Commit f9374de1 authored by Leon Romanovsky's avatar Leon Romanovsky Committed by Marek Szyprowski
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iommu/dma: implement DMA_ATTR_MMIO for iommu_dma_(un)map_phys() 



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: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/acc255bee358fec9c7da6b2a5904ee50abcd09f1.1757423202.git.leonro@nvidia.com
parent 513559f7

drivers/iommu/dma-iommu.c

+11 −4
Original line number Diff line number Diff line
@@ -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;