1 #ifndef _LINUX_HIGHMEM_H
2 #define _LINUX_HIGHMEM_H
5 #include <linux/kernel.h>
8 #include <linux/uaccess.h>
9 #include <linux/hardirq.h>
11 #include <asm/cacheflush.h>
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)
19 #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
20 static inline void flush_kernel_dcache_page(struct page *page)
23 static inline void flush_kernel_vmap_range(void *vaddr, int size)
26 static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
31 #include <asm/kmap_types.h>
34 #include <asm/highmem.h>
36 /* declarations for linux/mm/highmem.c */
37 unsigned int nr_free_highpages(void);
38 extern unsigned long totalhigh_pages;
40 void kmap_flush_unused(void);
42 struct page *kmap_to_page(void *addr);
44 #else /* CONFIG_HIGHMEM */
46 static inline unsigned int nr_free_highpages(void) { return 0; }
48 static inline struct page *kmap_to_page(void *addr)
50 return virt_to_page(addr);
53 #define totalhigh_pages 0UL
56 static inline void *kmap(struct page *page)
59 return page_address(page);
62 static inline void kunmap(struct page *page)
66 static inline void *kmap_atomic(struct page *page)
70 return page_address(page);
72 #define kmap_atomic_prot(page, prot) kmap_atomic(page)
74 static inline void __kunmap_atomic(void *addr)
80 #define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
81 #define kmap_atomic_to_page(ptr) virt_to_page(ptr)
83 #define kmap_flush_unused() do {} while(0)
86 #endif /* CONFIG_HIGHMEM */
88 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
90 DECLARE_PER_CPU(int, __kmap_atomic_idx);
92 static inline int kmap_atomic_idx_push(void)
94 int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
96 #ifdef CONFIG_DEBUG_HIGHMEM
97 WARN_ON_ONCE(in_irq() && !irqs_disabled());
98 BUG_ON(idx >= KM_TYPE_NR);
103 static inline int kmap_atomic_idx(void)
105 return __this_cpu_read(__kmap_atomic_idx) - 1;
108 static inline void kmap_atomic_idx_pop(void)
110 #ifdef CONFIG_DEBUG_HIGHMEM
111 int idx = __this_cpu_dec_return(__kmap_atomic_idx);
115 __this_cpu_dec(__kmap_atomic_idx);
122 * Prevent people trying to call kunmap_atomic() as if it were kunmap()
123 * kunmap_atomic() should get the return value of kmap_atomic, not the page.
125 #define kunmap_atomic(addr) \
127 BUILD_BUG_ON(__same_type((addr), struct page *)); \
128 __kunmap_atomic(addr); \
132 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
133 #ifndef clear_user_highpage
134 static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
136 void *addr = kmap_atomic(page);
137 clear_user_page(addr, vaddr, page);
142 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
144 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
145 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
146 * @vma: The VMA the page is to be allocated for
147 * @vaddr: The virtual address the page will be inserted into
149 * This function will allocate a page for a VMA but the caller is expected
150 * to specify via movableflags whether the page will be movable in the
153 * An architecture may override this function by defining
154 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
157 static inline struct page *
158 __alloc_zeroed_user_highpage(gfp_t movableflags,
159 struct vm_area_struct *vma,
162 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
166 clear_user_highpage(page, vaddr);
173 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
174 * @vma: The VMA the page is to be allocated for
175 * @vaddr: The virtual address the page will be inserted into
177 * This function will allocate a page for a VMA that the caller knows will
178 * be able to migrate in the future using move_pages() or reclaimed
180 static inline struct page *
181 alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
184 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
187 static inline void clear_highpage(struct page *page)
189 void *kaddr = kmap_atomic(page);
191 kunmap_atomic(kaddr);
194 static inline void zero_user_segments(struct page *page,
195 unsigned start1, unsigned end1,
196 unsigned start2, unsigned end2)
198 void *kaddr = kmap_atomic(page);
200 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
203 memset(kaddr + start1, 0, end1 - start1);
206 memset(kaddr + start2, 0, end2 - start2);
208 kunmap_atomic(kaddr);
209 flush_dcache_page(page);
212 static inline void zero_user_segment(struct page *page,
213 unsigned start, unsigned end)
215 zero_user_segments(page, start, end, 0, 0);
218 static inline void zero_user(struct page *page,
219 unsigned start, unsigned size)
221 zero_user_segments(page, start, start + size, 0, 0);
224 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
226 static inline void copy_user_highpage(struct page *to, struct page *from,
227 unsigned long vaddr, struct vm_area_struct *vma)
231 vfrom = kmap_atomic(from);
232 vto = kmap_atomic(to);
233 copy_user_page(vto, vfrom, vaddr, to);
235 kunmap_atomic(vfrom);
240 static inline void copy_highpage(struct page *to, struct page *from)
244 vfrom = kmap_atomic(from);
245 vto = kmap_atomic(to);
246 copy_page(vto, vfrom);
248 kunmap_atomic(vfrom);
251 #endif /* _LINUX_HIGHMEM_H */