#include <asm/xen/hypercall.h>
#include <asm/xen/page.h>
-/* SKB control block overlay is used to store useful information when
- * doing guest RX.
- */
-struct skb_cb_overlay {
- int meta_slots_used;
- int peek_slots_count;
-};
-
/* Provide an option to disable split event channels at load time as
* event channels are limited resource. Split event channels are
* enabled by default.
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
*/
unsigned int xenvif_count_skb_slots(struct xenvif *vif, struct sk_buff *skb)
{
+ struct xenvif_count_slot_state state;
unsigned int count;
- int i, copy_off;
- struct skb_cb_overlay *sco;
+ 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 += xenvif_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 += xenvif_count_frag_slots(vif, offset, size, &state);
}
-
- sco = (struct skb_cb_overlay *)skb->cb;
- sco->peek_slots_count = count;
return count;
}
return meta;
}
-/* Set up the grant operations for this fragment. */
+/*
+ * Set up the grant operations for this fragment. If it's a flipping
+ * interface, we also set up the unmap request from here.
+ */
static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
struct netrx_pending_operations *npo,
struct page *page, unsigned long size,
- unsigned long offset, int head, int *first)
+ unsigned long offset, int *head)
{
struct gnttab_copy *copy_gop;
struct xenvif_rx_meta *meta;
if (bytes > size)
bytes = size;
- if (start_new_rx_buffer(npo->copy_off, bytes, head)) {
+ if (start_new_rx_buffer(npo->copy_off, bytes, *head)) {
/*
* Netfront requires there to be some data in the head
* buffer.
*/
- BUG_ON(*first);
+ BUG_ON(*head);
meta = get_next_rx_buffer(vif, npo);
}
}
/* Leave a gap for the GSO descriptor. */
- if (*first && skb_shinfo(skb)->gso_size && !vif->gso_prefix)
+ if (*head && skb_shinfo(skb)->gso_size && !vif->gso_prefix)
vif->rx.req_cons++;
- *first = 0; /* There must be something in this buffer now. */
+ *head = 0; /* There must be something in this buffer now. */
}
}
struct xen_netif_rx_request *req;
struct xenvif_rx_meta *meta;
unsigned char *data;
- int first = 1;
+ int head = 1;
int old_meta_prod;
old_meta_prod = npo->meta_prod;
len = skb_tail_pointer(skb) - data;
xenvif_gop_frag_copy(vif, skb, npo,
- virt_to_page(data), len, offset, 1, &first);
+ virt_to_page(data), len, offset, &head);
data += len;
}
skb_frag_page(&skb_shinfo(skb)->frags[i]),
skb_frag_size(&skb_shinfo(skb)->frags[i]),
skb_shinfo(skb)->frags[i].page_offset,
- 0, &first);
+ &head);
}
return npo->meta_prod - old_meta_prod;
}
}
+struct skb_cb_overlay {
+ int meta_slots_used;
+};
+
static void xenvif_kick_thread(struct xenvif *vif)
{
wake_up(&vif->wq);
count = 0;
while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) {
- RING_IDX old_rx_req_cons;
-
vif = netdev_priv(skb->dev);
nr_frags = skb_shinfo(skb)->nr_frags;
- old_rx_req_cons = vif->rx.req_cons;
sco = (struct skb_cb_overlay *)skb->cb;
sco->meta_slots_used = xenvif_gop_skb(skb, &npo);
- count += vif->rx.req_cons - old_rx_req_cons;
+ count += nr_frags + 1;
__skb_queue_tail(&rxq, skb);
- skb = skb_peek(&vif->rx_queue);
- if (skb == NULL)
- break;
- sco = (struct skb_cb_overlay *)skb->cb;
-
/* Filled the batch queue? */
- if (count + sco->peek_slots_count >= XEN_NETIF_RX_RING_SIZE)
+ /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */
+ if (count + MAX_SKB_FRAGS >= XEN_NETIF_RX_RING_SIZE)
break;
}
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