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         pm_runtime_mark_last_busy(dev->dev);
 281         pm_request_autosuspend(dev->dev);
 282
 283         list_move_tail(&cb->list, &cl->rd_pending);
 284
 285         return 0;
 286 }
 287
 288 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
 289 {
 290         return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
 291 }
 292
 293 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
 294 {
 295         return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
 296 }
 297
 298 static inline int hdr_is_valid(u32 msg_hdr)
 299 {
 300         struct mei_msg_hdr *mei_hdr;
 301         u32 expected_len = 0;
 302
 303         mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
 304         if (!msg_hdr || mei_hdr->reserved)
 305                 return -EBADMSG;
 306
 307         if (mei_hdr->dma_ring)
 308                 expected_len += MEI_SLOT_SIZE;
 309         if (mei_hdr->extended)
 310                 expected_len += MEI_SLOT_SIZE;
 311         if (mei_hdr->length < expected_len)
 312                 return -EBADMSG;
 313
 314         return 0;
 315 }
 316
 317 /**
 318  * mei_irq_read_handler - bottom half read routine after ISR to
 319  * handle the read processing.
 320  *
 321  * @dev: the device structure
 322  * @cmpl_list: An instance of our list structure
 323  * @slots: slots to read.
 324  *
 325  * Return: 0 on success, <0 on failure.
 326  */
 327 int mei_irq_read_handler(struct mei_device *dev,
 328                          struct list_head *cmpl_list, s32 *slots)
 329 {
 330         struct mei_msg_hdr *mei_hdr;
 331         struct mei_ext_meta_hdr *meta_hdr = NULL;
 332         struct mei_cl *cl;
 333         int ret;
 334         u32 ext_meta_hdr_u32;
 335         u32 hdr_size_left;
 336         u32 hdr_size_ext;
 337         int i;
 338         int ext_hdr_end;
 339
 340         if (!dev->rd_msg_hdr[0]) {
 341                 dev->rd_msg_hdr[0] = mei_read_hdr(dev);
 342                 dev->rd_msg_hdr_count = 1;
 343                 (*slots)--;
 344                 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
 345
 346                 ret = hdr_is_valid(dev->rd_msg_hdr[0]);
 347                 if (ret) {
 348                         dev_err(dev->dev, "corrupted message header 0x%08X\n",
 349                                 dev->rd_msg_hdr[0]);
 350                         goto end;
 351                 }
 352         }
 353
 354         mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
 355         dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
 356
 357         if (mei_slots2data(*slots) < mei_hdr->length) {
 358                 dev_err(dev->dev, "less data available than length=%08x.\n",
 359                                 *slots);
 360                 /* we can't read the message */
 361                 ret = -ENODATA;
 362                 goto end;
 363         }
 364
 365         ext_hdr_end = 1;
 366         hdr_size_left = mei_hdr->length;
 367
 368         if (mei_hdr->extended) {
 369                 if (!dev->rd_msg_hdr[1]) {
 370                         ext_meta_hdr_u32 = mei_read_hdr(dev);
 371                         dev->rd_msg_hdr[1] = ext_meta_hdr_u32;
 372                         dev->rd_msg_hdr_count++;
 373                         (*slots)--;
 374                         dev_dbg(dev->dev, "extended header is %08x\n",
 375                                 ext_meta_hdr_u32);
 376                 }
 377                 meta_hdr = ((struct mei_ext_meta_hdr *)dev->rd_msg_hdr + 1);
 378                 if (check_add_overflow((u32)sizeof(*meta_hdr),
 379                                        mei_slots2data(meta_hdr->size),
 380                                        &hdr_size_ext)) {
 381                         dev_err(dev->dev, "extended message size too big %d\n",
 382                                 meta_hdr->size);
 383                         return -EBADMSG;
 384                 }
 385                 if (hdr_size_left < hdr_size_ext) {
 386                         dev_err(dev->dev, "corrupted message header len %d\n",
 387                                 mei_hdr->length);
 388                         return -EBADMSG;
 389                 }
 390                 hdr_size_left -= hdr_size_ext;
 391
 392                 ext_hdr_end = meta_hdr->size + 2;
 393                 for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) {
 394                         dev->rd_msg_hdr[i] = mei_read_hdr(dev);
 395                         dev_dbg(dev->dev, "extended header %d is %08x\n", i,
 396                                 dev->rd_msg_hdr[i]);
 397                         dev->rd_msg_hdr_count++;
 398                         (*slots)--;
 399                 }
 400         }
 401
 402         if (mei_hdr->dma_ring) {
 403                 if (hdr_size_left != sizeof(dev->rd_msg_hdr[ext_hdr_end])) {
 404                         dev_err(dev->dev, "corrupted message header len %d\n",
 405                                 mei_hdr->length);
 406                         return -EBADMSG;
 407                 }
 408
 409                 dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev);
 410                 dev->rd_msg_hdr_count++;
 411                 (*slots)--;
 412                 mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]);
 413         }
 414
 415         /*  HBM message */
 416         if (hdr_is_hbm(mei_hdr)) {
 417                 ret = mei_hbm_dispatch(dev, mei_hdr);
 418                 if (ret) {
 419                         dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
 420                                         ret);
 421                         goto end;
 422                 }
 423                 goto reset_slots;
 424         }
 425
 426         /* find recipient cl */
 427         list_for_each_entry(cl, &dev->file_list, link) {
 428                 if (mei_cl_hbm_equal(cl, mei_hdr)) {
 429                         cl_dbg(dev, cl, "got a message\n");
 430                         break;
 431                 }
 432         }
 433
 434         /* if no recipient cl was found we assume corrupted header */
 435         if (&cl->link == &dev->file_list) {
 436                 /* A message for not connected fixed address clients
 437                  * should be silently discarded
 438                  * On power down client may be force cleaned,
 439                  * silently discard such messages
 440                  */
 441                 if (hdr_is_fixed(mei_hdr) ||
 442                     dev->dev_state == MEI_DEV_POWER_DOWN) {
 443                         mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length);
 444                         ret = 0;
 445                         goto reset_slots;
 446                 }
 447                 dev_err(dev->dev, "no destination client found 0x%08X\n",
 448                                 dev->rd_msg_hdr[0]);
 449                 ret = -EBADMSG;
 450                 goto end;
 451         }
 452
 453         ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list);
 454
 455
 456 reset_slots:
 457         /* reset the number of slots and header */
 458         memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
 459         dev->rd_msg_hdr_count = 0;
 460         *slots = mei_count_full_read_slots(dev);
 461         if (*slots == -EOVERFLOW) {
 462                 /* overflow - reset */
 463                 dev_err(dev->dev, "resetting due to slots overflow.\n");
 464                 /* set the event since message has been read */
 465                 ret = -ERANGE;
 466                 goto end;
 467         }
 468 end:
 469         return ret;
 470 }
 471 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
 472
 473
 474 /**
 475  * mei_irq_write_handler -  dispatch write requests
 476  *  after irq received
 477  *
 478  * @dev: the device structure
 479  * @cmpl_list: An instance of our list structure
 480  *
 481  * Return: 0 on success, <0 on failure.
 482  */
 483 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
 484 {
 485
 486         struct mei_cl *cl;
 487         struct mei_cl_cb *cb, *next;
 488         s32 slots;
 489         int ret;
 490
 491
 492         if (!mei_hbuf_acquire(dev))
 493                 return 0;
 494
 495         slots = mei_hbuf_empty_slots(dev);
 496         if (slots < 0)
 497                 return -EOVERFLOW;
 498
 499         if (slots == 0)
 500                 return -EMSGSIZE;
 501
 502         /* complete all waiting for write CB */
 503         dev_dbg(dev->dev, "complete all waiting for write cb.\n");
 504
 505         list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
 506                 cl = cb->cl;
 507
 508                 cl->status = 0;
 509                 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
 510                 cl->writing_state = MEI_WRITE_COMPLETE;
 511                 list_move_tail(&cb->list, cmpl_list);
 512         }
 513
 514         /* complete control write list CB */
 515         dev_dbg(dev->dev, "complete control write list cb.\n");
 516         list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
 517                 cl = cb->cl;
 518                 switch (cb->fop_type) {
 519                 case MEI_FOP_DISCONNECT:
 520                         /* send disconnect message */
 521                         ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
 522                         if (ret)
 523                                 return ret;
 524
 525                         break;
 526                 case MEI_FOP_READ:
 527                         /* send flow control message */
 528                         ret = mei_cl_irq_read(cl, cb, cmpl_list);
 529                         if (ret)
 530                                 return ret;
 531
 532                         break;
 533                 case MEI_FOP_CONNECT:
 534                         /* connect message */
 535                         ret = mei_cl_irq_connect(cl, cb, cmpl_list);
 536                         if (ret)
 537                                 return ret;
 538
 539                         break;
 540                 case MEI_FOP_DISCONNECT_RSP:
 541                         /* send disconnect resp */
 542                         ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
 543                         if (ret)
 544                                 return ret;
 545                         break;
 546
 547                 case MEI_FOP_NOTIFY_START:
 548                 case MEI_FOP_NOTIFY_STOP:
 549                         ret = mei_cl_irq_notify(cl, cb, cmpl_list);
 550                         if (ret)
 551                                 return ret;
 552                         break;
 553                 case MEI_FOP_DMA_MAP:
 554                         ret = mei_cl_irq_dma_map(cl, cb, cmpl_list);
 555                         if (ret)
 556                                 return ret;
 557                         break;
 558                 case MEI_FOP_DMA_UNMAP:
 559                         ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list);
 560                         if (ret)
 561                                 return ret;
 562                         break;
 563                 default:
 564                         BUG();
 565                 }
 566
 567         }
 568         /* complete  write list CB */
 569         dev_dbg(dev->dev, "complete write list cb.\n");
 570         list_for_each_entry_safe(cb, next, &dev->write_list, list) {
 571                 cl = cb->cl;
 572                 ret = mei_cl_irq_write(cl, cb, cmpl_list);
 573                 if (ret)
 574                         return ret;
 575         }
 576         return 0;
 577 }
 578 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
 579
 580
 581 /**
 582  * mei_connect_timeout  - connect/disconnect timeouts
 583  *
 584  * @cl: host client
 585  */
 586 static void mei_connect_timeout(struct mei_cl *cl)
 587 {
 588         struct mei_device *dev = cl->dev;
 589
 590         if (cl->state == MEI_FILE_CONNECTING) {
 591                 if (dev->hbm_f_dot_supported) {
 592                         cl->state = MEI_FILE_DISCONNECT_REQUIRED;
 593                         wake_up(&cl->wait);
 594                         return;
 595                 }
 596         }
 597         mei_reset(dev);
 598 }
 599
 600 #define MEI_STALL_TIMER_FREQ (2 * HZ)
 601 /**
 602  * mei_schedule_stall_timer - re-arm stall_timer work
 603  *
 604  * Schedule stall timer
 605  *
 606  * @dev: the device structure
 607  */
 608 void mei_schedule_stall_timer(struct mei_device *dev)
 609 {
 610         schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
 611 }
 612
 613 /**
 614  * mei_timer - timer function.
 615  *
 616  * @work: pointer to the work_struct structure
 617  *
 618  */
 619 void mei_timer(struct work_struct *work)
 620 {
 621         struct mei_cl *cl;
 622         struct mei_device *dev = container_of(work,
 623                                         struct mei_device, timer_work.work);
 624         bool reschedule_timer = false;
 625
 626         mutex_lock(&dev->device_lock);
 627
 628         /* Catch interrupt stalls during HBM init handshake */
 629         if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
 630             dev->hbm_state != MEI_HBM_IDLE) {
 631
 632                 if (dev->init_clients_timer) {
 633                         if (--dev->init_clients_timer == 0) {
 634                                 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
 635                                         dev->hbm_state);
 636                                 mei_reset(dev);
 637                                 goto out;
 638                         }
 639                         reschedule_timer = true;
 640                 }
 641         }
 642
 643         if (dev->dev_state != MEI_DEV_ENABLED)
 644                 goto out;
 645
 646         /*** connect/disconnect timeouts ***/
 647         list_for_each_entry(cl, &dev->file_list, link) {
 648                 if (cl->timer_count) {
 649                         if (--cl->timer_count == 0) {
 650                                 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
 651                                 mei_connect_timeout(cl);
 652                                 goto out;
 653                         }
 654                         reschedule_timer = true;
 655                 }
 656         }
 657
 658 out:
 659         if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
 660                 mei_schedule_stall_timer(dev);
 661
 662         mutex_unlock(&dev->device_lock);
 663 }