From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: [patch 04/18] x86: pvclock: create helper for pvclock data retrieval Date: Wed, 24 Oct 2012 11:13:44 -0200 Message-ID: <20121024131621.475501293@redhat.com> References: <20121024131340.742340256@redhat.com> Cc: johnstul@us.ibm.com, jeremy@goop.org, glommer@parallels.com, zamsden@gmail.com, gleb@redhat.com, avi@redhat.com, pbonzini@redhat.com, Marcelo Tosatti To: kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:2573 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756422Ab2JXNQ4 (ORCPT ); Wed, 24 Oct 2012 09:16:56 -0400 Content-Disposition: inline; filename=03-move-pvread-to-pvheader Sender: kvm-owner@vger.kernel.org List-ID: Originally from Jeremy Fitzhardinge. So code can be reused. Signed-off-by: Marcelo Tosatti Index: vsyscall/arch/x86/kernel/pvclock.c =================================================================== --- vsyscall.orig/arch/x86/kernel/pvclock.c +++ vsyscall/arch/x86/kernel/pvclock.c @@ -26,13 +26,6 @@ void pvclock_set_flags(u8 flags) valid_flags = flags; } -static u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src) -{ - u64 delta = native_read_tsc() - src->tsc_timestamp; - return pvclock_scale_delta(delta, src->tsc_to_system_mul, - src->tsc_shift); -} - unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src) { u64 pv_tsc_khz = 1000000ULL << 32; @@ -55,15 +48,11 @@ void pvclock_resume(void) cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) { unsigned version; - cycle_t ret, offset; + cycle_t ret; u64 last; do { - version = src->version; - rdtsc_barrier(); - offset = pvclock_get_nsec_offset(src); - ret = src->system_time + offset; - rdtsc_barrier(); + version = __pvclock_read_cycles(src, &ret); } while ((src->version & 1) || version != src->version); if ((valid_flags & PVCLOCK_TSC_STABLE_BIT) && Index: vsyscall/arch/x86/include/asm/pvclock.h =================================================================== --- vsyscall.orig/arch/x86/include/asm/pvclock.h +++ vsyscall/arch/x86/include/asm/pvclock.h @@ -56,4 +56,29 @@ static inline u64 pvclock_scale_delta(u6 return product; } +static __always_inline +u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src) +{ + u64 delta = __native_read_tsc() - src->tsc_timestamp; + return pvclock_scale_delta(delta, src->tsc_to_system_mul, + src->tsc_shift); +} + +static __always_inline +unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, + cycle_t *cycles) +{ + unsigned version; + cycle_t ret, offset; + + version = src->version; + rdtsc_barrier(); + offset = pvclock_get_nsec_offset(src); + ret = src->system_time + offset; + rdtsc_barrier(); + + *cycles = ret; + return version; +} + #endif /* _ASM_X86_PVCLOCK_H */