drivers/char/ipmi/ipmi_ssif.c

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