linux/arch/x86/include/asm/msr.h
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   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
  16static 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
  42static 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
  50static 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
  66static 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
  82static 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
  88static 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
 105extern unsigned long long native_read_tsc(void);
 106
 107static __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
 116static 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)                                  \
 135do {                                                            \
 136        u64 __val = native_read_msr((msr));                     \
 137        (val1) = (u32)__val;                                    \
 138        (val2) = (u32)(__val >> 32);                            \
 139} while (0)
 140
 141static 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 */
 153static 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
 168static 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}
 175static 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)                       \
 190do {                                                    \
 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)                                  \
 197do {                                                            \
 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
 216int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 217int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 218int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 219int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 220#else  /*  CONFIG_SMP  */
 221static 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}
 226static 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}
 231static 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}
 236static 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 */
 246
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