[PATCH 18/23] KVM: PPC: Book3S HV: Separate out hashing from kvmppc_hv_find_lock_hpte()

[Suraj Jitindar Singh <sjitindarsingh@gmail.com>]

Separate out the hashing function from kvmppc_hv_find_lock_hpte() as
kvmppc_hv_get_hash_value() to allow this function to be reused and
prevent code duplication.

No functional change.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_rm_mmu.c | 60 ++++++++++++++++++++++---------------
 1 file changed, 36 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index a939782d8a5e..c8a379a6f533 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -1162,6 +1162,40 @@ static struct mmio_hpte_cache_entry *
 	return &vcpu->arch.mmio_cache.entry[index];
 }
 
+/*
+ * Given an effective address and a slb entry, work out the hash and the
+ * virtual page number
+ */
+unsigned long kvmppc_hv_get_hash_value(struct kvm_hpt_info *hpt, gva_t eaddr,
+				       unsigned long slb_v, unsigned long *avpn,
+				       unsigned int *pshift_p)
+{
+	unsigned long hash, somask, vsid;
+	unsigned int pshift = 12;
+
+	if (slb_v & SLB_VSID_L)
+		pshift = slb_base_page_shift[(slb_v & SLB_VSID_LP) >> 4];
+	if (slb_v & SLB_VSID_B_1T) {
+		somask = (1UL << 40) - 1;
+		vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT_1T;
+		vsid ^= vsid << 25;
+	} else {
+		somask = (1UL << 28) - 1;
+		vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT;
+	}
+	hash = (vsid ^ ((eaddr & somask) >> pshift)) & kvmppc_hpt_mask(hpt);
+	*avpn = slb_v & ~(somask >> 16);	/* also includes B */
+	*avpn |= (eaddr & somask) >> 16;
+
+	if (pshift >= 24)
+		*avpn &= ~((1UL << (pshift - 16)) - 1);
+	else
+		*avpn &= ~0x7fUL;
+	*pshift_p = pshift;
+
+	return hash;
+}
+
 /* When called from virtmode, this func should be protected by
  * preempt_disable(), otherwise, the holding of HPTE_V_HVLOCK
  * can trigger deadlock issue.
@@ -1171,39 +1205,17 @@ long kvmppc_hv_find_lock_hpte(struct kvm_hpt_info *hpt, gva_t eaddr,
 {
 	unsigned int i;
 	unsigned int pshift;
-	unsigned long somask;
-	unsigned long vsid, hash;
-	unsigned long avpn;
 	__be64 *hpte;
-	unsigned long mask, val;
+	unsigned long hash, mask, val;
 	unsigned long v, r, orig_v;
 
 	/* Get page shift, work out hash and AVPN etc. */
 	mask = SLB_VSID_B | HPTE_V_AVPN | HPTE_V_SECONDARY;
-	val = 0;
-	pshift = 12;
+	hash = kvmppc_hv_get_hash_value(hpt, eaddr, slb_v, &val, &pshift);
 	if (slb_v & SLB_VSID_L) {
 		mask |= HPTE_V_LARGE;
 		val |= HPTE_V_LARGE;
-		pshift = slb_base_page_shift[(slb_v & SLB_VSID_LP) >> 4];
-	}
-	if (slb_v & SLB_VSID_B_1T) {
-		somask = (1UL << 40) - 1;
-		vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT_1T;
-		vsid ^= vsid << 25;
-	} else {
-		somask = (1UL << 28) - 1;
-		vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT;
 	}
-	hash = (vsid ^ ((eaddr & somask) >> pshift)) & kvmppc_hpt_mask(hpt);
-	avpn = slb_v & ~(somask >> 16);	/* also includes B */
-	avpn |= (eaddr & somask) >> 16;
-
-	if (pshift >= 24)
-		avpn &= ~((1UL << (pshift - 16)) - 1);
-	else
-		avpn &= ~0x7fUL;
-	val |= avpn;
 
 	for (;;) {
 		hpte = (__be64 *)(hpt->virt + (hash << 7));
-- 
2.13.6