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swiotlb: add common swiotlb_map_ops

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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>
Acked-by: Christian König <christian.koenig@amd.com>
This commit is contained in:
Christoph Hellwig 2018-01-09 16:44:16 +01:00
parent 7f2c8bbd32
commit 251533eb35
2 changed files with 51 additions and 0 deletions
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8
include/linux/swiotlb.h
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@ -66,6 +66,12 @@ extern void swiotlb_tbl_sync_single(struct device *hwdev,
enum dma_sync_target target); enum dma_sync_target target);
/* Accessory functions. */ /* 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 extern void
*swiotlb_alloc_coherent(struct device *hwdev, size_t size, *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags); 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 int is_swiotlb_buffer(phys_addr_t paddr);
extern void swiotlb_set_max_segment(unsigned int); extern void swiotlb_set_max_segment(unsigned int);
extern const struct dma_map_ops swiotlb_dma_ops;
#endif /* __LINUX_SWIOTLB_H */ #endif /* __LINUX_SWIOTLB_H */

43
lib/swiotlb.c
View File

@ -1087,3 +1087,46 @@ swiotlb_dma_supported(struct device *hwdev, u64 mask)
return swiotlb_phys_to_dma(hwdev, io_tlb_end - 1) <= mask; return swiotlb_phys_to_dma(hwdev, io_tlb_end - 1) <= mask;
} }
EXPORT_SYMBOL(swiotlb_dma_supported); 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 */