arch/x86/include/asm/msr.h

   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
  12 struct msr {
  13         union {
  14                 struct {
  15                         u32 l;
  16                         u32 h;
  17                 };
  18                 u64 q;
  19         };
  20 };
  21
  22 struct msr_info {
  23         u32 msr_no;
  24         struct msr reg;
  25         struct msr *msrs;
  26         int err;
  27 };
  28
  29 struct msr_regs_info {
  30         u32 *regs;
  31         int err;
  32 };
  33
  34 static 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
  60 static 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
  68 static 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
  84 static 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 */
  91 notrace 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
 108 extern unsigned long long native_read_tsc(void);
 109
 110 extern int rdmsr_safe_regs(u32 regs[8]);
 111 extern int wrmsr_safe_regs(u32 regs[8]);
 112
 113 static __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
 122 static 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)                                   \
 141 do {                                                            \
 142         u64 __val = native_read_msr((msr));                     \
 143         (void)((low) = (u32)__val);                             \
 144         (void)((high) = (u32)(__val >> 32));                    \
 145 } while (0)
 146
 147 static 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 */
 159 static 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
 174 static 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)                       \
 189 do {                                                    \
 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)                                  \
 198 do {                                                            \
 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
 215 struct msr *msrs_alloc(void);
 216 void msrs_free(struct msr *msrs);
 217
 218 #ifdef CONFIG_SMP
 219 int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 220 int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 221 void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
 222 void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
 223 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 224 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 225 int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
 226 int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
 227 #else  /*  CONFIG_SMP  */
 228 static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
 229 {
 230         rdmsr(msr_no, *l, *h);
 231         return 0;
 232 }
 233 static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 234 {
 235         wrmsr(msr_no, l, h);
 236         return 0;
 237 }
 238 static inline void rdmsr_on_cpus(const struct cpumask *m, u32 msr_no,
 239                                 struct msr *msrs)
 240 {
 241        rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h));
 242 }
 243 static inline void wrmsr_on_cpus(const struct cpumask *m, u32 msr_no,
 244                                 struct msr *msrs)
 245 {
 246        wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h);
 247 }
 248 static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
 249                                     u32 *l, u32 *h)
 250 {
 251         return rdmsr_safe(msr_no, l, h);
 252 }
 253 static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 254 {
 255         return wrmsr_safe(msr_no, l, h);
 256 }
 257 static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
 258 {
 259         return rdmsr_safe_regs(regs);
 260 }
 261 static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
 262 {
 263         return wrmsr_safe_regs(regs);
 264 }
 265 #endif  /* CONFIG_SMP */
 266 #endif /* __ASSEMBLY__ */
 267 #endif /* _ASM_X86_MSR_H */