Commit 567f6a6e authored by Nicolas Saenz Julienne's avatar Nicolas Saenz Julienne Committed by Christoph Hellwig
Browse files

dma-direct: provide function to check physical memory area validity 



dma_coherent_ok() checks if a physical memory area fits a device's DMA
constraints.

Signed-off-by: default avatarNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 0dc589da

include/linux/dma-direct.h

+1 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size, 
u64 dma_direct_get_required_mask(struct device *dev);

gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,

				  u64 *phys_mask);

bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size);

void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,

		gfp_t gfp, unsigned long attrs);

void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,

kernel/dma/direct.c

+1 −1
Original line number Diff line number Diff line
@@ -70,7 +70,7 @@ gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask, 
	return 0;

}



static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)

bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)

{

	return phys_to_dma_direct(dev, phys) + size - 1 <=

			min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);