/*
* 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 netbk_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)
{
struct gnttab_copy *copy_gop;
struct netbk_rx_meta *meta;
/*
* These variables are used iff get_page_ext returns true,
* in which case they are guaranteed to be initialized.
*/
unsigned int uninitialized_var(group), uninitialized_var(idx);
int foreign = get_page_ext(page, &group, &idx);
unsigned long bytes;
/* Data must not cross a page boundary. */
BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
meta = npo->meta + npo->meta_prod - 1;
/* Skip unused frames from start of page */
page += offset >> PAGE_SHIFT;
offset &= ~PAGE_MASK;
while (size > 0) {
BUG_ON(offset >= PAGE_SIZE);
BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
bytes = PAGE_SIZE - offset;
if (bytes > size)
bytes = size;
if (start_new_rx_buffer(npo->copy_off, bytes, *head)) {
/*
* Netfront requires there to be some data in the head
* buffer.
*/
BUG_ON(*head);
meta = get_next_rx_buffer(vif, npo);
}
if (npo->copy_off + bytes > MAX_BUFFER_OFFSET)
bytes = MAX_BUFFER_OFFSET - npo->copy_off;
copy_gop = npo->copy + npo->copy_prod++;
copy_gop->flags = GNTCOPY_dest_gref;
if (foreign) {
struct xen_netbk *netbk = &xen_netbk[group];
struct pending_tx_info *src_pend;
src_pend = &netbk->pending_tx_info[idx];
copy_gop->source.domid = src_pend->vif->domid;
copy_gop->source.u.ref = src_pend->req.gref;
copy_gop->flags |= GNTCOPY_source_gref;
} else {
void *vaddr = page_address(page);
copy_gop->source.domid = DOMID_SELF;
copy_gop->source.u.gmfn = virt_to_mfn(vaddr);
}
copy_gop->source.offset = offset;
copy_gop->dest.domid = vif->domid;
copy_gop->dest.offset = npo->copy_off;
copy_gop->dest.u.ref = npo->copy_gref;
copy_gop->len = bytes;
npo->copy_off += bytes;
meta->size += bytes;
offset += bytes;
size -= bytes;
/* Next frame */
if (offset == PAGE_SIZE && size) {
BUG_ON(!PageCompound(page));
page++;
offset = 0;
}
/* Leave a gap for the GSO descriptor. */
if (*head && skb_shinfo(skb)->gso_size && !vif->gso_prefix)
vif->rx.req_cons++;
*head = 0; /* There must be something in this buffer now. */
}
}
static void netbk_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)
{
struct gnttab_copy *copy_gop;
struct netbk_rx_meta *meta;
/*
*/
unsigned int uninitialized_var(group), uninitialized_var(idx);
int foreign = get_page_ext(page, &group, &idx);
unsigned long bytes;
/* */
BUG_ON(size + offset > PAGE_SIZE);
meta = npo->meta + npo->meta_prod - 1;
while (size > 0) {
BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
if (start_new_rx_buffer(npo->copy_off, size, *head)) {
/*
*/
BUG_ON(*head);
meta = get_next_rx_buffer(vif, npo);
}
bytes = size;
if (npo->copy_off + bytes > MAX_BUFFER_OFFSET)
bytes = MAX_BUFFER_OFFSET - npo->copy_off;
copy_gop = npo->copy + npo->copy_prod++;
copy_gop->flags = GNTCOPY_dest_gref;
if (foreign) {
struct xen_netbk *netbk = &xen_netbk[group];
struct pending_tx_info *src_pend;
src_pend = &netbk->pending_tx_info[idx];
copy_gop->source.domid = src_pend->vif->domid;
copy_gop->source.u.ref = src_pend->req.gref;
copy_gop->flags |= GNTCOPY_source_gref;
} else {
void *vaddr = page_address(page);
copy_gop->source.domid = DOMID_SELF;
copy_gop->source.u.gmfn = virt_to_mfn(vaddr);
}
copy_gop->source.offset = offset;
copy_gop->dest.domid = vif->domid;
copy_gop->dest.offset = npo->copy_off;
copy_gop->dest.u.ref = npo->copy_gref;
copy_gop->len = bytes;
npo->copy_off += bytes;
meta->size += bytes;
offset += bytes;
size -= bytes;
/* */
if (*head && skb_shinfo(skb)->gso_size && !vif->gso_prefix)
vif->rx.req_cons++;
*head = 0; /* */
}
}
