67 lines
1.4 KiB
C
67 lines
1.4 KiB
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_maps[0] = 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 + 1] = map;
|
|
}
|
|
sp->num_dma_maps = i + 1;
|
|
|
|
return 0;
|
|
|
|
unwind:
|
|
while (i-- >= 0) {
|
|
skb_frag_t *fp = &sp->frags[i];
|
|
|
|
dma_unmap_page(dev, sp->dma_maps[i + 1],
|
|
fp->size, dir);
|
|
}
|
|
dma_unmap_single(dev, sp->dma_maps[0],
|
|
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_maps[0],
|
|
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 + 1],
|
|
fp->size, dir);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(skb_dma_unmap);
|