swiotlb: add common swiotlb_map_ops

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

View file

@ -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 */