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
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

View File

@ -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)