only try the first I2C adapter by default. */
1869         return 0;
1870 }
1871
1872 static int new_ssif_client(int addr, char *adapter_name,
1873                            int debug, int slave_addr,
1874                            enum ipmi_addr_src addr_src,
1875                            struct device *dev)
1876 {
1877         struct ssif_addr_info *addr_info;
1878         int rv = 0;
1879
1880         mutex_lock(&ssif_infos_mutex);
1881         if (ssif_info_find(addr, adapter_name, false)) {
1882                 rv = -EEXIST;
1883                 goto out_unlock;
1884         }
1885
1886         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1887         if (!addr_info) {
1888                 rv = -ENOMEM;
1889                 goto out_unlock;
1890         }
1891
1892         if (adapter_name) {
1893                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1894                 if (!addr_info->adapter_name) {
1895                         kfree(addr_info);
1896                         rv = -ENOMEM;
1897                         goto out_unlock;
1898                 }
1899         }
1900
1901         strncpy(addr_info->binfo.type, DEVICE_NAME,
1902                 sizeof(addr_info->binfo.type));
1903         addr_info->binfo.addr = addr;
1904         addr_info->binfo.platform_data = addr_info;
1905         addr_info->debug = debug;
1906         addr_info->slave_addr = slave_addr;
1907         addr_info->addr_src = addr_src;
1908         addr_info->dev = dev;
1909
1910         if (dev)
1911                 dev_set_drvdata(dev, addr_info);
1912
1913         list_add_tail(&addr_info->link, &ssif_infos);
1914
1915         if (initialized)
1916                 i2c_for_each_dev(addr_info, ssif_adapter_handler);
1917         /* Otherwise address list will get it */
1918
1919 out_unlock:
1920         mutex_unlock(&ssif_infos_mutex);
1921         return rv;
1922 }
1923
1924 static void free_ssif_clients(void)
1925 {
1926         struct ssif_addr_info *info, *tmp;
1927
1928         mutex_lock(&ssif_infos_mutex);
1929         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
1930                 list_del(&info->link);
1931                 kfree(info->adapter_name);
1932                 kfree(info);
1933         }
1934         mutex_unlock(&ssif_infos_mutex);
1935 }
1936
1937 static unsigned short *ssif_address_list(void)
1938 {
1939         struct ssif_addr_info *info;
1940         unsigned int count = 0, i = 0;
1941         unsigned short *address_list;
1942
1943         list_for_each_entry(info, &ssif_infos, link)
1944                 count++;
1945
1946         address_list = kcalloc(count + 1, sizeof(*address_list),
1947                                GFP_KERNEL);
1948         if (!address_list)
1949                 return NULL;
1950
1951         list_for_each_entry(info, &ssif_infos, link) {
1952                 unsigned short addr = info->binfo.addr;
1953                 int j;
1954
1955                 for (j = 0; j < i; j++) {
1956                         if (address_list[j] == addr)
1957                                 /* Found a dup. */
1958                                 break;
1959                 }
1960                 if (j == i) /* Didn't find it in the list. */
1961                         address_list[i++] = addr;
1962         }
1963         address_list[i] = I2C_CLIENT_END;
1964
1965         return address_list;
1966 }
1967
1968 #ifdef CONFIG_ACPI
1969 static const struct acpi_device_id ssif_acpi_match[] = {
1970         { "IPI0001", 0 },
1971         { },
1972 };
1973 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
1974 #endif
1975
1976 #ifdef CONFIG_DMI
1977 static int dmi_ipmi_probe(struct platform_device *pdev)
1978 {
1979         u8 slave_addr = 0;
1980         u16 i2c_addr;
1981         int rv;
1982
1983         if (!ssif_trydmi)
1984                 return -ENODEV;
1985
1986         rv = device_property_read_u16(&pdev->dev, "i2c-addr", &i2c_addr);
1987         if (rv) {
1988                 dev_warn(&pdev->dev, "No i2c-addr property\n");
1989                 return -ENODEV;
1990         }
1991
1992         rv = device_property_read_u8(&pdev->dev, "slave-addr", &slave_addr);
1993         if (rv)
1994                 dev_warn(&pdev->dev, "device has no slave-addr property");
1995
1996         return new_ssif_client(i2c_addr, NULL, 0,
1997                                slave_addr, SI_SMBIOS, &pdev->dev);
1998 }
1999 #else
2000 static int dmi_ipmi_probe(struct platform_device *pdev)
2001 {
2002         return -ENODEV;
2003 }
2004 #endif
2005
2006 static const struct i2c_device_id ssif_id[] = {
2007         { DEVICE_NAME, 0 },
2008         { }
2009 };
2010 MODULE_DEVICE_TABLE(i2c, ssif_id);
2011
2012 static struct i2c_driver ssif_i2c_driver = {
2013         .class          = I2C_CLASS_HWMON,
2014         .driver         = {
2015                 .name                   = DEVICE_NAME
2016         },
2017         .probe          = ssif_probe,
2018         .remove         = ssif_remove,
2019         .alert          = ssif_alert,
2020         .id_table       = ssif_id,
2021         .detect         = ssif_detect
2022 };
2023
2024 static int ssif_platform_probe(struct platform_device *dev)
2025 {
2026         return dmi_ipmi_probe(dev);
2027 }
2028
2029 static int ssif_platform_remove(struct platform_device *dev)
2030 {
2031         struct ssif_addr_info *addr_info = dev_get_drvdata(&dev->dev);
2032
2033         if (!addr_info)
2034                 return 0;
2035
2036         mutex_lock(&ssif_infos_mutex);
2037         i2c_unregister_device(addr_info->added_client);
2038
2039         list_del(&addr_info->link);
2040         kfree(addr_info);
2041         mutex_unlock(&ssif_infos_mutex);
2042         return 0;
2043 }
2044
2045 static const struct platform_device_id ssif_plat_ids[] = {
2046     { "dmi-ipmi-ssif", 0 },
2047     { }
2048 };
2049
2050 static struct platform_driver ipmi_driver = {
2051         .driver = {
2052                 .name = DEVICE_NAME,
2053         },
2054         .probe          = ssif_platform_probe,
2055         .remove         = ssif_platform_remove,
2056         .id_table       = ssif_plat_ids
2057 };
2058
2059 static int init_ipmi_ssif(void)
2060 {
2061         int i;
2062         int rv;
2063
2064         if (initialized)
2065                 return 0;
2066
2067         pr_info("IPMI SSIF Interface driver\n");
2068
2069         /* build list for i2c from addr list */
2070         for (i = 0; i < num_addrs; i++) {
2071                 rv = new_ssif_client(addr[i], adapter_name[i],
2072                                      dbg[i], slave_addrs[i],
2073                                      SI_HARDCODED, NULL);
2074                 if (rv)
2075                         pr_err("Couldn't add hardcoded device at addr 0x%x\n",
2076                                addr[i]);
2077         }
2078
2079         if (ssif_tryacpi)
2080                 ssif_i2c_driver.driver.acpi_match_table =
2081                         ACPI_PTR(ssif_acpi_match);
2082
2083         if (ssif_trydmi) {
2084                 rv = platform_driver_register(&ipmi_driver);
2085                 if (rv)
2086                         pr_err("Unable to register driver: %d\n", rv);
2087         }
2088
2089         ssif_i2c_driver.address_list = ssif_address_list();
2090
2091         rv = i2c_add_driver(&ssif_i2c_driver);
2092         if (!rv)
2093                 initialized = true;
2094
2095         return rv;
2096 }
2097 module_init(init_ipmi_ssif);
2098
2099 static void cleanup_ipmi_ssif(void)
2100 {
2101         if (!initialized)
2102                 return;
2103
2104         initialized = false;
2105
2106         i2c_del_driver(&ssif_i2c_driver);
2107
2108         kfree(ssif_i2c_driver.address_list);
2109
2110         platform_driver_unregister(&ipmi_driver);
2111
2112         free_ssif_clients();
2113 }
2114 module_exit(cleanup_ipmi_ssif);
2115
2116 MODULE_ALIAS("platform:dmi-ipmi-ssif");
2117 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2118 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2119 MODULE_LICENSE("GPL");