The patch below does not apply to the 5.5-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 749da8ca978f19710aba496208c480ad42d37f79 Mon Sep 17 00:00:00 2001

From: Yubo Xie yuboxie@microsoft.com Date: Thu, 26 Mar 2020 19:11:59 -0700 Subject: [PATCH] clocksource/drivers/hyper-v: Make sched clock return nanoseconds correctly

The sched clock read functions return the HV clock (100ns granularity) without converting it to nanoseconds.

Add the missing conversion.

Fixes: bd00cd52d5be ("clocksource/drivers/hyperv: Add Hyper-V specific sched clock function") Signed-off-by: Yubo Xie yuboxie@microsoft.com Signed-off-by: Tianyu Lan Tianyu.Lan@microsoft.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Vitaly Kuznetsov vkuznets@redhat.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200327021159.31429-1-Tianyu.Lan@microsoft.com

diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 9d808d595ca8..eb0ba7818eb0 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -343,7 +343,8 @@ static u64 notrace read_hv_clock_tsc_cs(struct clocksource *arg)

static u64 read_hv_sched_clock_tsc(void) { - return read_hv_clock_tsc() - hv_sched_clock_offset; + return (read_hv_clock_tsc() - hv_sched_clock_offset) * + (NSEC_PER_SEC / HV_CLOCK_HZ); }

static void suspend_hv_clock_tsc(struct clocksource *arg) @@ -398,7 +399,8 @@ static u64 notrace read_hv_clock_msr_cs(struct clocksource *arg)

static u64 read_hv_sched_clock_msr(void) { - return read_hv_clock_msr() - hv_sched_clock_offset; + return (read_hv_clock_msr() - hv_sched_clock_offset) * + (NSEC_PER_SEC / HV_CLOCK_HZ); }

static struct clocksource hyperv_cs_msr = {