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