[linux-2.6-block.git] / lib / dma-noop.c

/*
 *	lib/dma-noop.c
 *
 * Simple DMA noop-ops that map 1:1 with memory
 */
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>

static void *dma_noop_alloc(struct device *dev, size_t size,
			    dma_addr_t *dma_handle, gfp_t gfp,
			    struct dma_attrs *attrs)
{
	void *ret;

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

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

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

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

	for_each_sg(sgl, sg, nents, i) {
		void *va;

		BUG_ON(!sg_page(sg));
		va = sg_virt(sg);
		sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va);
		sg_dma_len(sg) = sg->length;
	}

	return nents;
}

static int dma_noop_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
	return 0;
}

static int dma_noop_supported(struct device *dev, u64 mask)
{
	return 1;
}

struct dma_map_ops dma_noop_ops = {
	.alloc			= dma_noop_alloc,
	.free			= dma_noop_free,
	.map_page		= dma_noop_map_page,
	.map_sg			= dma_noop_map_sg,
	.mapping_error		= dma_noop_mapping_error,
	.dma_supported		= dma_noop_supported,
};

EXPORT_SYMBOL(dma_noop_ops);
Commit	Line	Data
a8463d4b CB	1	/*
	2	* lib/dma-noop.c
	3	*
	4	* Simple DMA noop-ops that map 1:1 with 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_noop_alloc(struct device dev, size_t size,
	12	dma_addr_t *dma_handle, gfp_t gfp,
	13	struct dma_attrs *attrs)
	14	{
	15	void *ret;
	16
	17	ret = (void *)__get_free_pages(gfp, get_order(size));
	18	if (ret)
	19	*dma_handle = virt_to_phys(ret);
	20	return ret;
	21	}
	22
	23	static void dma_noop_free(struct device *dev, size_t size,
	24	void *cpu_addr, dma_addr_t dma_addr,
	25	struct dma_attrs *attrs)
	26	{
	27	free_pages((unsigned long)cpu_addr, get_order(size));
	28	}
	29
	30	static dma_addr_t dma_noop_map_page(struct device dev, struct page page,
	31	unsigned long offset, size_t size,
	32	enum dma_data_direction dir,
	33	struct dma_attrs *attrs)
	34	{
	35	return page_to_phys(page) + offset;
	36	}
	37
	38	static int dma_noop_map_sg(struct device dev, struct scatterlist sgl, int nents,
	39	enum dma_data_direction dir, struct dma_attrs *attrs)
	40	{
	41	int i;
	42	struct scatterlist *sg;
	43
	44	for_each_sg(sgl, sg, nents, i) {
	45	void *va;
	46
	47	BUG_ON(!sg_page(sg));
	48	va = sg_virt(sg);
	49	sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va);
	50	sg_dma_len(sg) = sg->length;
	51	}
	52
	53	return nents;
	54	}
	55
	56	static int dma_noop_mapping_error(struct device *dev, dma_addr_t dma_addr)
	57	{
	58	return 0;
	59	}
	60
	61	static int dma_noop_supported(struct device *dev, u64 mask)
	62	{
	63	return 1;
	64	}
65
66	struct dma_map_ops dma_noop_ops = {
67	.alloc = dma_noop_alloc,
68	.free = dma_noop_free,
69	.map_page = dma_noop_map_page,
70	.map_sg = dma_noop_map_sg,
71	.mapping_error = dma_noop_mapping_error,
72	.dma_supported = dma_noop_supported,
73	};
74
75	EXPORT_SYMBOL(dma_noop_ops);