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