[PKT_SCHED]: GRED: Introduce tc_index_to_dp()

Adds a transformation function returning the DP index for a
given skb according to its tc_index.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

1 files changed, 18 insertions, 9 deletions

diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index 95c5f2cf3fdf..38dab959feed 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -60,6 +60,7 @@
 #endif
 
 #define GRED_DEF_PRIO (MAX_DPs / 2)
+#define GRED_VQ_MASK (MAX_DPs - 1)
 
 struct gred_sched_data;
 struct gred_sched;
@@ -153,6 +154,11 @@ static inline unsigned int gred_backlog(struct gred_sched *table,
                 return q->backlog;
 }
 
+static inline u16 tc_index_to_dp(struct sk_buff *skb)
+{
+        return skb->tc_index & GRED_VQ_MASK;
+}
+
 static int
 gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
 {
@@ -160,14 +166,16 @@ gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
         struct gred_sched *t= qdisc_priv(sch);
         unsigned long qavg = 0;
         int i=0;
+        u16 dp;
 
         if (!t->initd && skb_queue_len(&sch->q) < (sch->dev->tx_queue_len ? : 1)) {
                 D2PRINTK("NO GRED Queues setup yet! Enqueued anyway\n");
                 goto do_enqueue;
         }
 
+        dp = tc_index_to_dp(skb);
 
-        if ( ((skb->tc_index&0xf) > (t->DPs -1)) || !(q=t->tab[skb->tc_index&0xf])) {
+        if (dp >= t->DPs  || (q = t->tab[dp]) == NULL) {
                 printk("GRED: setting to default (%d)\n ",t->def);
                 if (!(q=t->tab[t->def])) {
                         DPRINTK("GRED: setting to default FAILED! dropping!! "
@@ -176,7 +184,7 @@ gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
                 }
                 /* fix tc_index? --could be controvesial but needed for
                    requeueing */
-                skb->tc_index=(skb->tc_index&0xfffffff0) | t->def;
+                skb->tc_index=(skb->tc_index & ~GRED_VQ_MASK) | t->def;
         }
 
         D2PRINTK("gred_enqueue virtualQ 0x%x classid %x backlog %d "
@@ -245,9 +253,8 @@ congestion_drop:
 static int
 gred_requeue(struct sk_buff *skb, struct Qdisc* sch)
 {
-        struct gred_sched_data *q;
-        struct gred_sched *t= qdisc_priv(sch);
-        q= t->tab[(skb->tc_index&0xf)];
+        struct gred_sched *t = qdisc_priv(sch);
+        struct gred_sched_data *q = t->tab[tc_index_to_dp(skb)];
 /* error checking here -- probably unnecessary */
 
         if (red_is_idling(&q->parms))
@@ -267,13 +274,14 @@ gred_dequeue(struct Qdisc* sch)
         skb = qdisc_dequeue_head(sch);
 
         if (skb) {
-                q= t->tab[(skb->tc_index&0xf)];
+                q = t->tab[tc_index_to_dp(skb)];
                 if (q) {
                         q->backlog -= skb->len;
                         if (!q->backlog && !gred_wred_mode(t))
                                 red_start_of_idle_period(&q->parms);
                 } else {
-                        D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); 
+                        D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",
+                                 tc_index_to_dp(skb));
                 }
                 return skb;
         }
@@ -300,14 +308,15 @@ static unsigned int gred_drop(struct Qdisc* sch)
         skb = qdisc_dequeue_tail(sch);
         if (skb) {
                 unsigned int len = skb->len;
-                q= t->tab[(skb->tc_index&0xf)];
+                q = t->tab[tc_index_to_dp(skb)];
                 if (q) {
                         q->backlog -= len;
                         q->stats.other++;
                         if (!q->backlog && !gred_wred_mode(t))
                                 red_start_of_idle_period(&q->parms);
                 } else {
-                        D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); 
+                        D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",
+                                 tc_index_to_dp(skb));
                 }
 
                 qdisc_drop(skb, sch);