1 #ifndef _ASM_X86_SPECIAL_INSNS_H 2 #define _ASM_X86_SPECIAL_INSNS_H 3 4 5 #ifdef __KERNEL__ 6 7 static inline void native_clts(void) 8 { 9 asm volatile("clts"); 10 } 11 12 /* 13 * Volatile isn't enough to prevent the compiler from reordering the 14 * read/write functions for the control registers and messing everything up. 15 * A memory clobber would solve the problem, but would prevent reordering of 16 * all loads stores around it, which can hurt performance. Solution is to 17 * use a variable and mimic reads and writes to it to enforce serialization 18 */ 19 extern unsigned long __force_order; 20 21 static inline unsigned long native_read_cr0(void) 22 { 23 unsigned long val; 24 asm volatile("mov %%cr0,%0\n\t" : "=r" (val), "=m" (__force_order)); 25 return val; 26 } 27 28 static inline void native_write_cr0(unsigned long val) 29 { 30 asm volatile("mov %0,%%cr0": : "r" (val), "m" (__force_order)); 31 } 32 33 static inline unsigned long native_read_cr2(void) 34 { 35 unsigned long val; 36 asm volatile("mov %%cr2,%0\n\t" : "=r" (val), "=m" (__force_order)); 37 return val; 38 } 39 40 static inline void native_write_cr2(unsigned long val) 41 { 42 asm volatile("mov %0,%%cr2": : "r" (val), "m" (__force_order)); 43 } 44 45 static inline unsigned long native_read_cr3(void) 46 { 47 unsigned long val; 48 asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order)); 49 return val; 50 } 51 52 static inline void native_write_cr3(unsigned long val) 53 { 54 asm volatile("mov %0,%%cr3": : "r" (val), "m" (__force_order)); 55 } 56 57 static inline unsigned long native_read_cr4(void) 58 { 59 unsigned long val; 60 asm volatile("mov %%cr4,%0\n\t" : "=r" (val), "=m" (__force_order)); 61 return val; 62 } 63 64 static inline unsigned long native_read_cr4_safe(void) 65 { 66 unsigned long val; 67 /* This could fault if %cr4 does not exist. In x86_64, a cr4 always 68 * exists, so it will never fail. */ 69 #ifdef CONFIG_X86_32 70 asm volatile("1: mov %%cr4, %0\n" 71 "2:\n" 72 _ASM_EXTABLE(1b, 2b) 73 : "=r" (val), "=m" (__force_order) : "0" (0)); 74 #else 75 val = native_read_cr4(); 76 #endif 77 return val; 78 } 79 80 static inline void native_write_cr4(unsigned long val) 81 { 82 asm volatile("mov %0,%%cr4": : "r" (val), "m" (__force_order)); 83 } 84 85 #ifdef CONFIG_X86_64 86 static inline unsigned long native_read_cr8(void) 87 { 88 unsigned long cr8; 89 asm volatile("movq %%cr8,%0" : "=r" (cr8)); 90 return cr8; 91 } 92 93 static inline void native_write_cr8(unsigned long val) 94 { 95 asm volatile("movq %0,%%cr8" :: "r" (val) : "memory"); 96 } 97 #endif 98 99 static inline void native_wbinvd(void) 100 { 101 asm volatile("wbinvd": : :"memory"); 102 } 103 104 extern asmlinkage void native_load_gs_index(unsigned); 105 106 #ifdef CONFIG_PARAVIRT 107 #include <asm/paravirt.h> 108 #else 109 110 static inline unsigned long read_cr0(void) 111 { 112 return native_read_cr0(); 113 } 114 115 static inline void write_cr0(unsigned long x) 116 { 117 native_write_cr0(x); 118 } 119 120 static inline unsigned long read_cr2(void) 121 { 122 return native_read_cr2(); 123 } 124 125 static inline void write_cr2(unsigned long x) 126 { 127 native_write_cr2(x); 128 } 129 130 static inline unsigned long read_cr3(void) 131 { 132 return native_read_cr3(); 133 } 134 135 static inline void write_cr3(unsigned long x) 136 { 137 native_write_cr3(x); 138 } 139 140 static inline unsigned long __read_cr4(void) 141 { 142 return native_read_cr4(); 143 } 144 145 static inline unsigned long __read_cr4_safe(void) 146 { 147 return native_read_cr4_safe(); 148 } 149 150 static inline void __write_cr4(unsigned long x) 151 { 152 native_write_cr4(x); 153 } 154 155 static inline void wbinvd(void) 156 { 157 native_wbinvd(); 158 } 159 160 #ifdef CONFIG_X86_64 161 162 static inline unsigned long read_cr8(void) 163 { 164 return native_read_cr8(); 165 } 166 167 static inline void write_cr8(unsigned long x) 168 { 169 native_write_cr8(x); 170 } 171 172 static inline void load_gs_index(unsigned selector) 173 { 174 native_load_gs_index(selector); 175 } 176 177 #endif 178 179 /* Clear the 'TS' bit */ 180 static inline void clts(void) 181 { 182 native_clts(); 183 } 184 185 #endif/* CONFIG_PARAVIRT */ 186 187 #define stts() write_cr0(read_cr0() | X86_CR0_TS) 188 189 static inline void clflush(volatile void *__p) 190 { 191 asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p)); 192 } 193 194 static inline void clflushopt(volatile void *__p) 195 { 196 alternative_io(".byte " __stringify(NOP_DS_PREFIX) "; clflush %P0", 197 ".byte 0x66; clflush %P0", 198 X86_FEATURE_CLFLUSHOPT, 199 "+m" (*(volatile char __force *)__p)); 200 } 201 202 #define nop() asm volatile ("nop") 203 204 205 #endif /* __KERNEL__ */ 206 207 #endif /* _ASM_X86_SPECIAL_INSNS_H */ 208