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 list_move_tail(&cb->list, &complete_list->list); 122 cb->status = -ENODEV; 123 goto discard; 124 } 125 126 buf_sz = mei_hdr->length + cb->buf_idx; 127 /* catch for integer overflow */ 128 if (buf_sz < cb->buf_idx) { 129 cl_err(dev, cl, "message is too big len %d idx %zu\n", 130 mei_hdr->length, cb->buf_idx); 131 132 list_move_tail(&cb->list, &complete_list->list); 133 cb->status = -EMSGSIZE; 134 goto discard; 135 } 136 137 if (cb->buf.size < buf_sz) { 138 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n", 139 cb->buf.size, mei_hdr->length, cb->buf_idx); 140 141 list_move_tail(&cb->list, &complete_list->list); 142 cb->status = -EMSGSIZE; 143 goto discard; 144 } 145 146 mei_read_slots(dev, cb->buf.data + cb->buf_idx, mei_hdr->length); 147 148 cb->buf_idx += mei_hdr->length; 149 150 if (mei_hdr->msg_complete) { 151 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx); 152 list_move_tail(&cb->list, &complete_list->list); 153 } else { 154 pm_runtime_mark_last_busy(dev->dev); 155 pm_request_autosuspend(dev->dev); 156 } 157 158 return 0; 159 160 discard: 161 mei_irq_discard_msg(dev, mei_hdr); 162 return 0; 163 } 164 165 /** 166 * mei_cl_irq_disconnect_rsp - send disconnection response message 167 * 168 * @cl: client 169 * @cb: callback block. 170 * @cmpl_list: complete list. 171 * 172 * Return: 0, OK; otherwise, error. 173 */ 174 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb, 175 struct mei_cl_cb *cmpl_list) 176 { 177 struct mei_device *dev = cl->dev; 178 u32 msg_slots; 179 int slots; 180 int ret; 181 182 slots = mei_hbuf_empty_slots(dev); 183 msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_response)); 184 185 if (slots < msg_slots) 186 return -EMSGSIZE; 187 188 ret = mei_hbm_cl_disconnect_rsp(dev, cl); 189 list_move_tail(&cb->list, &cmpl_list->list); 190 191 return ret; 192 } 193 194 /** 195 * mei_cl_irq_read - processes client read related operation from the 196 * interrupt thread context - request for flow control credits 197 * 198 * @cl: client 199 * @cb: callback block. 200 * @cmpl_list: complete list. 201 * 202 * Return: 0, OK; otherwise, error. 203 */ 204 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb, 205 struct mei_cl_cb *cmpl_list) 206 { 207 struct mei_device *dev = cl->dev; 208 u32 msg_slots; 209 int slots; 210 int ret; 211 212 if (!list_empty(&cl->rd_pending)) 213 return 0; 214 215 msg_slots = mei_data2slots(sizeof(struct hbm_flow_control)); 216 slots = mei_hbuf_empty_slots(dev); 217 218 if (slots < msg_slots) 219 return -EMSGSIZE; 220 221 ret = mei_hbm_cl_flow_control_req(dev, cl); 222 if (ret) { 223 cl->status = ret; 224 cb->buf_idx = 0; 225 list_move_tail(&cb->list, &cmpl_list->list); 226 return ret; 227 } 228 229 list_move_tail(&cb->list, &cl->rd_pending); 230 231 return 0; 232 } 233 234 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr) 235 { 236 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0; 237 } 238 239 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr) 240 { 241 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0; 242 } 243 244 /** 245 * mei_irq_read_handler - bottom half read routine after ISR to 246 * handle the read processing. 247 * 248 * @dev: the device structure 249 * @cmpl_list: An instance of our list structure 250 * @slots: slots to read. 251 * 252 * Return: 0 on success, <0 on failure. 253 */ 254 int mei_irq_read_handler(struct mei_device *dev, 255 struct mei_cl_cb *cmpl_list, s32 *slots) 256 { 257 struct mei_msg_hdr *mei_hdr; 258 struct mei_cl *cl; 259 int ret; 260 261 if (!dev->rd_msg_hdr) { 262 dev->rd_msg_hdr = mei_read_hdr(dev); 263 (*slots)--; 264 dev_dbg(dev->dev, "slots =%08x.\n", *slots); 265 } 266 mei_hdr = (struct mei_msg_hdr *) &dev->rd_msg_hdr; 267 dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr)); 268 269 if (mei_hdr->reserved || !dev->rd_msg_hdr) { 270 dev_err(dev->dev, "corrupted message header 0x%08X\n", 271 dev->rd_msg_hdr); 272 ret = -EBADMSG; 273 goto end; 274 } 275 276 if (mei_slots2data(*slots) < mei_hdr->length) { 277 dev_err(dev->dev, "less data available than length=%08x.\n", 278 *slots); 279 /* we can't read the message */ 280 ret = -ENODATA; 281 goto end; 282 } 283 284 /* HBM message */ 285 if (hdr_is_hbm(mei_hdr)) { 286 ret = mei_hbm_dispatch(dev, mei_hdr); 287 if (ret) { 288 dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n", 289 ret); 290 goto end; 291 } 292 goto reset_slots; 293 } 294 295 /* find recipient cl */ 296 list_for_each_entry(cl, &dev->file_list, link) { 297 if (mei_cl_hbm_equal(cl, mei_hdr)) { 298 cl_dbg(dev, cl, "got a message\n"); 299 break; 300 } 301 } 302 303 /* if no recipient cl was found we assume corrupted header */ 304 if (&cl->link == &dev->file_list) { 305 /* A message for not connected fixed address clients 306 * should be silently discarded 307 */ 308 if (hdr_is_fixed(mei_hdr)) { 309 mei_irq_discard_msg(dev, mei_hdr); 310 ret = 0; 311 goto reset_slots; 312 } 313 dev_err(dev->dev, "no destination client found 0x%08X\n", 314 dev->rd_msg_hdr); 315 ret = -EBADMSG; 316 goto end; 317 } 318 319 if (cl == &dev->iamthif_cl) { 320 ret = mei_amthif_irq_read_msg(cl, mei_hdr, cmpl_list); 321 } else { 322 ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list); 323 } 324 325 326 reset_slots: 327 /* reset the number of slots and header */ 328 *slots = mei_count_full_read_slots(dev); 329 dev->rd_msg_hdr = 0; 330 331 if (*slots == -EOVERFLOW) { 332 /* overflow - reset */ 333 dev_err(dev->dev, "resetting due to slots overflow.\n"); 334 /* set the event since message has been read */ 335 ret = -ERANGE; 336 goto end; 337 } 338 end: 339 return ret; 340 } 341 EXPORT_SYMBOL_GPL(mei_irq_read_handler); 342 343 344 /** 345 * mei_irq_write_handler - dispatch write requests 346 * after irq received 347 * 348 * @dev: the device structure 349 * @cmpl_list: An instance of our list structure 350 * 351 * Return: 0 on success, <0 on failure. 352 */ 353 int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list) 354 { 355 356 struct mei_cl *cl; 357 struct mei_cl_cb *cb, *next; 358 struct mei_cl_cb *list; 359 s32 slots; 360 int ret; 361 362 363 if (!mei_hbuf_acquire(dev)) 364 return 0; 365 366 slots = mei_hbuf_empty_slots(dev); 367 if (slots <= 0) 368 return -EMSGSIZE; 369 370 /* complete all waiting for write CB */ 371 dev_dbg(dev->dev, "complete all waiting for write cb.\n"); 372 373 list = &dev->write_waiting_list; 374 list_for_each_entry_safe(cb, next, &list->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->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, 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, list) { 430 cl = cb->cl; 431 if (cl == &dev->iamthif_cl) 432 ret = mei_amthif_irq_write(cl, cb, cmpl_list); 433 else 434 ret = mei_cl_irq_write(cl, cb, cmpl_list); 435 if (ret) 436 return ret; 437 } 438 return 0; 439 } 440 EXPORT_SYMBOL_GPL(mei_irq_write_handler); 441 442 443 /** 444 * mei_connect_timeout - connect/disconnect timeouts 445 * 446 * @cl: host client 447 */ 448 static void mei_connect_timeout(struct mei_cl *cl) 449 { 450 struct mei_device *dev = cl->dev; 451 452 if (cl->state == MEI_FILE_CONNECTING) { 453 if (dev->hbm_f_dot_supported) { 454 cl->state = MEI_FILE_DISCONNECT_REQUIRED; 455 wake_up(&cl->wait); 456 return; 457 } 458 } 459 mei_reset(dev); 460 } 461 462 #define MEI_STALL_TIMER_FREQ (2 * HZ) 463 /** 464 * mei_schedule_stall_timer - re-arm stall_timer work 465 * 466 * Schedule stall timer 467 * 468 * @dev: the device structure 469 */ 470 void mei_schedule_stall_timer(struct mei_device *dev) 471 { 472 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ); 473 } 474 475 /** 476 * mei_timer - timer function. 477 * 478 * @work: pointer to the work_struct structure 479 * 480 */ 481 void mei_timer(struct work_struct *work) 482 { 483 struct mei_cl *cl; 484 struct mei_device *dev = container_of(work, 485 struct mei_device, timer_work.work); 486 bool reschedule_timer = false; 487 488 mutex_lock(&dev->device_lock); 489 490 /* Catch interrupt stalls during HBM init handshake */ 491 if (dev->dev_state == MEI_DEV_INIT_CLIENTS && 492 dev->hbm_state != MEI_HBM_IDLE) { 493 494 if (dev->init_clients_timer) { 495 if (--dev->init_clients_timer == 0) { 496 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n", 497 dev->hbm_state); 498 mei_reset(dev); 499 goto out; 500 } 501 reschedule_timer = true; 502 } 503 } 504 505 if (dev->dev_state != MEI_DEV_ENABLED) 506 goto out; 507 508 /*** connect/disconnect timeouts ***/ 509 list_for_each_entry(cl, &dev->file_list, link) { 510 if (cl->timer_count) { 511 if (--cl->timer_count == 0) { 512 dev_err(dev->dev, "timer: connect/disconnect timeout.\n"); 513 mei_connect_timeout(cl); 514 goto out; 515 } 516 reschedule_timer = true; 517 } 518 } 519 520 if (!mei_cl_is_connected(&dev->iamthif_cl)) 521 goto out; 522 523 if (dev->iamthif_stall_timer) { 524 if (--dev->iamthif_stall_timer == 0) { 525 dev_err(dev->dev, "timer: amthif hanged.\n"); 526 mei_reset(dev); 527 528 mei_amthif_run_next_cmd(dev); 529 goto out; 530 } 531 reschedule_timer = true; 532 } 533 534 out: 535 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer) 536 mei_schedule_stall_timer(dev); 537 538 mutex_unlock(&dev->device_lock); 539 } 540