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From:   Christophe Leroy <christophe.leroy@c-s.fr>
Subject: [PATCH 5/9] powerpc/book3s/32: Use patch_site to patch hash functions
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Date:   Fri,  9 Nov 2018 17:33:24 +0000 (UTC)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Use patch_sites and the new modify_instruction_site() function
instead of hardcoding hash functions patching.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/book3s/32/mmu-hash.h |  6 +++++
 arch/powerpc/mm/hash_low_32.S                 | 33 ++++++++++++++-----------
 arch/powerpc/mm/ppc_mmu_32.c                  | 35 ++++++++-------------------
 3 files changed, 35 insertions(+), 39 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index e38c91388c40..9662a44c5639 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -83,6 +83,12 @@ typedef struct {
 	unsigned long vdso_base;
 } mm_context_t;
 
+/* patch sites */
+extern s32 patch__hash_page_A0, patch__hash_page_A1, patch__hash_page_A2;
+extern s32 patch__hash_page_B, patch__hash_page_C;
+extern s32 patch__flush_hash_A0, patch__flush_hash_A1, patch__flush_hash_A2;
+extern s32 patch__flush_hash_B;
+
 #endif /* !__ASSEMBLY__ */
 
 /* We happily ignore the smaller BATs on 601, we don't actually use
diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
index 26acf6c8c20c..1e2df3e9f9ea 100644
--- a/arch/powerpc/mm/hash_low_32.S
+++ b/arch/powerpc/mm/hash_low_32.S
@@ -28,6 +28,7 @@
 #include <asm/asm-offsets.h>
 #include <asm/export.h>
 #include <asm/feature-fixups.h>
+#include <asm/code-patching-asm.h>
 
 #ifdef CONFIG_SMP
 	.section .bss
@@ -337,11 +338,13 @@ END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
 	rlwimi	r5,r4,10,26,31		/* put in API (abbrev page index) */
 	SET_V(r5)			/* set V (valid) bit */
 
+	patch_site	0f, patch__hash_page_A0
+	patch_site	1f, patch__hash_page_A1
+	patch_site	2f, patch__hash_page_A2
 	/* Get the address of the primary PTE group in the hash table (r3) */
-_GLOBAL(hash_page_patch_A)
-	addis	r0,r7,Hash_base@h	/* base address of hash table */
-	rlwimi	r0,r3,LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT    /* VSID -> hash */
-	rlwinm	r3,r4,20+LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT /* PI -> hash */
+0:	addis	r0,r7,Hash_base@h	/* base address of hash table */
+1:	rlwimi	r0,r3,LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT    /* VSID -> hash */
+2:	rlwinm	r3,r4,20+LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT /* PI -> hash */
 	xor	r3,r3,r0		/* make primary hash */
 	li	r0,8			/* PTEs/group */
 
@@ -366,10 +369,10 @@ _GLOBAL(hash_page_patch_A)
 	bdnzf	2,1b			/* loop while ctr != 0 && !cr0.eq */
 	beq+	found_slot
 
+	patch_site	0f, patch__hash_page_B
 	/* Search the secondary PTEG for a matching PTE */
 	ori	r5,r5,PTE_H		/* set H (secondary hash) bit */
-_GLOBAL(hash_page_patch_B)
-	xoris	r4,r3,Hash_msk>>16	/* compute secondary hash */
+0:	xoris	r4,r3,Hash_msk>>16	/* compute secondary hash */
 	xori	r4,r4,(-PTEG_SIZE & 0xffff)
 	addi	r4,r4,-HPTE_SIZE
 	mtctr	r0
@@ -393,10 +396,10 @@ _GLOBAL(hash_page_patch_B)
 	addi	r6,r6,1
 	stw	r6,primary_pteg_full@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 */
-_GLOBAL(hash_page_patch_C)
-	xoris	r4,r3,Hash_msk>>16	/* compute secondary hash */
+0:	xoris	r4,r3,Hash_msk>>16	/* compute secondary hash */
 	xori	r4,r4,(-PTEG_SIZE & 0xffff)
 	addi	r4,r4,-HPTE_SIZE
 	mtctr	r0
@@ -577,11 +580,13 @@ _GLOBAL(flush_hash_pages)
 	stwcx.	r8,0,r5			/* update the pte */
 	bne-	33b
 
+	patch_site	0f, patch__flush_hash_A0
+	patch_site	1f, patch__flush_hash_A1
+	patch_site	2f, patch__flush_hash_A2
 	/* Get the address of the primary PTE group in the hash table (r3) */
-_GLOBAL(flush_hash_patch_A)
-	addis	r8,r7,Hash_base@h	/* base address of hash table */
-	rlwimi	r8,r3,LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT    /* VSID -> hash */
-	rlwinm	r0,r4,20+LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT /* PI -> hash */
+0:	addis	r8,r7,Hash_base@h	/* base address of hash table */
+1:	rlwimi	r8,r3,LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT    /* VSID -> hash */
+2:	rlwinm	r0,r4,20+LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT /* PI -> hash */
 	xor	r8,r0,r8		/* make primary hash */
 
 	/* Search the primary PTEG for a PTE whose 1st (d)word matches r5 */
@@ -593,11 +598,11 @@ _GLOBAL(flush_hash_patch_A)
 	bdnzf	2,1b			/* loop while ctr != 0 && !cr0.eq */
 	beq+	3f
 
+	patch_site	0f, patch__flush_hash_B
 	/* Search the secondary PTEG for a matching PTE */
 	ori	r11,r11,PTE_H		/* set H (secondary hash) bit */
 	li	r0,8			/* PTEs/group */
-_GLOBAL(flush_hash_patch_B)
-	xoris	r12,r8,Hash_msk>>16	/* compute secondary hash */
+0:	xoris	r12,r8,Hash_msk>>16	/* compute secondary hash */
 	xori	r12,r12,(-PTEG_SIZE & 0xffff)
 	addi	r12,r12,-HPTE_SIZE
 	mtctr	r0
diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c
index 3c7c73defcb6..cc4b81331167 100644
--- a/arch/powerpc/mm/ppc_mmu_32.c
+++ b/arch/powerpc/mm/ppc_mmu_32.c
@@ -31,6 +31,7 @@
 #include <asm/prom.h>
 #include <asm/mmu.h>
 #include <asm/machdep.h>
+#include <asm/code-patching.h>
 
 #include "mmu_decl.h"
 
@@ -182,10 +183,6 @@ void __init MMU_init_hw(void)
 	unsigned int hmask, mb, mb2;
 	unsigned int n_hpteg, lg_n_hpteg;
 
-	extern unsigned int hash_page_patch_A[];
-	extern unsigned int hash_page_patch_B[], hash_page_patch_C[];
-	extern unsigned int flush_hash_patch_A[], flush_hash_patch_B[];
-
 	if (!mmu_has_feature(MMU_FTR_HPTE_TABLE))
 		return;
 
@@ -234,31 +231,19 @@ void __init MMU_init_hw(void)
 	if (lg_n_hpteg > 16)
 		mb2 = 16 - LG_HPTEG_SIZE;
 
-	hash_page_patch_A[0] = (hash_page_patch_A[0] & ~0xffff)
-		| ((unsigned int)(Hash) >> 16);
-	hash_page_patch_A[1] = (hash_page_patch_A[1] & ~0x7c0) | (mb << 6);
-	hash_page_patch_A[2] = (hash_page_patch_A[2] & ~0x7c0) | (mb2 << 6);
-	hash_page_patch_B[0] = (hash_page_patch_B[0] & ~0xffff) | hmask;
-	hash_page_patch_C[0] = (hash_page_patch_C[0] & ~0xffff) | hmask;
-
-	/*
-	 * Ensure that the locations we've patched have been written
-	 * out from the data cache and invalidated in the instruction
-	 * cache, on those machines with split caches.
-	 */
-	flush_icache_range((unsigned long) &hash_page_patch_A[0],
-			   (unsigned long) &hash_page_patch_C[1]);
+	modify_instruction_site(&patch__hash_page_A0, 0xffff, (unsigned int)Hash >> 16);
+	modify_instruction_site(&patch__hash_page_A1, 0x7c0, mb << 6);
+	modify_instruction_site(&patch__hash_page_A2, 0x7c0, mb2 << 6);
+	modify_instruction_site(&patch__hash_page_B, 0xffff, hmask);
+	modify_instruction_site(&patch__hash_page_C, 0xffff, hmask);
 
 	/*
 	 * Patch up the instructions in hashtable.S:flush_hash_page
 	 */
-	flush_hash_patch_A[0] = (flush_hash_patch_A[0] & ~0xffff)
-		| ((unsigned int)(Hash) >> 16);
-	flush_hash_patch_A[1] = (flush_hash_patch_A[1] & ~0x7c0) | (mb << 6);
-	flush_hash_patch_A[2] = (flush_hash_patch_A[2] & ~0x7c0) | (mb2 << 6);
-	flush_hash_patch_B[0] = (flush_hash_patch_B[0] & ~0xffff) | hmask;
-	flush_icache_range((unsigned long) &flush_hash_patch_A[0],
-			   (unsigned long) &flush_hash_patch_B[1]);
+	modify_instruction_site(&patch__flush_hash_A0, 0xffff, (unsigned int)Hash >> 16);
+	modify_instruction_site(&patch__flush_hash_A1, 0x7c0, mb << 6);
+	modify_instruction_site(&patch__flush_hash_A2, 0x7c0, mb2 << 6);
+	modify_instruction_site(&patch__flush_hash_B, 0xffff, hmask);
 
 	if ( ppc_md.progress ) ppc_md.progress("hash:done", 0x205);
 }
-- 
2.13.3