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