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.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 34struct 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 56struct viommu_mapping { 57 phys_addr_t paddr; 58 struct interval_tree_node iova; 59 u32 flags; 60}; 61 62struct 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 76struct viommu_endpoint { 77 struct device *dev; 78 struct viommu_dev *viommu; 79 struct viommu_domain *vdomain; 80 struct list_head resv_regions; 81}; 82 83struct viommu_request { 84 struct list_head list; 85 void *writeback; 86 unsigned int write_offset; 87 unsigned int len; 88 char buf[] __counted_by(len); 89}; 90 91#define VIOMMU_FAULT_RESV_MASK 0xffffff00 92 93struct 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 103static 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 129static 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 136static 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 */ 154static 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 187static 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 */ 217static 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(struct_size(req, buf, 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 259err_free: 260 kfree(req); 261 return ret; 262} 263 264static 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 */ 282static 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); 303out_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 */ 313static 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 */ 344static 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 */ 381static 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 421err_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 */ 433static 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 465static 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 GFP_KERNEL); 495 break; 496 case VIRTIO_IOMMU_RESV_MEM_T_MSI: 497 region = iommu_alloc_resv_region(start, size, prot, 498 IOMMU_RESV_MSI, 499 GFP_KERNEL); 500 break; 501 } 502 if (!region) 503 return -ENOMEM; 504 505 /* Keep the list sorted */ 506 list_for_each_entry(next, &vdev->resv_regions, list) { 507 if (next->start > region->start) 508 break; 509 } 510 list_add_tail(®ion->list, &next->list); 511 return 0; 512} 513 514static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev) 515{ 516 int ret; 517 u16 type, len; 518 size_t cur = 0; 519 size_t probe_len; 520 struct virtio_iommu_req_probe *probe; 521 struct virtio_iommu_probe_property *prop; 522 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); 523 struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); 524 525 if (!fwspec->num_ids) 526 return -EINVAL; 527 528 probe_len = sizeof(*probe) + viommu->probe_size + 529 sizeof(struct virtio_iommu_req_tail); 530 probe = kzalloc(probe_len, GFP_KERNEL); 531 if (!probe) 532 return -ENOMEM; 533 534 probe->head.type = VIRTIO_IOMMU_T_PROBE; 535 /* 536 * For now, assume that properties of an endpoint that outputs multiple 537 * IDs are consistent. Only probe the first one. 538 */ 539 probe->endpoint = cpu_to_le32(fwspec->ids[0]); 540 541 ret = viommu_send_req_sync(viommu, probe, probe_len); 542 if (ret) 543 goto out_free; 544 545 prop = (void *)probe->properties; 546 type = le16_to_cpu(prop->type) & VIRTIO_IOMMU_PROBE_T_MASK; 547 548 while (type != VIRTIO_IOMMU_PROBE_T_NONE && 549 cur < viommu->probe_size) { 550 len = le16_to_cpu(prop->length) + sizeof(*prop); 551 552 switch (type) { 553 case VIRTIO_IOMMU_PROBE_T_RESV_MEM: 554 ret = viommu_add_resv_mem(vdev, (void *)prop, len); 555 break; 556 default: 557 dev_err(dev, "unknown viommu prop 0x%x\n", type); 558 } 559 560 if (ret) 561 dev_err(dev, "failed to parse viommu prop 0x%x\n", type); 562 563 cur += len; 564 if (cur >= viommu->probe_size) 565 break; 566 567 prop = (void *)probe->properties + cur; 568 type = le16_to_cpu(prop->type) & VIRTIO_IOMMU_PROBE_T_MASK; 569 } 570 571out_free: 572 kfree(probe); 573 return ret; 574} 575 576static int viommu_fault_handler(struct viommu_dev *viommu, 577 struct virtio_iommu_fault *fault) 578{ 579 char *reason_str; 580 581 u8 reason = fault->reason; 582 u32 flags = le32_to_cpu(fault->flags); 583 u32 endpoint = le32_to_cpu(fault->endpoint); 584 u64 address = le64_to_cpu(fault->address); 585 586 switch (reason) { 587 case VIRTIO_IOMMU_FAULT_R_DOMAIN: 588 reason_str = "domain"; 589 break; 590 case VIRTIO_IOMMU_FAULT_R_MAPPING: 591 reason_str = "page"; 592 break; 593 case VIRTIO_IOMMU_FAULT_R_UNKNOWN: 594 default: 595 reason_str = "unknown"; 596 break; 597 } 598 599 /* TODO: find EP by ID and report_iommu_fault */ 600 if (flags & VIRTIO_IOMMU_FAULT_F_ADDRESS) 601 dev_err_ratelimited(viommu->dev, "%s fault from EP %u at %#llx [%s%s%s]\n", 602 reason_str, endpoint, address, 603 flags & VIRTIO_IOMMU_FAULT_F_READ ? "R" : "", 604 flags & VIRTIO_IOMMU_FAULT_F_WRITE ? "W" : "", 605 flags & VIRTIO_IOMMU_FAULT_F_EXEC ? "X" : ""); 606 else 607 dev_err_ratelimited(viommu->dev, "%s fault from EP %u\n", 608 reason_str, endpoint); 609 return 0; 610} 611 612static void viommu_event_handler(struct virtqueue *vq) 613{ 614 int ret; 615 unsigned int len; 616 struct scatterlist sg[1]; 617 struct viommu_event *evt; 618 struct viommu_dev *viommu = vq->vdev->priv; 619 620 while ((evt = virtqueue_get_buf(vq, &len)) != NULL) { 621 if (len > sizeof(*evt)) { 622 dev_err(viommu->dev, 623 "invalid event buffer (len %u != %zu)\n", 624 len, sizeof(*evt)); 625 } else if (!(evt->head & VIOMMU_FAULT_RESV_MASK)) { 626 viommu_fault_handler(viommu, &evt->fault); 627 } 628 629 sg_init_one(sg, evt, sizeof(*evt)); 630 ret = virtqueue_add_inbuf(vq, sg, 1, evt, GFP_ATOMIC); 631 if (ret) 632 dev_err(viommu->dev, "could not add event buffer\n"); 633 } 634 635 virtqueue_kick(vq); 636} 637 638/* IOMMU API */ 639 640static struct iommu_domain *viommu_domain_alloc(unsigned type) 641{ 642 struct viommu_domain *vdomain; 643 644 if (type != IOMMU_DOMAIN_UNMANAGED && 645 type != IOMMU_DOMAIN_DMA && 646 type != IOMMU_DOMAIN_IDENTITY) 647 return NULL; 648 649 vdomain = kzalloc(sizeof(*vdomain), GFP_KERNEL); 650 if (!vdomain) 651 return NULL; 652 653 mutex_init(&vdomain->mutex); 654 spin_lock_init(&vdomain->mappings_lock); 655 vdomain->mappings = RB_ROOT_CACHED; 656 657 return &vdomain->domain; 658} 659 660static int viommu_domain_finalise(struct viommu_endpoint *vdev, 661 struct iommu_domain *domain) 662{ 663 int ret; 664 unsigned long viommu_page_size; 665 struct viommu_dev *viommu = vdev->viommu; 666 struct viommu_domain *vdomain = to_viommu_domain(domain); 667 668 viommu_page_size = 1UL << __ffs(viommu->pgsize_bitmap); 669 if (viommu_page_size > PAGE_SIZE) { 670 dev_err(vdev->dev, 671 "granule 0x%lx larger than system page size 0x%lx\n", 672 viommu_page_size, PAGE_SIZE); 673 return -ENODEV; 674 } 675 676 ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, 677 viommu->last_domain, GFP_KERNEL); 678 if (ret < 0) 679 return ret; 680 681 vdomain->id = (unsigned int)ret; 682 683 domain->pgsize_bitmap = viommu->pgsize_bitmap; 684 domain->geometry = viommu->geometry; 685 686 vdomain->map_flags = viommu->map_flags; 687 vdomain->viommu = viommu; 688 689 if (domain->type == IOMMU_DOMAIN_IDENTITY) { 690 if (virtio_has_feature(viommu->vdev, 691 VIRTIO_IOMMU_F_BYPASS_CONFIG)) { 692 vdomain->bypass = true; 693 return 0; 694 } 695 696 ret = viommu_domain_map_identity(vdev, vdomain); 697 if (ret) { 698 ida_free(&viommu->domain_ids, vdomain->id); 699 vdomain->viommu = NULL; 700 return ret; 701 } 702 } 703 704 return 0; 705} 706 707static void viommu_domain_free(struct iommu_domain *domain) 708{ 709 struct viommu_domain *vdomain = to_viommu_domain(domain); 710 711 /* Free all remaining mappings */ 712 viommu_del_mappings(vdomain, 0, ULLONG_MAX); 713 714 if (vdomain->viommu) 715 ida_free(&vdomain->viommu->domain_ids, vdomain->id); 716 717 kfree(vdomain); 718} 719 720static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) 721{ 722 int i; 723 int ret = 0; 724 struct virtio_iommu_req_attach req; 725 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); 726 struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); 727 struct viommu_domain *vdomain = to_viommu_domain(domain); 728 729 mutex_lock(&vdomain->mutex); 730 if (!vdomain->viommu) { 731 /* 732 * Properly initialize the domain now that we know which viommu 733 * owns it. 734 */ 735 ret = viommu_domain_finalise(vdev, domain); 736 } else if (vdomain->viommu != vdev->viommu) { 737 ret = -EINVAL; 738 } 739 mutex_unlock(&vdomain->mutex); 740 741 if (ret) 742 return ret; 743 744 /* 745 * In the virtio-iommu device, when attaching the endpoint to a new 746 * domain, it is detached from the old one and, if as a result the 747 * old domain isn't attached to any endpoint, all mappings are removed 748 * from the old domain and it is freed. 749 * 750 * In the driver the old domain still exists, and its mappings will be 751 * recreated if it gets reattached to an endpoint. Otherwise it will be 752 * freed explicitly. 753 * 754 * vdev->vdomain is protected by group->mutex 755 */ 756 if (vdev->vdomain) 757 vdev->vdomain->nr_endpoints--; 758 759 req = (struct virtio_iommu_req_attach) { 760 .head.type = VIRTIO_IOMMU_T_ATTACH, 761 .domain = cpu_to_le32(vdomain->id), 762 }; 763 764 if (vdomain->bypass) 765 req.flags |= cpu_to_le32(VIRTIO_IOMMU_ATTACH_F_BYPASS); 766 767 for (i = 0; i < fwspec->num_ids; i++) { 768 req.endpoint = cpu_to_le32(fwspec->ids[i]); 769 770 ret = viommu_send_req_sync(vdomain->viommu, &req, sizeof(req)); 771 if (ret) 772 return ret; 773 } 774 775 if (!vdomain->nr_endpoints) { 776 /* 777 * This endpoint is the first to be attached to the domain. 778 * Replay existing mappings (e.g. SW MSI). 779 */ 780 ret = viommu_replay_mappings(vdomain); 781 if (ret) 782 return ret; 783 } 784 785 vdomain->nr_endpoints++; 786 vdev->vdomain = vdomain; 787 788 return 0; 789} 790 791static void viommu_detach_dev(struct viommu_endpoint *vdev) 792{ 793 int i; 794 struct virtio_iommu_req_detach req; 795 struct viommu_domain *vdomain = vdev->vdomain; 796 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(vdev->dev); 797 798 if (!vdomain) 799 return; 800 801 req = (struct virtio_iommu_req_detach) { 802 .head.type = VIRTIO_IOMMU_T_DETACH, 803 .domain = cpu_to_le32(vdomain->id), 804 }; 805 806 for (i = 0; i < fwspec->num_ids; i++) { 807 req.endpoint = cpu_to_le32(fwspec->ids[i]); 808 WARN_ON(viommu_send_req_sync(vdev->viommu, &req, sizeof(req))); 809 } 810 vdomain->nr_endpoints--; 811 vdev->vdomain = NULL; 812} 813 814static int viommu_map_pages(struct iommu_domain *domain, unsigned long iova, 815 phys_addr_t paddr, size_t pgsize, size_t pgcount, 816 int prot, gfp_t gfp, size_t *mapped) 817{ 818 int ret; 819 u32 flags; 820 size_t size = pgsize * pgcount; 821 u64 end = iova + size - 1; 822 struct virtio_iommu_req_map map; 823 struct viommu_domain *vdomain = to_viommu_domain(domain); 824 825 flags = (prot & IOMMU_READ ? VIRTIO_IOMMU_MAP_F_READ : 0) | 826 (prot & IOMMU_WRITE ? VIRTIO_IOMMU_MAP_F_WRITE : 0) | 827 (prot & IOMMU_MMIO ? VIRTIO_IOMMU_MAP_F_MMIO : 0); 828 829 if (flags & ~vdomain->map_flags) 830 return -EINVAL; 831 832 ret = viommu_add_mapping(vdomain, iova, end, paddr, flags); 833 if (ret) 834 return ret; 835 836 if (vdomain->nr_endpoints) { 837 map = (struct virtio_iommu_req_map) { 838 .head.type = VIRTIO_IOMMU_T_MAP, 839 .domain = cpu_to_le32(vdomain->id), 840 .virt_start = cpu_to_le64(iova), 841 .phys_start = cpu_to_le64(paddr), 842 .virt_end = cpu_to_le64(end), 843 .flags = cpu_to_le32(flags), 844 }; 845 846 ret = viommu_add_req(vdomain->viommu, &map, sizeof(map)); 847 if (ret) { 848 viommu_del_mappings(vdomain, iova, end); 849 return ret; 850 } 851 } 852 if (mapped) 853 *mapped = size; 854 855 return 0; 856} 857 858static size_t viommu_unmap_pages(struct iommu_domain *domain, unsigned long iova, 859 size_t pgsize, size_t pgcount, 860 struct iommu_iotlb_gather *gather) 861{ 862 int ret = 0; 863 size_t unmapped; 864 struct virtio_iommu_req_unmap unmap; 865 struct viommu_domain *vdomain = to_viommu_domain(domain); 866 size_t size = pgsize * pgcount; 867 868 unmapped = viommu_del_mappings(vdomain, iova, iova + size - 1); 869 if (unmapped < size) 870 return 0; 871 872 /* Device already removed all mappings after detach. */ 873 if (!vdomain->nr_endpoints) 874 return unmapped; 875 876 unmap = (struct virtio_iommu_req_unmap) { 877 .head.type = VIRTIO_IOMMU_T_UNMAP, 878 .domain = cpu_to_le32(vdomain->id), 879 .virt_start = cpu_to_le64(iova), 880 .virt_end = cpu_to_le64(iova + unmapped - 1), 881 }; 882 883 ret = viommu_add_req(vdomain->viommu, &unmap, sizeof(unmap)); 884 return ret ? 0 : unmapped; 885} 886 887static phys_addr_t viommu_iova_to_phys(struct iommu_domain *domain, 888 dma_addr_t iova) 889{ 890 u64 paddr = 0; 891 unsigned long flags; 892 struct viommu_mapping *mapping; 893 struct interval_tree_node *node; 894 struct viommu_domain *vdomain = to_viommu_domain(domain); 895 896 spin_lock_irqsave(&vdomain->mappings_lock, flags); 897 node = interval_tree_iter_first(&vdomain->mappings, iova, iova); 898 if (node) { 899 mapping = container_of(node, struct viommu_mapping, iova); 900 paddr = mapping->paddr + (iova - mapping->iova.start); 901 } 902 spin_unlock_irqrestore(&vdomain->mappings_lock, flags); 903 904 return paddr; 905} 906 907static void viommu_iotlb_sync(struct iommu_domain *domain, 908 struct iommu_iotlb_gather *gather) 909{ 910 struct viommu_domain *vdomain = to_viommu_domain(domain); 911 912 viommu_sync_req(vdomain->viommu); 913} 914 915static int viommu_iotlb_sync_map(struct iommu_domain *domain, 916 unsigned long iova, size_t size) 917{ 918 struct viommu_domain *vdomain = to_viommu_domain(domain); 919 920 /* 921 * May be called before the viommu is initialized including 922 * while creating direct mapping 923 */ 924 if (!vdomain->nr_endpoints) 925 return 0; 926 return viommu_sync_req(vdomain->viommu); 927} 928 929static void viommu_flush_iotlb_all(struct iommu_domain *domain) 930{ 931 struct viommu_domain *vdomain = to_viommu_domain(domain); 932 933 /* 934 * May be called before the viommu is initialized including 935 * while creating direct mapping 936 */ 937 if (!vdomain->nr_endpoints) 938 return; 939 viommu_sync_req(vdomain->viommu); 940} 941 942static void viommu_get_resv_regions(struct device *dev, struct list_head *head) 943{ 944 struct iommu_resv_region *entry, *new_entry, *msi = NULL; 945 struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); 946 int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; 947 948 list_for_each_entry(entry, &vdev->resv_regions, list) { 949 if (entry->type == IOMMU_RESV_MSI) 950 msi = entry; 951 952 new_entry = kmemdup(entry, sizeof(*entry), GFP_KERNEL); 953 if (!new_entry) 954 return; 955 list_add_tail(&new_entry->list, head); 956 } 957 958 /* 959 * If the device didn't register any bypass MSI window, add a 960 * software-mapped region. 961 */ 962 if (!msi) { 963 msi = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH, 964 prot, IOMMU_RESV_SW_MSI, 965 GFP_KERNEL); 966 if (!msi) 967 return; 968 969 list_add_tail(&msi->list, head); 970 } 971 972 iommu_dma_get_resv_regions(dev, head); 973} 974 975static struct iommu_ops viommu_ops; 976static struct virtio_driver virtio_iommu_drv; 977 978static int viommu_match_node(struct device *dev, const void *data) 979{ 980 return device_match_fwnode(dev->parent, data); 981} 982 983static struct viommu_dev *viommu_get_by_fwnode(struct fwnode_handle *fwnode) 984{ 985 struct device *dev = driver_find_device(&virtio_iommu_drv.driver, NULL, 986 fwnode, viommu_match_node); 987 put_device(dev); 988 989 return dev ? dev_to_virtio(dev)->priv : NULL; 990} 991 992static struct iommu_device *viommu_probe_device(struct device *dev) 993{ 994 int ret; 995 struct viommu_endpoint *vdev; 996 struct viommu_dev *viommu = NULL; 997 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); 998 999 viommu = viommu_get_by_fwnode(fwspec->iommu_fwnode); 1000 if (!viommu) 1001 return ERR_PTR(-ENODEV); 1002 1003 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); 1004 if (!vdev) 1005 return ERR_PTR(-ENOMEM); 1006 1007 vdev->dev = dev; 1008 vdev->viommu = viommu; 1009 INIT_LIST_HEAD(&vdev->resv_regions); 1010 dev_iommu_priv_set(dev, vdev); 1011 1012 if (viommu->probe_size) { 1013 /* Get additional information for this endpoint */ 1014 ret = viommu_probe_endpoint(viommu, dev); 1015 if (ret) 1016 goto err_free_dev; 1017 } 1018 1019 return &viommu->iommu; 1020 1021err_free_dev: 1022 iommu_put_resv_regions(dev, &vdev->resv_regions); 1023 kfree(vdev); 1024 1025 return ERR_PTR(ret); 1026} 1027 1028static void viommu_probe_finalize(struct device *dev) 1029{ 1030#ifndef CONFIG_ARCH_HAS_SETUP_DMA_OPS 1031 /* First clear the DMA ops in case we're switching from a DMA domain */ 1032 set_dma_ops(dev, NULL); 1033 iommu_setup_dma_ops(dev, 0, U64_MAX); 1034#endif 1035} 1036 1037static void viommu_release_device(struct device *dev) 1038{ 1039 struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); 1040 1041 viommu_detach_dev(vdev); 1042 iommu_put_resv_regions(dev, &vdev->resv_regions); 1043 kfree(vdev); 1044} 1045 1046static struct iommu_group *viommu_device_group(struct device *dev) 1047{ 1048 if (dev_is_pci(dev)) 1049 return pci_device_group(dev); 1050 else 1051 return generic_device_group(dev); 1052} 1053 1054static int viommu_of_xlate(struct device *dev, 1055 const struct of_phandle_args *args) 1056{ 1057 return iommu_fwspec_add_ids(dev, args->args, 1); 1058} 1059 1060static bool viommu_capable(struct device *dev, enum iommu_cap cap) 1061{ 1062 switch (cap) { 1063 case IOMMU_CAP_CACHE_COHERENCY: 1064 return true; 1065 case IOMMU_CAP_DEFERRED_FLUSH: 1066 return true; 1067 default: 1068 return false; 1069 } 1070} 1071 1072static struct iommu_ops viommu_ops = { 1073 .capable = viommu_capable, 1074 .domain_alloc = viommu_domain_alloc, 1075 .probe_device = viommu_probe_device, 1076 .probe_finalize = viommu_probe_finalize, 1077 .release_device = viommu_release_device, 1078 .device_group = viommu_device_group, 1079 .get_resv_regions = viommu_get_resv_regions, 1080 .of_xlate = viommu_of_xlate, 1081 .owner = THIS_MODULE, 1082 .default_domain_ops = &(const struct iommu_domain_ops) { 1083 .attach_dev = viommu_attach_dev, 1084 .map_pages = viommu_map_pages, 1085 .unmap_pages = viommu_unmap_pages, 1086 .iova_to_phys = viommu_iova_to_phys, 1087 .flush_iotlb_all = viommu_flush_iotlb_all, 1088 .iotlb_sync = viommu_iotlb_sync, 1089 .iotlb_sync_map = viommu_iotlb_sync_map, 1090 .free = viommu_domain_free, 1091 } 1092}; 1093 1094static int viommu_init_vqs(struct viommu_dev *viommu) 1095{ 1096 struct virtio_device *vdev = dev_to_virtio(viommu->dev); 1097 const char *names[] = { "request", "event" }; 1098 vq_callback_t *callbacks[] = { 1099 NULL, /* No async requests */ 1100 viommu_event_handler, 1101 }; 1102 1103 return virtio_find_vqs(vdev, VIOMMU_NR_VQS, viommu->vqs, callbacks, 1104 names, NULL); 1105} 1106 1107static int viommu_fill_evtq(struct viommu_dev *viommu) 1108{ 1109 int i, ret; 1110 struct scatterlist sg[1]; 1111 struct viommu_event *evts; 1112 struct virtqueue *vq = viommu->vqs[VIOMMU_EVENT_VQ]; 1113 size_t nr_evts = vq->num_free; 1114 1115 viommu->evts = evts = devm_kmalloc_array(viommu->dev, nr_evts, 1116 sizeof(*evts), GFP_KERNEL); 1117 if (!evts) 1118 return -ENOMEM; 1119 1120 for (i = 0; i < nr_evts; i++) { 1121 sg_init_one(sg, &evts[i], sizeof(*evts)); 1122 ret = virtqueue_add_inbuf(vq, sg, 1, &evts[i], GFP_KERNEL); 1123 if (ret) 1124 return ret; 1125 } 1126 1127 return 0; 1128} 1129 1130static int viommu_probe(struct virtio_device *vdev) 1131{ 1132 struct device *parent_dev = vdev->dev.parent; 1133 struct viommu_dev *viommu = NULL; 1134 struct device *dev = &vdev->dev; 1135 u64 input_start = 0; 1136 u64 input_end = -1UL; 1137 int ret; 1138 1139 if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1) || 1140 !virtio_has_feature(vdev, VIRTIO_IOMMU_F_MAP_UNMAP)) 1141 return -ENODEV; 1142 1143 viommu = devm_kzalloc(dev, sizeof(*viommu), GFP_KERNEL); 1144 if (!viommu) 1145 return -ENOMEM; 1146 1147 spin_lock_init(&viommu->request_lock); 1148 ida_init(&viommu->domain_ids); 1149 viommu->dev = dev; 1150 viommu->vdev = vdev; 1151 INIT_LIST_HEAD(&viommu->requests); 1152 1153 ret = viommu_init_vqs(viommu); 1154 if (ret) 1155 return ret; 1156 1157 virtio_cread_le(vdev, struct virtio_iommu_config, page_size_mask, 1158 &viommu->pgsize_bitmap); 1159 1160 if (!viommu->pgsize_bitmap) { 1161 ret = -EINVAL; 1162 goto err_free_vqs; 1163 } 1164 1165 viommu->map_flags = VIRTIO_IOMMU_MAP_F_READ | VIRTIO_IOMMU_MAP_F_WRITE; 1166 viommu->last_domain = ~0U; 1167 1168 /* Optional features */ 1169 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, 1170 struct virtio_iommu_config, input_range.start, 1171 &input_start); 1172 1173 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, 1174 struct virtio_iommu_config, input_range.end, 1175 &input_end); 1176 1177 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE, 1178 struct virtio_iommu_config, domain_range.start, 1179 &viommu->first_domain); 1180 1181 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE, 1182 struct virtio_iommu_config, domain_range.end, 1183 &viommu->last_domain); 1184 1185 virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_PROBE, 1186 struct virtio_iommu_config, probe_size, 1187 &viommu->probe_size); 1188 1189 viommu->geometry = (struct iommu_domain_geometry) { 1190 .aperture_start = input_start, 1191 .aperture_end = input_end, 1192 .force_aperture = true, 1193 }; 1194 1195 if (virtio_has_feature(vdev, VIRTIO_IOMMU_F_MMIO)) 1196 viommu->map_flags |= VIRTIO_IOMMU_MAP_F_MMIO; 1197 1198 viommu_ops.pgsize_bitmap = viommu->pgsize_bitmap; 1199 1200 virtio_device_ready(vdev); 1201 1202 /* Populate the event queue with buffers */ 1203 ret = viommu_fill_evtq(viommu); 1204 if (ret) 1205 goto err_free_vqs; 1206 1207 ret = iommu_device_sysfs_add(&viommu->iommu, dev, NULL, "%s", 1208 virtio_bus_name(vdev)); 1209 if (ret) 1210 goto err_free_vqs; 1211 1212 iommu_device_register(&viommu->iommu, &viommu_ops, parent_dev); 1213 1214 vdev->priv = viommu; 1215 1216 dev_info(dev, "input address: %u bits\n", 1217 order_base_2(viommu->geometry.aperture_end)); 1218 dev_info(dev, "page mask: %#llx\n", viommu->pgsize_bitmap); 1219 1220 return 0; 1221 1222err_free_vqs: 1223 vdev->config->del_vqs(vdev); 1224 1225 return ret; 1226} 1227 1228static void viommu_remove(struct virtio_device *vdev) 1229{ 1230 struct viommu_dev *viommu = vdev->priv; 1231 1232 iommu_device_sysfs_remove(&viommu->iommu); 1233 iommu_device_unregister(&viommu->iommu); 1234 1235 /* Stop all virtqueues */ 1236 virtio_reset_device(vdev); 1237 vdev->config->del_vqs(vdev); 1238 1239 dev_info(&vdev->dev, "device removed\n"); 1240} 1241 1242static void viommu_config_changed(struct virtio_device *vdev) 1243{ 1244 dev_warn(&vdev->dev, "config changed\n"); 1245} 1246 1247static unsigned int features[] = { 1248 VIRTIO_IOMMU_F_MAP_UNMAP, 1249 VIRTIO_IOMMU_F_INPUT_RANGE, 1250 VIRTIO_IOMMU_F_DOMAIN_RANGE, 1251 VIRTIO_IOMMU_F_PROBE, 1252 VIRTIO_IOMMU_F_MMIO, 1253 VIRTIO_IOMMU_F_BYPASS_CONFIG, 1254}; 1255 1256static struct virtio_device_id id_table[] = { 1257 { VIRTIO_ID_IOMMU, VIRTIO_DEV_ANY_ID }, 1258 { 0 }, 1259}; 1260MODULE_DEVICE_TABLE(virtio, id_table); 1261 1262static struct virtio_driver virtio_iommu_drv = { 1263 .driver.name = KBUILD_MODNAME, 1264 .driver.owner = THIS_MODULE, 1265 .id_table = id_table, 1266 .feature_table = features, 1267 .feature_table_size = ARRAY_SIZE(features), 1268 .probe = viommu_probe, 1269 .remove = viommu_remove, 1270 .config_changed = viommu_config_changed, 1271}; 1272 1273module_virtio_driver(virtio_iommu_drv); 1274 1275MODULE_DESCRIPTION("Virtio IOMMU driver"); 1276MODULE_AUTHOR("Jean-Philippe Brucker <jean-philippe.brucker@arm.com>"); 1277MODULE_LICENSE("GPL v2"); 1278