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iommu/dma: implement DMA_ATTR_MMIO for iommu_dma_(un)map_phys()

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Make iommu_dma_map_phys() and iommu_dma_unmap_phys() respect
DMA_ATTR_MMIO.

DMA_ATTR_MMIO makes the functions behave the same as
iommu_dma_(un)map_resource():
 - No swiotlb is possible
 - No cache flushing is done (ATTR_MMIO should not be cached memory)
 - prot for iommu_map() has IOMMU_MMIO not IOMMU_CACHE

This is preparation for replacing iommu_dma_map_resource() callers
with iommu_dma_map_phys(DMA_ATTR_MMIO) and removing
iommu_dma_(un)map_resource().

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/acc255bee358fec9c7da6b2a5904ee50abcd09f1.1757423202.git.leonro@nvidia.com
This commit is contained in:
Leon Romanovsky
2025-09-09 16:27:34 +03:00
committed by Marek Szyprowski
parent 513559f737
commit f9374de14c
1 changed files with 11 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/iommu/dma-iommu.c
+11 -4
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@@ -1211,16 +1211,19 @@ dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
*/
if (dev_use_swiotlb(dev, size, dir) &&
iova_unaligned(iovad, phys, size)) {
if (attrs & DMA_ATTR_MMIO)
return DMA_MAPPING_ERROR;
phys = iommu_dma_map_swiotlb(dev, phys, size, dir, attrs);
if (phys == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;
}
if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
if (!coherent && !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO)))
arch_sync_dma_for_device(phys, size, dir);
iova = __iommu_dma_map(dev, phys, size, prot, dma_mask);
if (iova == DMA_MAPPING_ERROR)
if (iova == DMA_MAPPING_ERROR && !(attrs & DMA_ATTR_MMIO))
swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs);
return iova;
}
@@ -1228,10 +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;