linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dexuan Cui <decui@microsoft.com>
To: "arnd@arndb.de" <arnd@arndb.de>, "bp@alien8.de" <bp@alien8.de>,
	"daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	"hpa@zytor.com" <hpa@zytor.com>,
	KY Srinivasan <kys@microsoft.com>,
	"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"sashal@kernel.org" <sashal@kernel.org>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"x86@kernel.org" <x86@kernel.org>,
	Michael Kelley <mikelley@microsoft.com>,
	Sasha Levin <Alexander.Levin@microsoft.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
	Dexuan Cui <decui@microsoft.com>
Subject: [PATCH v5 3/3] clocksource/drivers: Suspend/resume Hyper-V clocksource for hibernation
Date: Thu, 5 Sep 2019 22:47:15 +0000	[thread overview]
Message-ID: <1567723581-29088-4-git-send-email-decui@microsoft.com> (raw)
In-Reply-To: <1567723581-29088-1-git-send-email-decui@microsoft.com>

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>
---
 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 726a65e..07f4747 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -237,12 +237,37 @@ 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)
-- 
1.8.3.1


  parent reply	other threads:[~2019-09-05 22:47 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-05 22:47 [PATCH v5 0/3] Enhance Hyper-V for hibernation Dexuan Cui
2019-09-05 22:47 ` [PATCH v5 1/3] x86/hyper-v: Suspend/resume the hypercall page " Dexuan Cui
2019-09-26 10:44   ` Vitaly Kuznetsov
2019-09-27  6:48     ` Dexuan Cui
2019-09-27  9:05       ` Vitaly Kuznetsov
2019-09-30 18:49         ` Dexuan Cui
2019-09-05 22:47 ` [PATCH v5 2/3] x86/hyper-v: Implement hv_is_hibernation_supported() Dexuan Cui
2019-09-05 22:47 ` Dexuan Cui [this message]
2019-09-25 23:21   ` [PATCH v5 3/3] clocksource/drivers: Suspend/resume Hyper-V clocksource for hibernation Daniel Lezcano
2019-09-25 23:35     ` Dexuan Cui
2019-09-26 13:16       ` Daniel Lezcano
2019-09-27  5:57         ` Dexuan Cui
2019-09-25 22:49 ` [PATCH v5 0/3] Enhance Hyper-V " Dexuan Cui

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1567723581-29088-4-git-send-email-decui@microsoft.com \
    --to=decui@microsoft.com \
    --cc=Alexander.Levin@microsoft.com \
    --cc=arnd@arndb.de \
    --cc=bp@alien8.de \
    --cc=daniel.lezcano@linaro.org \
    --cc=haiyangz@microsoft.com \
    --cc=hpa@zytor.com \
    --cc=kys@microsoft.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mikelley@microsoft.com \
    --cc=mingo@redhat.com \
    --cc=sashal@kernel.org \
    --cc=sthemmin@microsoft.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).