/* Consolidate skb with a frag_list into a brand new one with local pages on
* frags. Returns 0 or -ENOMEM if can't allocate new pages.
*/
static int xenvif_handle_frag_list(struct xenvif *vif, struct sk_buff *skb)
{
unsigned int offset = skb_headlen(skb);
skb_frag_t frags[MAX_SKB_FRAGS];
int i;
struct ubuf_info *uarg;
struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
vif->tx_zerocopy_sent += 2;
vif->tx_frag_overflow++;
xenvif_fill_frags(vif, nskb);
/* Subtract frags size, we will correct it later */
skb->truesize -= skb->data_len;
skb->len += nskb->len;
skb->data_len += nskb->len;
/* create a brand new frags array and coalesce there */
for (i = 0; offset < skb->len; i++) {
struct page *page;
unsigned int len;
BUG_ON(i >= MAX_SKB_FRAGS);
page = alloc_page(GFP_ATOMIC|__GFP_COLD);
if (!page) {
int j;
skb->truesize += skb->data_len;
for (j = 0; j < i; j++)
put_page(frags[j].page.p);
return -ENOMEM;
}
if (offset + PAGE_SIZE < skb->len)
len = PAGE_SIZE;
else
len = skb->len - offset;
if (skb_copy_bits(skb, offset, page_address(page), len))
BUG();
offset += len;
frags[i].page.p = page;
frags[i].page_offset = 0;
skb_frag_size_set(&frags[i], len);
}
/* swap out with old one */
memcpy(skb_shinfo(skb)->frags,
frags,
i * sizeof(skb_frag_t));
skb_shinfo(skb)->nr_frags = i;
skb->truesize += i * PAGE_SIZE;
/* remove traces of mapped pages and frag_list */
skb_frag_list_init(skb);
uarg = skb_shinfo(skb)->destructor_arg;
uarg->callback(uarg, true);
skb_shinfo(skb)->destructor_arg = NULL;
skb_shinfo(nskb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
kfree_skb(nskb);
return 0;
}
static int xenvif_tx_submit(struct xenvif *vif)
{
struct gnttab_map_grant_ref *gop_map = vif->tx_map_ops;
struct gnttab_copy *gop_copy = vif->tx_copy_ops;
struct sk_buff *skb;
int work_done = 0;
while ((skb = __skb_dequeue(&vif->tx_queue)) != NULL) {
struct xen_netif_tx_request *txp;
u16 pending_idx;
unsigned data_len;
pending_idx = XENVIF_TX_CB(skb)->pending_idx;
txp = &vif->pending_tx_info[pending_idx].req;
/* Check the remap error code. */
if (unlikely(xenvif_tx_check_gop(vif, skb, &gop_map, &gop_copy))) {
skb_shinfo(skb)->nr_frags = 0;
kfree_skb(skb);
continue;
}
data_len = skb->len;
callback_param(vif, pending_idx).ctx = NULL;
if (data_len < txp->size) {
/* Append the packet payload as a fragment. */
txp->offset += data_len;
txp->size -= data_len;
} else {
/* Schedule a response immediately. */
xenvif_idx_release(vif, pending_idx,
XEN_NETIF_RSP_OKAY);
}
if (txp->flags & XEN_NETTXF_csum_blank)
skb->ip_summed = CHECKSUM_PARTIAL;
else if (txp->flags & XEN_NETTXF_data_validated)
skb->ip_summed = CHECKSUM_UNNECESSARY;
xenvif_fill_frags(vif, skb);
if (unlikely(skb_has_frag_list(skb))) {
if (xenvif_handle_frag_list(vif, skb)) {
if (net_ratelimit())
netdev_err(vif->dev,
"Not enough memory to consolidate frag_list!\n");
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
kfree_skb(skb);
continue;
}
}
if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) {
int target = min_t(int, skb->len, PKT_PROT_LEN);
__pskb_pull_tail(skb, target - skb_headlen(skb));
}
skb->dev = vif->dev;
skb->protocol = eth_type_trans(skb, skb->dev);
skb_reset_network_header(skb);
if (checksum_setup(vif, skb)) {
netdev_dbg(vif->dev,
"Can't setup checksum in net_tx_action\n");
/* We have to set this flag to trigger the callback */
if (skb_shinfo(skb)->destructor_arg)
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
kfree_skb(skb);
continue;
}
skb_probe_transport_header(skb, 0);
/* If the packet is GSO then we will have just set up the
* transport header offset in checksum_setup so it's now
* straightforward to calculate gso_segs.
*/
if (skb_is_gso(skb)) {
int mss = skb_shinfo(skb)->gso_size;
int hdrlen = skb_transport_header(skb) -
skb_mac_header(skb) +
tcp_hdrlen(skb);
skb_shinfo(skb)->gso_segs =
DIV_ROUND_UP(skb->len - hdrlen, mss);
}
vif->dev->stats.rx_bytes += skb->len;
vif->dev->stats.rx_packets++;
work_done++;
/* Set this flag right before netif_receive_skb, otherwise
* someone might think this packet already left netback, and
* do a skb_copy_ubufs while we are still in control of the
* skb. E.g. the __pskb_pull_tail earlier can do such thing.
*/
if (skb_shinfo(skb)->destructor_arg) {
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
vif->tx_zerocopy_sent++;
}
netif_receive_skb(skb);
}
static int xenvif_tx_submit(struct xenvif *vif)
{
struct gnttab_copy *gop = vif->tx_copy_ops;
struct sk_buff *skb;
int work_done = 0;
while ((skb = __skb_dequeue(&vif->tx_queue)) != NULL) {
struct xen_netif_tx_request *txp;
u16 pending_idx;
unsigned data_len;
pending_idx = *((u16 *)skb->data);
txp = &vif->pending_tx_info[pending_idx].req;
/* Check the remap error code. */
if (unlikely(xenvif_tx_check_gop(vif, skb, &gop))) {
netdev_dbg(vif->dev, "netback grant failed.\n");
skb_shinfo(skb)->nr_frags = 0;
kfree_skb(skb);
continue;
}
data_len = skb->len;
memcpy(skb->data,
(void *)(idx_to_kaddr(vif, pending_idx)|txp->offset),
data_len);
if (data_len < txp->size) {
/* Append the packet payload as a fragment. */
txp->offset += data_len;
txp->size -= data_len;
} else {
/* Schedule a response immediately. */
xenvif_idx_release(vif, pending_idx,
XEN_NETIF_RSP_OKAY);
}
if (txp->flags & XEN_NETTXF_csum_blank)
skb->ip_summed = CHECKSUM_PARTIAL;
else if (txp->flags & XEN_NETTXF_data_validated)
skb->ip_summed = CHECKSUM_UNNECESSARY;
xenvif_fill_frags(vif, skb);
if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) {
int target = min_t(int, skb->len, PKT_PROT_LEN);
__pskb_pull_tail(skb, target - skb_headlen(skb));
}
skb->dev = vif->dev;
skb->protocol = eth_type_trans(skb, skb->dev);
skb_reset_network_header(skb);
if (checksum_setup(vif, skb)) {
netdev_dbg(vif->dev,
"Can't setup checksum in net_tx_action\n");
kfree_skb(skb);
continue;
}
skb_probe_transport_header(skb, 0);
/* If the packet is GSO then we will have just set up the
* transport header offset in checksum_setup so it's now
* straightforward to calculate gso_segs.
*/
if (skb_is_gso(skb)) {
int mss = skb_shinfo(skb)->gso_size;
int hdrlen = skb_transport_header(skb) -
skb_mac_header(skb) +
tcp_hdrlen(skb);
skb_shinfo(skb)->gso_segs =
DIV_ROUND_UP(skb->len - hdrlen, mss);
}
vif->dev->stats.rx_bytes += skb->len;
vif->dev->stats.rx_packets++;
work_done++;
netif_receive_skb(skb);
}
