[PATCH v6 05/16] iommu/dma: rename iommu_dma_*map_page to iommu_dma_*map_phys

Leon Romanovsky
2025-09-09T13:28:48Z

Rename the IOMMU DMA mapping functions to better reflect their actual
calling convention. The functions iommu_dma_map_page() and
iommu_dma_unmap_page() are renamed to iommu_dma_map_phys() and
iommu_dma_unmap_phys() respectively, as they already operate on physical
addresses rather than page structures.

The calling convention changes from accepting (struct page *page,
unsigned long offset) to (phys_addr_t phys), which eliminates the need
for page-to-physical address conversion within the functions. This
renaming prepares for the broader DMA API conversion from page-based
to physical address-based mapping throughout the kernel.

All callers are updated to pass physical addresses directly, including
dma_map_page_attrs(), scatterlist mapping functions, and DMA page
allocation helpers. The change simplifies the code by removing the
page_to_phys() + offset calculation that was previously done inside
the IOMMU functions.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
drivers/iommu/dma-iommu.c | 14 ++++++--------
include/linux/iommu-dma.h | 7 +++----
kernel/dma/mapping.c | 4 ++--
kernel/dma/ops_helpers.c | 6 +++---
4 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index e1185ba73e23a..aea119f32f965 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1195,11 +1195,9 @@ static inline size_t iova_unaligned(struct iova_domain *iovad, phys_addr_t phys,
return iova_offset(iovad, phys | size);
}

-dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size, enum dma_data_direction dir,
- unsigned long attrs)
+dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
+ enum dma_data_direction dir, unsigned long attrs)
{
- phys_addr_t phys = page_to_phys(page) + offset;
bool coherent = dev_is_dma_coherent(dev);
int prot = dma_info_to_prot(dir, coherent, attrs);
struct iommu_domain *domain = iommu_get_dma_domain(dev);
@@ -1227,7 +1225,7 @@ dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
return iova;
}

-void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
+void iommu_dma_unmap_phys(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
struct iommu_domain *domain = iommu_get_dma_domain(dev);
@@ -1346,7 +1344,7 @@ static void iommu_dma_unmap_sg_swiotlb(struct device *dev, struct scatterlist *s
int i;

for_each_sg(sg, s, nents, i)
- iommu_dma_unmap_page(dev, sg_dma_address(s),
+ iommu_dma_unmap_phys(dev, sg_dma_address(s),
sg_dma_len(s), dir, attrs);
}

@@ -1359,8 +1357,8 @@ static int iommu_dma_map_sg_swiotlb(struct device *dev, struct scatterlist *sg,
sg_dma_mark_swiotlb(sg);

for_each_sg(sg, s, nents, i) {
- sg_dma_address(s) = iommu_dma_map_page(dev, sg_page(s),
- s->offset, s->length, dir, attrs);
+ sg_dma_address(s) = iommu_dma_map_phys(dev, sg_phys(s),
+ s->length, dir, attrs);
if (sg_dma_address(s) == DMA_MAPPING_ERROR)
goto out_unmap;
sg_dma_len(s) = s->length;
diff --git a/include/linux/iommu-dma.h b/include/linux/iommu-dma.h
index 508beaa44c39e..485bdffed9888 100644
--- a/include/linux/iommu-dma.h
+++ b/include/linux/iommu-dma.h
@@ -21,10 +21,9 @@ static inline bool use_dma_iommu(struct device *dev)
}
#endif /* CONFIG_IOMMU_DMA */

-dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size, enum dma_data_direction dir,
- unsigned long attrs);
-void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
+dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
+ enum dma_data_direction dir, unsigned long attrs);
+void iommu_dma_unmap_phys(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir, unsigned long attrs);
int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir, unsigned long attrs);
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index bd3bb6d59d722..90ad728205b93 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -169,7 +169,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
arch_dma_map_page_direct(dev, phys + size))
addr = dma_direct_map_page(dev, page, offset, size, dir, attrs);
else if (use_dma_iommu(dev))
- addr = iommu_dma_map_page(dev, page, offset, size, dir, attrs);
+ addr = iommu_dma_map_phys(dev, phys, size, dir, attrs);
else
addr = ops->map_page(dev, page, offset, size, dir, attrs);
kmsan_handle_dma(page, offset, size, dir);
@@ -190,7 +190,7 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
arch_dma_unmap_page_direct(dev, addr + size))
dma_direct_unmap_page(dev, addr, size, dir, attrs);
else if (use_dma_iommu(dev))
- iommu_dma_unmap_page(dev, addr, size, dir, attrs);
+ iommu_dma_unmap_phys(dev, addr, size, dir, attrs);
else
ops->unmap_page(dev, addr, size, dir, attrs);
trace_dma_unmap_phys(dev, addr, size, dir, attrs);
diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c
index 9afd569eadb96..6f9d604d9d406 100644
--- a/kernel/dma/ops_helpers.c
+++ b/kernel/dma/ops_helpers.c
@@ -72,8 +72,8 @@ struct page *dma_common_alloc_pages(struct device *dev, size_t size,
return NULL;

if (use_dma_iommu(dev))
- *dma_handle = iommu_dma_map_page(dev, page, 0, size, dir,
- DMA_ATTR_SKIP_CPU_SYNC);
+ *dma_handle = iommu_dma_map_phys(dev, page_to_phys(page), size,
+ dir, DMA_ATTR_SKIP_CPU_SYNC);
else
*dma_handle = ops->map_page(dev, page, 0, size, dir,
DMA_ATTR_SKIP_CPU_SYNC);
@@ -92,7 +92,7 @@ void dma_common_free_pages(struct device *dev, size_t size, struct page *page,
const struct dma_map_ops *ops = get_dma_ops(dev);

if (use_dma_iommu(dev))
- iommu_dma_unmap_page(dev, dma_handle, size, dir,
+ iommu_dma_unmap_phys(dev, dma_handle, size, dir,
DMA_ATTR_SKIP_CPU_SYNC);
else if (ops->unmap_page)
ops->unmap_page(dev, dma_handle, size, dir,
--
2.51.0