1 #ifndef _LINUX_HIGHMEM_H
2 #define _LINUX_HIGHMEM_H
5 #include <linux/kernel.h>
7 #include <linux/uaccess.h>
9 #include <asm/cacheflush.h>
11 #ifndef ARCH_HAS_FLUSH_ANON_PAGE
12 static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
17 #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
18 static inline void flush_kernel_dcache_page(struct page *page)
21 static inline void flush_kernel_vmap_range(void *vaddr, int size)
24 static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
29 #include <asm/kmap_types.h>
31 #ifdef CONFIG_DEBUG_HIGHMEM
33 void debug_kmap_atomic(enum km_type type);
37 static inline void debug_kmap_atomic(enum km_type type)
44 #include <asm/highmem.h>
46 /* declarations for linux/mm/highmem.c */
47 unsigned int nr_free_highpages(void);
48 extern unsigned long totalhigh_pages;
50 void kmap_flush_unused(void);
52 #else /* CONFIG_HIGHMEM */
54 static inline unsigned int nr_free_highpages(void) { return 0; }
56 #define totalhigh_pages 0UL
59 static inline void *kmap(struct page *page)
62 return page_address(page);
65 static inline void kunmap(struct page *page)
69 static inline void *kmap_atomic(struct page *page, enum km_type idx)
72 return page_address(page);
74 #define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx)
76 #define kunmap_atomic_notypecheck(addr, idx) do { pagefault_enable(); } while (0)
77 #define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
78 #define kmap_atomic_to_page(ptr) virt_to_page(ptr)
80 #define kmap_flush_unused() do {} while(0)
83 #endif /* CONFIG_HIGHMEM */
85 /* Prevent people trying to call kunmap_atomic() as if it were kunmap() */
86 /* kunmap_atomic() should get the return value of kmap_atomic, not the page. */
87 #define kunmap_atomic(addr, idx) do { \
88 BUILD_BUG_ON(__same_type((addr), struct page *)); \
89 kunmap_atomic_notypecheck((addr), (idx)); \
92 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
93 #ifndef clear_user_highpage
94 static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
96 void *addr = kmap_atomic(page, KM_USER0);
97 clear_user_page(addr, vaddr, page);
98 kunmap_atomic(addr, KM_USER0);
102 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
104 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
105 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
106 * @vma: The VMA the page is to be allocated for
107 * @vaddr: The virtual address the page will be inserted into
109 * This function will allocate a page for a VMA but the caller is expected
110 * to specify via movableflags whether the page will be movable in the
113 * An architecture may override this function by defining
114 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
117 static inline struct page *
118 __alloc_zeroed_user_highpage(gfp_t movableflags,
119 struct vm_area_struct *vma,
122 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
126 clear_user_highpage(page, vaddr);
133 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
134 * @vma: The VMA the page is to be allocated for
135 * @vaddr: The virtual address the page will be inserted into
137 * This function will allocate a page for a VMA that the caller knows will
138 * be able to migrate in the future using move_pages() or reclaimed
140 static inline struct page *
141 alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
144 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
147 static inline void clear_highpage(struct page *page)
149 void *kaddr = kmap_atomic(page, KM_USER0);
151 kunmap_atomic(kaddr, KM_USER0);
154 static inline void zero_user_segments(struct page *page,
155 unsigned start1, unsigned end1,
156 unsigned start2, unsigned end2)
158 void *kaddr = kmap_atomic(page, KM_USER0);
160 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
163 memset(kaddr + start1, 0, end1 - start1);
166 memset(kaddr + start2, 0, end2 - start2);
168 kunmap_atomic(kaddr, KM_USER0);
169 flush_dcache_page(page);
172 static inline void zero_user_segment(struct page *page,
173 unsigned start, unsigned end)
175 zero_user_segments(page, start, end, 0, 0);
178 static inline void zero_user(struct page *page,
179 unsigned start, unsigned size)
181 zero_user_segments(page, start, start + size, 0, 0);
184 static inline void __deprecated memclear_highpage_flush(struct page *page,
185 unsigned int offset, unsigned int size)
187 zero_user(page, offset, size);
190 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
192 static inline void copy_user_highpage(struct page *to, struct page *from,
193 unsigned long vaddr, struct vm_area_struct *vma)
197 vfrom = kmap_atomic(from, KM_USER0);
198 vto = kmap_atomic(to, KM_USER1);
199 copy_user_page(vto, vfrom, vaddr, to);
200 kunmap_atomic(vfrom, KM_USER0);
201 kunmap_atomic(vto, KM_USER1);
206 static inline void copy_highpage(struct page *to, struct page *from)
210 vfrom = kmap_atomic(from, KM_USER0);
211 vto = kmap_atomic(to, KM_USER1);
212 copy_page(vto, vfrom);
213 kunmap_atomic(vfrom, KM_USER0);
214 kunmap_atomic(vto, KM_USER1);
217 #endif /* _LINUX_HIGHMEM_H */