#ifndef _ASM_X86_MSR_H #define _ASM_X86_MSR_H #include "msr-index.h" #ifndef __ASSEMBLY__ #include #include #include #include struct msr { union { struct { u32 l; u32 h; }; u64 q; }; }; struct msr_info { u32 msr_no; struct msr reg; struct msr *msrs; int err; }; struct msr_regs_info { u32 *regs; int err; }; static inline unsigned long long native_read_tscp(unsigned int *aux) { unsigned long low, high; asm volatile(".byte 0x0f,0x01,0xf9" : "=a" (low), "=d" (high), "=c" (*aux)); return low | ((u64)high << 32); } /* * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A" * constraint has different meanings. For i386, "A" means exactly * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead, * it means rax *or* rdx. */ #ifdef CONFIG_X86_64 /* Using 64-bit values saves one instruction clearing the high half of low */ #define DECLARE_ARGS(val, low, high) unsigned long low, high #define EAX_EDX_VAL(val, low, high) ((low) | (high) << 32) #define EAX_EDX_RET(val, low, high) "=a" (low), "=d" (high) #else #define DECLARE_ARGS(val, low, high) unsigned long long val #define EAX_EDX_VAL(val, low, high) (val) #define EAX_EDX_RET(val, low, high) "=A" (val) #endif static inline unsigned long long native_read_msr(unsigned int msr) { DECLARE_ARGS(val, low, high); asm volatile("rdmsr" : EAX_EDX_RET(val, low, high) : "c" (msr)); return EAX_EDX_VAL(val, low, high); } static inline unsigned long long native_read_msr_safe(unsigned int msr, int *err) { DECLARE_ARGS(val, low, high); asm volatile("2: rdmsr ; xor %[err],%[err]\n" "1:\n\t" ".section .fixup,\"ax\"\n\t" "3: mov %[fault],%[err] ; jmp 1b\n\t" ".previous\n\t" _ASM_EXTABLE(2b, 3b) : [err] "=r" (*err), EAX_EDX_RET(val, low, high) : "c" (msr), [fault] "i" (-EIO)); return EAX_EDX_VAL(val, low, high); } static inline void native_write_msr(unsigned int msr, unsigned low, unsigned high) { asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory"); } /* Can be uninlined because referenced by paravirt */ notrace static inline int native_write_msr_safe(unsigned int msr, unsigned low, unsigned high) { int err; asm volatile("2: wrmsr ; xor %[err],%[err]\n" "1:\n\t" ".section .fixup,\"ax\"\n\t" "3: mov %[fault],%[err] ; jmp 1b\n\t" ".previous\n\t" _ASM_EXTABLE(2b, 3b) : [err] "=a" (err) : "c" (msr), "0" (low), "d" (high), [fault] "i" (-EIO) : "memory"); return err; } extern int rdmsr_safe_regs(u32 regs[8]); extern int wrmsr_safe_regs(u32 regs[8]); /** * rdtsc() - returns the current TSC without ordering constraints * * rdtsc() returns the result of RDTSC as a 64-bit integer. The * only ordering constraint it supplies is the ordering implied by * "asm volatile": it will put the RDTSC in the place you expect. The * CPU can and will speculatively execute that RDTSC, though, so the * results can be non-monotonic if compared on different CPUs. */ static __always_inline unsigned long long rdtsc(void) { DECLARE_ARGS(val, low, high); asm volatile("rdtsc" : EAX_EDX_RET(val, low, high)); return EAX_EDX_VAL(val, low, high); } /** * rdtsc_ordered() - read the current TSC in program order * * rdtsc_ordered() returns the result of RDTSC as a 64-bit integer. * It is ordered like a load to a global in-memory counter. It should * be impossible to observe non-monotonic rdtsc_unordered() behavior * across multiple CPUs as long as the TSC is synced. */ static __always_inline unsigned long long rdtsc_ordered(void) { /* * The RDTSC instruction is not ordered relative to memory * access. The Intel SDM and the AMD APM are both vague on this * point, but empirically an RDTSC instruction can be * speculatively executed before prior loads. An RDTSC * immediately after an appropriate barrier appears to be * ordered as a normal load, that is, it provides the same * ordering guarantees as reading from a global memory location * that some other imaginary CPU is updating continuously with a * time stamp. */ alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, "lfence", X86_FEATURE_LFENCE_RDTSC); return rdtsc(); } static inline unsigned long long native_read_pmc(int counter) { DECLARE_ARGS(val, low, high); asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter)); return EAX_EDX_VAL(val, low, high); } #ifdef CONFIG_PARAVIRT #include #else #include /* * Access to machine-specific registers (available on 586 and better only) * Note: the rd* operations modify the parameters directly (without using * pointer indirection), this allows gcc to optimize better */ #define rdmsr(msr, low, high) \ do { \ u64 __val = native_read_msr((msr)); \ (void)((low) = (u32)__val); \ (void)((high) = (u32)(__val >> 32)); \ } while (0) static inline void wrmsr(unsigned msr, unsigned low, unsigned high) { native_write_msr(msr, low, high); } #define rdmsrl(msr, val) \ ((val) = native_read_msr((msr))) #define wrmsrl(msr, val) \ native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32)) /* wrmsr with exception handling */ static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high) { return native_write_msr_safe(msr, low, high); } /* rdmsr with exception handling */ #define rdmsr_safe(msr, low, high) \ ({ \ int __err; \ u64 __val = native_read_msr_safe((msr), &__err); \ (*low) = (u32)__val; \ (*high) = (u32)(__val >> 32); \ __err; \ }) static inline int rdmsrl_safe(unsigned msr, unsigned long long *p) { int err; *p = native_read_msr_safe(msr, &err); return err; } #define rdpmc(counter, low, high) \ do { \ u64 _l = native_read_pmc((counter)); \ (low) = (u32)_l; \ (high) = (u32)(_l >> 32); \ } while (0) #define rdpmcl(counter, val) ((val) = native_read_pmc(counter)) #endif /* !CONFIG_PARAVIRT */ /* * 64-bit version of wrmsr_safe(): */ static inline int wrmsrl_safe(u32 msr, u64 val) { return wrmsr_safe(msr, (u32)val, (u32)(val >> 32)); } #define write_tsc(low, high) wrmsr(MSR_IA32_TSC, (low), (high)) #define write_rdtscp_aux(val) wrmsr(MSR_TSC_AUX, (val), 0) struct msr *msrs_alloc(void); void msrs_free(struct msr *msrs); int msr_set_bit(u32 msr, u8 bit); int msr_clear_bit(u32 msr, u8 bit); #ifdef CONFIG_SMP int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h); int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h); int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q); int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q); void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs); void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs); int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h); int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h); int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q); int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q); int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]); int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]); #else /* CONFIG_SMP */ static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) { rdmsr(msr_no, *l, *h); return 0; } static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) { wrmsr(msr_no, l, h); return 0; } static inline int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q) { rdmsrl(msr_no, *q); return 0; } static inline int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q) { wrmsrl(msr_no, q); return 0; } static inline void rdmsr_on_cpus(const struct cpumask *m, u32 msr_no, struct msr *msrs) { rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h)); } static inline void wrmsr_on_cpus(const struct cpumask *m, u32 msr_no, struct msr *msrs) { wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h); } static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) { return rdmsr_safe(msr_no, l, h); } static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) { return wrmsr_safe(msr_no, l, h); } static inline int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q) { return rdmsrl_safe(msr_no, q); } static inline int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q) { return wrmsrl_safe(msr_no, q); } static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]) { return rdmsr_safe_regs(regs); } static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]) { return wrmsr_safe_regs(regs); } #endif /* CONFIG_SMP */ #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_MSR_H */