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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 | /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_PVCLOCK_H #define _ASM_X86_PVCLOCK_H #include <asm/barrier.h> #include <asm/pvclock-abi.h> /* some helper functions for xen and kvm pv clock sources */ u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src); void pvclock_set_flags(u8 flags); unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); void pvclock_resume(void); void pvclock_touch_watchdogs(void); static __always_inline unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src) { unsigned version = src->version & ~1; /* Make sure that the version is read before the data. */ rmb(); return version; } static __always_inline bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src, unsigned version) { /* Make sure that the version is re-read after the data. */ rmb(); return version != src->version; } /* * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, * yielding a 64-bit result. */ static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) { u64 product; #ifdef __i386__ u32 tmp1, tmp2; #else unsigned long tmp; #endif if (shift < 0) delta >>= -shift; else delta <<= shift; #ifdef __i386__ __asm__ ( "mul %5 ; " "mov %4,%%eax ; " "mov %%edx,%4 ; " "mul %5 ; " "xor %5,%5 ; " "add %4,%%eax ; " "adc %5,%%edx ; " : "=A" (product), "=r" (tmp1), "=r" (tmp2) : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); #elif defined(__x86_64__) __asm__ ( "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]" : [lo]"=a"(product), [hi]"=d"(tmp) : "0"(delta), [mul_frac]"rm"((u64)mul_frac)); #else #error implement me! #endif return product; } static __always_inline u64 __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc) { u64 delta = tsc - src->tsc_timestamp; u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul, src->tsc_shift); return src->system_time + offset; } struct pvclock_vsyscall_time_info { struct pvclock_vcpu_time_info pvti; } __attribute__((__aligned__(64))); #define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info) #ifdef CONFIG_PARAVIRT_CLOCK void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti); struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void); #else static inline struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void) { return NULL; } #endif #endif /* _ASM_X86_PVCLOCK_H */ |