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 preempt_disable(); 69 pagefault_disable(); 70 return page_address(page); 71 } 72 #define kmap_atomic_prot(page, prot) kmap_atomic(page) 73 74 static inline void __kunmap_atomic(void *addr) 75 { 76 pagefault_enable(); 77 preempt_enable(); 78 } 79 80 #define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn)) 81 82 #define kmap_flush_unused() do {} while(0) 83 #endif 84 85 #endif /* CONFIG_HIGHMEM */ 86 87 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) 88 89 DECLARE_PER_CPU(int, __kmap_atomic_idx); 90 91 static inline int kmap_atomic_idx_push(void) 92 { 93 int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1; 94 95 #ifdef CONFIG_DEBUG_HIGHMEM 96 WARN_ON_ONCE(in_irq() && !irqs_disabled()); 97 BUG_ON(idx >= KM_TYPE_NR); 98 #endif 99 return idx; 100 } 101 102 static inline int kmap_atomic_idx(void) 103 { 104 return __this_cpu_read(__kmap_atomic_idx) - 1; 105 } 106 107 static inline void kmap_atomic_idx_pop(void) 108 { 109 #ifdef CONFIG_DEBUG_HIGHMEM 110 int idx = __this_cpu_dec_return(__kmap_atomic_idx); 111 112 BUG_ON(idx < 0); 113 #else 114 __this_cpu_dec(__kmap_atomic_idx); 115 #endif 116 } 117 118 #endif 119 120 /* 121 * Prevent people trying to call kunmap_atomic() as if it were kunmap() 122 * kunmap_atomic() should get the return value of kmap_atomic, not the page. 123 */ 124 #define kunmap_atomic(addr) \ 125 do { \ 126 BUILD_BUG_ON(__same_type((addr), struct page *)); \ 127 __kunmap_atomic(addr); \ 128 } while (0) 129 130 131 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ 132 #ifndef clear_user_highpage 133 static inline void clear_user_highpage(struct page *page, unsigned long vaddr) 134 { 135 void *addr = kmap_atomic(page); 136 clear_user_page(addr, vaddr, page); 137 kunmap_atomic(addr); 138 } 139 #endif 140 141 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE 142 /** 143 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags 144 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE 145 * @vma: The VMA the page is to be allocated for 146 * @vaddr: The virtual address the page will be inserted into 147 * 148 * This function will allocate a page for a VMA but the caller is expected 149 * to specify via movableflags whether the page will be movable in the 150 * future or not 151 * 152 * An architecture may override this function by defining 153 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own 154 * implementation. 155 */ 156 static inline struct page * 157 __alloc_zeroed_user_highpage(gfp_t movableflags, 158 struct vm_area_struct *vma, 159 unsigned long vaddr) 160 { 161 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags, 162 vma, vaddr); 163 164 if (page) 165 clear_user_highpage(page, vaddr); 166 167 return page; 168 } 169 #endif 170 171 /** 172 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move 173 * @vma: The VMA the page is to be allocated for 174 * @vaddr: The virtual address the page will be inserted into 175 * 176 * This function will allocate a page for a VMA that the caller knows will 177 * be able to migrate in the future using move_pages() or reclaimed 178 */ 179 static inline struct page * 180 alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, 181 unsigned long vaddr) 182 { 183 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr); 184 } 185 186 static inline void clear_highpage(struct page *page) 187 { 188 void *kaddr = kmap_atomic(page); 189 clear_page(kaddr); 190 kunmap_atomic(kaddr); 191 } 192 193 static inline void zero_user_segments(struct page *page, 194 unsigned start1, unsigned end1, 195 unsigned start2, unsigned end2) 196 { 197 void *kaddr = kmap_atomic(page); 198 199 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE); 200 201 if (end1 > start1) 202 memset(kaddr + start1, 0, end1 - start1); 203 204 if (end2 > start2) 205 memset(kaddr + start2, 0, end2 - start2); 206 207 kunmap_atomic(kaddr); 208 flush_dcache_page(page); 209 } 210 211 static inline void zero_user_segment(struct page *page, 212 unsigned start, unsigned end) 213 { 214 zero_user_segments(page, start, end, 0, 0); 215 } 216 217 static inline void zero_user(struct page *page, 218 unsigned start, unsigned size) 219 { 220 zero_user_segments(page, start, start + size, 0, 0); 221 } 222 223 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE 224 225 static inline void copy_user_highpage(struct page *to, struct page *from, 226 unsigned long vaddr, struct vm_area_struct *vma) 227 { 228 char *vfrom, *vto; 229 230 vfrom = kmap_atomic(from); 231 vto = kmap_atomic(to); 232 copy_user_page(vto, vfrom, vaddr, to); 233 kunmap_atomic(vto); 234 kunmap_atomic(vfrom); 235 } 236 237 #endif 238 239 static inline void copy_highpage(struct page *to, struct page *from) 240 { 241 char *vfrom, *vto; 242 243 vfrom = kmap_atomic(from); 244 vto = kmap_atomic(to); 245 copy_page(vto, vfrom); 246 kunmap_atomic(vto); 247 kunmap_atomic(vfrom); 248 } 249 250 #endif /* _LINUX_HIGHMEM_H */ 251