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path: root/drivers/net/xen-netfront.c
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Diffstat (limited to 'drivers/net/xen-netfront.c')
-rw-r--r--drivers/net/xen-netfront.c135
1 files changed, 86 insertions, 49 deletions
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index caa011008cd0..7ffa43bd7cf9 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -452,29 +452,85 @@ static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
/* Grant backend access to each skb fragment page. */
for (i = 0; i < frags; i++) {
skb_frag_t *frag = skb_shinfo(skb)->frags + i;
+ struct page *page = skb_frag_page(frag);
- tx->flags |= XEN_NETTXF_more_data;
+ len = skb_frag_size(frag);
+ offset = frag->page_offset;
- id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
- np->tx_skbs[id].skb = skb_get(skb);
- tx = RING_GET_REQUEST(&np->tx, prod++);
- tx->id = id;
- ref = gnttab_claim_grant_reference(&np->gref_tx_head);
- BUG_ON((signed short)ref < 0);
+ /* Data must not cross a page boundary. */
+ BUG_ON(len + offset > PAGE_SIZE<<compound_order(page));
- mfn = pfn_to_mfn(page_to_pfn(skb_frag_page(frag)));
- gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
- mfn, GNTMAP_readonly);
+ /* Skip unused frames from start of page */
+ page += offset >> PAGE_SHIFT;
+ offset &= ~PAGE_MASK;
- tx->gref = np->grant_tx_ref[id] = ref;
- tx->offset = frag->page_offset;
- tx->size = skb_frag_size(frag);
- tx->flags = 0;
+ while (len > 0) {
+ unsigned long bytes;
+
+ BUG_ON(offset >= PAGE_SIZE);
+
+ bytes = PAGE_SIZE - offset;
+ if (bytes > len)
+ bytes = len;
+
+ tx->flags |= XEN_NETTXF_more_data;
+
+ id = get_id_from_freelist(&np->tx_skb_freelist,
+ np->tx_skbs);
+ np->tx_skbs[id].skb = skb_get(skb);
+ tx = RING_GET_REQUEST(&np->tx, prod++);
+ tx->id = id;
+ ref = gnttab_claim_grant_reference(&np->gref_tx_head);
+ BUG_ON((signed short)ref < 0);
+
+ mfn = pfn_to_mfn(page_to_pfn(page));
+ gnttab_grant_foreign_access_ref(ref,
+ np->xbdev->otherend_id,
+ mfn, GNTMAP_readonly);
+
+ tx->gref = np->grant_tx_ref[id] = ref;
+ tx->offset = offset;
+ tx->size = bytes;
+ tx->flags = 0;
+
+ offset += bytes;
+ len -= bytes;
+
+ /* Next frame */
+ if (offset == PAGE_SIZE && len) {
+ BUG_ON(!PageCompound(page));
+ page++;
+ offset = 0;
+ }
+ }
}
np->tx.req_prod_pvt = prod;
}
+/*
+ * Count how many ring slots are required to send the frags of this
+ * skb. Each frag might be a compound page.
+ */
+static int xennet_count_skb_frag_slots(struct sk_buff *skb)
+{
+ int i, frags = skb_shinfo(skb)->nr_frags;
+ int pages = 0;
+
+ for (i = 0; i < frags; i++) {
+ skb_frag_t *frag = skb_shinfo(skb)->frags + i;
+ unsigned long size = skb_frag_size(frag);
+ unsigned long offset = frag->page_offset;
+
+ /* Skip unused frames from start of page */
+ offset &= ~PAGE_MASK;
+
+ pages += PFN_UP(offset + size);
+ }
+
+ return pages;
+}
+
static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
unsigned short id;
@@ -487,23 +543,23 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
grant_ref_t ref;
unsigned long mfn;
int notify;
- int frags = skb_shinfo(skb)->nr_frags;
+ int slots;
unsigned int offset = offset_in_page(data);
unsigned int len = skb_headlen(skb);
unsigned long flags;
- frags += DIV_ROUND_UP(offset + len, PAGE_SIZE);
- if (unlikely(frags > MAX_SKB_FRAGS + 1)) {
- printk(KERN_ALERT "xennet: skb rides the rocket: %d frags\n",
- frags);
- dump_stack();
+ slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
+ xennet_count_skb_frag_slots(skb);
+ if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
+ net_alert_ratelimited(
+ "xennet: skb rides the rocket: %d slots\n", slots);
goto drop;
}
spin_lock_irqsave(&np->tx_lock, flags);
if (unlikely(!netif_carrier_ok(dev) ||
- (frags > 1 && !xennet_can_sg(dev)) ||
+ (slots > 1 && !xennet_can_sg(dev)) ||
netif_needs_gso(skb, netif_skb_features(skb)))) {
spin_unlock_irqrestore(&np->tx_lock, flags);
goto drop;
@@ -959,29 +1015,10 @@ err:
i = xennet_fill_frags(np, skb, &tmpq);
/*
- * Truesize approximates the size of true data plus
- * any supervisor overheads. Adding hypervisor
- * overheads has been shown to significantly reduce
- * achievable bandwidth with the default receive
- * buffer size. It is therefore not wise to account
- * for it here.
- *
- * After alloc_skb(RX_COPY_THRESHOLD), truesize is set
- * to RX_COPY_THRESHOLD + the supervisor
- * overheads. Here, we add the size of the data pulled
- * in xennet_fill_frags().
- *
- * We also adjust for any unused space in the main
- * data area by subtracting (RX_COPY_THRESHOLD -
- * len). This is especially important with drivers
- * which split incoming packets into header and data,
- * using only 66 bytes of the main data area (see the
- * e1000 driver for example.) On such systems,
- * without this last adjustement, our achievable
- * receive throughout using the standard receive
- * buffer size was cut by 25%(!!!).
- */
- skb->truesize += skb->data_len - RX_COPY_THRESHOLD;
+ * Truesize is the actual allocation size, even if the
+ * allocation is only partially used.
+ */
+ skb->truesize += PAGE_SIZE * skb_shinfo(skb)->nr_frags;
skb->len += skb->data_len;
if (rx->flags & XEN_NETRXF_csum_blank)
@@ -1255,7 +1292,7 @@ static const struct net_device_ops xennet_netdev_ops = {
#endif
};
-static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev)
+static struct net_device *xennet_create_dev(struct xenbus_device *dev)
{
int i, err;
struct net_device *netdev;
@@ -1351,8 +1388,8 @@ static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev
* structures and the ring buffers for communication with the backend, and
* inform the backend of the appropriate details for those.
*/
-static int __devinit netfront_probe(struct xenbus_device *dev,
- const struct xenbus_device_id *id)
+static int netfront_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
{
int err;
struct net_device *netdev;
@@ -1911,7 +1948,7 @@ static const struct xenbus_device_id netfront_ids[] = {
};
-static int __devexit xennet_remove(struct xenbus_device *dev)
+static int xennet_remove(struct xenbus_device *dev)
{
struct netfront_info *info = dev_get_drvdata(&dev->dev);
@@ -1934,7 +1971,7 @@ static int __devexit xennet_remove(struct xenbus_device *dev)
static DEFINE_XENBUS_DRIVER(netfront, ,
.probe = netfront_probe,
- .remove = __devexit_p(xennet_remove),
+ .remove = xennet_remove,
.resume = netfront_resume,
.otherend_changed = netback_changed,
);
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-11 18:20:33 +0300