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