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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 | ||
8705d603 | 7 | #ifdef CONFIG_KVM_GUEST |
dac16fba AL |
8 | extern struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void); |
9 | #else | |
10 | static inline struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void) | |
11 | { | |
12 | return NULL; | |
13 | } | |
14 | #endif | |
15 | ||
7af192c9 | 16 | /* some helper functions for xen and kvm pv clock sources */ |
a5a1d1c2 | 17 | u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); |
2697902b | 18 | u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src); |
424c32f1 | 19 | void pvclock_set_flags(u8 flags); |
3807f345 | 20 | unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); |
7af192c9 GH |
21 | void pvclock_read_wallclock(struct pvclock_wall_clock *wall, |
22 | struct pvclock_vcpu_time_info *vcpu, | |
23 | struct timespec *ts); | |
e7a3481c | 24 | void pvclock_resume(void); |
7af192c9 | 25 | |
d63285e9 MT |
26 | void pvclock_touch_watchdogs(void); |
27 | ||
3aed64f6 PB |
28 | static __always_inline |
29 | unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src) | |
30 | { | |
31 | unsigned version = src->version & ~1; | |
32 | /* Make sure that the version is read before the data. */ | |
33 | virt_rmb(); | |
34 | return version; | |
35 | } | |
36 | ||
37 | static __always_inline | |
38 | bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src, | |
39 | unsigned version) | |
40 | { | |
41 | /* Make sure that the version is re-read after the data. */ | |
42 | virt_rmb(); | |
43 | return unlikely(version != src->version); | |
44 | } | |
45 | ||
347bb444 ZA |
46 | /* |
47 | * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, | |
48 | * yielding a 64-bit result. | |
49 | */ | |
50 | static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) | |
51 | { | |
52 | u64 product; | |
53 | #ifdef __i386__ | |
54 | u32 tmp1, tmp2; | |
de2d1a52 ZA |
55 | #else |
56 | ulong tmp; | |
347bb444 ZA |
57 | #endif |
58 | ||
59 | if (shift < 0) | |
60 | delta >>= -shift; | |
61 | else | |
62 | delta <<= shift; | |
63 | ||
64 | #ifdef __i386__ | |
65 | __asm__ ( | |
66 | "mul %5 ; " | |
67 | "mov %4,%%eax ; " | |
68 | "mov %%edx,%4 ; " | |
69 | "mul %5 ; " | |
70 | "xor %5,%5 ; " | |
71 | "add %4,%%eax ; " | |
72 | "adc %5,%%edx ; " | |
73 | : "=A" (product), "=r" (tmp1), "=r" (tmp2) | |
74 | : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); | |
75 | #elif defined(__x86_64__) | |
76 | __asm__ ( | |
3b217116 | 77 | "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]" |
de2d1a52 ZA |
78 | : [lo]"=a"(product), |
79 | [hi]"=d"(tmp) | |
80 | : "0"(delta), | |
81 | [mul_frac]"rm"((u64)mul_frac)); | |
347bb444 ZA |
82 | #else |
83 | #error implement me! | |
84 | #endif | |
85 | ||
86 | return product; | |
87 | } | |
88 | ||
dce2db0a | 89 | static __always_inline |
a5a1d1c2 | 90 | u64 __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc) |
dce2db0a | 91 | { |
108b249c | 92 | u64 delta = tsc - src->tsc_timestamp; |
a5a1d1c2 | 93 | u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul, |
3aed64f6 PB |
94 | src->tsc_shift); |
95 | return src->system_time + offset; | |
dce2db0a MT |
96 | } |
97 | ||
71056ae2 MT |
98 | struct pvclock_vsyscall_time_info { |
99 | struct pvclock_vcpu_time_info pvti; | |
71056ae2 MT |
100 | } __attribute__((__aligned__(SMP_CACHE_BYTES))); |
101 | ||
102 | #define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info) | |
71056ae2 | 103 | |
1965aae3 | 104 | #endif /* _ASM_X86_PVCLOCK_H */ |