* [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
0 siblings, 1 reply; 2+ 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] 2+ 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
0 siblings, 0 replies; 2+ 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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