Hi,
On 2021/4/9 1:08, Jacob Pan wrote:
/**
* iommu_sva_alloc_pasid - Allocate a PASID for the mm
- * @mm: the mm
* @min: minimum PASID value (inclusive)
* @max: maximum PASID value (inclusive)
*
- * Try to allocate a PASID for this mm, or take a reference to the existing one
- * provided it fits within the [@min, @max] range. On success the PASID is
- * available in mm->pasid, and must be released with iommu_sva_free_pasid().
+ * Try to allocate a PASID for the current mm, or take a reference to the
+ * existing one provided it fits within the [@min, @max] range. On success
+ * the PASID is available in the current mm->pasid, and must be released with
+ * iommu_sva_free_pasid().
* @min must be greater than 0, because 0 indicates an unused mm->pasid.
*
* Returns 0 on success and < 0 on error.
*/
-int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
+int iommu_sva_alloc_pasid(ioasid_t min, ioasid_t max)
{
int ret = 0;
ioasid_t pasid;
+ struct mm_struct *mm;
if (min == INVALID_IOASID || max == INVALID_IOASID ||
min == 0 || max < min)
return -EINVAL;
mutex_lock(&iommu_sva_lock);
+ mm = get_task_mm(current);
How could we allocate a supervisor PASID through iommu_sva_alloc_pasid()
if we always use current->mm here?
+ if (!mm) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
if (mm->pasid) {
if (mm->pasid >= min && mm->pasid <= max)
ioasid_get(mm->pasid);
@@ -45,22 +51,32 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t
min, ioasid_t max)
else
mm->pasid = pasid;
}
+ mmput(mm);
+out_unlock:
mutex_unlock(&iommu_sva_lock);
return ret;
}
EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);
Best regards,
baolu
