From 3b249157c03154109d31ec95a3c80203adcf8b70 Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@suse.de>
Date: Mon, 21 Jun 2010 15:25:19 +0200
Subject: [PATCH] KVM: PPC: Use kernel hash function

The linux kernel already provides a hash function. Let's reuse that
instead of reinventing the wheel!

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
 arch/powerpc/kvm/book3s_32_mmu_host.c | 10 ++--------
 arch/powerpc/kvm/book3s_64_mmu_host.c | 11 ++---------
 2 files changed, 4 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c
index 81ca9dba4098..904f5ac78f54 100644
--- a/arch/powerpc/kvm/book3s_32_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_32_mmu_host.c
@@ -19,6 +19,7 @@
  */
 
 #include <linux/kvm_host.h>
+#include <linux/hash.h>
 
 #include <asm/kvm_ppc.h>
 #include <asm/kvm_book3s.h>
@@ -162,14 +163,7 @@ static int kvmppc_mmu_hpte_cache_next(struct kvm_vcpu *vcpu)
  * a hash, so we don't waste cycles on looping */
 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
 {
-	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
+	return hash_64(gvsid, SID_MAP_BITS);
 }
 
 
diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
index eb1d26b64714..4ccdde152c37 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -20,6 +20,7 @@
  */
 
 #include <linux/kvm_host.h>
+#include <linux/hash.h>
 
 #include <asm/kvm_ppc.h>
 #include <asm/kvm_book3s.h>
@@ -144,17 +145,9 @@ static int kvmppc_mmu_hpte_cache_next(struct kvm_vcpu *vcpu)
  * a hash, so we don't waste cycles on looping */
 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
 {
-	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
-		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
+	return hash_64(gvsid, SID_MAP_BITS);
 }
 
-
 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
 {
 	struct kvmppc_sid_map *map;