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