diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/highmem.h | 33 | ||||
| -rw-r--r-- | include/linux/mm.h | 20 |
2 files changed, 53 insertions, 0 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 393bd51e5a1f..019ab7d8c841 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -218,6 +218,39 @@ static inline void clear_user_page(void *addr, unsigned long vaddr, struct page } #endif +/** + * clear_user_pages() - clear a page range to be mapped to user space + * @addr: start address + * @vaddr: start address of the user mapping + * @page: start page + * @npages: number of pages + * + * Assumes that the region (@addr, +@npages) has been validated + * already so this does no exception handling. + * + * If the architecture provides a clear_user_page(), use that; + * otherwise, we can safely use clear_pages(). + */ +static inline void clear_user_pages(void *addr, unsigned long vaddr, + struct page *page, unsigned int npages) +{ + +#ifdef clear_user_page + do { + clear_user_page(addr, vaddr, page); + addr += PAGE_SIZE; + vaddr += PAGE_SIZE; + page++; + } while (--npages); +#else + /* + * Prefer clear_pages() to allow for architectural optimizations + * when operating on contiguous page ranges. + */ + clear_pages(addr, npages); +#endif +} + /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ static inline void clear_user_highpage(struct page *page, unsigned long vaddr) { diff --git a/include/linux/mm.h b/include/linux/mm.h index f0d5be9dc736..d78e294698b0 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4198,6 +4198,26 @@ static inline void clear_page_guard(struct zone *zone, struct page *page, unsigned int order) {} #endif /* CONFIG_DEBUG_PAGEALLOC */ +#ifndef clear_pages +/** + * clear_pages() - clear a page range for kernel-internal use. + * @addr: start address + * @npages: number of pages + * + * Use clear_user_pages() instead when clearing a page range to be + * mapped to user space. + * + * Does absolutely no exception handling. + */ +static inline void clear_pages(void *addr, unsigned int npages) +{ + do { + clear_page(addr); + addr += PAGE_SIZE; + } while (--npages); +} +#endif + #ifdef __HAVE_ARCH_GATE_AREA extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm); extern int in_gate_area_no_mm(unsigned long addr); |