Attaching an IOMMU domain to a PASID of a device is a generic operation
for modern IOMMU drivers which support PASID-granular DMA address
translation. Currently visible usage scenarios include (but not limited):
- SVA (Shared Virtual Address)
- kernel DMA with PASID
- hardware-assist mediated device
This adds a pair of common domain ops for this purpose and adds helpers
to attach/detach a domain to/from a {device, PASID}.
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
---
include/linux/iommu.h | 21 +++++++++++++++++++
drivers/iommu/iommu.c | 48 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 69 insertions(+)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 36f43af0af53..fe7d9ee2bc2b 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -262,6 +262,8 @@ struct iommu_ops {
* struct iommu_domain_ops - domain specific operations
* @attach_dev: attach an iommu domain to a device
* @detach_dev: detach an iommu domain from a device
+ * @attach_dev_pasid: attach an iommu domain to a pasid of device
+ * @detach_dev_pasid: detach an iommu domain from a pasid of device
* @map: map a physically contiguous memory region to an iommu domain
* @map_pages: map a physically contiguous set of pages of the same size to
* an iommu domain.
@@ -279,6 +281,10 @@ struct iommu_ops {
struct iommu_domain_ops {
int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
+ int (*attach_dev_pasid)(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid);
+ void (*detach_dev_pasid)(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid);
int (*map)(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
@@ -672,6 +678,10 @@ int iommu_group_claim_dma_owner(struct iommu_group *group,
void *owner);
void iommu_group_release_dma_owner(struct iommu_group *group);
bool iommu_group_dma_owner_claimed(struct iommu_group *group);
+int iommu_attach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid);
+void iommu_detach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid);
#else /* CONFIG_IOMMU_API */
struct iommu_ops {};
@@ -1040,6 +1050,17 @@ static inline bool iommu_group_dma_owner_claimed(struct
iommu_group *group)
{
return false;
}
+
+static inline int iommu_attach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
+{
+ return -ENODEV;
+}
+
+static inline void iommu_detach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
+{
+}
#endif /* CONFIG_IOMMU_API */
/**
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 56ffbf5fdc18..63f880dd0c80 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -38,6 +38,7 @@ struct iommu_group {
struct kobject kobj;
struct kobject *devices_kobj;
struct list_head devices;
+ struct xarray pasid_array;
struct mutex mutex;
void *iommu_data;
void (*iommu_data_release)(void *iommu_data);
@@ -642,6 +643,7 @@ struct iommu_group *iommu_group_alloc(void)
mutex_init(&group->mutex);
INIT_LIST_HEAD(&group->devices);
INIT_LIST_HEAD(&group->entry);
+ xa_init(&group->pasid_array);
ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL);
if (ret < 0) {
@@ -3214,3 +3216,49 @@ bool iommu_group_dma_owner_claimed(struct iommu_group
*group)
return user;
}
EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed);
+
+int iommu_attach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
+{
+ struct iommu_group *group;
+ int ret = -EINVAL;
+ void *curr;
+
+ if (!domain->ops->attach_dev_pasid)
+ return -EINVAL;
+
+ group = iommu_group_get(dev);
+ if (!group)
+ return -ENODEV;
+
+ mutex_lock(&group->mutex);
+ if (!group->immutable_singleton)
+ goto out_unlock;
+
+ curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL);
+ if (curr)
+ goto out_unlock;
+
+ ret = domain->ops->attach_dev_pasid(domain, dev, pasid);
+ if (ret)
+ xa_erase(&group->pasid_array, pasid);
+
+out_unlock:
+ mutex_unlock(&group->mutex);
+ iommu_group_put(group);
+
+ return ret;
+}
+
+void iommu_detach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
+{
+ struct iommu_group *group = iommu_group_get(dev);
+
+ mutex_lock(&group->mutex);
+ domain->ops->detach_dev_pasid(domain, dev, pasid);
+ xa_erase(&group->pasid_array, pasid);
+ mutex_unlock(&group->mutex);
+
+ iommu_group_put(group);
+}
--
2.25.1
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