[PATCH v7 06/15] iommu: Split 'addr_merge' argument to iommu_pgsize() into separate parts

From: Georgi Djakov
Date: Wed Jun 16 2021 - 09:40:08 EST


From: Will Deacon <will@xxxxxxxxxx>

The 'addr_merge' parameter to iommu_pgsize() is a fabricated address
intended to describe the alignment requirements to consider when
choosing an appropriate page size. On the iommu_map() path, this address
is the logical OR of the virtual and physical addresses.

Subsequent improvements to iommu_pgsize() will need to check the
alignment of the virtual and physical components of 'addr_merge'
independently, so pass them in as separate parameters and reconstruct
'addr_merge' locally.

No functional change.

Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Isaac J. Manjarres <isaacm@xxxxxxxxxxxxxx>
Signed-off-by: Georgi Djakov <quic_c_gdjako@xxxxxxxxxxx>
---
drivers/iommu/iommu.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 80e471ada358..80e14c139d40 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2375,12 +2375,13 @@ phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)
}
EXPORT_SYMBOL_GPL(iommu_iova_to_phys);

-static size_t iommu_pgsize(struct iommu_domain *domain,
- unsigned long addr_merge, size_t size)
+static size_t iommu_pgsize(struct iommu_domain *domain, unsigned long iova,
+ phys_addr_t paddr, size_t size)
{
unsigned int pgsize_idx;
unsigned long pgsizes;
size_t pgsize;
+ unsigned long addr_merge = paddr | iova;

/* Page sizes supported by the hardware and small enough for @size */
pgsizes = domain->pgsize_bitmap & GENMASK(__fls(size), 0);
@@ -2433,7 +2434,7 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
pr_debug("map: iova 0x%lx pa %pa size 0x%zx\n", iova, &paddr, size);

while (size) {
- size_t pgsize = iommu_pgsize(domain, iova | paddr, size);
+ size_t pgsize = iommu_pgsize(domain, iova, paddr, size);

pr_debug("mapping: iova 0x%lx pa %pa pgsize 0x%zx\n",
iova, &paddr, pgsize);
@@ -2521,8 +2522,9 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
* or we hit an area that isn't mapped.
*/
while (unmapped < size) {
- size_t pgsize = iommu_pgsize(domain, iova, size - unmapped);
+ size_t pgsize;

+ pgsize = iommu_pgsize(domain, iova, iova, size - unmapped);
unmapped_page = ops->unmap(domain, iova, pgsize, iotlb_gather);
if (!unmapped_page)
break;