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

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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
This commit is contained in:
Dexuan Cui 2019-11-19 23:12:26 -08:00 committed by Daniel Lezcano
parent 5167c506d6
commit 1349401ff1
1 changed files with 25 additions and 0 deletions
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25
drivers/clocksource/hyperv_timer.c
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@ -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)