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(dev, 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         unsigned char *buffer = NULL;
 106
 107         cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
 108         if (!cb) {
 109                 cl_err(dev, cl, "pending read cb not found\n");
 110                 goto out;
 111         }
 112
 113         if (!mei_cl_is_connected(cl)) {
 114                 cl_dbg(dev, cl, "not connected\n");
 115                 cb->status = -ENODEV;
 116                 goto out;
 117         }
 118
 119         if (cb->buf.size == 0 || cb->buf.data == NULL) {
 120                 cl_err(dev, cl, "response buffer is not allocated.\n");
 121                 list_move_tail(&cb->list, &complete_list->list);
 122                 cb->status = -ENOMEM;
 123                 goto out;
 124         }
 125
 126         if (cb->buf.size < mei_hdr->length + cb->buf_idx) {
 127                 cl_dbg(dev, cl, "message overflow. size %d len %d idx %ld\n",
 128                         cb->buf.size, mei_hdr->length, cb->buf_idx);
 129                 buffer = krealloc(cb->buf.data, mei_hdr->length + cb->buf_idx,
 130                                   GFP_KERNEL);
 131
 132                 if (!buffer) {
 133                         cb->status = -ENOMEM;
 134                         list_move_tail(&cb->list, &complete_list->list);
 135                         goto out;
 136                 }
 137                 cb->buf.data = buffer;
 138                 cb->buf.size = mei_hdr->length + cb->buf_idx;
 139         }
 140
 141         buffer = cb->buf.data + cb->buf_idx;
 142         mei_read_slots(dev, buffer, mei_hdr->length);
 143
 144         cb->buf_idx += mei_hdr->length;
 145
 146         if (mei_hdr->msg_complete) {
 147                 cb->read_time = jiffies;
 148                 cl_dbg(dev, cl, "completed read length = %lu\n", cb->buf_idx);
 149                 list_move_tail(&cb->list, &complete_list->list);
 150         } else {
 151                 pm_runtime_mark_last_busy(dev->dev);
 152                 pm_request_autosuspend(dev->dev);
 153         }
 154
 155 out:
 156         if (!buffer)
 157                 mei_irq_discard_msg(dev, mei_hdr);
 158
 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         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->list);
 220                 return ret;
 221         }
 222
 223         pm_runtime_mark_last_busy(dev->dev);
 224         pm_request_autosuspend(dev->dev);
 225
 226         list_move_tail(&cb->list, &cl->rd_pending);
 227
 228         return 0;
 229 }
 230
 231 /**
 232  * mei_irq_read_handler - bottom half read routine after ISR to
 233  * handle the read processing.
 234  *
 235  * @dev: the device structure
 236  * @cmpl_list: An instance of our list structure
 237  * @slots: slots to read.
 238  *
 239  * Return: 0 on success, <0 on failure.
 240  */
 241 int mei_irq_read_handler(struct mei_device *dev,
 242                 struct mei_cl_cb *cmpl_list, s32 *slots)
 243 {
 244         struct mei_msg_hdr *mei_hdr;
 245         struct mei_cl *cl;
 246         int ret;
 247
 248         if (!dev->rd_msg_hdr) {
 249                 dev->rd_msg_hdr = mei_read_hdr(dev);
 250                 (*slots)--;
 251                 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
 252         }
 253         mei_hdr = (struct mei_msg_hdr *) &dev->rd_msg_hdr;
 254         dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
 255
 256         if (mei_hdr->reserved || !dev->rd_msg_hdr) {
 257                 dev_err(dev->dev, "corrupted message header 0x%08X\n",
 258                                 dev->rd_msg_hdr);
 259                 ret = -EBADMSG;
 260                 goto end;
 261         }
 262
 263         if (mei_slots2data(*slots) < mei_hdr->length) {
 264                 dev_err(dev->dev, "less data available than length=%08x.\n",
 265                                 *slots);
 266                 /* we can't read the message */
 267                 ret = -ENODATA;
 268                 goto end;
 269         }
 270
 271         /*  HBM message */
 272         if (mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0) {
 273                 ret = mei_hbm_dispatch(dev, mei_hdr);
 274                 if (ret) {
 275                         dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
 276                                         ret);
 277                         goto end;
 278                 }
 279                 goto reset_slots;
 280         }
 281
 282         /* find recipient cl */
 283         list_for_each_entry(cl, &dev->file_list, link) {
 284                 if (mei_cl_hbm_equal(cl, mei_hdr)) {
 285                         cl_dbg(dev, cl, "got a message\n");
 286                         break;
 287                 }
 288         }
 289
 290         /* if no recipient cl was found we assume corrupted header */
 291         if (&cl->link == &dev->file_list) {
 292                 dev_err(dev->dev, "no destination client found 0x%08X\n",
 293                                 dev->rd_msg_hdr);
 294                 ret = -EBADMSG;
 295                 goto end;
 296         }
 297
 298         if (cl == &dev->iamthif_cl) {
 299                 ret = mei_amthif_irq_read_msg(cl, mei_hdr, cmpl_list);
 300         } else {
 301                 ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
 302         }
 303
 304
 305 reset_slots:
 306         /* reset the number of slots and header */
 307         *slots = mei_count_full_read_slots(dev);
 308         dev->rd_msg_hdr = 0;
 309
 310         if (*slots == -EOVERFLOW) {
 311                 /* overflow - reset */
 312                 dev_err(dev->dev, "resetting due to slots overflow.\n");
 313                 /* set the event since message has been read */
 314                 ret = -ERANGE;
 315                 goto end;
 316         }
 317 end:
 318         return ret;
 319 }
 320 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
 321
 322
 323 /**
 324  * mei_irq_write_handler -  dispatch write requests
 325  *  after irq received
 326  *
 327  * @dev: the device structure
 328  * @cmpl_list: An instance of our list structure
 329  *
 330  * Return: 0 on success, <0 on failure.
 331  */
 332 int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list)
 333 {
 334
 335         struct mei_cl *cl;
 336         struct mei_cl_cb *cb, *next;
 337         struct mei_cl_cb *list;
 338         s32 slots;
 339         int ret;
 340
 341
 342         if (!mei_hbuf_acquire(dev))
 343                 return 0;
 344
 345         slots = mei_hbuf_empty_slots(dev);
 346         if (slots <= 0)
 347                 return -EMSGSIZE;
 348
 349         /* complete all waiting for write CB */
 350         dev_dbg(dev->dev, "complete all waiting for write cb.\n");
 351
 352         list = &dev->write_waiting_list;
 353         list_for_each_entry_safe(cb, next, &list->list, list) {
 354                 cl = cb->cl;
 355
 356                 cl->status = 0;
 357                 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
 358                 cl->writing_state = MEI_WRITE_COMPLETE;
 359                 list_move_tail(&cb->list, &cmpl_list->list);
 360         }
 361
 362         if (dev->wd_state == MEI_WD_STOPPING) {
 363                 dev->wd_state = MEI_WD_IDLE;
 364                 wake_up(&dev->wait_stop_wd);
 365         }
 366
 367         if (mei_cl_is_connected(&dev->wd_cl)) {
 368                 if (dev->wd_pending &&
 369                     mei_cl_flow_ctrl_creds(&dev->wd_cl) > 0) {
 370                         ret = mei_wd_send(dev);
 371                         if (ret)
 372                                 return ret;
 373                         dev->wd_pending = false;
 374                 }
 375         }
 376
 377         /* complete control write list CB */
 378         dev_dbg(dev->dev, "complete control write list cb.\n");
 379         list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list.list, list) {
 380                 cl = cb->cl;
 381                 switch (cb->fop_type) {
 382                 case MEI_FOP_DISCONNECT:
 383                         /* send disconnect message */
 384                         ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
 385                         if (ret)
 386                                 return ret;
 387
 388                         break;
 389                 case MEI_FOP_READ:
 390                         /* send flow control message */
 391                         ret = mei_cl_irq_read(cl, cb, cmpl_list);
 392                         if (ret)
 393                                 return ret;
 394
 395                         break;
 396                 case MEI_FOP_CONNECT:
 397                         /* connect message */
 398                         ret = mei_cl_irq_connect(cl, cb, cmpl_list);
 399                         if (ret)
 400                                 return ret;
 401
 402                         break;
 403                 case MEI_FOP_DISCONNECT_RSP:
 404                         /* send disconnect resp */
 405                         ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
 406                         if (ret)
 407                                 return ret;
 408                         break;
 409
 410                 case MEI_FOP_NOTIFY_START:
 411                 case MEI_FOP_NOTIFY_STOP:
 412                         ret = mei_cl_irq_notify(cl, cb, cmpl_list);
 413                         if (ret)
 414                                 return ret;
 415                         break;
 416                 default:
 417                         BUG();
 418                 }
 419
 420         }
 421         /* complete  write list CB */
 422         dev_dbg(dev->dev, "complete write list cb.\n");
 423         list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
 424                 cl = cb->cl;
 425                 if (cl == &dev->iamthif_cl)
 426                         ret = mei_amthif_irq_write(cl, cb, cmpl_list);
 427                 else
 428                         ret = mei_cl_irq_write(cl, cb, cmpl_list);
 429                 if (ret)
 430                         return ret;
 431         }
 432         return 0;
 433 }
 434 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
 435
 436
 437 /**
 438  * mei_connect_timeout  - connect/disconnect timeouts
 439  *
 440  * @cl: host client
 441  */
 442 static void mei_connect_timeout(struct mei_cl *cl)
 443 {
 444         struct mei_device *dev = cl->dev;
 445
 446         if (cl->state == MEI_FILE_CONNECTING) {
 447                 if (dev->hbm_f_dot_supported) {
 448                         cl->state = MEI_FILE_DISCONNECT_REQUIRED;
 449                         wake_up(&cl->wait);
 450                         return;
 451                 }
 452         }
 453         mei_reset(dev);
 454 }
 455
 456 /**
 457  * mei_timer - timer function.
 458  *
 459  * @work: pointer to the work_struct structure
 460  *
 461  */
 462 void mei_timer(struct work_struct *work)
 463 {
 464         unsigned long timeout;
 465         struct mei_cl *cl;
 466
 467         struct mei_device *dev = container_of(work,
 468                                         struct mei_device, timer_work.work);
 469
 470
 471         mutex_lock(&dev->device_lock);
 472
 473         /* Catch interrupt stalls during HBM init handshake */
 474         if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
 475             dev->hbm_state != MEI_HBM_IDLE) {
 476
 477                 if (dev->init_clients_timer) {
 478                         if (--dev->init_clients_timer == 0) {
 479                                 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
 480                                         dev->hbm_state);
 481                                 mei_reset(dev);
 482                                 goto out;
 483                         }
 484                 }
 485         }
 486
 487         if (dev->dev_state != MEI_DEV_ENABLED)
 488                 goto out;
 489
 490         /*** connect/disconnect timeouts ***/
 491         list_for_each_entry(cl, &dev->file_list, link) {
 492                 if (cl->timer_count) {
 493                         if (--cl->timer_count == 0) {
 494                                 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
 495                                 mei_connect_timeout(cl);
 496                                 goto out;
 497                         }
 498                 }
 499         }
 500
 501         if (!mei_cl_is_connected(&dev->iamthif_cl))
 502                 goto out;
 503
 504         if (dev->iamthif_stall_timer) {
 505                 if (--dev->iamthif_stall_timer == 0) {
 506                         dev_err(dev->dev, "timer: amthif  hanged.\n");
 507                         mei_reset(dev);
 508                         dev->iamthif_canceled = false;
 509                         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 510                         dev->iamthif_timer = 0;
 511
 512                         mei_io_cb_free(dev->iamthif_current_cb);
 513                         dev->iamthif_current_cb = NULL;
 514
 515                         dev->iamthif_file_object = NULL;
 516                         mei_amthif_run_next_cmd(dev);
 517                 }
 518         }
 519
 520         if (dev->iamthif_timer) {
 521
 522                 timeout = dev->iamthif_timer +
 523                         mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
 524
 525                 dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
 526                                 dev->iamthif_timer);
 527                 dev_dbg(dev->dev, "timeout = %ld\n", timeout);
 528                 dev_dbg(dev->dev, "jiffies = %ld\n", jiffies);
 529                 if (time_after(jiffies, timeout)) {
 530                         /*
 531                          * User didn't read the AMTHI data on time (15sec)
 532                          * freeing AMTHI for other requests
 533                          */
 534
 535                         dev_dbg(dev->dev, "freeing AMTHI for other requests\n");
 536
 537                         mei_io_list_flush(&dev->amthif_rd_complete_list,
 538                                 &dev->iamthif_cl);
 539                         mei_io_cb_free(dev->iamthif_current_cb);
 540                         dev->iamthif_current_cb = NULL;
 541
 542                         dev->iamthif_file_object->private_data = NULL;
 543                         dev->iamthif_file_object = NULL;
 544                         dev->iamthif_timer = 0;
 545                         mei_amthif_run_next_cmd(dev);
 546
 547                 }
 548         }
 549 out:
 550         if (dev->dev_state != MEI_DEV_DISABLED)
 551                 schedule_delayed_work(&dev->timer_work, 2 * HZ);
 552         mutex_unlock(&dev->device_lock);
 553 }