| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Virtio driver for the paravirtualized IOMMU |
| * |
| * Copyright (C) 2019 Arm Limited |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/amba/bus.h> |
| #include <linux/delay.h> |
| #include <linux/dma-iommu.h> |
| #include <linux/dma-map-ops.h> |
| #include <linux/freezer.h> |
| #include <linux/interval_tree.h> |
| #include <linux/iommu.h> |
| #include <linux/module.h> |
| #include <linux/of_platform.h> |
| #include <linux/pci.h> |
| #include <linux/platform_device.h> |
| #include <linux/virtio.h> |
| #include <linux/virtio_config.h> |
| #include <linux/virtio_ids.h> |
| #include <linux/wait.h> |
| |
| #include <uapi/linux/virtio_iommu.h> |
| |
| #define MSI_IOVA_BASE 0x8000000 |
| #define MSI_IOVA_LENGTH 0x100000 |
| |
| #define VIOMMU_REQUEST_VQ 0 |
| #define VIOMMU_EVENT_VQ 1 |
| #define VIOMMU_NR_VQS 2 |
| |
| struct viommu_dev { |
| struct iommu_device iommu; |
| struct device *dev; |
| struct virtio_device *vdev; |
| |
| struct ida domain_ids; |
| |
| struct virtqueue *vqs[VIOMMU_NR_VQS]; |
| spinlock_t request_lock; |
| struct list_head requests; |
| void *evts; |
| |
| /* Device configuration */ |
| struct iommu_domain_geometry geometry; |
| u64 pgsize_bitmap; |
| u32 first_domain; |
| u32 last_domain; |
| /* Supported MAP flags */ |
| u32 map_flags; |
| u32 probe_size; |
| }; |
| |
| struct viommu_mapping { |
| phys_addr_t paddr; |
| struct interval_tree_node iova; |
| u32 flags; |
| }; |
| |
| struct viommu_domain { |
| struct iommu_domain domain; |
| struct viommu_dev *viommu; |
| struct mutex mutex; /* protects viommu pointer */ |
| unsigned int id; |
| u32 map_flags; |
| |
| spinlock_t mappings_lock; |
| struct rb_root_cached mappings; |
| |
| unsigned long nr_endpoints; |
| bool bypass; |
| }; |
| |
| struct viommu_endpoint { |
| struct device *dev; |
| struct viommu_dev *viommu; |
| struct viommu_domain *vdomain; |
| struct list_head resv_regions; |
| }; |
| |
| struct viommu_request { |
| struct list_head list; |
| void *writeback; |
| unsigned int write_offset; |
| unsigned int len; |
| char buf[]; |
| }; |
| |
| #define VIOMMU_FAULT_RESV_MASK 0xffffff00 |
| |
| struct viommu_event { |
| union { |
| u32 head; |
| struct virtio_iommu_fault fault; |
| }; |
| }; |
| |
| #define to_viommu_domain(domain) \ |
| container_of(domain, struct viommu_domain, domain) |
| |
| static int viommu_get_req_errno(void *buf, size_t len) |
| { |
| struct virtio_iommu_req_tail *tail = buf + len - sizeof(*tail); |
| |
| switch (tail->status) { |
| case VIRTIO_IOMMU_S_OK: |
| return 0; |
| case VIRTIO_IOMMU_S_UNSUPP: |
| return -ENOSYS; |
| case VIRTIO_IOMMU_S_INVAL: |
| return -EINVAL; |
| case VIRTIO_IOMMU_S_RANGE: |
| return -ERANGE; |
| case VIRTIO_IOMMU_S_NOENT: |
| return -ENOENT; |
| case VIRTIO_IOMMU_S_FAULT: |
| return -EFAULT; |
| case VIRTIO_IOMMU_S_NOMEM: |
| return -ENOMEM; |
| case VIRTIO_IOMMU_S_IOERR: |
| case VIRTIO_IOMMU_S_DEVERR: |
| default: |
| return -EIO; |
| } |
| } |
| |
| static void viommu_set_req_status(void *buf, size_t len, int status) |
| { |
| struct virtio_iommu_req_tail *tail = buf + len - sizeof(*tail); |
| |
| tail->status = status; |
| } |
| |
| static off_t viommu_get_write_desc_offset(struct viommu_dev *viommu, |
| struct virtio_iommu_req_head *req, |
| size_t len) |
| { |
| size_t tail_size = sizeof(struct virtio_iommu_req_tail); |
| |
| if (req->type == VIRTIO_IOMMU_T_PROBE) |
| return len - viommu->probe_size - tail_size; |
| |
| return len - tail_size; |
| } |
| |
| /* |
| * __viommu_sync_req - Complete all in-flight requests |
| * |
| * Wait for all added requests to complete. When this function returns, all |
| * requests that were in-flight at the time of the call have completed. |
| */ |
| static int __viommu_sync_req(struct viommu_dev *viommu) |
| { |
| unsigned int len; |
| size_t write_len; |
| struct viommu_request *req; |
| struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; |
| |
| assert_spin_locked(&viommu->request_lock); |
| |
| virtqueue_kick(vq); |
| |
| while (!list_empty(&viommu->requests)) { |
| len = 0; |
| req = virtqueue_get_buf(vq, &len); |
| if (!req) |
| continue; |
| |
| if (!len) |
| viommu_set_req_status(req->buf, req->len, |
| VIRTIO_IOMMU_S_IOERR); |
| |
| write_len = req->len - req->write_offset; |
| if (req->writeback && len == write_len) |
| memcpy(req->writeback, req->buf + req->write_offset, |
| write_len); |
| |
| list_del(&req->list); |
| kfree(req); |
| } |
| |
| return 0; |
| } |
| |
| static int viommu_sync_req(struct viommu_dev *viommu) |
| { |
| int ret; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&viommu->request_lock, flags); |
| ret = __viommu_sync_req(viommu); |
| if (ret) |
| dev_dbg(viommu->dev, "could not sync requests (%d)\n", ret); |
| spin_unlock_irqrestore(&viommu->request_lock, flags); |
| |
| return ret; |
| } |
| |
| /* |
| * __viommu_add_request - Add one request to the queue |
| * @buf: pointer to the request buffer |
| * @len: length of the request buffer |
| * @writeback: copy data back to the buffer when the request completes. |
| * |
| * Add a request to the queue. Only synchronize the queue if it's already full. |
| * Otherwise don't kick the queue nor wait for requests to complete. |
| * |
| * When @writeback is true, data written by the device, including the request |
| * status, is copied into @buf after the request completes. This is unsafe if |
| * the caller allocates @buf on stack and drops the lock between add_req() and |
| * sync_req(). |
| * |
| * Return 0 if the request was successfully added to the queue. |
| */ |
| static int __viommu_add_req(struct viommu_dev *viommu, void *buf, size_t len, |
| bool writeback) |
| { |
| int ret; |
| off_t write_offset; |
| struct viommu_request *req; |
| struct scatterlist top_sg, bottom_sg; |
| struct scatterlist *sg[2] = { &top_sg, &bottom_sg }; |
| struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; |
| |
| assert_spin_locked(&viommu->request_lock); |
| |
| write_offset = viommu_get_write_desc_offset(viommu, buf, len); |
| if (write_offset <= 0) |
| return -EINVAL; |
| |
| req = kzalloc(sizeof(*req) + len, GFP_ATOMIC); |
| if (!req) |
| return -ENOMEM; |
| |
| req->len = len; |
| if (writeback) { |
| req->writeback = buf + write_offset; |
| req->write_offset = write_offset; |
| } |
| memcpy(&req->buf, buf, write_offset); |
| |
| sg_init_one(&top_sg, req->buf, write_offset); |
| sg_init_one(&bottom_sg, req->buf + write_offset, len - write_offset); |
| |
| ret = virtqueue_add_sgs(vq, sg, 1, 1, req, GFP_ATOMIC); |
| if (ret == -ENOSPC) { |
| /* If the queue is full, sync and retry */ |
| if (!__viommu_sync_req(viommu)) |
| ret = virtqueue_add_sgs(vq, sg, 1, 1, req, GFP_ATOMIC); |
| } |
| if (ret) |
| goto err_free; |
| |
| list_add_tail(&req->list, &viommu->requests); |
| return 0; |
| |
| err_free: |
| kfree(req); |
| return ret; |
| } |
| |
| static int viommu_add_req(struct viommu_dev *viommu, void *buf, size_t len) |
| { |
| int ret; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&viommu->request_lock, flags); |
| ret = __viommu_add_req(viommu, buf, len, false); |
| if (ret) |
| dev_dbg(viommu->dev, "could not add request: %d\n", ret); |
| spin_unlock_irqrestore(&viommu->request_lock, flags); |
| |
| return ret; |
| } |
| |
| /* |
| * Send a request and wait for it to complete. Return the request status (as an |
| * errno) |
| */ |
| static int viommu_send_req_sync(struct viommu_dev *viommu, void *buf, |
| size_t len) |
| { |
| int ret; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&viommu->request_lock, flags); |
| |
| ret = __viommu_add_req(viommu, buf, len, true); |
| if (ret) { |
| dev_dbg(viommu->dev, "could not add request (%d)\n", ret); |
| goto out_unlock; |
| } |
| |
| ret = __viommu_sync_req(viommu); |
| if (ret) { |
| dev_dbg(viommu->dev, "could not sync requests (%d)\n", ret); |
| /* Fall-through (get the actual request status) */ |
| } |
| |
| ret = viommu_get_req_errno(buf, len); |
| out_unlock: |
| spin_unlock_irqrestore(&viommu->request_lock, flags); |
| return ret; |
| } |
| |
| /* |
| * viommu_add_mapping - add a mapping to the internal tree |
| * |
| * On success, return the new mapping. Otherwise return NULL. |
| */ |
| static int viommu_add_mapping(struct viommu_domain *vdomain, u64 iova, u64 end, |
| phys_addr_t paddr, u32 flags) |
| { |
| unsigned long irqflags; |
| struct viommu_mapping *mapping; |
| |
| mapping = kzalloc(sizeof(*mapping), GFP_ATOMIC); |
| if (!mapping) |
| return -ENOMEM; |
| |
| mapping->paddr = paddr; |
| mapping->iova.start = iova; |
| mapping->iova.last = end; |
| mapping->flags = flags; |
| |
| spin_lock_irqsave(&vdomain->mappings_lock, irqflags); |
| interval_tree_insert(&mapping->iova, &vdomain->mappings); |
| spin_unlock_irqrestore(&vdomain->mappings_lock, irqflags); |
| |
| return 0; |
| } |
| |
| /* |
| * viommu_del_mappings - remove mappings from the internal tree |
| * |
| * @vdomain: the domain |
| * @iova: start of the range |
| * @end: end of the range |
| * |
| * On success, returns the number of unmapped bytes |
| */ |
| static size_t viommu_del_mappings(struct viommu_domain *vdomain, |
| u64 iova, u64 end) |
| { |
| size_t unmapped = 0; |
| unsigned long flags; |
| struct viommu_mapping *mapping = NULL; |
| struct interval_tree_node *node, *next; |
| |
| spin_lock_irqsave(&vdomain->mappings_lock, flags); |
| next = interval_tree_iter_first(&vdomain->mappings, iova, end); |
| while (next) { |
| node = next; |
| mapping = container_of(node, struct viommu_mapping, iova); |
| next = interval_tree_iter_next(node, iova, end); |
| |
| /* Trying to split a mapping? */ |
| if (mapping->iova.start < iova) |
| break; |
| |
| /* |
| * Virtio-iommu doesn't allow UNMAP to split a mapping created |
| * with a single MAP request, so remove the full mapping. |
| */ |
| unmapped += mapping->iova.last - mapping->iova.start + 1; |
| |
| interval_tree_remove(node, &vdomain->mappings); |
| kfree(mapping); |
| } |
| spin_unlock_irqrestore(&vdomain->mappings_lock, flags); |
| |
| return unmapped; |
| } |
| |
| /* |
| * Fill the domain with identity mappings, skipping the device's reserved |
| * regions. |
| */ |
| static int viommu_domain_map_identity(struct viommu_endpoint *vdev, |
| struct viommu_domain *vdomain) |
| { |
| int ret; |
| struct iommu_resv_region *resv; |
| u64 iova = vdomain->domain.geometry.aperture_start; |
| u64 limit = vdomain->domain.geometry.aperture_end; |
| u32 flags = VIRTIO_IOMMU_MAP_F_READ | VIRTIO_IOMMU_MAP_F_WRITE; |
| unsigned long granule = 1UL << __ffs(vdomain->domain.pgsize_bitmap); |
| |
| iova = ALIGN(iova, granule); |
| limit = ALIGN_DOWN(limit + 1, granule) - 1; |
| |
| list_for_each_entry(resv, &vdev->resv_regions, list) { |
| u64 resv_start = ALIGN_DOWN(resv->start, granule); |
| u64 resv_end = ALIGN(resv->start + resv->length, granule) - 1; |
| |
| if (resv_end < iova || resv_start > limit) |
| /* No overlap */ |
| continue; |
| |
| if (resv_start > iova) { |
| ret = viommu_add_mapping(vdomain, iova, resv_start - 1, |
| (phys_addr_t)iova, flags); |
| if (ret) |
| goto err_unmap; |
| } |
| |
| if (resv_end >= limit) |
| return 0; |
| |
| iova = resv_end + 1; |
| } |
| |
| ret = viommu_add_mapping(vdomain, iova, limit, (phys_addr_t)iova, |
| flags); |
| if (ret) |
| goto err_unmap; |
| return 0; |
| |
| err_unmap: |
| viommu_del_mappings(vdomain, 0, iova); |
| return ret; |
| } |
| |
| /* |
| * viommu_replay_mappings - re-send MAP requests |
| * |
| * When reattaching a domain that was previously detached from all endpoints, |
| * mappings were deleted from the device. Re-create the mappings available in |
| * the internal tree. |
| */ |
| static int viommu_replay_mappings(struct viommu_domain *vdomain) |
| { |
| int ret = 0; |
| unsigned long flags; |
| struct viommu_mapping *mapping; |
| struct interval_tree_node *node; |
| struct virtio_iommu_req_map map; |
| |
| spin_lock_irqsave(&vdomain->mappings_lock, flags); |
| node = interval_tree_iter_first(&vdomain->mappings, 0, -1UL); |
| while (node) { |
| mapping = container_of(node, struct viommu_mapping, iova); |
| map = (struct virtio_iommu_req_map) { |
| .head.type = VIRTIO_IOMMU_T_MAP, |
| .domain = cpu_to_le32(vdomain->id), |
| .virt_start = cpu_to_le64(mapping->iova.start), |
| .virt_end = cpu_to_le64(mapping->iova.last), |
| .phys_start = cpu_to_le64(mapping->paddr), |
| .flags = cpu_to_le32(mapping->flags), |
| }; |
| |
| ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map)); |
| if (ret) |
| break; |
| |
| node = interval_tree_iter_next(node, 0, -1UL); |
| } |
| spin_unlock_irqrestore(&vdomain->mappings_lock, flags); |
| |
| return ret; |
| } |
| |
| static int viommu_add_resv_mem(struct viommu_endpoint *vdev, |
| struct virtio_iommu_probe_resv_mem *mem, |
| size_t len) |
| { |
| size_t size; |
| u64 start64, end64; |
| phys_addr_t start, end; |
| struct iommu_resv_region *region = NULL, *next; |
| unsigned long prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; |
| |
| start = start64 = le64_to_cpu(mem->start); |
| end = end64 = le64_to_cpu(mem->end); |
| size = end64 - start64 + 1; |
| |
| /* Catch any overflow, including the unlikely end64 - start64 + 1 = 0 */ |
| if (start != start64 || end != end64 || size < end64 - start64) |
| return -EOVERFLOW; |
| |
| if (len < sizeof(*mem)) |
| return -EINVAL; |
| |
| switch (mem->subtype) { |
| default: |
| dev_warn(vdev->dev, "unknown resv mem subtype 0x%x\n", |
| mem->subtype); |
| fallthrough; |
| case VIRTIO_IOMMU_RESV_MEM_T_RESERVED: |
| region = iommu_alloc_resv_region(start, size, 0, |
| IOMMU_RESV_RESERVED); |
| break; |
| case VIRTIO_IOMMU_RESV_MEM_T_MSI: |
| region = iommu_alloc_resv_region(start, size, prot, |
| IOMMU_RESV_MSI); |
| break; |
| } |
| if (!region) |
| return -ENOMEM; |
| |
| /* Keep the list sorted */ |
| list_for_each_entry(next, &vdev->resv_regions, list) { |
| if (next->start > region->start) |
| break; |
| } |
| list_add_tail(®ion->list, &next->list); |
| return 0; |
| } |
| |
| static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev) |
| { |
| int ret; |
| u16 type, len; |
| size_t cur = 0; |
| size_t probe_len; |
| struct virtio_iommu_req_probe *probe; |
| struct virtio_iommu_probe_property *prop; |
| struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); |
| struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); |
| |
| if (!fwspec->num_ids) |
| return -EINVAL; |
| |
| probe_len = sizeof(*probe) + viommu->probe_size + |
| sizeof(struct virtio_iommu_req_tail); |
| probe = kzalloc(probe_len, GFP_KERNEL); |
| if (!probe) |
| return -ENOMEM; |
| |
| probe->head.type = VIRTIO_IOMMU_T_PROBE; |
| /* |
| * For now, assume that properties of an endpoint that outputs multiple |
| * IDs are consistent. Only probe the first one. |
| */ |
| probe->endpoint = cpu_to_le32(fwspec->ids[0]); |
| |
| ret = viommu_send_req_sync(viommu, probe, probe_len); |
| if (ret) |
| goto out_free; |
| |
| prop = (void *)probe->properties; |
| type = le16_to_cpu(prop->type) & VIRTIO_IOMMU_PROBE_T_MASK; |
| |
| while (type != VIRTIO_IOMMU_PROBE_T_NONE && |
| cur < viommu->probe_size) { |
| len = le16_to_cpu(prop->length) + sizeof(*prop); |
| |
| switch (type) { |
| case VIRTIO_IOMMU_PROBE_T_RESV_MEM: |
| ret = viommu_add_resv_mem(vdev, (void *)prop, len); |
| break; |
| default: |
| dev_err(dev, "unknown viommu prop 0x%x\n", type); |
| } |
| |
| if (ret) |
| dev_err(dev, "failed to parse viommu prop 0x%x\n", type); |
| |
| cur += len; |
| if (cur >= viommu->probe_size) |
| break; |
| |
| prop = (void *)probe->properties + cur; |
| type = le16_to_cpu(prop->type) & VIRTIO_IOMMU_PROBE_T_MASK; |
| } |
| |
| out_free: |
| kfree(probe); |
| return ret; |
| } |
| |
| static int viommu_fault_handler(struct viommu_dev *viommu, |
| struct virtio_iommu_fault *fault) |
| { |
| char *reason_str; |
| |
| u8 reason = fault->reason; |
| u32 flags = le32_to_cpu(fault->flags); |
| u32 endpoint = le32_to_cpu(fault->endpoint); |
| u64 address = le64_to_cpu(fault->address); |
| |
| switch (reason) { |
| case VIRTIO_IOMMU_FAULT_R_DOMAIN: |
| reason_str = "domain"; |
| break; |
| case VIRTIO_IOMMU_FAULT_R_MAPPING: |
| reason_str = "page"; |
| break; |
| case VIRTIO_IOMMU_FAULT_R_UNKNOWN: |
| default: |
| reason_str = "unknown"; |
| break; |
| } |
| |
| /* TODO: find EP by ID and report_iommu_fault */ |
| if (flags & VIRTIO_IOMMU_FAULT_F_ADDRESS) |
| dev_err_ratelimited(viommu->dev, "%s fault from EP %u at %#llx [%s%s%s]\n", |
| reason_str, endpoint, address, |
| flags & VIRTIO_IOMMU_FAULT_F_READ ? "R" : "", |
| flags & VIRTIO_IOMMU_FAULT_F_WRITE ? "W" : "", |
| flags & VIRTIO_IOMMU_FAULT_F_EXEC ? "X" : ""); |
| else |
| dev_err_ratelimited(viommu->dev, "%s fault from EP %u\n", |
| reason_str, endpoint); |
| return 0; |
| } |
| |
| static void viommu_event_handler(struct virtqueue *vq) |
| { |
| int ret; |
| unsigned int len; |
| struct scatterlist sg[1]; |
| struct viommu_event *evt; |
| struct viommu_dev *viommu = vq->vdev->priv; |
| |
| while ((evt = virtqueue_get_buf(vq, &len)) != NULL) { |
| if (len > sizeof(*evt)) { |
| dev_err(viommu->dev, |
| "invalid event buffer (len %u != %zu)\n", |
| len, sizeof(*evt)); |
| } else if (!(evt->head & VIOMMU_FAULT_RESV_MASK)) { |
| viommu_fault_handler(viommu, &evt->fault); |
| } |
| |
| sg_init_one(sg, evt, sizeof(*evt)); |
| ret = virtqueue_add_inbuf(vq, sg, 1, evt, GFP_ATOMIC); |
| if (ret) |
| dev_err(viommu->dev, "could not add event buffer\n"); |
| } |
| |
| virtqueue_kick(vq); |
| } |
| |
| /* IOMMU API */ |
| |
| static struct iommu_domain *viommu_domain_alloc(unsigned type) |
| { |
| struct viommu_domain *vdomain; |
| |
| if (type != IOMMU_DOMAIN_UNMANAGED && |
| type != IOMMU_DOMAIN_DMA && |
| type != IOMMU_DOMAIN_IDENTITY) |
| return NULL; |
| |
| vdomain = kzalloc(sizeof(*vdomain), GFP_KERNEL); |
| if (!vdomain) |
| return NULL; |
| |
| mutex_init(&vdomain->mutex); |
| spin_lock_init(&vdomain->mappings_lock); |
| vdomain->mappings = RB_ROOT_CACHED; |
| |
| return &vdomain->domain; |
| } |
| |
| static int viommu_domain_finalise(struct viommu_endpoint *vdev, |
| struct iommu_domain *domain) |
| { |
| int ret; |
| unsigned long viommu_page_size; |
| struct viommu_dev *viommu = vdev->viommu; |
| struct viommu_domain *vdomain = to_viommu_domain(domain); |
| |
| viommu_page_size = 1UL << __ffs(viommu->pgsize_bitmap); |
| if (viommu_page_size > PAGE_SIZE) { |
| dev_err(vdev->dev, |
| "granule 0x%lx larger than system page size 0x%lx\n", |
| viommu_page_size, PAGE_SIZE); |
| return -EINVAL; |
| } |
| |
| ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, |
| viommu->last_domain, GFP_KERNEL); |
| if (ret < 0) |
| return ret; |
| |
| vdomain->id = (unsigned int)ret; |
| |
| domain->pgsize_bitmap = viommu->pgsize_bitmap; |
| domain->geometry = viommu->geometry; |
| |
| vdomain->map_flags = viommu->map_flags; |
| vdomain->viommu = viommu; |
| |
| if (domain->type == IOMMU_DOMAIN_IDENTITY) { |
| if (virtio_has_feature(viommu->vdev, |
| VIRTIO_IOMMU_F_BYPASS_CONFIG)) { |
| vdomain->bypass = true; |
| return 0; |
| } |
| |
| ret = viommu_domain_map_identity(vdev, vdomain); |
| if (ret) { |
| ida_free(&viommu->domain_ids, vdomain->id); |
| vdomain->viommu = NULL; |
| return -EOPNOTSUPP; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static void viommu_domain_free(struct iommu_domain *domain) |
| { |
| struct viommu_domain *vdomain = to_viommu_domain(domain); |
| |
| /* Free all remaining mappings */ |
| viommu_del_mappings(vdomain, 0, ULLONG_MAX); |
| |
| if (vdomain->viommu) |
| ida_free(&vdomain->viommu->domain_ids, vdomain->id); |
| |
| kfree(vdomain); |
| } |
| |
| static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) |
| { |
| int i; |
| int ret = 0; |
| struct virtio_iommu_req_attach req; |
| struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); |
| struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); |
| struct viommu_domain *vdomain = to_viommu_domain(domain); |
| |
| mutex_lock(&vdomain->mutex); |
| if (!vdomain->viommu) { |
| /* |
| * Properly initialize the domain now that we know which viommu |
| * owns it. |
| */ |
| ret = viommu_domain_finalise(vdev, domain); |
| } else if (vdomain->viommu != vdev->viommu) { |
| dev_err(dev, "cannot attach to foreign vIOMMU\n"); |
| ret = -EXDEV; |
| } |
| mutex_unlock(&vdomain->mutex); |
| |
| if (ret) |
| return ret; |
| |
| /* |
| * In the virtio-iommu device, when attaching the endpoint to a new |
| * domain, it is detached from the old one and, if as a result the |
| * old domain isn't attached to any endpoint, all mappings are removed |
| * from the old domain and it is freed. |
| * |
| * In the driver the old domain still exists, and its mappings will be |
| * recreated if it gets reattached to an endpoint. Otherwise it will be |
| * freed explicitly. |
| * |
| * vdev->vdomain is protected by group->mutex |
| */ |
| if (vdev->vdomain) |
| vdev->vdomain->nr_endpoints--; |
| |
| req = (struct virtio_iommu_req_attach) { |
| .head.type = VIRTIO_IOMMU_T_ATTACH, |
| .domain = cpu_to_le32(vdomain->id), |
| }; |
| |
| if (vdomain->bypass) |
| req.flags |= cpu_to_le32(VIRTIO_IOMMU_ATTACH_F_BYPASS); |
| |
| for (i = 0; i < fwspec->num_ids; i++) { |
| req.endpoint = cpu_to_le32(fwspec->ids[i]); |
| |
| ret = viommu_send_req_sync(vdomain->viommu, &req, sizeof(req)); |
| if (ret) |
| return ret; |
| } |
| |
| if (!vdomain->nr_endpoints) { |
| /* |
| * This endpoint is the first to be attached to the domain. |
| * Replay existing mappings (e.g. SW MSI). |
| */ |
| ret = viommu_replay_mappings(vdomain); |
| if (ret) |
| return ret; |
| } |
| |
| vdomain->nr_endpoints++; |
| vdev->vdomain = vdomain; |
| |
| return 0; |
| } |
| |
| static int viommu_map(struct iommu_domain *domain, unsigned long iova, |
| phys_addr_t paddr, size_t size, int prot, gfp_t gfp) |
| { |
| int ret; |
| u32 flags; |
| u64 end = iova + size - 1; |
| struct virtio_iommu_req_map map; |
| struct viommu_domain *vdomain = to_viommu_domain(domain); |
| |
| flags = (prot & IOMMU_READ ? VIRTIO_IOMMU_MAP_F_READ : 0) | |
| (prot & IOMMU_WRITE ? VIRTIO_IOMMU_MAP_F_WRITE : 0) | |
| (prot & IOMMU_MMIO ? VIRTIO_IOMMU_MAP_F_MMIO : 0); |
| |
| if (flags & ~vdomain->map_flags) |
| return -EINVAL; |
| |
| ret = viommu_add_mapping(vdomain, iova, end, paddr, flags); |
| if (ret) |
| return ret; |
| |
| map = (struct virtio_iommu_req_map) { |
| .head.type = VIRTIO_IOMMU_T_MAP, |
| .domain = cpu_to_le32(vdomain->id), |
| .virt_start = cpu_to_le64(iova), |
| .phys_start = cpu_to_le64(paddr), |
| .virt_end = cpu_to_le64(end), |
| .flags = cpu_to_le32(flags), |
| }; |
| |
| if (!vdomain->nr_endpoints) |
| return 0; |
| |
| ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map)); |
| if (ret) |
| viommu_del_mappings(vdomain, iova, end); |
| |
| return ret; |
| } |
| |
| static size_t viommu_unmap(struct iommu_domain *domain, unsigned long iova, |
| size_t size, struct iommu_iotlb_gather *gather) |
| { |
| int ret = 0; |
| size_t unmapped; |
| struct virtio_iommu_req_unmap unmap; |
| struct viommu_domain *vdomain = to_viommu_domain(domain); |
| |
| unmapped = viommu_del_mappings(vdomain, iova, iova + size - 1); |
| if (unmapped < size) |
| return 0; |
| |
| /* Device already removed all mappings after detach. */ |
| if (!vdomain->nr_endpoints) |
| return unmapped; |
| |
| unmap = (struct virtio_iommu_req_unmap) { |
| .head.type = VIRTIO_IOMMU_T_UNMAP, |
| .domain = cpu_to_le32(vdomain->id), |
| .virt_start = cpu_to_le64(iova), |
| .virt_end = cpu_to_le64(iova + unmapped - 1), |
| }; |
| |
| ret = viommu_add_req(vdomain->viommu, &unmap, sizeof(unmap)); |
| return ret ? 0 : unmapped; |
| } |
| |
| static phys_addr_t viommu_iova_to_phys(struct iommu_domain *domain, |
| dma_addr_t iova) |
| { |
| u64 paddr = 0; |
| unsigned long flags; |
| struct viommu_mapping *mapping; |
| struct interval_tree_node *node; |
| struct viommu_domain *vdomain = to_viommu_domain(domain); |
| |
| spin_lock_irqsave(&vdomain->mappings_lock, flags); |
| node = interval_tree_iter_first(&vdomain->mappings, iova, iova); |
| if (node) { |
| mapping = container_of(node, struct viommu_mapping, iova); |
| paddr = mapping->paddr + (iova - mapping->iova.start); |
| } |
| spin_unlock_irqrestore(&vdomain->mappings_lock, flags); |
| |
| return paddr; |
| } |
| |
| static void viommu_iotlb_sync(struct iommu_domain *domain, |
| struct iommu_iotlb_gather *gather) |
| { |
| struct viommu_domain *vdomain = to_viommu_domain(domain); |
| |
| viommu_sync_req(vdomain->viommu); |
| } |
| |
| static void viommu_get_resv_regions(struct device *dev, struct list_head *head) |
| { |
| struct iommu_resv_region *entry, *new_entry, *msi = NULL; |
| struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); |
| int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; |
| |
| list_for_each_entry(entry, &vdev->resv_regions, list) { |
| if (entry->type == IOMMU_RESV_MSI) |
| msi = entry; |
| |
| new_entry = kmemdup(entry, sizeof(*entry), GFP_KERNEL); |
| if (!new_entry) |
| return; |
| list_add_tail(&new_entry->list, head); |
| } |
| |
| /* |
| * If the device didn't register any bypass MSI window, add a |
| * software-mapped region. |
| */ |
| if (!msi) { |
| msi = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH, |
| prot, IOMMU_RESV_SW_MSI); |
| if (!msi) |
| return; |
| |
| list_add_tail(&msi->list, head); |
| } |
| |
| iommu_dma_get_resv_regions(dev, head); |
| } |
| |
| static struct iommu_ops viommu_ops; |
| static struct virtio_driver virtio_iommu_drv; |
| |
| static int viommu_match_node(struct device *dev, const void *data) |
| { |
| return dev->parent->fwnode == data; |
| } |
| |
| static struct viommu_dev *viommu_get_by_fwnode(struct fwnode_handle *fwnode) |
| { |
| struct device *dev = driver_find_device(&virtio_iommu_drv.driver, NULL, |
| fwnode, viommu_match_node); |
| put_device(dev); |
| |
| return dev ? dev_to_virtio(dev)->priv : NULL; |
| } |
| |
| static struct iommu_device *viommu_probe_device(struct device *dev) |
| { |
| int ret; |
| struct viommu_endpoint *vdev; |
| struct viommu_dev *viommu = NULL; |
| struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); |
| |
| if (!fwspec || fwspec->ops != &viommu_ops) |
| return ERR_PTR(-ENODEV); |
| |
| viommu = viommu_get_by_fwnode(fwspec->iommu_fwnode); |
| if (!viommu) |
| return ERR_PTR(-ENODEV); |
| |
| vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); |
| if (!vdev) |
| return ERR_PTR(-ENOMEM); |
| |
| vdev->dev = dev; |
| vdev->viommu = viommu; |
| INIT_LIST_HEAD(&vdev->resv_regions); |
| dev_iommu_priv_set(dev, vdev); |
| |
| if (viommu->probe_size) { |
| /* Get additional information for this endpoint */ |
| ret = viommu_probe_endpoint(viommu, dev); |
| if (ret) |
| goto err_free_dev; |
| } |
| |
| return &viommu->iommu; |
| |
| err_free_dev: |
| generic_iommu_put_resv_regions(dev, &vdev->resv_regions); |
| kfree(vdev); |
| |
| return ERR_PTR(ret); |
| } |
| |
| static void viommu_probe_finalize(struct device *dev) |
| { |
| #ifndef CONFIG_ARCH_HAS_SETUP_DMA_OPS |
| /* First clear the DMA ops in case we're switching from a DMA domain */ |
| set_dma_ops(dev, NULL); |
| iommu_setup_dma_ops(dev, 0, U64_MAX); |
| #endif |
| } |
| |
| static void viommu_release_device(struct device *dev) |
| { |
| struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); |
| struct viommu_endpoint *vdev; |
| |
| if (!fwspec || fwspec->ops != &viommu_ops) |
| return; |
| |
| vdev = dev_iommu_priv_get(dev); |
| |
| generic_iommu_put_resv_regions(dev, &vdev->resv_regions); |
| kfree(vdev); |
| } |
| |
| static struct iommu_group *viommu_device_group(struct device *dev) |
| { |
| if (dev_is_pci(dev)) |
| return pci_device_group(dev); |
| else |
| return generic_device_group(dev); |
| } |
| |
| static int viommu_of_xlate(struct device *dev, struct of_phandle_args *args) |
| { |
| return iommu_fwspec_add_ids(dev, args->args, 1); |
| } |
| |
| static struct iommu_ops viommu_ops = { |
| .domain_alloc = viommu_domain_alloc, |
| .probe_device = viommu_probe_device, |
| .probe_finalize = viommu_probe_finalize, |
| .release_device = viommu_release_device, |
| .device_group = viommu_device_group, |
| .get_resv_regions = viommu_get_resv_regions, |
| .put_resv_regions = generic_iommu_put_resv_regions, |
| .of_xlate = viommu_of_xlate, |
| .owner = THIS_MODULE, |
| .default_domain_ops = &(const struct iommu_domain_ops) { |
| .attach_dev = viommu_attach_dev, |
| .map = viommu_map, |
| .unmap = viommu_unmap, |
| .iova_to_phys = viommu_iova_to_phys, |
| .iotlb_sync = viommu_iotlb_sync, |
| .free = viommu_domain_free, |
| } |
| }; |
| |
| static int viommu_init_vqs(struct viommu_dev *viommu) |
| { |
| struct virtio_device *vdev = dev_to_virtio(viommu->dev); |
| const char *names[] = { "request", "event" }; |
| vq_callback_t *callbacks[] = { |
| NULL, /* No async requests */ |
| viommu_event_handler, |
| }; |
| |
| return virtio_find_vqs(vdev, VIOMMU_NR_VQS, viommu->vqs, callbacks, |
| names, NULL); |
| } |
| |
| static int viommu_fill_evtq(struct viommu_dev *viommu) |
| { |
| int i, ret; |
| struct scatterlist sg[1]; |
| struct viommu_event *evts; |
| struct virtqueue *vq = viommu->vqs[VIOMMU_EVENT_VQ]; |
| size_t nr_evts = vq->num_free; |
| |
| viommu->evts = evts = devm_kmalloc_array(viommu->dev, nr_evts, |
| sizeof(*evts), GFP_KERNEL); |
| if (!evts) |
| return -ENOMEM; |
| |
| for (i = 0; i < nr_evts; i++) { |
| sg_init_one(sg, &evts[i], sizeof(*evts)); |
| ret = virtqueue_add_inbuf(vq, sg, 1, &evts[i], GFP_KERNEL); |
| if (ret) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int viommu_probe(struct virtio_device *vdev) |
| { |
| struct device *parent_dev = vdev->dev.parent; |
| struct viommu_dev *viommu = NULL; |
| struct device *dev = &vdev->dev; |
| u64 input_start = 0; |
| u64 input_end = -1UL; |
| int ret; |
| |
| if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1) || |
| !virtio_has_feature(vdev, VIRTIO_IOMMU_F_MAP_UNMAP)) |
| return -ENODEV; |
| |
| viommu = devm_kzalloc(dev, sizeof(*viommu), GFP_KERNEL); |
| if (!viommu) |
| return -ENOMEM; |
| |
| spin_lock_init(&viommu->request_lock); |
| ida_init(&viommu->domain_ids); |
| viommu->dev = dev; |
| viommu->vdev = vdev; |
| INIT_LIST_HEAD(&viommu->requests); |
| |
| ret = viommu_init_vqs(viommu); |
| if (ret) |
| return ret; |
| |
| virtio_cread_le(vdev, struct virtio_iommu_config, page_size_mask, |
| &viommu->pgsize_bitmap); |
| |
| if (!viommu->pgsize_bitmap) { |
| ret = -EINVAL; |
| goto err_free_vqs; |
| } |
| |
| viommu->map_flags = VIRTIO_IOMMU_MAP_F_READ | VIRTIO_IOMMU_MAP_F_WRITE; |
| viommu->last_domain = ~0U; |
| |
| /* Optional features */ |
| virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, |
| struct virtio_iommu_config, input_range.start, |
| &input_start); |
| |
| virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, |
| struct virtio_iommu_config, input_range.end, |
| &input_end); |
| |
| virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE, |
| struct virtio_iommu_config, domain_range.start, |
| &viommu->first_domain); |
| |
| virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE, |
| struct virtio_iommu_config, domain_range.end, |
| &viommu->last_domain); |
| |
| virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_PROBE, |
| struct virtio_iommu_config, probe_size, |
| &viommu->probe_size); |
| |
| viommu->geometry = (struct iommu_domain_geometry) { |
| .aperture_start = input_start, |
| .aperture_end = input_end, |
| .force_aperture = true, |
| }; |
| |
| if (virtio_has_feature(vdev, VIRTIO_IOMMU_F_MMIO)) |
| viommu->map_flags |= VIRTIO_IOMMU_MAP_F_MMIO; |
| |
| viommu_ops.pgsize_bitmap = viommu->pgsize_bitmap; |
| |
| virtio_device_ready(vdev); |
| |
| /* Populate the event queue with buffers */ |
| ret = viommu_fill_evtq(viommu); |
| if (ret) |
| goto err_free_vqs; |
| |
| ret = iommu_device_sysfs_add(&viommu->iommu, dev, NULL, "%s", |
| virtio_bus_name(vdev)); |
| if (ret) |
| goto err_free_vqs; |
| |
| iommu_device_register(&viommu->iommu, &viommu_ops, parent_dev); |
| |
| #ifdef CONFIG_PCI |
| if (pci_bus_type.iommu_ops != &viommu_ops) { |
| ret = bus_set_iommu(&pci_bus_type, &viommu_ops); |
| if (ret) |
| goto err_unregister; |
| } |
| #endif |
| #ifdef CONFIG_ARM_AMBA |
| if (amba_bustype.iommu_ops != &viommu_ops) { |
| ret = bus_set_iommu(&amba_bustype, &viommu_ops); |
| if (ret) |
| goto err_unregister; |
| } |
| #endif |
| if (platform_bus_type.iommu_ops != &viommu_ops) { |
| ret = bus_set_iommu(&platform_bus_type, &viommu_ops); |
| if (ret) |
| goto err_unregister; |
| } |
| |
| vdev->priv = viommu; |
| |
| dev_info(dev, "input address: %u bits\n", |
| order_base_2(viommu->geometry.aperture_end)); |
| dev_info(dev, "page mask: %#llx\n", viommu->pgsize_bitmap); |
| |
| return 0; |
| |
| err_unregister: |
| iommu_device_sysfs_remove(&viommu->iommu); |
| iommu_device_unregister(&viommu->iommu); |
| err_free_vqs: |
| vdev->config->del_vqs(vdev); |
| |
| return ret; |
| } |
| |
| static void viommu_remove(struct virtio_device *vdev) |
| { |
| struct viommu_dev *viommu = vdev->priv; |
| |
| iommu_device_sysfs_remove(&viommu->iommu); |
| iommu_device_unregister(&viommu->iommu); |
| |
| /* Stop all virtqueues */ |
| virtio_reset_device(vdev); |
| vdev->config->del_vqs(vdev); |
| |
| dev_info(&vdev->dev, "device removed\n"); |
| } |
| |
| static void viommu_config_changed(struct virtio_device *vdev) |
| { |
| dev_warn(&vdev->dev, "config changed\n"); |
| } |
| |
| static unsigned int features[] = { |
| VIRTIO_IOMMU_F_MAP_UNMAP, |
| VIRTIO_IOMMU_F_INPUT_RANGE, |
| VIRTIO_IOMMU_F_DOMAIN_RANGE, |
| VIRTIO_IOMMU_F_PROBE, |
| VIRTIO_IOMMU_F_MMIO, |
| VIRTIO_IOMMU_F_BYPASS_CONFIG, |
| }; |
| |
| static struct virtio_device_id id_table[] = { |
| { VIRTIO_ID_IOMMU, VIRTIO_DEV_ANY_ID }, |
| { 0 }, |
| }; |
| MODULE_DEVICE_TABLE(virtio, id_table); |
| |
| static struct virtio_driver virtio_iommu_drv = { |
| .driver.name = KBUILD_MODNAME, |
| .driver.owner = THIS_MODULE, |
| .id_table = id_table, |
| .feature_table = features, |
| .feature_table_size = ARRAY_SIZE(features), |
| .probe = viommu_probe, |
| .remove = viommu_remove, |
| .config_changed = viommu_config_changed, |
| }; |
| |
| module_virtio_driver(virtio_iommu_drv); |
| |
| MODULE_DESCRIPTION("Virtio IOMMU driver"); |
| MODULE_AUTHOR("Jean-Philippe Brucker <jean-philippe.brucker@arm.com>"); |
| MODULE_LICENSE("GPL v2"); |