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Almost all instances of the dma_map_ops ->map_page()/map_sg() methods implement ->unmap_page()/unmap_sg() too. The once instance which doesn't dma_dummy_ops which is used to fail the DMA mapping and thus there won't be any calls to ->unmap_page()/unmap_sg(). Remove the checks for ->unmap_page()/unmap_sg() and call them directly to create an interface that is symmetrical to ->map_page()/map_sg(). Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Leon Romanovsky <leon@kernel.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
60 lines
1.5 KiB
C
60 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Dummy DMA ops that always fail.
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*/
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#include <linux/dma-map-ops.h>
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static int dma_dummy_mmap(struct device *dev, struct vm_area_struct *vma,
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void *cpu_addr, dma_addr_t dma_addr, size_t size,
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unsigned long attrs)
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{
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return -ENXIO;
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}
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static dma_addr_t dma_dummy_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size, enum dma_data_direction dir,
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unsigned long attrs)
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{
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return DMA_MAPPING_ERROR;
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}
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static void dma_dummy_unmap_page(struct device *dev, dma_addr_t dma_handle,
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size_t size, enum dma_data_direction dir, unsigned long attrs)
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{
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/*
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* Dummy ops doesn't support map_page, so unmap_page should never be
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* called.
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*/
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WARN_ON_ONCE(true);
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}
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static int dma_dummy_map_sg(struct device *dev, struct scatterlist *sgl,
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int nelems, enum dma_data_direction dir,
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unsigned long attrs)
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{
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return -EINVAL;
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}
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static void dma_dummy_unmap_sg(struct device *dev, struct scatterlist *sgl,
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int nelems, enum dma_data_direction dir,
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unsigned long attrs)
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{
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/*
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* Dummy ops doesn't support map_sg, so unmap_sg should never be called.
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*/
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WARN_ON_ONCE(true);
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}
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static int dma_dummy_supported(struct device *hwdev, u64 mask)
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{
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return 0;
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}
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const struct dma_map_ops dma_dummy_ops = {
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.mmap = dma_dummy_mmap,
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.map_page = dma_dummy_map_page,
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.unmap_page = dma_dummy_unmap_page,
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.map_sg = dma_dummy_map_sg,
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.unmap_sg = dma_dummy_unmap_sg,
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.dma_supported = dma_dummy_supported,
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};
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