1 #ifndef _LINUX_HIGHMEM_H 2 #define _LINUX_HIGHMEM_H 3 4 #include <linux/fs.h> 5 #include <linux/kernel.h> 6 #include <linux/bug.h> 7 #include <linux/mm.h> 8 #include <linux/uaccess.h> 9 #include <linux/hardirq.h> 10 11 #include <asm/cacheflush.h> 12 13 #ifndef ARCH_HAS_FLUSH_ANON_PAGE 14 static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr) 15 { 16 } 17 #endif 18 19 #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE 20 static inline void flush_kernel_dcache_page(struct page *page) 21 { 22 } 23 static inline void flush_kernel_vmap_range(void *vaddr, int size) 24 { 25 } 26 static inline void invalidate_kernel_vmap_range(void *vaddr, int size) 27 { 28 } 29 #endif 30 31 #include <asm/kmap_types.h> 32 33 #ifdef CONFIG_HIGHMEM 34 #include <asm/highmem.h> 35 36 /* declarations for linux/mm/highmem.c */ 37 unsigned int nr_free_highpages(void); 38 extern unsigned long totalhigh_pages; 39 40 void kmap_flush_unused(void); 41 42 struct page *kmap_to_page(void *addr); 43 44 #else /* CONFIG_HIGHMEM */ 45 46 static inline unsigned int nr_free_highpages(void) { return 0; } 47 48 static inline struct page *kmap_to_page(void *addr) 49 { 50 return virt_to_page(addr); 51 } 52 53 #define totalhigh_pages 0UL 54 55 #ifndef ARCH_HAS_KMAP 56 static inline void *kmap(struct page *page) 57 { 58 might_sleep(); 59 return page_address(page); 60 } 61 62 static inline void kunmap(struct page *page) 63 { 64 } 65 66 static inline void *kmap_atomic(struct page *page) 67 { 68 pagefault_disable(); 69 return page_address(page); 70 } 71 #define kmap_atomic_prot(page, prot) kmap_atomic(page) 72 73 static inline void __kunmap_atomic(void *addr) 74 { 75 pagefault_enable(); 76 } 77 78 #define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn)) 79 #define kmap_atomic_to_page(ptr) virt_to_page(ptr) 80 81 #define kmap_flush_unused() do {} while(0) 82 #endif 83 84 #endif /* CONFIG_HIGHMEM */ 85 86 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) 87 88 DECLARE_PER_CPU(int, __kmap_atomic_idx); 89 90 static inline int kmap_atomic_idx_push(void) 91 { 92 int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1; 93 94 #ifdef CONFIG_DEBUG_HIGHMEM 95 WARN_ON_ONCE(in_irq() && !irqs_disabled()); 96 BUG_ON(idx > KM_TYPE_NR); 97 #endif 98 return idx; 99 } 100 101 static inline int kmap_atomic_idx(void) 102 { 103 return __this_cpu_read(__kmap_atomic_idx) - 1; 104 } 105 106 static inline void kmap_atomic_idx_pop(void) 107 { 108 #ifdef CONFIG_DEBUG_HIGHMEM 109 int idx = __this_cpu_dec_return(__kmap_atomic_idx); 110 111 BUG_ON(idx < 0); 112 #else 113 __this_cpu_dec(__kmap_atomic_idx); 114 #endif 115 } 116 117 #endif 118 119 /* 120 * Prevent people trying to call kunmap_atomic() as if it were kunmap() 121 * kunmap_atomic() should get the return value of kmap_atomic, not the page. 122 */ 123 #define kunmap_atomic(addr) \ 124 do { \ 125 BUILD_BUG_ON(__same_type((addr), struct page *)); \ 126 __kunmap_atomic(addr); \ 127 } while (0) 128 129 130 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ 131 #ifndef clear_user_highpage 132 static inline void clear_user_highpage(struct page *page, unsigned long vaddr) 133 { 134 void *addr = kmap_atomic(page); 135 clear_user_page(addr, vaddr, page); 136 kunmap_atomic(addr); 137 } 138 #endif 139 140 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE 141 /** 142 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags 143 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE 144 * @vma: The VMA the page is to be allocated for 145 * @vaddr: The virtual address the page will be inserted into 146 * 147 * This function will allocate a page for a VMA but the caller is expected 148 * to specify via movableflags whether the page will be movable in the 149 * future or not 150 * 151 * An architecture may override this function by defining 152 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own 153 * implementation. 154 */ 155 static inline struct page * 156 __alloc_zeroed_user_highpage(gfp_t movableflags, 157 struct vm_area_struct *vma, 158 unsigned long vaddr) 159 { 160 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags, 161 vma, vaddr); 162 163 if (page) 164 clear_user_highpage(page, vaddr); 165 166 return page; 167 } 168 #endif 169 170 /** 171 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move 172 * @vma: The VMA the page is to be allocated for 173 * @vaddr: The virtual address the page will be inserted into 174 * 175 * This function will allocate a page for a VMA that the caller knows will 176 * be able to migrate in the future using move_pages() or reclaimed 177 */ 178 static inline struct page * 179 alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, 180 unsigned long vaddr) 181 { 182 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr); 183 } 184 185 static inline void clear_highpage(struct page *page) 186 { 187 void *kaddr = kmap_atomic(page); 188 clear_page(kaddr); 189 kunmap_atomic(kaddr); 190 } 191 192 static inline void zero_user_segments(struct page *page, 193 unsigned start1, unsigned end1, 194 unsigned start2, unsigned end2) 195 { 196 void *kaddr = kmap_atomic(page); 197 198 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE); 199 200 if (end1 > start1) 201 memset(kaddr + start1, 0, end1 - start1); 202 203 if (end2 > start2) 204 memset(kaddr + start2, 0, end2 - start2); 205 206 kunmap_atomic(kaddr); 207 flush_dcache_page(page); 208 } 209 210 static inline void zero_user_segment(struct page *page, 211 unsigned start, unsigned end) 212 { 213 zero_user_segments(page, start, end, 0, 0); 214 } 215 216 static inline void zero_user(struct page *page, 217 unsigned start, unsigned size) 218 { 219 zero_user_segments(page, start, start + size, 0, 0); 220 } 221 222 static inline void __deprecated memclear_highpage_flush(struct page *page, 223 unsigned int offset, unsigned int size) 224 { 225 zero_user(page, offset, size); 226 } 227 228 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE 229 230 static inline void copy_user_highpage(struct page *to, struct page *from, 231 unsigned long vaddr, struct vm_area_struct *vma) 232 { 233 char *vfrom, *vto; 234 235 vfrom = kmap_atomic(from); 236 vto = kmap_atomic(to); 237 copy_user_page(vto, vfrom, vaddr, to); 238 kunmap_atomic(vto); 239 kunmap_atomic(vfrom); 240 } 241 242 #endif 243 244 static inline void copy_highpage(struct page *to, struct page *from) 245 { 246 char *vfrom, *vto; 247 248 vfrom = kmap_atomic(from); 249 vto = kmap_atomic(to); 250 copy_page(vto, vfrom); 251 kunmap_atomic(vto); 252 kunmap_atomic(vfrom); 253 } 254 255 #endif /* _LINUX_HIGHMEM_H */ 256