linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v9 1/4] powerpc: Introduce local (non-broadcast) forms of tlb invalidates
@ 2008-09-19  0:09 Kumar Gala
  2008-09-19  0:09 ` [PATCH v9 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support Kumar Gala
  0 siblings, 1 reply; 5+ messages in thread
From: Kumar Gala @ 2008-09-19  0:09 UTC (permalink / raw)
  To: linuxppc-dev

Introduced a new set of low level tlb invalidate functions that do not
broadcast invalidates on the bus:

_tlbil_all - invalidate all
_tlbil_pid - invalidate based on process id (or mm context)
_tlbil_va  - invalidate based on virtual address (ea + pid)

On non-SMP configs _tlbil_all should be functionally equivalent to _tlbia and
_tlbil_va should be functionally equivalent to _tlbie.

The intent of this change is to handle SMP based invalidates via IPIs instead
of broadcasts as the mechanism scales better for larger number of cores.

On e500 (fsl-booke mmu) based cores move to using MMUCSR for invalidate alls
and tlbsx/tlbwe for invalidate virtual address.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
 arch/powerpc/include/asm/reg_booke.h |    7 ++++
 arch/powerpc/include/asm/tlbflush.h  |   13 +++++---
 arch/powerpc/kernel/misc_32.S        |   54 ++++++++++++++++++++++++++++++++++
 arch/powerpc/kernel/ppc_ksyms.c      |    3 ++
 4 files changed, 72 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/reg_booke.h b/arch/powerpc/include/asm/reg_booke.h
index be980f4..6745376 100644
--- a/arch/powerpc/include/asm/reg_booke.h
+++ b/arch/powerpc/include/asm/reg_booke.h
@@ -109,6 +109,7 @@
 #define SPRN_EVPR	0x3D6	/* Exception Vector Prefix Register */
 #define SPRN_L1CSR0	0x3F2	/* L1 Cache Control and Status Register 0 */
 #define SPRN_L1CSR1	0x3F3	/* L1 Cache Control and Status Register 1 */
+#define SPRN_MMUCSR0	0x3F4	/* MMU Control and Status Register 0 */
 #define SPRN_PIT	0x3DB	/* Programmable Interval Timer */
 #define SPRN_BUCSR	0x3F5	/* Branch Unit Control and Status */
 #define SPRN_L2CSR0	0x3F9	/* L2 Data Cache Control and Status Register 0 */
@@ -410,6 +411,12 @@
 #define L2CSR0_L2LOA	0x00000080	/* L2 Cache Lock Overflow Allocate */
 #define L2CSR0_L2LO	0x00000020	/* L2 Cache Lock Overflow */
 
+/* Bit definitions for MMUCSR0 */
+#define MMUCSR0_TLB1FI	0x00000002	/* TLB1 Flash invalidate */
+#define MMUCSR0_TLB0FI	0x00000004	/* TLB0 Flash invalidate */
+#define MMUCSR0_TLB2FI	0x00000040	/* TLB2 Flash invalidate */
+#define MMUCSR0_TLB3FI	0x00000020	/* TLB3 Flash invalidate */
+
 /* Bit definitions for SGR. */
 #define SGR_NORMAL	0		/* Speculative fetching allowed. */
 #define SGR_GUARDED	1		/* Speculative fetching disallowed. */
diff --git a/arch/powerpc/include/asm/tlbflush.h b/arch/powerpc/include/asm/tlbflush.h
index 361cd5c..a2c6bfd 100644
--- a/arch/powerpc/include/asm/tlbflush.h
+++ b/arch/powerpc/include/asm/tlbflush.h
@@ -29,6 +29,9 @@
 #include <linux/mm.h>
 
 extern void _tlbie(unsigned long address, unsigned int pid);
+extern void _tlbil_all(void);
+extern void _tlbil_pid(unsigned int pid);
+extern void _tlbil_va(unsigned long address, unsigned int pid);
 
 #if defined(CONFIG_40x) || defined(CONFIG_8xx)
 #define _tlbia()	asm volatile ("tlbia; sync" : : : "memory")
@@ -38,31 +41,31 @@ extern void _tlbia(void);
 
 static inline void flush_tlb_mm(struct mm_struct *mm)
 {
-	_tlbia();
+	_tlbil_pid(mm->context.id);
 }
 
 static inline void flush_tlb_page(struct vm_area_struct *vma,
 				  unsigned long vmaddr)
 {
-	_tlbie(vmaddr, vma ? vma->vm_mm->context.id : 0);
+	_tlbil_va(vmaddr, vma ? vma->vm_mm->context.id : 0);
 }
 
 static inline void flush_tlb_page_nohash(struct vm_area_struct *vma,
 					 unsigned long vmaddr)
 {
-	_tlbie(vmaddr, vma ? vma->vm_mm->context.id : 0);
+	flush_tlb_page(vma, vmaddr);
 }
 
 static inline void flush_tlb_range(struct vm_area_struct *vma,
 				   unsigned long start, unsigned long end)
 {
-	_tlbia();
+	_tlbil_pid(vma->vm_mm->context.id);
 }
 
 static inline void flush_tlb_kernel_range(unsigned long start,
 					  unsigned long end)
 {
-	_tlbia();
+	_tlbil_pid(0);
 }
 
 #elif defined(CONFIG_PPC32)
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 7a6dfbc..e9c8ab6 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -274,6 +274,10 @@ _GLOBAL(real_writeb)
 /*
  * Flush MMU TLB
  */
+#ifndef CONFIG_FSL_BOOKE
+_GLOBAL(_tlbil_all)
+_GLOBAL(_tlbil_pid)
+#endif
 _GLOBAL(_tlbia)
 #if defined(CONFIG_40x)
 	sync			/* Flush to memory before changing mapping */
@@ -344,6 +348,9 @@ _GLOBAL(_tlbia)
 /*
  * Flush MMU TLB for a particular address
  */
+#ifndef CONFIG_FSL_BOOKE
+_GLOBAL(_tlbil_va)
+#endif
 _GLOBAL(_tlbie)
 #if defined(CONFIG_40x)
 	/* We run the search with interrupts disabled because we have to change
@@ -436,6 +443,53 @@ _GLOBAL(_tlbie)
 #endif /* ! CONFIG_40x */
 	blr
 
+#if defined(CONFIG_FSL_BOOKE)
+/*
+ * Flush MMU TLB, but only on the local processor (no broadcast)
+ */
+_GLOBAL(_tlbil_all)
+#define MMUCSR0_TLBFI	(MMUCSR0_TLB0FI | MMUCSR0_TLB1FI | \
+			 MMUCSR0_TLB2FI | MMUCSR0_TLB3FI)
+	li	r3,(MMUCSR0_TLBFI)@l
+	mtspr	SPRN_MMUCSR0, r3
+1:
+	mfspr	r3,SPRN_MMUCSR0
+	andi.	r3,r3,MMUCSR0_TLBFI@l
+	bne	1b
+	blr
+
+/*
+ * Flush MMU TLB for a particular process id, but only on the local processor
+ * (no broadcast)
+ */
+_GLOBAL(_tlbil_pid)
+/* we currently do an invalidate all since we don't have per pid invalidate */
+	li	r3,(MMUCSR0_TLBFI)@l
+	mtspr	SPRN_MMUCSR0, r3
+1:
+	mfspr	r3,SPRN_MMUCSR0
+	andi.	r3,r3,MMUCSR0_TLBFI@l
+	bne	1b
+	blr
+
+/*
+ * Flush MMU TLB for a particular address, but only on the local processor
+ * (no broadcast)
+ */
+_GLOBAL(_tlbil_va)
+	slwi	r4,r4,16
+	mtspr	SPRN_MAS6,r4		/* assume AS=0 for now */
+	tlbsx	0,r3
+	mfspr	r4,SPRN_MAS1		/* check valid */
+	andis.	r3,r4,MAS1_VALID@h
+	beqlr
+	rlwinm	r4,r4,0,1,31
+	mtspr	SPRN_MAS1,r4
+	tlbwe
+	blr
+#endif /* CONFIG_FSL_BOOKE */
+
+
 /*
  * Flush instruction cache.
  * This is a no-op on the 601.
diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c
index e1ea4fe..8edc235 100644
--- a/arch/powerpc/kernel/ppc_ksyms.c
+++ b/arch/powerpc/kernel/ppc_ksyms.c
@@ -119,6 +119,9 @@ EXPORT_SYMBOL(flush_instruction_cache);
 EXPORT_SYMBOL(flush_tlb_kernel_range);
 EXPORT_SYMBOL(flush_tlb_page);
 EXPORT_SYMBOL(_tlbie);
+#if defined(CONFIG_4xx) || defined(CONFIG_8xx) || defined(CONFIG_FSL_BOOKE)
+EXPORT_SYMBOL(_tlbil_va);
+#endif
 #endif
 EXPORT_SYMBOL(__flush_icache_range);
 EXPORT_SYMBOL(flush_dcache_range);
-- 
1.5.5.1

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH v9 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support
  2008-09-19  0:09 [PATCH v9 1/4] powerpc: Introduce local (non-broadcast) forms of tlb invalidates Kumar Gala
@ 2008-09-19  0:09 ` Kumar Gala
  2008-09-19  0:09   ` [PATCH v9 3/4] powerpc/fsl-booke: Fixup 64-bit PTE reading " Kumar Gala
  2008-09-23 16:13   ` [PATCH v9 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support Becky Bruce
  0 siblings, 2 replies; 5+ messages in thread
From: Kumar Gala @ 2008-09-19  0:09 UTC (permalink / raw)
  To: linuxppc-dev

There are some minor issues with support 64-bit PTEs on a 32-bit processor
when dealing with SMP.

* We need to order the stores in set_pte_at to make sure the flag word
  is set second.
* Change pte_clear to use pte_update so only the flag word is cleared
* Added a WARN_ON to set_pte_at to ensure the pte isn't present for
  the 64-bit pte/SMP case (to ensure our assumption of this fact).

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
make it actually build.  I'm searching for a large brown paper bag.

- k

 arch/powerpc/include/asm/highmem.h       |    2 +-
 arch/powerpc/include/asm/pgtable-ppc32.h |   25 ++++++++++++++++++++-----
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index 5d99b64..91c5895 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -84,7 +84,7 @@ static inline void *kmap_atomic_prot(struct page *page, enum km_type type, pgpro
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(kmap_pte-idx)));
 #endif
-	set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
+	__set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
 	flush_tlb_page(NULL, vaddr);
 
 	return (void*) vaddr;
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index 6fe39e3..1b11955 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h
@@ -517,7 +517,8 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
 
 #define pte_none(pte)		((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
 #define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
-#define pte_clear(mm,addr,ptep)	do { set_pte_at((mm), (addr), (ptep), __pte(0)); } while (0)
+#define pte_clear(mm, addr, ptep) \
+	do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)
 
 #define pmd_none(pmd)		(!pmd_val(pmd))
 #define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
@@ -612,9 +613,6 @@ static inline unsigned long pte_update(pte_t *p,
 	return old;
 }
 #else /* CONFIG_PTE_64BIT */
-/* TODO: Change that to only modify the low word and move set_pte_at()
- * out of line
- */
 static inline unsigned long long pte_update(pte_t *p,
 					    unsigned long clr,
 					    unsigned long set)
@@ -652,16 +650,33 @@ static inline unsigned long long pte_update(pte_t *p,
  * On machines which use an MMU hash table we avoid changing the
  * _PAGE_HASHPTE bit.
  */
-static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+
+static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 			      pte_t *ptep, pte_t pte)
 {
 #if _PAGE_HASHPTE != 0
 	pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte) & ~_PAGE_HASHPTE);
+#elif defined(CONFIG_PTE_64BIT) && defined(CONFIG_SMP)
+	__asm__ __volatile__("\
+		stw%U0%X0 %2,%0\n\
+		eieio\n\
+		stw%U0%X0 %L2,%1"
+	: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
+	: "r" (pte) : "memory");
 #else
 	*ptep = pte;
 #endif
 }
 
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, pte_t pte)
+{
+#if defined(CONFIG_PTE_64BIT) && defined(CONFIG_SMP)
+	WARN_ON(pte_present(*ptep));
+#endif
+	__set_pte_at(mm, addr, ptep, pte);
+}
+
 /*
  * 2.6 calls this without flushing the TLB entry; this is wrong
  * for our hash-based implementation, we fix that up here.
-- 
1.5.5.1

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH v9 3/4] powerpc/fsl-booke: Fixup 64-bit PTE reading for SMP support
  2008-09-19  0:09 ` [PATCH v9 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support Kumar Gala
@ 2008-09-19  0:09   ` Kumar Gala
  2008-09-19  0:09     ` [PATCH v9 4/4] powerpc/mm: Implement _PAGE_SPECIAL & pte_special() for 32-bit Kumar Gala
  2008-09-23 16:13   ` [PATCH v9 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support Becky Bruce
  1 sibling, 1 reply; 5+ messages in thread
From: Kumar Gala @ 2008-09-19  0:09 UTC (permalink / raw)
  To: linuxppc-dev

We need to create a false data dependency to ensure the loads of
the pte are done in the right order.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
 arch/powerpc/kernel/head_fsl_booke.S |   26 +++++++++++++++++++++-----
 1 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 3cb52fa..377e0c1 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -579,13 +579,19 @@ interrupt_base:
 
 	FIND_PTE
 	andc.	r13,r13,r11		/* Check permission */
-	bne	2f			/* Bail if permission mismach */
 
 #ifdef CONFIG_PTE_64BIT
-	lwz	r13, 0(r12)
+#ifdef CONFIG_SMP
+	subf	r10,r11,r12		/* create false data dep */
+	lwzx	r13,r11,r10		/* Get upper pte bits */
+#else
+	lwz	r13,0(r12)		/* Get upper pte bits */
+#endif
 #endif
 
-	 /* Jump to common tlb load */
+	bne	2f			/* Bail if permission/valid mismach */
+
+	/* Jump to common tlb load */
 	b	finish_tlb_load
 2:
 	/* The bailout.  Restore registers to pre-exception conditions
@@ -640,10 +646,20 @@ interrupt_base:
 
 	FIND_PTE
 	andc.	r13,r13,r11		/* Check permission */
+
+#ifdef CONFIG_PTE_64BIT
+#ifdef CONFIG_SMP
+	subf	r10,r11,r12		/* create false data dep */
+	lwzx	r13,r11,r10		/* Get upper pte bits */
+#else
+	lwz	r13,0(r12)		/* Get upper pte bits */
+#endif
+#endif
+
 	bne	2f			/* Bail if permission mismach */
 
 #ifdef CONFIG_PTE_64BIT
-	lwz	r13, 0(r12)
+	lwz	r13,0(r12)
 #endif
 
 	/* Jump to common TLB load point */
@@ -702,7 +718,7 @@ interrupt_base:
 /*
  * Both the instruction and data TLB miss get to this
  * point to load the TLB.
- *	r10 - EA of fault
+ *	r10 - available to use
  *	r11 - TLB (info from Linux PTE)
  *	r12 - available to use
  *	r13 - upper bits of PTE (if PTE_64BIT) or available to use
-- 
1.5.5.1

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH v9 4/4] powerpc/mm: Implement _PAGE_SPECIAL & pte_special() for 32-bit
  2008-09-19  0:09   ` [PATCH v9 3/4] powerpc/fsl-booke: Fixup 64-bit PTE reading " Kumar Gala
@ 2008-09-19  0:09     ` Kumar Gala
  0 siblings, 0 replies; 5+ messages in thread
From: Kumar Gala @ 2008-09-19  0:09 UTC (permalink / raw)
  To: linuxppc-dev

Implement _PAGE_SPECIAL and pte_special() for 32-bit powerpc. This bit will
be used by the fast get_user_pages() to differenciate PTEs that correspond
to a valid struct page from special mappings that don't such as IO mappings
obtained via io_remap_pfn_ranges().

We currently only implement this on sub-arch that support SMP or will so
in the future (6xx, 44x, FSL-BookE) and not (8xx, 40x).

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/include/asm/pgtable-ppc32.h |   15 +++++++++++++--
 1 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index 1b11955..c2e58b4 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h
@@ -261,6 +261,7 @@ extern int icache_44x_need_flush;
 #define _PAGE_HWEXEC	0x00000004		/* H: Execute permission */
 #define _PAGE_ACCESSED	0x00000008		/* S: Page referenced */
 #define _PAGE_DIRTY	0x00000010		/* S: Page dirty */
+#define _PAGE_SPECIAL	0x00000020		/* S: Special page */
 #define _PAGE_USER	0x00000040		/* S: User page */
 #define _PAGE_ENDIAN	0x00000080		/* H: E bit */
 #define _PAGE_GUARDED	0x00000100		/* H: G bit */
@@ -276,6 +277,7 @@ extern int icache_44x_need_flush;
 /* ERPN in a PTE never gets cleared, ignore it */
 #define _PTE_NONE_MASK	0xffffffff00000000ULL
 
+#define __HAVE_ARCH_PTE_SPECIAL
 
 #elif defined(CONFIG_FSL_BOOKE)
 /*
@@ -305,6 +307,7 @@ extern int icache_44x_need_flush;
 #define _PAGE_COHERENT	0x00100	/* H: M bit */
 #define _PAGE_NO_CACHE	0x00200	/* H: I bit */
 #define _PAGE_WRITETHRU	0x00400	/* H: W bit */
+#define _PAGE_SPECIAL	0x00800 /* S: Special page */
 
 #ifdef CONFIG_PTE_64BIT
 /* ERPN in a PTE never gets cleared, ignore it */
@@ -315,6 +318,8 @@ extern int icache_44x_need_flush;
 #define _PMD_PRESENT_MASK (PAGE_MASK)
 #define _PMD_BAD	(~PAGE_MASK)
 
+#define __HAVE_ARCH_PTE_SPECIAL
+
 #elif defined(CONFIG_8xx)
 /* Definitions for 8xx embedded chips. */
 #define _PAGE_PRESENT	0x0001	/* Page is valid */
@@ -362,6 +367,7 @@ extern int icache_44x_need_flush;
 #define _PAGE_ACCESSED	0x100	/* R: page referenced */
 #define _PAGE_EXEC	0x200	/* software: i-cache coherency required */
 #define _PAGE_RW	0x400	/* software: user write access allowed */
+#define _PAGE_SPECIAL	0x800	/* software: Special page */
 
 #define _PTE_NONE_MASK	_PAGE_HASHPTE
 
@@ -372,6 +378,8 @@ extern int icache_44x_need_flush;
 /* Hash table based platforms need atomic updates of the linux PTE */
 #define PTE_ATOMIC_UPDATES	1
 
+#define __HAVE_ARCH_PTE_SPECIAL
+
 #endif
 
 /*
@@ -404,6 +412,9 @@ extern int icache_44x_need_flush;
 #ifndef _PAGE_WRITETHRU
 #define _PAGE_WRITETHRU	0
 #endif
+#ifndef _PAGE_SPECIAL
+#define _PAGE_SPECIAL	0
+#endif
 #ifndef _PMD_PRESENT_MASK
 #define _PMD_PRESENT_MASK	_PMD_PRESENT
 #endif
@@ -534,7 +545,7 @@ static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_RW; }
 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
 static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
 static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }
-static inline int pte_special(pte_t pte)	{ return 0; }
+static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
 
 static inline void pte_uncache(pte_t pte)       { pte_val(pte) |= _PAGE_NO_CACHE; }
 static inline void pte_cache(pte_t pte)         { pte_val(pte) &= ~_PAGE_NO_CACHE; }
@@ -553,7 +564,7 @@ static inline pte_t pte_mkdirty(pte_t pte) {
 static inline pte_t pte_mkyoung(pte_t pte) {
 	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
 static inline pte_t pte_mkspecial(pte_t pte) {
-	return pte; }
+	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
 static inline unsigned long pte_pgprot(pte_t pte)
 {
 	return __pgprot(pte_val(pte)) & PAGE_PROT_BITS;
-- 
1.5.5.1

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH v9 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support
  2008-09-19  0:09 ` [PATCH v9 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support Kumar Gala
  2008-09-19  0:09   ` [PATCH v9 3/4] powerpc/fsl-booke: Fixup 64-bit PTE reading " Kumar Gala
@ 2008-09-23 16:13   ` Becky Bruce
  1 sibling, 0 replies; 5+ messages in thread
From: Becky Bruce @ 2008-09-23 16:13 UTC (permalink / raw)
  To: Kumar Gala; +Cc: linuxppc-dev


On Sep 18, 2008, at 7:09 PM, Kumar Gala wrote:

> There are some minor issues with support 64-bit PTEs on a 32-bit  
> processor
> when dealing with SMP.
>
> * We need to order the stores in set_pte_at to make sure the flag word
>  is set second.
> * Change pte_clear to use pte_update so only the flag word is cleared
> * Added a WARN_ON to set_pte_at to ensure the pte isn't present for
>  the 64-bit pte/SMP case (to ensure our assumption of this fact).
>
> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

This looks like what we discussed; and I've rebased my 8641 work on
top of it and am building and booting and LTP-ing like a champ. So....

Acked-by: Becky Bruce <becky.bruce!freescale.com>

Cheers,
B

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2008-09-23 16:13 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2008-09-19  0:09 [PATCH v9 1/4] powerpc: Introduce local (non-broadcast) forms of tlb invalidates Kumar Gala
2008-09-19  0:09 ` [PATCH v9 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support Kumar Gala
2008-09-19  0:09   ` [PATCH v9 3/4] powerpc/fsl-booke: Fixup 64-bit PTE reading " Kumar Gala
2008-09-19  0:09     ` [PATCH v9 4/4] powerpc/mm: Implement _PAGE_SPECIAL & pte_special() for 32-bit Kumar Gala
2008-09-23 16:13   ` [PATCH v9 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support Becky Bruce

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).