1 #ifndef _ASM_X86_PVCLOCK_H
2 #define _ASM_X86_PVCLOCK_H
4 #include <linux/clocksource.h>
5 #include <asm/pvclock-abi.h>
7 #ifdef CONFIG_KVM_GUEST
8 extern struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void);
10 static inline struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void)
16 /* some helper functions for xen and kvm pv clock sources */
17 cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
18 u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
19 void pvclock_set_flags(u8 flags);
20 unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
21 void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
22 struct pvclock_vcpu_time_info *vcpu,
24 void pvclock_resume(void);
26 void pvclock_touch_watchdogs(void);
28 static __always_inline
29 unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src)
31 unsigned version = src->version & ~1;
32 /* Make sure that the version is read before the data. */
37 static __always_inline
38 bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src,
41 /* Make sure that the version is re-read after the data. */
43 return unlikely(version != src->version);
47 * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
48 * yielding a 64-bit result.
50 static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
73 : "=A" (product), "=r" (tmp1), "=r" (tmp2)
74 : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
75 #elif defined(__x86_64__)
77 "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
81 [mul_frac]"rm"((u64)mul_frac));
89 static __always_inline
90 cycle_t __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
93 u64 delta = tsc - src->tsc_timestamp;
94 cycle_t offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
96 return src->system_time + offset;
99 struct pvclock_vsyscall_time_info {
100 struct pvclock_vcpu_time_info pvti;
101 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
103 #define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
105 #endif /* _ASM_X86_PVCLOCK_H */