1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Virtio driver for the paravirtualized IOMMU 4 * 5 * Copyright (C) 2019 Arm Limited 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/delay.h> 11 #include <linux/dma-map-ops.h> 12 #include <linux/freezer.h> 13 #include <linux/interval_tree.h> 14 #include <linux/iommu.h> 15 #include <linux/module.h> 16 #include <linux/of_platform.h> 17 #include <linux/pci.h> 18 #include <linux/virtio.h> 19 #include <linux/virtio_config.h> 20 #include <linux/virtio_ids.h> 21 #include <linux/wait.h> 22 23 #include <uapi/linux/virtio_iommu.h> 24 25 #include "dma-iommu.h" 26 27 #define MSI_IOVA_BASE 0x8000000 28 #define MSI_IOVA_LENGTH 0x100000 29 30 #define VIOMMU_REQUEST_VQ 0 31 #define VIOMMU_EVENT_VQ 1 32 #define VIOMMU_NR_VQS 2 33 34 struct viommu_dev { 35 struct iommu_device iommu; 36 struct device *dev; 37 struct virtio_device *vdev; 38 39 struct ida domain_ids; 40 41 struct virtqueue *vqs[VIOMMU_NR_VQS]; 42 spinlock_t request_lock; 43 struct list_head requests; 44 void *evts; 45 46 /* Device configuration */ 47 struct iommu_domain_geometry geometry; 48 u64 pgsize_bitmap; 49 u32 first_domain; 50 u32 last_domain; 51 /* Supported MAP flags */ 52 u32 map_flags; 53 u32 probe_size; 54 }; 55 56 struct viommu_mapping { 57 phys_addr_t paddr; 58 struct interval_tree_node iova; 59 u32 flags; 60 }; 61 62 struct viommu_domain { 63 struct iommu_domain domain; 64 struct viommu_dev *viommu; 65 struct mutex mutex; /* protects viommu pointer */ 66 unsigned int id; 67 u32 map_flags; 68 69 spinlock_t mappings_lock; 70 struct rb_root_cached mappings; 71 72 unsigned long nr_endpoints; 73 bool bypass; 74 }; 75 76 struct viommu_endpoint { 77 struct device *dev; 78 struct viommu_dev *viommu; 79 struct viommu_domain *vdomain; 80 struct list_head resv_regions; 81 }; 82 83 struct viommu_request { 84 struct list_head list; 85 void *writeback; 86 unsigned int write_offset; 87 unsigned int len; 88 char buf[]; 89 }; 90 91 #define VIOMMU_FAULT_RESV_MASK 0xffffff00 92 93 struct viommu_event { 94 union { 95 u32 head; 96 struct virtio_iommu_fault fault; 97 }; 98 }; 99 100 #define to_viommu_domain(domain) \ 101 container_of(domain, struct viommu_domain, domain) 102 103 static int viommu_get_req_errno(void *buf, size_t len) 104 { 105 struct virtio_iommu_req_tail *tail = buf + len - sizeof(*tail); 106 107 switch (tail->status) { 108 case VIRTIO_IOMMU_S_OK: 109 return 0; 110 case VIRTIO_IOMMU_S_UNSUPP: 111 return -ENOSYS; 112 case VIRTIO_IOMMU_S_INVAL: 113 return -EINVAL; 114 case VIRTIO_IOMMU_S_RANGE: 115 return -ERANGE; 116 case VIRTIO_IOMMU_S_NOENT: 117 return -ENOENT; 118 case VIRTIO_IOMMU_S_FAULT: 119 return -EFAULT; 120 case VIRTIO_IOMMU_S_NOMEM: 121 return -ENOMEM; 122 case VIRTIO_IOMMU_S_IOERR: 123 case VIRTIO_IOMMU_S_DEVERR: 124 default: 125 return -EIO; 126 } 127 } 128 129 static void viommu_set_req_status(void *buf, size_t len, int status) 130 { 131 struct virtio_iommu_req_tail *tail = buf + len - sizeof(*tail); 132 133 tail->status = status; 134 } 135 136 static off_t viommu_get_write_desc_offset(struct viommu_dev *viommu, 137 struct virtio_iommu_req_head *req, 138 size_t len) 139 { 140 size_t tail_size = sizeof(struct virtio_iommu_req_tail); 141 142 if (req->type == VIRTIO_IOMMU_T_PROBE) 143 return len - viommu->probe_size - tail_size; 144 145 return len - tail_size; 146 } 147 148 /* 149 * __viommu_sync_req - Complete all in-flight requests 150 * 151 * Wait for all added requests to complete. When this function returns, all 152 * requests that were in-flight at the time of the call have completed. 153 */ 154 static int __viommu_sync_req(struct viommu_dev *viommu) 155 { 156 unsigned int len; 157 size_t write_len; 158 struct viommu_request *req; 159 struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; 160 161 assert_spin_locked(&viommu->request_lock); 162 163 virtqueue_kick(vq); 164 165 while (!list_empty(&viommu->requests)) { 166 len = 0; 167 req = virtqueue_get_buf(vq, &len); 168 if (!req) 169 continue; 170 171 if (!len) 172 viommu_set_req_status(req->buf, req->len, 173 VIRTIO_IOMMU_S_IOERR); 174 175 write_len = req->len - req->write_offset; 176 if (req->writeback && len == write_len) 177 memcpy(req->writeback, req->buf + req->write_offset, 178 write_len); 179 180 list_del(&req->list); 181 kfree(req); 182 } 183 184 return 0; 185 } 186 187 static int viommu_sync_req(struct viommu_dev *viommu) 188 { 189 int ret; 190 unsigned long flags; 191 192 spin_lock_irqsave(&viommu->request_lock, flags); 193 ret = __viommu_sync_req(viommu); 194 if (ret) 195 dev_dbg(viommu->dev, "could not sync requests (%d)\n", ret); 196 spin_unlock_irqrestore(&viommu->request_lock, flags); 197 198 return ret; 199 } 200 201 /* 202 * __viommu_add_request - Add one request to the queue 203 * @buf: pointer to the request buffer 204 * @len: length of the request buffer 205 * @writeback: copy data back to the buffer when the request completes. 206 * 207 * Add a request to the queue. Only synchronize the queue if it's already full. 208 * Otherwise don't kick the queue nor wait for requests to complete. 209 * 210 * When @writeback is true, data written by the device, including the request 211 * status, is copied into @buf after the request completes. This is unsafe if 212 * the caller allocates @buf on stack and drops the lock between add_req() and 213 * sync_req(). 214 * 215 * Return 0 if the request was successfully added to the queue. 216 */ 217 static int __viommu_add_req(struct viommu_dev *viommu, void *buf, size_t len, 218 bool writeback) 219 { 220 int ret; 221 off_t write_offset; 222 struct viommu_request *req; 223 struct scatterlist top_sg, bottom_sg; 224 struct scatterlist *sg[2] = { &top_sg, &bottom_sg }; 225 struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; 226 227 assert_spin_locked(&viommu->request_lock); 228 229 write_offset = viommu_get_write_desc_offset(viommu, buf, len); 230 if (write_offset <= 0) 231 return -EINVAL; 232 233 req = kzalloc(sizeof(*req) + len, GFP_ATOMIC); 234 if (!req) 235 return -ENOMEM; 236 237 req->len = len; 238 if (writeback) { 239 req->writeback = buf + write_offset; 240 req->write_offset = write_offset; 241 } 242 memcpy(&req->buf, buf, write_offset); 243 244 sg_init_one(&top_sg, req->buf, write_offset); 245 sg_init_one(&bottom_sg, req->buf + write_offset, len - write_offset); 246 247 ret = virtqueue_add_sgs(vq, sg, 1, 1, req, GFP_ATOMIC); 248 if (ret == -ENOSPC) { 249 /* If the queue is full, sync and retry */ 250 if (!__viommu_sync_req(viommu)) 251 ret = virtqueue_add_sgs(vq, sg, 1, 1, req, GFP_ATOMIC); 252 } 253 if (ret) 254 goto err_free; 255 256 list_add_tail(&req->list, &viommu->requests); 257 return 0; 258 259 err_free: 260 kfree(req); 261 return ret; 262 } 263 264 static int viommu_add_req(struct viommu_dev *viommu, void *buf, size_t len) 265 { 266 int ret; 267 unsigned long flags; 268 269 spin_lock_irqsave(&viommu->request_lock, flags); 270 ret = __viommu_add_req(viommu, buf, len, false); 271 if (ret) 272 dev_dbg(viommu->dev, "could not add request: %d\n", ret); 273 spin_unlock_irqrestore(&viommu->request_lock, flags); 274 275 return ret; 276 } 277 278 /* 279 * Send a request and wait for it to complete. Return the request status (as an 280 * errno) 281 */ 282 static int viommu_send_req_sync(struct viommu_dev *viommu, void *buf, 283 size_t len) 284 { 285 int ret; 286 unsigned long flags; 287 288 spin_lock_irqsave(&viommu->request_lock, flags); 289 290 ret = __viommu_add_req(viommu, buf, len, true); 291 if (ret) { 292 dev_dbg(viommu->dev, "could not add request (%d)\n", ret); 293 goto out_unlock; 294 } 295 296 ret = __viommu_sync_req(viommu); 297 if (ret) { 298 dev_dbg(viommu->dev, "could not sync requests (%d)\n", ret); 299 /* Fall-through (get the actual request status) */ 300 } 301 302 ret = viommu_get_req_errno(buf, len); 303 out_unlock: 304 spin_unlock_irqrestore(&viommu->request_lock, flags); 305 return ret; 306 } 307 308 /* 309 * viommu_add_mapping - add a mapping to the internal tree 310 * 311 * On success, return the new mapping. Otherwise return NULL. 312 */ 313 static int viommu_add_mapping(struct viommu_domain *vdomain, u64 iova, u64 end, 314 phys_addr_t paddr, u32 flags) 315 { 316 unsigned long irqflags; 317 struct viommu_mapping *mapping; 318 319 mapping = kzalloc(sizeof(*mapping), GFP_ATOMIC); 320 if (!mapping) 321 return -ENOMEM; 322 323 mapping->paddr = paddr; 324 mapping->iova.start = iova; 325 mapping->iova.last = end; 326 mapping->flags = flags; 327 328 spin_lock_irqsave(&vdomain->mappings_lock, irqflags); 329 interval_tree_insert(&mapping->iova, &vdomain->mappings); 330 spin_unlock_irqrestore(&vdomain->mappings_lock, irqflags); 331 332 return 0; 333 } 334 335 /* 336 * viommu_del_mappings - remove mappings from the internal tree 337 * 338 * @vdomain: the domain 339 * @iova: start of the range 340 * @end: end of the range 341 * 342 * On success, returns the number of unmapped bytes 343 */ 344 static size_t viommu_del_mappings(struct viommu_domain *vdomain, 345 u64 iova, u64 end) 346 { 347 size_t unmapped = 0; 348 unsigned long flags; 349 struct viommu_mapping *mapping = NULL; 350 struct interval_tree_node *node, *next; 351 352 spin_lock_irqsave(&vdomain->mappings_lock, flags); 353 next = interval_tree_iter_first(&vdomain->mappings, iova, end); 354 while (next) { 355 node = next; 356 mapping = container_of(node, struct viommu_mapping, iova); 357 next = interval_tree_iter_next(node, iova, end); 358 359 /* Trying to split a mapping? */ 360 if (mapping->iova.start < iova) 361 break; 362 363 /* 364 * Virtio-iommu doesn't allow UNMAP to split a mapping created 365 * with a single MAP request, so remove the full mapping. 366 */ 367 unmapped += mapping->iova.last - mapping->iova.start + 1; 368 369 interval_tree_remove(node, &vdomain->mappings); 370 kfree(mapping); 371 } 372 spin_unlock_irqrestore(&vdomain->mappings_lock, flags); 373 374 return unmapped; 375 } 376 377 /* 378 * Fill the domain with identity mappings, skipping the device's reserved 379 * regions. 380 */ 381 static int viommu_domain_map_identity(struct viommu_endpoint *vdev, 382 struct viommu_domain *vdomain) 383 { 384 int ret; 385 struct iommu_resv_region *resv; 386 u64 iova = vdomain->domain.geometry.aperture_start; 387 u64 limit = vdomain->domain.geometry.aperture_end; 388 u32 flags = VIRTIO_IOMMU_MAP_F_READ | VIRTIO_IOMMU_MAP_F_WRITE; 389 unsigned long granule = 1UL << __ffs(vdomain->domain.pgsize_bitmap); 390 391 iova = ALIGN(iova, granule); 392 limit = ALIGN_DOWN(limit + 1, granule) - 1; 393 394 list_for_each_entry(resv, &vdev->resv_regions, list) { 395 u64 resv_start = ALIGN_DOWN(resv->start, granule); 396 u64 resv_end = ALIGN(resv->start + resv->length, granule) - 1; 397 398 if (resv_end < iova || resv_start > limit) 399 /* No overlap */ 400 continue; 401 402 if (resv_start > iova) { 403 ret = viommu_add_mapping(vdomain, iova, resv_start - 1, 404 (phys_addr_t)iova, flags); 405 if (ret) 406 goto err_unmap; 407 } 408 409 if (resv_end >= limit) 410 return 0; 411 412 iova = resv_end + 1; 413 } 414 415 ret = viommu_add_mapping(vdomain, iova, limit, (phys_addr_t)iova, 416 flags); 417 if (ret) 418 goto err_unmap; 419 return 0; 420 421 err_unmap: 422 viommu_del_mappings(vdomain, 0, iova); 423 return ret; 424 } 425 426 /* 427 * viommu_replay_mappings - re-send MAP requests 428 * 429 * When reattaching a domain that was previously detached from all endpoints, 430 * mappings were deleted from the device. Re-create the mappings available in 431 * the internal tree. 432 */ 433 static int viommu_replay_mappings(struct viommu_domain *vdomain) 434 { 435 int ret = 0; 436 unsigned long flags; 437 struct viommu_mapping *mapping; 438 struct interval_tree_node *node; 439 struct virtio_iommu_req_map map; 440 441 spin_lock_irqsave(&vdomain->mappings_lock, flags); 442 node = interval_tree_iter_first(&vdomain->mappings, 0, -1UL); 443 while (node) { 444 mapping = container_of(node, struct viommu_mapping, iova); 445 map = (struct virtio_iommu_req_map) { 446 .head.type = VIRTIO_IOMMU_T_MAP, 447 .domain = cpu_to_le32(vdomain->id), 448 .virt_start = cpu_to_le64(mapping->iova.start), 449 .virt_end = cpu_to_le64(mapping->iova.last), 450 .phys_start = cpu_to_le64(mapping->paddr), 451 .flags = cpu_to_le32(mapping->flags), 452 }; 453 454 ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map)); 455 if (ret) 456 break; 457 458 node = interval_tree_iter_next(node, 0, -1UL); 459 } 460 spin_unlock_irqrestore(&vdomain->mappings_lock, flags); 461 462 return ret; 463 } 464 465 static int viommu_add_resv_mem(struct viommu_endpoint *vdev, 466 struct virtio_iommu_probe_resv_mem *mem, 467 size_t len) 468 { 469 size_t size; 470 u64 start64, end64; 471 phys_addr_t start, end; 472 struct iommu_resv_region *region = NULL, *next; 473 unsigned long prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; 474 475 start = start64 = le64_to_cpu(mem->start); 476 end = end64 = le64_to_cpu(mem->end); 477 size = end64 - start64 + 1; 478 479 /* Catch any overflow, including the unlikely end64 - start64 + 1 = 0 */ 480 if (start != start64 || end != end64 || size < end64 - start64) 481 return -EOVERFLOW; 482 483 if (len < sizeof(*mem)) 484 return -EINVAL; 485 486 switch (mem->subtype) { 487 default: 488 dev_warn(vdev->dev, "unknown resv mem subtype 0x%x\n", 489 mem->subtype); 490 fallthrough; 491 case VIRTIO_IOMMU_RESV_MEM_T_RESERVED: 492 region = iommu_alloc_resv_region(start, size, 0, 493 IOMMU_RESV_RESERVED); 494 break; 495 case VIRTIO_IOMMU_RESV_MEM_T_MSI: 496 region = iommu_alloc_resv_region(start, size, prot, 497 IOMMU_RESV_MSI); 498 break; 499 } 500 if (!region) 501 return -ENOMEM; 502 503 /* Keep the list sorted */ 504 list_for_each_entry(next, &vdev->resv_regions, list) { 505 if (next->start > region->start) 506 break; 507 } 508 list_add_tail(®ion->list, &next->list); 509 return 0; 510 } 511 512 static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev) 513 { 514 int ret; 515 u16 type, len; 516 size_t cur = 0; 517 size_t probe_len; 518 struct virtio_iommu_req_probe *probe; 519 struct virtio_iommu_probe_property *prop; 520 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); 521 struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); 522 523 if (!fwspec->num_ids) 524 return -EINVAL; 525 526 probe_len = sizeof(*probe) + viommu->probe_size + 527 sizeof(struct virtio_iommu_req_tail); 528 probe = kzalloc(probe_len, GFP_KERNEL); 529 if (!probe) 530 return -ENOMEM; 531 532 probe->head.type = VIRTIO_IOMMU_T_PROBE; 533 /* 534 * For now, assume that properties of an endpoint that outputs multiple 535 * IDs are consistent. Only probe the first one. 536 */ 537 probe->endpoint = cpu_to_le32(fwspec->ids[0]); 538 539 ret = viommu_send_req_sync(viommu, probe, probe_len); 540 if (ret) 541 goto out_free; 542 543 prop = (void *)probe->properties; 544 type = le16_to_cpu(prop->type) & VIRTIO_IOMMU_PROBE_T_MASK; 545 546 while (type != VIRTIO_IOMMU_PROBE_T_NONE && 547 cur < viommu->probe_size) { 548 len = le16_to_cpu(prop->length) + sizeof(*prop); 549 550 switch (type) { 551 case VIRTIO_IOMMU_PROBE_T_RESV_MEM: 552 ret = viommu_add_resv_mem(vdev, (void *)prop, len); 553 break; 554 default: 555 dev_err(dev, "unknown viommu prop 0x%x\n", type); 556 } 557 558 if (ret) 559 dev_err(dev, "failed to parse viommu prop 0x%x\n", type); 560 561 cur += len; 562 if (cur >= viommu->probe_size) 563 break; 564 565 prop = (void *)probe->properties + cur; 566 type = le16_to_cpu(prop->type) & VIRTIO_IOMMU_PROBE_T_MASK; 567 } 568 569 out_free: 570 kfree(probe); 571 return ret; 572 } 573 574 static int viommu_fault_handler(struct viommu_dev *viommu, 575 struct virtio_iommu_fault *fault) 576 { 577 char *reason_str; 578 579 u8 reason = fault->reason; 580 u32 flags = le32_to_cpu(fault->flags); 581 u32 endpoint = le32_to_cpu(fault->endpoint); 582 u64 address = le64_to_cpu(fault->address); 583 584 switch (reason) { 585 case VIRTIO_IOMMU_FAULT_R_DOMAIN: 586 reason_str = "domain"; 587 break; 588 case VIRTIO_IOMMU_FAULT_R_MAPPING: 589 reason_str = "page"; 590 break; 591 case VIRTIO_IOMMU_FAULT_R_UNKNOWN: 592 default: 593 reason_str = "unknown"; 594 break; 595 } 596 597 /* TODO: find EP by ID and report_iommu_fault */ 598 if (flags & VIRTIO_IOMMU_FAULT_F_ADDRESS) 599 dev_err_ratelimited(viommu->dev, "%s fault from EP %u at %#llx [%s%s%s]\n", 600 reason_str, endpoint, address, 601 flags & VIRTIO_IOMMU_FAULT_F_READ ? "R" : "", 602 flags & VIRTIO_IOMMU_FAULT_F_WRITE ? "W" : "", 603 flags & VIRTIO_IOMMU_FAULT_F_EXEC ? "X" : ""); 604 else 605 dev_err_ratelimited(viommu->dev, "%s fault from EP %u\n", 606 reason_str, endpoint); 607 return 0; 608 } 609 610 static void viommu_event_handler(struct virtqueue *vq) 611 { 612 int ret; 613 unsigned int len; 614 struct scatterlist sg[1]; 615 struct viommu_event *evt; 616 struct viommu_dev *viommu = vq->vdev->priv; 617 618 while ((evt = virtqueue_get_buf(vq, &len)) != NULL) { 619 if (len > sizeof(*evt)) { 620 dev_err(viommu->dev, 621 "invalid event buffer (len %u != %zu)\n", 622 len, sizeof(*evt)); 623 } else if (!(evt->head & VIOMMU_FAULT_RESV_MASK)) { 624 viommu_fault_handler(viommu, &evt->fault); 625 } 626 627 sg_init_one(sg, evt, sizeof(*evt)); 628 ret = virtqueue_add_inbuf(vq, sg, 1, evt, GFP_ATOMIC); 629 if (ret) 630 dev_err(viommu->dev, "could not add event buffer\n"); 631 } 632 633 virtqueue_kick(vq); 634 } 635 636 /* IOMMU API */ 637 638 static struct iommu_domain *viommu_domain_alloc(unsigned type) 639 { 640 struct viommu_domain *vdomain; 641 642 if (type != IOMMU_DOMAIN_UNMANAGED && 643 type != IOMMU_DOMAIN_DMA && 644 type != IOMMU_DOMAIN_IDENTITY) 645 return NULL; 646 647 vdomain = kzalloc(sizeof(*vdomain), GFP_KERNEL); 648 if (!vdomain) 649 return NULL; 650 651 mutex_init(&vdomain->mutex); 652 spin_lock_init(&vdomain->mappings_lock); 653 vdomain->mappings = RB_ROOT_CACHED; 654 655 return &vdomain->domain; 656 } 657 658 static int viommu_domain_finalise(struct viommu_endpoint *vdev, 659 struct iommu_domain *domain) 660 { 661 int ret; 662 unsigned long viommu_page_size; 663 struct viommu_dev *viommu = vdev->viommu; 664 struct viommu_domain *vdomain = to_viommu_domain(domain); 665 666 viommu_page_size = 1UL << __ffs(viommu->pgsize_bitmap); 667 if (viommu_page_size > PAGE_SIZE) { 668 dev_err(vdev->dev, 669 "granule 0x%lx larger than system page size 0x%lx\n", 670 viommu_page_size, PAGE_SIZE); 671 return -EINVAL; 672 } 673 674 ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, 675 viommu->last_domain, GFP_KERNEL); 676 if (ret < 0) 677 return ret; 678 679 vdomain->id = (unsigned int)ret; 680 681 domain->pgsize_bitmap = viommu->pgsize_bitmap; 682 domain->geometry = viommu->geometry; 683 684 vdomain->map_flags = viommu->map_flags; 685 vdomain->viommu = viommu; 686 687 if (domain->type == IOMMU_DOMAIN_IDENTITY) { 688 if (virtio_has_feature(viommu->vdev, 689 VIRTIO_IOMMU_F_BYPASS_CONFIG)) { 690 vdomain->bypass = true; 691 return 0; 692 } 693 694 ret = viommu_domain_map_identity(vdev, vdomain); 695 if (ret) { 696 ida_free(&viommu->domain_ids, vdomain->id); 697 vdomain->viommu = NULL; 698 return -EOPNOTSUPP; 699 } 700 } 701 702 return 0; 703 } 704 705 static void viommu_domain_free(struct iommu_domain *domain) 706 { 707 struct viommu_domain *vdomain = to_viommu_domain(domain); 708 709 /* Free all remaining mappings */ 710 viommu_del_mappings(vdomain, 0, ULLONG_MAX); 711 712 if (vdomain->viommu) 713 ida_free(&vdomain->viommu->domain_ids, vdomain->id); 714 715 kfree(vdomain); 716 } 717 718 static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) 719 { 720 int i; 721 int ret = 0; 722 struct virtio_iommu_req_attach req; 723 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); 724 struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); 725 struct viommu_domain *vdomain = to_viommu_domain(domain); 726 727 mutex_lock(&vdomain->mutex); 728 if (!vdomain->viommu) { 729 /* 730 * Properly initialize the domain now that we know which viommu 731 * owns it. 732 */ 733 ret = viommu_domain_finalise(vdev, domain); 734 } else if (vdomain->viommu != vdev->viommu) { 735 dev_err(dev, "cannot attach to foreign vIOMMU\n"); 736 ret = -EXDEV; 737 } 738 mutex_unlock(&vdomain->mutex); 739 740 if (ret) 741 return ret; 742 743 /* 744 * In the virtio-iommu device, when attaching the endpoint to a new 745 * domain, it is detached from the old one and, if as a result the 746 * old domain isn't attached to any endpoint, all mappings are removed 747 * from the old domain and it is freed. 748 * 749 * In the driver the old domain still exists, and its mappings will be 750 * recreated if it gets reattached to an endpoint. Otherwise it will be 751 * freed explicitly. 752 * 753 * vdev->vdomain is protected by group->mutex 754 */ 755 if (vdev->vdomain) 756 vdev->vdomain->nr_endpoints--; 757 758 req = (struct virtio_iommu_req_attach) { 759 .head.type = VIRTIO_IOMMU_T_ATTACH, 760 .domain = cpu_to_le32(vdomain->id), 761 }; 762 763 if (vdomain->bypass) 764 req.flags |= cpu_to_le32(VIRTIO_IOMMU_ATTACH_F_BYPASS); 765 766 for (i = 0; i < fwspec->num_ids; i++) { 767 req.endpoint = cpu_to_le32(fwspec->ids[i]); 768 769 ret = viommu_send_req_sync(vdomain->viommu, &req, sizeof(req)); 770 if (ret) 771 return ret; 772 } 773 774 if (!vdomain->nr_endpoints) { 775 /* 776 * This endpoint is the first to be attached to the domain. 777 * Replay existing mappings (e.g. SW MSI). 778 */ 779 ret = viommu_replay_mappings(vdomain); 780 if (ret) 781 return ret; 782 } 783 784 vdomain->nr_endpoints++; 785 vdev->vdomain = vdomain; 786 787 return 0; 788 } 789 790 static int viommu_map_pages(struct iommu_domain *domain, unsigned long iova, 791 phys_addr_t paddr, size_t pgsize, size_t pgcount, 792 int prot, gfp_t gfp, size_t *mapped) 793 { 794 int ret; 795 u32 flags; 796 size_t size = pgsize * pgcount; 797 u64 end = iova + size - 1; 798 struct virtio_iommu_req_map map; 799 struct viommu_domain *vdomain = to_viommu_domain(domain); 800 801 flags = (prot & IOMMU_READ ? VIRTIO_IOMMU_MAP_F_READ : 0) | 802 (prot & IOMMU_WRITE ? VIRTIO_IOMMU_MAP_F_WRITE : 0) | 803 (prot & IOMMU_MMIO ? VIRTIO_IOMMU_MAP_F_MMIO : 0); 804 805 if (flags & ~vdomain->map_flags) 806 return -EINVAL; 807 808 ret = viommu_add_mapping(vdomain, iova, end, paddr, flags); 809 if (ret) 810 return ret; 811 812 map = (struct virtio_iommu_req_map) { 813 .head.type = VIRTIO_IOMMU_T_MAP, 814 .domain = cpu_to_le32(vdomain->id), 815 .virt_start = cpu_to_le64(iova), 816 .phys_start = cpu_to_le64(paddr), 817 .virt_end = cpu_to_le64(end), 818 .flags = cpu_to_le32(flags), 819 }; 820 821 if (!vdomain->nr_endpoints) 822 return 0; 823 824 ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map)); 825 if (ret) 826 viommu_del_mappings(vdomain, iova, end); 827 else if (mapped) 828 *mapped = size; 829 830 return ret; 831 } 832 833 static size_t viommu_unmap_pages(struct iommu_domain *domain, unsigned long iova, 834 size_t pgsize, size_t pgcount, 835 struct iommu_iotlb_gather *gather) 836 { 837 int ret = 0; 838 size_t unmapped; 839 struct virtio_iommu_req_unmap unmap; 840 struct viommu_domain *vdomain = to_viommu_domain(domain); 841 size_t size = pgsize * pgcount; 842 843 unmapped = viommu_del_mappings(vdomain, iova, iova + size - 1); 844 if (unmapped < size) 845 return 0; 846 847 /* Device already removed all mappings after detach. */ 848 if (!vdomain->nr_endpoints) 849 return unmapped; 850 851 unmap = (struct virtio_iommu_req_unmap) { 852 .head.type = VIRTIO_IOMMU_T_UNMAP, 853 .domain = cpu_to_le32(vdomain->id), 854 .virt_start = cpu_to_le64(iova), 855 .virt_end = cpu_to_le64(iova + unmapped - 1), 856 }; 857 858 ret = viommu_add_req(vdomain->viommu, &unmap, sizeof(unmap)); 859 return ret ? 0 : unmapped; 860 } 861 862 static phys_addr_t viommu_iova_to_phys(struct iommu_domain *domain, 863 dma_addr_t iova) 864 { 865 u64 paddr = 0; 866 unsigned long flags; 867 struct viommu_mapping *mapping; 868 struct interval_tree_node *node; 869 struct viommu_domain *vdomain = to_viommu_domain(domain); 870 871 spin_lock_irqsave(&vdomain->mappings_lock, flags); 872 node = interval_tree_iter_first(&vdomain->mappings, iova, iova); 873 if (node) { 874 mapping = container_of(node, struct viommu_mapping, iova); 875 paddr = mapping->paddr + (iova - mapping->iova.start); 876 } 877 spin_unlock_irqrestore(&vdomain->mappings_lock, flags); 878 879 return paddr; 880 } 881 882 static void viommu_iotlb_sync(struct iommu_domain *domain, 883 struct iommu_iotlb_gather *gather) 884 { 885 struct viommu_domain *vdomain = to_viommu_domain(domain); 886 887 viommu_sync_req(vdomain->viommu); 888 } 889 890 static void viommu_get_resv_regions(struct device *dev, struct list_head *head) 891 { 892 struct iommu_resv_region *entry, *new_entry, *msi = NULL; 893 struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); 894 int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; 895 896 list_for_each_entry(entry, &vdev->resv_regions, list) { 897 if (entry->type == IOMMU_RESV_MSI) 898 msi = entry; 899 900 new_entry = kmemdup(entry, sizeof(*entry), GFP_KERNEL); 901 if (!new_entry) 902 return; 903 list_add_tail(&new_entry->list, head); 904 } 905 906 /* 907 * If the device didn't register any bypass MSI window, add a 908 * software-mapped region. 909 */ 910 if (!msi) { 911 msi = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH, 912 prot, IOMMU_RESV_SW_MSI); 913 if (!msi) 914 return; 915 916 list_add_tail(&msi->list, head); 917 } 918 919 iommu_dma_get_resv_regions(dev, head); 920 } 921 922 static struct iommu_ops viommu_ops; 923 static struct virtio_driver virtio_iommu_drv; 924 925 static int viommu_match_node(struct device *dev, const void *data) 926 { 927 return device_match_fwnode(dev->parent, data); 928 } 929 930 static struct viommu_dev *viommu_get_by_fwnode(struct fwnode_handle *fwnode) 931 { 932 struct device *dev = driver_find_device(&virtio_iommu_drv.driver, NULL, 933 fwnode, viommu_match_node); 934 put_device(dev); 935 936 return dev ? dev_to_virtio(dev)->priv : NULL; 937 } 938 939 static struct iommu_device *viommu_probe_device(struct device *dev) 940 { 941 int ret; 942 struct viommu_endpoint *vdev; 943 struct viommu_dev *viommu = NULL; 944 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); 945 946 if (!fwspec || fwspec->ops != &viommu_ops) 947 return ERR_PTR(-ENODEV); 948 949 viommu = viommu_get_by_fwnode(fwspec->iommu_fwnode); 950 if (!viommu) 951 return ERR_PTR(-ENODEV); 952 953 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); 954 if (!vdev) 955 return ERR_PTR(-ENOMEM); 956 957 vdev->dev = dev; 958 vdev->viommu = viommu; 959 INIT_LIST_HEAD(&vdev->resv_regions); 960 dev_iommu_priv_set(dev, vdev); 961 962 if (viommu->probe_size) { 963 /* Get additional information for this endpoint */ 964 ret = viommu_probe_endpoint(viommu, dev); 965 if (ret) 966 goto err_free_dev; 967 } 968 969 return &viommu->iommu; 970 971 err_free_dev: 972 iommu_put_resv_regions(dev, &vdev->resv_regions); 973 kfree(vdev); 974 975 return ERR_PTR(ret); 976 } 977 978 static void viommu_probe_finalize(struct device *dev) 979 { 980 #ifndef CONFIG_ARCH_HAS_SETUP_DMA_OPS 981 /* First clear the DMA ops in case we're switching from a DMA domain */ 982 set_dma_ops(dev, NULL); 983 iommu_setup_dma_ops(dev, 0, U64_MAX); 984 #endif 985 } 986 987 static void viommu_release_device(struct device *dev) 988 { 989 struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); 990 991 iommu_put_resv_regions(dev, &vdev->resv_regions); 992 kfree(vdev); 993 } 994 995 static struct iommu_group *viommu_device_group(struct device *dev) 996 { 997 if (dev_is_pci(dev)) 998 return pci_device_group(dev); 999 else 1000 return generic_device_group(dev); 1001 } 1002 1003 static int viommu_of_xlate(struct device *dev, struct of_phandle_args *args) 1004 { 1005 return iommu_fwspec_add_ids(dev, args->args, 1); 1006 } 1007 1008 static bool viommu_capable(struct device *dev, enum iommu_cap cap) 1009 { 1010 switch (cap) { 1011 case IOMMU_CAP_CACHE_COHERENCY: 1012 return true; 1013 default: 1014 return false; 1015 } 1016 } 1017 1018 static struct iommu_ops viommu_ops = { 1019 .capable = viommu_capable, 1020 .domain_alloc = viommu_domain_alloc, 1021 .probe_device = viommu_probe_device, 1022 .probe_finalize = viommu_probe_finalize, 1023 .release_device = viommu_release_device, 1024 .device_group = viommu_device_group, 1025 .get_resv_regions = viommu_get_resv_regions, 1026 .of_xlate = viommu_of_xlate, 1027 .owner = THIS_MODULE, 1028 .default_domain_ops = &(const struct iommu_domain_ops) { 1029 .attach_dev = viommu_attach_dev, 1030 .map_pages = viommu_map_pages, 1031 .unmap_pages = viommu_unmap_pages, 1032 .iova_to_phys = viommu_iova_to_phys, 1033 .iotlb_sync = viommu_iotlb_sync, 1034 .free = viommu_domain_free, 1035 } 1036 }; 1037 1038 static int viommu_init_vqs(struct viommu_dev *viommu) 1039 { 1040 struct virtio_device *vdev = dev_to_virtio(viommu->dev); 1041 const char *names[] = { "request", "event" }; 1042 vq_callback_t *callbacks[] = { 1043 NULL, /* No async requests */ 1044 viommu_event_handler, 1045 }; 1046 1047 return virtio_find_vqs(vdev, VIOMMU_NR_VQS, viommu->vqs, callbacks, 1048 names, NULL); 1049 } 1050 1051 static int viommu_fill_evtq(struct viommu_dev *viommu) 1052 { 1053 int i, ret; 1054 struct scatterlist sg[1]; 1055 struct viommu_event *evts; 1056 struct virtqueue *vq = viommu->vqs[VIOMMU_EVENT_VQ]; 1057 size_t nr_evts = vq->num_free; 1058 1059 viommu->evts = evts = devm_kmalloc_array(viommu->dev, nr_evts, 1060 sizeof(*evts), GFP_KERNEL); 1061 if (!evts) 1062 return -ENOMEM; 1063 1064 for (i = 0; i < nr_evts; i++) { 1065 sg_init_one(sg, &evts[i], sizeof(*evts)); 1066 ret = virtqueue_add_inbuf(vq, sg, 1, &evts[i], GFP_KERNEL); 1067 if (ret) 1068 return ret; 1069 } 1070 1071 return 0; 1072 } 1073 1074 static int viommu_probe(struct virtio_device *vdev) 1075 { 1076 struct device *parent_dev = vdev->dev.parent; 1077 struct viommu_dev *viommu = NULL; 1078 struct device *dev = &vdev->dev; 1079 u64 input_start = 0; 1080 u64 input_end = -1UL; 1081 int ret; 1082 1083 if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1) || 1084 !virtio_has_feature(vdev, VIRTIO_IOMMU_F_MAP_UNMAP)) 1085 return -ENODEV; 1086 1087 viommu = devm_kzalloc(dev, sizeof(*viommu), GFP_KERNEL); 1088 if (!viommu) 1089 return -ENOMEM; 1090 1091 spin_lock_init(&viommu->request_lock); 1092 ida_init(&viommu->domain_ids); 1093 viommu->dev = dev; 1094 viommu->vdev = vdev; 1095 INIT_LIST_HEAD(&viommu->requests); 1096 1097 ret = viommu_init_vqs(viommu); 1098 if (ret) 1099 return ret; 1100 1101 virtio_cread_le(vdev, struct virtio_iommu_config, page_size_mask, 1102 &viommu->pgsize_bitmap); 1103 1104 if (!viommu->pgsize_bitmap) { 1105 ret = -EINVAL; 1106 goto err_free_vqs; 1107 } 1108 1109 viommu->map_flags = VIRTIO_IOMMU_MAP_F_READ | VIRTIO_IOMMU_MAP_F_WRITE; 1110 viommu->last_domain = ~0U; 1111 1112 /* Optional features */ 1113 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, 1114 struct virtio_iommu_config, input_range.start, 1115 &input_start); 1116 1117 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, 1118 struct virtio_iommu_config, input_range.end, 1119 &input_end); 1120 1121 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE, 1122 struct virtio_iommu_config, domain_range.start, 1123 &viommu->first_domain); 1124 1125 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE, 1126 struct virtio_iommu_config, domain_range.end, 1127 &viommu->last_domain); 1128 1129 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_PROBE, 1130 struct virtio_iommu_config, probe_size, 1131 &viommu->probe_size); 1132 1133 viommu->geometry = (struct iommu_domain_geometry) { 1134 .aperture_start = input_start, 1135 .aperture_end = input_end, 1136 .force_aperture = true, 1137 }; 1138 1139 if (virtio_has_feature(vdev, VIRTIO_IOMMU_F_MMIO)) 1140 viommu->map_flags |= VIRTIO_IOMMU_MAP_F_MMIO; 1141 1142 viommu_ops.pgsize_bitmap = viommu->pgsize_bitmap; 1143 1144 virtio_device_ready(vdev); 1145 1146 /* Populate the event queue with buffers */ 1147 ret = viommu_fill_evtq(viommu); 1148 if (ret) 1149 goto err_free_vqs; 1150 1151 ret = iommu_device_sysfs_add(&viommu->iommu, dev, NULL, "%s", 1152 virtio_bus_name(vdev)); 1153 if (ret) 1154 goto err_free_vqs; 1155 1156 iommu_device_register(&viommu->iommu, &viommu_ops, parent_dev); 1157 1158 vdev->priv = viommu; 1159 1160 dev_info(dev, "input address: %u bits\n", 1161 order_base_2(viommu->geometry.aperture_end)); 1162 dev_info(dev, "page mask: %#llx\n", viommu->pgsize_bitmap); 1163 1164 return 0; 1165 1166 err_free_vqs: 1167 vdev->config->del_vqs(vdev); 1168 1169 return ret; 1170 } 1171 1172 static void viommu_remove(struct virtio_device *vdev) 1173 { 1174 struct viommu_dev *viommu = vdev->priv; 1175 1176 iommu_device_sysfs_remove(&viommu->iommu); 1177 iommu_device_unregister(&viommu->iommu); 1178 1179 /* Stop all virtqueues */ 1180 virtio_reset_device(vdev); 1181 vdev->config->del_vqs(vdev); 1182 1183 dev_info(&vdev->dev, "device removed\n"); 1184 } 1185 1186 static void viommu_config_changed(struct virtio_device *vdev) 1187 { 1188 dev_warn(&vdev->dev, "config changed\n"); 1189 } 1190 1191 static unsigned int features[] = { 1192 VIRTIO_IOMMU_F_MAP_UNMAP, 1193 VIRTIO_IOMMU_F_INPUT_RANGE, 1194 VIRTIO_IOMMU_F_DOMAIN_RANGE, 1195 VIRTIO_IOMMU_F_PROBE, 1196 VIRTIO_IOMMU_F_MMIO, 1197 VIRTIO_IOMMU_F_BYPASS_CONFIG, 1198 }; 1199 1200 static struct virtio_device_id id_table[] = { 1201 { VIRTIO_ID_IOMMU, VIRTIO_DEV_ANY_ID }, 1202 { 0 }, 1203 }; 1204 MODULE_DEVICE_TABLE(virtio, id_table); 1205 1206 static struct virtio_driver virtio_iommu_drv = { 1207 .driver.name = KBUILD_MODNAME, 1208 .driver.owner = THIS_MODULE, 1209 .id_table = id_table, 1210 .feature_table = features, 1211 .feature_table_size = ARRAY_SIZE(features), 1212 .probe = viommu_probe, 1213 .remove = viommu_remove, 1214 .config_changed = viommu_config_changed, 1215 }; 1216 1217 module_virtio_driver(virtio_iommu_drv); 1218 1219 MODULE_DESCRIPTION("Virtio IOMMU driver"); 1220 MODULE_AUTHOR("Jean-Philippe Brucker <jean-philippe.brucker@arm.com>"); 1221 MODULE_LICENSE("GPL v2"); 1222