On 2023/6/27 15:54, Tian, Kevin wrote:
From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>
Sent: Tuesday, June 13, 2023 11:15 AM
On 6/12/23 4:28 PM, Liu, Jingqi wrote:
On 6/7/2023 11:51 AM, Lu Baolu wrote:
-
- BUG_ON(!domain->pgsize_bitmap);
-
- pg_size = 1UL << __ffs(domain->pgsize_bitmap);
+ pg_size = domain->pgsize_bitmap ? 1UL <<
__ffs(domain->pgsize_bitmap) : 0;
Would it be better to add the following check here?
if (WARN_ON(!pg_size))
return -EINVAL;
Instead of checking latter in the loop as follows.
if (WARN_ON_ONCE(!pg_size)) {
ret = -EINVAL;
goto out;
}
I am afraid no. Only the paging domains need a valid pg_size. That's the
reason why I put it after the iommu_is_dma_domain() check. The previous
code has the same behavior too.
You could also add the dma domain check here. pg_size is static
then it makes more sense to verify it once instead of in a loop.
Agreed. Does below additional change make sense?
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index e59de7852067..3be88b5f36bb 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -962,6 +962,9 @@ static int
iommu_create_device_direct_mappings(struct iommu_domain *domain,
pg_size = domain->pgsize_bitmap ? 1UL <<
__ffs(domain->pgsize_bitmap) : 0;
INIT_LIST_HEAD(&mappings);
+ if (WARN_ON_ONCE((domain->type & __IOMMU_DOMAIN_PAGING) &&
!pg_size))
+ return -EINVAL;
+
iommu_get_resv_regions(dev, &mappings);
/* We need to consider overlapping regions for different devices */
@@ -977,11 +980,6 @@ static int
iommu_create_device_direct_mappings(struct iommu_domain *domain,
!iommu_is_dma_domain(domain))
continue;
- if (WARN_ON_ONCE(!pg_size)) {
- ret = -EINVAL;
- goto out;
- }
-
start = ALIGN(entry->start, pg_size);
end = ALIGN(entry->start + entry->length, pg_size);
Best regards,
baolu
