diff options
| -rw-r--r-- | include/linux/skbuff.h | 8 | ||||
| -rw-r--r-- | net/core/Makefile | 1 | ||||
| -rw-r--r-- | net/core/skb_dma_map.c | 66 |
3 files changed, 75 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 4b2be23..aa80ad9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -359,6 +359,14 @@ struct sk_buff { #include <asm/system.h> +#ifdef CONFIG_HAS_DMA +#include <linux/dma-mapping.h> +extern int skb_dma_map(struct device *dev, struct sk_buff *skb, + enum dma_data_direction dir); +extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb, + enum dma_data_direction dir); +#endif + extern void kfree_skb(struct sk_buff *skb); extern void __kfree_skb(struct sk_buff *skb); extern struct sk_buff *__alloc_skb(unsigned int size, diff --git a/net/core/Makefile b/net/core/Makefile index b1332f6..26a37cb 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -6,6 +6,7 @@ obj-y := sock.o request_sock.o skbuff.o iovec.o datagram.o stream.o scm.o \ gen_stats.o gen_estimator.o net_namespace.o obj-$(CONFIG_SYSCTL) += sysctl_net_core.o +obj-$(CONFIG_HAS_DMA) += skb_dma_map.o obj-y += dev.o ethtool.o dev_mcast.o dst.o netevent.o \ neighbour.o rtnetlink.o utils.o link_watch.o filter.o diff --git a/net/core/skb_dma_map.c b/net/core/skb_dma_map.c new file mode 100644 index 0000000..1f49afc --- /dev/null +++ b/net/core/skb_dma_map.c @@ -0,0 +1,66 @@ +/* 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); |