include/asm-x86/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 %0,%0\n"
  56                      "1:\n\t"
  57                      ".section .fixup,\"ax\"\n\t"
  58                      "3:  mov %3,%0 ; jmp 1b\n\t"
  59                      ".previous\n\t"
  60                      _ASM_EXTABLE(2b, 3b)
  61                      : "=r" (*err), EAX_EDX_RET(val, low, high)
  62                      : "c" (msr), "i" (-EFAULT));
  63         return EAX_EDX_VAL(val, low, high);
  64 }
  65
  66 static inline void native_write_msr(unsigned int msr,
  67                                     unsigned low, unsigned high)
  68 {
  69         asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory");
  70 }
  71
  72 static inline int native_write_msr_safe(unsigned int msr,
  73                                         unsigned low, unsigned high)
  74 {
  75         int err;
  76         asm volatile("2: wrmsr ; xor %0,%0\n"
  77                      "1:\n\t"
  78                      ".section .fixup,\"ax\"\n\t"
  79                      "3:  mov %4,%0 ; jmp 1b\n\t"
  80                      ".previous\n\t"
  81                      _ASM_EXTABLE(2b, 3b)
  82                      : "=a" (err)
  83                      : "c" (msr), "0" (low), "d" (high),
  84                        "i" (-EFAULT)
  85                      : "memory");
  86         return err;
  87 }
  88
  89 extern unsigned long long native_read_tsc(void);
  90
  91 static __always_inline unsigned long long __native_read_tsc(void)
  92 {
  93         DECLARE_ARGS(val, low, high);
  94
  95         rdtsc_barrier();
  96         asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
  97         rdtsc_barrier();
  98
  99         return EAX_EDX_VAL(val, low, high);
 100 }
 101
 102 static inline unsigned long long native_read_pmc(int counter)
 103 {
 104         DECLARE_ARGS(val, low, high);
 105
 106         asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
 107         return EAX_EDX_VAL(val, low, high);
 108 }
 109
 110 #ifdef CONFIG_PARAVIRT
 111 #include <asm/paravirt.h>
 112 #else
 113 #include <linux/errno.h>
 114 /*
 115  * Access to machine-specific registers (available on 586 and better only)
 116  * Note: the rd* operations modify the parameters directly (without using
 117  * pointer indirection), this allows gcc to optimize better
 118  */
 119
 120 #define rdmsr(msr, val1, val2)                                  \
 121 do {                                                            \
 122         u64 __val = native_read_msr((msr));                     \
 123         (val1) = (u32)__val;                                    \
 124         (val2) = (u32)(__val >> 32);                            \
 125 } while (0)
 126
 127 static inline void wrmsr(unsigned msr, unsigned low, unsigned high)
 128 {
 129         native_write_msr(msr, low, high);
 130 }
 131
 132 #define rdmsrl(msr, val)                        \
 133         ((val) = native_read_msr((msr)))
 134
 135 #define wrmsrl(msr, val)                                                \
 136         native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32))
 137
 138 /* wrmsr with exception handling */
 139 static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
 140 {
 141         return native_write_msr_safe(msr, low, high);
 142 }
 143
 144 /* rdmsr with exception handling */
 145 #define rdmsr_safe(msr, p1, p2)                                 \
 146 ({                                                              \
 147         int __err;                                              \
 148         u64 __val = native_read_msr_safe((msr), &__err);        \
 149         (*p1) = (u32)__val;                                     \
 150         (*p2) = (u32)(__val >> 32);                             \
 151         __err;                                                  \
 152 })
 153
 154 static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
 155 {
 156         int err;
 157
 158         *p = native_read_msr_safe(msr, &err);
 159         return err;
 160 }
 161
 162 #define rdtscl(low)                                             \
 163         ((low) = (u32)native_read_tsc())
 164
 165 #define rdtscll(val)                                            \
 166         ((val) = native_read_tsc())
 167
 168 #define rdpmc(counter, low, high)                       \
 169 do {                                                    \
 170         u64 _l = native_read_pmc((counter));            \
 171         (low)  = (u32)_l;                               \
 172         (high) = (u32)(_l >> 32);                       \
 173 } while (0)
 174
 175 #define rdtscp(low, high, aux)                                  \
 176 do {                                                            \
 177         unsigned long long _val = native_read_tscp(&(aux));     \
 178         (low) = (u32)_val;                                      \
 179         (high) = (u32)(_val >> 32);                             \
 180 } while (0)
 181
 182 #define rdtscpll(val, aux) (val) = native_read_tscp(&(aux))
 183
 184 #endif  /* !CONFIG_PARAVIRT */
 185
 186
 187 #define checking_wrmsrl(msr, val) wrmsr_safe((msr), (u32)(val),         \
 188                                              (u32)((val) >> 32))
 189
 190 #define write_tsc(val1, val2) wrmsr(0x10, (val1), (val2))
 191
 192 #define write_rdtscp_aux(val) wrmsr(0xc0000103, (val), 0)
 193
 194 #ifdef CONFIG_SMP
 195 void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 196 void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 197 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 198
 199 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 200 #else  /*  CONFIG_SMP  */
 201 static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
 202 {
 203         rdmsr(msr_no, *l, *h);
 204 }
 205 static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 206 {
 207         wrmsr(msr_no, l, h);
 208 }
 209 static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
 210                                     u32 *l, u32 *h)
 211 {
 212         return rdmsr_safe(msr_no, l, h);
 213 }
 214 static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 215 {
 216         return wrmsr_safe(msr_no, l, h);
 217 }
 218 #endif  /* CONFIG_SMP */
 219 #endif /* __ASSEMBLY__ */
 220 #endif /* __KERNEL__ */
 221
 222
 223 #endif