1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2003-2018, Intel Corporation. All rights reserved. 4 * Intel Management Engine Interface (Intel MEI) Linux driver 5 */ 6 7 #include <linux/export.h> 8 #include <linux/kthread.h> 9 #include <linux/interrupt.h> 10 #include <linux/fs.h> 11 #include <linux/jiffies.h> 12 #include <linux/slab.h> 13 #include <linux/pm_runtime.h> 14 15 #include <linux/mei.h> 16 17 #include "mei_dev.h" 18 #include "hbm.h" 19 #include "client.h" 20 21 22 /** 23 * mei_irq_compl_handler - dispatch complete handlers 24 * for the completed callbacks 25 * 26 * @dev: mei device 27 * @cmpl_list: list of completed cbs 28 */ 29 void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list) 30 { 31 struct mei_cl_cb *cb, *next; 32 struct mei_cl *cl; 33 34 list_for_each_entry_safe(cb, next, cmpl_list, list) { 35 cl = cb->cl; 36 list_del_init(&cb->list); 37 38 dev_dbg(dev->dev, "completing call back.\n"); 39 mei_cl_complete(cl, cb); 40 } 41 } 42 EXPORT_SYMBOL_GPL(mei_irq_compl_handler); 43 44 /** 45 * mei_cl_hbm_equal - check if hbm is addressed to the client 46 * 47 * @cl: host client 48 * @mei_hdr: header of mei client message 49 * 50 * Return: true if matches, false otherwise 51 */ 52 static inline int mei_cl_hbm_equal(struct mei_cl *cl, 53 struct mei_msg_hdr *mei_hdr) 54 { 55 return mei_cl_host_addr(cl) == mei_hdr->host_addr && 56 mei_cl_me_id(cl) == mei_hdr->me_addr; 57 } 58 59 /** 60 * mei_irq_discard_msg - discard received message 61 * 62 * @dev: mei device 63 * @hdr: message header 64 * @discard_len: the length of the message to discard (excluding header) 65 */ 66 static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr, 67 size_t discard_len) 68 { 69 if (hdr->dma_ring) { 70 mei_dma_ring_read(dev, NULL, 71 hdr->extension[dev->rd_msg_hdr_count - 2]); 72 discard_len = 0; 73 } 74 /* 75 * no need to check for size as it is guarantied 76 * that length fits into rd_msg_buf 77 */ 78 mei_read_slots(dev, dev->rd_msg_buf, discard_len); 79 dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n", 80 MEI_HDR_PRM(hdr)); 81 } 82 83 /** 84 * mei_cl_irq_read_msg - process client message 85 * 86 * @cl: reading client 87 * @mei_hdr: header of mei client message 88 * @meta: extend meta header 89 * @cmpl_list: completion list 90 * 91 * Return: always 0 92 */ 93 static int mei_cl_irq_read_msg(struct mei_cl *cl, 94 struct mei_msg_hdr *mei_hdr, 95 struct mei_ext_meta_hdr *meta, 96 struct list_head *cmpl_list) 97 { 98 struct mei_device *dev = cl->dev; 99 struct mei_cl_cb *cb; 100 101 size_t buf_sz; 102 u32 length; 103 int ext_len; 104 105 length = mei_hdr->length; 106 ext_len = 0; 107 if (mei_hdr->extended) { 108 ext_len = sizeof(*meta) + mei_slots2data(meta->size); 109 length -= ext_len; 110 } 111 112 cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list); 113 if (!cb) { 114 if (!mei_cl_is_fixed_address(cl)) { 115 cl_err(dev, cl, "pending read cb not found\n"); 116 goto discard; 117 } 118 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp); 119 if (!cb) 120 goto discard; 121 list_add_tail(&cb->list, &cl->rd_pending); 122 } 123 124 if (mei_hdr->extended) { 125 struct mei_ext_hdr *ext; 126 struct mei_ext_hdr *vtag = NULL; 127 128 ext = mei_ext_begin(meta); 129 do { 130 switch (ext->type) { 131 case MEI_EXT_HDR_VTAG: 132 vtag = ext; 133 break; 134 case MEI_EXT_HDR_NONE: 135 fallthrough; 136 default: 137 cb->status = -EPROTO; 138 break; 139 } 140 141 ext = mei_ext_next(ext); 142 } while (!mei_ext_last(meta, ext)); 143 144 if (!vtag) { 145 cl_dbg(dev, cl, "vtag not found in extended header.\n"); 146 cb->status = -EPROTO; 147 goto discard; 148 } 149 150 cl_dbg(dev, cl, "vtag: %d\n", vtag->ext_payload[0]); 151 if (cb->vtag && cb->vtag != vtag->ext_payload[0]) { 152 cl_err(dev, cl, "mismatched tag: %d != %d\n", 153 cb->vtag, vtag->ext_payload[0]); 154 cb->status = -EPROTO; 155 goto discard; 156 } 157 cb->vtag = vtag->ext_payload[0]; 158 } 159 160 if (!mei_cl_is_connected(cl)) { 161 cl_dbg(dev, cl, "not connected\n"); 162 cb->status = -ENODEV; 163 goto discard; 164 } 165 166 if (mei_hdr->dma_ring) 167 length = mei_hdr->extension[mei_data2slots(ext_len)]; 168 169 buf_sz = length + cb->buf_idx; 170 /* catch for integer overflow */ 171 if (buf_sz < cb->buf_idx) { 172 cl_err(dev, cl, "message is too big len %d idx %zu\n", 173 length, cb->buf_idx); 174 cb->status = -EMSGSIZE; 175 goto discard; 176 } 177 178 if (cb->buf.size < buf_sz) { 179 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n", 180 cb->buf.size, length, cb->buf_idx); 181 cb->status = -EMSGSIZE; 182 goto discard; 183 } 184 185 if (mei_hdr->dma_ring) { 186 mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length); 187 /* for DMA read 0 length to generate interrupt to the device */ 188 mei_read_slots(dev, cb->buf.data + cb->buf_idx, 0); 189 } else { 190 mei_read_slots(dev, cb->buf.data + cb->buf_idx, length); 191 } 192 193 cb->buf_idx += length; 194 195 if (mei_hdr->msg_complete) { 196 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx); 197 list_move_tail(&cb->list, cmpl_list); 198 } else { 199 pm_runtime_mark_last_busy(dev->dev); 200 pm_request_autosuspend(dev->dev); 201 } 202 203 return 0; 204 205 discard: 206 if (cb) 207 list_move_tail(&cb->list, cmpl_list); 208 mei_irq_discard_msg(dev, mei_hdr, length); 209 return 0; 210 } 211 212 /** 213 * mei_cl_irq_disconnect_rsp - send disconnection response message 214 * 215 * @cl: client 216 * @cb: callback block. 217 * @cmpl_list: complete list. 218 * 219 * Return: 0, OK; otherwise, error. 220 */ 221 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb, 222 struct list_head *cmpl_list) 223 { 224 struct mei_device *dev = cl->dev; 225 u32 msg_slots; 226 int slots; 227 int ret; 228 229 msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response)); 230 slots = mei_hbuf_empty_slots(dev); 231 if (slots < 0) 232 return -EOVERFLOW; 233 234 if ((u32)slots < msg_slots) 235 return -EMSGSIZE; 236 237 ret = mei_hbm_cl_disconnect_rsp(dev, cl); 238 list_move_tail(&cb->list, cmpl_list); 239 240 return ret; 241 } 242 243 /** 244 * mei_cl_irq_read - processes client read related operation from the 245 * interrupt thread context - request for flow control credits 246 * 247 * @cl: client 248 * @cb: callback block. 249 * @cmpl_list: complete list. 250 * 251 * Return: 0, OK; otherwise, error. 252 */ 253 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb, 254 struct list_head *cmpl_list) 255 { 256 struct mei_device *dev = cl->dev; 257 u32 msg_slots; 258 int slots; 259 int ret; 260 261 if (!list_empty(&cl->rd_pending)) 262 return 0; 263 264 msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control)); 265 slots = mei_hbuf_empty_slots(dev); 266 if (slots < 0) 267 return -EOVERFLOW; 268 269 if ((u32)slots < msg_slots) 270 return -EMSGSIZE; 271 272 ret = mei_hbm_cl_flow_control_req(dev, cl); 273 if (ret) { 274 cl->status = ret; 275 cb->buf_idx = 0; 276 list_move_tail(&cb->list, cmpl_list); 277 return ret; 278 } 279 280 list_move_tail(&cb->list, &cl->rd_pending); 281 282 return 0; 283 } 284 285 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr) 286 { 287 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0; 288 } 289 290 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr) 291 { 292 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0; 293 } 294 295 static inline int hdr_is_valid(u32 msg_hdr) 296 { 297 struct mei_msg_hdr *mei_hdr; 298 u32 expected_len = 0; 299 300 mei_hdr = (struct mei_msg_hdr *)&msg_hdr; 301 if (!msg_hdr || mei_hdr->reserved) 302 return -EBADMSG; 303 304 if (mei_hdr->dma_ring) 305 expected_len += MEI_SLOT_SIZE; 306 if (mei_hdr->extended) 307 expected_len += MEI_SLOT_SIZE; 308 if (mei_hdr->length < expected_len) 309 return -EBADMSG; 310 311 return 0; 312 } 313 314 /** 315 * mei_irq_read_handler - bottom half read routine after ISR to 316 * handle the read processing. 317 * 318 * @dev: the device structure 319 * @cmpl_list: An instance of our list structure 320 * @slots: slots to read. 321 * 322 * Return: 0 on success, <0 on failure. 323 */ 324 int mei_irq_read_handler(struct mei_device *dev, 325 struct list_head *cmpl_list, s32 *slots) 326 { 327 struct mei_msg_hdr *mei_hdr; 328 struct mei_ext_meta_hdr *meta_hdr = NULL; 329 struct mei_cl *cl; 330 int ret; 331 u32 ext_meta_hdr_u32; 332 u32 hdr_size_left; 333 u32 hdr_size_ext; 334 int i; 335 int ext_hdr_end; 336 337 if (!dev->rd_msg_hdr[0]) { 338 dev->rd_msg_hdr[0] = mei_read_hdr(dev); 339 dev->rd_msg_hdr_count = 1; 340 (*slots)--; 341 dev_dbg(dev->dev, "slots =%08x.\n", *slots); 342 343 ret = hdr_is_valid(dev->rd_msg_hdr[0]); 344 if (ret) { 345 dev_err(dev->dev, "corrupted message header 0x%08X\n", 346 dev->rd_msg_hdr[0]); 347 goto end; 348 } 349 } 350 351 mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr; 352 dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr)); 353 354 if (mei_slots2data(*slots) < mei_hdr->length) { 355 dev_err(dev->dev, "less data available than length=%08x.\n", 356 *slots); 357 /* we can't read the message */ 358 ret = -ENODATA; 359 goto end; 360 } 361 362 ext_hdr_end = 1; 363 hdr_size_left = mei_hdr->length; 364 365 if (mei_hdr->extended) { 366 if (!dev->rd_msg_hdr[1]) { 367 ext_meta_hdr_u32 = mei_read_hdr(dev); 368 dev->rd_msg_hdr[1] = ext_meta_hdr_u32; 369 dev->rd_msg_hdr_count++; 370 (*slots)--; 371 dev_dbg(dev->dev, "extended header is %08x\n", 372 ext_meta_hdr_u32); 373 } 374 meta_hdr = ((struct mei_ext_meta_hdr *)dev->rd_msg_hdr + 1); 375 if (check_add_overflow((u32)sizeof(*meta_hdr), 376 mei_slots2data(meta_hdr->size), 377 &hdr_size_ext)) { 378 dev_err(dev->dev, "extended message size too big %d\n", 379 meta_hdr->size); 380 return -EBADMSG; 381 } 382 if (hdr_size_left < hdr_size_ext) { 383 dev_err(dev->dev, "corrupted message header len %d\n", 384 mei_hdr->length); 385 return -EBADMSG; 386 } 387 hdr_size_left -= hdr_size_ext; 388 389 ext_hdr_end = meta_hdr->size + 2; 390 for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) { 391 dev->rd_msg_hdr[i] = mei_read_hdr(dev); 392 dev_dbg(dev->dev, "extended header %d is %08x\n", i, 393 dev->rd_msg_hdr[i]); 394 dev->rd_msg_hdr_count++; 395 (*slots)--; 396 } 397 } 398 399 if (mei_hdr->dma_ring) { 400 if (hdr_size_left != sizeof(dev->rd_msg_hdr[ext_hdr_end])) { 401 dev_err(dev->dev, "corrupted message header len %d\n", 402 mei_hdr->length); 403 return -EBADMSG; 404 } 405 406 dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev); 407 dev->rd_msg_hdr_count++; 408 (*slots)--; 409 mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]); 410 } 411 412 /* HBM message */ 413 if (hdr_is_hbm(mei_hdr)) { 414 ret = mei_hbm_dispatch(dev, mei_hdr); 415 if (ret) { 416 dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n", 417 ret); 418 goto end; 419 } 420 goto reset_slots; 421 } 422 423 /* find recipient cl */ 424 list_for_each_entry(cl, &dev->file_list, link) { 425 if (mei_cl_hbm_equal(cl, mei_hdr)) { 426 cl_dbg(dev, cl, "got a message\n"); 427 break; 428 } 429 } 430 431 /* if no recipient cl was found we assume corrupted header */ 432 if (&cl->link == &dev->file_list) { 433 /* A message for not connected fixed address clients 434 * should be silently discarded 435 * On power down client may be force cleaned, 436 * silently discard such messages 437 */ 438 if (hdr_is_fixed(mei_hdr) || 439 dev->dev_state == MEI_DEV_POWER_DOWN) { 440 mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length); 441 ret = 0; 442 goto reset_slots; 443 } 444 dev_err(dev->dev, "no destination client found 0x%08X\n", 445 dev->rd_msg_hdr[0]); 446 ret = -EBADMSG; 447 goto end; 448 } 449 450 ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list); 451 452 453 reset_slots: 454 /* reset the number of slots and header */ 455 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr)); 456 dev->rd_msg_hdr_count = 0; 457 *slots = mei_count_full_read_slots(dev); 458 if (*slots == -EOVERFLOW) { 459 /* overflow - reset */ 460 dev_err(dev->dev, "resetting due to slots overflow.\n"); 461 /* set the event since message has been read */ 462 ret = -ERANGE; 463 goto end; 464 } 465 end: 466 return ret; 467 } 468 EXPORT_SYMBOL_GPL(mei_irq_read_handler); 469 470 471 /** 472 * mei_irq_write_handler - dispatch write requests 473 * after irq received 474 * 475 * @dev: the device structure 476 * @cmpl_list: An instance of our list structure 477 * 478 * Return: 0 on success, <0 on failure. 479 */ 480 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list) 481 { 482 483 struct mei_cl *cl; 484 struct mei_cl_cb *cb, *next; 485 s32 slots; 486 int ret; 487 488 489 if (!mei_hbuf_acquire(dev)) 490 return 0; 491 492 slots = mei_hbuf_empty_slots(dev); 493 if (slots < 0) 494 return -EOVERFLOW; 495 496 if (slots == 0) 497 return -EMSGSIZE; 498 499 /* complete all waiting for write CB */ 500 dev_dbg(dev->dev, "complete all waiting for write cb.\n"); 501 502 list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) { 503 cl = cb->cl; 504 505 cl->status = 0; 506 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n"); 507 cl->writing_state = MEI_WRITE_COMPLETE; 508 list_move_tail(&cb->list, cmpl_list); 509 } 510 511 /* complete control write list CB */ 512 dev_dbg(dev->dev, "complete control write list cb.\n"); 513 list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) { 514 cl = cb->cl; 515 switch (cb->fop_type) { 516 case MEI_FOP_DISCONNECT: 517 /* send disconnect message */ 518 ret = mei_cl_irq_disconnect(cl, cb, cmpl_list); 519 if (ret) 520 return ret; 521 522 break; 523 case MEI_FOP_READ: 524 /* send flow control message */ 525 ret = mei_cl_irq_read(cl, cb, cmpl_list); 526 if (ret) 527 return ret; 528 529 break; 530 case MEI_FOP_CONNECT: 531 /* connect message */ 532 ret = mei_cl_irq_connect(cl, cb, cmpl_list); 533 if (ret) 534 return ret; 535 536 break; 537 case MEI_FOP_DISCONNECT_RSP: 538 /* send disconnect resp */ 539 ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list); 540 if (ret) 541 return ret; 542 break; 543 544 case MEI_FOP_NOTIFY_START: 545 case MEI_FOP_NOTIFY_STOP: 546 ret = mei_cl_irq_notify(cl, cb, cmpl_list); 547 if (ret) 548 return ret; 549 break; 550 case MEI_FOP_DMA_MAP: 551 ret = mei_cl_irq_dma_map(cl, cb, cmpl_list); 552 if (ret) 553 return ret; 554 break; 555 case MEI_FOP_DMA_UNMAP: 556 ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list); 557 if (ret) 558 return ret; 559 break; 560 default: 561 BUG(); 562 } 563 564 } 565 /* complete write list CB */ 566 dev_dbg(dev->dev, "complete write list cb.\n"); 567 list_for_each_entry_safe(cb, next, &dev->write_list, list) { 568 cl = cb->cl; 569 ret = mei_cl_irq_write(cl, cb, cmpl_list); 570 if (ret) 571 return ret; 572 } 573 return 0; 574 } 575 EXPORT_SYMBOL_GPL(mei_irq_write_handler); 576 577 578 /** 579 * mei_connect_timeout - connect/disconnect timeouts 580 * 581 * @cl: host client 582 */ 583 static void mei_connect_timeout(struct mei_cl *cl) 584 { 585 struct mei_device *dev = cl->dev; 586 587 if (cl->state == MEI_FILE_CONNECTING) { 588 if (dev->hbm_f_dot_supported) { 589 cl->state = MEI_FILE_DISCONNECT_REQUIRED; 590 wake_up(&cl->wait); 591 return; 592 } 593 } 594 mei_reset(dev); 595 } 596 597 #define MEI_STALL_TIMER_FREQ (2 * HZ) 598 /** 599 * mei_schedule_stall_timer - re-arm stall_timer work 600 * 601 * Schedule stall timer 602 * 603 * @dev: the device structure 604 */ 605 void mei_schedule_stall_timer(struct mei_device *dev) 606 { 607 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ); 608 } 609 610 /** 611 * mei_timer - timer function. 612 * 613 * @work: pointer to the work_struct structure 614 * 615 */ 616 void mei_timer(struct work_struct *work) 617 { 618 struct mei_cl *cl; 619 struct mei_device *dev = container_of(work, 620 struct mei_device, timer_work.work); 621 bool reschedule_timer = false; 622 623 mutex_lock(&dev->device_lock); 624 625 /* Catch interrupt stalls during HBM init handshake */ 626 if (dev->dev_state == MEI_DEV_INIT_CLIENTS && 627 dev->hbm_state != MEI_HBM_IDLE) { 628 629 if (dev->init_clients_timer) { 630 if (--dev->init_clients_timer == 0) { 631 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n", 632 dev->hbm_state); 633 mei_reset(dev); 634 goto out; 635 } 636 reschedule_timer = true; 637 } 638 } 639 640 if (dev->dev_state != MEI_DEV_ENABLED) 641 goto out; 642 643 /*** connect/disconnect timeouts ***/ 644 list_for_each_entry(cl, &dev->file_list, link) { 645 if (cl->timer_count) { 646 if (--cl->timer_count == 0) { 647 dev_err(dev->dev, "timer: connect/disconnect timeout.\n"); 648 mei_connect_timeout(cl); 649 goto out; 650 } 651 reschedule_timer = true; 652 } 653 } 654 655 out: 656 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer) 657 mei_schedule_stall_timer(dev); 658 659 mutex_unlock(&dev->device_lock); 660 } 661