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* [PATCH v6] clocksource/drivers: Suspend/resume Hyper-V clocksource for hibernation
@ 2019-11-20  7:12 Dexuan Cui
  2019-12-04 16:05 ` Daniel Lezcano
  2020-01-16 21:31 ` [tip: timers/core] clocksource/drivers/hyper-v: " tip-bot2 for Dexuan Cui
  0 siblings, 2 replies; 3+ messages in thread
From: Dexuan Cui @ 2019-11-20  7:12 UTC (permalink / raw)
  To: arnd, bp, daniel.lezcano, haiyangz, hpa, kys, linux-hyperv,
	linux-kernel, mingo, sashal, sthemmin, tglx, x86, mikelley,
	Alexander.Levin, vkuznets
  Cc: linux-arch, Dexuan Cui

This is needed for hibernation, e.g. when we resume the old kernel, we need
to disable the "current" kernel's TSC page and then resume the old kernel's.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
---

This patch is part of the v5 patchset:
  https://lkml.org/lkml/2019/9/5/1158
  https://lkml.org/lkml/2019/9/5/1161

  Actually v6 is the same as v1 (v2~v5 were posted with the other patches).

  Please pick up this patch into the tip.git tree, probably onto the branch
timers/core.

 drivers/clocksource/hyperv_timer.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index 287d8d58c21a..1aec08e82b7a 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -330,12 +330,37 @@ static u64 read_hv_sched_clock_tsc(void)
 	return read_hv_clock_tsc(NULL) - hv_sched_clock_offset;
 }
 
+static void suspend_hv_clock_tsc(struct clocksource *arg)
+{
+	u64 tsc_msr;
+
+	/* Disable the TSC page */
+	hv_get_reference_tsc(tsc_msr);
+	tsc_msr &= ~BIT_ULL(0);
+	hv_set_reference_tsc(tsc_msr);
+}
+
+
+static void resume_hv_clock_tsc(struct clocksource *arg)
+{
+	phys_addr_t phys_addr = virt_to_phys(&tsc_pg);
+	u64 tsc_msr;
+
+	/* Re-enable the TSC page */
+	hv_get_reference_tsc(tsc_msr);
+	tsc_msr &= GENMASK_ULL(11, 0);
+	tsc_msr |= BIT_ULL(0) | (u64)phys_addr;
+	hv_set_reference_tsc(tsc_msr);
+}
+
 static struct clocksource hyperv_cs_tsc = {
 	.name	= "hyperv_clocksource_tsc_page",
 	.rating	= 400,
 	.read	= read_hv_clock_tsc,
 	.mask	= CLOCKSOURCE_MASK(64),
 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
+	.suspend= suspend_hv_clock_tsc,
+	.resume	= resume_hv_clock_tsc,
 };
 
 static u64 notrace read_hv_clock_msr(struct clocksource *arg)
-- 
2.19.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH v6] clocksource/drivers: Suspend/resume Hyper-V clocksource for hibernation
  2019-11-20  7:12 [PATCH v6] clocksource/drivers: Suspend/resume Hyper-V clocksource for hibernation Dexuan Cui
@ 2019-12-04 16:05 ` Daniel Lezcano
  2020-01-16 21:31 ` [tip: timers/core] clocksource/drivers/hyper-v: " tip-bot2 for Dexuan Cui
  1 sibling, 0 replies; 3+ messages in thread
From: Daniel Lezcano @ 2019-12-04 16:05 UTC (permalink / raw)
  To: decui, arnd, bp, haiyangz, hpa, kys, linux-hyperv, linux-kernel,
	mingo, sashal, sthemmin, tglx, x86, mikelley, Alexander.Levin,
	vkuznets
  Cc: linux-arch

On 20/11/2019 08:12, Dexuan Cui wrote:
> This is needed for hibernation, e.g. when we resume the old kernel, we need
> to disable the "current" kernel's TSC page and then resume the old kernel's.
> 
> Signed-off-by: Dexuan Cui <decui@microsoft.com>
> Reviewed-by: Michael Kelley <mikelley@microsoft.com>
> ---
> 
> This patch is part of the v5 patchset:
>   https://lkml.org/lkml/2019/9/5/1158
>   https://lkml.org/lkml/2019/9/5/1161
> 
>   Actually v6 is the same as v1 (v2~v5 were posted with the other patches).
> 
>   Please pick up this patch into the tip.git tree, probably onto the branch
> timers/core.

Applied, thanks!


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^ permalink raw reply	[flat|nested] 3+ messages in thread
* [tip: timers/core] clocksource/drivers/hyper-v: Suspend/resume Hyper-V clocksource for hibernation
  2019-11-20  7:12 [PATCH v6] clocksource/drivers: Suspend/resume Hyper-V clocksource for hibernation Dexuan Cui
  2019-12-04 16:05 ` Daniel Lezcano
@ 2020-01-16 21:31 ` tip-bot2 for Dexuan Cui
  1 sibling, 0 replies; 3+ messages in thread
From: tip-bot2 for Dexuan Cui @ 2020-01-16 21:31 UTC (permalink / raw)
  To: linux-tip-commits; +Cc: Dexuan Cui, Michael Kelley, Daniel Lezcano, x86, LKML

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     1349401ff1aa425e7381ed26feb63e0d6b557fc6
Gitweb:        https://git.kernel.org/tip/1349401ff1aa425e7381ed26feb63e0d6b557fc6
Author:        Dexuan Cui <decui@microsoft.com>
AuthorDate:    Tue, 19 Nov 2019 23:12:26 -08:00
Committer:     Daniel Lezcano <daniel.lezcano@linaro.org>
CommitterDate: Thu, 16 Jan 2020 19:06:57 +01:00

clocksource/drivers/hyper-v: Suspend/resume Hyper-V clocksource for hibernation

This is needed for hibernation, e.g. when we resume the old kernel, we need
to disable the "current" kernel's TSC page and then resume the old kernel's.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1574233946-48377-1-git-send-email-decui@microsoft.com
---
 drivers/clocksource/hyperv_timer.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index 287d8d5..1aec08e 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -330,12 +330,37 @@ static u64 read_hv_sched_clock_tsc(void)
 	return read_hv_clock_tsc(NULL) - hv_sched_clock_offset;
 }
 
+static void suspend_hv_clock_tsc(struct clocksource *arg)
+{
+	u64 tsc_msr;
+
+	/* Disable the TSC page */
+	hv_get_reference_tsc(tsc_msr);
+	tsc_msr &= ~BIT_ULL(0);
+	hv_set_reference_tsc(tsc_msr);
+}
+
+
+static void resume_hv_clock_tsc(struct clocksource *arg)
+{
+	phys_addr_t phys_addr = virt_to_phys(&tsc_pg);
+	u64 tsc_msr;
+
+	/* Re-enable the TSC page */
+	hv_get_reference_tsc(tsc_msr);
+	tsc_msr &= GENMASK_ULL(11, 0);
+	tsc_msr |= BIT_ULL(0) | (u64)phys_addr;
+	hv_set_reference_tsc(tsc_msr);
+}
+
 static struct clocksource hyperv_cs_tsc = {
 	.name	= "hyperv_clocksource_tsc_page",
 	.rating	= 400,
 	.read	= read_hv_clock_tsc,
 	.mask	= CLOCKSOURCE_MASK(64),
 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
+	.suspend= suspend_hv_clock_tsc,
+	.resume	= resume_hv_clock_tsc,
 };
 
 static u64 notrace read_hv_clock_msr(struct clocksource *arg)

^ permalink raw reply related	[flat|nested] 3+ messages in thread
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2019-11-20  7:12 [PATCH v6] clocksource/drivers: Suspend/resume Hyper-V clocksource for hibernation Dexuan Cui
2019-12-04 16:05 ` Daniel Lezcano
2020-01-16 21:31 ` [tip: timers/core] clocksource/drivers/hyper-v: " tip-bot2 for Dexuan Cui

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