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 #ifdef CONFIG_HIGHMEM 11 12 #include <asm/highmem.h> 13 14 /* declarations for linux/mm/highmem.c */ 15 unsigned int nr_free_highpages(void); 16 17 #else /* CONFIG_HIGHMEM */ 18 19 static inline unsigned int nr_free_highpages(void) { return 0; } 20 21 static inline void *kmap(struct page *page) 22 { 23 might_sleep(); 24 return page_address(page); 25 } 26 27 #define kunmap(page) do { (void) (page); } while (0) 28 29 #define kmap_atomic(page, idx) page_address(page) 30 #define kunmap_atomic(addr, idx) do { } while (0) 31 #define kmap_atomic_to_page(ptr) virt_to_page(ptr) 32 33 #endif /* CONFIG_HIGHMEM */ 34 35 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ 36 static inline void clear_user_highpage(struct page *page, unsigned long vaddr) 37 { 38 void *addr = kmap_atomic(page, KM_USER0); 39 clear_user_page(addr, vaddr, page); 40 kunmap_atomic(addr, KM_USER0); 41 /* Make sure this page is cleared on other CPU's too before using it */ 42 smp_wmb(); 43 } 44 45 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE 46 static inline struct page * 47 alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) 48 { 49 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); 50 51 if (page) 52 clear_user_highpage(page, vaddr); 53 54 return page; 55 } 56 #endif 57 58 static inline void clear_highpage(struct page *page) 59 { 60 void *kaddr = kmap_atomic(page, KM_USER0); 61 clear_page(kaddr); 62 kunmap_atomic(kaddr, KM_USER0); 63 } 64 65 /* 66 * Same but also flushes aliased cache contents to RAM. 67 */ 68 static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size) 69 { 70 void *kaddr; 71 72 BUG_ON(offset + size > PAGE_SIZE); 73 74 kaddr = kmap_atomic(page, KM_USER0); 75 memset((char *)kaddr + offset, 0, size); 76 flush_dcache_page(page); 77 kunmap_atomic(kaddr, KM_USER0); 78 } 79 80 static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr) 81 { 82 char *vfrom, *vto; 83 84 vfrom = kmap_atomic(from, KM_USER0); 85 vto = kmap_atomic(to, KM_USER1); 86 copy_user_page(vto, vfrom, vaddr, to); 87 kunmap_atomic(vfrom, KM_USER0); 88 kunmap_atomic(vto, KM_USER1); 89 /* Make sure this page is cleared on other CPU's too before using it */ 90 smp_wmb(); 91 } 92 93 static inline void copy_highpage(struct page *to, struct page *from) 94 { 95 char *vfrom, *vto; 96 97 vfrom = kmap_atomic(from, KM_USER0); 98 vto = kmap_atomic(to, KM_USER1); 99 copy_page(vto, vfrom); 100 kunmap_atomic(vfrom, KM_USER0); 101 kunmap_atomic(vto, KM_USER1); 102 } 103 104 #endif /* _LINUX_HIGHMEM_H */ 105