[linux.git] / lib / dma-virt.c

/*
 *	lib/dma-virt.c
 *
 * DMA operations that map to virtual addresses without flushing memory.
 */
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>

static void *dma_virt_alloc(struct device *dev, size_t size,
			    dma_addr_t *dma_handle, gfp_t gfp,
			    unsigned long attrs)
{
	void *ret;

	ret = (void *)__get_free_pages(gfp, get_order(size));
	if (ret)
		*dma_handle = (uintptr_t)ret;
	return ret;
}

static void dma_virt_free(struct device *dev, size_t size,
			  void *cpu_addr, dma_addr_t dma_addr,
			  unsigned long attrs)
{
	free_pages((unsigned long)cpu_addr, get_order(size));
}

static dma_addr_t dma_virt_map_page(struct device *dev, struct page *page,
				    unsigned long offset, size_t size,
				    enum dma_data_direction dir,
				    unsigned long attrs)
{
	return (uintptr_t)(page_address(page) + offset);
}

static int dma_virt_map_sg(struct device *dev, struct scatterlist *sgl,
			   int nents, enum dma_data_direction dir,
			   unsigned long attrs)
{
	int i;
	struct scatterlist *sg;

	for_each_sg(sgl, sg, nents, i) {
		BUG_ON(!sg_page(sg));
		sg_dma_address(sg) = (uintptr_t)sg_virt(sg);
		sg_dma_len(sg) = sg->length;
	}

	return nents;
}

const struct dma_map_ops dma_virt_ops = {
	.alloc			= dma_virt_alloc,
	.free			= dma_virt_free,
	.map_page		= dma_virt_map_page,
	.map_sg			= dma_virt_map_sg,
};
EXPORT_SYMBOL(dma_virt_ops);
Commit	Line	Data
551199ac BVA	1	/*
	2	* lib/dma-virt.c
	3	*
	4	* DMA operations that map to virtual addresses without flushing memory.
	5	*/
	6	#include <linux/export.h>
	7	#include <linux/mm.h>
	8	#include <linux/dma-mapping.h>
	9	#include <linux/scatterlist.h>
	10
	11	static void dma_virt_alloc(struct device dev, size_t size,
	12	dma_addr_t *dma_handle, gfp_t gfp,
	13	unsigned long attrs)
	14	{
	15	void *ret;
	16
	17	ret = (void *)__get_free_pages(gfp, get_order(size));
	18	if (ret)
	19	*dma_handle = (uintptr_t)ret;
	20	return ret;
	21	}
	22
	23	static void dma_virt_free(struct device *dev, size_t size,
	24	void *cpu_addr, dma_addr_t dma_addr,
	25	unsigned long attrs)
	26	{
	27	free_pages((unsigned long)cpu_addr, get_order(size));
	28	}
	29
	30	static dma_addr_t dma_virt_map_page(struct device dev, struct page page,
	31	unsigned long offset, size_t size,
	32	enum dma_data_direction dir,
	33	unsigned long attrs)
	34	{
	35	return (uintptr_t)(page_address(page) + offset);
	36	}
	37
	38	static int dma_virt_map_sg(struct device dev, struct scatterlist sgl,
	39	int nents, enum dma_data_direction dir,
	40	unsigned long attrs)
	41	{
	42	int i;
	43	struct scatterlist *sg;
	44
	45	for_each_sg(sgl, sg, nents, i) {
	46	BUG_ON(!sg_page(sg));
	47	sg_dma_address(sg) = (uintptr_t)sg_virt(sg);
	48	sg_dma_len(sg) = sg->length;
	49	}
	50
	51	return nents;
	52	}
	53
551199ac BVA	54	const struct dma_map_ops dma_virt_ops = {
	55	.alloc = dma_virt_alloc,
	56	.free = dma_virt_free,
	57	.map_page = dma_virt_map_page,
	58	.map_sg = dma_virt_map_sg,
551199ac BVA	59	};
551199ac BVA	60	EXPORT_SYMBOL(dma_virt_ops);