From: Leon Romanovsky <leonro@nvidia.com>

Combine iommu_dma_*map_phys with iommu_dma_*map_resource interfaces in
order to allow single phys_addr_t flow.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/iommu/dma-iommu.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 11c5d5f8c0981..0a19ce50938b3 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1193,12 +1193,17 @@ static inline size_t iova_unaligned(struct iova_domain *iovad, phys_addr_t phys,
 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)
 {
-	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);
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
 	struct iova_domain *iovad = &cookie->iovad;
 	dma_addr_t iova, dma_mask = dma_get_mask(dev);
+	bool coherent;
+	int prot;
+
+	if (attrs & DMA_ATTR_MMIO)
+		return __iommu_dma_map(dev, phys, size,
+				dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO,
+				dma_get_mask(dev));
 
 	/*
 	 * If both the physical buffer start address and size are page aligned,
@@ -1211,6 +1216,9 @@ dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
 			return DMA_MAPPING_ERROR;
 	}
 
+	coherent = dev_is_dma_coherent(dev);
+	prot = dma_info_to_prot(dir, coherent, attrs);
+
 	if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		arch_sync_dma_for_device(phys, size, dir);
 
@@ -1223,10 +1231,14 @@ dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
 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);
 	phys_addr_t phys;
 
-	phys = iommu_iova_to_phys(domain, dma_handle);
+	if (attrs & DMA_ATTR_MMIO) {
+		__iommu_dma_unmap(dev, dma_handle, size);
+		return;
+	}
+
+	phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dma_handle);
 	if (WARN_ON(!phys))
 		return;
 
-- 
2.50.1

On Mon, Aug 04, 2025 at 03:42:40PM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>
> 
> Combine iommu_dma_*map_phys with iommu_dma_*map_resource interfaces in
> order to allow single phys_addr_t flow.

Some later patch deletes iommu_dma_map_resource() ? Mention that plan here?

> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -1193,12 +1193,17 @@ static inline size_t iova_unaligned(struct iova_domain *iovad, phys_addr_t phys,
>  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)
>  {
> -	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);
>  	struct iommu_dma_cookie *cookie = domain->iova_cookie;
>  	struct iova_domain *iovad = &cookie->iovad;
>  	dma_addr_t iova, dma_mask = dma_get_mask(dev);
> +	bool coherent;
> +	int prot;
> +
> +	if (attrs & DMA_ATTR_MMIO)
> +		return __iommu_dma_map(dev, phys, size,
> +				dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO,
> +				dma_get_mask(dev));

I realize that iommu_dma_map_resource() doesn't today, but shouldn't
this be checking for swiotlb:

	if (dev_use_swiotlb(dev, size, dir) &&
	    iova_unaligned(iovad, phys, size)) {

Except we have to fail for ATTR_MMIO?

Now that we have ATTR_MMIO, should dma_info_to_prot() just handle it
directly instead of open coding the | IOMMU_MMIO and messing with the
coherent attribute?

Jason