drivers/iommu/virtio-iommu.c

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

DEFINITIONS
