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 #include <asm/special_insns.h> 7 8 #ifdef CONFIG_X86_PAT 9 /* 10 * X86 PAT uses page flags WC and Uncached together to keep track of 11 * memory type of pages that have backing page struct. X86 PAT supports 3 12 * different memory types, _PAGE_CACHE_WB, _PAGE_CACHE_WC and 13 * _PAGE_CACHE_UC_MINUS and fourth state where page's memory type has not 14 * been changed from its default (value of -1 used to denote this). 15 * Note we do not support _PAGE_CACHE_UC here. 16 */ 17 18 #define _PGMT_DEFAULT 0 19 #define _PGMT_WC (1UL << PG_arch_1) 20 #define _PGMT_UC_MINUS (1UL << PG_uncached) 21 #define _PGMT_WB (1UL << PG_uncached | 1UL << PG_arch_1) 22 #define _PGMT_MASK (1UL << PG_uncached | 1UL << PG_arch_1) 23 #define _PGMT_CLEAR_MASK (~_PGMT_MASK) 24 25 static inline unsigned long get_page_memtype(struct page *pg) 26 { 27 unsigned long pg_flags = pg->flags & _PGMT_MASK; 28 29 if (pg_flags == _PGMT_DEFAULT) 30 return -1; 31 else if (pg_flags == _PGMT_WC) 32 return _PAGE_CACHE_WC; 33 else if (pg_flags == _PGMT_UC_MINUS) 34 return _PAGE_CACHE_UC_MINUS; 35 else 36 return _PAGE_CACHE_WB; 37 } 38 39 static inline void set_page_memtype(struct page *pg, unsigned long memtype) 40 { 41 unsigned long memtype_flags = _PGMT_DEFAULT; 42 unsigned long old_flags; 43 unsigned long new_flags; 44 45 switch (memtype) { 46 case _PAGE_CACHE_WC: 47 memtype_flags = _PGMT_WC; 48 break; 49 case _PAGE_CACHE_UC_MINUS: 50 memtype_flags = _PGMT_UC_MINUS; 51 break; 52 case _PAGE_CACHE_WB: 53 memtype_flags = _PGMT_WB; 54 break; 55 } 56 57 do { 58 old_flags = pg->flags; 59 new_flags = (old_flags & _PGMT_CLEAR_MASK) | memtype_flags; 60 } while (cmpxchg(&pg->flags, old_flags, new_flags) != old_flags); 61 } 62 #else 63 static inline unsigned long get_page_memtype(struct page *pg) { return -1; } 64 static inline void set_page_memtype(struct page *pg, unsigned long memtype) { } 65 #endif 66 67 /* 68 * The set_memory_* API can be used to change various attributes of a virtual 69 * address range. The attributes include: 70 * Cachability : UnCached, WriteCombining, WriteBack 71 * Executability : eXeutable, NoteXecutable 72 * Read/Write : ReadOnly, ReadWrite 73 * Presence : NotPresent 74 * 75 * Within a category, the attributes are mutually exclusive. 76 * 77 * The implementation of this API will take care of various aspects that 78 * are associated with changing such attributes, such as: 79 * - Flushing TLBs 80 * - Flushing CPU caches 81 * - Making sure aliases of the memory behind the mapping don't violate 82 * coherency rules as defined by the CPU in the system. 83 * 84 * What this API does not do: 85 * - Provide exclusion between various callers - including callers that 86 * operation on other mappings of the same physical page 87 * - Restore default attributes when a page is freed 88 * - Guarantee that mappings other than the requested one are 89 * in any state, other than that these do not violate rules for 90 * the CPU you have. Do not depend on any effects on other mappings, 91 * CPUs other than the one you have may have more relaxed rules. 92 * The caller is required to take care of these. 93 */ 94 95 int _set_memory_uc(unsigned long addr, int numpages); 96 int _set_memory_wc(unsigned long addr, int numpages); 97 int _set_memory_wb(unsigned long addr, int numpages); 98 int set_memory_uc(unsigned long addr, int numpages); 99 int set_memory_wc(unsigned long addr, int numpages); 100 int set_memory_wb(unsigned long addr, int numpages); 101 int set_memory_x(unsigned long addr, int numpages); 102 int set_memory_nx(unsigned long addr, int numpages); 103 int set_memory_ro(unsigned long addr, int numpages); 104 int set_memory_rw(unsigned long addr, int numpages); 105 int set_memory_np(unsigned long addr, int numpages); 106 int set_memory_4k(unsigned long addr, int numpages); 107 108 int set_memory_array_uc(unsigned long *addr, int addrinarray); 109 int set_memory_array_wc(unsigned long *addr, int addrinarray); 110 int set_memory_array_wb(unsigned long *addr, int addrinarray); 111 112 int set_pages_array_uc(struct page **pages, int addrinarray); 113 int set_pages_array_wc(struct page **pages, int addrinarray); 114 int set_pages_array_wb(struct page **pages, int addrinarray); 115 116 /* 117 * For legacy compatibility with the old APIs, a few functions 118 * are provided that work on a "struct page". 119 * These functions operate ONLY on the 1:1 kernel mapping of the 120 * memory that the struct page represents, and internally just 121 * call the set_memory_* function. See the description of the 122 * set_memory_* function for more details on conventions. 123 * 124 * These APIs should be considered *deprecated* and are likely going to 125 * be removed in the future. 126 * The reason for this is the implicit operation on the 1:1 mapping only, 127 * making this not a generally useful API. 128 * 129 * Specifically, many users of the old APIs had a virtual address, 130 * called virt_to_page() or vmalloc_to_page() on that address to 131 * get a struct page* that the old API required. 132 * To convert these cases, use set_memory_*() on the original 133 * virtual address, do not use these functions. 134 */ 135 136 int set_pages_uc(struct page *page, int numpages); 137 int set_pages_wb(struct page *page, int numpages); 138 int set_pages_x(struct page *page, int numpages); 139 int set_pages_nx(struct page *page, int numpages); 140 int set_pages_ro(struct page *page, int numpages); 141 int set_pages_rw(struct page *page, int numpages); 142 143 144 void clflush_cache_range(void *addr, unsigned int size); 145 146 #ifdef CONFIG_DEBUG_RODATA 147 void mark_rodata_ro(void); 148 extern const int rodata_test_data; 149 extern int kernel_set_to_readonly; 150 void set_kernel_text_rw(void); 151 void set_kernel_text_ro(void); 152 #else 153 static inline void set_kernel_text_rw(void) { } 154 static inline void set_kernel_text_ro(void) { } 155 #endif 156 157 #ifdef CONFIG_DEBUG_RODATA_TEST 158 int rodata_test(void); 159 #else 160 static inline int rodata_test(void) 161 { 162 return 0; 163 } 164 #endif 165 166 #endif /* _ASM_X86_CACHEFLUSH_H */ 167