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  * @compl_list: list of completed cbs
  39  */
  40 void mei_irq_compl_handler(struct mei_device *dev, struct mei_cl_cb *compl_list)
  41 {
  42         struct mei_cl_cb *cb, *next;
  43         struct mei_cl *cl;
  44
  45         list_for_each_entry_safe(cb, next, &compl_list->list, list) {
  46                 cl = cb->cl;
  47                 list_del_init(&cb->list);
  48
  49                 dev_dbg(dev->dev, "completing call back.\n");
  50                 if (cl == &dev->iamthif_cl)
  51                         mei_amthif_complete(cl, cb);
  52                 else
  53                         mei_cl_complete(cl, cb);
  54         }
  55 }
  56 EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
  57
  58 /**
  59  * mei_cl_hbm_equal - check if hbm is addressed to the client
  60  *
  61  * @cl: host client
  62  * @mei_hdr: header of mei client message
  63  *
  64  * Return: true if matches, false otherwise
  65  */
  66 static inline int mei_cl_hbm_equal(struct mei_cl *cl,
  67                         struct mei_msg_hdr *mei_hdr)
  68 {
  69         return  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
  70                 mei_cl_me_id(cl) == mei_hdr->me_addr;
  71 }
  72
  73 /**
  74  * mei_irq_discard_msg  - discard received message
  75  *
  76  * @dev: mei device
  77  * @hdr: message header
  78  */
  79 void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
  80 {
  81         /*
  82          * no need to check for size as it is guarantied
  83          * that length fits into rd_msg_buf
  84          */
  85         mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
  86         dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
  87                 MEI_HDR_PRM(hdr));
  88 }
  89
  90 /**
  91  * mei_cl_irq_read_msg - process client message
  92  *
  93  * @cl: reading client
  94  * @mei_hdr: header of mei client message
  95  * @complete_list: completion list
  96  *
  97  * Return: always 0
  98  */
  99 int mei_cl_irq_read_msg(struct mei_cl *cl,
 100                        struct mei_msg_hdr *mei_hdr,
 101                        struct mei_cl_cb *complete_list)
 102 {
 103         struct mei_device *dev = cl->dev;
 104         struct mei_cl_cb *cb;
 105         size_t buf_sz;
 106
 107         cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
 108         if (!cb) {
 109                 if (!mei_cl_is_fixed_address(cl)) {
 110                         cl_err(dev, cl, "pending read cb not found\n");
 111                         goto discard;
 112                 }
 113                 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
 114                 if (!cb)
 115                         goto discard;
 116                 list_add_tail(&cb->list, &cl->rd_pending);
 117         }
 118
 119         if (!mei_cl_is_connected(cl)) {
 120                 cl_dbg(dev, cl, "not connected\n");
 121                 cb->status = -ENODEV;
 122                 goto discard;
 123         }
 124
 125         buf_sz = mei_hdr->length + cb->buf_idx;
 126         /* catch for integer overflow */
 127         if (buf_sz < cb->buf_idx) {
 128                 cl_err(dev, cl, "message is too big len %d idx %zu\n",
 129                        mei_hdr->length, cb->buf_idx);
 130                 cb->status = -EMSGSIZE;
 131                 goto discard;
 132         }
 133
 134         if (cb->buf.size < buf_sz) {
 135                 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
 136                         cb->buf.size, mei_hdr->length, cb->buf_idx);
 137                 cb->status = -EMSGSIZE;
 138                 goto discard;
 139         }
 140
 141         mei_read_slots(dev, cb->buf.data + cb->buf_idx, mei_hdr->length);
 142
 143         cb->buf_idx += mei_hdr->length;
 144
 145         if (mei_hdr->msg_complete) {
 146                 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
 147                 list_move_tail(&cb->list, &complete_list->list);
 148         } else {
 149                 pm_runtime_mark_last_busy(dev->dev);
 150                 pm_request_autosuspend(dev->dev);
 151         }
 152
 153         return 0;
 154
 155 discard:
 156         if (cb)
 157                 list_move_tail(&cb->list, &complete_list->list);
 158         mei_irq_discard_msg(dev, mei_hdr);
 159         return 0;
 160 }
 161
 162 /**
 163  * mei_cl_irq_disconnect_rsp - send disconnection response message
 164  *
 165  * @cl: client
 166  * @cb: callback block.
 167  * @cmpl_list: complete list.
 168  *
 169  * Return: 0, OK; otherwise, error.
 170  */
 171 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
 172                                      struct mei_cl_cb *cmpl_list)
 173 {
 174         struct mei_device *dev = cl->dev;
 175         u32 msg_slots;
 176         int slots;
 177         int ret;
 178
 179         slots = mei_hbuf_empty_slots(dev);
 180         msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_response));
 181
 182         if (slots < msg_slots)
 183                 return -EMSGSIZE;
 184
 185         ret = mei_hbm_cl_disconnect_rsp(dev, cl);
 186         list_move_tail(&cb->list, &cmpl_list->list);
 187
 188         return ret;
 189 }
 190
 191 /**
 192  * mei_cl_irq_read - processes client read related operation from the
 193  *      interrupt thread context - request for flow control credits
 194  *
 195  * @cl: client
 196  * @cb: callback block.
 197  * @cmpl_list: complete list.
 198  *
 199  * Return: 0, OK; otherwise, error.
 200  */
 201 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
 202                            struct mei_cl_cb *cmpl_list)
 203 {
 204         struct mei_device *dev = cl->dev;
 205         u32 msg_slots;
 206         int slots;
 207         int ret;
 208
 209         if (!list_empty(&cl->rd_pending))
 210                 return 0;
 211
 212         msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
 213         slots = mei_hbuf_empty_slots(dev);
 214
 215         if (slots < msg_slots)
 216                 return -EMSGSIZE;
 217
 218         ret = mei_hbm_cl_flow_control_req(dev, cl);
 219         if (ret) {
 220                 cl->status = ret;
 221                 cb->buf_idx = 0;
 222                 list_move_tail(&cb->list, &cmpl_list->list);
 223                 return ret;
 224         }
 225
 226         list_move_tail(&cb->list, &cl->rd_pending);
 227
 228         return 0;
 229 }
 230
 231 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
 232 {
 233         return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
 234 }
 235
 236 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
 237 {
 238         return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
 239 }
 240
 241 /**
 242  * mei_irq_read_handler - bottom half read routine after ISR to
 243  * handle the read processing.
 244  *
 245  * @dev: the device structure
 246  * @cmpl_list: An instance of our list structure
 247  * @slots: slots to read.
 248  *
 249  * Return: 0 on success, <0 on failure.
 250  */
 251 int mei_irq_read_handler(struct mei_device *dev,
 252                 struct mei_cl_cb *cmpl_list, s32 *slots)
 253 {
 254         struct mei_msg_hdr *mei_hdr;
 255         struct mei_cl *cl;
 256         int ret;
 257
 258         if (!dev->rd_msg_hdr) {
 259                 dev->rd_msg_hdr = mei_read_hdr(dev);
 260                 (*slots)--;
 261                 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
 262         }
 263         mei_hdr = (struct mei_msg_hdr *) &dev->rd_msg_hdr;
 264         dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
 265
 266         if (mei_hdr->reserved || !dev->rd_msg_hdr) {
 267                 dev_err(dev->dev, "corrupted message header 0x%08X\n",
 268                                 dev->rd_msg_hdr);
 269                 ret = -EBADMSG;
 270                 goto end;
 271         }
 272
 273         if (mei_slots2data(*slots) < mei_hdr->length) {
 274                 dev_err(dev->dev, "less data available than length=%08x.\n",
 275                                 *slots);
 276                 /* we can't read the message */
 277                 ret = -ENODATA;
 278                 goto end;
 279         }
 280
 281         /*  HBM message */
 282         if (hdr_is_hbm(mei_hdr)) {
 283                 ret = mei_hbm_dispatch(dev, mei_hdr);
 284                 if (ret) {
 285                         dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
 286                                         ret);
 287                         goto end;
 288                 }
 289                 goto reset_slots;
 290         }
 291
 292         /* find recipient cl */
 293         list_for_each_entry(cl, &dev->file_list, link) {
 294                 if (mei_cl_hbm_equal(cl, mei_hdr)) {
 295                         cl_dbg(dev, cl, "got a message\n");
 296                         break;
 297                 }
 298         }
 299
 300         /* if no recipient cl was found we assume corrupted header */
 301         if (&cl->link == &dev->file_list) {
 302                 /* A message for not connected fixed address clients
 303                  * should be silently discarded
 304                  */
 305                 if (hdr_is_fixed(mei_hdr)) {
 306                         mei_irq_discard_msg(dev, mei_hdr);
 307                         ret = 0;
 308                         goto reset_slots;
 309                 }
 310                 dev_err(dev->dev, "no destination client found 0x%08X\n",
 311                                 dev->rd_msg_hdr);
 312                 ret = -EBADMSG;
 313                 goto end;
 314         }
 315
 316         if (cl == &dev->iamthif_cl) {
 317                 ret = mei_amthif_irq_read_msg(cl, mei_hdr, cmpl_list);
 318         } else {
 319                 ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
 320         }
 321
 322
 323 reset_slots:
 324         /* reset the number of slots and header */
 325         *slots = mei_count_full_read_slots(dev);
 326         dev->rd_msg_hdr = 0;
 327
 328         if (*slots == -EOVERFLOW) {
 329                 /* overflow - reset */
 330                 dev_err(dev->dev, "resetting due to slots overflow.\n");
 331                 /* set the event since message has been read */
 332                 ret = -ERANGE;
 333                 goto end;
 334         }
 335 end:
 336         return ret;
 337 }
 338 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
 339
 340
 341 /**
 342  * mei_irq_write_handler -  dispatch write requests
 343  *  after irq received
 344  *
 345  * @dev: the device structure
 346  * @cmpl_list: An instance of our list structure
 347  *
 348  * Return: 0 on success, <0 on failure.
 349  */
 350 int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list)
 351 {
 352
 353         struct mei_cl *cl;
 354         struct mei_cl_cb *cb, *next;
 355         struct mei_cl_cb *list;
 356         s32 slots;
 357         int ret;
 358
 359
 360         if (!mei_hbuf_acquire(dev))
 361                 return 0;
 362
 363         slots = mei_hbuf_empty_slots(dev);
 364         if (slots <= 0)
 365                 return -EMSGSIZE;
 366
 367         /* complete all waiting for write CB */
 368         dev_dbg(dev->dev, "complete all waiting for write cb.\n");
 369
 370         list = &dev->write_waiting_list;
 371         list_for_each_entry_safe(cb, next, &list->list, list) {
 372                 cl = cb->cl;
 373
 374                 cl->status = 0;
 375                 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
 376                 cl->writing_state = MEI_WRITE_COMPLETE;
 377                 list_move_tail(&cb->list, &cmpl_list->list);
 378         }
 379
 380         /* complete control write list CB */
 381         dev_dbg(dev->dev, "complete control write list cb.\n");
 382         list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list.list, list) {
 383                 cl = cb->cl;
 384                 switch (cb->fop_type) {
 385                 case MEI_FOP_DISCONNECT:
 386                         /* send disconnect message */
 387                         ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
 388                         if (ret)
 389                                 return ret;
 390
 391                         break;
 392                 case MEI_FOP_READ:
 393                         /* send flow control message */
 394                         ret = mei_cl_irq_read(cl, cb, cmpl_list);
 395                         if (ret)
 396                                 return ret;
 397
 398                         break;
 399                 case MEI_FOP_CONNECT:
 400                         /* connect message */
 401                         ret = mei_cl_irq_connect(cl, cb, cmpl_list);
 402                         if (ret)
 403                                 return ret;
 404
 405                         break;
 406                 case MEI_FOP_DISCONNECT_RSP:
 407                         /* send disconnect resp */
 408                         ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
 409                         if (ret)
 410                                 return ret;
 411                         break;
 412
 413                 case MEI_FOP_NOTIFY_START:
 414                 case MEI_FOP_NOTIFY_STOP:
 415                         ret = mei_cl_irq_notify(cl, cb, cmpl_list);
 416                         if (ret)
 417                                 return ret;
 418                         break;
 419                 default:
 420                         BUG();
 421                 }
 422
 423         }
 424         /* complete  write list CB */
 425         dev_dbg(dev->dev, "complete write list cb.\n");
 426         list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
 427                 cl = cb->cl;
 428                 if (cl == &dev->iamthif_cl)
 429                         ret = mei_amthif_irq_write(cl, cb, cmpl_list);
 430                 else
 431                         ret = mei_cl_irq_write(cl, cb, cmpl_list);
 432                 if (ret)
 433                         return ret;
 434         }
 435         return 0;
 436 }
 437 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
 438
 439
 440 /**
 441  * mei_connect_timeout  - connect/disconnect timeouts
 442  *
 443  * @cl: host client
 444  */
 445 static void mei_connect_timeout(struct mei_cl *cl)
 446 {
 447         struct mei_device *dev = cl->dev;
 448
 449         if (cl->state == MEI_FILE_CONNECTING) {
 450                 if (dev->hbm_f_dot_supported) {
 451                         cl->state = MEI_FILE_DISCONNECT_REQUIRED;
 452                         wake_up(&cl->wait);
 453                         return;
 454                 }
 455         }
 456         mei_reset(dev);
 457 }
 458
 459 #define MEI_STALL_TIMER_FREQ (2 * HZ)
 460 /**
 461  * mei_schedule_stall_timer - re-arm stall_timer work
 462  *
 463  * Schedule stall timer
 464  *
 465  * @dev: the device structure
 466  */
 467 void mei_schedule_stall_timer(struct mei_device *dev)
 468 {
 469         schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
 470 }
 471
 472 /**
 473  * mei_timer - timer function.
 474  *
 475  * @work: pointer to the work_struct structure
 476  *
 477  */
 478 void mei_timer(struct work_struct *work)
 479 {
 480         struct mei_cl *cl;
 481         struct mei_device *dev = container_of(work,
 482                                         struct mei_device, timer_work.work);
 483         bool reschedule_timer = false;
 484
 485         mutex_lock(&dev->device_lock);
 486
 487         /* Catch interrupt stalls during HBM init handshake */
 488         if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
 489             dev->hbm_state != MEI_HBM_IDLE) {
 490
 491                 if (dev->init_clients_timer) {
 492                         if (--dev->init_clients_timer == 0) {
 493                                 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
 494                                         dev->hbm_state);
 495                                 mei_reset(dev);
 496                                 goto out;
 497                         }
 498                         reschedule_timer = true;
 499                 }
 500         }
 501
 502         if (dev->dev_state != MEI_DEV_ENABLED)
 503                 goto out;
 504
 505         /*** connect/disconnect timeouts ***/
 506         list_for_each_entry(cl, &dev->file_list, link) {
 507                 if (cl->timer_count) {
 508                         if (--cl->timer_count == 0) {
 509                                 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
 510                                 mei_connect_timeout(cl);
 511                                 goto out;
 512                         }
 513                         reschedule_timer = true;
 514                 }
 515         }
 516
 517         if (!mei_cl_is_connected(&dev->iamthif_cl))
 518                 goto out;
 519
 520         if (dev->iamthif_stall_timer) {
 521                 if (--dev->iamthif_stall_timer == 0) {
 522                         dev_err(dev->dev, "timer: amthif  hanged.\n");
 523                         mei_reset(dev);
 524
 525                         mei_amthif_run_next_cmd(dev);
 526                         goto out;
 527                 }
 528                 reschedule_timer = true;
 529         }
 530
 531 out:
 532         if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
 533                 mei_schedule_stall_timer(dev);
 534
 535         mutex_unlock(&dev->device_lock);
 536 }