[linux.git] / kernel / dma / virt.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
551199ac	2	/*
551199ac BVA	3	* DMA operations that map to virtual addresses without flushing memory.
	4	*/
	5	#include <linux/export.h>
	6	#include <linux/mm.h>
	7	#include <linux/dma-mapping.h>
	8	#include <linux/scatterlist.h>
	9
	10	static void dma_virt_alloc(struct device dev, size_t size,
	11	dma_addr_t *dma_handle, gfp_t gfp,
	12	unsigned long attrs)
	13	{
	14	void *ret;
	15
	16	ret = (void *)__get_free_pages(gfp, get_order(size));
	17	if (ret)
	18	*dma_handle = (uintptr_t)ret;
	19	return ret;
	20	}
	21
	22	static void dma_virt_free(struct device *dev, size_t size,
	23	void *cpu_addr, dma_addr_t dma_addr,
	24	unsigned long attrs)
	25	{
	26	free_pages((unsigned long)cpu_addr, get_order(size));
	27	}
	28
	29	static dma_addr_t dma_virt_map_page(struct device dev, struct page page,
	30	unsigned long offset, size_t size,
	31	enum dma_data_direction dir,
	32	unsigned long attrs)
	33	{
	34	return (uintptr_t)(page_address(page) + offset);
	35	}
	36
	37	static int dma_virt_map_sg(struct device dev, struct scatterlist sgl,
	38	int nents, enum dma_data_direction dir,
	39	unsigned long attrs)
	40	{
	41	int i;
	42	struct scatterlist *sg;
	43
	44	for_each_sg(sgl, sg, nents, i) {
	45	BUG_ON(!sg_page(sg));
	46	sg_dma_address(sg) = (uintptr_t)sg_virt(sg);
	47	sg_dma_len(sg) = sg->length;
	48	}
	49
	50	return nents;
	51	}
	52
551199ac BVA	53	const struct dma_map_ops dma_virt_ops = {
	54	.alloc = dma_virt_alloc,
	55	.free = dma_virt_free,
	56	.map_page = dma_virt_map_page,
	57	.map_sg = dma_virt_map_sg,
551199ac BVA	58	};
551199ac BVA	59	EXPORT_SYMBOL(dma_virt_ops);