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106 lines
2.6 KiB
106 lines
2.6 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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#ifndef _ASM_X86_PVCLOCK_H |
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#define _ASM_X86_PVCLOCK_H |
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#include <asm/clocksource.h> |
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#include <asm/pvclock-abi.h> |
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/* some helper functions for xen and kvm pv clock sources */ |
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u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); |
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u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src); |
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void pvclock_set_flags(u8 flags); |
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unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); |
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void pvclock_read_wallclock(struct pvclock_wall_clock *wall, |
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struct pvclock_vcpu_time_info *vcpu, |
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struct timespec64 *ts); |
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void pvclock_resume(void); |
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void pvclock_touch_watchdogs(void); |
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static __always_inline |
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unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src) |
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{ |
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unsigned version = src->version & ~1; |
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/* Make sure that the version is read before the data. */ |
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virt_rmb(); |
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return version; |
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} |
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static __always_inline |
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bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src, |
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unsigned version) |
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{ |
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/* Make sure that the version is re-read after the data. */ |
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virt_rmb(); |
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return unlikely(version != src->version); |
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} |
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/* |
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* Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, |
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* yielding a 64-bit result. |
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*/ |
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static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) |
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{ |
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u64 product; |
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#ifdef __i386__ |
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u32 tmp1, tmp2; |
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#else |
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ulong tmp; |
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#endif |
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if (shift < 0) |
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delta >>= -shift; |
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else |
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delta <<= shift; |
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#ifdef __i386__ |
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__asm__ ( |
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"mul %5 ; " |
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"mov %4,%%eax ; " |
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"mov %%edx,%4 ; " |
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"mul %5 ; " |
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"xor %5,%5 ; " |
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"add %4,%%eax ; " |
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"adc %5,%%edx ; " |
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: "=A" (product), "=r" (tmp1), "=r" (tmp2) |
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: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); |
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#elif defined(__x86_64__) |
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__asm__ ( |
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"mulq %[mul_frac] ; shrd $32, %[hi], %[lo]" |
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: [lo]"=a"(product), |
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[hi]"=d"(tmp) |
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: "0"(delta), |
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[mul_frac]"rm"((u64)mul_frac)); |
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#else |
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#error implement me! |
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#endif |
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return product; |
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} |
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static __always_inline |
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u64 __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc) |
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{ |
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u64 delta = tsc - src->tsc_timestamp; |
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u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul, |
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src->tsc_shift); |
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return src->system_time + offset; |
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} |
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struct pvclock_vsyscall_time_info { |
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struct pvclock_vcpu_time_info pvti; |
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} __attribute__((__aligned__(SMP_CACHE_BYTES))); |
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#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info) |
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#ifdef CONFIG_PARAVIRT_CLOCK |
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void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti); |
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struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void); |
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#else |
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static inline struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void) |
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{ |
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return NULL; |
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} |
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#endif |
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#endif /* _ASM_X86_PVCLOCK_H */
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