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>
git-mirror · Aug 1, 2010 · 3b24915 · 3b24915
1 parent a576f7a
commit 3b24915
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Showing 2 changed files with 4 additions and 17 deletions.
diff --git 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
@@ -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;