Commit b6d4f7e3 authored by Dmitry Eremin-Solenikov's avatar Dmitry Eremin-Solenikov Committed by Ingo Molnar
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dma-coherent: add documentation to new interfaces 



Signed-off-by: default avatarDmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 8fa8b9fb

kernel/dma-coherent.c

+28 −0
Original line number Diff line number Diff line
@@ -92,6 +92,21 @@ void *dma_mark_declared_memory_occupied(struct device *dev, 
}

EXPORT_SYMBOL(dma_mark_declared_memory_occupied);



/**

 * Try to allocate memory from the per-device coherent area.

 *

 * @dev:	device from which we allocate memory

 * @size:	size of requested memory area

 * @dma_handle:	This will be filled with the correct dma handle

 * @ret:	This pointer will be filled with the virtual address

 * 		to allocated area.

 *

 * This function should be only called from per-arch %dma_alloc_coherent()

 * to support allocation from per-device coherent memory pools.

 *

 * Returns 0 if dma_alloc_coherent should continue with allocating from

 * generic memory areas, or !0 if dma_alloc_coherent should return %ret.

 */

int dma_alloc_from_coherent(struct device *dev, ssize_t size,

				       dma_addr_t *dma_handle, void **ret)

{
@@ -111,6 +126,19 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size, 
	return (mem != NULL);

}



/**

 * Try to free the memory allocated from per-device coherent memory pool.

 * @dev:	device from which the memory was allocated

 * @order:	the order of pages allocated

 * @vaddr:	virtual address of allocated pages

 *

 * This checks whether the memory was allocated from the per-device

 * coherent memory pool and if so, releases that memory.

 *

 * Returns 1 if we correctly released the memory, or 0 if

 * %dma_release_coherent() should proceed with releasing memory from

 * generic pools.

 */

int dma_release_from_coherent(struct device *dev, int order, void *vaddr)

{

	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;