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| author | Kumar Gala <galak@kernel.crashing.org> | 2008-07-16 22:54:21 +0200 |
|---|---|---|
| committer | Kumar Gala <galak@kernel.crashing.org> | 2008-09-24 23:29:41 +0200 |
| commit | 9bf2b5cdc5fe5e3136ceeecc85141765023ded6e (patch) | |
| tree | e1e25d6aa5a18ca63314192173d93cc0d20ac066 | |
| parent | powerpc: Introduce local (non-broadcast) forms of tlb invalidates (diff) | |
| download | linux-9bf2b5cdc5fe5e3136ceeecc85141765023ded6e.tar.xz linux-9bf2b5cdc5fe5e3136ceeecc85141765023ded6e.zip | |
powerpc: Fixes for CONFIG_PTE_64BIT for SMP support
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>
Acked-by: Becky Bruce <becky.bruce@freescale.com>
| -rw-r--r-- | arch/powerpc/include/asm/highmem.h | 2 | ||||
| -rw-r--r-- | 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 5d99b6489d56..91c589520c0a 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 6fe39e327047..1b1195555473 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. |