[PATCH v1 1/3] powerpc/32s: Remove unused counters incremented by create_hpte()

[PATCH v1 1/3] powerpc/32s: Remove unused counters incremented by create_hpte()

[Christophe Leroy]

primary_pteg_full and htab_hash_searches are not used.

Remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/book3s32/hash_low.S | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index 9a56ba4f68f2..f964fd34dad9 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -359,11 +359,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
 	beq+	10f			/* no PTE: go look for an empty slot */
 	tlbie	r4
 
-	lis	r4, (htab_hash_searches - PAGE_OFFSET)@ha
-	lwz	r6, (htab_hash_searches - PAGE_OFFSET)@l(r4)
-	addi	r6,r6,1			/* count how many searches we do */
-	stw	r6, (htab_hash_searches - PAGE_OFFSET)@l(r4)
-
 	/* Search the primary PTEG for a PTE whose 1st (d)word matches r5 */
 	mtctr	r0
 	addi	r4,r3,-HPTE_SIZE
@@ -393,12 +388,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
 	bdnzf	2,1b			/* loop while ctr != 0 && !cr0.eq */
 	beq+	.Lfound_empty
 
-	/* update counter of times that the primary PTEG is full */
-	lis	r4, (primary_pteg_full - PAGE_OFFSET)@ha
-	lwz	r6, (primary_pteg_full - PAGE_OFFSET)@l(r4)
-	addi	r6,r6,1
-	stw	r6, (primary_pteg_full - PAGE_OFFSET)@l(r4)
-
 	patch_site	0f, patch__hash_page_C
 	/* Search the secondary PTEG for an empty slot */
 	ori	r5,r5,PTE_H		/* set H (secondary hash) bit */
@@ -491,10 +480,6 @@ _ASM_NOKPROBE_SYMBOL(create_hpte)
 	.align	2
 next_slot:
 	.space	4
-primary_pteg_full:
-	.space	4
-htab_hash_searches:
-	.space	4
 	.previous
 
 /*
-- 
2.25.0

[PATCH v1 2/3] powerpc/32s: In add_hash_page(), calculate VSID later

[Christophe Leroy]

VSID is only for create_hpte(). When _PAGE_HASHPTE is
already set, add_hash_page() bails out without calling
create_hpte() and doesn't need the value of VSID.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/book3s32/hash_low.S | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index f964fd34dad9..1366e8e4fc05 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -188,12 +188,6 @@ _GLOBAL(add_hash_page)
 	mflr	r0
 	stw	r0,4(r1)
 
-	/* Convert context and va to VSID */
-	mulli	r3,r3,897*16		/* multiply context by context skew */
-	rlwinm	r0,r4,4,28,31		/* get ESID (top 4 bits of va) */
-	mulli	r0,r0,0x111		/* multiply by ESID skew */
-	add	r3,r3,r0		/* note create_hpte trims to 24 bits */
-
 #ifdef CONFIG_SMP
 	lwz	r8,TASK_CPU(r2)		/* to go in mmu_hash_lock */
 	oris	r8,r8,12
@@ -257,6 +251,12 @@ _GLOBAL(add_hash_page)
 	stwcx.	r5,0,r8
 	bne-	1b
 
+	/* Convert context and va to VSID */
+	mulli	r3,r3,897*16		/* multiply context by context skew */
+	rlwinm	r0,r4,4,28,31		/* get ESID (top 4 bits of va) */
+	mulli	r0,r0,0x111		/* multiply by ESID skew */
+	add	r3,r3,r0		/* note create_hpte trims to 24 bits */
+
 	bl	create_hpte
 
 9:
-- 
2.25.0

[PATCH v1 3/3] powerpc/32s: Cleanup around PTE_FLAGS_OFFSET in hash_low.S

[Christophe Leroy]

PTE_FLAGS_OFFSET is defined in asm/page_32.h and used only
in hash_low.S

And PTE_FLAGS_OFFSET nullity depends on CONFIG_PTE_64BIT

Instead of tests like #if (PTE_FLAGS_OFFSET != 0), use
CONFIG_PTE_64BIT related code.

Also move the definition of PTE_FLAGS_OFFSET into hash_low.S
directly, that improves readability.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/page_32.h  |  6 ------
 arch/powerpc/mm/book3s32/hash_low.S | 23 +++++++++++++----------
 2 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/include/asm/page_32.h b/arch/powerpc/include/asm/page_32.h
index d64dfe3ac712..56f217606327 100644
--- a/arch/powerpc/include/asm/page_32.h
+++ b/arch/powerpc/include/asm/page_32.h
@@ -16,12 +16,6 @@
 #define ARCH_DMA_MINALIGN	L1_CACHE_BYTES
 #endif
 
-#ifdef CONFIG_PTE_64BIT
-#define PTE_FLAGS_OFFSET	4	/* offset of PTE flags, in bytes */
-#else
-#define PTE_FLAGS_OFFSET	0
-#endif
-
 #if defined(CONFIG_PPC_256K_PAGES) || \
     (defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES))
 #define PTE_SHIFT	(PAGE_SHIFT - PTE_T_LOG2 - 2)	/* 1/4 of a page */
diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index 1366e8e4fc05..f559a931b9a8 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -26,6 +26,12 @@
 #include <asm/feature-fixups.h>
 #include <asm/code-patching-asm.h>
 
+#ifdef CONFIG_PTE_64BIT
+#define PTE_FLAGS_OFFSET	4	/* offset of PTE flags, in bytes */
+#else
+#define PTE_FLAGS_OFFSET	0
+#endif
+
 #ifdef CONFIG_SMP
 	.section .bss
 	.align	2
@@ -94,6 +100,11 @@ _GLOBAL(hash_page)
 	rlwimi	r8,r4,22,20,29		/* insert next 10 bits of address */
 #else
 	rlwimi	r8,r4,23,20,28		/* compute pte address */
+	/*
+	 * If PTE_64BIT is set, the low word is the flags word; use that
+	 * word for locking since it contains all the interesting bits.
+	 */
+	addi	r8,r8,PTE_FLAGS_OFFSET
 #endif
 
 	/*
@@ -101,13 +112,7 @@ _GLOBAL(hash_page)
 	 * because almost always, there won't be a permission violation
 	 * and there won't already be an HPTE, and thus we will have
 	 * to update the PTE to set _PAGE_HASHPTE.  -- paulus.
-	 *
-	 * If PTE_64BIT is set, the low word is the flags word; use that
-	 * word for locking since it contains all the interesting bits.
 	 */
-#if (PTE_FLAGS_OFFSET != 0)
-	addi	r8,r8,PTE_FLAGS_OFFSET
-#endif
 .Lretry:
 	lwarx	r6,0,r8			/* get linux-style pte, flag word */
 #ifdef CONFIG_PPC_KUAP
@@ -511,8 +516,9 @@ _GLOBAL(flush_hash_pages)
 	rlwimi	r5,r4,22,20,29
 #else
 	rlwimi	r5,r4,23,20,28
+	addi	r5,r5,PTE_FLAGS_OFFSET
 #endif
-1:	lwz	r0,PTE_FLAGS_OFFSET(r5)
+1:	lwz	r0,0(r5)
 	cmpwi	cr1,r6,1
 	andi.	r0,r0,_PAGE_HASHPTE
 	bne	2f
@@ -556,9 +562,6 @@ _GLOBAL(flush_hash_pages)
 	 * already clear, we're done (for this pte).  If not,
 	 * clear it (atomically) and proceed.  -- paulus.
 	 */
-#if (PTE_FLAGS_OFFSET != 0)
-	addi	r5,r5,PTE_FLAGS_OFFSET
-#endif
 33:	lwarx	r8,0,r5			/* fetch the pte flags word */
 	andi.	r0,r8,_PAGE_HASHPTE
 	beq	8f			/* done if HASHPTE is already clear */
-- 
2.25.0

Re: [PATCH v1 1/3] powerpc/32s: Remove unused counters incremented by create_hpte()

[Michael Ellerman]

On Tue, 24 Nov 2020 19:51:55 +0000 (UTC), Christophe Leroy wrote:
> primary_pteg_full and htab_hash_searches are not used.
> 
> Remove them.

Applied to powerpc/next.

[1/3] powerpc/32s: Remove unused counters incremented by create_hpte()
      https://git.kernel.org/powerpc/c/c5ccb4e78968fbe64f938a5a012fc8ec25cafabf
[2/3] powerpc/32s: In add_hash_page(), calculate VSID later
      https://git.kernel.org/powerpc/c/fec6166b44ded68e68144144a02e498580118f1a
[3/3] powerpc/32s: Cleanup around PTE_FLAGS_OFFSET in hash_low.S
      https://git.kernel.org/powerpc/c/da481c4fe0e485cdab5cf4d2761be8b8fb38d3d1

cheers