1 #ifndef _LINUX_HIGHMEM_H 2 #define _LINUX_HIGHMEM_H 3 4 #include <linux/fs.h> 5 #include <linux/mm.h> 6 #include <linux/uaccess.h> 7 8 #include <asm/cacheflush.h> 9 10 #ifndef ARCH_HAS_FLUSH_ANON_PAGE 11 static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr) 12 { 13 } 14 #endif 15 16 #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE 17 static inline void flush_kernel_dcache_page(struct page *page) 18 { 19 } 20 static inline void flush_kernel_vmap_range(void *vaddr, int size) 21 { 22 } 23 static inline void invalidate_kernel_vmap_range(void *vaddr, int size) 24 { 25 } 26 #endif 27 28 #include <asm/kmap_types.h> 29 30 #if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT) 31 32 void debug_kmap_atomic(enum km_type type); 33 34 #else 35 36 static inline void debug_kmap_atomic(enum km_type type) 37 { 38 } 39 40 #endif 41 42 #ifdef CONFIG_HIGHMEM 43 #include <asm/highmem.h> 44 45 /* declarations for linux/mm/highmem.c */ 46 unsigned int nr_free_highpages(void); 47 extern unsigned long totalhigh_pages; 48 49 void kmap_flush_unused(void); 50 51 #else /* CONFIG_HIGHMEM */ 52 53 static inline unsigned int nr_free_highpages(void) { return 0; } 54 55 #define totalhigh_pages 0UL 56 57 #ifndef ARCH_HAS_KMAP 58 static inline void *kmap(struct page *page) 59 { 60 might_sleep(); 61 return page_address(page); 62 } 63 64 static inline void kunmap(struct page *page) 65 { 66 } 67 68 static inline void *kmap_atomic(struct page *page, enum km_type idx) 69 { 70 pagefault_disable(); 71 return page_address(page); 72 } 73 #define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx) 74 75 #define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0) 76 #define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx)) 77 #define kmap_atomic_to_page(ptr) virt_to_page(ptr) 78 79 #define kmap_flush_unused() do {} while(0) 80 #endif 81 82 #endif /* CONFIG_HIGHMEM */ 83 84 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ 85 #ifndef clear_user_highpage 86 static inline void clear_user_highpage(struct page *page, unsigned long vaddr) 87 { 88 void *addr = kmap_atomic(page, KM_USER0); 89 clear_user_page(addr, vaddr, page); 90 kunmap_atomic(addr, KM_USER0); 91 } 92 #endif 93 94 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE 95 /** 96 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags 97 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE 98 * @vma: The VMA the page is to be allocated for 99 * @vaddr: The virtual address the page will be inserted into 100 * 101 * This function will allocate a page for a VMA but the caller is expected 102 * to specify via movableflags whether the page will be movable in the 103 * future or not 104 * 105 * An architecture may override this function by defining 106 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own 107 * implementation. 108 */ 109 static inline struct page * 110 __alloc_zeroed_user_highpage(gfp_t movableflags, 111 struct vm_area_struct *vma, 112 unsigned long vaddr) 113 { 114 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags, 115 vma, vaddr); 116 117 if (page) 118 clear_user_highpage(page, vaddr); 119 120 return page; 121 } 122 #endif 123 124 /** 125 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move 126 * @vma: The VMA the page is to be allocated for 127 * @vaddr: The virtual address the page will be inserted into 128 * 129 * This function will allocate a page for a VMA that the caller knows will 130 * be able to migrate in the future using move_pages() or reclaimed 131 */ 132 static inline struct page * 133 alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, 134 unsigned long vaddr) 135 { 136 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr); 137 } 138 139 static inline void clear_highpage(struct page *page) 140 { 141 void *kaddr = kmap_atomic(page, KM_USER0); 142 clear_page(kaddr); 143 kunmap_atomic(kaddr, KM_USER0); 144 } 145 146 static inline void zero_user_segments(struct page *page, 147 unsigned start1, unsigned end1, 148 unsigned start2, unsigned end2) 149 { 150 void *kaddr = kmap_atomic(page, KM_USER0); 151 152 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE); 153 154 if (end1 > start1) 155 memset(kaddr + start1, 0, end1 - start1); 156 157 if (end2 > start2) 158 memset(kaddr + start2, 0, end2 - start2); 159 160 kunmap_atomic(kaddr, KM_USER0); 161 flush_dcache_page(page); 162 } 163 164 static inline void zero_user_segment(struct page *page, 165 unsigned start, unsigned end) 166 { 167 zero_user_segments(page, start, end, 0, 0); 168 } 169 170 static inline void zero_user(struct page *page, 171 unsigned start, unsigned size) 172 { 173 zero_user_segments(page, start, start + size, 0, 0); 174 } 175 176 static inline void __deprecated memclear_highpage_flush(struct page *page, 177 unsigned int offset, unsigned int size) 178 { 179 zero_user(page, offset, size); 180 } 181 182 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE 183 184 static inline void copy_user_highpage(struct page *to, struct page *from, 185 unsigned long vaddr, struct vm_area_struct *vma) 186 { 187 char *vfrom, *vto; 188 189 vfrom = kmap_atomic(from, KM_USER0); 190 vto = kmap_atomic(to, KM_USER1); 191 copy_user_page(vto, vfrom, vaddr, to); 192 kunmap_atomic(vfrom, KM_USER0); 193 kunmap_atomic(vto, KM_USER1); 194 } 195 196 #endif 197 198 static inline void copy_highpage(struct page *to, struct page *from) 199 { 200 char *vfrom, *vto; 201 202 vfrom = kmap_atomic(from, KM_USER0); 203 vto = kmap_atomic(to, KM_USER1); 204 copy_page(vto, vfrom); 205 kunmap_atomic(vfrom, KM_USER0); 206 kunmap_atomic(vto, KM_USER1); 207 } 208 209 #endif /* _LINUX_HIGHMEM_H */ 210