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 <uapi/asm/msr.h>
   5
   6#ifndef __ASSEMBLY__
   7
   8#include <asm/asm.h>
   9#include <asm/errno.h>
  10#include <asm/cpumask.h>
  11
  12struct msr {
  13        union {
  14                struct {
  15                        u32 l;
  16                        u32 h;
  17                };
  18                u64 q;
  19        };
  20};
  21
  22struct msr_info {
  23        u32 msr_no;
  24        struct msr reg;
  25        struct msr *msrs;
  26        int err;
  27};
  28
  29struct msr_regs_info {
  30        u32 *regs;
  31        int err;
  32};
  33
  34static inline unsigned long long native_read_tscp(unsigned int *aux)
  35{
  36        unsigned long low, high;
  37        asm volatile(".byte 0x0f,0x01,0xf9"
  38                     : "=a" (low), "=d" (high), "=c" (*aux));
  39        return low | ((u64)high << 32);
  40}
  41
  42/*
  43 * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
  44 * constraint has different meanings. For i386, "A" means exactly
  45 * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead,
  46 * it means rax *or* rdx.
  47 */
  48#ifdef CONFIG_X86_64
  49#define DECLARE_ARGS(val, low, high)    unsigned low, high
  50#define EAX_EDX_VAL(val, low, high)     ((low) | ((u64)(high) << 32))
  51#define EAX_EDX_ARGS(val, low, high)    "a" (low), "d" (high)
  52#define EAX_EDX_RET(val, low, high)     "=a" (low), "=d" (high)
  53#else
  54#define DECLARE_ARGS(val, low, high)    unsigned long long val
  55#define EAX_EDX_VAL(val, low, high)     (val)
  56#define EAX_EDX_ARGS(val, low, high)    "A" (val)
  57#define EAX_EDX_RET(val, low, high)     "=A" (val)
  58#endif
  59
  60static inline unsigned long long native_read_msr(unsigned int msr)
  61{
  62        DECLARE_ARGS(val, low, high);
  63
  64        asm volatile("rdmsr" : EAX_EDX_RET(val, low, high) : "c" (msr));
  65        return EAX_EDX_VAL(val, low, high);
  66}
  67
  68static inline unsigned long long native_read_msr_safe(unsigned int msr,
  69                                                      int *err)
  70{
  71        DECLARE_ARGS(val, low, high);
  72
  73        asm volatile("2: rdmsr ; xor %[err],%[err]\n"
  74                     "1:\n\t"
  75                     ".section .fixup,\"ax\"\n\t"
  76                     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
  77                     ".previous\n\t"
  78                     _ASM_EXTABLE(2b, 3b)
  79                     : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
  80                     : "c" (msr), [fault] "i" (-EIO));
  81        return EAX_EDX_VAL(val, low, high);
  82}
  83
  84static inline void native_write_msr(unsigned int msr,
  85                                    unsigned low, unsigned high)
  86{
  87        asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory");
  88}
  89
  90/* Can be uninlined because referenced by paravirt */
  91notrace static inline int native_write_msr_safe(unsigned int msr,
  92                                        unsigned low, unsigned high)
  93{
  94        int err;
  95        asm volatile("2: wrmsr ; xor %[err],%[err]\n"
  96                     "1:\n\t"
  97                     ".section .fixup,\"ax\"\n\t"
  98                     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
  99                     ".previous\n\t"
 100                     _ASM_EXTABLE(2b, 3b)
 101                     : [err] "=a" (err)
 102                     : "c" (msr), "0" (low), "d" (high),
 103                       [fault] "i" (-EIO)
 104                     : "memory");
 105        return err;
 106}
 107
 108extern unsigned long long native_read_tsc(void);
 109
 110extern int rdmsr_safe_regs(u32 regs[8]);
 111extern int wrmsr_safe_regs(u32 regs[8]);
 112
 113static __always_inline unsigned long long __native_read_tsc(void)
 114{
 115        DECLARE_ARGS(val, low, high);
 116
 117        asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
 118
 119        return EAX_EDX_VAL(val, low, high);
 120}
 121
 122static inline unsigned long long native_read_pmc(int counter)
 123{
 124        DECLARE_ARGS(val, low, high);
 125
 126        asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
 127        return EAX_EDX_VAL(val, low, high);
 128}
 129
 130#ifdef CONFIG_PARAVIRT
 131#include <asm/paravirt.h>
 132#else
 133#include <linux/errno.h>
 134/*
 135 * Access to machine-specific registers (available on 586 and better only)
 136 * Note: the rd* operations modify the parameters directly (without using
 137 * pointer indirection), this allows gcc to optimize better
 138 */
 139
 140#define rdmsr(msr, low, high)                                   \
 141do {                                                            \
 142        u64 __val = native_read_msr((msr));                     \
 143        (void)((low) = (u32)__val);                             \
 144        (void)((high) = (u32)(__val >> 32));                    \
 145} while (0)
 146
 147static inline void wrmsr(unsigned msr, unsigned low, unsigned high)
 148{
 149        native_write_msr(msr, low, high);
 150}
 151
 152#define rdmsrl(msr, val)                        \
 153        ((val) = native_read_msr((msr)))
 154
 155#define wrmsrl(msr, val)                                                \
 156        native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32))
 157
 158/* wrmsr with exception handling */
 159static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
 160{
 161        return native_write_msr_safe(msr, low, high);
 162}
 163
 164/* rdmsr with exception handling */
 165#define rdmsr_safe(msr, low, high)                              \
 166({                                                              \
 167        int __err;                                              \
 168        u64 __val = native_read_msr_safe((msr), &__err);        \
 169        (*low) = (u32)__val;                                    \
 170        (*high) = (u32)(__val >> 32);                           \
 171        __err;                                                  \
 172})
 173
 174static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
 175{
 176        int err;
 177
 178        *p = native_read_msr_safe(msr, &err);
 179        return err;
 180}
 181
 182#define rdtscl(low)                                             \
 183        ((low) = (u32)__native_read_tsc())
 184
 185#define rdtscll(val)                                            \
 186        ((val) = __native_read_tsc())
 187
 188#define rdpmc(counter, low, high)                       \
 189do {                                                    \
 190        u64 _l = native_read_pmc((counter));            \
 191        (low)  = (u32)_l;                               \
 192        (high) = (u32)(_l >> 32);                       \
 193} while (0)
 194
 195#define rdpmcl(counter, val) ((val) = native_read_pmc(counter))
 196
 197#define rdtscp(low, high, aux)                                  \
 198do {                                                            \
 199        unsigned long long _val = native_read_tscp(&(aux));     \
 200        (low) = (u32)_val;                                      \
 201        (high) = (u32)(_val >> 32);                             \
 202} while (0)
 203
 204#define rdtscpll(val, aux) (val) = native_read_tscp(&(aux))
 205
 206#endif  /* !CONFIG_PARAVIRT */
 207
 208#define wrmsrl_safe(msr, val) wrmsr_safe((msr), (u32)(val),             \
 209                                             (u32)((val) >> 32))
 210
 211#define write_tsc(low, high) wrmsr(MSR_IA32_TSC, (low), (high))
 212
 213#define write_rdtscp_aux(val) wrmsr(MSR_TSC_AUX, (val), 0)
 214
 215struct msr *msrs_alloc(void);
 216void msrs_free(struct msr *msrs);
 217int msr_set_bit(u32 msr, u8 bit);
 218int msr_clear_bit(u32 msr, u8 bit);
 219
 220#ifdef CONFIG_SMP
 221int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 222int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 223int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
 224int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
 225void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
 226void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
 227int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 228int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 229int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
 230int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
 231int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
 232int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
 233#else  /*  CONFIG_SMP  */
 234static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
 235{
 236        rdmsr(msr_no, *l, *h);
 237        return 0;
 238}
 239static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 240{
 241        wrmsr(msr_no, l, h);
 242        return 0;
 243}
 244static inline int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
 245{
 246        rdmsrl(msr_no, *q);
 247        return 0;
 248}
 249static inline int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
 250{
 251        wrmsrl(msr_no, q);
 252        return 0;
 253}
 254static inline void rdmsr_on_cpus(const struct cpumask *m, u32 msr_no,
 255                                struct msr *msrs)
 256{
 257       rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h));
 258}
 259static inline void wrmsr_on_cpus(const struct cpumask *m, u32 msr_no,
 260                                struct msr *msrs)
 261{
 262       wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h);
 263}
 264static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
 265                                    u32 *l, u32 *h)
 266{
 267        return rdmsr_safe(msr_no, l, h);
 268}
 269static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 270{
 271        return wrmsr_safe(msr_no, l, h);
 272}
 273static inline int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
 274{
 275        return rdmsrl_safe(msr_no, q);
 276}
 277static inline int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
 278{
 279        return wrmsrl_safe(msr_no, q);
 280}
 281static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
 282{
 283        return rdmsr_safe_regs(regs);
 284}
 285static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
 286{
 287        return wrmsr_safe_regs(regs);
 288}
 289#endif  /* CONFIG_SMP */
 290#endif /* __ASSEMBLY__ */
 291#endif /* _ASM_X86_MSR_H */
 292