iommu: Allow selecting page sizes per domain
Many IOMMUs support multiple page table formats, meaning that any given
domain may only support a subset of the hardware page sizes presented in
iommu_ops->pgsize_bitmap. There are also certain use-cases where the
creator of a domain may want to control which page sizes are used, for
example to force the use of hugepage mappings to reduce pagetable walk
depth.
To this end, add a per-domain pgsize_bitmap to represent the subset of
page sizes actually in use, to make it possible for domains with
different requirements to coexist.
Signed-off-by: Will Deacon <will.deacon@arm.com>
[rm: hijacked and rebased original patch with new commit message]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 8a25704..7811294 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -78,6 +78,7 @@
struct iommu_domain {
unsigned type;
const struct iommu_ops *ops;
+ unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */
iommu_fault_handler_t handler;
void *handler_token;
struct iommu_domain_geometry geometry;
@@ -155,7 +156,7 @@
* @domain_set_windows: Set the number of windows for a domain
* @domain_get_windows: Return the number of windows for a domain
* @of_xlate: add OF master IDs to iommu grouping
- * @pgsize_bitmap: bitmap of supported page sizes
+ * @pgsize_bitmap: bitmap of all possible supported page sizes
*/
struct iommu_ops {
bool (*capable)(enum iommu_cap);