[linux-block.git] / net / core / skb_dma_map.c

/* skb_dma_map.c: DMA mapping helpers for socket buffers.
 *
 * Copyright (C) David S. Miller <davem@davemloft.net>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/skbuff.h>

int skb_dma_map(struct device *dev, struct sk_buff *skb,
		enum dma_data_direction dir)
{
	struct skb_shared_info *sp = skb_shinfo(skb);
	dma_addr_t map;
	int i;

	map = dma_map_single(dev, skb->data,
			     skb_headlen(skb), dir);
	if (dma_mapping_error(dev, map))
		goto out_err;

	sp->dma_head = map;
	for (i = 0; i < sp->nr_frags; i++) {
		skb_frag_t *fp = &sp->frags[i];

		map = dma_map_page(dev, fp->page, fp->page_offset,
				   fp->size, dir);
		if (dma_mapping_error(dev, map))
			goto unwind;
		sp->dma_maps[i] = map;
	}

	return 0;

unwind:
	while (--i >= 0) {
		skb_frag_t *fp = &sp->frags[i];

		dma_unmap_page(dev, sp->dma_maps[i],
			       fp->size, dir);
	}
	dma_unmap_single(dev, sp->dma_head,
			 skb_headlen(skb), dir);
out_err:
	return -ENOMEM;
}
EXPORT_SYMBOL(skb_dma_map);

void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
		   enum dma_data_direction dir)
{
	struct skb_shared_info *sp = skb_shinfo(skb);
	int i;

	dma_unmap_single(dev, sp->dma_head,
			 skb_headlen(skb), dir);
	for (i = 0; i < sp->nr_frags; i++) {
		skb_frag_t *fp = &sp->frags[i];

		dma_unmap_page(dev, sp->dma_maps[i],
			       fp->size, dir);
	}
}
EXPORT_SYMBOL(skb_dma_unmap);
Commit	Line	Data
a40c24a1 DM	1	/* skb_dma_map.c: DMA mapping helpers for socket buffers.
	2	*
	3	* Copyright (C) David S. Miller <davem@davemloft.net>
	4	*/
	5
	6	#include <linux/kernel.h>
	7	#include <linux/module.h>
	8	#include <linux/dma-mapping.h>
	9	#include <linux/skbuff.h>
	10
	11	int skb_dma_map(struct device dev, struct sk_buff skb,
	12	enum dma_data_direction dir)
	13	{
	14	struct skb_shared_info *sp = skb_shinfo(skb);
	15	dma_addr_t map;
	16	int i;
	17
	18	map = dma_map_single(dev, skb->data,
	19	skb_headlen(skb), dir);
	20	if (dma_mapping_error(dev, map))
	21	goto out_err;
	22
042a53a9	23	sp->dma_head = map;
a40c24a1 DM	24	for (i = 0; i < sp->nr_frags; i++) {
	25	skb_frag_t *fp = &sp->frags[i];
	26
	27	map = dma_map_page(dev, fp->page, fp->page_offset,
	28	fp->size, dir);
	29	if (dma_mapping_error(dev, map))
	30	goto unwind;
042a53a9	31	sp->dma_maps[i] = map;
a40c24a1	32	}
a40c24a1 DM	33
	34	return 0;
	35
	36	unwind:
ab396eb0	37	while (--i >= 0) {
a40c24a1 DM	38	skb_frag_t *fp = &sp->frags[i];
a40c24a1 DM	39
042a53a9	40	dma_unmap_page(dev, sp->dma_maps[i],
a40c24a1 DM	41	fp->size, dir);
a40c24a1 DM	42	}
042a53a9	43	dma_unmap_single(dev, sp->dma_head,
a40c24a1 DM	44	skb_headlen(skb), dir);
	45	out_err:
	46	return -ENOMEM;
	47	}
	48	EXPORT_SYMBOL(skb_dma_map);
	49
	50	void skb_dma_unmap(struct device dev, struct sk_buff skb,
	51	enum dma_data_direction dir)
	52	{
	53	struct skb_shared_info *sp = skb_shinfo(skb);
	54	int i;
	55
042a53a9	56	dma_unmap_single(dev, sp->dma_head,
a40c24a1 DM	57	skb_headlen(skb), dir);
	58	for (i = 0; i < sp->nr_frags; i++) {
	59	skb_frag_t *fp = &sp->frags[i];
	60
042a53a9	61	dma_unmap_page(dev, sp->dma_maps[i],
a40c24a1 DM	62	fp->size, dir);
	63	}
	64	}
	65	EXPORT_SYMBOL(skb_dma_unmap);