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 #include <asm/uaccess.h> 8 9 /* 10 * The set_memory_* API can be used to change various attributes of a virtual 11 * address range. The attributes include: 12 * Cachability : UnCached, WriteCombining, WriteThrough, WriteBack 13 * Executability : eXeutable, NoteXecutable 14 * Read/Write : ReadOnly, ReadWrite 15 * Presence : NotPresent 16 * 17 * Within a category, the attributes are mutually exclusive. 18 * 19 * The implementation of this API will take care of various aspects that 20 * are associated with changing such attributes, such as: 21 * - Flushing TLBs 22 * - Flushing CPU caches 23 * - Making sure aliases of the memory behind the mapping don't violate 24 * coherency rules as defined by the CPU in the system. 25 * 26 * What this API does not do: 27 * - Provide exclusion between various callers - including callers that 28 * operation on other mappings of the same physical page 29 * - Restore default attributes when a page is freed 30 * - Guarantee that mappings other than the requested one are 31 * in any state, other than that these do not violate rules for 32 * the CPU you have. Do not depend on any effects on other mappings, 33 * CPUs other than the one you have may have more relaxed rules. 34 * The caller is required to take care of these. 35 */ 36 37 int _set_memory_uc(unsigned long addr, int numpages); 38 int _set_memory_wc(unsigned long addr, int numpages); 39 int _set_memory_wt(unsigned long addr, int numpages); 40 int _set_memory_wb(unsigned long addr, int numpages); 41 int set_memory_uc(unsigned long addr, int numpages); 42 int set_memory_wc(unsigned long addr, int numpages); 43 int set_memory_wt(unsigned long addr, int numpages); 44 int set_memory_wb(unsigned long addr, int numpages); 45 int set_memory_x(unsigned long addr, int numpages); 46 int set_memory_nx(unsigned long addr, int numpages); 47 int set_memory_ro(unsigned long addr, int numpages); 48 int set_memory_rw(unsigned long addr, int numpages); 49 int set_memory_np(unsigned long addr, int numpages); 50 int set_memory_4k(unsigned long addr, int numpages); 51 52 int set_memory_array_uc(unsigned long *addr, int addrinarray); 53 int set_memory_array_wc(unsigned long *addr, int addrinarray); 54 int set_memory_array_wt(unsigned long *addr, int addrinarray); 55 int set_memory_array_wb(unsigned long *addr, int addrinarray); 56 57 int set_pages_array_uc(struct page **pages, int addrinarray); 58 int set_pages_array_wc(struct page **pages, int addrinarray); 59 int set_pages_array_wt(struct page **pages, int addrinarray); 60 int set_pages_array_wb(struct page **pages, int addrinarray); 61 62 /* 63 * For legacy compatibility with the old APIs, a few functions 64 * are provided that work on a "struct page". 65 * These functions operate ONLY on the 1:1 kernel mapping of the 66 * memory that the struct page represents, and internally just 67 * call the set_memory_* function. See the description of the 68 * set_memory_* function for more details on conventions. 69 * 70 * These APIs should be considered *deprecated* and are likely going to 71 * be removed in the future. 72 * The reason for this is the implicit operation on the 1:1 mapping only, 73 * making this not a generally useful API. 74 * 75 * Specifically, many users of the old APIs had a virtual address, 76 * called virt_to_page() or vmalloc_to_page() on that address to 77 * get a struct page* that the old API required. 78 * To convert these cases, use set_memory_*() on the original 79 * virtual address, do not use these functions. 80 */ 81 82 int set_pages_uc(struct page *page, int numpages); 83 int set_pages_wb(struct page *page, int numpages); 84 int set_pages_x(struct page *page, int numpages); 85 int set_pages_nx(struct page *page, int numpages); 86 int set_pages_ro(struct page *page, int numpages); 87 int set_pages_rw(struct page *page, int numpages); 88 89 90 void clflush_cache_range(void *addr, unsigned int size); 91 92 #ifdef CONFIG_DEBUG_RODATA 93 void mark_rodata_ro(void); 94 extern const int rodata_test_data; 95 extern int kernel_set_to_readonly; 96 void set_kernel_text_rw(void); 97 void set_kernel_text_ro(void); 98 #else 99 static inline void set_kernel_text_rw(void) { } 100 static inline void set_kernel_text_ro(void) { } 101 #endif 102 103 #ifdef CONFIG_DEBUG_RODATA_TEST 104 int rodata_test(void); 105 #else 106 static inline int rodata_test(void) 107 { 108 return 0; 109 } 110 #endif 111 112 #ifdef ARCH_HAS_NOCACHE_UACCESS 113 114 /** 115 * arch_memcpy_to_pmem - copy data to persistent memory 116 * @dst: destination buffer for the copy 117 * @src: source buffer for the copy 118 * @n: length of the copy in bytes 119 * 120 * Copy data to persistent memory media via non-temporal stores so that 121 * a subsequent arch_wmb_pmem() can flush cpu and memory controller 122 * write buffers to guarantee durability. 123 */ 124 static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src, 125 size_t n) 126 { 127 int unwritten; 128 129 /* 130 * We are copying between two kernel buffers, if 131 * __copy_from_user_inatomic_nocache() returns an error (page 132 * fault) we would have already reported a general protection fault 133 * before the WARN+BUG. 134 */ 135 unwritten = __copy_from_user_inatomic_nocache((void __force *) dst, 136 (void __user *) src, n); 137 if (WARN(unwritten, "%s: fault copying %p <- %p unwritten: %d\n", 138 __func__, dst, src, unwritten)) 139 BUG(); 140 } 141 142 /** 143 * arch_wmb_pmem - synchronize writes to persistent memory 144 * 145 * After a series of arch_memcpy_to_pmem() operations this drains data 146 * from cpu write buffers and any platform (memory controller) buffers 147 * to ensure that written data is durable on persistent memory media. 148 */ 149 static inline void arch_wmb_pmem(void) 150 { 151 /* 152 * wmb() to 'sfence' all previous writes such that they are 153 * architecturally visible to 'pcommit'. Note, that we've 154 * already arranged for pmem writes to avoid the cache via 155 * arch_memcpy_to_pmem(). 156 */ 157 wmb(); 158 pcommit_sfence(); 159 } 160 161 static inline bool __arch_has_wmb_pmem(void) 162 { 163 #ifdef CONFIG_X86_64 164 /* 165 * We require that wmb() be an 'sfence', that is only guaranteed on 166 * 64-bit builds 167 */ 168 return static_cpu_has(X86_FEATURE_PCOMMIT); 169 #else 170 return false; 171 #endif 172 } 173 #else /* ARCH_HAS_NOCACHE_UACCESS i.e. ARCH=um */ 174 extern void arch_memcpy_to_pmem(void __pmem *dst, const void *src, size_t n); 175 extern void arch_wmb_pmem(void); 176 177 static inline bool __arch_has_wmb_pmem(void) 178 { 179 return false; 180 } 181 #endif 182 183 #endif /* _ASM_X86_CACHEFLUSH_H */ 184