From 4b3073e1c53a256275f1079c0fbfbe85883d9275 Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 18 Dec 2009 16:40:18 +0000 Subject: MM: Pass a PTE pointer to update_mmu_cache() rather than the PTE itself On VIVT ARM, when we have multiple shared mappings of the same file in the same MM, we need to ensure that we have coherency across all copies. We do this via make_coherent() by making the pages uncacheable. This used to work fine, until we allowed highmem with highpte - we now have a page table which is mapped as required, and is not available for modification via update_mmu_cache(). Ralf Beache suggested getting rid of the PTE value passed to update_mmu_cache(): On MIPS update_mmu_cache() calls __update_tlb() which walks pagetables to construct a pointer to the pte again. Passing a pte_t * is much more elegant. Maybe we might even replace the pte argument with the pte_t? Ben Herrenschmidt would also like the pte pointer for PowerPC: Passing the ptep in there is exactly what I want. I want that -instead- of the PTE value, because I have issue on some ppc cases, for I$/D$ coherency, where set_pte_at() may decide to mask out the _PAGE_EXEC. So, pass in the mapped page table pointer into update_mmu_cache(), and remove the PTE value, updating all implementations and call sites to suit. Includes a fix from Stephen Rothwell: sparc: fix fallout from update_mmu_cache API change Signed-off-by: Stephen Rothwell Acked-by: Benjamin Herrenschmidt Signed-off-by: Russell King --- arch/x86/include/asm/pgtable_32.h | 2 +- arch/x86/include/asm/pgtable_64.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h index 01fd9461d323..a28668396508 100644 --- a/arch/x86/include/asm/pgtable_32.h +++ b/arch/x86/include/asm/pgtable_32.h @@ -80,7 +80,7 @@ do { \ * The i386 doesn't have any external MMU info: the kernel page * tables contain all the necessary information. */ -#define update_mmu_cache(vma, address, pte) do { } while (0) +#define update_mmu_cache(vma, address, ptep) do { } while (0) #endif /* !__ASSEMBLY__ */ diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index c57a30117149..181be528c612 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -129,7 +129,7 @@ static inline int pgd_large(pgd_t pgd) { return 0; } #define pte_unmap(pte) /* NOP */ #define pte_unmap_nested(pte) /* NOP */ -#define update_mmu_cache(vma, address, pte) do { } while (0) +#define update_mmu_cache(vma, address, ptep) do { } while (0) /* Encode and de-code a swap entry */ #if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE -- cgit v1.2.3