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 <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
---
This is a RESEND of https://lore.kernel.org/patchwork/patch/1156212/ .
Daniel Lezcano said "Applied, thanks!" on 12/4/2019 (see the above link),
but I still can not find it in the mainline tree, or the tip tree.
So, let me resend it just in case.
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
On 06/01/2020 23:43, 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 <[email protected]>
> Reviewed-by: Michael Kelley <[email protected]>
> ---
>
> This is a RESEND of https://lore.kernel.org/patchwork/patch/1156212/ .
>
> Daniel Lezcano said "Applied, thanks!" on 12/4/2019 (see the above link),
> but I still can not find it in the mainline tree, or the tip tree.
Yes, it is applied but it did not reached the tip tree yet.
> So, let me resend it just in case.
>
> 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)
>
--
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