drivers/misc/mei/interrupt.c

   1 /*
   2  *
   3  * Intel Management Engine Interface (Intel MEI) Linux driver
   4  * Copyright (c) 2003-2012, Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  */
  16
  17
  18 #include <linux/export.h>
  19 #include <linux/kthread.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/fs.h>
  22 #include <linux/jiffies.h>
  23 #include <linux/slab.h>
  24 #include <linux/pm_runtime.h>
  25
  26 #include <linux/mei.h>
  27
  28 #include "mei_dev.h"
  29 #include "hbm.h"
  30 #include "client.h"
  31
  32
  33 /**
  34  * mei_irq_compl_handler - dispatch complete handlers
  35  *      for the completed callbacks
  36  *
  37  * @dev: mei device
  38  * @cmpl_list: list of completed cbs
  39  */
  40 void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list)
  41 {
  42         struct mei_cl_cb *cb, *next;
  43         struct mei_cl *cl;
  44
  45         list_for_each_entry_safe(cb, next, cmpl_list, list) {
  46                 cl = cb->cl;
  47                 list_del_init(&cb->list);
  48
  49                 dev_dbg(dev->dev, "completing call back.\n");
  50                 mei_cl_complete(cl, cb);
  51         }
  52 }
  53 EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
  54
  55 /**
  56  * mei_cl_hbm_equal - check if hbm is addressed to the client
  57  *
  58  * @cl: host client
  59  * @mei_hdr: header of mei client message
  60  *
  61  * Return: true if matches, false otherwise
  62  */
  63 static inline int mei_cl_hbm_equal(struct mei_cl *cl,
  64                         struct mei_msg_hdr *mei_hdr)
  65 {
  66         return  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
  67                 mei_cl_me_id(cl) == mei_hdr->me_addr;
  68 }
  69
  70 /**
  71  * mei_irq_discard_msg  - discard received message
  72  *
  73  * @dev: mei device
  74  * @hdr: message header
  75  */
  76 static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
  77 {
  78         /*
  79          * no need to check for size as it is guarantied
  80          * that length fits into rd_msg_buf
  81          */
  82         mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
  83         dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
  84                 MEI_HDR_PRM(hdr));
  85 }
  86
  87 /**
  88  * mei_cl_irq_read_msg - process client message
  89  *
  90  * @cl: reading client
  91  * @mei_hdr: header of mei client message
  92  * @cmpl_list: completion list
  93  *
  94  * Return: always 0
  95  */
  96 static int mei_cl_irq_read_msg(struct mei_cl *cl,
  97                                struct mei_msg_hdr *mei_hdr,
  98                                struct list_head *cmpl_list)
  99 {
 100         struct mei_device *dev = cl->dev;
 101         struct mei_cl_cb *cb;
 102         size_t buf_sz;
 103
 104         cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
 105         if (!cb) {
 106                 if (!mei_cl_is_fixed_address(cl)) {
 107                         cl_err(dev, cl, "pending read cb not found\n");
 108                         goto discard;
 109                 }
 110                 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
 111                 if (!cb)
 112                         goto discard;
 113                 list_add_tail(&cb->list, &cl->rd_pending);
 114         }
 115
 116         if (!mei_cl_is_connected(cl)) {
 117                 cl_dbg(dev, cl, "not connected\n");
 118                 cb->status = -ENODEV;
 119                 goto discard;
 120         }
 121
 122         buf_sz = mei_hdr->length + cb->buf_idx;
 123         /* catch for integer overflow */
 124         if (buf_sz < cb->buf_idx) {
 125                 cl_err(dev, cl, "message is too big len %d idx %zu\n",
 126                        mei_hdr->length, cb->buf_idx);
 127                 cb->status = -EMSGSIZE;
 128                 goto discard;
 129         }
 130
 131         if (cb->buf.size < buf_sz) {
 132                 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
 133                         cb->buf.size, mei_hdr->length, cb->buf_idx);
 134                 cb->status = -EMSGSIZE;
 135                 goto discard;
 136         }
 137
 138         mei_read_slots(dev, cb->buf.data + cb->buf_idx, mei_hdr->length);
 139
 140         cb->buf_idx += mei_hdr->length;
 141
 142         if (mei_hdr->msg_complete) {
 143                 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
 144                 list_move_tail(&cb->list, cmpl_list);
 145         } else {
 146                 pm_runtime_mark_last_busy(dev->dev);
 147                 pm_request_autosuspend(dev->dev);
 148         }
 149
 150         return 0;
 151
 152 discard:
 153         if (cb)
 154                 list_move_tail(&cb->list, cmpl_list);
 155         mei_irq_discard_msg(dev, mei_hdr);
 156         return 0;
 157 }
 158
 159 /**
 160  * mei_cl_irq_disconnect_rsp - send disconnection response message
 161  *
 162  * @cl: client
 163  * @cb: callback block.
 164  * @cmpl_list: complete list.
 165  *
 166  * Return: 0, OK; otherwise, error.
 167  */
 168 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
 169                                      struct list_head *cmpl_list)
 170 {
 171         struct mei_device *dev = cl->dev;
 172         u32 msg_slots;
 173         int slots;
 174         int ret;
 175
 176         msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
 177         slots = mei_hbuf_empty_slots(dev);
 178         if (slots < 0)
 179                 return -EOVERFLOW;
 180
 181         if ((u32)slots < msg_slots)
 182                 return -EMSGSIZE;
 183
 184         ret = mei_hbm_cl_disconnect_rsp(dev, cl);
 185         list_move_tail(&cb->list, cmpl_list);
 186
 187         return ret;
 188 }
 189
 190 /**
 191  * mei_cl_irq_read - processes client read related operation from the
 192  *      interrupt thread context - request for flow control credits
 193  *
 194  * @cl: client
 195  * @cb: callback block.
 196  * @cmpl_list: complete list.
 197  *
 198  * Return: 0, OK; otherwise, error.
 199  */
 200 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
 201                            struct list_head *cmpl_list)
 202 {
 203         struct mei_device *dev = cl->dev;
 204         u32 msg_slots;
 205         int slots;
 206         int ret;
 207
 208         if (!list_empty(&cl->rd_pending))
 209                 return 0;
 210
 211         msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
 212         slots = mei_hbuf_empty_slots(dev);
 213         if (slots < 0)
 214                 return -EOVERFLOW;
 215
 216         if ((u32)slots < msg_slots)
 217                 return -EMSGSIZE;
 218
 219         ret = mei_hbm_cl_flow_control_req(dev, cl);
 220         if (ret) {
 221                 cl->status = ret;
 222                 cb->buf_idx = 0;
 223                 list_move_tail(&cb->list, cmpl_list);
 224                 return ret;
 225         }
 226
 227         list_move_tail(&cb->list, &cl->rd_pending);
 228
 229         return 0;
 230 }
 231
 232 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
 233 {
 234         return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
 235 }
 236
 237 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
 238 {
 239         return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
 240 }
 241
 242 static inline int hdr_is_valid(u32 msg_hdr)
 243 {
 244         struct mei_msg_hdr *mei_hdr;
 245
 246         mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
 247         if (!msg_hdr || mei_hdr->reserved)
 248                 return -EBADMSG;
 249
 250         return 0;
 251 }
 252
 253 /**
 254  * mei_irq_read_handler - bottom half read routine after ISR to
 255  * handle the read processing.
 256  *
 257  * @dev: the device structure
 258  * @cmpl_list: An instance of our list structure
 259  * @slots: slots to read.
 260  *
 261  * Return: 0 on success, <0 on failure.
 262  */
 263 int mei_irq_read_handler(struct mei_device *dev,
 264                          struct list_head *cmpl_list, s32 *slots)
 265 {
 266         struct mei_msg_hdr *mei_hdr;
 267         struct mei_cl *cl;
 268         int ret;
 269
 270         if (!dev->rd_msg_hdr) {
 271                 dev->rd_msg_hdr = mei_read_hdr(dev);
 272                 (*slots)--;
 273                 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
 274
 275                 ret = hdr_is_valid(dev->rd_msg_hdr);
 276                 if (ret) {
 277                         dev_err(dev->dev, "corrupted message header 0x%08X\n",
 278                                 dev->rd_msg_hdr);
 279                         goto end;
 280                 }
 281         }
 282
 283         mei_hdr = (struct mei_msg_hdr *)&dev->rd_msg_hdr;
 284         dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
 285
 286         if (mei_slots2data(*slots) < mei_hdr->length) {
 287                 dev_err(dev->dev, "less data available than length=%08x.\n",
 288                                 *slots);
 289                 /* we can't read the message */
 290                 ret = -ENODATA;
 291                 goto end;
 292         }
 293
 294         /*  HBM message */
 295         if (hdr_is_hbm(mei_hdr)) {
 296                 ret = mei_hbm_dispatch(dev, mei_hdr);
 297                 if (ret) {
 298                         dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
 299                                         ret);
 300                         goto end;
 301                 }
 302                 goto reset_slots;
 303         }
 304
 305         /* find recipient cl */
 306         list_for_each_entry(cl, &dev->file_list, link) {
 307                 if (mei_cl_hbm_equal(cl, mei_hdr)) {
 308                         cl_dbg(dev, cl, "got a message\n");
 309                         break;
 310                 }
 311         }
 312
 313         /* if no recipient cl was found we assume corrupted header */
 314         if (&cl->link == &dev->file_list) {
 315                 /* A message for not connected fixed address clients
 316                  * should be silently discarded
 317                  * On power down client may be force cleaned,
 318                  * silently discard such messages
 319                  */
 320                 if (hdr_is_fixed(mei_hdr) ||
 321                     dev->dev_state == MEI_DEV_POWER_DOWN) {
 322                         mei_irq_discard_msg(dev, mei_hdr);
 323                         ret = 0;
 324                         goto reset_slots;
 325                 }
 326                 dev_err(dev->dev, "no destination client found 0x%08X\n",
 327                                 dev->rd_msg_hdr);
 328                 ret = -EBADMSG;
 329                 goto end;
 330         }
 331
 332         ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
 333
 334
 335 reset_slots:
 336         /* reset the number of slots and header */
 337         *slots = mei_count_full_read_slots(dev);
 338         dev->rd_msg_hdr = 0;
 339
 340         if (*slots == -EOVERFLOW) {
 341                 /* overflow - reset */
 342                 dev_err(dev->dev, "resetting due to slots overflow.\n");
 343                 /* set the event since message has been read */
 344                 ret = -ERANGE;
 345                 goto end;
 346         }
 347 end:
 348         return ret;
 349 }
 350 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
 351
 352
 353 /**
 354  * mei_irq_write_handler -  dispatch write requests
 355  *  after irq received
 356  *
 357  * @dev: the device structure
 358  * @cmpl_list: An instance of our list structure
 359  *
 360  * Return: 0 on success, <0 on failure.
 361  */
 362 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
 363 {
 364
 365         struct mei_cl *cl;
 366         struct mei_cl_cb *cb, *next;
 367         s32 slots;
 368         int ret;
 369
 370
 371         if (!mei_hbuf_acquire(dev))
 372                 return 0;
 373
 374         slots = mei_hbuf_empty_slots(dev);
 375         if (slots < 0)
 376                 return -EOVERFLOW;
 377
 378         if (slots == 0)
 379                 return -EMSGSIZE;
 380
 381         /* complete all waiting for write CB */
 382         dev_dbg(dev->dev, "complete all waiting for write cb.\n");
 383
 384         list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
 385                 cl = cb->cl;
 386
 387                 cl->status = 0;
 388                 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
 389                 cl->writing_state = MEI_WRITE_COMPLETE;
 390                 list_move_tail(&cb->list, cmpl_list);
 391         }
 392
 393         /* complete control write list CB */
 394         dev_dbg(dev->dev, "complete control write list cb.\n");
 395         list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
 396                 cl = cb->cl;
 397                 switch (cb->fop_type) {
 398                 case MEI_FOP_DISCONNECT:
 399                         /* send disconnect message */
 400                         ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
 401                         if (ret)
 402                                 return ret;
 403
 404                         break;
 405                 case MEI_FOP_READ:
 406                         /* send flow control message */
 407                         ret = mei_cl_irq_read(cl, cb, cmpl_list);
 408                         if (ret)
 409                                 return ret;
 410
 411                         break;
 412                 case MEI_FOP_CONNECT:
 413                         /* connect message */
 414                         ret = mei_cl_irq_connect(cl, cb, cmpl_list);
 415                         if (ret)
 416                                 return ret;
 417
 418                         break;
 419                 case MEI_FOP_DISCONNECT_RSP:
 420                         /* send disconnect resp */
 421                         ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
 422                         if (ret)
 423                                 return ret;
 424                         break;
 425
 426                 case MEI_FOP_NOTIFY_START:
 427                 case MEI_FOP_NOTIFY_STOP:
 428                         ret = mei_cl_irq_notify(cl, cb, cmpl_list);
 429                         if (ret)
 430                                 return ret;
 431                         break;
 432                 default:
 433                         BUG();
 434                 }
 435
 436         }
 437         /* complete  write list CB */
 438         dev_dbg(dev->dev, "complete write list cb.\n");
 439         list_for_each_entry_safe(cb, next, &dev->write_list, list) {
 440                 cl = cb->cl;
 441                 ret = mei_cl_irq_write(cl, cb, cmpl_list);
 442                 if (ret)
 443                         return ret;
 444         }
 445         return 0;
 446 }
 447 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
 448
 449
 450 /**
 451  * mei_connect_timeout  - connect/disconnect timeouts
 452  *
 453  * @cl: host client
 454  */
 455 static void mei_connect_timeout(struct mei_cl *cl)
 456 {
 457         struct mei_device *dev = cl->dev;
 458
 459         if (cl->state == MEI_FILE_CONNECTING) {
 460                 if (dev->hbm_f_dot_supported) {
 461                         cl->state = MEI_FILE_DISCONNECT_REQUIRED;
 462                         wake_up(&cl->wait);
 463                         return;
 464                 }
 465         }
 466         mei_reset(dev);
 467 }
 468
 469 #define MEI_STALL_TIMER_FREQ (2 * HZ)
 470 /**
 471  * mei_schedule_stall_timer - re-arm stall_timer work
 472  *
 473  * Schedule stall timer
 474  *
 475  * @dev: the device structure
 476  */
 477 void mei_schedule_stall_timer(struct mei_device *dev)
 478 {
 479         schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
 480 }
 481
 482 /**
 483  * mei_timer - timer function.
 484  *
 485  * @work: pointer to the work_struct structure
 486  *
 487  */
 488 void mei_timer(struct work_struct *work)
 489 {
 490         struct mei_cl *cl;
 491         struct mei_device *dev = container_of(work,
 492                                         struct mei_device, timer_work.work);
 493         bool reschedule_timer = false;
 494
 495         mutex_lock(&dev->device_lock);
 496
 497         /* Catch interrupt stalls during HBM init handshake */
 498         if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
 499             dev->hbm_state != MEI_HBM_IDLE) {
 500
 501                 if (dev->init_clients_timer) {
 502                         if (--dev->init_clients_timer == 0) {
 503                                 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
 504                                         dev->hbm_state);
 505                                 mei_reset(dev);
 506                                 goto out;
 507                         }
 508                         reschedule_timer = true;
 509                 }
 510         }
 511
 512         if (dev->dev_state != MEI_DEV_ENABLED)
 513                 goto out;
 514
 515         /*** connect/disconnect timeouts ***/
 516         list_for_each_entry(cl, &dev->file_list, link) {
 517                 if (cl->timer_count) {
 518                         if (--cl->timer_count == 0) {
 519                                 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
 520                                 mei_connect_timeout(cl);
 521                                 goto out;
 522                         }
 523                         reschedule_timer = true;
 524                 }
 525         }
 526
 527 out:
 528         if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
 529                 mei_schedule_stall_timer(dev);
 530
 531         mutex_unlock(&dev->device_lock);
 532 }