Commit de7cf917 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods 



This will allow IOMMU drivers to allocate non-contigous memory and
return a vmapped virtual address.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent efa70f2f

include/linux/dma-mapping.h

+5 −0
Original line number Diff line number Diff line
@@ -74,6 +74,11 @@ struct dma_map_ops { 
			gfp_t gfp);

	void (*free_pages)(struct device *dev, size_t size, struct page *vaddr,

			dma_addr_t dma_handle, enum dma_data_direction dir);

	void* (*alloc_noncoherent)(struct device *dev, size_t size,

			dma_addr_t *dma_handle, enum dma_data_direction dir,

			gfp_t gfp);

	void (*free_noncoherent)(struct device *dev, size_t size, void *vaddr,

			dma_addr_t dma_handle, enum dma_data_direction dir);

	int (*mmap)(struct device *, struct vm_area_struct *,

			  void *, dma_addr_t, size_t,

			  unsigned long attrs);

kernel/dma/mapping.c

+27 −6
Original line number Diff line number Diff line
@@ -513,6 +513,10 @@ EXPORT_SYMBOL_GPL(dma_free_pages); 
void *dma_alloc_noncoherent(struct device *dev, size_t size,

		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)

{

	const struct dma_map_ops *ops = get_dma_ops(dev);

	void *vaddr;



	if (!ops || !ops->alloc_noncoherent) {

		struct page *page;



		page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
@@ -520,12 +524,29 @@ void *dma_alloc_noncoherent(struct device *dev, size_t size, 
			return NULL;

		return page_address(page);

	}



	size = PAGE_ALIGN(size);

	vaddr = ops->alloc_noncoherent(dev, size, dma_handle, dir, gfp);

	if (vaddr)

		debug_dma_map_page(dev, virt_to_page(vaddr), 0, size, dir,

				   *dma_handle);

	return vaddr;

}

EXPORT_SYMBOL_GPL(dma_alloc_noncoherent);



void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,

		dma_addr_t dma_handle, enum dma_data_direction dir)

{

	const struct dma_map_ops *ops = get_dma_ops(dev);



	if (!ops || !ops->free_noncoherent) {

		dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir);

		return;

	}



	size = PAGE_ALIGN(size);

	debug_dma_unmap_page(dev, dma_handle, size, dir);

	ops->free_noncoherent(dev, size, vaddr, dma_handle, dir);

}

EXPORT_SYMBOL_GPL(dma_free_noncoherent);