// 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/delay.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.h> #include <linux/pci.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> #include "dma-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[] __counted_by(len); }; #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(struct_size(req, buf, 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, GFP_KERNEL); break; case VIRTIO_IOMMU_RESV_MEM_T_MSI: region = iommu_alloc_resv_region(start, size, prot, IOMMU_RESV_MSI, GFP_KERNEL); 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 -ENODEV; } 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 ret; } } 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) { ret = -EINVAL; } 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 void viommu_detach_dev(struct viommu_endpoint *vdev) { int i; struct virtio_iommu_req_detach req; struct viommu_domain *vdomain = vdev->vdomain; struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(vdev->dev); if (!vdomain) return; req = (struct virtio_iommu_req_detach) { .head.type = VIRTIO_IOMMU_T_DETACH, .domain = cpu_to_le32(vdomain->id), }; for (i = 0; i < fwspec->num_ids; i++) { req.endpoint = cpu_to_le32(fwspec->ids[i]); WARN_ON(viommu_send_req_sync(vdev->viommu, &req, sizeof(req))); } vdomain->nr_endpoints--; vdev->vdomain = NULL; } static int viommu_map_pages(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t pgsize, size_t pgcount, int prot, gfp_t gfp, size_t *mapped) { int ret; u32 flags; size_t size = pgsize * pgcount; 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; if (vdomain->nr_endpoints) { 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), }; ret = viommu_add_req(vdomain->viommu, &map, sizeof(map)); if (ret) { viommu_del_mappings(vdomain, iova, end); return ret; } } if (mapped) *mapped = size; return 0; } static size_t viommu_unmap_pages(struct iommu_domain *domain, unsigned long iova, size_t pgsize, size_t pgcount, 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); size_t size = pgsize * pgcount; 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 int viommu_iotlb_sync_map(struct iommu_domain *domain, unsigned long iova, size_t size) { struct viommu_domain *vdomain = to_viommu_domain(domain); /* * May be called before the viommu is initialized including * while creating direct mapping */ if (!vdomain->nr_endpoints) return 0; return viommu_sync_req(vdomain->viommu); } static void viommu_flush_iotlb_all(struct iommu_domain *domain) { struct viommu_domain *vdomain = to_viommu_domain(domain); /* * May be called before the viommu is initialized including * while creating direct mapping */ if (!vdomain->nr_endpoints) return; 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, GFP_KERNEL); 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 device_match_fwnode(dev->parent, 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); 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: iommu_put_resv_regions(dev, &vdev->resv_regions); kfree(vdev); return ERR_PTR(ret); } static void viommu_release_device(struct device *dev) { struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); viommu_detach_dev(vdev); 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, const struct of_phandle_args *args) { return iommu_fwspec_add_ids(dev, args->args, 1); } static bool viommu_capable(struct device *dev, enum iommu_cap cap) { switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: return true; case IOMMU_CAP_DEFERRED_FLUSH: return true; default: return false; } } static struct iommu_ops viommu_ops = { .capable = viommu_capable, .domain_alloc = viommu_domain_alloc, .probe_device = viommu_probe_device, .release_device = viommu_release_device, .device_group = viommu_device_group, .get_resv_regions = viommu_get_resv_regions, .of_xlate = viommu_of_xlate, .owner = THIS_MODULE, .default_domain_ops = &(const struct iommu_domain_ops) { .attach_dev = viommu_attach_dev, .map_pages = viommu_map_pages, .unmap_pages = viommu_unmap_pages, .iova_to_phys = viommu_iova_to_phys, .flush_iotlb_all = viommu_flush_iotlb_all, .iotlb_sync = viommu_iotlb_sync, .iotlb_sync_map = viommu_iotlb_sync_map, .free = viommu_domain_free, } }; static int viommu_init_vqs(struct viommu_dev *viommu) { struct virtio_device *vdev = dev_to_virtio(viommu->dev); struct virtqueue_info vqs_info[] = { { "request" }, { "event", viommu_event_handler }, }; return virtio_find_vqs(vdev, VIOMMU_NR_VQS, viommu->vqs, vqs_info, 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); 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_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, .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");