diff options
| -rw-r--r-- | arch/parisc/kernel/cache.c | 24 | ||||
| -rw-r--r-- | include/asm-parisc/cacheflush.h | 35 |
2 files changed, 28 insertions, 31 deletions
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index e15f09eaed12..a065349aee37 100644 --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -270,7 +270,6 @@ void flush_dcache_page(struct page *page) unsigned long offset; unsigned long addr; pgoff_t pgoff; - pte_t *pte; unsigned long pfn = page_to_pfn(page); @@ -301,21 +300,16 @@ void flush_dcache_page(struct page *page) * taking a page fault if the pte doesn't exist. * This is just for speed. If the page translation * isn't there, there's no point exciting the - * nadtlb handler into a nullification frenzy */ - - - if(!(pte = translation_exists(mpnt, addr))) - continue; - - /* make sure we really have this page: the private + * nadtlb handler into a nullification frenzy. + * + * Make sure we really have this page: the private * mappings may cover this area but have COW'd this - * particular page */ - if(pte_pfn(*pte) != pfn) - continue; - - __flush_cache_page(mpnt, addr); - - break; + * particular page. + */ + if (translation_exists(mpnt, addr, pfn)) { + __flush_cache_page(mpnt, addr); + break; + } } flush_dcache_mmap_unlock(mapping); } diff --git a/include/asm-parisc/cacheflush.h b/include/asm-parisc/cacheflush.h index aa592d8c0e39..1bc3c83ee74b 100644 --- a/include/asm-parisc/cacheflush.h +++ b/include/asm-parisc/cacheflush.h @@ -100,30 +100,34 @@ static inline void flush_cache_range(struct vm_area_struct *vma, /* Simple function to work out if we have an existing address translation * for a user space vma. */ -static inline pte_t *__translation_exists(struct mm_struct *mm, - unsigned long addr) +static inline int translation_exists(struct vm_area_struct *vma, + unsigned long addr, unsigned long pfn) { - pgd_t *pgd = pgd_offset(mm, addr); + pgd_t *pgd = pgd_offset(vma->vm_mm, addr); pmd_t *pmd; - pte_t *pte; + pte_t pte; if(pgd_none(*pgd)) - return NULL; + return 0; pmd = pmd_offset(pgd, addr); if(pmd_none(*pmd) || pmd_bad(*pmd)) - return NULL; + return 0; - pte = pte_offset_map(pmd, addr); + /* We cannot take the pte lock here: flush_cache_page is usually + * called with pte lock already held. Whereas flush_dcache_page + * takes flush_dcache_mmap_lock, which is lower in the hierarchy: + * the vma itself is secure, but the pte might come or go racily. + */ + pte = *pte_offset_map(pmd, addr); + /* But pte_unmap() does nothing on this architecture */ - /* The PA flush mappings show up as pte_none, but they're - * valid none the less */ - if(pte_none(*pte) && ((pte_val(*pte) & _PAGE_FLUSH) == 0)) - return NULL; - return pte; -} -#define translation_exists(vma, addr) __translation_exists((vma)->vm_mm, addr) + /* Filter out coincidental file entries and swap entries */ + if (!(pte_val(pte) & (_PAGE_FLUSH|_PAGE_PRESENT))) + return 0; + return pte_pfn(pte) == pfn; +} /* Private function to flush a page from the cache of a non-current * process. cr25 contains the Page Directory of the current user @@ -175,9 +179,8 @@ flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long { BUG_ON(!vma->vm_mm->context); - if(likely(translation_exists(vma, vmaddr))) + if (likely(translation_exists(vma, vmaddr, pfn))) __flush_cache_page(vma, vmaddr); } #endif - |