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
   8#include <linux/types.h>
   9#include <linux/ioctl.h>
  10
  11#define X86_IOC_RDMSR_REGS      _IOWR('c', 0xA0, __u32[8])
  12#define X86_IOC_WRMSR_REGS      _IOWR('c', 0xA1, __u32[8])
  13
  14#ifdef __KERNEL__
  15
  16#include <asm/asm.h>
  17#include <asm/errno.h>
  18#include <asm/cpumask.h>
  19
  20struct msr {
  21        union {
  22                struct {
  23                        u32 l;
  24                        u32 h;
  25                };
  26                u64 q;
  27        };
  28};
  29
  30static inline unsigned long long native_read_tscp(unsigned int *aux)
  31{
  32        unsigned long low, high;
  33        asm volatile(".byte 0x0f,0x01,0xf9"
  34                     : "=a" (low), "=d" (high), "=c" (*aux));
  35        return low | ((u64)high << 32);
  36}
  37
  38/*
  39 * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
  40 * constraint has different meanings. For i386, "A" means exactly
  41 * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead,
  42 * it means rax *or* rdx.
  43 */
  44#ifdef CONFIG_X86_64
  45#define DECLARE_ARGS(val, low, high)    unsigned low, high
  46#define EAX_EDX_VAL(val, low, high)     ((low) | ((u64)(high) << 32))
  47#define EAX_EDX_ARGS(val, low, high)    "a" (low), "d" (high)
  48#define EAX_EDX_RET(val, low, high)     "=a" (low), "=d" (high)
  49#else
  50#define DECLARE_ARGS(val, low, high)    unsigned long long val
  51#define EAX_EDX_VAL(val, low, high)     (val)
  52#define EAX_EDX_ARGS(val, low, high)    "A" (val)
  53#define EAX_EDX_RET(val, low, high)     "=A" (val)
  54#endif
  55
  56static inline unsigned long long native_read_msr(unsigned int msr)
  57{
  58        DECLARE_ARGS(val, low, high);
  59
  60        asm volatile("rdmsr" : EAX_EDX_RET(val, low, high) : "c" (msr));
  61        return EAX_EDX_VAL(val, low, high);
  62}
  63
  64static inline unsigned long long native_read_msr_safe(unsigned int msr,
  65                                                      int *err)
  66{
  67        DECLARE_ARGS(val, low, high);
  68
  69        asm volatile("2: rdmsr ; xor %[err],%[err]\n"
  70                     "1:\n\t"
  71                     ".section .fixup,\"ax\"\n\t"
  72                     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
  73                     ".previous\n\t"
  74                     _ASM_EXTABLE(2b, 3b)
  75                     : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
  76                     : "c" (msr), [fault] "i" (-EIO));
  77        return EAX_EDX_VAL(val, low, high);
  78}
  79
  80static inline void native_write_msr(unsigned int msr,
  81                                    unsigned low, unsigned high)
  82{
  83        asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory");
  84}
  85
  86/* Can be uninlined because referenced by paravirt */
  87notrace static inline int native_write_msr_safe(unsigned int msr,
  88                                        unsigned low, unsigned high)
  89{
  90        int err;
  91        asm volatile("2: wrmsr ; xor %[err],%[err]\n"
  92                     "1:\n\t"
  93                     ".section .fixup,\"ax\"\n\t"
  94                     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
  95                     ".previous\n\t"
  96                     _ASM_EXTABLE(2b, 3b)
  97                     : [err] "=a" (err)
  98                     : "c" (msr), "0" (low), "d" (high),
  99                       [fault] "i" (-EIO)
 100                     : "memory");
 101        return err;
 102}
 103
 104extern unsigned long long native_read_tsc(void);
 105
 106extern int native_rdmsr_safe_regs(u32 regs[8]);
 107extern int native_wrmsr_safe_regs(u32 regs[8]);
 108
 109static __always_inline unsigned long long __native_read_tsc(void)
 110{
 111        DECLARE_ARGS(val, low, high);
 112
 113        asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
 114
 115        return EAX_EDX_VAL(val, low, high);
 116}
 117
 118static inline unsigned long long native_read_pmc(int counter)
 119{
 120        DECLARE_ARGS(val, low, high);
 121
 122        asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
 123        return EAX_EDX_VAL(val, low, high);
 124}
 125
 126#ifdef CONFIG_PARAVIRT
 127#include <asm/paravirt.h>
 128#else
 129#include <linux/errno.h>
 130/*
 131 * Access to machine-specific registers (available on 586 and better only)
 132 * Note: the rd* operations modify the parameters directly (without using
 133 * pointer indirection), this allows gcc to optimize better
 134 */
 135
 136#define rdmsr(msr, val1, val2)                                  \
 137do {                                                            \
 138        u64 __val = native_read_msr((msr));                     \
 139        (val1) = (u32)__val;                                    \
 140        (val2) = (u32)(__val >> 32);                            \
 141} while (0)
 142
 143static inline void wrmsr(unsigned msr, unsigned low, unsigned high)
 144{
 145        native_write_msr(msr, low, high);
 146}
 147
 148#define rdmsrl(msr, val)                        \
 149        ((val) = native_read_msr((msr)))
 150
 151#define wrmsrl(msr, val)                                                \
 152        native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32))
 153
 154/* wrmsr with exception handling */
 155static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
 156{
 157        return native_write_msr_safe(msr, low, high);
 158}
 159
 160/* rdmsr with exception handling */
 161#define rdmsr_safe(msr, p1, p2)                                 \
 162({                                                              \
 163        int __err;                                              \
 164        u64 __val = native_read_msr_safe((msr), &__err);        \
 165        (*p1) = (u32)__val;                                     \
 166        (*p2) = (u32)(__val >> 32);                             \
 167        __err;                                                  \
 168})
 169
 170static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
 171{
 172        int err;
 173
 174        *p = native_read_msr_safe(msr, &err);
 175        return err;
 176}
 177
 178static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
 179{
 180        u32 gprs[8] = { 0 };
 181        int err;
 182
 183        gprs[1] = msr;
 184        gprs[7] = 0x9c5a203a;
 185
 186        err = native_rdmsr_safe_regs(gprs);
 187
 188        *p = gprs[0] | ((u64)gprs[2] << 32);
 189
 190        return err;
 191}
 192
 193static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
 194{
 195        u32 gprs[8] = { 0 };
 196
 197        gprs[0] = (u32)val;
 198        gprs[1] = msr;
 199        gprs[2] = val >> 32;
 200        gprs[7] = 0x9c5a203a;
 201
 202        return native_wrmsr_safe_regs(gprs);
 203}
 204
 205static inline int rdmsr_safe_regs(u32 regs[8])
 206{
 207        return native_rdmsr_safe_regs(regs);
 208}
 209
 210static inline int wrmsr_safe_regs(u32 regs[8])
 211{
 212        return native_wrmsr_safe_regs(regs);
 213}
 214
 215#define rdtscl(low)                                             \
 216        ((low) = (u32)__native_read_tsc())
 217
 218#define rdtscll(val)                                            \
 219        ((val) = __native_read_tsc())
 220
 221#define rdpmc(counter, low, high)                       \
 222do {                                                    \
 223        u64 _l = native_read_pmc((counter));            \
 224        (low)  = (u32)_l;                               \
 225        (high) = (u32)(_l >> 32);                       \
 226} while (0)
 227
 228#define rdtscp(low, high, aux)                                  \
 229do {                                                            \
 230        unsigned long long _val = native_read_tscp(&(aux));     \
 231        (low) = (u32)_val;                                      \
 232        (high) = (u32)(_val >> 32);                             \
 233} while (0)
 234
 235#define rdtscpll(val, aux) (val) = native_read_tscp(&(aux))
 236
 237#endif  /* !CONFIG_PARAVIRT */
 238
 239
 240#define checking_wrmsrl(msr, val) wrmsr_safe((msr), (u32)(val),         \
 241                                             (u32)((val) >> 32))
 242
 243#define write_tsc(val1, val2) wrmsr(0x10, (val1), (val2))
 244
 245#define write_rdtscp_aux(val) wrmsr(0xc0000103, (val), 0)
 246
 247#ifdef CONFIG_SMP
 248int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 249int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 250void rdmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs);
 251void wrmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs);
 252int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 253int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 254int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
 255int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
 256#else  /*  CONFIG_SMP  */
 257static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
 258{
 259        rdmsr(msr_no, *l, *h);
 260        return 0;
 261}
 262static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 263{
 264        wrmsr(msr_no, l, h);
 265        return 0;
 266}
 267static inline void rdmsr_on_cpus(const cpumask_t *m, u32 msr_no,
 268                                struct msr *msrs)
 269{
 270       rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h));
 271}
 272static inline void wrmsr_on_cpus(const cpumask_t *m, u32 msr_no,
 273                                struct msr *msrs)
 274{
 275       wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h);
 276}
 277static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
 278                                    u32 *l, u32 *h)
 279{
 280        return rdmsr_safe(msr_no, l, h);
 281}
 282static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 283{
 284        return wrmsr_safe(msr_no, l, h);
 285}
 286static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
 287{
 288        return rdmsr_safe_regs(regs);
 289}
 290static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
 291{
 292        return wrmsr_safe_regs(regs);
 293}
 294#endif  /* CONFIG_SMP */
 295#endif /* __KERNEL__ */
 296#endif /* __ASSEMBLY__ */
 297#endif /* _ASM_X86_MSR_H */
 298