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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au
Cc: linuxppc-dev@lists.ozlabs.org,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: [PATCH 01/16] powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group
Date: Fri, 27 Oct 2017 09:38:18 +0530	[thread overview]
Message-ID: <20171027040833.3644-2-aneesh.kumar@linux.vnet.ibm.com> (raw)
In-Reply-To: <20171027040833.3644-1-aneesh.kumar@linux.vnet.ibm.com>

When computing the starting slot number for a hash page table group we used
to do this
hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;

Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we
really don't need to clear then separately.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/mm/dump_hashpagetable.c |  2 +-
 arch/powerpc/mm/hash64_4k.c          |  8 ++++----
 arch/powerpc/mm/hash64_64k.c         | 16 ++++++++--------
 arch/powerpc/mm/hash_utils_64.c      | 10 ++++------
 arch/powerpc/mm/hugepage-hash64.c    |  9 ++++-----
 5 files changed, 21 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/mm/dump_hashpagetable.c b/arch/powerpc/mm/dump_hashpagetable.c
index 5c4c93dcff19..2384d40bfcf4 100644
--- a/arch/powerpc/mm/dump_hashpagetable.c
+++ b/arch/powerpc/mm/dump_hashpagetable.c
@@ -260,7 +260,7 @@ static int pseries_find(unsigned long ea, int psize, bool primary, u64 *v, u64 *
 	/* to check in the secondary hash table, we invert the hash */
 	if (!primary)
 		hash = ~hash;
-	hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 	/* see if we can find an entry in the hpte with this hash */
 	for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) {
 		lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes);
diff --git a/arch/powerpc/mm/hash64_4k.c b/arch/powerpc/mm/hash64_4k.c
index 6fa450c12d6d..975793de0914 100644
--- a/arch/powerpc/mm/hash64_4k.c
+++ b/arch/powerpc/mm/hash64_4k.c
@@ -81,7 +81,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
 		hash = hpt_hash(vpn, shift, ssize);
 
 repeat:
-		hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+		hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 
 		/* Insert into the hash table, primary slot */
 		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, 0,
@@ -90,7 +90,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
 		 * Primary is full, try the secondary
 		 */
 		if (unlikely(slot == -1)) {
-			hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+			hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
 			slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa,
 							rflags,
 							HPTE_V_SECONDARY,
@@ -98,8 +98,8 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
 							MMU_PAGE_4K, ssize);
 			if (slot == -1) {
 				if (mftb() & 0x1)
-					hpte_group = ((hash & htab_hash_mask) *
-						      HPTES_PER_GROUP) & ~0x7UL;
+					hpte_group = (hash & htab_hash_mask) *
+							HPTES_PER_GROUP;
 				mmu_hash_ops.hpte_remove(hpte_group);
 				/*
 				 * FIXME!! Should be try the group from which we removed ?
diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c
index 1a68cb19b0e3..f1eb538721fc 100644
--- a/arch/powerpc/mm/hash64_64k.c
+++ b/arch/powerpc/mm/hash64_64k.c
@@ -163,7 +163,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
 	}
 	hash = hpt_hash(vpn, shift, ssize);
 repeat:
-	hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 
 	/* Insert into the hash table, primary slot */
 	slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, 0,
@@ -172,15 +172,15 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
 	 * Primary is full, try the secondary
 	 */
 	if (unlikely(slot == -1)) {
-		hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+		hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
 		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa,
 						rflags, HPTE_V_SECONDARY,
 						MMU_PAGE_4K, MMU_PAGE_4K,
 						ssize);
 		if (slot == -1) {
 			if (mftb() & 0x1)
-				hpte_group = ((hash & htab_hash_mask) *
-					      HPTES_PER_GROUP) & ~0x7UL;
+				hpte_group = (hash & htab_hash_mask) *
+						HPTES_PER_GROUP;
 			mmu_hash_ops.hpte_remove(hpte_group);
 			/*
 			 * FIXME!! Should be try the group from which we removed ?
@@ -285,7 +285,7 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
 		hash = hpt_hash(vpn, shift, ssize);
 
 repeat:
-		hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+		hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 
 		/* Insert into the hash table, primary slot */
 		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, 0,
@@ -295,7 +295,7 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
 		 * Primary is full, try the secondary
 		 */
 		if (unlikely(slot == -1)) {
-			hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+			hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
 			slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa,
 							rflags,
 							HPTE_V_SECONDARY,
@@ -303,8 +303,8 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
 							MMU_PAGE_64K, ssize);
 			if (slot == -1) {
 				if (mftb() & 0x1)
-					hpte_group = ((hash & htab_hash_mask) *
-						      HPTES_PER_GROUP) & ~0x7UL;
+					hpte_group = (hash & htab_hash_mask) *
+							HPTES_PER_GROUP;
 				mmu_hash_ops.hpte_remove(hpte_group);
 				/*
 				 * FIXME!! Should be try the group from which we removed ?
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 655a5a9a183d..4d4662a77c14 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1723,8 +1723,7 @@ long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
 	long slot;
 
 repeat:
-	hpte_group = ((hash & htab_hash_mask) *
-		       HPTES_PER_GROUP) & ~0x7UL;
+	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 
 	/* Insert into the hash table, primary slot */
 	slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, vflags,
@@ -1732,15 +1731,14 @@ long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
 
 	/* Primary is full, try the secondary */
 	if (unlikely(slot == -1)) {
-		hpte_group = ((~hash & htab_hash_mask) *
-			      HPTES_PER_GROUP) & ~0x7UL;
+		hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
 		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags,
 						vflags | HPTE_V_SECONDARY,
 						psize, psize, ssize);
 		if (slot == -1) {
 			if (mftb() & 0x1)
-				hpte_group = ((hash & htab_hash_mask) *
-					      HPTES_PER_GROUP)&~0x7UL;
+				hpte_group = (hash & htab_hash_mask) *
+						HPTES_PER_GROUP;
 
 			mmu_hash_ops.hpte_remove(hpte_group);
 			goto repeat;
diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c
index f20d16f849c5..01f213d2bcb9 100644
--- a/arch/powerpc/mm/hugepage-hash64.c
+++ b/arch/powerpc/mm/hugepage-hash64.c
@@ -128,7 +128,7 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
 		new_pmd |= H_PAGE_HASHPTE;
 
 repeat:
-		hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+		hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 
 		/* Insert into the hash table, primary slot */
 		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, 0,
@@ -137,16 +137,15 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
 		 * Primary is full, try the secondary
 		 */
 		if (unlikely(slot == -1)) {
-			hpte_group = ((~hash & htab_hash_mask) *
-				      HPTES_PER_GROUP) & ~0x7UL;
+			hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
 			slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa,
 							rflags,
 							HPTE_V_SECONDARY,
 							psize, lpsize, ssize);
 			if (slot == -1) {
 				if (mftb() & 0x1)
-					hpte_group = ((hash & htab_hash_mask) *
-						      HPTES_PER_GROUP) & ~0x7UL;
+					hpte_group = (hash & htab_hash_mask) *
+							HPTES_PER_GROUP;
 
 				mmu_hash_ops.hpte_remove(hpte_group);
 				goto repeat;
-- 
2.13.6

  reply	other threads:[~2017-10-27  4:08 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-27  4:08 [PATCH 00/16] Remove hash page table slot tracking from linux PTE Aneesh Kumar K.V
2017-10-27  4:08 ` Aneesh Kumar K.V [this message]
2017-10-27  4:08 ` [PATCH 02/16] powerpc/mm: Update native_hpte_find to return hash pte Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 03/16] powerpc/pseries: Update hpte find helper to take hash value Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 04/16] powerpc/mm: Add hash invalidate callback Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 05/16] powerpc/mm: use hash_invalidate for __kernel_map_pages() Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 06/16] powerpc/mm: Switch flush_hash_range to not use slot Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 07/16] powerpc/mm: Add hash updatepp callback Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 08/16] powerpc/mm/hash: Don't track hash pte slot number in linux page table Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 09/16] powerpc/mm: Add new firmware feature HASH API Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 10/16] powerpc/kvm/hash: Implement HASH_REMOVE hcall Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 11/16] powerpc/kvm/hash: Implement HASH_PROTECT hcall Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 12/16] powerpc/kvm/hash: Implement HASH_BULK_REMOVE hcall Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 13/16] powerpc/mm/pseries: Use HASH_PROTECT hcall in guest Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 14/16] powerpc/mm/pseries: Use HASH_REMOVE " Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 15/16] powerpc/mm/pseries: Move slot based bulk remove to helper Aneesh Kumar K.V
2017-10-27  4:08 ` [PATCH 16/16] powerpc/mm/pseries: Use HASH_BULK_REMOVE hcall in guest Aneesh Kumar K.V
2017-10-27  4:34 ` [PATCH 00/16] Remove hash page table slot tracking from linux PTE Paul Mackerras
2017-10-27  5:27   ` Aneesh Kumar K.V
2017-10-27  5:41     ` Paul Mackerras
2017-10-30  7:57       ` Aneesh Kumar K.V
2017-10-30 11:49       ` Aneesh Kumar K.V
2017-10-30 13:14         ` Aneesh Kumar K.V
2017-10-30 13:49           ` Aneesh Kumar K.V
2017-11-21  8:41       ` Aneesh Kumar K.V
2017-10-28 22:35     ` Ram Pai
2017-10-29 14:05       ` Aneesh Kumar K.V
2017-10-29 22:04       ` Paul Mackerras
2017-10-30  0:51         ` Ram Pai
2017-11-01  4:46           ` Michael Ellerman
2017-11-01 11:02           ` Paul Mackerras

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