[PATCH v6 04/15] iommu: Add a map_pages() op for IOMMU drivers

From: Georgi Djakov
Date: Tue Jun 15 2021 - 13:09:02 EST


From: "Isaac J. Manjarres" <isaacm@xxxxxxxxxxxxxx>

Add a callback for IOMMU drivers to provide a path for the
IOMMU framework to call into an IOMMU driver, which can
call into the io-pgtable code, to map a physically contiguous
rnage of pages of the same size.

For IOMMU drivers that do not specify a map_pages() callback,
the existing logic of mapping memory one page block at a time
will be used.

Signed-off-by: Isaac J. Manjarres <isaacm@xxxxxxxxxxxxxx>
Suggested-by: Will Deacon <will@xxxxxxxxxx>
Acked-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Georgi Djakov <quic_c_gdjako@xxxxxxxxxxx>
---
include/linux/iommu.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 25a844121be5..d7989d4a7404 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -180,6 +180,8 @@ struct iommu_iotlb_gather {
* @attach_dev: attach device to an iommu domain
* @detach_dev: detach device from an iommu domain
* @map: map a physically contiguous memory region to an iommu domain
+ * @map_pages: map a physically contiguous set of pages of the same size to
+ * an iommu domain.
* @unmap: unmap a physically contiguous memory region from an iommu domain
* @unmap_pages: unmap a number of pages of the same size from an iommu domain
* @flush_iotlb_all: Synchronously flush all hardware TLBs for this domain
@@ -230,6 +232,9 @@ struct iommu_ops {
void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
int (*map)(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
+ int (*map_pages)(struct iommu_domain *domain, unsigned long iova,
+ phys_addr_t paddr, size_t pgsize, size_t pgcount,
+ int prot, gfp_t gfp, size_t *mapped);
size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
size_t size, struct iommu_iotlb_gather *iotlb_gather);
size_t (*unmap_pages)(struct iommu_domain *domain, unsigned long iova,