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  */
  65 static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
  66 {
  67         if (hdr->dma_ring)
  68                 mei_dma_ring_read(dev, NULL, hdr->extension[0]);
  69         /*
  70          * no need to check for size as it is guarantied
  71          * that length fits into rd_msg_buf
  72          */
  73         mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
  74         dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
  75                 MEI_HDR_PRM(hdr));
  76 }
  77
  78 /**
  79  * mei_cl_irq_read_msg - process client message
  80  *
  81  * @cl: reading client
  82  * @mei_hdr: header of mei client message
  83  * @cmpl_list: completion list
  84  *
  85  * Return: always 0
  86  */
  87 static int mei_cl_irq_read_msg(struct mei_cl *cl,
  88                                struct mei_msg_hdr *mei_hdr,
  89                                struct list_head *cmpl_list)
  90 {
  91         struct mei_device *dev = cl->dev;
  92         struct mei_cl_cb *cb;
  93         size_t buf_sz;
  94         u32 length;
  95
  96         cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
  97         if (!cb) {
  98                 if (!mei_cl_is_fixed_address(cl)) {
  99                         cl_err(dev, cl, "pending read cb not found\n");
 100                         goto discard;
 101                 }
 102                 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
 103                 if (!cb)
 104                         goto discard;
 105                 list_add_tail(&cb->list, &cl->rd_pending);
 106         }
 107
 108         if (!mei_cl_is_connected(cl)) {
 109                 cl_dbg(dev, cl, "not connected\n");
 110                 cb->status = -ENODEV;
 111                 goto discard;
 112         }
 113
 114         length = mei_hdr->dma_ring ? mei_hdr->extension[0] : mei_hdr->length;
 115
 116         buf_sz = length + cb->buf_idx;
 117         /* catch for integer overflow */
 118         if (buf_sz < cb->buf_idx) {
 119                 cl_err(dev, cl, "message is too big len %d idx %zu\n",
 120                        length, cb->buf_idx);
 121                 cb->status = -EMSGSIZE;
 122                 goto discard;
 123         }
 124
 125         if (cb->buf.size < buf_sz) {
 126                 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
 127                         cb->buf.size, length, cb->buf_idx);
 128                 cb->status = -EMSGSIZE;
 129                 goto discard;
 130         }
 131
 132         if (mei_hdr->dma_ring)
 133                 mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length);
 134
 135         /*  for DMA read 0 length to generate an interrupt to the device */
 136         mei_read_slots(dev, cb->buf.data + cb->buf_idx, mei_hdr->length);
 137
 138         cb->buf_idx += length;
 139
 140         if (mei_hdr->msg_complete) {
 141                 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
 142                 list_move_tail(&cb->list, cmpl_list);
 143         } else {
 144                 pm_runtime_mark_last_busy(dev->dev);
 145                 pm_request_autosuspend(dev->dev);
 146         }
 147
 148         return 0;
 149
 150 discard:
 151         if (cb)
 152                 list_move_tail(&cb->list, cmpl_list);
 153         mei_irq_discard_msg(dev, mei_hdr);
 154         return 0;
 155 }
 156
 157 /**
 158  * mei_cl_irq_disconnect_rsp - send disconnection response message
 159  *
 160  * @cl: client
 161  * @cb: callback block.
 162  * @cmpl_list: complete list.
 163  *
 164  * Return: 0, OK; otherwise, error.
 165  */
 166 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
 167                                      struct list_head *cmpl_list)
 168 {
 169         struct mei_device *dev = cl->dev;
 170         u32 msg_slots;
 171         int slots;
 172         int ret;
 173
 174         msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
 175         slots = mei_hbuf_empty_slots(dev);
 176         if (slots < 0)
 177                 return -EOVERFLOW;
 178
 179         if ((u32)slots < msg_slots)
 180                 return -EMSGSIZE;
 181
 182         ret = mei_hbm_cl_disconnect_rsp(dev, cl);
 183         list_move_tail(&cb->list, cmpl_list);
 184
 185         return ret;
 186 }
 187
 188 /**
 189  * mei_cl_irq_read - processes client read related operation from the
 190  *      interrupt thread context - request for flow control credits
 191  *
 192  * @cl: client
 193  * @cb: callback block.
 194  * @cmpl_list: complete list.
 195  *
 196  * Return: 0, OK; otherwise, error.
 197  */
 198 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
 199                            struct list_head *cmpl_list)
 200 {
 201         struct mei_device *dev = cl->dev;
 202         u32 msg_slots;
 203         int slots;
 204         int ret;
 205
 206         if (!list_empty(&cl->rd_pending))
 207                 return 0;
 208
 209         msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
 210         slots = mei_hbuf_empty_slots(dev);
 211         if (slots < 0)
 212                 return -EOVERFLOW;
 213
 214         if ((u32)slots < msg_slots)
 215                 return -EMSGSIZE;
 216
 217         ret = mei_hbm_cl_flow_control_req(dev, cl);
 218         if (ret) {
 219                 cl->status = ret;
 220                 cb->buf_idx = 0;
 221                 list_move_tail(&cb->list, cmpl_list);
 222                 return ret;
 223         }
 224
 225         list_move_tail(&cb->list, &cl->rd_pending);
 226
 227         return 0;
 228 }
 229
 230 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
 231 {
 232         return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
 233 }
 234
 235 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
 236 {
 237         return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
 238 }
 239
 240 static inline int hdr_is_valid(u32 msg_hdr)
 241 {
 242         struct mei_msg_hdr *mei_hdr;
 243
 244         mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
 245         if (!msg_hdr || mei_hdr->reserved)
 246                 return -EBADMSG;
 247
 248         if (mei_hdr->dma_ring && mei_hdr->length != MEI_SLOT_SIZE)
 249                 return -EBADMSG;
 250
 251         return 0;
 252 }
 253
 254 /**
 255  * mei_irq_read_handler - bottom half read routine after ISR to
 256  * handle the read processing.
 257  *
 258  * @dev: the device structure
 259  * @cmpl_list: An instance of our list structure
 260  * @slots: slots to read.
 261  *
 262  * Return: 0 on success, <0 on failure.
 263  */
 264 int mei_irq_read_handler(struct mei_device *dev,
 265                          struct list_head *cmpl_list, s32 *slots)
 266 {
 267         struct mei_msg_hdr *mei_hdr;
 268         struct mei_cl *cl;
 269         int ret;
 270
 271         if (!dev->rd_msg_hdr[0]) {
 272                 dev->rd_msg_hdr[0] = mei_read_hdr(dev);
 273                 (*slots)--;
 274                 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
 275
 276                 ret = hdr_is_valid(dev->rd_msg_hdr[0]);
 277                 if (ret) {
 278                         dev_err(dev->dev, "corrupted message header 0x%08X\n",
 279                                 dev->rd_msg_hdr[0]);
 280                         goto end;
 281                 }
 282         }
 283
 284         mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
 285         dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
 286
 287         if (mei_slots2data(*slots) < mei_hdr->length) {
 288                 dev_err(dev->dev, "less data available than length=%08x.\n",
 289                                 *slots);
 290                 /* we can't read the message */
 291                 ret = -ENODATA;
 292                 goto end;
 293         }
 294
 295         if (mei_hdr->dma_ring) {
 296                 dev->rd_msg_hdr[1] = mei_read_hdr(dev);
 297                 (*slots)--;
 298                 mei_hdr->length = 0;
 299         }
 300
 301         /*  HBM message */
 302         if (hdr_is_hbm(mei_hdr)) {
 303                 ret = mei_hbm_dispatch(dev, mei_hdr);
 304                 if (ret) {
 305                         dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
 306                                         ret);
 307                         goto end;
 308                 }
 309                 goto reset_slots;
 310         }
 311
 312         /* find recipient cl */
 313         list_for_each_entry(cl, &dev->file_list, link) {
 314                 if (mei_cl_hbm_equal(cl, mei_hdr)) {
 315                         cl_dbg(dev, cl, "got a message\n");
 316                         break;
 317                 }
 318         }
 319
 320         /* if no recipient cl was found we assume corrupted header */
 321         if (&cl->link == &dev->file_list) {
 322                 /* A message for not connected fixed address clients
 323                  * should be silently discarded
 324                  * On power down client may be force cleaned,
 325                  * silently discard such messages
 326                  */
 327                 if (hdr_is_fixed(mei_hdr) ||
 328                     dev->dev_state == MEI_DEV_POWER_DOWN) {
 329                         mei_irq_discard_msg(dev, mei_hdr);
 330                         ret = 0;
 331                         goto reset_slots;
 332                 }
 333                 dev_err(dev->dev, "no destination client found 0x%08X\n",
 334                                 dev->rd_msg_hdr[0]);
 335                 ret = -EBADMSG;
 336                 goto end;
 337         }
 338
 339         ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
 340
 341
 342 reset_slots:
 343         /* reset the number of slots and header */
 344         memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
 345         *slots = mei_count_full_read_slots(dev);
 346         if (*slots == -EOVERFLOW) {
 347                 /* overflow - reset */
 348                 dev_err(dev->dev, "resetting due to slots overflow.\n");
 349                 /* set the event since message has been read */
 350                 ret = -ERANGE;
 351                 goto end;
 352         }
 353 end:
 354         return ret;
 355 }
 356 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
 357
 358
 359 /**
 360  * mei_irq_write_handler -  dispatch write requests
 361  *  after irq received
 362  *
 363  * @dev: the device structure
 364  * @cmpl_list: An instance of our list structure
 365  *
 366  * Return: 0 on success, <0 on failure.
 367  */
 368 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
 369 {
 370
 371         struct mei_cl *cl;
 372         struct mei_cl_cb *cb, *next;
 373         s32 slots;
 374         int ret;
 375
 376
 377         if (!mei_hbuf_acquire(dev))
 378                 return 0;
 379
 380         slots = mei_hbuf_empty_slots(dev);
 381         if (slots < 0)
 382                 return -EOVERFLOW;
 383
 384         if (slots == 0)
 385                 return -EMSGSIZE;
 386
 387         /* complete all waiting for write CB */
 388         dev_dbg(dev->dev, "complete all waiting for write cb.\n");
 389
 390         list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
 391                 cl = cb->cl;
 392
 393                 cl->status = 0;
 394                 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
 395                 cl->writing_state = MEI_WRITE_COMPLETE;
 396                 list_move_tail(&cb->list, cmpl_list);
 397         }
 398
 399         /* complete control write list CB */
 400         dev_dbg(dev->dev, "complete control write list cb.\n");
 401         list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
 402                 cl = cb->cl;
 403                 switch (cb->fop_type) {
 404                 case MEI_FOP_DISCONNECT:
 405                         /* send disconnect message */
 406                         ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
 407                         if (ret)
 408                                 return ret;
 409
 410                         break;
 411                 case MEI_FOP_READ:
 412                         /* send flow control message */
 413                         ret = mei_cl_irq_read(cl, cb, cmpl_list);
 414                         if (ret)
 415                                 return ret;
 416
 417                         break;
 418                 case MEI_FOP_CONNECT:
 419                         /* connect message */
 420                         ret = mei_cl_irq_connect(cl, cb, cmpl_list);
 421                         if (ret)
 422                                 return ret;
 423
 424                         break;
 425                 case MEI_FOP_DISCONNECT_RSP:
 426                         /* send disconnect resp */
 427                         ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
 428                         if (ret)
 429                                 return ret;
 430                         break;
 431
 432                 case MEI_FOP_NOTIFY_START:
 433                 case MEI_FOP_NOTIFY_STOP:
 434                         ret = mei_cl_irq_notify(cl, cb, cmpl_list);
 435                         if (ret)
 436                                 return ret;
 437                         break;
 438                 default:
 439                         BUG();
 440                 }
 441
 442         }
 443         /* complete  write list CB */
 444         dev_dbg(dev->dev, "complete write list cb.\n");
 445         list_for_each_entry_safe(cb, next, &dev->write_list, list) {
 446                 cl = cb->cl;
 447                 ret = mei_cl_irq_write(cl, cb, cmpl_list);
 448                 if (ret)
 449                         return ret;
 450         }
 451         return 0;
 452 }
 453 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
 454
 455
 456 /**
 457  * mei_connect_timeout  - connect/disconnect timeouts
 458  *
 459  * @cl: host client
 460  */
 461 static void mei_connect_timeout(struct mei_cl *cl)
 462 {
 463         struct mei_device *dev = cl->dev;
 464
 465         if (cl->state == MEI_FILE_CONNECTING) {
 466                 if (dev->hbm_f_dot_supported) {
 467                         cl->state = MEI_FILE_DISCONNECT_REQUIRED;
 468                         wake_up(&cl->wait);
 469                         return;
 470                 }
 471         }
 472         mei_reset(dev);
 473 }
 474
 475 #define MEI_STALL_TIMER_FREQ (2 * HZ)
 476 /**
 477  * mei_schedule_stall_timer - re-arm stall_timer work
 478  *
 479  * Schedule stall timer
 480  *
 481  * @dev: the device structure
 482  */
 483 void mei_schedule_stall_timer(struct mei_device *dev)
 484 {
 485         schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
 486 }
 487
 488 /**
 489  * mei_timer - timer function.
 490  *
 491  * @work: pointer to the work_struct structure
 492  *
 493  */
 494 void mei_timer(struct work_struct *work)
 495 {
 496         struct mei_cl *cl;
 497         struct mei_device *dev = container_of(work,
 498                                         struct mei_device, timer_work.work);
 499         bool reschedule_timer = false;
 500
 501         mutex_lock(&dev->device_lock);
 502
 503         /* Catch interrupt stalls during HBM init handshake */
 504         if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
 505             dev->hbm_state != MEI_HBM_IDLE) {
 506
 507                 if (dev->init_clients_timer) {
 508                         if (--dev->init_clients_timer == 0) {
 509                                 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
 510                                         dev->hbm_state);
 511                                 mei_reset(dev);
 512                                 goto out;
 513                         }
 514                         reschedule_timer = true;
 515                 }
 516         }
 517
 518         if (dev->dev_state != MEI_DEV_ENABLED)
 519                 goto out;
 520
 521         /*** connect/disconnect timeouts ***/
 522         list_for_each_entry(cl, &dev->file_list, link) {
 523                 if (cl->timer_count) {
 524                         if (--cl->timer_count == 0) {
 525                                 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
 526                                 mei_connect_timeout(cl);
 527                                 goto out;
 528                         }
 529                         reschedule_timer = true;
 530                 }
 531         }
 532
 533 out:
 534         if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
 535                 mei_schedule_stall_timer(dev);
 536
 537         mutex_unlock(&dev->device_lock);
 538 }