drivers/char/ipmi/ipmi_ssif.c

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