[PATCH 07/22] swiotlb: add common swiotlb_map_ops
From: hch@lst.de (Christoph Hellwig)
Date: 2018-01-10 08:10:06
Also in:
linux-arch, linux-iommu, linux-mips, linuxppc-dev, lkml
Subsystem:
dma mapping helpers, library code, the rest · Maintainers:
Marek Szyprowski, Andrew Morton, Linus Torvalds
Currently all architectures that want to use swiotlb have to implement their own dma_map_ops instances. Provide a generic one based on the x86 implementation which first calls into dma_direct to try a full blown direct mapping implementation (including e.g. CMA) before falling back allocating from the swiotlb buffer. Signed-off-by: Christoph Hellwig <hch@lst.de> --- include/linux/swiotlb.h | 8 ++++++++ lib/swiotlb.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+)
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 606375e35d87..5b1f2a00491c 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h@@ -66,6 +66,12 @@ extern void swiotlb_tbl_sync_single(struct device *hwdev, enum dma_sync_target target); /* Accessory functions. */ + +void *swiotlb_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle, + gfp_t flags, unsigned long attrs); +void swiotlb_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_addr, unsigned long attrs); + extern void *swiotlb_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags);
@@ -126,4 +132,6 @@ extern void swiotlb_print_info(void); extern int is_swiotlb_buffer(phys_addr_t paddr); extern void swiotlb_set_max_segment(unsigned int); +extern const struct dma_map_ops swiotlb_dma_ops; + #endif /* __LINUX_SWIOTLB_H */
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index cf5311908fa9..0fae2f45c3c0 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c@@ -1087,3 +1087,46 @@ swiotlb_dma_supported(struct device *hwdev, u64 mask) return swiotlb_phys_to_dma(hwdev, io_tlb_end - 1) <= mask; } EXPORT_SYMBOL(swiotlb_dma_supported); + +#ifdef CONFIG_DMA_DIRECT_OPS +void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t gfp, unsigned long attrs) +{ + void *vaddr; + + /* + * Don't print a warning when the first allocation attempt fails. + * swiotlb_alloc_coherent() will print a warning when the DMA memory + * allocation ultimately failed. + */ + gfp |= __GFP_NOWARN; + + vaddr = dma_direct_alloc(dev, size, dma_handle, gfp, attrs); + if (!vaddr) + vaddr = swiotlb_alloc_coherent(dev, size, dma_handle, gfp); + return vaddr; +} + +void swiotlb_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_addr, unsigned long attrs) +{ + if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr))) + swiotlb_free_coherent(dev, size, vaddr, dma_addr); + else + dma_direct_free(dev, size, vaddr, dma_addr, attrs); +} + +const struct dma_map_ops swiotlb_dma_ops = { + .mapping_error = swiotlb_dma_mapping_error, + .alloc = swiotlb_alloc, + .free = swiotlb_free, + .sync_single_for_cpu = swiotlb_sync_single_for_cpu, + .sync_single_for_device = swiotlb_sync_single_for_device, + .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = swiotlb_sync_sg_for_device, + .map_sg = swiotlb_map_sg_attrs, + .unmap_sg = swiotlb_unmap_sg_attrs, + .map_page = swiotlb_map_page, + .unmap_page = swiotlb_unmap_page, +}; +#endif /* CONFIG_DMA_DIRECT_OPS */
--
2.14.2