dma-coherent: add documentation to new interfaces (b6d4f7e3) · Commits · e / devices / android_kernel_fairphone_FP4

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;