From eb3e1d370b4c57be1acbb9de51a7deaa036eff4b Mon Sep 17 00:00:00 2001 From: Michael Kelley Date: Tue, 2 Mar 2021 13:38:20 -0800 Subject: clocksource/drivers/hyper-v: Handle sched_clock differences inline While the Hyper-V Reference TSC code is architecture neutral, the pv_ops.time.sched_clock() function is implemented for x86/x64, but not for ARM64. Current code calls a utility function under arch/x86 (and coming, under arch/arm64) to handle the difference. Change this approach to handle the difference inline based on whether GENERIC_SCHED_CLOCK is present. The new approach removes code under arch/* since the difference is tied more to the specifics of the Linux implementation than to the architecture. No functional change. Signed-off-by: Michael Kelley Reviewed-by: Boqun Feng Acked-by: Daniel Lezcano Link: https://lore.kernel.org/r/1614721102-2241-9-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu --- drivers/clocksource/hyperv_timer.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'drivers') diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 06984fa11936..10eb5c645141 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -423,6 +423,30 @@ static struct clocksource hyperv_cs_msr = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +/* + * Reference to pv_ops must be inline so objtool + * detection of noinstr violations can work correctly. + */ +#ifdef CONFIG_GENERIC_SCHED_CLOCK +static __always_inline void hv_setup_sched_clock(void *sched_clock) +{ + /* + * We're on an architecture with generic sched clock (not x86/x64). + * The Hyper-V sched clock read function returns nanoseconds, not + * the normal 100ns units of the Hyper-V synthetic clock. + */ + sched_clock_register(sched_clock, 64, NSEC_PER_SEC); +} +#elif defined CONFIG_PARAVIRT +static __always_inline void hv_setup_sched_clock(void *sched_clock) +{ + /* We're on x86/x64 *and* using PV ops */ + pv_ops.time.sched_clock = sched_clock; +} +#else /* !CONFIG_GENERIC_SCHED_CLOCK && !CONFIG_PARAVIRT */ +static __always_inline void hv_setup_sched_clock(void *sched_clock) {} +#endif /* CONFIG_GENERIC_SCHED_CLOCK */ + static bool __init hv_init_tsc_clocksource(void) { u64 tsc_msr; -- cgit v1.2.3