xen-netback: Minor refactoring of netback code

This patch contains a few bits of refactoring before introducing the grant
mapping changes:
- introducing xenvif_tx_pending_slots_available(), as this is used several
  times, and will be used more often
- rename the thread to vifX.Y-guest-rx, to signify it does RX work from the
  guest point of view

Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index ae413a2..9d35845 100644 (file)
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -108,6 +108,15 @@ struct xenvif_rx_meta {
  */
 #define MAX_GRANT_COPY_OPS (MAX_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE)
 
+#define NETBACK_INVALID_HANDLE -1
+
+/* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
+ * the maximum slots a valid packet can use. Now this value is defined
+ * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
+ * all backend.
+ */
+#define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
+
 struct xenvif {
        /* Unique identifier for this interface. */
        domid_t          domid;
@@ -216,7 +225,7 @@ void xenvif_carrier_off(struct xenvif *vif);
 
 int xenvif_tx_action(struct xenvif *vif, int budget);
 
-int xenvif_kthread(void *data);
+int xenvif_kthread_guest_rx(void *data);
 void xenvif_kick_thread(struct xenvif *vif);
 
 /* Determine whether the needed number of slots (req) are available,
@@ -226,6 +235,18 @@ bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed);
 
 void xenvif_stop_queue(struct xenvif *vif);
 
+static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif)
+{
+       return MAX_PENDING_REQS -
+               vif->pending_prod + vif->pending_cons;
+}
+
+static inline bool xenvif_tx_pending_slots_available(struct xenvif *vif)
+{
+       return nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
+               < MAX_PENDING_REQS;
+}
+
 extern bool separate_tx_rx_irq;
 
 #endif /* __XEN_NETBACK__COMMON_H__ */

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 7669d49..bc32627 100644 (file)
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -421,8 +421,8 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
                disable_irq(vif->rx_irq);
        }
 
-       task = kthread_create(xenvif_kthread,
-                             (void *)vif, "%s", vif->dev->name);
+       task = kthread_create(xenvif_kthread_guest_rx,
+                             (void *)vif, "%s-guest-rx", vif->dev->name);
        if (IS_ERR(task)) {
                pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
                err = PTR_ERR(task);

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 43ae4ba..715d810 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -62,14 +62,6 @@ module_param(separate_tx_rx_irq, bool, 0644);
 static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
 module_param(fatal_skb_slots, uint, 0444);
 
-/*
- * To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
- * the maximum slots a valid packet can use. Now this value is defined
- * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
- * all backend.
- */
-#define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
-
 /*
  * If head != INVALID_PENDING_RING_IDX, it means this tx request is head of
  * one or more merged tx requests, otherwise it is the continuation of
@@ -131,12 +123,6 @@ static inline pending_ring_idx_t pending_index(unsigned i)
        return i & (MAX_PENDING_REQS-1);
 }
 
-static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif)
-{
-       return MAX_PENDING_REQS -
-               vif->pending_prod + vif->pending_cons;
-}
-
 bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed)
 {
        RING_IDX prod, cons;
@@ -1116,8 +1102,7 @@ static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget)
        struct sk_buff *skb;
        int ret;
 
-       while ((nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
-               < MAX_PENDING_REQS) &&
+       while (xenvif_tx_pending_slots_available(vif) &&
               (skb_queue_len(&vif->tx_queue) < budget)) {
                struct xen_netif_tx_request txreq;
                struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
@@ -1487,8 +1472,7 @@ static inline int tx_work_todo(struct xenvif *vif)
 {
 
        if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->tx)) &&
-           (nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
-            < MAX_PENDING_REQS))
+           xenvif_tx_pending_slots_available(vif))
                return 1;
 
        return 0;
@@ -1551,7 +1535,7 @@ static void xenvif_start_queue(struct xenvif *vif)
                netif_wake_queue(vif->dev);
 }
 
-int xenvif_kthread(void *data)
+int xenvif_kthread_guest_rx(void *data)
 {
        struct xenvif *vif = data;
        struct sk_buff *skb;