Signed-off-by: Shirley Ma <[email protected]> -------------- diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index bb5eb7b..100b4b9 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -80,29 +80,25 @@ static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) return (struct skb_vnet_hdr *)skb->cb; } -static void give_a_page(struct virtnet_info *vi, struct page *page) +static void give_pages(struct virtnet_info *vi, struct page *page) { - page->private = (unsigned long)vi->pages; - vi->pages = page; -} + struct page *end; -static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb) -{ - unsigned int i; - - for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) - give_a_page(vi, skb_shinfo(skb)->frags[i].page); - skb_shinfo(skb)->nr_frags = 0; - skb->data_len = 0; + /* Find end of list, sew whole thing into vi->pages. */ + for (end = page; end->private; end = (struct page *)end->private); + end->private = (unsigned long)vi->pages; + vi->pages = page; } static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) { struct page *p = vi->pages; - if (p) + if (p) { vi->pages = (struct page *)p->private; - else + /* use private to chain pages for big packets */ + p->private = 0; + } else p = alloc_page(gfp_mask); return p; } @@ -128,6 +124,85 @@ static void skb_xmit_done(struct virtqueue *svq) netif_wake_queue(vi->dev); } +static int skb_set_frag(struct sk_buff *skb, struct page *page, + int offset, int len) +{ + int i = skb_shinfo(skb)->nr_frags; + skb_frag_t *f; + + i = skb_shinfo(skb)->nr_frags; + f = &skb_shinfo(skb)->frags[i]; + f->page = page; + f->page_offset = offset; + + if (len > PAGE_SIZE - f->page_offset) + f->size = PAGE_SIZE - f->page_offset; + else + f->size = len; + + skb_shinfo(skb)->nr_frags++; + skb->data_len += f->size; + skb->len += f->size; + + len -= f->size; + return len; +} + +static struct sk_buff *skb_goodcopy(struct virtnet_info *vi, struct page **page, + unsigned int *len) +{ + struct sk_buff *skb; + struct skb_vnet_hdr *hdr; + int copy, hdr_len, offset; + char *p; + + p = page_address(*page); + + skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN); + if (unlikely(!skb)) + return NULL; + + skb_reserve(skb, NET_IP_ALIGN); + hdr = skb_vnet_hdr(skb); + + if (vi->mergeable_rx_bufs) { + hdr_len = sizeof(hdr->mhdr); + offset = hdr_len; + } else { + /* share one page between virtio_net header and data */ + struct padded_vnet_hdr { + struct virtio_net_hdr hdr; + /* This padding makes our data 16 byte aligned */ + char padding[6]; + }; + hdr_len = sizeof(hdr->hdr); + offset = sizeof(struct padded_vnet_hdr); + } + + memcpy(hdr, p, hdr_len); + + *len -= hdr_len; + p += offset; + + copy = *len; + if (copy > skb_tailroom(skb)) + copy = skb_tailroom(skb); + memcpy(skb_put(skb, copy), p, copy); + + *len -= copy; + offset += copy; + + if (*len) { + *len = skb_set_frag(skb, *page, offset, *len); + *page = (struct page *)(*page)->private; + } else { + give_pages(vi, *page); + *page = NULL; + } + + return skb; +} + static void receive_skb(struct net_device *dev, struct sk_buff *skb, unsigned len) { @@ -162,7 +237,7 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb, len -= copy; if (!len) { - give_a_page(vi, skb_shinfo(skb)->frags[0].page); + give_pages(vi, skb_shinfo(skb)->frags[0].page); skb_shinfo(skb)->nr_frags--; } else { skb_shinfo(skb)->frags[0].page_offset +=
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