From: Leon Romanovsky <[email protected]> Add support for the DMA_ATTR_REQUIRE_COHERENT attribute to the exported functions. This attribute indicates that the SWIOTLB path must not be used and that no sync operations should be performed.
Signed-off-by: Leon Romanovsky <[email protected]> --- drivers/iommu/dma-iommu.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 5dac64be61bb2..94d5141696424 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -1211,7 +1211,7 @@ 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) + if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT)) return DMA_MAPPING_ERROR; phys = iommu_dma_map_swiotlb(dev, phys, size, dir, attrs); @@ -1223,7 +1223,8 @@ dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size, arch_sync_dma_for_device(phys, size, dir); iova = __iommu_dma_map(dev, phys, size, prot, dma_mask); - if (iova == DMA_MAPPING_ERROR && !(attrs & DMA_ATTR_MMIO)) + if (iova == DMA_MAPPING_ERROR && + !(attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))) swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs); return iova; } @@ -1233,7 +1234,7 @@ void iommu_dma_unmap_phys(struct device *dev, dma_addr_t dma_handle, { phys_addr_t phys; - if (attrs & DMA_ATTR_MMIO) { + if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT)) { __iommu_dma_unmap(dev, dma_handle, size); return; } @@ -1945,9 +1946,21 @@ int dma_iova_link(struct device *dev, struct dma_iova_state *state, if (WARN_ON_ONCE(iova_start_pad && offset > 0)) return -EIO; + /* + * DMA_IOVA_USE_SWIOTLB is set on state after some entry + * took SWIOTLB path, which we were supposed to prevent + * for DMA_ATTR_REQUIRE_COHERENT attribute. + */ + if (WARN_ON_ONCE((state->__size & DMA_IOVA_USE_SWIOTLB) && + (attrs & DMA_ATTR_REQUIRE_COHERENT))) + return -EOPNOTSUPP; + + if (!dev_is_dma_coherent(dev) && (attrs & DMA_ATTR_REQUIRE_COHERENT)) + return -EOPNOTSUPP; + if (dev_use_swiotlb(dev, size, dir) && iova_unaligned(iovad, phys, size)) { - if (attrs & DMA_ATTR_MMIO) + if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT)) return -EPERM; return iommu_dma_iova_link_swiotlb(dev, state, phys, offset, -- 2.53.0
