#ifndef _LINUX_HIGHMEM_H #define _LINUX_HIGHMEM_H #include <linux/config.h> #include <linux/fs.h> #include <linux/mm.h> #include <asm/cacheflush.h> #ifdef CONFIG_HIGHMEM #include <asm/highmem.h> /* declarations for linux/mm/highmem.c */ unsigned int nr_free_highpages(void); #else /* CONFIG_HIGHMEM */ static inline unsigned int nr_free_highpages(void) { return 0; } static inline void *kmap(struct page *page) { might_sleep(); return page_address(page); } #define kunmap(page) do { (void) (page); } while (0) #define kmap_atomic(page, idx) page_address(page) #define kunmap_atomic(addr, idx) do { } while (0) #define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn)) #define kmap_atomic_to_page(ptr) virt_to_page(ptr) #endif /* CONFIG_HIGHMEM */ /* 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) { void *addr = kmap_atomic(page, KM_USER0); clear_user_page(addr, vaddr, page); kunmap_atomic(addr, KM_USER0); /* Make sure this page is cleared on other CPU's too before using it */ smp_wmb(); } #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE static inline struct page * alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) { struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); if (page) clear_user_highpage(page, vaddr); return page; } #endif static inline void clear_highpage(struct page *page) { void *kaddr = kmap_atomic(page, KM_USER0); clear_page(kaddr); kunmap_atomic(kaddr, KM_USER0); } /* * Same but also flushes aliased cache contents to RAM. */ static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size) { void *kaddr; BUG_ON(offset + size > PAGE_SIZE); kaddr = kmap_atomic(page, KM_USER0); memset((char *)kaddr + offset, 0, size); flush_dcache_page(page); kunmap_atomic(kaddr, KM_USER0); } static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr) { char *vfrom, *vto; vfrom = kmap_atomic(from, KM_USER0); vto = kmap_atomic(to, KM_USER1); copy_user_page(vto, vfrom, vaddr, to); kunmap_atomic(vfrom, KM_USER0); kunmap_atomic(vto, KM_USER1); /* Make sure this page is cleared on other CPU's too before using it */ smp_wmb(); } static inline void copy_highpage(struct page *to, struct page *from) { char *vfrom, *vto; vfrom = kmap_atomic(from, KM_USER0); vto = kmap_atomic(to, KM_USER1); copy_page(vto, vfrom); kunmap_atomic(vfrom, KM_USER0); kunmap_atomic(vto, KM_USER1); } #endif /* _LINUX_HIGHMEM_H */