linux-kernel - [PATCH V2] x86/Hyper-V: Fix hv sched clock function return wrong time unit

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Date:   Thu, 26 Mar 2020 19:11:59 -0700
From:   Tianyu Lan <ltykernel@...il.com>
To:     kys@...rosoft.com, haiyangz@...rosoft.com, sthemmin@...rosoft.com,
        liuwe@...rosoft.com, daniel.lezcano@...aro.org, tglx@...utronix.de,
        michael.h.kelley@...rosoft.com
Cc:     Tianyu Lan <Tianyu.Lan@...rosoft.com>,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org,
        vkuznets@...hat.com, stable@...r.kernel.org,
        Yubo Xie <yuboxie@...rosoft.com>
Subject: [PATCH V2] x86/Hyper-V: Fix hv sched clock function return wrong time unit

From: Yubo Xie <yuboxie@...rosoft.com>

sched clock callback should return time with nano second as unit
but current hv callback returns time with 100ns. Fix it.

Cc: stable@...r.kernel.org
Signed-off-by: Yubo Xie <yuboxie@...rosoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@...rosoft.com>
Fixes: bd00cd52d5be ("clocksource/drivers/hyperv: Add Hyper-V specific sched clock function")
---
Change since v1:
	Update fix commit number in change log. 
---
 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 9d808d595ca8..662ed978fa24 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 = {
-- 
2.14.5