xen-netback: properly sync TX responses

[linux-2.6-block.git] / drivers / net / xen-netback / netback.c

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index d7503aef599f04bec326900fe918a974e55bc5cc..fab361a250d6054e03a40e451efda2eb3678fda6 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -104,13 +104,12 @@ 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);
 
@@ -208,13 +207,9 @@ 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);
@@ -465,12 +460,7 @@ static void xenvif_get_requests(struct xenvif_queue *queue,
        for (shinfo->nr_frags = 0; nr_slots > 0 && shinfo->nr_frags < MAX_SKB_FRAGS;
             nr_slots--) {
                if (unlikely(!txp->size)) {
-                       unsigned long flags;
-
-                       spin_lock_irqsave(&queue->response_lock, flags);
                        make_tx_response(queue, txp, 0, XEN_NETIF_RSP_OKAY);
-                       push_tx_responses(queue);
-                       spin_unlock_irqrestore(&queue->response_lock, flags);
                        ++txp;
                        continue;
                }
@@ -496,14 +486,8 @@ static void xenvif_get_requests(struct xenvif_queue *queue,
 
                for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots; ++txp) {
                        if (unlikely(!txp->size)) {
-                               unsigned long flags;
-
-                               spin_lock_irqsave(&queue->response_lock, flags);
                                make_tx_response(queue, txp, 0,
                                                 XEN_NETIF_RSP_OKAY);
-                               push_tx_responses(queue);
-                               spin_unlock_irqrestore(&queue->response_lock,
-                                                      flags);
                                continue;
                        }
 
@@ -995,7 +979,6 @@ 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;
                }
 
@@ -1007,7 +990,6 @@ 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;
                }
 
@@ -1433,8 +1415,35 @@ 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;
@@ -1444,8 +1453,8 @@ 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
@@ -1459,32 +1468,19 @@ 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)