[PATCH v2 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support
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STALE6631d
From: Kumar Gala <hidden>
Date: 2008-08-29 13:56:59
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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
Signed-off-by: Kumar Gala <redacted>
---
arch/powerpc/include/asm/pgtable-ppc32.h | 14 ++++++++++----
1 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index 6fe39e3..db2e7bd 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h@@ -517,7 +517,7 @@ 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, ~0, 0); } while (0) #define pmd_none(pmd) (!pmd_val(pmd)) #define pmd_bad(pmd) (pmd_val(pmd) & _PMD_BAD)
@@ -612,9 +612,6 @@ 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)
@@ -658,8 +655,17 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, #if _PAGE_HASHPTE != 0 pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte) & ~_PAGE_HASHPTE); #else +#if 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 +#endif } /*
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1.5.5.1