Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
---
[Resend to actually Cc netdev, sorry.]
---
drivers/net/xen-netback/netback.c | 94 +++++++++++++++++++++++++------------
1 files changed, 64 insertions(+), 30 deletions(-)
diff --git a/drivers/net/xen-netback/netback.c
b/drivers/net/xen-netback/netback.c
index 64828de..f149ce5 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -361,6 +361,49 @@ static bool start_new_rx_buffer(int offset, unsigned long
size, int head)
return false;
}
+struct xen_netbk_count_slot_state {
+ unsigned long copy_off;
+ bool head;
+};
+
+unsigned int xen_netbk_count_frag_slots(struct xenvif *vif,
+ unsigned long offset, unsigned long
size,
+ struct xen_netbk_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
@@ -368,48 +411,39 @@ static bool start_new_rx_buffer(int offset, unsigned long
size, int head)
*/
unsigned int xen_netbk_count_skb_slots(struct xenvif *vif, struct sk_buff
*skb)
{
+ struct xen_netbk_count_slot_state state;
unsigned int count;
- int i, copy_off;
+ unsigned char *data;
+ unsigned i;
- count = DIV_ROUND_UP(skb_headlen(skb), PAGE_SIZE);
+ state.head = true;
+ state.copy_off = 0;
- copy_off = skb_headlen(skb) % PAGE_SIZE;
+ /* 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++;
- 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;
- unsigned long bytes;
-
- offset &= ~PAGE_MASK;
-
- while (size > 0) {
- BUG_ON(offset >= PAGE_SIZE);
- BUG_ON(copy_off > MAX_BUFFER_OFFSET);
-
- bytes = PAGE_SIZE - offset;
-
- if (bytes > size)
- bytes = size;
+ data = skb->data;
+ while (data < skb_tail_pointer(skb)) {
+ unsigned long offset = offset_in_page(data);
+ unsigned long size = PAGE_SIZE - offset;
- if (start_new_rx_buffer(copy_off, bytes, 0)) {
- count++;
- copy_off = 0;
- }
+ if (data + size > skb_tail_pointer(skb))
+ size = skb_tail_pointer(skb) - data;
- if (copy_off + bytes > MAX_BUFFER_OFFSET)
- bytes = MAX_BUFFER_OFFSET - copy_off;
+ count += xen_netbk_count_frag_slots(vif, offset, size, &state);
- copy_off += bytes;
+ data += size;
+ }
- offset += bytes;
- size -= bytes;
+ 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;
- if (offset == PAGE_SIZE)
- offset = 0;
- }
+ count += xen_netbk_count_frag_slots(vif, offset, size, &state);
}
return count;
}
--
1.7.2.5
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
