linux/include/linux/highmem.h
<<
>>
Prefs
   1#ifndef _LINUX_HIGHMEM_H
   2#define _LINUX_HIGHMEM_H
   3
   4#include <linux/fs.h>
   5#include <linux/kernel.h>
   6#include <linux/mm.h>
   7#include <linux/uaccess.h>
   8#include <linux/hardirq.h>
   9
  10#include <asm/cacheflush.h>
  11
  12#ifndef ARCH_HAS_FLUSH_ANON_PAGE
  13static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
  14{
  15}
  16#endif
  17
  18#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
  19static inline void flush_kernel_dcache_page(struct page *page)
  20{
  21}
  22static inline void flush_kernel_vmap_range(void *vaddr, int size)
  23{
  24}
  25static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
  26{
  27}
  28#endif
  29
  30#include <asm/kmap_types.h>
  31
  32#ifdef CONFIG_HIGHMEM
  33#include <asm/highmem.h>
  34
  35/* declarations for linux/mm/highmem.c */
  36unsigned int nr_free_highpages(void);
  37extern unsigned long totalhigh_pages;
  38
  39void kmap_flush_unused(void);
  40
  41#else /* CONFIG_HIGHMEM */
  42
  43static inline unsigned int nr_free_highpages(void) { return 0; }
  44
  45#define totalhigh_pages 0UL
  46
  47#ifndef ARCH_HAS_KMAP
  48static inline void *kmap(struct page *page)
  49{
  50        might_sleep();
  51        return page_address(page);
  52}
  53
  54static inline void kunmap(struct page *page)
  55{
  56}
  57
  58static inline void *__kmap_atomic(struct page *page)
  59{
  60        pagefault_disable();
  61        return page_address(page);
  62}
  63#define kmap_atomic_prot(page, prot)    __kmap_atomic(page)
  64
  65static inline void __kunmap_atomic(void *addr)
  66{
  67        pagefault_enable();
  68}
  69
  70#define kmap_atomic_pfn(pfn)    kmap_atomic(pfn_to_page(pfn))
  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#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
  79
  80DECLARE_PER_CPU(int, __kmap_atomic_idx);
  81
  82static inline int kmap_atomic_idx_push(void)
  83{
  84        int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
  85
  86#ifdef CONFIG_DEBUG_HIGHMEM
  87        WARN_ON_ONCE(in_irq() && !irqs_disabled());
  88        BUG_ON(idx > KM_TYPE_NR);
  89#endif
  90        return idx;
  91}
  92
  93static inline int kmap_atomic_idx(void)
  94{
  95        return __this_cpu_read(__kmap_atomic_idx) - 1;
  96}
  97
  98static inline void kmap_atomic_idx_pop(void)
  99{
 100#ifdef CONFIG_DEBUG_HIGHMEM
 101        int idx = __this_cpu_dec_return(__kmap_atomic_idx);
 102
 103        BUG_ON(idx < 0);
 104#else
 105        __this_cpu_dec(__kmap_atomic_idx);
 106#endif
 107}
 108
 109#endif
 110
 111/*
 112 * Make both: kmap_atomic(page, idx) and kmap_atomic(page) work.
 113 */
 114#define kmap_atomic(page, args...) __kmap_atomic(page)
 115
 116/*
 117 * Prevent people trying to call kunmap_atomic() as if it were kunmap()
 118 * kunmap_atomic() should get the return value of kmap_atomic, not the page.
 119 */
 120#define kunmap_atomic(addr, args...)                            \
 121do {                                                            \
 122        BUILD_BUG_ON(__same_type((addr), struct page *));       \
 123        __kunmap_atomic(addr);                                  \
 124} while (0)
 125
 126/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
 127#ifndef clear_user_highpage
 128static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
 129{
 130        void *addr = kmap_atomic(page, KM_USER0);
 131        clear_user_page(addr, vaddr, page);
 132        kunmap_atomic(addr, KM_USER0);
 133}
 134#endif
 135
 136#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
 137/**
 138 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
 139 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
 140 * @vma: The VMA the page is to be allocated for
 141 * @vaddr: The virtual address the page will be inserted into
 142 *
 143 * This function will allocate a page for a VMA but the caller is expected
 144 * to specify via movableflags whether the page will be movable in the
 145 * future or not
 146 *
 147 * An architecture may override this function by defining
 148 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
 149 * implementation.
 150 */
 151static inline struct page *
 152__alloc_zeroed_user_highpage(gfp_t movableflags,
 153                        struct vm_area_struct *vma,
 154                        unsigned long vaddr)
 155{
 156        struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
 157                        vma, vaddr);
 158
 159        if (page)
 160                clear_user_highpage(page, vaddr);
 161
 162        return page;
 163}
 164#endif
 165
 166/**
 167 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
 168 * @vma: The VMA the page is to be allocated for
 169 * @vaddr: The virtual address the page will be inserted into
 170 *
 171 * This function will allocate a page for a VMA that the caller knows will
 172 * be able to migrate in the future using move_pages() or reclaimed
 173 */
 174static inline struct page *
 175alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
 176                                        unsigned long vaddr)
 177{
 178        return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
 179}
 180
 181static inline void clear_highpage(struct page *page)
 182{
 183        void *kaddr = kmap_atomic(page, KM_USER0);
 184        clear_page(kaddr);
 185        kunmap_atomic(kaddr, KM_USER0);
 186}
 187
 188static inline void zero_user_segments(struct page *page,
 189        unsigned start1, unsigned end1,
 190        unsigned start2, unsigned end2)
 191{
 192        void *kaddr = kmap_atomic(page, KM_USER0);
 193
 194        BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
 195
 196        if (end1 > start1)
 197                memset(kaddr + start1, 0, end1 - start1);
 198
 199        if (end2 > start2)
 200                memset(kaddr + start2, 0, end2 - start2);
 201
 202        kunmap_atomic(kaddr, KM_USER0);
 203        flush_dcache_page(page);
 204}
 205
 206static inline void zero_user_segment(struct page *page,
 207        unsigned start, unsigned end)
 208{
 209        zero_user_segments(page, start, end, 0, 0);
 210}
 211
 212static inline void zero_user(struct page *page,
 213        unsigned start, unsigned size)
 214{
 215        zero_user_segments(page, start, start + size, 0, 0);
 216}
 217
 218static inline void __deprecated memclear_highpage_flush(struct page *page,
 219                        unsigned int offset, unsigned int size)
 220{
 221        zero_user(page, offset, size);
 222}
 223
 224#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
 225
 226static inline void copy_user_highpage(struct page *to, struct page *from,
 227        unsigned long vaddr, struct vm_area_struct *vma)
 228{
 229        char *vfrom, *vto;
 230
 231        vfrom = kmap_atomic(from, KM_USER0);
 232        vto = kmap_atomic(to, KM_USER1);
 233        copy_user_page(vto, vfrom, vaddr, to);
 234        kunmap_atomic(vto, KM_USER1);
 235        kunmap_atomic(vfrom, KM_USER0);
 236}
 237
 238#endif
 239
 240static inline void copy_highpage(struct page *to, struct page *from)
 241{
 242        char *vfrom, *vto;
 243
 244        vfrom = kmap_atomic(from, KM_USER0);
 245        vto = kmap_atomic(to, KM_USER1);
 246        copy_page(vto, vfrom);
 247        kunmap_atomic(vto, KM_USER1);
 248        kunmap_atomic(vfrom, KM_USER0);
 249}
 250
 251#endif /* _LINUX_HIGHMEM_H */
 252
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.