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path: root/drivers/net/xen-netback/netback.c
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Diffstat (limited to 'drivers/net/xen-netback/netback.c')
-rw-r--r--drivers/net/xen-netback/netback.c506
1 files changed, 96 insertions, 410 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 78425554a537..6b62c3eb8e18 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -39,7 +39,6 @@
#include <linux/udp.h>
#include <net/tcp.h>
-#include <net/ip6_checksum.h>
#include <xen/xen.h>
#include <xen/events.h>
@@ -138,36 +137,26 @@ static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif)
vif->pending_prod + vif->pending_cons;
}
-static int max_required_rx_slots(struct xenvif *vif)
+bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed)
{
- int max = DIV_ROUND_UP(vif->dev->mtu, PAGE_SIZE);
+ RING_IDX prod, cons;
- /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */
- if (vif->can_sg || vif->gso_mask || vif->gso_prefix_mask)
- max += MAX_SKB_FRAGS + 1; /* extra_info + frags */
-
- return max;
-}
+ do {
+ prod = vif->rx.sring->req_prod;
+ cons = vif->rx.req_cons;
-int xenvif_rx_ring_full(struct xenvif *vif)
-{
- RING_IDX peek = vif->rx_req_cons_peek;
- RING_IDX needed = max_required_rx_slots(vif);
+ if (prod - cons >= needed)
+ return true;
- return ((vif->rx.sring->req_prod - peek) < needed) ||
- ((vif->rx.rsp_prod_pvt + XEN_NETIF_RX_RING_SIZE - peek) < needed);
-}
+ vif->rx.sring->req_event = prod + 1;
-int xenvif_must_stop_queue(struct xenvif *vif)
-{
- if (!xenvif_rx_ring_full(vif))
- return 0;
-
- vif->rx.sring->req_event = vif->rx_req_cons_peek +
- max_required_rx_slots(vif);
- mb(); /* request notification /then/ check the queue */
+ /* Make sure event is visible before we check prod
+ * again.
+ */
+ mb();
+ } while (vif->rx.sring->req_prod != prod);
- return xenvif_rx_ring_full(vif);
+ return false;
}
/*
@@ -210,93 +199,6 @@ static bool start_new_rx_buffer(int offset, unsigned long size, int head)
return false;
}
-struct xenvif_count_slot_state {
- unsigned long copy_off;
- bool head;
-};
-
-unsigned int xenvif_count_frag_slots(struct xenvif *vif,
- unsigned long offset, unsigned long size,
- struct xenvif_count_slot_state *state)
-{
- unsigned count = 0;
-
- offset &= ~PAGE_MASK;
-
- while (size > 0) {
- unsigned long bytes;
-
- bytes = PAGE_SIZE - offset;
-
- if (bytes > size)
- bytes = size;
-
- if (start_new_rx_buffer(state->copy_off, bytes, state->head)) {
- count++;
- state->copy_off = 0;
- }
-
- if (state->copy_off + bytes > MAX_BUFFER_OFFSET)
- bytes = MAX_BUFFER_OFFSET - state->copy_off;
-
- state->copy_off += bytes;
-
- offset += bytes;
- size -= bytes;
-
- if (offset == PAGE_SIZE)
- offset = 0;
-
- state->head = false;
- }
-
- return count;
-}
-
-/*
- * Figure out how many ring slots we're going to need to send @skb to
- * the guest. This function is essentially a dry run of
- * xenvif_gop_frag_copy.
- */
-unsigned int xenvif_count_skb_slots(struct xenvif *vif, struct sk_buff *skb)
-{
- struct xenvif_count_slot_state state;
- unsigned int count;
- unsigned char *data;
- unsigned i;
-
- state.head = true;
- state.copy_off = 0;
-
- /* Slot for the first (partial) page of data. */
- count = 1;
-
- /* Need a slot for the GSO prefix for GSO extra data? */
- if (skb_shinfo(skb)->gso_size)
- count++;
-
- data = skb->data;
- while (data < skb_tail_pointer(skb)) {
- unsigned long offset = offset_in_page(data);
- unsigned long size = PAGE_SIZE - offset;
-
- if (data + size > skb_tail_pointer(skb))
- size = skb_tail_pointer(skb) - data;
-
- count += xenvif_count_frag_slots(vif, offset, size, &state);
-
- data += size;
- }
-
- for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
- unsigned long size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
- unsigned long offset = skb_shinfo(skb)->frags[i].page_offset;
-
- count += xenvif_count_frag_slots(vif, offset, size, &state);
- }
- return count;
-}
-
struct netrx_pending_operations {
unsigned copy_prod, copy_cons;
unsigned meta_prod, meta_cons;
@@ -557,12 +459,12 @@ struct skb_cb_overlay {
int meta_slots_used;
};
-static void xenvif_kick_thread(struct xenvif *vif)
+void xenvif_kick_thread(struct xenvif *vif)
{
wake_up(&vif->wq);
}
-void xenvif_rx_action(struct xenvif *vif)
+static void xenvif_rx_action(struct xenvif *vif)
{
s8 status;
u16 flags;
@@ -571,11 +473,10 @@ void xenvif_rx_action(struct xenvif *vif)
struct sk_buff *skb;
LIST_HEAD(notify);
int ret;
- int nr_frags;
- int count;
unsigned long offset;
struct skb_cb_overlay *sco;
- int need_to_notify = 0;
+ bool need_to_notify = false;
+ bool ring_full = false;
struct netrx_pending_operations npo = {
.copy = vif->grant_copy_op,
@@ -584,29 +485,47 @@ void xenvif_rx_action(struct xenvif *vif)
skb_queue_head_init(&rxq);
- count = 0;
-
while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) {
- vif = netdev_priv(skb->dev);
- nr_frags = skb_shinfo(skb)->nr_frags;
+ int max_slots_needed;
+ int i;
+
+ /* We need a cheap worse case estimate for the number of
+ * slots we'll use.
+ */
+
+ max_slots_needed = DIV_ROUND_UP(offset_in_page(skb->data) +
+ skb_headlen(skb),
+ PAGE_SIZE);
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ unsigned int size;
+ size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
+ max_slots_needed += DIV_ROUND_UP(size, PAGE_SIZE);
+ }
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 ||
+ skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+ max_slots_needed++;
+
+ /* If the skb may not fit then bail out now */
+ if (!xenvif_rx_ring_slots_available(vif, max_slots_needed)) {
+ skb_queue_head(&vif->rx_queue, skb);
+ need_to_notify = true;
+ ring_full = true;
+ break;
+ }
sco = (struct skb_cb_overlay *)skb->cb;
sco->meta_slots_used = xenvif_gop_skb(skb, &npo);
-
- count += nr_frags + 1;
+ BUG_ON(sco->meta_slots_used > max_slots_needed);
__skb_queue_tail(&rxq, skb);
-
- /* Filled the batch queue? */
- /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */
- if (count + MAX_SKB_FRAGS >= XEN_NETIF_RX_RING_SIZE)
- break;
}
BUG_ON(npo.meta_prod > ARRAY_SIZE(vif->meta));
+ vif->rx_queue_stopped = !npo.copy_prod && ring_full;
+
if (!npo.copy_prod)
- return;
+ goto done;
BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS);
gnttab_batch_copy(vif->grant_copy_op, npo.copy_prod);
@@ -614,8 +533,6 @@ void xenvif_rx_action(struct xenvif *vif)
while ((skb = __skb_dequeue(&rxq)) != NULL) {
sco = (struct skb_cb_overlay *)skb->cb;
- vif = netdev_priv(skb->dev);
-
if ((1 << vif->meta[npo.meta_cons].gso_type) &
vif->gso_prefix_mask) {
resp = RING_GET_RESPONSE(&vif->rx,
@@ -678,28 +595,15 @@ void xenvif_rx_action(struct xenvif *vif)
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret);
- if (ret)
- need_to_notify = 1;
-
- xenvif_notify_tx_completion(vif);
+ need_to_notify |= !!ret;
npo.meta_cons += sco->meta_slots_used;
dev_kfree_skb(skb);
}
+done:
if (need_to_notify)
notify_remote_via_irq(vif->rx_irq);
-
- /* More work to do? */
- if (!skb_queue_empty(&vif->rx_queue))
- xenvif_kick_thread(vif);
-}
-
-void xenvif_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb)
-{
- skb_queue_tail(&vif->rx_queue, skb);
-
- xenvif_kick_thread(vif);
}
void xenvif_check_rx_xenvif(struct xenvif *vif)
@@ -1141,265 +1045,14 @@ static int xenvif_set_skb_gso(struct xenvif *vif,
}
skb_shinfo(skb)->gso_size = gso->u.gso.size;
-
- /* Header must be checked, and gso_segs computed. */
- skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
- skb_shinfo(skb)->gso_segs = 0;
-
- return 0;
-}
-
-static inline int maybe_pull_tail(struct sk_buff *skb, unsigned int len,
- unsigned int max)
-{
- if (skb_headlen(skb) >= len)
- return 0;
-
- /* If we need to pullup then pullup to the max, so we
- * won't need to do it again.
- */
- if (max > skb->len)
- max = skb->len;
-
- if (__pskb_pull_tail(skb, max - skb_headlen(skb)) == NULL)
- return -ENOMEM;
-
- if (skb_headlen(skb) < len)
- return -EPROTO;
+ /* gso_segs will be calculated later */
return 0;
}
-/* This value should be large enough to cover a tagged ethernet header plus
- * maximally sized IP and TCP or UDP headers.
- */
-#define MAX_IP_HDR_LEN 128
-
-static int checksum_setup_ip(struct xenvif *vif, struct sk_buff *skb,
- int recalculate_partial_csum)
-{
- unsigned int off;
- bool fragment;
- int err;
-
- fragment = false;
-
- err = maybe_pull_tail(skb,
- sizeof(struct iphdr),
- MAX_IP_HDR_LEN);
- if (err < 0)
- goto out;
-
- if (ip_hdr(skb)->frag_off & htons(IP_OFFSET | IP_MF))
- fragment = true;
-
- off = ip_hdrlen(skb);
-
- err = -EPROTO;
-
- if (fragment)
- goto out;
-
- switch (ip_hdr(skb)->protocol) {
- case IPPROTO_TCP:
- err = maybe_pull_tail(skb,
- off + sizeof(struct tcphdr),
- MAX_IP_HDR_LEN);
- if (err < 0)
- goto out;
-
- if (!skb_partial_csum_set(skb, off,
- offsetof(struct tcphdr, check))) {
- err = -EPROTO;
- goto out;
- }
-
- if (recalculate_partial_csum)
- tcp_hdr(skb)->check =
- ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
- ip_hdr(skb)->daddr,
- skb->len - off,
- IPPROTO_TCP, 0);
- break;
- case IPPROTO_UDP:
- err = maybe_pull_tail(skb,
- off + sizeof(struct udphdr),
- MAX_IP_HDR_LEN);
- if (err < 0)
- goto out;
-
- if (!skb_partial_csum_set(skb, off,
- offsetof(struct udphdr, check))) {
- err = -EPROTO;
- goto out;
- }
-
- if (recalculate_partial_csum)
- udp_hdr(skb)->check =
- ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
- ip_hdr(skb)->daddr,
- skb->len - off,
- IPPROTO_UDP, 0);
- break;
- default:
- goto out;
- }
-
- err = 0;
-
-out:
- return err;
-}
-
-/* This value should be large enough to cover a tagged ethernet header plus
- * an IPv6 header, all options, and a maximal TCP or UDP header.
- */
-#define MAX_IPV6_HDR_LEN 256
-
-#define OPT_HDR(type, skb, off) \
- (type *)(skb_network_header(skb) + (off))
-
-static int checksum_setup_ipv6(struct xenvif *vif, struct sk_buff *skb,
- int recalculate_partial_csum)
-{
- int err;
- u8 nexthdr;
- unsigned int off;
- unsigned int len;
- bool fragment;
- bool done;
-
- fragment = false;
- done = false;
-
- off = sizeof(struct ipv6hdr);
-
- err = maybe_pull_tail(skb, off, MAX_IPV6_HDR_LEN);
- if (err < 0)
- goto out;
-
- nexthdr = ipv6_hdr(skb)->nexthdr;
-
- len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len);
- while (off <= len && !done) {
- switch (nexthdr) {
- case IPPROTO_DSTOPTS:
- case IPPROTO_HOPOPTS:
- case IPPROTO_ROUTING: {
- struct ipv6_opt_hdr *hp;
-
- err = maybe_pull_tail(skb,
- off +
- sizeof(struct ipv6_opt_hdr),
- MAX_IPV6_HDR_LEN);
- if (err < 0)
- goto out;
-
- hp = OPT_HDR(struct ipv6_opt_hdr, skb, off);
- nexthdr = hp->nexthdr;
- off += ipv6_optlen(hp);
- break;
- }
- case IPPROTO_AH: {
- struct ip_auth_hdr *hp;
-
- err = maybe_pull_tail(skb,
- off +
- sizeof(struct ip_auth_hdr),
- MAX_IPV6_HDR_LEN);
- if (err < 0)
- goto out;
-
- hp = OPT_HDR(struct ip_auth_hdr, skb, off);
- nexthdr = hp->nexthdr;
- off += ipv6_authlen(hp);
- break;
- }
- case IPPROTO_FRAGMENT: {
- struct frag_hdr *hp;
-
- err = maybe_pull_tail(skb,
- off +
- sizeof(struct frag_hdr),
- MAX_IPV6_HDR_LEN);
- if (err < 0)
- goto out;
-
- hp = OPT_HDR(struct frag_hdr, skb, off);
-
- if (hp->frag_off & htons(IP6_OFFSET | IP6_MF))
- fragment = true;
-
- nexthdr = hp->nexthdr;
- off += sizeof(struct frag_hdr);
- break;
- }
- default:
- done = true;
- break;
- }
- }
-
- err = -EPROTO;
-
- if (!done || fragment)
- goto out;
-
- switch (nexthdr) {
- case IPPROTO_TCP:
- err = maybe_pull_tail(skb,
- off + sizeof(struct tcphdr),
- MAX_IPV6_HDR_LEN);
- if (err < 0)
- goto out;
-
- if (!skb_partial_csum_set(skb, off,
- offsetof(struct tcphdr, check))) {
- err = -EPROTO;
- goto out;
- }
-
- if (recalculate_partial_csum)
- tcp_hdr(skb)->check =
- ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
- &ipv6_hdr(skb)->daddr,
- skb->len - off,
- IPPROTO_TCP, 0);
- break;
- case IPPROTO_UDP:
- err = maybe_pull_tail(skb,
- off + sizeof(struct udphdr),
- MAX_IPV6_HDR_LEN);
- if (err < 0)
- goto out;
-
- if (!skb_partial_csum_set(skb, off,
- offsetof(struct udphdr, check))) {
- err = -EPROTO;
- goto out;
- }
-
- if (recalculate_partial_csum)
- udp_hdr(skb)->check =
- ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
- &ipv6_hdr(skb)->daddr,
- skb->len - off,
- IPPROTO_UDP, 0);
- break;
- default:
- goto out;
- }
-
- err = 0;
-
-out:
- return err;
-}
-
static int checksum_setup(struct xenvif *vif, struct sk_buff *skb)
{
- int err = -EPROTO;
- int recalculate_partial_csum = 0;
+ bool recalculate_partial_csum = false;
/* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
* peers can fail to set NETRXF_csum_blank when sending a GSO
@@ -1409,19 +1062,14 @@ static int checksum_setup(struct xenvif *vif, struct sk_buff *skb)
if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
vif->rx_gso_checksum_fixup++;
skb->ip_summed = CHECKSUM_PARTIAL;
- recalculate_partial_csum = 1;
+ recalculate_partial_csum = true;
}
/* A non-CHECKSUM_PARTIAL SKB does not require setup. */
if (skb->ip_summed != CHECKSUM_PARTIAL)
return 0;
- if (skb->protocol == htons(ETH_P_IP))
- err = checksum_setup_ip(vif, skb, recalculate_partial_csum);
- else if (skb->protocol == htons(ETH_P_IPV6))
- err = checksum_setup_ipv6(vif, skb, recalculate_partial_csum);
-
- return err;
+ return skb_checksum_setup(skb, recalculate_partial_csum);
}
static bool tx_credit_exceeded(struct xenvif *vif, unsigned size)
@@ -1687,6 +1335,20 @@ static int xenvif_tx_submit(struct xenvif *vif)
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++;
@@ -1811,7 +1473,8 @@ static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
static inline int rx_work_todo(struct xenvif *vif)
{
- return !skb_queue_empty(&vif->rx_queue);
+ return (!skb_queue_empty(&vif->rx_queue) && !vif->rx_queue_stopped) ||
+ vif->rx_event;
}
static inline int tx_work_todo(struct xenvif *vif)
@@ -1861,8 +1524,6 @@ int xenvif_map_frontend_rings(struct xenvif *vif,
rxs = (struct xen_netif_rx_sring *)addr;
BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE);
- vif->rx_req_cons_peek = 0;
-
return 0;
err:
@@ -1870,9 +1531,24 @@ err:
return err;
}
+void xenvif_stop_queue(struct xenvif *vif)
+{
+ if (!vif->can_queue)
+ return;
+
+ netif_stop_queue(vif->dev);
+}
+
+static void xenvif_start_queue(struct xenvif *vif)
+{
+ if (xenvif_schedulable(vif))
+ netif_wake_queue(vif->dev);
+}
+
int xenvif_kthread(void *data)
{
struct xenvif *vif = data;
+ struct sk_buff *skb;
while (!kthread_should_stop()) {
wait_event_interruptible(vif->wq,
@@ -1881,12 +1557,22 @@ int xenvif_kthread(void *data)
if (kthread_should_stop())
break;
- if (rx_work_todo(vif))
+ if (!skb_queue_empty(&vif->rx_queue))
xenvif_rx_action(vif);
+ vif->rx_event = false;
+
+ if (skb_queue_empty(&vif->rx_queue) &&
+ netif_queue_stopped(vif->dev))
+ xenvif_start_queue(vif);
+
cond_resched();
}
+ /* Bin any remaining skbs */
+ while ((skb = skb_dequeue(&vif->rx_queue)) != NULL)
+ dev_kfree_skb(skb);
+
return 0;
}