1 #ifndef _ASM_X86_CACHEFLUSH_H 2 #define _ASM_X86_CACHEFLUSH_H 3 4 /* Caches aren't brain-dead on the intel. */ 5 #include <asm-generic/cacheflush.h> 6 7 #ifdef CONFIG_X86_PAT 8 /* 9 * X86 PAT uses page flags WC and Uncached together to keep track of 10 * memory type of pages that have backing page struct. X86 PAT supports 3 11 * different memory types, _PAGE_CACHE_WB, _PAGE_CACHE_WC and 12 * _PAGE_CACHE_UC_MINUS and fourth state where page's memory type has not 13 * been changed from its default (value of -1 used to denote this). 14 * Note we do not support _PAGE_CACHE_UC here. 15 */ 16 17 #define _PGMT_DEFAULT 0 18 #define _PGMT_WC (1UL << PG_arch_1) 19 #define _PGMT_UC_MINUS (1UL << PG_uncached) 20 #define _PGMT_WB (1UL << PG_uncached | 1UL << PG_arch_1) 21 #define _PGMT_MASK (1UL << PG_uncached | 1UL << PG_arch_1) 22 #define _PGMT_CLEAR_MASK (~_PGMT_MASK) 23 24 static inline unsigned long get_page_memtype(struct page *pg) 25 { 26 unsigned long pg_flags = pg->flags & _PGMT_MASK; 27 28 if (pg_flags == _PGMT_DEFAULT) 29 return -1; 30 else if (pg_flags == _PGMT_WC) 31 return _PAGE_CACHE_WC; 32 else if (pg_flags == _PGMT_UC_MINUS) 33 return _PAGE_CACHE_UC_MINUS; 34 else 35 return _PAGE_CACHE_WB; 36 } 37 38 static inline void set_page_memtype(struct page *pg, unsigned long memtype) 39 { 40 unsigned long memtype_flags = _PGMT_DEFAULT; 41 unsigned long old_flags; 42 unsigned long new_flags; 43 44 switch (memtype) { 45 case _PAGE_CACHE_WC: 46 memtype_flags = _PGMT_WC; 47 break; 48 case _PAGE_CACHE_UC_MINUS: 49 memtype_flags = _PGMT_UC_MINUS; 50 break; 51 case _PAGE_CACHE_WB: 52 memtype_flags = _PGMT_WB; 53 break; 54 } 55 56 do { 57 old_flags = pg->flags; 58 new_flags = (old_flags & _PGMT_CLEAR_MASK) | memtype_flags; 59 } while (cmpxchg(&pg->flags, old_flags, new_flags) != old_flags); 60 } 61 #else 62 static inline unsigned long get_page_memtype(struct page *pg) { return -1; } 63 static inline void set_page_memtype(struct page *pg, unsigned long memtype) { } 64 #endif 65 66 /* 67 * The set_memory_* API can be used to change various attributes of a virtual 68 * address range. The attributes include: 69 * Cachability : UnCached, WriteCombining, WriteBack 70 * Executability : eXeutable, NoteXecutable 71 * Read/Write : ReadOnly, ReadWrite 72 * Presence : NotPresent 73 * 74 * Within a category, the attributes are mutually exclusive. 75 * 76 * The implementation of this API will take care of various aspects that 77 * are associated with changing such attributes, such as: 78 * - Flushing TLBs 79 * - Flushing CPU caches 80 * - Making sure aliases of the memory behind the mapping don't violate 81 * coherency rules as defined by the CPU in the system. 82 * 83 * What this API does not do: 84 * - Provide exclusion between various callers - including callers that 85 * operation on other mappings of the same physical page 86 * - Restore default attributes when a page is freed 87 * - Guarantee that mappings other than the requested one are 88 * in any state, other than that these do not violate rules for 89 * the CPU you have. Do not depend on any effects on other mappings, 90 * CPUs other than the one you have may have more relaxed rules. 91 * The caller is required to take care of these. 92 */ 93 94 int _set_memory_uc(unsigned long addr, int numpages); 95 int _set_memory_wc(unsigned long addr, int numpages); 96 int _set_memory_wb(unsigned long addr, int numpages); 97 int set_memory_uc(unsigned long addr, int numpages); 98 int set_memory_wc(unsigned long addr, int numpages); 99 int set_memory_wb(unsigned long addr, int numpages); 100 int set_memory_x(unsigned long addr, int numpages); 101 int set_memory_nx(unsigned long addr, int numpages); 102 int set_memory_ro(unsigned long addr, int numpages); 103 int set_memory_rw(unsigned long addr, int numpages); 104 int set_memory_np(unsigned long addr, int numpages); 105 int set_memory_4k(unsigned long addr, int numpages); 106 107 int set_memory_array_uc(unsigned long *addr, int addrinarray); 108 int set_memory_array_wc(unsigned long *addr, int addrinarray); 109 int set_memory_array_wb(unsigned long *addr, int addrinarray); 110 111 int set_pages_array_uc(struct page **pages, int addrinarray); 112 int set_pages_array_wc(struct page **pages, int addrinarray); 113 int set_pages_array_wb(struct page **pages, int addrinarray); 114 115 /* 116 * For legacy compatibility with the old APIs, a few functions 117 * are provided that work on a "struct page". 118 * These functions operate ONLY on the 1:1 kernel mapping of the 119 * memory that the struct page represents, and internally just 120 * call the set_memory_* function. See the description of the 121 * set_memory_* function for more details on conventions. 122 * 123 * These APIs should be considered *deprecated* and are likely going to 124 * be removed in the future. 125 * The reason for this is the implicit operation on the 1:1 mapping only, 126 * making this not a generally useful API. 127 * 128 * Specifically, many users of the old APIs had a virtual address, 129 * called virt_to_page() or vmalloc_to_page() on that address to 130 * get a struct page* that the old API required. 131 * To convert these cases, use set_memory_*() on the original 132 * virtual address, do not use these functions. 133 */ 134 135 int set_pages_uc(struct page *page, int numpages); 136 int set_pages_wb(struct page *page, int numpages); 137 int set_pages_x(struct page *page, int numpages); 138 int set_pages_nx(struct page *page, int numpages); 139 int set_pages_ro(struct page *page, int numpages); 140 int set_pages_rw(struct page *page, int numpages); 141 142 143 void clflush_cache_range(void *addr, unsigned int size); 144 145 #ifdef CONFIG_DEBUG_RODATA 146 void mark_rodata_ro(void); 147 extern const int rodata_test_data; 148 extern int kernel_set_to_readonly; 149 void set_kernel_text_rw(void); 150 void set_kernel_text_ro(void); 151 #else 152 static inline void set_kernel_text_rw(void) { } 153 static inline void set_kernel_text_ro(void) { } 154 #endif 155 156 #ifdef CONFIG_DEBUG_RODATA_TEST 157 int rodata_test(void); 158 #else 159 static inline int rodata_test(void) 160 { 161 return 0; 162 } 163 #endif 164 165 #endif /* _ASM_X86_CACHEFLUSH_H */ 166