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
  30struct msr_info {
  31        u32 msr_no;
  32        struct msr reg;
  33        struct msr *msrs;
  34        int err;
  35};
  36
  37struct msr_regs_info {
  38        u32 *regs;
  39        int err;
  40};
  41
  42static inline unsigned long long native_read_tscp(unsigned int *aux)
  43{
  44        unsigned long low, high;
  45        asm volatile(".byte 0x0f,0x01,0xf9"
  46                     : "=a" (low), "=d" (high), "=c" (*aux));
  47        return low | ((u64)high << 32);
  48}
  49
  50/*
  51 * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
  52 * constraint has different meanings. For i386, "A" means exactly
  53 * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead,
  54 * it means rax *or* rdx.
  55 */
  56#ifdef CONFIG_X86_64
  57#define DECLARE_ARGS(val, low, high)    unsigned low, high
  58#define EAX_EDX_VAL(val, low, high)     ((low) | ((u64)(high) << 32))
  59#define EAX_EDX_ARGS(val, low, high)    "a" (low), "d" (high)
  60#define EAX_EDX_RET(val, low, high)     "=a" (low), "=d" (high)
  61#else
  62#define DECLARE_ARGS(val, low, high)    unsigned long long val
  63#define EAX_EDX_VAL(val, low, high)     (val)
  64#define EAX_EDX_ARGS(val, low, high)    "A" (val)
  65#define EAX_EDX_RET(val, low, high)     "=A" (val)
  66#endif
  67
  68static inline unsigned long long native_read_msr(unsigned int msr)
  69{
  70        DECLARE_ARGS(val, low, high);
  71
  72        asm volatile("rdmsr" : EAX_EDX_RET(val, low, high) : "c" (msr));
  73        return EAX_EDX_VAL(val, low, high);
  74}
  75
  76static inline unsigned long long native_read_msr_safe(unsigned int msr,
  77                                                      int *err)
  78{
  79        DECLARE_ARGS(val, low, high);
  80
  81        asm volatile("2: rdmsr ; xor %[err],%[err]\n"
  82                     "1:\n\t"
  83                     ".section .fixup,\"ax\"\n\t"
  84                     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
  85                     ".previous\n\t"
  86                     _ASM_EXTABLE(2b, 3b)
  87                     : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
  88                     : "c" (msr), [fault] "i" (-EIO));
  89        return EAX_EDX_VAL(val, low, high);
  90}
  91
  92static inline void native_write_msr(unsigned int msr,
  93                                    unsigned low, unsigned high)
  94{
  95        asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory");
  96}
  97
  98/* Can be uninlined because referenced by paravirt */
  99notrace static inline int native_write_msr_safe(unsigned int msr,
 100                                        unsigned low, unsigned high)
 101{
 102        int err;
 103        asm volatile("2: wrmsr ; xor %[err],%[err]\n"
 104                     "1:\n\t"
 105                     ".section .fixup,\"ax\"\n\t"
 106                     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
 107                     ".previous\n\t"
 108                     _ASM_EXTABLE(2b, 3b)
 109                     : [err] "=a" (err)
 110                     : "c" (msr), "0" (low), "d" (high),
 111                       [fault] "i" (-EIO)
 112                     : "memory");
 113        return err;
 114}
 115
 116extern unsigned long long native_read_tsc(void);
 117
 118extern int native_rdmsr_safe_regs(u32 regs[8]);
 119extern int native_wrmsr_safe_regs(u32 regs[8]);
 120
 121static __always_inline unsigned long long __native_read_tsc(void)
 122{
 123        DECLARE_ARGS(val, low, high);
 124
 125        asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
 126
 127        return EAX_EDX_VAL(val, low, high);
 128}
 129
 130static inline unsigned long long native_read_pmc(int counter)
 131{
 132        DECLARE_ARGS(val, low, high);
 133
 134        asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
 135        return EAX_EDX_VAL(val, low, high);
 136}
 137
 138#ifdef CONFIG_PARAVIRT
 139#include <asm/paravirt.h>
 140#else
 141#include <linux/errno.h>
 142/*
 143 * Access to machine-specific registers (available on 586 and better only)
 144 * Note: the rd* operations modify the parameters directly (without using
 145 * pointer indirection), this allows gcc to optimize better
 146 */
 147
 148#define rdmsr(msr, val1, val2)                                  \
 149do {                                                            \
 150        u64 __val = native_read_msr((msr));                     \
 151        (void)((val1) = (u32)__val);                            \
 152        (void)((val2) = (u32)(__val >> 32));                    \
 153} while (0)
 154
 155static inline void wrmsr(unsigned msr, unsigned low, unsigned high)
 156{
 157        native_write_msr(msr, low, high);
 158}
 159
 160#define rdmsrl(msr, val)                        \
 161        ((val) = native_read_msr((msr)))
 162
 163#define wrmsrl(msr, val)                                                \
 164        native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32))
 165
 166/* wrmsr with exception handling */
 167static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
 168{
 169        return native_write_msr_safe(msr, low, high);
 170}
 171
 172/* rdmsr with exception handling */
 173#define rdmsr_safe(msr, p1, p2)                                 \
 174({                                                              \
 175        int __err;                                              \
 176        u64 __val = native_read_msr_safe((msr), &__err);        \
 177        (*p1) = (u32)__val;                                     \
 178        (*p2) = (u32)(__val >> 32);                             \
 179        __err;                                                  \
 180})
 181
 182static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
 183{
 184        int err;
 185
 186        *p = native_read_msr_safe(msr, &err);
 187        return err;
 188}
 189
 190static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
 191{
 192        u32 gprs[8] = { 0 };
 193        int err;
 194
 195        gprs[1] = msr;
 196        gprs[7] = 0x9c5a203a;
 197
 198        err = native_rdmsr_safe_regs(gprs);
 199
 200        *p = gprs[0] | ((u64)gprs[2] << 32);
 201
 202        return err;
 203}
 204
 205static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
 206{
 207        u32 gprs[8] = { 0 };
 208
 209        gprs[0] = (u32)val;
 210        gprs[1] = msr;
 211        gprs[2] = val >> 32;
 212        gprs[7] = 0x9c5a203a;
 213
 214        return native_wrmsr_safe_regs(gprs);
 215}
 216
 217static inline int rdmsr_safe_regs(u32 regs[8])
 218{
 219        return native_rdmsr_safe_regs(regs);
 220}
 221
 222static inline int wrmsr_safe_regs(u32 regs[8])
 223{
 224        return native_wrmsr_safe_regs(regs);
 225}
 226
 227#define rdtscl(low)                                             \
 228        ((low) = (u32)__native_read_tsc())
 229
 230#define rdtscll(val)                                            \
 231        ((val) = __native_read_tsc())
 232
 233#define rdpmc(counter, low, high)                       \
 234do {                                                    \
 235        u64 _l = native_read_pmc((counter));            \
 236        (low)  = (u32)_l;                               \
 237        (high) = (u32)(_l >> 32);                       \
 238} while (0)
 239
 240#define rdtscp(low, high, aux)                                  \
 241do {                                                            \
 242        unsigned long long _val = native_read_tscp(&(aux));     \
 243        (low) = (u32)_val;                                      \
 244        (high) = (u32)(_val >> 32);                             \
 245} while (0)
 246
 247#define rdtscpll(val, aux) (val) = native_read_tscp(&(aux))
 248
 249#endif  /* !CONFIG_PARAVIRT */
 250
 251
 252#define checking_wrmsrl(msr, val) wrmsr_safe((msr), (u32)(val),         \
 253                                             (u32)((val) >> 32))
 254
 255#define write_tsc(val1, val2) wrmsr(MSR_IA32_TSC, (val1), (val2))
 256
 257#define write_rdtscp_aux(val) wrmsr(MSR_TSC_AUX, (val), 0)
 258
 259struct msr *msrs_alloc(void);
 260void msrs_free(struct msr *msrs);
 261
 262#ifdef CONFIG_SMP
 263int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 264int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 265void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
 266void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
 267int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 268int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 269int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
 270int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
 271#else  /*  CONFIG_SMP  */
 272static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
 273{
 274        rdmsr(msr_no, *l, *h);
 275        return 0;
 276}
 277static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 278{
 279        wrmsr(msr_no, l, h);
 280        return 0;
 281}
 282static inline void rdmsr_on_cpus(const struct cpumask *m, u32 msr_no,
 283                                struct msr *msrs)
 284{
 285       rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h));
 286}
 287static inline void wrmsr_on_cpus(const struct cpumask *m, u32 msr_no,
 288                                struct msr *msrs)
 289{
 290       wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h);
 291}
 292static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
 293                                    u32 *l, u32 *h)
 294{
 295        return rdmsr_safe(msr_no, l, h);
 296}
 297static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 298{
 299        return wrmsr_safe(msr_no, l, h);
 300}
 301static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
 302{
 303        return rdmsr_safe_regs(regs);
 304}
 305static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
 306{
 307        return wrmsr_safe_regs(regs);
 308}
 309#endif  /* CONFIG_SMP */
 310#endif /* __KERNEL__ */
 311#endif /* __ASSEMBLY__ */
 312#endif /* _ASM_X86_MSR_H */
 313