drivers/misc/mei/interrupt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2003-2018, Intel Corporation. All rights reserved.
   4  * Intel Management Engine Interface (Intel MEI) Linux driver
   5  */
   6
   7 #include <linux/export.h>
   8 #include <linux/kthread.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/fs.h>
  11 #include <linux/jiffies.h>
  12 #include <linux/slab.h>
  13 #include <linux/pm_runtime.h>
  14
  15 #include <linux/mei.h>
  16
  17 #include "mei_dev.h"
  18 #include "hbm.h"
  19 #include "client.h"
  20
  21
  22 /**
  23  * mei_irq_compl_handler - dispatch complete handlers
  24  *      for the completed callbacks
  25  *
  26  * @dev: mei device
  27  * @cmpl_list: list of completed cbs
  28  */
  29 void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list)
  30 {
  31         struct mei_cl_cb *cb, *next;
  32         struct mei_cl *cl;
  33
  34         list_for_each_entry_safe(cb, next, cmpl_list, list) {
  35                 cl = cb->cl;
  36                 list_del_init(&cb->list);
  37
  38                 dev_dbg(dev->dev, "completing call back.\n");
  39                 mei_cl_complete(cl, cb);
  40         }
  41 }
  42 EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
  43
  44 /**
  45  * mei_cl_hbm_equal - check if hbm is addressed to the client
  46  *
  47  * @cl: host client
  48  * @mei_hdr: header of mei client message
  49  *
  50  * Return: true if matches, false otherwise
  51  */
  52 static inline int mei_cl_hbm_equal(struct mei_cl *cl,
  53                         struct mei_msg_hdr *mei_hdr)
  54 {
  55         return  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
  56                 mei_cl_me_id(cl) == mei_hdr->me_addr;
  57 }
  58
  59 /**
  60  * mei_irq_discard_msg  - discard received message
  61  *
  62  * @dev: mei device
  63  * @hdr: message header
  64  * @discard_len: the length of the message to discard (excluding header)
  65  */
  66 static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr,
  67                                 size_t discard_len)
  68 {
  69         if (hdr->dma_ring) {
  70                 mei_dma_ring_read(dev, NULL,
  71                                   hdr->extension[dev->rd_msg_hdr_count - 2]);
  72                 discard_len = 0;
  73         }
  74         /*
  75          * no need to check for size as it is guarantied
  76          * that length fits into rd_msg_buf
  77          */
  78         mei_read_slots(dev, dev->rd_msg_buf, discard_len);
  79         dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
  80                 MEI_HDR_PRM(hdr));
  81 }
  82
  83 /**
  84  * mei_cl_irq_read_msg - process client message
  85  *
  86  * @cl: reading client
  87  * @mei_hdr: header of mei client message
  88  * @meta: extend meta header
  89  * @cmpl_list: completion list
  90  *
  91  * Return: always 0
  92  */
  93 static int mei_cl_irq_read_msg(struct mei_cl *cl,
  94                                struct mei_msg_hdr *mei_hdr,
  95                                struct mei_ext_meta_hdr *meta,
  96                                struct list_head *cmpl_list)
  97 {
  98         struct mei_device *dev = cl->dev;
  99         struct mei_cl_cb *cb;
 100
 101         size_t buf_sz;
 102         u32 length;
 103         int ext_len;
 104
 105         length = mei_hdr->length;
 106         ext_len = 0;
 107         if (mei_hdr->extended) {
 108                 ext_len = sizeof(*meta) + mei_slots2data(meta->size);
 109                 length -= ext_len;
 110         }
 111
 112         cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
 113         if (!cb) {
 114                 if (!mei_cl_is_fixed_address(cl)) {
 115                         cl_err(dev, cl, "pending read cb not found\n");
 116                         goto discard;
 117                 }
 118                 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
 119                 if (!cb)
 120                         goto discard;
 121                 list_add_tail(&cb->list, &cl->rd_pending);
 122         }
 123
 124         if (mei_hdr->extended) {
 125                 struct mei_ext_hdr *ext;
 126                 struct mei_ext_hdr *vtag = NULL;
 127
 128                 ext = mei_ext_begin(meta);
 129                 do {
 130                         switch (ext->type) {
 131                         case MEI_EXT_HDR_VTAG:
 132                                 vtag = ext;
 133                                 break;
 134                         case MEI_EXT_HDR_NONE:
 135                                 fallthrough;
 136                         default:
 137                                 cb->status = -EPROTO;
 138                                 break;
 139                         }
 140
 141                         ext = mei_ext_next(ext);
 142                 } while (!mei_ext_last(meta, ext));
 143
 144                 if (!vtag) {
 145                         cl_dbg(dev, cl, "vtag not found in extended header.\n");
 146                         cb->status = -EPROTO;
 147                         goto discard;
 148                 }
 149
 150                 cl_dbg(dev, cl, "vtag: %d\n", vtag->ext_payload[0]);
 151                 if (cb->vtag && cb->vtag != vtag->ext_payload[0]) {
 152                         cl_err(dev, cl, "mismatched tag: %d != %d\n",
 153                                cb->vtag, vtag->ext_payload[0]);
 154                         cb->status = -EPROTO;
 155                         goto discard;
 156                 }
 157                 cb->vtag = vtag->ext_payload[0];
 158         }
 159
 160         if (!mei_cl_is_connected(cl)) {
 161                 cl_dbg(dev, cl, "not connected\n");
 162                 cb->status = -ENODEV;
 163                 goto discard;
 164         }
 165
 166         if (mei_hdr->dma_ring)
 167                 length = mei_hdr->extension[mei_data2slots(ext_len)];
 168
 169         buf_sz = length + cb->buf_idx;
 170         /* catch for integer overflow */
 171         if (buf_sz < cb->buf_idx) {
 172                 cl_err(dev, cl, "message is too big len %d idx %zu\n",
 173                        length, cb->buf_idx);
 174                 cb->status = -EMSGSIZE;
 175                 goto discard;
 176         }
 177
 178         if (cb->buf.size < buf_sz) {
 179                 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
 180                         cb->buf.size, length, cb->buf_idx);
 181                 cb->status = -EMSGSIZE;
 182                 goto discard;
 183         }
 184
 185         if (mei_hdr->dma_ring) {
 186                 mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length);
 187                 /*  for DMA read 0 length to generate interrupt to the device */
 188                 mei_read_slots(dev, cb->buf.data + cb->buf_idx, 0);
 189         } else {
 190                 mei_read_slots(dev, cb->buf.data + cb->buf_idx, length);
 191         }
 192
 193         cb->buf_idx += length;
 194
 195         if (mei_hdr->msg_complete) {
 196                 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
 197                 list_move_tail(&cb->list, cmpl_list);
 198         } else {
 199                 pm_runtime_mark_last_busy(dev->dev);
 200                 pm_request_autosuspend(dev->dev);
 201         }
 202
 203         return 0;
 204
 205 discard:
 206         if (cb)
 207                 list_move_tail(&cb->list, cmpl_list);
 208         mei_irq_discard_msg(dev, mei_hdr, length);
 209         return 0;
 210 }
 211
 212 /**
 213  * mei_cl_irq_disconnect_rsp - send disconnection response message
 214  *
 215  * @cl: client
 216  * @cb: callback block.
 217  * @cmpl_list: complete list.
 218  *
 219  * Return: 0, OK; otherwise, error.
 220  */
 221 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
 222                                      struct list_head *cmpl_list)
 223 {
 224         struct mei_device *dev = cl->dev;
 225         u32 msg_slots;
 226         int slots;
 227         int ret;
 228
 229         msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
 230         slots = mei_hbuf_empty_slots(dev);
 231         if (slots < 0)
 232                 return -EOVERFLOW;
 233
 234         if ((u32)slots < msg_slots)
 235                 return -EMSGSIZE;
 236
 237         ret = mei_hbm_cl_disconnect_rsp(dev, cl);
 238         list_move_tail(&cb->list, cmpl_list);
 239
 240         return ret;
 241 }
 242
 243 /**
 244  * mei_cl_irq_read - processes client read related operation from the
 245  *      interrupt thread context - request for flow control credits
 246  *
 247  * @cl: client
 248  * @cb: callback block.
 249  * @cmpl_list: complete list.
 250  *
 251  * Return: 0, OK; otherwise, error.
 252  */
 253 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
 254                            struct list_head *cmpl_list)
 255 {
 256         struct mei_device *dev = cl->dev;
 257         u32 msg_slots;
 258         int slots;
 259         int ret;
 260
 261         if (!list_empty(&cl->rd_pending))
 262                 return 0;
 263
 264         msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
 265         slots = mei_hbuf_empty_slots(dev);
 266         if (slots < 0)
 267                 return -EOVERFLOW;
 268
 269         if ((u32)slots < msg_slots)
 270                 return -EMSGSIZE;
 271
 272         ret = mei_hbm_cl_flow_control_req(dev, cl);
 273         if (ret) {
 274                 cl->status = ret;
 275                 cb->buf_idx = 0;
 276                 list_move_tail(&cb->list, cmpl_list);
 277                 return ret;
 278         }
 279
 280         list_move_tail(&cb->list, &cl->rd_pending);
 281
 282         return 0;
 283 }
 284
 285 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
 286 {
 287         return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
 288 }
 289
 290 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
 291 {
 292         return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
 293 }
 294
 295 static inline int hdr_is_valid(u32 msg_hdr)
 296 {
 297         struct mei_msg_hdr *mei_hdr;
 298         u32 expected_len = 0;
 299
 300         mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
 301         if (!msg_hdr || mei_hdr->reserved)
 302                 return -EBADMSG;
 303
 304         if (mei_hdr->dma_ring)
 305                 expected_len += MEI_SLOT_SIZE;
 306         if (mei_hdr->extended)
 307                 expected_len += MEI_SLOT_SIZE;
 308         if (mei_hdr->length < expected_len)
 309                 return -EBADMSG;
 310
 311         return 0;
 312 }
 313
 314 /**
 315  * mei_irq_read_handler - bottom half read routine after ISR to
 316  * handle the read processing.
 317  *
 318  * @dev: the device structure
 319  * @cmpl_list: An instance of our list structure
 320  * @slots: slots to read.
 321  *
 322  * Return: 0 on success, <0 on failure.
 323  */
 324 int mei_irq_read_handler(struct mei_device *dev,
 325                          struct list_head *cmpl_list, s32 *slots)
 326 {
 327         struct mei_msg_hdr *mei_hdr;
 328         struct mei_ext_meta_hdr *meta_hdr = NULL;
 329         struct mei_cl *cl;
 330         int ret;
 331         u32 ext_meta_hdr_u32;
 332         u32 hdr_size_left;
 333         u32 hdr_size_ext;
 334         int i;
 335         int ext_hdr_end;
 336
 337         if (!dev->rd_msg_hdr[0]) {
 338                 dev->rd_msg_hdr[0] = mei_read_hdr(dev);
 339                 dev->rd_msg_hdr_count = 1;
 340                 (*slots)--;
 341                 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
 342
 343                 ret = hdr_is_valid(dev->rd_msg_hdr[0]);
 344                 if (ret) {
 345                         dev_err(dev->dev, "corrupted message header 0x%08X\n",
 346                                 dev->rd_msg_hdr[0]);
 347                         goto end;
 348                 }
 349         }
 350
 351         mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
 352         dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
 353
 354         if (mei_slots2data(*slots) < mei_hdr->length) {
 355                 dev_err(dev->dev, "less data available than length=%08x.\n",
 356                                 *slots);
 357                 /* we can't read the message */
 358                 ret = -ENODATA;
 359                 goto end;
 360         }
 361
 362         ext_hdr_end = 1;
 363         hdr_size_left = mei_hdr->length;
 364
 365         if (mei_hdr->extended) {
 366                 if (!dev->rd_msg_hdr[1]) {
 367                         ext_meta_hdr_u32 = mei_read_hdr(dev);
 368                         dev->rd_msg_hdr[1] = ext_meta_hdr_u32;
 369                         dev->rd_msg_hdr_count++;
 370                         (*slots)--;
 371                         dev_dbg(dev->dev, "extended header is %08x\n",
 372                                 ext_meta_hdr_u32);
 373                 }
 374                 meta_hdr = ((struct mei_ext_meta_hdr *)dev->rd_msg_hdr + 1);
 375                 if (check_add_overflow((u32)sizeof(*meta_hdr),
 376                                        mei_slots2data(meta_hdr->size),
 377                                        &hdr_size_ext)) {
 378                         dev_err(dev->dev, "extended message size too big %d\n",
 379                                 meta_hdr->size);
 380                         return -EBADMSG;
 381                 }
 382                 if (hdr_size_left < hdr_size_ext) {
 383                         dev_err(dev->dev, "corrupted message header len %d\n",
 384                                 mei_hdr->length);
 385                         return -EBADMSG;
 386                 }
 387                 hdr_size_left -= hdr_size_ext;
 388
 389                 ext_hdr_end = meta_hdr->size + 2;
 390                 for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) {
 391                         dev->rd_msg_hdr[i] = mei_read_hdr(dev);
 392                         dev_dbg(dev->dev, "extended header %d is %08x\n", i,
 393                                 dev->rd_msg_hdr[i]);
 394                         dev->rd_msg_hdr_count++;
 395                         (*slots)--;
 396                 }
 397         }
 398
 399         if (mei_hdr->dma_ring) {
 400                 if (hdr_size_left != sizeof(dev->rd_msg_hdr[ext_hdr_end])) {
 401                         dev_err(dev->dev, "corrupted message header len %d\n",
 402                                 mei_hdr->length);
 403                         return -EBADMSG;
 404                 }
 405
 406                 dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev);
 407                 dev->rd_msg_hdr_count++;
 408                 (*slots)--;
 409                 mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]);
 410         }
 411
 412         /*  HBM message */
 413         if (hdr_is_hbm(mei_hdr)) {
 414                 ret = mei_hbm_dispatch(dev, mei_hdr);
 415                 if (ret) {
 416                         dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
 417                                         ret);
 418                         goto end;
 419                 }
 420                 goto reset_slots;
 421         }
 422
 423         /* find recipient cl */
 424         list_for_each_entry(cl, &dev->file_list, link) {
 425                 if (mei_cl_hbm_equal(cl, mei_hdr)) {
 426                         cl_dbg(dev, cl, "got a message\n");
 427                         break;
 428                 }
 429         }
 430
 431         /* if no recipient cl was found we assume corrupted header */
 432         if (&cl->link == &dev->file_list) {
 433                 /* A message for not connected fixed address clients
 434                  * should be silently discarded
 435                  * On power down client may be force cleaned,
 436                  * silently discard such messages
 437                  */
 438                 if (hdr_is_fixed(mei_hdr) ||
 439                     dev->dev_state == MEI_DEV_POWER_DOWN) {
 440                         mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length);
 441                         ret = 0;
 442                         goto reset_slots;
 443                 }
 444                 dev_err(dev->dev, "no destination client found 0x%08X\n",
 445                                 dev->rd_msg_hdr[0]);
 446                 ret = -EBADMSG;
 447                 goto end;
 448         }
 449
 450         ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list);
 451
 452
 453 reset_slots:
 454         /* reset the number of slots and header */
 455         memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
 456         dev->rd_msg_hdr_count = 0;
 457         *slots = mei_count_full_read_slots(dev);
 458         if (*slots == -EOVERFLOW) {
 459                 /* overflow - reset */
 460                 dev_err(dev->dev, "resetting due to slots overflow.\n");
 461                 /* set the event since message has been read */
 462                 ret = -ERANGE;
 463                 goto end;
 464         }
 465 end:
 466         return ret;
 467 }
 468 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
 469
 470
 471 /**
 472  * mei_irq_write_handler -  dispatch write requests
 473  *  after irq received
 474  *
 475  * @dev: the device structure
 476  * @cmpl_list: An instance of our list structure
 477  *
 478  * Return: 0 on success, <0 on failure.
 479  */
 480 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
 481 {
 482
 483         struct mei_cl *cl;
 484         struct mei_cl_cb *cb, *next;
 485         s32 slots;
 486         int ret;
 487
 488
 489         if (!mei_hbuf_acquire(dev))
 490                 return 0;
 491
 492         slots = mei_hbuf_empty_slots(dev);
 493         if (slots < 0)
 494                 return -EOVERFLOW;
 495
 496         if (slots == 0)
 497                 return -EMSGSIZE;
 498
 499         /* complete all waiting for write CB */
 500         dev_dbg(dev->dev, "complete all waiting for write cb.\n");
 501
 502         list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
 503                 cl = cb->cl;
 504
 505                 cl->status = 0;
 506                 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
 507                 cl->writing_state = MEI_WRITE_COMPLETE;
 508                 list_move_tail(&cb->list, cmpl_list);
 509         }
 510
 511         /* complete control write list CB */
 512         dev_dbg(dev->dev, "complete control write list cb.\n");
 513         list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
 514                 cl = cb->cl;
 515                 switch (cb->fop_type) {
 516                 case MEI_FOP_DISCONNECT:
 517                         /* send disconnect message */
 518                         ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
 519                         if (ret)
 520                                 return ret;
 521
 522                         break;
 523                 case MEI_FOP_READ:
 524                         /* send flow control message */
 525                         ret = mei_cl_irq_read(cl, cb, cmpl_list);
 526                         if (ret)
 527                                 return ret;
 528
 529                         break;
 530                 case MEI_FOP_CONNECT:
 531                         /* connect message */
 532                         ret = mei_cl_irq_connect(cl, cb, cmpl_list);
 533                         if (ret)
 534                                 return ret;
 535
 536                         break;
 537                 case MEI_FOP_DISCONNECT_RSP:
 538                         /* send disconnect resp */
 539                         ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
 540                         if (ret)
 541                                 return ret;
 542                         break;
 543
 544                 case MEI_FOP_NOTIFY_START:
 545                 case MEI_FOP_NOTIFY_STOP:
 546                         ret = mei_cl_irq_notify(cl, cb, cmpl_list);
 547                         if (ret)
 548                                 return ret;
 549                         break;
 550                 case MEI_FOP_DMA_MAP:
 551                         ret = mei_cl_irq_dma_map(cl, cb, cmpl_list);
 552                         if (ret)
 553                                 return ret;
 554                         break;
 555                 case MEI_FOP_DMA_UNMAP:
 556                         ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list);
 557                         if (ret)
 558                                 return ret;
 559                         break;
 560                 default:
 561                         BUG();
 562                 }
 563
 564         }
 565         /* complete  write list CB */
 566         dev_dbg(dev->dev, "complete write list cb.\n");
 567         list_for_each_entry_safe(cb, next, &dev->write_list, list) {
 568                 cl = cb->cl;
 569                 ret = mei_cl_irq_write(cl, cb, cmpl_list);
 570                 if (ret)
 571                         return ret;
 572         }
 573         return 0;
 574 }
 575 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
 576
 577
 578 /**
 579  * mei_connect_timeout  - connect/disconnect timeouts
 580  *
 581  * @cl: host client
 582  */
 583 static void mei_connect_timeout(struct mei_cl *cl)
 584 {
 585         struct mei_device *dev = cl->dev;
 586
 587         if (cl->state == MEI_FILE_CONNECTING) {
 588                 if (dev->hbm_f_dot_supported) {
 589                         cl->state = MEI_FILE_DISCONNECT_REQUIRED;
 590                         wake_up(&cl->wait);
 591                         return;
 592                 }
 593         }
 594         mei_reset(dev);
 595 }
 596
 597 #define MEI_STALL_TIMER_FREQ (2 * HZ)
 598 /**
 599  * mei_schedule_stall_timer - re-arm stall_timer work
 600  *
 601  * Schedule stall timer
 602  *
 603  * @dev: the device structure
 604  */
 605 void mei_schedule_stall_timer(struct mei_device *dev)
 606 {
 607         schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
 608 }
 609
 610 /**
 611  * mei_timer - timer function.
 612  *
 613  * @work: pointer to the work_struct structure
 614  *
 615  */
 616 void mei_timer(struct work_struct *work)
 617 {
 618         struct mei_cl *cl;
 619         struct mei_device *dev = container_of(work,
 620                                         struct mei_device, timer_work.work);
 621         bool reschedule_timer = false;
 622
 623         mutex_lock(&dev->device_lock);
 624
 625         /* Catch interrupt stalls during HBM init handshake */
 626         if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
 627             dev->hbm_state != MEI_HBM_IDLE) {
 628
 629                 if (dev->init_clients_timer) {
 630                         if (--dev->init_clients_timer == 0) {
 631                                 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
 632                                         dev->hbm_state);
 633                                 mei_reset(dev);
 634                                 goto out;
 635                         }
 636                         reschedule_timer = true;
 637                 }
 638         }
 639
 640         if (dev->dev_state != MEI_DEV_ENABLED)
 641                 goto out;
 642
 643         /*** connect/disconnect timeouts ***/
 644         list_for_each_entry(cl, &dev->file_list, link) {
 645                 if (cl->timer_count) {
 646                         if (--cl->timer_count == 0) {
 647                                 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
 648                                 mei_connect_timeout(cl);
 649                                 goto out;
 650                         }
 651                         reschedule_timer = true;
 652                 }
 653         }
 654
 655 out:
 656         if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
 657                 mei_schedule_stall_timer(dev);
 658
 659         mutex_unlock(&dev->device_lock);
 660 }