From f23f37fe702fec4d6e250354432f1921ec9fe5b4 Mon Sep 17 00:00:00 2001 From: Yubo Xie Date: Thu, 26 Mar 2020 19:11:59 -0700 Subject: [PATCH] clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources [ Upstream commit 0af3e137c144377fbaf5025ba784ff5ba7ad40c9 ] hyperv_timer.c exports hyperv_cs, which is used by stimers and the timesync mechanism. However, the clocksource dependency is not needed: these mechanisms only depend on the partition reference counter (which can be read via a MSR or via the TSC Reference Page). Introduce the (function) pointer hv_read_reference_counter, as an embodiment of the partition reference counter read, and export it in place of the hyperv_cs pointer. The latter can be removed. This should clarify that there's no relationship between Hyper-V stimers & timesync and the Linux clocksource abstractions. No functional or semantic change. Suggested-by: Michael Kelley Signed-off-by: Andrea Parri Reviewed-by: Michael Kelley Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20200109160650.16150-2-parri.andrea@gmail.com Signed-off-by: Sasha Levin --- drivers/clocksource/hyperv_timer.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 2317d4e3daaf..36933e2b3b0d 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -233,7 +233,8 @@ static u64 notrace read_hv_clock_tsc(struct clocksource *arg) static u64 read_hv_sched_clock_tsc(void) { - return read_hv_clock_tsc(NULL) - hv_sched_clock_offset; + return (read_hv_clock_tsc(NULL) - hv_sched_clock_offset) * + (NSEC_PER_SEC / HV_CLOCK_HZ); } static struct clocksource hyperv_cs_tsc = { @@ -258,7 +259,8 @@ static u64 notrace read_hv_clock_msr(struct clocksource *arg) static u64 read_hv_sched_clock_msr(void) { - return read_hv_clock_msr(NULL) - hv_sched_clock_offset; + return (read_hv_clock_msr(NULL) - hv_sched_clock_offset) * + (NSEC_PER_SEC / HV_CLOCK_HZ); } static struct clocksource hyperv_cs_msr = {