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 *vtag_hdr = NULL; 127 128 ext = mei_ext_begin(meta); 129 do { 130 switch (ext->type) { 131 case MEI_EXT_HDR_VTAG: 132 vtag_hdr = (struct mei_ext_hdr_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_hdr) { 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_hdr->vtag); 151 if (cb->vtag && cb->vtag != vtag_hdr->vtag) { 152 cl_err(dev, cl, "mismatched tag: %d != %d\n", 153 cb->vtag, vtag_hdr->vtag); 154 cb->status = -EPROTO; 155 goto discard; 156 } 157 cb->vtag = vtag_hdr->vtag; 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 pm_runtime_mark_last_busy(dev->dev); 281 pm_request_autosuspend(dev->dev); 282 283 list_move_tail(&cb->list, &cl->rd_pending); 284 285 return 0; 286 } 287 288 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr) 289 { 290 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0; 291 } 292 293 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr) 294 { 295 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0; 296 } 297 298 static inline int hdr_is_valid(u32 msg_hdr) 299 { 300 struct mei_msg_hdr *mei_hdr; 301 u32 expected_len = 0; 302 303 mei_hdr = (struct mei_msg_hdr *)&msg_hdr; 304 if (!msg_hdr || mei_hdr->reserved) 305 return -EBADMSG; 306 307 if (mei_hdr->dma_ring) 308 expected_len += MEI_SLOT_SIZE; 309 if (mei_hdr->extended) 310 expected_len += MEI_SLOT_SIZE; 311 if (mei_hdr->length < expected_len) 312 return -EBADMSG; 313 314 return 0; 315 } 316 317 /** 318 * mei_irq_read_handler - bottom half read routine after ISR to 319 * handle the read processing. 320 * 321 * @dev: the device structure 322 * @cmpl_list: An instance of our list structure 323 * @slots: slots to read. 324 * 325 * Return: 0 on success, <0 on failure. 326 */ 327 int mei_irq_read_handler(struct mei_device *dev, 328 struct list_head *cmpl_list, s32 *slots) 329 { 330 struct mei_msg_hdr *mei_hdr; 331 struct mei_ext_meta_hdr *meta_hdr = NULL; 332 struct mei_cl *cl; 333 int ret; 334 u32 hdr_size_left; 335 u32 hdr_size_ext; 336 int i; 337 int ext_hdr_end; 338 339 if (!dev->rd_msg_hdr[0]) { 340 dev->rd_msg_hdr[0] = mei_read_hdr(dev); 341 dev->rd_msg_hdr_count = 1; 342 (*slots)--; 343 dev_dbg(dev->dev, "slots =%08x.\n", *slots); 344 345 ret = hdr_is_valid(dev->rd_msg_hdr[0]); 346 if (ret) { 347 dev_err(dev->dev, "corrupted message header 0x%08X\n", 348 dev->rd_msg_hdr[0]); 349 goto end; 350 } 351 } 352 353 mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr; 354 dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr)); 355 356 if (mei_slots2data(*slots) < mei_hdr->length) { 357 dev_err(dev->dev, "less data available than length=%08x.\n", 358 *slots); 359 /* we can't read the message */ 360 ret = -ENODATA; 361 goto end; 362 } 363 364 ext_hdr_end = 1; 365 hdr_size_left = mei_hdr->length; 366 367 if (mei_hdr->extended) { 368 if (!dev->rd_msg_hdr[1]) { 369 dev->rd_msg_hdr[1] = mei_read_hdr(dev); 370 dev->rd_msg_hdr_count++; 371 (*slots)--; 372 dev_dbg(dev->dev, "extended header is %08x\n", dev->rd_msg_hdr[1]); 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 ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list); 428 goto reset_slots; 429 } 430 } 431 432 /* if no recipient cl was found we assume corrupted header */ 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", dev->rd_msg_hdr[0]); 445 ret = -EBADMSG; 446 goto end; 447 448 reset_slots: 449 /* reset the number of slots and header */ 450 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr)); 451 dev->rd_msg_hdr_count = 0; 452 *slots = mei_count_full_read_slots(dev); 453 if (*slots == -EOVERFLOW) { 454 /* overflow - reset */ 455 dev_err(dev->dev, "resetting due to slots overflow.\n"); 456 /* set the event since message has been read */ 457 ret = -ERANGE; 458 goto end; 459 } 460 end: 461 return ret; 462 } 463 EXPORT_SYMBOL_GPL(mei_irq_read_handler); 464 465 466 /** 467 * mei_irq_write_handler - dispatch write requests 468 * after irq received 469 * 470 * @dev: the device structure 471 * @cmpl_list: An instance of our list structure 472 * 473 * Return: 0 on success, <0 on failure. 474 */ 475 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list) 476 { 477 478 struct mei_cl *cl; 479 struct mei_cl_cb *cb, *next; 480 s32 slots; 481 int ret; 482 483 484 if (!mei_hbuf_acquire(dev)) 485 return 0; 486 487 slots = mei_hbuf_empty_slots(dev); 488 if (slots < 0) 489 return -EOVERFLOW; 490 491 if (slots == 0) 492 return -EMSGSIZE; 493 494 /* complete all waiting for write CB */ 495 dev_dbg(dev->dev, "complete all waiting for write cb.\n"); 496 497 list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) { 498 cl = cb->cl; 499 500 cl->status = 0; 501 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n"); 502 cl->writing_state = MEI_WRITE_COMPLETE; 503 list_move_tail(&cb->list, cmpl_list); 504 } 505 506 /* complete control write list CB */ 507 dev_dbg(dev->dev, "complete control write list cb.\n"); 508 list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) { 509 cl = cb->cl; 510 switch (cb->fop_type) { 511 case MEI_FOP_DISCONNECT: 512 /* send disconnect message */ 513 ret = mei_cl_irq_disconnect(cl, cb, cmpl_list); 514 if (ret) 515 return ret; 516 517 break; 518 case MEI_FOP_READ: 519 /* send flow control message */ 520 ret = mei_cl_irq_read(cl, cb, cmpl_list); 521 if (ret) 522 return ret; 523 524 break; 525 case MEI_FOP_CONNECT: 526 /* connect message */ 527 ret = mei_cl_irq_connect(cl, cb, cmpl_list); 528 if (ret) 529 return ret; 530 531 break; 532 case MEI_FOP_DISCONNECT_RSP: 533 /* send disconnect resp */ 534 ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list); 535 if (ret) 536 return ret; 537 break; 538 539 case MEI_FOP_NOTIFY_START: 540 case MEI_FOP_NOTIFY_STOP: 541 ret = mei_cl_irq_notify(cl, cb, cmpl_list); 542 if (ret) 543 return ret; 544 break; 545 case MEI_FOP_DMA_MAP: 546 ret = mei_cl_irq_dma_map(cl, cb, cmpl_list); 547 if (ret) 548 return ret; 549 break; 550 case MEI_FOP_DMA_UNMAP: 551 ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list); 552 if (ret) 553 return ret; 554 break; 555 default: 556 BUG(); 557 } 558 559 } 560 /* complete write list CB */ 561 dev_dbg(dev->dev, "complete write list cb.\n"); 562 list_for_each_entry_safe(cb, next, &dev->write_list, list) { 563 cl = cb->cl; 564 ret = mei_cl_irq_write(cl, cb, cmpl_list); 565 if (ret) 566 return ret; 567 } 568 return 0; 569 } 570 EXPORT_SYMBOL_GPL(mei_irq_write_handler); 571 572 573 /** 574 * mei_connect_timeout - connect/disconnect timeouts 575 * 576 * @cl: host client 577 */ 578 static void mei_connect_timeout(struct mei_cl *cl) 579 { 580 struct mei_device *dev = cl->dev; 581 582 if (cl->state == MEI_FILE_CONNECTING) { 583 if (dev->hbm_f_dot_supported) { 584 cl->state = MEI_FILE_DISCONNECT_REQUIRED; 585 wake_up(&cl->wait); 586 return; 587 } 588 } 589 mei_reset(dev); 590 } 591 592 #define MEI_STALL_TIMER_FREQ (2 * HZ) 593 /** 594 * mei_schedule_stall_timer - re-arm stall_timer work 595 * 596 * Schedule stall timer 597 * 598 * @dev: the device structure 599 */ 600 void mei_schedule_stall_timer(struct mei_device *dev) 601 { 602 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ); 603 } 604 605 /** 606 * mei_timer - timer function. 607 * 608 * @work: pointer to the work_struct structure 609 * 610 */ 611 void mei_timer(struct work_struct *work) 612 { 613 struct mei_cl *cl; 614 struct mei_device *dev = container_of(work, 615 struct mei_device, timer_work.work); 616 bool reschedule_timer = false; 617 618 mutex_lock(&dev->device_lock); 619 620 /* Catch interrupt stalls during HBM init handshake */ 621 if (dev->dev_state == MEI_DEV_INIT_CLIENTS && 622 dev->hbm_state != MEI_HBM_IDLE) { 623 624 if (dev->init_clients_timer) { 625 if (--dev->init_clients_timer == 0) { 626 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n", 627 dev->hbm_state); 628 mei_reset(dev); 629 goto out; 630 } 631 reschedule_timer = true; 632 } 633 } 634 635 if (dev->dev_state != MEI_DEV_ENABLED) 636 goto out; 637 638 /*** connect/disconnect timeouts ***/ 639 list_for_each_entry(cl, &dev->file_list, link) { 640 if (cl->timer_count) { 641 if (--cl->timer_count == 0) { 642 dev_err(dev->dev, "timer: connect/disconnect timeout.\n"); 643 mei_connect_timeout(cl); 644 goto out; 645 } 646 reschedule_timer = true; 647 } 648 } 649 650 out: 651 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer) 652 mei_schedule_stall_timer(dev); 653 654 mutex_unlock(&dev->device_lock); 655 } 656