include/linux/highmem.h

   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 #ifdef CONFIG_DEBUG_HIGHMEM
  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 */