[PKT_SCHED]: New version of u32 classifier hashing workaround.

This version does not change user visible structures.
Signed-off-by: Jamal Hadi Salim <hadi@znyx.com>
Signed-off-by: David S. Miller <davem@redhat.com>

include/linux/pkt_cls.h

@@ -222,9 +222,6 @@ struct tc_u32_sel
 	unsigned char		flags;
 	unsigned char		offshift;
 	unsigned char		nkeys;
-#ifdef fix_u32_bug
-	unsigned char		fshift;  /* fold shift */
-#endif
 
 	__u16			offmask;
 	__u16			off;

net/sched/cls_u32.c

@@ -72,6 +72,7 @@ struct tc_u_knode
 	struct tcf_police	*police;
 #endif
 #endif
+	u8			fshift;
 	struct tcf_result	res;
 	struct tc_u_hnode	*ht_down;
 	struct tc_u32_sel	sel;
@@ -99,10 +100,10 @@ struct tc_u_common
 
 static struct tc_u_common *u32_list;
 
-static __inline__ unsigned u32_hash_fold(u32 key, struct tc_u32_sel *sel)
+static __inline__ unsigned u32_hash_fold(u32 key, struct tc_u32_sel *sel, u8 fshift)
 {
-#ifdef fix_u32_bug
-	unsigned h = (key & sel->hmask)>>sel->fshift;
+#ifndef fix_u32_bug
+	unsigned h = (key & sel->hmask)>>fshift;
 #else
 	unsigned h = (key & sel->hmask);
 
@@ -206,7 +207,7 @@ static int u32_classify(struct sk_buff *skb, struct tcf_proto *tp, struct tcf_re
 		ht = n->ht_down;
 		sel = 0;
 		if (ht->divisor)
-			sel = ht->divisor&u32_hash_fold(*(u32*)(ptr+n->sel.hoff), &n->sel);
+			sel = ht->divisor&u32_hash_fold(*(u32*)(ptr+n->sel.hoff), &n->sel,n->fshift);
 
 		if (!(n->sel.flags&(TC_U32_VAROFFSET|TC_U32_OFFSET|TC_U32_EAT)))
 			goto next_ht;
@@ -701,6 +702,17 @@ static int u32_change(struct tcf_proto *tp, unsigned long base, u32 handle,
 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
 	n->ht_up = ht;
 	n->handle = handle;
+{
+	u8 i = 0;
+	u32 mask = s->hmask;
+	if (mask) {
+		while (!(mask & 1)) {
+			i++;
+			mask>>=1;
+		}
+	}
+	n->fshift = i;
+}
 	err = u32_set_parms(tp->q, base, ht, n, tb, tca[TCA_RATE-1]);
 	if (err == 0) {
 		struct tc_u_knode **ins;