Merge.

diff --git a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
index 05b876e93ca6600b39fd8c500d53ea18afd6c53d..1db6bbc9d71e45a018c89a138277a3e38901aa56 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
@@ -99,17 +99,17 @@ struct netfront_info {
        struct timer_list rx_refill_timer;
 
        /*
-        * {tx,rx}_skbs store outstanding skbuffs. The first entry in each
-        * array is an index into a chain of free entries.
+        * {tx,rx}_skbs store outstanding skbuffs. The first entry in tx_skbs
+        * is an index into a chain of free entries.
         */
        struct sk_buff *tx_skbs[NET_TX_RING_SIZE+1];
-       struct sk_buff *rx_skbs[NET_RX_RING_SIZE+1];
+       struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
 
 #define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
        grant_ref_t gref_tx_head;
        grant_ref_t grant_tx_ref[NET_TX_RING_SIZE + 1];
        grant_ref_t gref_rx_head;
-       grant_ref_t grant_rx_ref[NET_TX_RING_SIZE + 1];
+       grant_ref_t grant_rx_ref[NET_TX_RING_SIZE];
 
        struct xenbus_device *xbdev;
        int tx_ring_ref;
@@ -122,7 +122,7 @@ struct netfront_info {
 };
 
 /*
- * Access macros for acquiring freeing slots in {tx,rx}_skbs[].
+ * Access macros for acquiring freeing slots in tx_skbs[].
  */
 
 static inline void add_id_to_freelist(struct sk_buff **list, unsigned short id)
@@ -138,6 +138,29 @@ static inline unsigned short get_id_from_freelist(struct sk_buff **list)
        return id;
 }
 
+static inline int xennet_rxidx(RING_IDX idx)
+{
+       return idx & (NET_RX_RING_SIZE - 1);
+}
+
+static inline struct sk_buff *xennet_get_rx_skb(struct netfront_info *np,
+                                               RING_IDX ri)
+{
+       int i = xennet_rxidx(ri);
+       struct sk_buff *skb = np->rx_skbs[i];
+       np->rx_skbs[i] = NULL;
+       return skb;
+}
+
+static inline grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
+                                           RING_IDX ri)
+{
+       int i = xennet_rxidx(ri);
+       grant_ref_t ref = np->grant_rx_ref[i];
+       np->grant_rx_ref[i] = GRANT_INVALID_REF;
+       return ref;
+}
+
 #define DPRINTK(fmt, args...)                          \
        pr_debug("netfront (%s:%d) " fmt,               \
                 __FUNCTION__, __LINE__, ##args)
@@ -598,8 +621,9 @@ static void network_alloc_rx_buffers(struct net_device *dev)
 
                skb->dev = dev;
 
-               id = get_id_from_freelist(np->rx_skbs);
+               id = xennet_rxidx(req_prod + i);
 
+               BUG_ON(np->rx_skbs[id]);
                np->rx_skbs[id] = skb;
 
                RING_GET_REQUEST(&np->rx, req_prod + i)->id = id;
@@ -840,6 +864,19 @@ static irqreturn_t netif_int(int irq, void *dev_id, struct pt_regs *ptregs)
        return IRQ_HANDLED;
 }
 
+static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
+                               grant_ref_t ref)
+{
+       int new = xennet_rxidx(np->rx.req_prod_pvt);
+
+       BUG_ON(np->rx_skbs[new]);
+       np->rx_skbs[new] = skb;
+       np->grant_rx_ref[new] = ref;
+       RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
+       RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
+       np->rx.req_prod_pvt++;
+       RING_PUSH_REQUESTS(&np->rx);
+}
 
 static int netif_poll(struct net_device *dev, int *pbudget)
 {
@@ -874,12 +911,15 @@ static int netif_poll(struct net_device *dev, int *pbudget)
             i++, work_done++) {
                rx = RING_GET_RESPONSE(&np->rx, i);
 
+               skb = xennet_get_rx_skb(np, i);
+               ref = xennet_get_rx_ref(np, i);
+
                /*
                 * This definitely indicates a bug, either in this driver or in
                 * the backend driver. In future this should flag the bad
                 * situation to the system controller to reboot the backed.
                 */
-               if ((ref = np->grant_rx_ref[rx->id]) == GRANT_INVALID_REF) {
+               if (ref == GRANT_INVALID_REF) {
                        WPRINTK("Bad rx response id %d.\n", rx->id);
                        work_done--;
                        continue;
@@ -890,21 +930,12 @@ static int netif_poll(struct net_device *dev, int *pbudget)
                        if (net_ratelimit())
                                WPRINTK("Unfulfilled rx req (id=%d, st=%d).\n",
                                        rx->id, rx->status);
-                       RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id =
-                               rx->id;
-                       RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref =
-                               ref;
-                       np->rx.req_prod_pvt++;
-                       RING_PUSH_REQUESTS(&np->rx);
+                       xennet_move_rx_slot(np, skb, ref);
                        work_done--;
                        continue;
                }
 
                gnttab_release_grant_reference(&np->gref_rx_head, ref);
-               np->grant_rx_ref[rx->id] = GRANT_INVALID_REF;
-
-               skb = np->rx_skbs[rx->id];
-               add_id_to_freelist(np->rx_skbs, rx->id);
 
                /* NB. We handle skb overflow later. */
                skb->data = skb->head + rx->offset;
@@ -1158,15 +1189,23 @@ static void network_connect(struct net_device *dev)
        }
 
        /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
-       for (requeue_idx = 0, i = 1; i <= NET_RX_RING_SIZE; i++) {
-               if ((unsigned long)np->rx_skbs[i] < PAGE_OFFSET)
+       for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
+               if (!np->rx_skbs[i])
                        continue;
+
                gnttab_grant_foreign_transfer_ref(
                        np->grant_rx_ref[i], np->xbdev->otherend_id,
                        __pa(np->rx_skbs[i]->data) >> PAGE_SHIFT);
                RING_GET_REQUEST(&np->rx, requeue_idx)->gref =
                        np->grant_rx_ref[i];
-               RING_GET_REQUEST(&np->rx, requeue_idx)->id = i;
+               RING_GET_REQUEST(&np->rx, requeue_idx)->id = requeue_idx;
+
+               if (requeue_idx < i) {
+                       np->rx_skbs[requeue_idx] = np->rx_skbs[i];
+                       np->grant_rx_ref[requeue_idx] = np->grant_rx_ref[i];
+                       np->rx_skbs[i] = NULL;
+                       np->grant_rx_ref[i] = GRANT_INVALID_REF;
+               }
                requeue_idx++;
        }
 
@@ -1392,8 +1431,8 @@ static struct net_device * __devinit create_netdev(int handle,
                np->grant_tx_ref[i] = GRANT_INVALID_REF;
        }
 
-       for (i = 0; i <= NET_RX_RING_SIZE; i++) {
-               np->rx_skbs[i] = (void *)((unsigned long) i+1);
+       for (i = 0; i < NET_RX_RING_SIZE; i++) {
+               np->rx_skbs[i] = NULL;
                np->grant_rx_ref[i] = GRANT_INVALID_REF;
        }