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 #endif 21 22 #ifdef CONFIG_HIGHMEM 23 24 #include <asm/highmem.h> 25 26 /* declarations for linux/mm/highmem.c */ 27 unsigned int nr_free_highpages(void); 28 extern unsigned long totalhigh_pages; 29 30 void kmap_flush_unused(void); 31 32 #else /* CONFIG_HIGHMEM */ 33 34 static inline unsigned int nr_free_highpages(void) { return 0; } 35 36 #define totalhigh_pages 0 37 38 #ifndef ARCH_HAS_KMAP 39 static inline void *kmap(struct page *page) 40 { 41 might_sleep(); 42 return page_address(page); 43 } 44 45 #define kunmap(page) do { (void) (page); } while (0) 46 47 #include <asm/kmap_types.h> 48 49 static inline void *kmap_atomic(struct page *page, enum km_type idx) 50 { 51 pagefault_disable(); 52 return page_address(page); 53 } 54 #define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx) 55 56 #define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0) 57 #define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx)) 58 #define kmap_atomic_to_page(ptr) virt_to_page(ptr) 59 60 #define kmap_flush_unused() do {} while(0) 61 #endif 62 63 #endif /* CONFIG_HIGHMEM */ 64 65 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ 66 static inline void clear_user_highpage(struct page *page, unsigned long vaddr) 67 { 68 void *addr = kmap_atomic(page, KM_USER0); 69 clear_user_page(addr, vaddr, page); 70 kunmap_atomic(addr, KM_USER0); 71 /* Make sure this page is cleared on other CPU's too before using it */ 72 smp_wmb(); 73 } 74 75 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE 76 static inline struct page * 77 alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) 78 { 79 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); 80 81 if (page) 82 clear_user_highpage(page, vaddr); 83 84 return page; 85 } 86 #endif 87 88 static inline void clear_highpage(struct page *page) 89 { 90 void *kaddr = kmap_atomic(page, KM_USER0); 91 clear_page(kaddr); 92 kunmap_atomic(kaddr, KM_USER0); 93 } 94 95 /* 96 * Same but also flushes aliased cache contents to RAM. 97 * 98 * This must be a macro because KM_USER0 and friends aren't defined if 99 * !CONFIG_HIGHMEM 100 */ 101 #define zero_user_page(page, offset, size, km_type) \ 102 do { \ 103 void *kaddr; \ 104 \ 105 BUG_ON((offset) + (size) > PAGE_SIZE); \ 106 \ 107 kaddr = kmap_atomic(page, km_type); \ 108 memset((char *)kaddr + (offset), 0, (size)); \ 109 flush_dcache_page(page); \ 110 kunmap_atomic(kaddr, (km_type)); \ 111 } while (0) 112 113 static inline void __deprecated memclear_highpage_flush(struct page *page, 114 unsigned int offset, unsigned int size) 115 { 116 zero_user_page(page, offset, size, KM_USER0); 117 } 118 119 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE 120 121 static inline void copy_user_highpage(struct page *to, struct page *from, 122 unsigned long vaddr, struct vm_area_struct *vma) 123 { 124 char *vfrom, *vto; 125 126 vfrom = kmap_atomic(from, KM_USER0); 127 vto = kmap_atomic(to, KM_USER1); 128 copy_user_page(vto, vfrom, vaddr, to); 129 kunmap_atomic(vfrom, KM_USER0); 130 kunmap_atomic(vto, KM_USER1); 131 /* Make sure this page is cleared on other CPU's too before using it */ 132 smp_wmb(); 133 } 134 135 #endif 136 137 static inline void copy_highpage(struct page *to, struct page *from) 138 { 139 char *vfrom, *vto; 140 141 vfrom = kmap_atomic(from, KM_USER0); 142 vto = kmap_atomic(to, KM_USER1); 143 copy_page(vto, vfrom); 144 kunmap_atomic(vfrom, KM_USER0); 145 kunmap_atomic(vto, KM_USER1); 146 } 147 148 #endif /* _LINUX_HIGHMEM_H */ 149