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  * @cmpl_list: list of completed cbs
  39  */
  40 void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list)
  41 {
  42         struct mei_cl_cb *cb, *next;
  43         struct mei_cl *cl;
  44
  45         list_for_each_entry_safe(cb, next, cmpl_list, list) {
  46                 cl = cb->cl;
  47                 list_del_init(&cb->list);
  48
  49                 dev_dbg(dev->dev, "completing call back.\n");
  50                 mei_cl_complete(cl, cb);
  51         }
  52 }
  53 EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
  54
  55 /**
  56  * mei_cl_hbm_equal - check if hbm is addressed to the client
  57  *
  58  * @cl: host client
  59  * @mei_hdr: header of mei client message
  60  *
  61  * Return: true if matches, false otherwise
  62  */
  63 static inline int mei_cl_hbm_equal(struct mei_cl *cl,
  64                         struct mei_msg_hdr *mei_hdr)
  65 {
  66         return  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
  67                 mei_cl_me_id(cl) == mei_hdr->me_addr;
  68 }
  69
  70 /**
  71  * mei_irq_discard_msg  - discard received message
  72  *
  73  * @dev: mei device
  74  * @hdr: message header
  75  */
  76 static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
  77 {
  78         /*
  79          * no need to check for size as it is guarantied
  80          * that length fits into rd_msg_buf
  81          */
  82         mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
  83         dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
  84                 MEI_HDR_PRM(hdr));
  85 }
  86
  87 /**
  88  * mei_cl_irq_read_msg - process client message
  89  *
  90  * @cl: reading client
  91  * @mei_hdr: header of mei client message
  92  * @cmpl_list: completion list
  93  *
  94  * Return: always 0
  95  */
  96 static int mei_cl_irq_read_msg(struct mei_cl *cl,
  97                                struct mei_msg_hdr *mei_hdr,
  98                                struct list_head *cmpl_list)
  99 {
 100         struct mei_device *dev = cl->dev;
 101         struct mei_cl_cb *cb;
 102         size_t buf_sz;
 103
 104         cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
 105         if (!cb) {
 106                 if (!mei_cl_is_fixed_address(cl)) {
 107                         cl_err(dev, cl, "pending read cb not found\n");
 108                         goto discard;
 109                 }
 110                 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
 111                 if (!cb)
 112                         goto discard;
 113                 list_add_tail(&cb->list, &cl->rd_pending);
 114         }
 115
 116         if (!mei_cl_is_connected(cl)) {
 117                 cl_dbg(dev, cl, "not connected\n");
 118                 cb->status = -ENODEV;
 119                 goto discard;
 120         }
 121
 122         buf_sz = mei_hdr->length + cb->buf_idx;
 123         /* catch for integer overflow */
 124         if (buf_sz < cb->buf_idx) {
 125                 cl_err(dev, cl, "message is too big len %d idx %zu\n",
 126                        mei_hdr->length, cb->buf_idx);
 127                 cb->status = -EMSGSIZE;
 128                 goto discard;
 129         }
 130
 131         if (cb->buf.size < buf_sz) {
 132                 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
 133                         cb->buf.size, mei_hdr->length, cb->buf_idx);
 134                 cb->status = -EMSGSIZE;
 135                 goto discard;
 136         }
 137
 138         mei_read_slots(dev, cb->buf.data + cb->buf_idx, mei_hdr->length);
 139
 140         cb->buf_idx += mei_hdr->length;
 141
 142         if (mei_hdr->msg_complete) {
 143                 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
 144                 list_move_tail(&cb->list, cmpl_list);
 145         } else {
 146                 pm_runtime_mark_last_busy(dev->dev);
 147                 pm_request_autosuspend(dev->dev);
 148         }
 149
 150         return 0;
 151
 152 discard:
 153         if (cb)
 154                 list_move_tail(&cb->list, cmpl_list);
 155         mei_irq_discard_msg(dev, mei_hdr);
 156         return 0;
 157 }
 158
 159 /**
 160  * mei_cl_irq_disconnect_rsp - send disconnection response message
 161  *
 162  * @cl: client
 163  * @cb: callback block.
 164  * @cmpl_list: complete list.
 165  *
 166  * Return: 0, OK; otherwise, error.
 167  */
 168 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
 169                                      struct list_head *cmpl_list)
 170 {
 171         struct mei_device *dev = cl->dev;
 172         u32 msg_slots;
 173         int slots;
 174         int ret;
 175
 176         slots = mei_hbuf_empty_slots(dev);
 177         msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_response));
 178
 179         if (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_data2slots(sizeof(struct hbm_flow_control));
 210         slots = mei_hbuf_empty_slots(dev);
 211
 212         if (slots < msg_slots)
 213                 return -EMSGSIZE;
 214
 215         ret = mei_hbm_cl_flow_control_req(dev, cl);
 216         if (ret) {
 217                 cl->status = ret;
 218                 cb->buf_idx = 0;
 219                 list_move_tail(&cb->list, cmpl_list);
 220                 return ret;
 221         }
 222
 223         list_move_tail(&cb->list, &cl->rd_pending);
 224
 225         return 0;
 226 }
 227
 228 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
 229 {
 230         return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
 231 }
 232
 233 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
 234 {
 235         return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
 236 }
 237
 238 static inline int hdr_is_valid(u32 msg_hdr)
 239 {
 240         struct mei_msg_hdr *mei_hdr;
 241
 242         mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
 243         if (!msg_hdr || mei_hdr->reserved)
 244                 return -EBADMSG;
 245
 246         return 0;
 247 }
 248
 249 /**
 250  * mei_irq_read_handler - bottom half read routine after ISR to
 251  * handle the read processing.
 252  *
 253  * @dev: the device structure
 254  * @cmpl_list: An instance of our list structure
 255  * @slots: slots to read.
 256  *
 257  * Return: 0 on success, <0 on failure.
 258  */
 259 int mei_irq_read_handler(struct mei_device *dev,
 260                          struct list_head *cmpl_list, s32 *slots)
 261 {
 262         struct mei_msg_hdr *mei_hdr;
 263         struct mei_cl *cl;
 264         int ret;
 265
 266         if (!dev->rd_msg_hdr) {
 267                 dev->rd_msg_hdr = mei_read_hdr(dev);
 268                 (*slots)--;
 269                 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
 270
 271                 ret = hdr_is_valid(dev->rd_msg_hdr);
 272                 if (ret) {
 273                         dev_err(dev->dev, "corrupted message header 0x%08X\n",
 274                                 dev->rd_msg_hdr);
 275                         goto end;
 276                 }
 277         }
 278
 279         mei_hdr = (struct mei_msg_hdr *)&dev->rd_msg_hdr;
 280         dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
 281
 282         if (mei_slots2data(*slots) < mei_hdr->length) {
 283                 dev_err(dev->dev, "less data available than length=%08x.\n",
 284                                 *slots);
 285                 /* we can't read the message */
 286                 ret = -ENODATA;
 287                 goto end;
 288         }
 289
 290         /*  HBM message */
 291         if (hdr_is_hbm(mei_hdr)) {
 292                 ret = mei_hbm_dispatch(dev, mei_hdr);
 293                 if (ret) {
 294                         dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
 295                                         ret);
 296                         goto end;
 297                 }
 298                 goto reset_slots;
 299         }
 300
 301         /* find recipient cl */
 302         list_for_each_entry(cl, &dev->file_list, link) {
 303                 if (mei_cl_hbm_equal(cl, mei_hdr)) {
 304                         cl_dbg(dev, cl, "got a message\n");
 305                         break;
 306                 }
 307         }
 308
 309         /* if no recipient cl was found we assume corrupted header */
 310         if (&cl->link == &dev->file_list) {
 311                 /* A message for not connected fixed address clients
 312                  * should be silently discarded
 313                  */
 314                 if (hdr_is_fixed(mei_hdr)) {
 315                         mei_irq_discard_msg(dev, mei_hdr);
 316                         ret = 0;
 317                         goto reset_slots;
 318                 }
 319                 dev_err(dev->dev, "no destination client found 0x%08X\n",
 320                                 dev->rd_msg_hdr);
 321                 ret = -EBADMSG;
 322                 goto end;
 323         }
 324
 325         ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
 326
 327
 328 reset_slots:
 329         /* reset the number of slots and header */
 330         *slots = mei_count_full_read_slots(dev);
 331         dev->rd_msg_hdr = 0;
 332
 333         if (*slots == -EOVERFLOW) {
 334                 /* overflow - reset */
 335                 dev_err(dev->dev, "resetting due to slots overflow.\n");
 336                 /* set the event since message has been read */
 337                 ret = -ERANGE;
 338                 goto end;
 339         }
 340 end:
 341         return ret;
 342 }
 343 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
 344
 345
 346 /**
 347  * mei_irq_write_handler -  dispatch write requests
 348  *  after irq received
 349  *
 350  * @dev: the device structure
 351  * @cmpl_list: An instance of our list structure
 352  *
 353  * Return: 0 on success, <0 on failure.
 354  */
 355 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
 356 {
 357
 358         struct mei_cl *cl;
 359         struct mei_cl_cb *cb, *next;
 360         s32 slots;
 361         int ret;
 362
 363
 364         if (!mei_hbuf_acquire(dev))
 365                 return 0;
 366
 367         slots = mei_hbuf_empty_slots(dev);
 368         if (slots <= 0)
 369                 return -EMSGSIZE;
 370
 371         /* complete all waiting for write CB */
 372         dev_dbg(dev->dev, "complete all waiting for write cb.\n");
 373
 374         list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
 375                 cl = cb->cl;
 376
 377                 cl->status = 0;
 378                 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
 379                 cl->writing_state = MEI_WRITE_COMPLETE;
 380                 list_move_tail(&cb->list, cmpl_list);
 381         }
 382
 383         /* complete control write list CB */
 384         dev_dbg(dev->dev, "complete control write list cb.\n");
 385         list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
 386                 cl = cb->cl;
 387                 switch (cb->fop_type) {
 388                 case MEI_FOP_DISCONNECT:
 389                         /* send disconnect message */
 390                         ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
 391                         if (ret)
 392                                 return ret;
 393
 394                         break;
 395                 case MEI_FOP_READ:
 396                         /* send flow control message */
 397                         ret = mei_cl_irq_read(cl, cb, cmpl_list);
 398                         if (ret)
 399                                 return ret;
 400
 401                         break;
 402                 case MEI_FOP_CONNECT:
 403                         /* connect message */
 404                         ret = mei_cl_irq_connect(cl, cb, cmpl_list);
 405                         if (ret)
 406                                 return ret;
 407
 408                         break;
 409                 case MEI_FOP_DISCONNECT_RSP:
 410                         /* send disconnect resp */
 411                         ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
 412                         if (ret)
 413                                 return ret;
 414                         break;
 415
 416                 case MEI_FOP_NOTIFY_START:
 417                 case MEI_FOP_NOTIFY_STOP:
 418                         ret = mei_cl_irq_notify(cl, cb, cmpl_list);
 419                         if (ret)
 420                                 return ret;
 421                         break;
 422                 default:
 423                         BUG();
 424                 }
 425
 426         }
 427         /* complete  write list CB */
 428         dev_dbg(dev->dev, "complete write list cb.\n");
 429         list_for_each_entry_safe(cb, next, &dev->write_list, list) {
 430                 cl = cb->cl;
 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 out:
 518         if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
 519                 mei_schedule_stall_timer(dev);
 520
 521         mutex_unlock(&dev->device_lock);
 522 }