projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 1965aae3 PA |
1 | #ifndef _ASM_X86_PVCLOCK_H |
| 2 | #define _ASM_X86_PVCLOCK_H | |
| 7af192c9 GH |
3 | |
| 4 | #include <linux/clocksource.h> | |
| 5 | #include <asm/pvclock-abi.h> | |
| 6 | ||
| 7 | /* some helper functions for xen and kvm pv clock sources */ | |
| 8 | cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); | |
| 2697902b | 9 | u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src); |
| 424c32f1 | 10 | void pvclock_set_flags(u8 flags); |
| 3807f345 | 11 | unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); |
| 7af192c9 GH |
12 | void pvclock_read_wallclock(struct pvclock_wall_clock *wall, |
| 13 | struct pvclock_vcpu_time_info *vcpu, | |
| 14 | struct timespec *ts); | |
| e7a3481c | 15 | void pvclock_resume(void); |
| 7af192c9 | 16 | |
| 347bb444 ZA |
17 | /* |
| 18 | * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, | |
| 19 | * yielding a 64-bit result. | |
| 20 | */ | |
| 21 | static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) | |
| 22 | { | |
| 23 | u64 product; | |
| 24 | #ifdef __i386__ | |
| 25 | u32 tmp1, tmp2; | |
| de2d1a52 ZA |
26 | #else |
| 27 | ulong tmp; | |
| 347bb444 ZA |
28 | #endif |
| 29 | ||
| 30 | if (shift < 0) | |
| 31 | delta >>= -shift; | |
| 32 | else | |
| 33 | delta <<= shift; | |
| 34 | ||
| 35 | #ifdef __i386__ | |
| 36 | __asm__ ( | |
| 37 | "mul %5 ; " | |
| 38 | "mov %4,%%eax ; " | |
| 39 | "mov %%edx,%4 ; " | |
| 40 | "mul %5 ; " | |
| 41 | "xor %5,%5 ; " | |
| 42 | "add %4,%%eax ; " | |
| 43 | "adc %5,%%edx ; " | |
| 44 | : "=A" (product), "=r" (tmp1), "=r" (tmp2) | |
| 45 | : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); | |
| 46 | #elif defined(__x86_64__) | |
| 47 | __asm__ ( | |
| 3b217116 | 48 | "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]" |
| de2d1a52 ZA |
49 | : [lo]"=a"(product), |
| 50 | [hi]"=d"(tmp) | |
| 51 | : "0"(delta), | |
| 52 | [mul_frac]"rm"((u64)mul_frac)); | |
| 347bb444 ZA |
53 | #else |
| 54 | #error implement me! | |
| 55 | #endif | |
| 56 | ||
| 57 | return product; | |
| 58 | } | |
| 59 | ||
| dce2db0a MT |
60 | static __always_inline |
| 61 | u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src) | |
| 62 | { | |
| 63 | u64 delta = __native_read_tsc() - src->tsc_timestamp; | |
| 64 | return pvclock_scale_delta(delta, src->tsc_to_system_mul, | |
| 65 | src->tsc_shift); | |
| 66 | } | |
| 67 | ||
| 68 | static __always_inline | |
| 69 | unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, | |
| 70 | cycle_t *cycles, u8 *flags) | |
| 71 | { | |
| 72 | unsigned version; | |
| 73 | cycle_t ret, offset; | |
| 74 | u8 ret_flags; | |
| 75 | ||
| 76 | version = src->version; | |
| 77 | rdtsc_barrier(); | |
| 78 | offset = pvclock_get_nsec_offset(src); | |
| 79 | ret = src->system_time + offset; | |
| 80 | ret_flags = src->flags; | |
| 81 | rdtsc_barrier(); | |
| 82 | ||
| 83 | *cycles = ret; | |
| 84 | *flags = ret_flags; | |
| 85 | return version; | |
| 86 | } | |
| 87 | ||
| 1965aae3 | 88 | #endif /* _ASM_X86_PVCLOCK_H */ |