blob: 8b1b5c270e502c5c15b48e88ffc6fb346f0818e4 [file] [log] [blame]
// 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_platform.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[];
};
#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,
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(&region->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_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;
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);
else if (mapped)
*mapped = size;
return ret;
}
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 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);
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:
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 viommu_endpoint *vdev = dev_iommu_priv_get(dev);
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 bool viommu_capable(struct device *dev, enum iommu_cap cap)
{
switch (cap) {
case IOMMU_CAP_CACHE_COHERENCY:
return true;
default:
return false;
}
}
static struct iommu_ops viommu_ops = {
.capable = viommu_capable,
.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,
.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,
.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);
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,
.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");