1 #ifndef _LINUX_HIGHMEM_H 2 #define _LINUX_HIGHMEM_H 3 4 #include <linux/config.h> 5 #include <linux/fs.h> 6 #include <linux/mm.h> 7 8 #include <asm/cacheflush.h> 9 10 #ifdef CONFIG_HIGHMEM 11 12 #include <asm/highmem.h> 13 14 /* declarations for linux/mm/highmem.c */ 15 unsigned int nr_free_highpages(void); 16 17 #else /* CONFIG_HIGHMEM */ 18 19 static inline unsigned int nr_free_highpages(void) { return 0; } 20 21 static inline void *kmap(struct page *page) 22 { 23 might_sleep(); 24 return page_address(page); 25 } 26 27 #define kunmap(page) do { (void) (page); } while (0) 28 29 #define kmap_atomic(page, idx) page_address(page) 30 #define kunmap_atomic(addr, idx) do { } while (0) 31 #define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn)) 32 #define kmap_atomic_to_page(ptr) virt_to_page(ptr) 33 34 #endif /* CONFIG_HIGHMEM */ 35 36 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ 37 static inline void clear_user_highpage(struct page *page, unsigned long vaddr) 38 { 39 void *addr = kmap_atomic(page, KM_USER0); 40 clear_user_page(addr, vaddr, page); 41 kunmap_atomic(addr, KM_USER0); 42 /* Make sure this page is cleared on other CPU's too before using it */ 43 smp_wmb(); 44 } 45 46 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE 47 static inline struct page * 48 alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) 49 { 50 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); 51 52 if (page) 53 clear_user_highpage(page, vaddr); 54 55 return page; 56 } 57 #endif 58 59 static inline void clear_highpage(struct page *page) 60 { 61 void *kaddr = kmap_atomic(page, KM_USER0); 62 clear_page(kaddr); 63 kunmap_atomic(kaddr, KM_USER0); 64 } 65 66 /* 67 * Same but also flushes aliased cache contents to RAM. 68 */ 69 static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size) 70 { 71 void *kaddr; 72 73 BUG_ON(offset + size > PAGE_SIZE); 74 75 kaddr = kmap_atomic(page, KM_USER0); 76 memset((char *)kaddr + offset, 0, size); 77 flush_dcache_page(page); 78 kunmap_atomic(kaddr, KM_USER0); 79 } 80 81 static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr) 82 { 83 char *vfrom, *vto; 84 85 vfrom = kmap_atomic(from, KM_USER0); 86 vto = kmap_atomic(to, KM_USER1); 87 copy_user_page(vto, vfrom, vaddr, to); 88 kunmap_atomic(vfrom, KM_USER0); 89 kunmap_atomic(vto, KM_USER1); 90 /* Make sure this page is cleared on other CPU's too before using it */ 91 smp_wmb(); 92 } 93 94 static inline void copy_highpage(struct page *to, struct page *from) 95 { 96 char *vfrom, *vto; 97 98 vfrom = kmap_atomic(from, KM_USER0); 99 vto = kmap_atomic(to, KM_USER1); 100 copy_page(vto, vfrom); 101 kunmap_atomic(vfrom, KM_USER0); 102 kunmap_atomic(vto, KM_USER1); 103 } 104 105 #endif /* _LINUX_HIGHMEM_H */ 106