arch/x86/include/asm/msr.h

   1 #ifndef _ASM_X86_MSR_H
   2 #define _ASM_X86_MSR_H
   3
   4 #include <asm/msr-index.h>
   5
   6 #ifndef __ASSEMBLY__
   7 # include <linux/types.h>
   8 #endif
   9
  10 #ifdef __KERNEL__
  11 #ifndef __ASSEMBLY__
  12
  13 #include <asm/asm.h>
  14 #include <asm/errno.h>
  15
  16 static inline unsigned long long native_read_tscp(unsigned int *aux)
  17 {
  18         unsigned long low, high;
  19         asm volatile(".byte 0x0f,0x01,0xf9"
  20                      : "=a" (low), "=d" (high), "=c" (*aux));
  21         return low | ((u64)high << 32);
  22 }
  23
  24 /*
  25  * i386 calling convention returns 64-bit value in edx:eax, while
  26  * x86_64 returns at rax. Also, the "A" constraint does not really
  27  * mean rdx:rax in x86_64, so we need specialized behaviour for each
  28  * architecture
  29  */
  30 #ifdef CONFIG_X86_64
  31 #define DECLARE_ARGS(val, low, high)    unsigned low, high
  32 #define EAX_EDX_VAL(val, low, high)     ((low) | ((u64)(high) << 32))
  33 #define EAX_EDX_ARGS(val, low, high)    "a" (low), "d" (high)
  34 #define EAX_EDX_RET(val, low, high)     "=a" (low), "=d" (high)
  35 #else
  36 #define DECLARE_ARGS(val, low, high)    unsigned long long val
  37 #define EAX_EDX_VAL(val, low, high)     (val)
  38 #define EAX_EDX_ARGS(val, low, high)    "A" (val)
  39 #define EAX_EDX_RET(val, low, high)     "=A" (val)
  40 #endif
  41
  42 static inline unsigned long long native_read_msr(unsigned int msr)
  43 {
  44         DECLARE_ARGS(val, low, high);
  45
  46         asm volatile("rdmsr" : EAX_EDX_RET(val, low, high) : "c" (msr));
  47         return EAX_EDX_VAL(val, low, high);
  48 }
  49
  50 static inline unsigned long long native_read_msr_safe(unsigned int msr,
  51                                                       int *err)
  52 {
  53         DECLARE_ARGS(val, low, high);
  54
  55         asm volatile("2: rdmsr ; xor %[err],%[err]\n"
  56                      "1:\n\t"
  57                      ".section .fixup,\"ax\"\n\t"
  58                      "3:  mov %[fault],%[err] ; jmp 1b\n\t"
  59                      ".previous\n\t"
  60                      _ASM_EXTABLE(2b, 3b)
  61                      : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
  62                      : "c" (msr), [fault] "i" (-EFAULT));
  63         return EAX_EDX_VAL(val, low, high);
  64 }
  65
  66 static inline unsigned long long native_read_msr_amd_safe(unsigned int msr,
  67                                                       int *err)
  68 {
  69         DECLARE_ARGS(val, low, high);
  70
  71         asm volatile("2: rdmsr ; xor %0,%0\n"
  72                      "1:\n\t"
  73                      ".section .fixup,\"ax\"\n\t"
  74                      "3:  mov %3,%0 ; jmp 1b\n\t"
  75                      ".previous\n\t"
  76                      _ASM_EXTABLE(2b, 3b)
  77                      : "=r" (*err), EAX_EDX_RET(val, low, high)
  78                      : "c" (msr), "D" (0x9c5a203a), "i" (-EFAULT));
  79         return EAX_EDX_VAL(val, low, high);
  80 }
  81
  82 static inline void native_write_msr(unsigned int msr,
  83                                     unsigned low, unsigned high)
  84 {
  85         asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory");
  86 }
  87
  88 static inline int native_write_msr_safe(unsigned int msr,
  89                                         unsigned low, unsigned high)
  90 {
  91         int err;
  92         asm volatile("2: wrmsr ; xor %[err],%[err]\n"
  93                      "1:\n\t"
  94                      ".section .fixup,\"ax\"\n\t"
  95                      "3:  mov %[fault],%[err] ; jmp 1b\n\t"
  96                      ".previous\n\t"
  97                      _ASM_EXTABLE(2b, 3b)
  98                      : [err] "=a" (err)
  99                      : "c" (msr), "0" (low), "d" (high),
 100                        [fault] "i" (-EFAULT)
 101                      : "memory");
 102         return err;
 103 }
 104
 105 extern unsigned long long native_read_tsc(void);
 106
 107 static __always_inline unsigned long long __native_read_tsc(void)
 108 {
 109         DECLARE_ARGS(val, low, high);
 110
 111         asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
 112
 113         return EAX_EDX_VAL(val, low, high);
 114 }
 115
 116 static inline unsigned long long native_read_pmc(int counter)
 117 {
 118         DECLARE_ARGS(val, low, high);
 119
 120         asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
 121         return EAX_EDX_VAL(val, low, high);
 122 }
 123
 124 #ifdef CONFIG_PARAVIRT
 125 #include <asm/paravirt.h>
 126 #else
 127 #include <linux/errno.h>
 128 /*
 129  * Access to machine-specific registers (available on 586 and better only)
 130  * Note: the rd* operations modify the parameters directly (without using
 131  * pointer indirection), this allows gcc to optimize better
 132  */
 133
 134 #define rdmsr(msr, val1, val2)                                  \
 135 do {                                                            \
 136         u64 __val = native_read_msr((msr));                     \
 137         (val1) = (u32)__val;                                    \
 138         (val2) = (u32)(__val >> 32);                            \
 139 } while (0)
 140
 141 static inline void wrmsr(unsigned msr, unsigned low, unsigned high)
 142 {
 143         native_write_msr(msr, low, high);
 144 }
 145
 146 #define rdmsrl(msr, val)                        \
 147         ((val) = native_read_msr((msr)))
 148
 149 #define wrmsrl(msr, val)                                                \
 150         native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32))
 151
 152 /* wrmsr with exception handling */
 153 static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
 154 {
 155         return native_write_msr_safe(msr, low, high);
 156 }
 157
 158 /* rdmsr with exception handling */
 159 #define rdmsr_safe(msr, p1, p2)                                 \
 160 ({                                                              \
 161         int __err;                                              \
 162         u64 __val = native_read_msr_safe((msr), &__err);        \
 163         (*p1) = (u32)__val;                                     \
 164         (*p2) = (u32)(__val >> 32);                             \
 165         __err;                                                  \
 166 })
 167
 168 static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
 169 {
 170         int err;
 171
 172         *p = native_read_msr_safe(msr, &err);
 173         return err;
 174 }
 175 static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
 176 {
 177         int err;
 178
 179         *p = native_read_msr_amd_safe(msr, &err);
 180         return err;
 181 }
 182
 183 #define rdtscl(low)                                             \
 184         ((low) = (u32)native_read_tsc())
 185
 186 #define rdtscll(val)                                            \
 187         ((val) = native_read_tsc())
 188
 189 #define rdpmc(counter, low, high)                       \
 190 do {                                                    \
 191         u64 _l = native_read_pmc((counter));            \
 192         (low)  = (u32)_l;                               \
 193         (high) = (u32)(_l >> 32);                       \
 194 } while (0)
 195
 196 #define rdtscp(low, high, aux)                                  \
 197 do {                                                            \
 198         unsigned long long _val = native_read_tscp(&(aux));     \
 199         (low) = (u32)_val;                                      \
 200         (high) = (u32)(_val >> 32);                             \
 201 } while (0)
 202
 203 #define rdtscpll(val, aux) (val) = native_read_tscp(&(aux))
 204
 205 #endif  /* !CONFIG_PARAVIRT */
 206
 207
 208 #define checking_wrmsrl(msr, val) wrmsr_safe((msr), (u32)(val),         \
 209                                              (u32)((val) >> 32))
 210
 211 #define write_tsc(val1, val2) wrmsr(0x10, (val1), (val2))
 212
 213 #define write_rdtscp_aux(val) wrmsr(0xc0000103, (val), 0)
 214
 215 #ifdef CONFIG_SMP
 216 int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 217 int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 218 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 219 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 220 #else  /*  CONFIG_SMP  */
 221 static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
 222 {
 223         rdmsr(msr_no, *l, *h);
 224         return 0;
 225 }
 226 static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 227 {
 228         wrmsr(msr_no, l, h);
 229         return 0;
 230 }
 231 static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
 232                                     u32 *l, u32 *h)
 233 {
 234         return rdmsr_safe(msr_no, l, h);
 235 }
 236 static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 237 {
 238         return wrmsr_safe(msr_no, l, h);
 239 }
 240 #endif  /* CONFIG_SMP */
 241 #endif /* __ASSEMBLY__ */
 242 #endif /* __KERNEL__ */
 243
 244
 245 #endif /* _ASM_X86_MSR_H */