1 files changed, 112 insertions, 63 deletions

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index bf627af723bf..c759ebc56457 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -38,6 +38,7 @@
 #include <linux/if_vlan.h>
 #include <linux/udp.h>
 #include <linux/highmem.h>
+#include <linux/skbuff_ref.h>
 
 #include <net/tcp.h>
 
@@ -104,13 +105,12 @@ bool provides_xdp_headroom = true;
 module_param(provides_xdp_headroom, bool, 0644);
 
 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
-			       u8 status);
+			       s8 status);
 
 static void make_tx_response(struct xenvif_queue *queue,
-			     struct xen_netif_tx_request *txp,
+			     const struct xen_netif_tx_request *txp,
 			     unsigned int extra_count,
-			     s8       st);
-static void push_tx_responses(struct xenvif_queue *queue);
+			     s8 status);
 
 static void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
 
@@ -198,7 +198,8 @@ static void tx_add_credit(struct xenvif_queue *queue)
 
 void xenvif_tx_credit_callback(struct timer_list *t)
 {
-	struct xenvif_queue *queue = from_timer(queue, t, credit_timeout);
+	struct xenvif_queue *queue = timer_container_of(queue, t,
+							credit_timeout);
 	tx_add_credit(queue);
 	xenvif_napi_schedule_or_enable_events(queue);
 }
@@ -208,13 +209,9 @@ static void xenvif_tx_err(struct xenvif_queue *queue,
 			  unsigned int extra_count, RING_IDX end)
 {
 	RING_IDX cons = queue->tx.req_cons;
-	unsigned long flags;
 
 	do {
-		spin_lock_irqsave(&queue->response_lock, flags);
 		make_tx_response(queue, txp, extra_count, XEN_NETIF_RSP_ERROR);
-		push_tx_responses(queue);
-		spin_unlock_irqrestore(&queue->response_lock, flags);
 		if (cons == end)
 			break;
 		RING_COPY_REQUEST(&queue->tx, cons++, txp);
@@ -334,6 +331,7 @@ static int xenvif_count_requests(struct xenvif_queue *queue,
 struct xenvif_tx_cb {
 	u16 copy_pending_idx[XEN_NETBK_LEGACY_SLOTS_MAX + 1];
 	u8 copy_count;
+	u32 split_mask;
 };
 
 #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
@@ -361,6 +359,8 @@ static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
 	struct sk_buff *skb =
 		alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
 			  GFP_ATOMIC | __GFP_NOWARN);
+
+	BUILD_BUG_ON(sizeof(*XENVIF_TX_CB(skb)) > sizeof(skb->cb));
 	if (unlikely(skb == NULL))
 		return NULL;
 
@@ -393,14 +393,16 @@ static void xenvif_get_requests(struct xenvif_queue *queue,
 	struct gnttab_map_grant_ref *gop = queue->tx_map_ops + *map_ops;
 	struct xen_netif_tx_request *txp = first;
 
-	nr_slots = shinfo->nr_frags + 1;
+	nr_slots = shinfo->nr_frags + frag_overflow + 1;
 
 	copy_count(skb) = 0;
+	XENVIF_TX_CB(skb)->split_mask = 0;
 
 	/* Create copy ops for exactly data_len bytes into the skb head. */
 	__skb_put(skb, data_len);
 	while (data_len > 0) {
 		int amount = data_len > txp->size ? txp->size : data_len;
+		bool split = false;
 
 		cop->source.u.ref = txp->gref;
 		cop->source.domid = queue->vif->domid;
@@ -413,6 +415,13 @@ static void xenvif_get_requests(struct xenvif_queue *queue,
 		cop->dest.u.gmfn = virt_to_gfn(skb->data + skb_headlen(skb)
 				               - data_len);
 
+		/* Don't cross local page boundary! */
+		if (cop->dest.offset + amount > XEN_PAGE_SIZE) {
+			amount = XEN_PAGE_SIZE - cop->dest.offset;
+			XENVIF_TX_CB(skb)->split_mask |= 1U << copy_count(skb);
+			split = true;
+		}
+
 		cop->len = amount;
 		cop->flags = GNTCOPY_source_gref;
 
@@ -420,7 +429,8 @@ static void xenvif_get_requests(struct xenvif_queue *queue,
 		pending_idx = queue->pending_ring[index];
 		callback_param(queue, pending_idx).ctx = NULL;
 		copy_pending_idx(skb, copy_count(skb)) = pending_idx;
-		copy_count(skb)++;
+		if (!split)
+			copy_count(skb)++;
 
 		cop++;
 		data_len -= amount;
@@ -441,20 +451,29 @@ static void xenvif_get_requests(struct xenvif_queue *queue,
 			nr_slots--;
 		} else {
 			/* The copy op partially covered the tx_request.
-			 * The remainder will be mapped.
+			 * The remainder will be mapped or copied in the next
+			 * iteration.
 			 */
 			txp->offset += amount;
 			txp->size -= amount;
 		}
 	}
 
-	for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots;
-	     shinfo->nr_frags++, gop++) {
+	for (shinfo->nr_frags = 0; nr_slots > 0 && shinfo->nr_frags < MAX_SKB_FRAGS;
+	     nr_slots--) {
+		if (unlikely(!txp->size)) {
+			make_tx_response(queue, txp, 0, XEN_NETIF_RSP_OKAY);
+			++txp;
+			continue;
+		}
+
 		index = pending_index(queue->pending_cons++);
 		pending_idx = queue->pending_ring[index];
 		xenvif_tx_create_map_op(queue, pending_idx, txp,
 				        txp == first ? extra_count : 0, gop);
 		frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
+		++shinfo->nr_frags;
+		++gop;
 
 		if (txp == first)
 			txp = txfrags;
@@ -462,22 +481,40 @@ static void xenvif_get_requests(struct xenvif_queue *queue,
 			txp++;
 	}
 
-	if (frag_overflow) {
+	if (nr_slots > 0) {
 
 		shinfo = skb_shinfo(nskb);
 		frags = shinfo->frags;
 
-		for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow;
-		     shinfo->nr_frags++, txp++, gop++) {
+		for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots; ++txp) {
+			if (unlikely(!txp->size)) {
+				make_tx_response(queue, txp, 0,
+						 XEN_NETIF_RSP_OKAY);
+				continue;
+			}
+
 			index = pending_index(queue->pending_cons++);
 			pending_idx = queue->pending_ring[index];
 			xenvif_tx_create_map_op(queue, pending_idx, txp, 0,
 						gop);
 			frag_set_pending_idx(&frags[shinfo->nr_frags],
 					     pending_idx);
+			++shinfo->nr_frags;
+			++gop;
 		}
 
-		skb_shinfo(skb)->frag_list = nskb;
+		if (shinfo->nr_frags) {
+			skb_shinfo(skb)->frag_list = nskb;
+			nskb = NULL;
+		}
+	}
+
+	if (nskb) {
+		/* A frag_list skb was allocated but it is no longer needed
+		 * because enough slots were converted to copy ops above or some
+		 * were empty.
+		 */
+		kfree_skb(nskb);
 	}
 
 	(*copy_ops) = cop - queue->tx_copy_ops;
@@ -539,6 +576,13 @@ static int xenvif_tx_check_gop(struct xenvif_queue *queue,
 		pending_idx = copy_pending_idx(skb, i);
 
 		newerr = (*gopp_copy)->status;
+
+		/* Split copies need to be handled together. */
+		if (XENVIF_TX_CB(skb)->split_mask & (1U << i)) {
+			(*gopp_copy)++;
+			if (!newerr)
+				newerr = (*gopp_copy)->status;
+		}
 		if (likely(!newerr)) {
 			/* The first frag might still have this slot mapped */
 			if (i < copy_count(skb) - 1 || !sharedslot)
@@ -668,7 +712,7 @@ static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb)
 		prev_pending_idx = pending_idx;
 
 		txp = &queue->pending_tx_info[pending_idx].req;
-		page = virt_to_page(idx_to_kaddr(queue, pending_idx));
+		page = virt_to_page((void *)idx_to_kaddr(queue, pending_idx));
 		__skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
 		skb->len += txp->size;
 		skb->data_len += txp->size;
@@ -883,11 +927,9 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 		struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
 		struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
 		unsigned int extra_count;
-		u16 pending_idx;
 		RING_IDX idx;
 		int work_to_do;
 		unsigned int data_len;
-		pending_ring_idx_t index;
 
 		if (queue->tx.sring->req_prod - queue->tx.req_cons >
 		    XEN_NETIF_TX_RING_SIZE) {
@@ -939,7 +981,6 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 					 (ret == 0) ?
 					 XEN_NETIF_RSP_OKAY :
 					 XEN_NETIF_RSP_ERROR);
-			push_tx_responses(queue);
 			continue;
 		}
 
@@ -951,7 +992,6 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 
 			make_tx_response(queue, &txreq, extra_count,
 					 XEN_NETIF_RSP_OKAY);
-			push_tx_responses(queue);
 			continue;
 		}
 
@@ -975,17 +1015,12 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 
 		/* No crossing a page as the payload mustn't fragment. */
 		if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) {
-			netdev_err(queue->vif->dev,
-				   "txreq.offset: %u, size: %u, end: %lu\n",
-				   txreq.offset, txreq.size,
-				   (unsigned long)(txreq.offset&~XEN_PAGE_MASK) + txreq.size);
+			netdev_err(queue->vif->dev, "Cross page boundary, txreq.offset: %u, size: %u\n",
+				   txreq.offset, txreq.size);
 			xenvif_fatal_tx_err(queue->vif);
 			break;
 		}
 
-		index = pending_index(queue->pending_cons);
-		pending_idx = queue->pending_ring[index];
-
 		if (ret >= XEN_NETBK_LEGACY_SLOTS_MAX - 1 && data_len < txreq.size)
 			data_len = txreq.size;
 
@@ -1066,10 +1101,6 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 		__skb_queue_tail(&queue->tx_queue, skb);
 
 		queue->tx.req_cons = idx;
-
-		if ((*map_ops >= ARRAY_SIZE(queue->tx_map_ops)) ||
-		    (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops)))
-			break;
 	}
 
 	return;
@@ -1118,9 +1149,7 @@ static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *s
 			BUG();
 
 		offset += len;
-		__skb_frag_set_page(&frags[i], page);
-		skb_frag_off_set(&frags[i], 0);
-		skb_frag_size_set(&frags[i], len);
+		skb_frag_fill_page_desc(&frags[i], page, 0, len);
 	}
 
 	/* Release all the original (foreign) frags. */
@@ -1129,7 +1158,7 @@ static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *s
 	uarg = skb_shinfo(skb)->destructor_arg;
 	/* increase inflight counter to offset decrement in callback */
 	atomic_inc(&queue->inflight_packets);
-	uarg->callback(NULL, uarg, true);
+	uarg->ops->complete(NULL, uarg, true);
 	skb_shinfo(skb)->destructor_arg = NULL;
 
 	/* Fill the skb with the new (local) frags. */
@@ -1251,8 +1280,9 @@ static int xenvif_tx_submit(struct xenvif_queue *queue)
 	return work_done;
 }
 
-void xenvif_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *ubuf_base,
-			      bool zerocopy_success)
+static void xenvif_zerocopy_callback(struct sk_buff *skb,
+				     struct ubuf_info *ubuf_base,
+				     bool zerocopy_success)
 {
 	unsigned long flags;
 	pending_ring_idx_t index;
@@ -1285,6 +1315,10 @@ void xenvif_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *ubuf_base,
 	xenvif_skb_zerocopy_complete(queue);
 }
 
+const struct ubuf_info_ops xenvif_ubuf_ops = {
+	.complete = xenvif_zerocopy_callback,
+};
+
 static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
 {
 	struct gnttab_unmap_grant_ref *gop;
@@ -1388,8 +1422,35 @@ int xenvif_tx_action(struct xenvif_queue *queue, int budget)
 	return work_done;
 }
 
+static void _make_tx_response(struct xenvif_queue *queue,
+			     const struct xen_netif_tx_request *txp,
+			     unsigned int extra_count,
+			     s8 status)
+{
+	RING_IDX i = queue->tx.rsp_prod_pvt;
+	struct xen_netif_tx_response *resp;
+
+	resp = RING_GET_RESPONSE(&queue->tx, i);
+	resp->id     = txp->id;
+	resp->status = status;
+
+	while (extra_count-- != 0)
+		RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
+
+	queue->tx.rsp_prod_pvt = ++i;
+}
+
+static void push_tx_responses(struct xenvif_queue *queue)
+{
+	int notify;
+
+	RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
+	if (notify)
+		notify_remote_via_irq(queue->tx_irq);
+}
+
 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
-			       u8 status)
+			       s8 status)
 {
 	struct pending_tx_info *pending_tx_info;
 	pending_ring_idx_t index;
@@ -1399,8 +1460,8 @@ static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
 
 	spin_lock_irqsave(&queue->response_lock, flags);
 
-	make_tx_response(queue, &pending_tx_info->req,
-			 pending_tx_info->extra_count, status);
+	_make_tx_response(queue, &pending_tx_info->req,
+			  pending_tx_info->extra_count, status);
 
 	/* Release the pending index before pusing the Tx response so
 	 * its available before a new Tx request is pushed by the
@@ -1414,32 +1475,19 @@ static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
 	spin_unlock_irqrestore(&queue->response_lock, flags);
 }
 
-
 static void make_tx_response(struct xenvif_queue *queue,
-			     struct xen_netif_tx_request *txp,
+			     const struct xen_netif_tx_request *txp,
 			     unsigned int extra_count,
-			     s8       st)
+			     s8 status)
 {
-	RING_IDX i = queue->tx.rsp_prod_pvt;
-	struct xen_netif_tx_response *resp;
-
-	resp = RING_GET_RESPONSE(&queue->tx, i);
-	resp->id     = txp->id;
-	resp->status = st;
-
-	while (extra_count-- != 0)
-		RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
+	unsigned long flags;
 
-	queue->tx.rsp_prod_pvt = ++i;
-}
+	spin_lock_irqsave(&queue->response_lock, flags);
 
-static void push_tx_responses(struct xenvif_queue *queue)
-{
-	int notify;
+	_make_tx_response(queue, txp, extra_count, status);
+	push_tx_responses(queue);
 
-	RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
-	if (notify)
-		notify_remote_via_irq(queue->tx_irq);
+	spin_unlock_irqrestore(&queue->response_lock, flags);
 }
 
 static void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
@@ -1737,5 +1785,6 @@ static void __exit netback_fini(void)
 }
 module_exit(netback_fini);
 
+MODULE_DESCRIPTION("Xen backend network device module");
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_ALIAS("xen-backend:vif");