Merge branch 'xen-netfront-next'
David Vrabel says: ==================== xen-netfront: refactor making Tx requests As netfront as evolved to handle different sorts of skbs the code to fill a Tx requests has been copy and pasted several times. The series refactors this and a few other areas. The first patch is to a Xen header but this can be merged via net-next. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
commit
6a38cc2be6
@ -421,109 +421,68 @@ static void xennet_tx_buf_gc(struct netfront_queue *queue)
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xennet_maybe_wake_tx(queue);
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}
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static void xennet_make_frags(struct sk_buff *skb, struct netfront_queue *queue,
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struct xen_netif_tx_request *tx)
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static struct xen_netif_tx_request *xennet_make_one_txreq(
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struct netfront_queue *queue, struct sk_buff *skb,
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struct page *page, unsigned int offset, unsigned int len)
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{
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char *data = skb->data;
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unsigned long mfn;
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RING_IDX prod = queue->tx.req_prod_pvt;
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int frags = skb_shinfo(skb)->nr_frags;
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unsigned int offset = offset_in_page(data);
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unsigned int len = skb_headlen(skb);
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unsigned int id;
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struct xen_netif_tx_request *tx;
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grant_ref_t ref;
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int i;
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/* While the header overlaps a page boundary (including being
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larger than a page), split it it into page-sized chunks. */
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while (len > PAGE_SIZE - offset) {
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tx->size = PAGE_SIZE - offset;
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len = min_t(unsigned int, PAGE_SIZE - offset, len);
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id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
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tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
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ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
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BUG_ON((signed short)ref < 0);
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gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
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page_to_mfn(page), GNTMAP_readonly);
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queue->tx_skbs[id].skb = skb;
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queue->grant_tx_page[id] = page;
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queue->grant_tx_ref[id] = ref;
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tx->id = id;
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tx->gref = ref;
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tx->offset = offset;
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tx->size = len;
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tx->flags = 0;
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return tx;
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}
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static struct xen_netif_tx_request *xennet_make_txreqs(
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struct netfront_queue *queue, struct xen_netif_tx_request *tx,
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struct sk_buff *skb, struct page *page,
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unsigned int offset, unsigned int len)
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{
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/* Skip unused frames from start of page */
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page += offset >> PAGE_SHIFT;
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offset &= ~PAGE_MASK;
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while (len) {
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tx->flags |= XEN_NETTXF_more_data;
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len -= tx->size;
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data += tx->size;
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tx = xennet_make_one_txreq(queue, skb_get(skb),
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page, offset, len);
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page++;
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offset = 0;
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id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
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queue->tx_skbs[id].skb = skb_get(skb);
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tx = RING_GET_REQUEST(&queue->tx, prod++);
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tx->id = id;
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ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
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BUG_ON((signed short)ref < 0);
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mfn = virt_to_mfn(data);
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gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
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mfn, GNTMAP_readonly);
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queue->grant_tx_page[id] = virt_to_page(data);
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tx->gref = queue->grant_tx_ref[id] = ref;
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tx->offset = offset;
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tx->size = len;
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tx->flags = 0;
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len -= tx->size;
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}
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/* Grant backend access to each skb fragment page. */
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for (i = 0; i < frags; i++) {
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skb_frag_t *frag = skb_shinfo(skb)->frags + i;
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struct page *page = skb_frag_page(frag);
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len = skb_frag_size(frag);
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offset = frag->page_offset;
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/* Skip unused frames from start of page */
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page += offset >> PAGE_SHIFT;
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offset &= ~PAGE_MASK;
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while (len > 0) {
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unsigned long bytes;
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bytes = PAGE_SIZE - offset;
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if (bytes > len)
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bytes = len;
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tx->flags |= XEN_NETTXF_more_data;
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id = get_id_from_freelist(&queue->tx_skb_freelist,
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queue->tx_skbs);
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queue->tx_skbs[id].skb = skb_get(skb);
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tx = RING_GET_REQUEST(&queue->tx, prod++);
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tx->id = id;
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ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
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BUG_ON((signed short)ref < 0);
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mfn = pfn_to_mfn(page_to_pfn(page));
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gnttab_grant_foreign_access_ref(ref,
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queue->info->xbdev->otherend_id,
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mfn, GNTMAP_readonly);
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queue->grant_tx_page[id] = page;
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tx->gref = queue->grant_tx_ref[id] = ref;
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tx->offset = offset;
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tx->size = bytes;
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tx->flags = 0;
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offset += bytes;
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len -= bytes;
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/* Next frame */
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if (offset == PAGE_SIZE && len) {
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BUG_ON(!PageCompound(page));
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page++;
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offset = 0;
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}
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}
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}
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queue->tx.req_prod_pvt = prod;
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return tx;
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}
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/*
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* Count how many ring slots are required to send the frags of this
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* skb. Each frag might be a compound page.
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* Count how many ring slots are required to send this skb. Each frag
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* might be a compound page.
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*/
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static int xennet_count_skb_frag_slots(struct sk_buff *skb)
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static int xennet_count_skb_slots(struct sk_buff *skb)
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{
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int i, frags = skb_shinfo(skb)->nr_frags;
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int pages = 0;
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int pages;
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pages = PFN_UP(offset_in_page(skb->data) + skb_headlen(skb));
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for (i = 0; i < frags; i++) {
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skb_frag_t *frag = skb_shinfo(skb)->frags + i;
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@ -559,18 +518,15 @@ static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
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static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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unsigned short id;
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struct netfront_info *np = netdev_priv(dev);
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struct netfront_stats *stats = this_cpu_ptr(np->stats);
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struct xen_netif_tx_request *tx;
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char *data = skb->data;
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RING_IDX i;
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grant_ref_t ref;
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unsigned long mfn;
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struct xen_netif_tx_request *tx, *first_tx;
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unsigned int i;
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int notify;
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int slots;
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unsigned int offset = offset_in_page(data);
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unsigned int len = skb_headlen(skb);
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struct page *page;
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unsigned int offset;
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unsigned int len;
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unsigned long flags;
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struct netfront_queue *queue = NULL;
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unsigned int num_queues = dev->real_num_tx_queues;
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@ -593,18 +549,18 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
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goto drop;
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}
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slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
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xennet_count_skb_frag_slots(skb);
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slots = xennet_count_skb_slots(skb);
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if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
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net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
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slots, skb->len);
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if (skb_linearize(skb))
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goto drop;
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data = skb->data;
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offset = offset_in_page(data);
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len = skb_headlen(skb);
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}
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page = virt_to_page(skb->data);
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offset = offset_in_page(skb->data);
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len = skb_headlen(skb);
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spin_lock_irqsave(&queue->tx_lock, flags);
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if (unlikely(!netif_carrier_ok(dev) ||
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@ -614,25 +570,13 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
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goto drop;
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}
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i = queue->tx.req_prod_pvt;
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/* First request for the linear area. */
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first_tx = tx = xennet_make_one_txreq(queue, skb,
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page, offset, len);
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page++;
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offset = 0;
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len -= tx->size;
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id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
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queue->tx_skbs[id].skb = skb;
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tx = RING_GET_REQUEST(&queue->tx, i);
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tx->id = id;
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ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
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BUG_ON((signed short)ref < 0);
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mfn = virt_to_mfn(data);
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gnttab_grant_foreign_access_ref(
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ref, queue->info->xbdev->otherend_id, mfn, GNTMAP_readonly);
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queue->grant_tx_page[id] = virt_to_page(data);
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tx->gref = queue->grant_tx_ref[id] = ref;
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tx->offset = offset;
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tx->size = len;
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tx->flags = 0;
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if (skb->ip_summed == CHECKSUM_PARTIAL)
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/* local packet? */
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tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
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@ -640,11 +584,12 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
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/* remote but checksummed. */
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tx->flags |= XEN_NETTXF_data_validated;
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/* Optional extra info after the first request. */
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if (skb_shinfo(skb)->gso_size) {
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struct xen_netif_extra_info *gso;
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gso = (struct xen_netif_extra_info *)
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RING_GET_REQUEST(&queue->tx, ++i);
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RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
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tx->flags |= XEN_NETTXF_extra_info;
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@ -659,10 +604,19 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
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gso->flags = 0;
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}
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queue->tx.req_prod_pvt = i + 1;
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/* Requests for the rest of the linear area. */
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tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
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xennet_make_frags(skb, queue, tx);
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tx->size = skb->len;
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/* Requests for all the frags. */
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for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
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skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
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tx = xennet_make_txreqs(queue, tx, skb,
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skb_frag_page(frag), frag->page_offset,
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skb_frag_size(frag));
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}
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/* First request has the packet length. */
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first_tx->size = skb->len;
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RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
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if (notify)
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@ -3,6 +3,11 @@
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#include <asm/xen/page.h>
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static inline unsigned long page_to_mfn(struct page *page)
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{
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return pfn_to_mfn(page_to_pfn(page));
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}
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struct xen_memory_region {
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phys_addr_t start;
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phys_addr_t size;
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