[PATCH v1 1/8] powerpc/32s: Always map kernel text and rodata with BATs

[PATCH v1 1/8] powerpc/32s: Always map kernel text and rodata with BATs

[Christophe Leroy]

Since commit 2b279c0348af ("powerpc/32s: Allow mapping with BATs with
DEBUG_PAGEALLOC"), there is no real situation where mapping without
BATs is required.

In order to simplify memory handling, always map kernel text
and rodata with BATs even when "nobats" kernel parameter is set.

Also fix the 603 TLB miss exceptions that don't require anymore
kernel page table if DEBUG_PAGEALLOC.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_book3s_32.S | 4 ++--
 arch/powerpc/mm/book3s32/mmu.c       | 8 +++-----
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index a0dda2a1f2df..27767f3e7ec1 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -453,13 +453,13 @@ InstructionTLBMiss:
  */
 	/* Get PTE (linux-style) and check access */
 	mfspr	r3,SPRN_IMISS
-#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC)
+#ifdef CONFIG_MODULES
 	lis	r1, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r1,r3
 #endif
 	mfspr	r2, SPRN_SPRG_PGDIR
 	li	r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
-#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC)
+#ifdef CONFIG_MODULES
 	bgt-	112f
 	lis	r2, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
 	addi	r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l	/* kernel page table */
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index a59e7ec98180..5c60dcade90a 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -157,11 +157,9 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
 	unsigned long done;
 	unsigned long border = (unsigned long)__init_begin - PAGE_OFFSET;
 
-	if (__map_without_bats) {
-		pr_debug("RAM mapped without BATs\n");
-		return base;
-	}
-	if (debug_pagealloc_enabled()) {
+
+	if (debug_pagealloc_enabled() || __map_without_bats) {
+		pr_debug_once("Read-Write memory mapped without BATs\n");
 		if (base >= border)
 			return base;
 		if (top >= border)
-- 
2.25.0

[PATCH v1 1/8] powerpc/32s: Always map kernel text and rodata with BATs

[Christophe Leroy]

Since commit 2b279c0348af ("powerpc/32s: Allow mapping with BATs with
DEBUG_PAGEALLOC"), there is no real situation where mapping without
BATs is required.

In order to simplify memory handling, always map kernel text
and rodata with BATs even when "nobats" kernel parameter is set.

Also fix the 603 TLB miss exceptions that don't require anymore
kernel page table if DEBUG_PAGEALLOC.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_book3s_32.S | 4 ++--
 arch/powerpc/mm/book3s32/mmu.c       | 8 +++-----
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index a0dda2a1f2df..27767f3e7ec1 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -453,13 +453,13 @@ InstructionTLBMiss:
  */
 	/* Get PTE (linux-style) and check access */
 	mfspr	r3,SPRN_IMISS
-#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC)
+#ifdef CONFIG_MODULES
 	lis	r1, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r1,r3
 #endif
 	mfspr	r2, SPRN_SPRG_PGDIR
 	li	r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
-#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC)
+#ifdef CONFIG_MODULES
 	bgt-	112f
 	lis	r2, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
 	addi	r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l	/* kernel page table */
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index a59e7ec98180..5c60dcade90a 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -157,11 +157,9 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
 	unsigned long done;
 	unsigned long border = (unsigned long)__init_begin - PAGE_OFFSET;
 
-	if (__map_without_bats) {
-		pr_debug("RAM mapped without BATs\n");
-		return base;
-	}
-	if (debug_pagealloc_enabled()) {
+
+	if (debug_pagealloc_enabled() || __map_without_bats) {
+		pr_debug_once("Read-Write memory mapped without BATs\n");
 		if (base >= border)
 			return base;
 		if (top >= border)
-- 
2.25.0

[PATCH v1 2/8] powerpc/32s: Don't hash_preload() kernel text

[Christophe Leroy]

We now always map kernel text with BATs. Neither need to preload
hash with kernel text addresses nor ensure they are never evicted.

This is more or less a revert of commit ee4f2ea48674 ("[POWERPC] Fix
32-bit mm operations when not using BATs")

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/book3s32/hash_low.S | 18 +-----------------
 arch/powerpc/mm/book3s32/mmu.c      |  2 +-
 arch/powerpc/mm/mmu_decl.h          |  2 --
 arch/powerpc/mm/pgtable_32.c        |  4 ----
 4 files changed, 2 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index b2c912e517b9..48415c857d80 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -411,30 +411,14 @@ END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
 	 * and we know there is a definite (although small) speed
 	 * advantage to putting the PTE in the primary PTEG, we always
 	 * put the PTE in the primary PTEG.
-	 *
-	 * In addition, we skip any slot that is mapping kernel text in
-	 * order to avoid a deadlock when not using BAT mappings if
-	 * trying to hash in the kernel hash code itself after it has
-	 * already taken the hash table lock. This works in conjunction
-	 * with pre-faulting of the kernel text.
-	 *
-	 * If the hash table bucket is full of kernel text entries, we'll
-	 * lockup here but that shouldn't happen
 	 */
 
-1:	lis	r4, (next_slot - PAGE_OFFSET)@ha	/* get next evict slot */
+	lis	r4, (next_slot - PAGE_OFFSET)@ha	/* get next evict slot */
 	lwz	r6, (next_slot - PAGE_OFFSET)@l(r4)
 	addi	r6,r6,HPTE_SIZE			/* search for candidate */
 	andi.	r6,r6,7*HPTE_SIZE
 	stw	r6,next_slot@l(r4)
 	add	r4,r3,r6
-	LDPTE	r0,HPTE_SIZE/2(r4)		/* get PTE second word */
-	clrrwi	r0,r0,12
-	lis	r6,etext@h
-	ori	r6,r6,etext@l			/* get etext */
-	tophys(r6,r6)
-	cmpl	cr0,r0,r6			/* compare and try again */
-	blt	1b
 
 #ifndef CONFIG_SMP
 	/* Store PTE in PTEG */
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index 5c60dcade90a..23f60e97196e 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -302,7 +302,7 @@ void __init setbat(int index, unsigned long virt, phys_addr_t phys,
 /*
  * Preload a translation in the hash table
  */
-void hash_preload(struct mm_struct *mm, unsigned long ea)
+static void hash_preload(struct mm_struct *mm, unsigned long ea)
 {
 	pmd_t *pmd;
 
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 1b6d39e9baed..0ad6d476d01d 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -91,8 +91,6 @@ void print_system_hash_info(void);
 
 #ifdef CONFIG_PPC32
 
-void hash_preload(struct mm_struct *mm, unsigned long ea);
-
 extern void mapin_ram(void);
 extern void setbat(int index, unsigned long virt, phys_addr_t phys,
 		   unsigned int size, pgprot_t prot);
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 079159e97bca..6e0083e7f008 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -112,10 +112,6 @@ static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
 		ktext = ((char *)v >= _stext && (char *)v < etext) ||
 			((char *)v >= _sinittext && (char *)v < _einittext);
 		map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
-#ifdef CONFIG_PPC_BOOK3S_32
-		if (ktext)
-			hash_preload(&init_mm, v);
-#endif
 		v += PAGE_SIZE;
 		p += PAGE_SIZE;
 	}
-- 
2.25.0

[PATCH v1 2/8] powerpc/32s: Don't hash_preload() kernel text

[Christophe Leroy]

We now always map kernel text with BATs. Neither need to preload
hash with kernel text addresses nor ensure they are never evicted.

This is more or less a revert of commit ee4f2ea48674 ("[POWERPC] Fix
32-bit mm operations when not using BATs")

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/book3s32/hash_low.S | 18 +-----------------
 arch/powerpc/mm/book3s32/mmu.c      |  2 +-
 arch/powerpc/mm/mmu_decl.h          |  2 --
 arch/powerpc/mm/pgtable_32.c        |  4 ----
 4 files changed, 2 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index b2c912e517b9..48415c857d80 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -411,30 +411,14 @@ END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
 	 * and we know there is a definite (although small) speed
 	 * advantage to putting the PTE in the primary PTEG, we always
 	 * put the PTE in the primary PTEG.
-	 *
-	 * In addition, we skip any slot that is mapping kernel text in
-	 * order to avoid a deadlock when not using BAT mappings if
-	 * trying to hash in the kernel hash code itself after it has
-	 * already taken the hash table lock. This works in conjunction
-	 * with pre-faulting of the kernel text.
-	 *
-	 * If the hash table bucket is full of kernel text entries, we'll
-	 * lockup here but that shouldn't happen
 	 */
 
-1:	lis	r4, (next_slot - PAGE_OFFSET)@ha	/* get next evict slot */
+	lis	r4, (next_slot - PAGE_OFFSET)@ha	/* get next evict slot */
 	lwz	r6, (next_slot - PAGE_OFFSET)@l(r4)
 	addi	r6,r6,HPTE_SIZE			/* search for candidate */
 	andi.	r6,r6,7*HPTE_SIZE
 	stw	r6,next_slot@l(r4)
 	add	r4,r3,r6
-	LDPTE	r0,HPTE_SIZE/2(r4)		/* get PTE second word */
-	clrrwi	r0,r0,12
-	lis	r6,etext@h
-	ori	r6,r6,etext@l			/* get etext */
-	tophys(r6,r6)
-	cmpl	cr0,r0,r6			/* compare and try again */
-	blt	1b
 
 #ifndef CONFIG_SMP
 	/* Store PTE in PTEG */
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index 5c60dcade90a..23f60e97196e 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -302,7 +302,7 @@ void __init setbat(int index, unsigned long virt, phys_addr_t phys,
 /*
  * Preload a translation in the hash table
  */
-void hash_preload(struct mm_struct *mm, unsigned long ea)
+static void hash_preload(struct mm_struct *mm, unsigned long ea)
 {
 	pmd_t *pmd;
 
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 1b6d39e9baed..0ad6d476d01d 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -91,8 +91,6 @@ void print_system_hash_info(void);
 
 #ifdef CONFIG_PPC32
 
-void hash_preload(struct mm_struct *mm, unsigned long ea);
-
 extern void mapin_ram(void);
 extern void setbat(int index, unsigned long virt, phys_addr_t phys,
 		   unsigned int size, pgprot_t prot);
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 079159e97bca..6e0083e7f008 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -112,10 +112,6 @@ static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
 		ktext = ((char *)v >= _stext && (char *)v < etext) ||
 			((char *)v >= _sinittext && (char *)v < _einittext);
 		map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
-#ifdef CONFIG_PPC_BOOK3S_32
-		if (ktext)
-			hash_preload(&init_mm, v);
-#endif
 		v += PAGE_SIZE;
 		p += PAGE_SIZE;
 	}
-- 
2.25.0

[PATCH v1 3/8] powerpc/32s: Fix an FTR_SECTION_ELSE

[Christophe Leroy]

An FTR_SECTION_ELSE is in the middle of
BEGIN_MMU_FTR_SECTION/ALT_MMU_FTR_SECTION_END_IFSET

Change it to MMU_FTR_SECTION_ELSE

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_book3s_32.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 27767f3e7ec1..236a95d163be 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -332,7 +332,7 @@ BEGIN_MMU_FTR_SECTION
 	rlwinm	r3, r5, 32 - 15, 21, 21		/* DSISR_STORE -> _PAGE_RW */
 	bl	hash_page
 	b	handle_page_fault_tramp_1
-FTR_SECTION_ELSE
+MMU_FTR_SECTION_ELSE
 	b	handle_page_fault_tramp_2
 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
 #endif	/* CONFIG_VMAP_STACK */
-- 
2.25.0

[PATCH v1 3/8] powerpc/32s: Fix an FTR_SECTION_ELSE

[Christophe Leroy]

An FTR_SECTION_ELSE is in the middle of
BEGIN_MMU_FTR_SECTION/ALT_MMU_FTR_SECTION_END_IFSET

Change it to MMU_FTR_SECTION_ELSE

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_book3s_32.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 27767f3e7ec1..236a95d163be 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -332,7 +332,7 @@ BEGIN_MMU_FTR_SECTION
 	rlwinm	r3, r5, 32 - 15, 21, 21		/* DSISR_STORE -> _PAGE_RW */
 	bl	hash_page
 	b	handle_page_fault_tramp_1
-FTR_SECTION_ELSE
+MMU_FTR_SECTION_ELSE
 	b	handle_page_fault_tramp_2
 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
 #endif	/* CONFIG_VMAP_STACK */
-- 
2.25.0

[PATCH v1 4/8] powerpc/32s: Don't use SPRN_SPRG_PGDIR in hash_page

[Christophe Leroy]

SPRN_SPRG_PGDIR is there mainly to speedup SW TLB miss handlers
for powerpc 603.

We need to free SPRN_SPRG2 to reduce the mess with CONFIG_VMAP_STACK.

In hash_page(), reading PGDIR from thread_struct will be in the noise
performance wise.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/book3s32/hash_low.S | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index 48415c857d80..aca353d1c5f4 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -65,13 +65,14 @@ _GLOBAL(hash_page)
 	/* Get PTE (linux-style) and check access */
 	lis	r0, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r4,r0
+	mfspr	r8,SPRN_SPRG_THREAD	/* current task's THREAD (phys) */
 	ori	r3,r3,_PAGE_USER|_PAGE_PRESENT /* test low addresses as user */
-	mfspr	r5, SPRN_SPRG_PGDIR	/* phys page-table root */
+	lwz	r5,PGDIR(r8)		/* virt page-table root */
 	blt+	112f			/* assume user more likely */
-	lis	r5, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
-	addi	r5 ,r5 ,(swapper_pg_dir - PAGE_OFFSET)@l	/* kernel page table */
+	lis	r5,swapper_pg_dir@ha	/* if kernel address, use */
+	addi	r5,r5,swapper_pg_dir@l	/* kernel page table */
 	rlwimi	r3,r9,32-12,29,29	/* MSR_PR -> _PAGE_USER */
-112:
+112:	tophys(r5, r5)
 #ifndef CONFIG_PTE_64BIT
 	rlwimi	r5,r4,12,20,29		/* insert top 10 bits of address */
 	lwz	r8,0(r5)		/* get pmd entry */
-- 
2.25.0

[PATCH v1 4/8] powerpc/32s: Don't use SPRN_SPRG_PGDIR in hash_page

[Christophe Leroy]

SPRN_SPRG_PGDIR is there mainly to speedup SW TLB miss handlers
for powerpc 603.

We need to free SPRN_SPRG2 to reduce the mess with CONFIG_VMAP_STACK.

In hash_page(), reading PGDIR from thread_struct will be in the noise
performance wise.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/book3s32/hash_low.S | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index 48415c857d80..aca353d1c5f4 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -65,13 +65,14 @@ _GLOBAL(hash_page)
 	/* Get PTE (linux-style) and check access */
 	lis	r0, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r4,r0
+	mfspr	r8,SPRN_SPRG_THREAD	/* current task's THREAD (phys) */
 	ori	r3,r3,_PAGE_USER|_PAGE_PRESENT /* test low addresses as user */
-	mfspr	r5, SPRN_SPRG_PGDIR	/* phys page-table root */
+	lwz	r5,PGDIR(r8)		/* virt page-table root */
 	blt+	112f			/* assume user more likely */
-	lis	r5, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
-	addi	r5 ,r5 ,(swapper_pg_dir - PAGE_OFFSET)@l	/* kernel page table */
+	lis	r5,swapper_pg_dir@ha	/* if kernel address, use */
+	addi	r5,r5,swapper_pg_dir@l	/* kernel page table */
 	rlwimi	r3,r9,32-12,29,29	/* MSR_PR -> _PAGE_USER */
-112:
+112:	tophys(r5, r5)
 #ifndef CONFIG_PTE_64BIT
 	rlwimi	r5,r4,12,20,29		/* insert top 10 bits of address */
 	lwz	r8,0(r5)		/* get pmd entry */
-- 
2.25.0

[PATCH v1 5/8] powerpc/603: Use SPRN_SDR1 to store the pgdir phys address

[Christophe Leroy]

On the 603, SDR1 is not used.

In order to free SPRN_SPRG2, use SPRN_SDR1 to store the pgdir
phys addr.

But only some bits of SDR1 can be used (0xffff01ff).
As the pgdir is 4k aligned, rotate it by 4 bits to the left.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/reg.h       |  1 -
 arch/powerpc/kernel/head_book3s_32.S | 31 +++++++++++++++++++++-------
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index f877a576b338..a37ce826f6f6 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1203,7 +1203,6 @@
 #ifdef CONFIG_PPC_BOOK3S_32
 #define SPRN_SPRG_SCRATCH0	SPRN_SPRG0
 #define SPRN_SPRG_SCRATCH1	SPRN_SPRG1
-#define SPRN_SPRG_PGDIR		SPRN_SPRG2
 #define SPRN_SPRG_603_LRU	SPRN_SPRG4
 #endif
 
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 236a95d163be..51eef7b82f9c 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -457,8 +457,9 @@ InstructionTLBMiss:
 	lis	r1, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r1,r3
 #endif
-	mfspr	r2, SPRN_SPRG_PGDIR
+	mfspr	r2, SPRN_SDR1
 	li	r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
+	rlwinm	r2, r2, 28, 0xfffff000
 #ifdef CONFIG_MODULES
 	bgt-	112f
 	lis	r2, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
@@ -519,8 +520,9 @@ DataLoadTLBMiss:
 	mfspr	r3,SPRN_DMISS
 	lis	r1, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r1,r3
-	mfspr	r2, SPRN_SPRG_PGDIR
+	mfspr	r2, SPRN_SDR1
 	li	r1, _PAGE_PRESENT | _PAGE_ACCESSED
+	rlwinm	r2, r2, 28, 0xfffff000
 	bgt-	112f
 	lis	r2, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
 	addi	r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l	/* kernel page table */
@@ -595,8 +597,9 @@ DataStoreTLBMiss:
 	mfspr	r3,SPRN_DMISS
 	lis	r1, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r1,r3
-	mfspr	r2, SPRN_SPRG_PGDIR
+	mfspr	r2, SPRN_SDR1
 	li	r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT | _PAGE_ACCESSED
+	rlwinm	r2, r2, 28, 0xfffff000
 	bgt-	112f
 	lis	r2, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
 	addi	r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l	/* kernel page table */
@@ -889,9 +892,12 @@ __secondary_start:
 	tophys(r4,r2)
 	addi	r4,r4,THREAD	/* phys address of our thread_struct */
 	mtspr	SPRN_SPRG_THREAD,r4
+BEGIN_MMU_FTR_SECTION
 	lis	r4, (swapper_pg_dir - PAGE_OFFSET)@h
 	ori	r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l
-	mtspr	SPRN_SPRG_PGDIR, r4
+	rlwinm	r4, r4, 4, 0xffff01ff
+	mtspr	SPRN_SDR1, r4
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
 
 	/* enable MMU and jump to start_secondary */
 	li	r4,MSR_KERNEL
@@ -931,11 +937,13 @@ load_up_mmu:
 	tlbia			/* Clear all TLB entries */
 	sync			/* wait for tlbia/tlbie to finish */
 	TLBSYNC			/* ... on all CPUs */
+BEGIN_MMU_FTR_SECTION
 	/* Load the SDR1 register (hash table base & size) */
 	lis	r6,_SDR1@ha
 	tophys(r6,r6)
 	lwz	r6,_SDR1@l(r6)
 	mtspr	SPRN_SDR1,r6
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
 
 /* Load the BAT registers with the values set up by MMU_init. */
 	lis	r3,BATS@ha
@@ -991,9 +999,12 @@ start_here:
 	tophys(r4,r2)
 	addi	r4,r4,THREAD	/* init task's THREAD */
 	mtspr	SPRN_SPRG_THREAD,r4
+BEGIN_MMU_FTR_SECTION
 	lis	r4, (swapper_pg_dir - PAGE_OFFSET)@h
 	ori	r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l
-	mtspr	SPRN_SPRG_PGDIR, r4
+	rlwinm	r4, r4, 4, 0xffff01ff
+	mtspr	SPRN_SDR1, r4
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
 
 	/* stack */
 	lis	r1,init_thread_union@ha
@@ -1073,16 +1084,22 @@ _ENTRY(switch_mmu_context)
 	li	r0,NUM_USER_SEGMENTS
 	mtctr	r0
 
-	lwz	r4, MM_PGD(r4)
 #ifdef CONFIG_BDI_SWITCH
 	/* Context switch the PTE pointer for the Abatron BDI2000.
 	 * The PGDIR is passed as second argument.
 	 */
+	lwz	r4, MM_PGD(r4)
 	lis	r5, abatron_pteptrs@ha
 	stw	r4, abatron_pteptrs@l + 0x4(r5)
+#endif
+BEGIN_MMU_FTR_SECTION
+#ifndef CONFIG_BDI_SWITCH
+	lwz	r4, MM_PGD(r4)
 #endif
 	tophys(r4, r4)
-	mtspr	SPRN_SPRG_PGDIR, r4
+	rlwinm	r4, r4, 4, 0xffff01ff
+	mtspr	SPRN_SDR1, r4
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
 	li	r4,0
 	isync
 3:
-- 
2.25.0

[PATCH v1 5/8] powerpc/603: Use SPRN_SDR1 to store the pgdir phys address

[Christophe Leroy]

On the 603, SDR1 is not used.

In order to free SPRN_SPRG2, use SPRN_SDR1 to store the pgdir
phys addr.

But only some bits of SDR1 can be used (0xffff01ff).
As the pgdir is 4k aligned, rotate it by 4 bits to the left.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/reg.h       |  1 -
 arch/powerpc/kernel/head_book3s_32.S | 31 +++++++++++++++++++++-------
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index f877a576b338..a37ce826f6f6 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1203,7 +1203,6 @@
 #ifdef CONFIG_PPC_BOOK3S_32
 #define SPRN_SPRG_SCRATCH0	SPRN_SPRG0
 #define SPRN_SPRG_SCRATCH1	SPRN_SPRG1
-#define SPRN_SPRG_PGDIR		SPRN_SPRG2
 #define SPRN_SPRG_603_LRU	SPRN_SPRG4
 #endif
 
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 236a95d163be..51eef7b82f9c 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -457,8 +457,9 @@ InstructionTLBMiss:
 	lis	r1, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r1,r3
 #endif
-	mfspr	r2, SPRN_SPRG_PGDIR
+	mfspr	r2, SPRN_SDR1
 	li	r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
+	rlwinm	r2, r2, 28, 0xfffff000
 #ifdef CONFIG_MODULES
 	bgt-	112f
 	lis	r2, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
@@ -519,8 +520,9 @@ DataLoadTLBMiss:
 	mfspr	r3,SPRN_DMISS
 	lis	r1, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r1,r3
-	mfspr	r2, SPRN_SPRG_PGDIR
+	mfspr	r2, SPRN_SDR1
 	li	r1, _PAGE_PRESENT | _PAGE_ACCESSED
+	rlwinm	r2, r2, 28, 0xfffff000
 	bgt-	112f
 	lis	r2, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
 	addi	r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l	/* kernel page table */
@@ -595,8 +597,9 @@ DataStoreTLBMiss:
 	mfspr	r3,SPRN_DMISS
 	lis	r1, TASK_SIZE@h		/* check if kernel address */
 	cmplw	0,r1,r3
-	mfspr	r2, SPRN_SPRG_PGDIR
+	mfspr	r2, SPRN_SDR1
 	li	r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT | _PAGE_ACCESSED
+	rlwinm	r2, r2, 28, 0xfffff000
 	bgt-	112f
 	lis	r2, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */
 	addi	r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l	/* kernel page table */
@@ -889,9 +892,12 @@ __secondary_start:
 	tophys(r4,r2)
 	addi	r4,r4,THREAD	/* phys address of our thread_struct */
 	mtspr	SPRN_SPRG_THREAD,r4
+BEGIN_MMU_FTR_SECTION
 	lis	r4, (swapper_pg_dir - PAGE_OFFSET)@h
 	ori	r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l
-	mtspr	SPRN_SPRG_PGDIR, r4
+	rlwinm	r4, r4, 4, 0xffff01ff
+	mtspr	SPRN_SDR1, r4
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
 
 	/* enable MMU and jump to start_secondary */
 	li	r4,MSR_KERNEL
@@ -931,11 +937,13 @@ load_up_mmu:
 	tlbia			/* Clear all TLB entries */
 	sync			/* wait for tlbia/tlbie to finish */
 	TLBSYNC			/* ... on all CPUs */
+BEGIN_MMU_FTR_SECTION
 	/* Load the SDR1 register (hash table base & size) */
 	lis	r6,_SDR1@ha
 	tophys(r6,r6)
 	lwz	r6,_SDR1@l(r6)
 	mtspr	SPRN_SDR1,r6
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
 
 /* Load the BAT registers with the values set up by MMU_init. */
 	lis	r3,BATS@ha
@@ -991,9 +999,12 @@ start_here:
 	tophys(r4,r2)
 	addi	r4,r4,THREAD	/* init task's THREAD */
 	mtspr	SPRN_SPRG_THREAD,r4
+BEGIN_MMU_FTR_SECTION
 	lis	r4, (swapper_pg_dir - PAGE_OFFSET)@h
 	ori	r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l
-	mtspr	SPRN_SPRG_PGDIR, r4
+	rlwinm	r4, r4, 4, 0xffff01ff
+	mtspr	SPRN_SDR1, r4
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
 
 	/* stack */
 	lis	r1,init_thread_union@ha
@@ -1073,16 +1084,22 @@ _ENTRY(switch_mmu_context)
 	li	r0,NUM_USER_SEGMENTS
 	mtctr	r0
 
-	lwz	r4, MM_PGD(r4)
 #ifdef CONFIG_BDI_SWITCH
 	/* Context switch the PTE pointer for the Abatron BDI2000.
 	 * The PGDIR is passed as second argument.
 	 */
+	lwz	r4, MM_PGD(r4)
 	lis	r5, abatron_pteptrs@ha
 	stw	r4, abatron_pteptrs@l + 0x4(r5)
+#endif
+BEGIN_MMU_FTR_SECTION
+#ifndef CONFIG_BDI_SWITCH
+	lwz	r4, MM_PGD(r4)
 #endif
 	tophys(r4, r4)
-	mtspr	SPRN_SPRG_PGDIR, r4
+	rlwinm	r4, r4, 4, 0xffff01ff
+	mtspr	SPRN_SDR1, r4
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
 	li	r4,0
 	isync
 3:
-- 
2.25.0

[PATCH v1 6/8] powerpc/32: Simplify EXCEPTION_PROLOG_1 macro

[Christophe Leroy]

Make code more readable with a clear CONFIG_VMAP_STACK
section and a clear non CONFIG_VMAP_STACK section.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 7c767765071d..5e3393122d29 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -46,18 +46,16 @@
 	mfspr	r1,SPRN_SPRG_THREAD
 	lwz	r1,TASK_STACK-THREAD(r1)
 	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
+1:
+	mtcrf	0x7f, r1
+	bt	32 - THREAD_ALIGN_SHIFT, stack_overflow
 #else
 	subi	r11, r1, INT_FRAME_SIZE		/* use r1 if kernel */
 	beq	1f
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,TASK_STACK-THREAD(r11)
 	addi	r11, r11, THREAD_SIZE - INT_FRAME_SIZE
-#endif
-1:
-	tophys_novmstack r11, r11
-#ifdef CONFIG_VMAP_STACK
-	mtcrf	0x7f, r1
-	bt	32 - THREAD_ALIGN_SHIFT, stack_overflow
+1:	tophys(r11, r11)
 #endif
 .endm
 
-- 
2.25.0

[PATCH v1 6/8] powerpc/32: Simplify EXCEPTION_PROLOG_1 macro

[Christophe Leroy]

Make code more readable with a clear CONFIG_VMAP_STACK
section and a clear non CONFIG_VMAP_STACK section.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 7c767765071d..5e3393122d29 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -46,18 +46,16 @@
 	mfspr	r1,SPRN_SPRG_THREAD
 	lwz	r1,TASK_STACK-THREAD(r1)
 	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
+1:
+	mtcrf	0x7f, r1
+	bt	32 - THREAD_ALIGN_SHIFT, stack_overflow
 #else
 	subi	r11, r1, INT_FRAME_SIZE		/* use r1 if kernel */
 	beq	1f
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,TASK_STACK-THREAD(r11)
 	addi	r11, r11, THREAD_SIZE - INT_FRAME_SIZE
-#endif
-1:
-	tophys_novmstack r11, r11
-#ifdef CONFIG_VMAP_STACK
-	mtcrf	0x7f, r1
-	bt	32 - THREAD_ALIGN_SHIFT, stack_overflow
+1:	tophys(r11, r11)
 #endif
 .endm
 
-- 
2.25.0

[PATCH v1 7/8] powerpc/32s: Use SPRN_SPRG_SCRATCH2 in DSI prolog

[Christophe Leroy]

Use SPRN_SPRG_SCRATCH2 as an alternative scratch register in
the early part of DSI prolog in order to avoid clobbering
SPRN_SPRG_SCRATCH0/1 used by other prologs.

The 603 doesn't like a jump from DataLoadTLBMiss to the 10 nops
that are now in the beginning of DSI exception as a result of
the feature section. To workaround this, add a jump as alternative.
It also avoids fetching 10 nops for nothing.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/reg.h       |  1 +
 arch/powerpc/kernel/head_book3s_32.S | 24 ++++++++----------------
 2 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index a37ce826f6f6..acd334ee3936 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1203,6 +1203,7 @@
 #ifdef CONFIG_PPC_BOOK3S_32
 #define SPRN_SPRG_SCRATCH0	SPRN_SPRG0
 #define SPRN_SPRG_SCRATCH1	SPRN_SPRG1
+#define SPRN_SPRG_SCRATCH2	SPRN_SPRG2
 #define SPRN_SPRG_603_LRU	SPRN_SPRG4
 #endif
 
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 51eef7b82f9c..22d670263222 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -288,9 +288,9 @@ MachineCheck:
 	DO_KVM  0x300
 DataAccess:
 #ifdef CONFIG_VMAP_STACK
-	mtspr	SPRN_SPRG_SCRATCH0,r10
-	mfspr	r10, SPRN_SPRG_THREAD
 BEGIN_MMU_FTR_SECTION
+	mtspr	SPRN_SPRG_SCRATCH2,r10
+	mfspr	r10, SPRN_SPRG_THREAD
 	stw	r11, THR11(r10)
 	mfspr	r10, SPRN_DSISR
 	mfcr	r11
@@ -304,19 +304,11 @@ BEGIN_MMU_FTR_SECTION
 .Lhash_page_dsi_cont:
 	mtcr	r11
 	lwz	r11, THR11(r10)
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
-	mtspr	SPRN_SPRG_SCRATCH1,r11
-	mfspr	r11, SPRN_DAR
-	stw	r11, DAR(r10)
-	mfspr	r11, SPRN_DSISR
-	stw	r11, DSISR(r10)
-	mfspr	r11, SPRN_SRR0
-	stw	r11, SRR0(r10)
-	mfspr	r11, SPRN_SRR1		/* check whether user or kernel */
-	stw	r11, SRR1(r10)
-	mfcr	r10
-	andi.	r11, r11, MSR_PR
-
+	mfspr	r10, SPRN_SPRG_SCRATCH2
+MMU_FTR_SECTION_ELSE
+	b	1f
+ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
+1:	EXCEPTION_PROLOG_0 handle_dar_dsisr=1
 	EXCEPTION_PROLOG_1
 	b	handle_page_fault_tramp_1
 #else	/* CONFIG_VMAP_STACK */
@@ -760,7 +752,7 @@ fast_hash_page_return:
 	/* DSI */
 	mtcr	r11
 	lwz	r11, THR11(r10)
-	mfspr	r10, SPRN_SPRG_SCRATCH0
+	mfspr	r10, SPRN_SPRG_SCRATCH2
 	RFI
 
 1:	/* ISI */
-- 
2.25.0

[PATCH v1 7/8] powerpc/32s: Use SPRN_SPRG_SCRATCH2 in DSI prolog

[Christophe Leroy]

Use SPRN_SPRG_SCRATCH2 as an alternative scratch register in
the early part of DSI prolog in order to avoid clobbering
SPRN_SPRG_SCRATCH0/1 used by other prologs.

The 603 doesn't like a jump from DataLoadTLBMiss to the 10 nops
that are now in the beginning of DSI exception as a result of
the feature section. To workaround this, add a jump as alternative.
It also avoids fetching 10 nops for nothing.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/reg.h       |  1 +
 arch/powerpc/kernel/head_book3s_32.S | 24 ++++++++----------------
 2 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index a37ce826f6f6..acd334ee3936 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1203,6 +1203,7 @@
 #ifdef CONFIG_PPC_BOOK3S_32
 #define SPRN_SPRG_SCRATCH0	SPRN_SPRG0
 #define SPRN_SPRG_SCRATCH1	SPRN_SPRG1
+#define SPRN_SPRG_SCRATCH2	SPRN_SPRG2
 #define SPRN_SPRG_603_LRU	SPRN_SPRG4
 #endif
 
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 51eef7b82f9c..22d670263222 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -288,9 +288,9 @@ MachineCheck:
 	DO_KVM  0x300
 DataAccess:
 #ifdef CONFIG_VMAP_STACK
-	mtspr	SPRN_SPRG_SCRATCH0,r10
-	mfspr	r10, SPRN_SPRG_THREAD
 BEGIN_MMU_FTR_SECTION
+	mtspr	SPRN_SPRG_SCRATCH2,r10
+	mfspr	r10, SPRN_SPRG_THREAD
 	stw	r11, THR11(r10)
 	mfspr	r10, SPRN_DSISR
 	mfcr	r11
@@ -304,19 +304,11 @@ BEGIN_MMU_FTR_SECTION
 .Lhash_page_dsi_cont:
 	mtcr	r11
 	lwz	r11, THR11(r10)
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
-	mtspr	SPRN_SPRG_SCRATCH1,r11
-	mfspr	r11, SPRN_DAR
-	stw	r11, DAR(r10)
-	mfspr	r11, SPRN_DSISR
-	stw	r11, DSISR(r10)
-	mfspr	r11, SPRN_SRR0
-	stw	r11, SRR0(r10)
-	mfspr	r11, SPRN_SRR1		/* check whether user or kernel */
-	stw	r11, SRR1(r10)
-	mfcr	r10
-	andi.	r11, r11, MSR_PR
-
+	mfspr	r10, SPRN_SPRG_SCRATCH2
+MMU_FTR_SECTION_ELSE
+	b	1f
+ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
+1:	EXCEPTION_PROLOG_0 handle_dar_dsisr=1
 	EXCEPTION_PROLOG_1
 	b	handle_page_fault_tramp_1
 #else	/* CONFIG_VMAP_STACK */
@@ -760,7 +752,7 @@ fast_hash_page_return:
 	/* DSI */
 	mtcr	r11
 	lwz	r11, THR11(r10)
-	mfspr	r10, SPRN_SPRG_SCRATCH0
+	mfspr	r10, SPRN_SPRG_SCRATCH2
 	RFI
 
 1:	/* ISI */
-- 
2.25.0

[PATCH v1 8/8] powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs

[Christophe Leroy]

Use SPRN_SPRG_SCRATCH2 as a third scratch register in
exception prologs in order to simplify them and avoid
data going back and forth from/to CR.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 5e3393122d29..a1ee1e12241e 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -40,7 +40,7 @@
 
 .macro EXCEPTION_PROLOG_1 for_rtas=0
 #ifdef CONFIG_VMAP_STACK
-	mr	r11, r1
+	mtspr	SPRN_SPRG_SCRATCH2,r1
 	subi	r1, r1, INT_FRAME_SIZE		/* use r1 if kernel */
 	beq	1f
 	mfspr	r1,SPRN_SPRG_THREAD
@@ -61,15 +61,10 @@
 
 .macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
 #ifdef CONFIG_VMAP_STACK
-	mtcr	r10
-	li	r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
-	mtmsr	r10
+	li	r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
+	mtmsr	r11
 	isync
-#else
-	stw	r10,_CCR(r11)		/* save registers */
-#endif
-	mfspr	r10, SPRN_SPRG_SCRATCH0
-#ifdef CONFIG_VMAP_STACK
+	mfspr	r11, SPRN_SPRG_SCRATCH2
 	stw	r11,GPR1(r1)
 	stw	r11,0(r1)
 	mr	r11, r1
@@ -78,14 +73,12 @@
 	stw	r1,0(r11)
 	tovirt(r1, r11)		/* set new kernel sp */
 #endif
+	stw	r10,_CCR(r11)		/* save registers */
 	stw	r12,GPR12(r11)
 	stw	r9,GPR9(r11)
-	stw	r10,GPR10(r11)
-#ifdef CONFIG_VMAP_STACK
-	mfcr	r10
-	stw	r10, _CCR(r11)
-#endif
+	mfspr	r10,SPRN_SPRG_SCRATCH0
 	mfspr	r12,SPRN_SPRG_SCRATCH1
+	stw	r10,GPR10(r11)
 	stw	r12,GPR11(r11)
 	mflr	r10
 	stw	r10,_LINK(r11)
@@ -99,7 +92,6 @@
 	stw	r10, _DSISR(r11)
 	.endif
 	lwz	r9, SRR1(r12)
-	andi.	r10, r9, MSR_PR
 	lwz	r12, SRR0(r12)
 #else
 	mfspr	r12,SPRN_SRR0
-- 
2.25.0

[PATCH v1 8/8] powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs

[Christophe Leroy]

Use SPRN_SPRG_SCRATCH2 as a third scratch register in
exception prologs in order to simplify them and avoid
data going back and forth from/to CR.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 5e3393122d29..a1ee1e12241e 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -40,7 +40,7 @@
 
 .macro EXCEPTION_PROLOG_1 for_rtas=0
 #ifdef CONFIG_VMAP_STACK
-	mr	r11, r1
+	mtspr	SPRN_SPRG_SCRATCH2,r1
 	subi	r1, r1, INT_FRAME_SIZE		/* use r1 if kernel */
 	beq	1f
 	mfspr	r1,SPRN_SPRG_THREAD
@@ -61,15 +61,10 @@
 
 .macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
 #ifdef CONFIG_VMAP_STACK
-	mtcr	r10
-	li	r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
-	mtmsr	r10
+	li	r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
+	mtmsr	r11
 	isync
-#else
-	stw	r10,_CCR(r11)		/* save registers */
-#endif
-	mfspr	r10, SPRN_SPRG_SCRATCH0
-#ifdef CONFIG_VMAP_STACK
+	mfspr	r11, SPRN_SPRG_SCRATCH2
 	stw	r11,GPR1(r1)
 	stw	r11,0(r1)
 	mr	r11, r1
@@ -78,14 +73,12 @@
 	stw	r1,0(r11)
 	tovirt(r1, r11)		/* set new kernel sp */
 #endif
+	stw	r10,_CCR(r11)		/* save registers */
 	stw	r12,GPR12(r11)
 	stw	r9,GPR9(r11)
-	stw	r10,GPR10(r11)
-#ifdef CONFIG_VMAP_STACK
-	mfcr	r10
-	stw	r10, _CCR(r11)
-#endif
+	mfspr	r10,SPRN_SPRG_SCRATCH0
 	mfspr	r12,SPRN_SPRG_SCRATCH1
+	stw	r10,GPR10(r11)
 	stw	r12,GPR11(r11)
 	mflr	r10
 	stw	r10,_LINK(r11)
@@ -99,7 +92,6 @@
 	stw	r10, _DSISR(r11)
 	.endif
 	lwz	r9, SRR1(r12)
-	andi.	r10, r9, MSR_PR
 	lwz	r12, SRR0(r12)
 #else
 	mfspr	r12,SPRN_SRR0
-- 
2.25.0

Re: [PATCH v1 1/8] powerpc/32s: Always map kernel text and rodata with BATs

[Michael Ellerman]

On Wed, 25 Nov 2020 07:10:46 +0000 (UTC), Christophe Leroy wrote:
> Since commit 2b279c0348af ("powerpc/32s: Allow mapping with BATs with
> DEBUG_PAGEALLOC"), there is no real situation where mapping without
> BATs is required.
> 
> In order to simplify memory handling, always map kernel text
> and rodata with BATs even when "nobats" kernel parameter is set.
> 
> [...]

Applied to powerpc/next.

[1/8] powerpc/32s: Always map kernel text and rodata with BATs
      https://git.kernel.org/powerpc/c/035b19a15a98907916a42a6b1d025877c42f10ad
[2/8] powerpc/32s: Don't hash_preload() kernel text
      https://git.kernel.org/powerpc/c/79d1befe054ad4adb277fbd2d2756b1394eaf24e
[3/8] powerpc/32s: Fix an FTR_SECTION_ELSE
      https://git.kernel.org/powerpc/c/7b107a71e732c298d684ee1bafd82f1a2be58d5e
[4/8] powerpc/32s: Don't use SPRN_SPRG_PGDIR in hash_page
      https://git.kernel.org/powerpc/c/03d701c2d9b0091cf8e96cb49ab7d2a6a9f19937
[5/8] powerpc/603: Use SPRN_SDR1 to store the pgdir phys address
      https://git.kernel.org/powerpc/c/c4a22611bf6ced73d86bdfc0604d7db8982a24a4
[6/8] powerpc/32: Simplify EXCEPTION_PROLOG_1 macro
      https://git.kernel.org/powerpc/c/6285f9cff570bfd07b542840912c1d01bd5428e0
[7/8] powerpc/32s: Use SPRN_SPRG_SCRATCH2 in DSI prolog
      https://git.kernel.org/powerpc/c/de1cd0790697e67b728de43e8657bb52f528bfb9
[8/8] powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs
      https://git.kernel.org/powerpc/c/d2e006036082e2dc394c5ec86c5bb88cc27c0749

cheers

Re: [PATCH v1 1/8] powerpc/32s: Always map kernel text and rodata with BATs

[Michael Ellerman]

On Wed, 25 Nov 2020 07:10:46 +0000 (UTC), Christophe Leroy wrote:
> Since commit 2b279c0348af ("powerpc/32s: Allow mapping with BATs with
> DEBUG_PAGEALLOC"), there is no real situation where mapping without
> BATs is required.
> 
> In order to simplify memory handling, always map kernel text
> and rodata with BATs even when "nobats" kernel parameter is set.
> 
> [...]

Applied to powerpc/next.

[1/8] powerpc/32s: Always map kernel text and rodata with BATs
      https://git.kernel.org/powerpc/c/035b19a15a98907916a42a6b1d025877c42f10ad
[2/8] powerpc/32s: Don't hash_preload() kernel text
      https://git.kernel.org/powerpc/c/79d1befe054ad4adb277fbd2d2756b1394eaf24e
[3/8] powerpc/32s: Fix an FTR_SECTION_ELSE
      https://git.kernel.org/powerpc/c/7b107a71e732c298d684ee1bafd82f1a2be58d5e
[4/8] powerpc/32s: Don't use SPRN_SPRG_PGDIR in hash_page
      https://git.kernel.org/powerpc/c/03d701c2d9b0091cf8e96cb49ab7d2a6a9f19937
[5/8] powerpc/603: Use SPRN_SDR1 to store the pgdir phys address
      https://git.kernel.org/powerpc/c/c4a22611bf6ced73d86bdfc0604d7db8982a24a4
[6/8] powerpc/32: Simplify EXCEPTION_PROLOG_1 macro
      https://git.kernel.org/powerpc/c/6285f9cff570bfd07b542840912c1d01bd5428e0
[7/8] powerpc/32s: Use SPRN_SPRG_SCRATCH2 in DSI prolog
      https://git.kernel.org/powerpc/c/de1cd0790697e67b728de43e8657bb52f528bfb9
[8/8] powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs
      https://git.kernel.org/powerpc/c/d2e006036082e2dc394c5ec86c5bb88cc27c0749

cheers