1 #ifndef _LINUX_HIGHMEM_H 2 #define _LINUX_HIGHMEM_H 3 4 #include <linux/config.h> 5 #include <linux/fs.h> 6 #include <linux/mm.h> 7 8 #include <asm/cacheflush.h> 9 10 #ifndef ARCH_HAS_FLUSH_ANON_PAGE 11 static inline void flush_anon_page(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 29 #else /* CONFIG_HIGHMEM */ 30 31 static inline unsigned int nr_free_highpages(void) { return 0; } 32 33 static inline void *kmap(struct page *page) 34 { 35 might_sleep(); 36 return page_address(page); 37 } 38 39 #define kunmap(page) do { (void) (page); } while (0) 40 41 #define kmap_atomic(page, idx) page_address(page) 42 #define kunmap_atomic(addr, idx) do { } while (0) 43 #define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn)) 44 #define kmap_atomic_to_page(ptr) virt_to_page(ptr) 45 46 #endif /* CONFIG_HIGHMEM */ 47 48 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ 49 static inline void clear_user_highpage(struct page *page, unsigned long vaddr) 50 { 51 void *addr = kmap_atomic(page, KM_USER0); 52 clear_user_page(addr, vaddr, page); 53 kunmap_atomic(addr, KM_USER0); 54 /* Make sure this page is cleared on other CPU's too before using it */ 55 smp_wmb(); 56 } 57 58 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE 59 static inline struct page * 60 alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) 61 { 62 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); 63 64 if (page) 65 clear_user_highpage(page, vaddr); 66 67 return page; 68 } 69 #endif 70 71 static inline void clear_highpage(struct page *page) 72 { 73 void *kaddr = kmap_atomic(page, KM_USER0); 74 clear_page(kaddr); 75 kunmap_atomic(kaddr, KM_USER0); 76 } 77 78 /* 79 * Same but also flushes aliased cache contents to RAM. 80 */ 81 static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size) 82 { 83 void *kaddr; 84 85 BUG_ON(offset + size > PAGE_SIZE); 86 87 kaddr = kmap_atomic(page, KM_USER0); 88 memset((char *)kaddr + offset, 0, size); 89 flush_dcache_page(page); 90 kunmap_atomic(kaddr, KM_USER0); 91 } 92 93 static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr) 94 { 95 char *vfrom, *vto; 96 97 vfrom = kmap_atomic(from, KM_USER0); 98 vto = kmap_atomic(to, KM_USER1); 99 copy_user_page(vto, vfrom, vaddr, to); 100 kunmap_atomic(vfrom, KM_USER0); 101 kunmap_atomic(vto, KM_USER1); 102 /* Make sure this page is cleared on other CPU's too before using it */ 103 smp_wmb(); 104 } 105 106 static inline void copy_highpage(struct page *to, struct page *from) 107 { 108 char *vfrom, *vto; 109 110 vfrom = kmap_atomic(from, KM_USER0); 111 vto = kmap_atomic(to, KM_USER1); 112 copy_page(vto, vfrom); 113 kunmap_atomic(vfrom, KM_USER0); 114 kunmap_atomic(vto, KM_USER1); 115 } 116 117 #endif /* _LINUX_HIGHMEM_H */ 118