static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb)
{
struct skb_shared_info *shinfo = skb_shinfo(skb);
int nr_frags = shinfo->nr_frags;
int i;
for (i = 0; i < nr_frags; i++) {
skb_frag_t *frag = shinfo->frags + i;
struct xen_netif_tx_request *txp;
struct page *page;
u16 pending_idx;
pending_idx = frag_get_pending_idx(frag);
txp = &vif->pending_tx_info[pending_idx].req;
page = virt_to_page(idx_to_kaddr(vif, pending_idx));
__skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
skb->len += txp->size;
skb->data_len += txp->size;
skb->truesize += txp->size;
/* Take an extra reference to offset xenvif_idx_release */
get_page(vif->mmap_pages[pending_idx]);
xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY);
}
}
static inline void xenvif_tx_create_map_op(struct xenvif *vif,
u16 pending_idx,
struct xen_netif_tx_request *txp,
struct gnttab_map_grant_ref *mop)
{
vif->pages_to_map[mop-vif->tx_map_ops] = vif->mmap_pages[pending_idx];
gnttab_set_map_op(mop, idx_to_kaddr(vif, pending_idx),
GNTMAP_host_map | GNTMAP_readonly,
txp->gref, vif->domid);
memcpy(&vif->pending_tx_info[pending_idx].req, txp,
sizeof(*txp));
}
static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb)
{
struct skb_shared_info *shinfo = skb_shinfo(skb);
int nr_frags = shinfo->nr_frags;
int i;
u16 prev_pending_idx = INVALID_PENDING_IDX;
for (i = 0; i < nr_frags; i++) {
skb_frag_t *frag = shinfo->frags + i;
struct xen_netif_tx_request *txp;
struct page *page;
u16 pending_idx;
pending_idx = frag_get_pending_idx(frag);
/* If this is not the first frag, chain it to the previous*/
if (prev_pending_idx == INVALID_PENDING_IDX)
skb_shinfo(skb)->destructor_arg =
&callback_param(vif, pending_idx);
else
callback_param(vif, prev_pending_idx).ctx =
&callback_param(vif, pending_idx);
callback_param(vif, pending_idx).ctx = NULL;
prev_pending_idx = pending_idx;
txp = &vif->pending_tx_info[pending_idx].req;
page = virt_to_page(idx_to_kaddr(vif, pending_idx));
__skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
skb->len += txp->size;
skb->data_len += txp->size;
skb->truesize += txp->size;
/* Take an extra reference to offset network stack's put_page */
get_page(vif->mmap_pages[pending_idx]);
}
/* FIXME: __skb_fill_page_desc set this to true because page->pfmemalloc
* overlaps with "index", and "mapping" is not set. I think mapping
* should be set. If delivered to local stack, it would drop this
* skb in sk_filter unless the socket has the right to use it.
*/
skb->pfmemalloc = false;
}
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);
}