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 11static 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 17static 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 */ 27unsigned int nr_free_highpages(void); 28extern unsigned long totalhigh_pages; 29 30void kmap_flush_unused(void); 31 32#else /* CONFIG_HIGHMEM */ 33 34static inline unsigned int nr_free_highpages(void) { return 0; } 35 36#define totalhigh_pages 0 37 38#ifndef ARCH_HAS_KMAP 39static 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 49static 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#define kmap_atomic_pfn_prot(x, y, z) ( \ 60 panic("Enable CONFIG_HIGHMEM to use kmap_atomic_pfn_prot!!!\n"), \ 61 NULL) 62 63#define kmap_flush_unused() do {} while(0) 64#endif 65 66#endif /* CONFIG_HIGHMEM */ 67 68/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ 69static inline void clear_user_highpage(struct page *page, unsigned long vaddr) 70{ 71 void *addr = kmap_atomic(page, KM_USER0); 72 clear_user_page(addr, vaddr, page); 73 kunmap_atomic(addr, KM_USER0); 74 /* Make sure this page is cleared on other CPU's too before using it */ 75 smp_wmb(); 76} 77 78#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE 79static inline struct page * 80alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) 81{ 82 struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); 83 84 if (page) 85 clear_user_highpage(page, vaddr); 86 87 return page; 88} 89#endif 90 91static inline void clear_highpage(struct page *page) 92{ 93 void *kaddr = kmap_atomic(page, KM_USER0); 94 clear_page(kaddr); 95 kunmap_atomic(kaddr, KM_USER0); 96} 97 98/* 99 * Same but also flushes aliased cache contents to RAM. 100 * 101 * This must be a macro because KM_USER0 and friends aren't defined if 102 * !CONFIG_HIGHMEM 103 */ 104#define zero_user_page(page, offset, size, km_type) \ 105 do { \ 106 void *kaddr; \ 107 \ 108 BUG_ON((offset) + (size) > PAGE_SIZE); \ 109 \ 110 kaddr = kmap_atomic(page, km_type); \ 111 memset((char *)kaddr + (offset), 0, (size)); \ 112 flush_dcache_page(page); \ 113 kunmap_atomic(kaddr, (km_type)); \ 114 } while (0) 115 116static inline void __deprecated memclear_highpage_flush(struct page *page, 117 unsigned int offset, unsigned int size) 118{ 119 zero_user_page(page, offset, size, KM_USER0); 120} 121 122#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE 123 124static inline void copy_user_highpage(struct page *to, struct page *from, 125 unsigned long vaddr, struct vm_area_struct *vma) 126{ 127 char *vfrom, *vto; 128 129 vfrom = kmap_atomic(from, KM_USER0); 130 vto = kmap_atomic(to, KM_USER1); 131 copy_user_page(vto, vfrom, vaddr, to); 132 kunmap_atomic(vfrom, KM_USER0); 133 kunmap_atomic(vto, KM_USER1); 134 /* Make sure this page is cleared on other CPU's too before using it */ 135 smp_wmb(); 136} 137 138#endif 139 140static inline void copy_highpage(struct page *to, struct page *from) 141{ 142 char *vfrom, *vto; 143 144 vfrom = kmap_atomic(from, KM_USER0); 145 vto = kmap_atomic(to, KM_USER1); 146 copy_page(vto, vfrom); 147 kunmap_atomic(vfrom, KM_USER0); 148 kunmap_atomic(vto, KM_USER1); 149} 150 151#endif /* _LINUX_HIGHMEM_H */ 152