1 #ifndef _LINUX_HIGHMEM_H
2 #define _LINUX_HIGHMEM_H
5 #include <linux/kernel.h>
7 #include <linux/uaccess.h>
8 #include <linux/hardirq.h>
10 #include <asm/cacheflush.h>
12 #ifndef ARCH_HAS_FLUSH_ANON_PAGE
13 static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
18 #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
19 static inline void flush_kernel_dcache_page(struct page *page)
22 static inline void flush_kernel_vmap_range(void *vaddr, int size)
25 static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
30 #include <asm/kmap_types.h>
33 #include <asm/highmem.h>
35 /* declarations for linux/mm/highmem.c */
36 unsigned int nr_free_highpages(void);
37 extern unsigned long totalhigh_pages;
39 void kmap_flush_unused(void);
41 struct page *kmap_to_page(void *addr);
43 #else /* CONFIG_HIGHMEM */
45 static inline unsigned int nr_free_highpages(void) { return 0; }
47 static inline struct page *kmap_to_page(void *addr)
49 return virt_to_page(addr);
52 #define totalhigh_pages 0UL
55 static inline void *kmap(struct page *page)
58 return page_address(page);
61 static inline void kunmap(struct page *page)
65 static inline void *__kmap_atomic(struct page *page)
68 return page_address(page);
70 #define kmap_atomic_prot(page, prot) __kmap_atomic(page)
72 static inline void __kunmap_atomic(void *addr)
77 #define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
78 #define kmap_atomic_to_page(ptr) virt_to_page(ptr)
80 #define kmap_flush_unused() do {} while(0)
83 #endif /* CONFIG_HIGHMEM */
85 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
87 DECLARE_PER_CPU(int, __kmap_atomic_idx);
89 static inline int kmap_atomic_idx_push(void)
91 int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
93 #ifdef CONFIG_DEBUG_HIGHMEM
94 WARN_ON_ONCE(in_irq() && !irqs_disabled());
95 BUG_ON(idx > KM_TYPE_NR);
100 static inline int kmap_atomic_idx(void)
102 return __this_cpu_read(__kmap_atomic_idx) - 1;
105 static inline void kmap_atomic_idx_pop(void)
107 #ifdef CONFIG_DEBUG_HIGHMEM
108 int idx = __this_cpu_dec_return(__kmap_atomic_idx);
112 __this_cpu_dec(__kmap_atomic_idx);
119 * Make both: kmap_atomic(page, idx) and kmap_atomic(page) work.
121 #define kmap_atomic(page, args...) __kmap_atomic(page)
124 * Prevent people trying to call kunmap_atomic() as if it were kunmap()
125 * kunmap_atomic() should get the return value of kmap_atomic, not the page.
127 #define kunmap_atomic(addr, args...) \
129 BUILD_BUG_ON(__same_type((addr), struct page *)); \
130 __kunmap_atomic(addr); \
133 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
134 #ifndef clear_user_highpage
135 static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
137 void *addr = kmap_atomic(page, KM_USER0);
138 clear_user_page(addr, vaddr, page);
139 kunmap_atomic(addr, KM_USER0);
143 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
145 * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
146 * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
147 * @vma: The VMA the page is to be allocated for
148 * @vaddr: The virtual address the page will be inserted into
150 * This function will allocate a page for a VMA but the caller is expected
151 * to specify via movableflags whether the page will be movable in the
154 * An architecture may override this function by defining
155 * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
158 static inline struct page *
159 __alloc_zeroed_user_highpage(gfp_t movableflags,
160 struct vm_area_struct *vma,
163 struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
167 clear_user_highpage(page, vaddr);
174 * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
175 * @vma: The VMA the page is to be allocated for
176 * @vaddr: The virtual address the page will be inserted into
178 * This function will allocate a page for a VMA that the caller knows will
179 * be able to migrate in the future using move_pages() or reclaimed
181 static inline struct page *
182 alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
185 return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
188 static inline void clear_highpage(struct page *page)
190 void *kaddr = kmap_atomic(page, KM_USER0);
192 kunmap_atomic(kaddr, KM_USER0);
195 static inline void zero_user_segments(struct page *page,
196 unsigned start1, unsigned end1,
197 unsigned start2, unsigned end2)
199 void *kaddr = kmap_atomic(page, KM_USER0);
201 BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
204 memset(kaddr + start1, 0, end1 - start1);
207 memset(kaddr + start2, 0, end2 - start2);
209 kunmap_atomic(kaddr, KM_USER0);
210 flush_dcache_page(page);
213 static inline void zero_user_segment(struct page *page,
214 unsigned start, unsigned end)
216 zero_user_segments(page, start, end, 0, 0);
219 static inline void zero_user(struct page *page,
220 unsigned start, unsigned size)
222 zero_user_segments(page, start, start + size, 0, 0);
225 static inline void __deprecated memclear_highpage_flush(struct page *page,
226 unsigned int offset, unsigned int size)
228 zero_user(page, offset, size);
231 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
233 static inline void copy_user_highpage(struct page *to, struct page *from,
234 unsigned long vaddr, struct vm_area_struct *vma)
238 vfrom = kmap_atomic(from, KM_USER0);
239 vto = kmap_atomic(to, KM_USER1);
240 copy_user_page(vto, vfrom, vaddr, to);
241 kunmap_atomic(vto, KM_USER1);
242 kunmap_atomic(vfrom, KM_USER0);
247 static inline void copy_highpage(struct page *to, struct page *from)
251 vfrom = kmap_atomic(from, KM_USER0);
252 vto = kmap_atomic(to, KM_USER1);
253 copy_page(vto, vfrom);
254 kunmap_atomic(vto, KM_USER1);
255 kunmap_atomic(vfrom, KM_USER0);
258 #endif /* _LINUX_HIGHMEM_H */