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-rw-r--r--drivers/iommu/iommu-sva.c17
-rw-r--r--include/linux/iommu.h3
2 files changed, 20 insertions, 0 deletions
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index c3fc9201d0be..7f91c8d0064b 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -41,6 +41,7 @@ static struct iommu_mm_data *iommu_alloc_mm_data(struct mm_struct *mm, struct de
}
iommu_mm->pasid = pasid;
INIT_LIST_HEAD(&iommu_mm->sva_domains);
+ INIT_LIST_HEAD(&iommu_mm->sva_handles);
/*
* Make sure the write to mm->iommu_mm is not reordered in front of
* initialization to iommu_mm fields. If it does, readers may see a
@@ -82,6 +83,14 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
goto out_unlock;
}
+ list_for_each_entry(handle, &mm->iommu_mm->sva_handles, handle_item) {
+ if (handle->dev == dev) {
+ refcount_inc(&handle->users);
+ mutex_unlock(&iommu_sva_lock);
+ return handle;
+ }
+ }
+
handle = kzalloc(sizeof(*handle), GFP_KERNEL);
if (!handle) {
ret = -ENOMEM;
@@ -108,7 +117,9 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
if (ret)
goto out_free_domain;
domain->users = 1;
+ refcount_set(&handle->users, 1);
list_add(&domain->next, &mm->iommu_mm->sva_domains);
+ list_add(&handle->handle_item, &mm->iommu_mm->sva_handles);
out:
mutex_unlock(&iommu_sva_lock);
@@ -141,6 +152,12 @@ void iommu_sva_unbind_device(struct iommu_sva *handle)
struct device *dev = handle->dev;
mutex_lock(&iommu_sva_lock);
+ if (!refcount_dec_and_test(&handle->users)) {
+ mutex_unlock(&iommu_sva_lock);
+ return;
+ }
+ list_del(&handle->handle_item);
+
iommu_detach_device_pasid(domain, dev, iommu_mm->pasid);
if (--domain->users == 0) {
list_del(&domain->next);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 1ea2a820e1eb..5e27cb3a3be9 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -892,11 +892,14 @@ struct iommu_fwspec {
struct iommu_sva {
struct device *dev;
struct iommu_domain *domain;
+ struct list_head handle_item;
+ refcount_t users;
};
struct iommu_mm_data {
u32 pasid;
struct list_head sva_domains;
+ struct list_head sva_handles;
};
int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,