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