1 files changed, 86 insertions, 36 deletions

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 441b158..d6abf19 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -74,8 +74,8 @@ struct netfront_cb {
 
 #define GRANT_INVALID_REF	0
 
-#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
-#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
+#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
+#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
 
 /* Minimum number of Rx slots (includes slot for GSO metadata). */
 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
@@ -291,7 +291,7 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 		struct sk_buff *skb;
 		unsigned short id;
 		grant_ref_t ref;
-		unsigned long gfn;
+		struct page *page;
 		struct xen_netif_rx_request *req;
 
 		skb = xennet_alloc_one_rx_buffer(queue);
@@ -307,14 +307,13 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 		BUG_ON((signed short)ref < 0);
 		queue->grant_rx_ref[id] = ref;
 
-		gfn = xen_page_to_gfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
+		page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
 
 		req = RING_GET_REQUEST(&queue->rx, req_prod);
-		gnttab_grant_foreign_access_ref(ref,
-						queue->info->xbdev->otherend_id,
-						gfn,
-						0);
-
+		gnttab_page_grant_foreign_access_ref_one(ref,
+							 queue->info->xbdev->otherend_id,
+							 page,
+							 0);
 		req->id = id;
 		req->gref = ref;
 	}
@@ -415,25 +414,33 @@ static void xennet_tx_buf_gc(struct netfront_queue *queue)
 	xennet_maybe_wake_tx(queue);
 }
 
-static struct xen_netif_tx_request *xennet_make_one_txreq(
-	struct netfront_queue *queue, struct sk_buff *skb,
-	struct page *page, unsigned int offset, unsigned int len)
+struct xennet_gnttab_make_txreq {
+	struct netfront_queue *queue;
+	struct sk_buff *skb;
+	struct page *page;
+	struct xen_netif_tx_request *tx; /* Last request */
+	unsigned int size;
+};
+
+static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
+				  unsigned int len, void *data)
 {
+	struct xennet_gnttab_make_txreq *info = data;
 	unsigned int id;
 	struct xen_netif_tx_request *tx;
 	grant_ref_t ref;
-
-	len = min_t(unsigned int, PAGE_SIZE - offset, len);
+	/* convenient aliases */
+	struct page *page = info->page;
+	struct netfront_queue *queue = info->queue;
+	struct sk_buff *skb = info->skb;
 
 	id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
 	tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
 	ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
 	BUG_ON((signed short)ref < 0);
 
-	gnttab_grant_foreign_access_ref(ref,
-					queue->info->xbdev->otherend_id,
-					xen_page_to_gfn(page),
-					GNTMAP_readonly);
+	gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
+					gfn, GNTMAP_readonly);
 
 	queue->tx_skbs[id].skb = skb;
 	queue->grant_tx_page[id] = page;
@@ -445,7 +452,34 @@ static struct xen_netif_tx_request *xennet_make_one_txreq(
 	tx->size = len;
 	tx->flags = 0;
 
-	return tx;
+	info->tx = tx;
+	info->size += tx->size;
+}
+
+static struct xen_netif_tx_request *xennet_make_first_txreq(
+	struct netfront_queue *queue, struct sk_buff *skb,
+	struct page *page, unsigned int offset, unsigned int len)
+{
+	struct xennet_gnttab_make_txreq info = {
+		.queue = queue,
+		.skb = skb,
+		.page = page,
+		.size = 0,
+	};
+
+	gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
+
+	return info.tx;
+}
+
+static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
+				  unsigned int len, void *data)
+{
+	struct xennet_gnttab_make_txreq *info = data;
+
+	info->tx->flags |= XEN_NETTXF_more_data;
+	skb_get(info->skb);
+	xennet_tx_setup_grant(gfn, offset, len, data);
 }
 
 static struct xen_netif_tx_request *xennet_make_txreqs(
@@ -453,20 +487,30 @@ static struct xen_netif_tx_request *xennet_make_txreqs(
 	struct sk_buff *skb, struct page *page,
 	unsigned int offset, unsigned int len)
 {
+	struct xennet_gnttab_make_txreq info = {
+		.queue = queue,
+		.skb = skb,
+		.tx = tx,
+	};
+
 	/* Skip unused frames from start of page */
 	page += offset >> PAGE_SHIFT;
 	offset &= ~PAGE_MASK;
 
 	while (len) {
-		tx->flags |= XEN_NETTXF_more_data;
-		tx = xennet_make_one_txreq(queue, skb_get(skb),
-					   page, offset, len);
+		info.page = page;
+		info.size = 0;
+
+		gnttab_foreach_grant_in_range(page, offset, len,
+					      xennet_make_one_txreq,
+					      &info);
+
 		page++;
 		offset = 0;
-		len -= tx->size;
+		len -= info.size;
 	}
 
-	return tx;
+	return info.tx;
 }
 
 /*
@@ -476,9 +520,10 @@ static struct xen_netif_tx_request *xennet_make_txreqs(
 static int xennet_count_skb_slots(struct sk_buff *skb)
 {
 	int i, frags = skb_shinfo(skb)->nr_frags;
-	int pages;
+	int slots;
 
-	pages = PFN_UP(offset_in_page(skb->data) + skb_headlen(skb));
+	slots = gnttab_count_grant(offset_in_page(skb->data),
+				   skb_headlen(skb));
 
 	for (i = 0; i < frags; i++) {
 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
@@ -488,10 +533,10 @@ static int xennet_count_skb_slots(struct sk_buff *skb)
 		/* Skip unused frames from start of page */
 		offset &= ~PAGE_MASK;
 
-		pages += PFN_UP(offset + size);
+		slots += gnttab_count_grant(offset, size);
 	}
 
-	return pages;
+	return slots;
 }
 
 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
@@ -512,6 +557,8 @@ static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
 	return queue_idx;
 }
 
+#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
+
 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct netfront_info *np = netdev_priv(dev);
@@ -546,7 +593,7 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 	slots = xennet_count_skb_slots(skb);
-	if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
+	if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
 		net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
 				    slots, skb->len);
 		if (skb_linearize(skb))
@@ -567,10 +614,13 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 	/* First request for the linear area. */
-	first_tx = tx = xennet_make_one_txreq(queue, skb,
-					      page, offset, len);
-	page++;
-	offset = 0;
+	first_tx = tx = xennet_make_first_txreq(queue, skb,
+						page, offset, len);
+	offset += tx->size;
+	if (offset == PAGE_SIZE) {
+		page++;
+		offset = 0;
+	}
 	len -= tx->size;
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL)
@@ -732,7 +782,7 @@ static int xennet_get_responses(struct netfront_queue *queue,
 
 	for (;;) {
 		if (unlikely(rx->status < 0 ||
-			     rx->offset + rx->status > PAGE_SIZE)) {
+			     rx->offset + rx->status > XEN_PAGE_SIZE)) {
 			if (net_ratelimit())
 				dev_warn(dev, "rx->offset: %u, size: %d\n",
 					 rx->offset, rx->status);
@@ -1496,7 +1546,7 @@ static int setup_netfront(struct xenbus_device *dev,
 		goto fail;
 	}
 	SHARED_RING_INIT(txs);
-	FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE);
+	FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
 
 	err = xenbus_grant_ring(dev, txs, 1, &gref);
 	if (err < 0)
@@ -1510,7 +1560,7 @@ static int setup_netfront(struct xenbus_device *dev,
 		goto alloc_rx_ring_fail;
 	}
 	SHARED_RING_INIT(rxs);
-	FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
+	FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
 
 	err = xenbus_grant_ring(dev, rxs, 1, &gref);
 	if (err < 0)