clocksource/drivers/hyper-v: Suspend/resume Hyper-V clocksource for hibernation (1349401f) · Commits · 戴 / test

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 −0

Original line number	Diff line number	Diff line
		@@ -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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