__IOMMU_DOMAIN_LARGE_PAGES indicates that a domain can handle
conditions where PAGE_SIZE might be smaller than the IOMMU page size.
Always allow attaching devices to such domains and set the flag for
IOMMU_DOMAIN_DMA, which can now handle these situations.
Signed-off-by: Sven Peter <s...@svenpeter.dev>
---
drivers/iommu/iommu.c | 2 ++
include/linux/iommu.h | 14 +++++++++-----
2 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5854a4ef5681..f0bfd76187b1 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1970,6 +1970,8 @@ static int iommu_check_page_size(struct iommu_domain
*domain)
{
if (!(domain->type & __IOMMU_DOMAIN_PAGING))
return 0;
+ if (domain->type & __IOMMU_DOMAIN_LARGE_PAGES)
+ return 0;
if ((1 << __ffs(domain->pgsize_bitmap)) > PAGE_SIZE) {
pr_warn("IOMMU page size cannot represent CPU pages.\n");
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index e552ecfefcf7..1f97eac8a4b0 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -56,10 +56,13 @@ struct iommu_domain_geometry {
};
/* Domain feature flags */
-#define __IOMMU_DOMAIN_PAGING (1U << 0) /* Support for iommu_map/unmap */
-#define __IOMMU_DOMAIN_DMA_API (1U << 1) /* Domain for use in DMA-API
- implementation */
-#define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */
+#define __IOMMU_DOMAIN_PAGING (1U << 0) /* Support for iommu_map/unmap
*/
+#define __IOMMU_DOMAIN_DMA_API (1U << 1) /* Domain for use in DMA-API
+ implementation
*/
+#define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped
*/
+#define __IOMMU_DOMAIN_LARGE_PAGES (1U << 3) /* Domain can handle IOMMU page
+ sizes larger than the CPU
+ page size */
/*
* This are the possible domain-types
@@ -77,7 +80,8 @@ struct iommu_domain_geometry {
#define IOMMU_DOMAIN_IDENTITY (__IOMMU_DOMAIN_PT)
#define IOMMU_DOMAIN_UNMANAGED (__IOMMU_DOMAIN_PAGING)
#define IOMMU_DOMAIN_DMA (__IOMMU_DOMAIN_PAGING | \
- __IOMMU_DOMAIN_DMA_API)
+ __IOMMU_DOMAIN_DMA_API | \
+ __IOMMU_DOMAIN_LARGE_PAGES)
struct iommu_domain {
unsigned type;
--
2.25.1
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