linux-kernel - [PATCH v5 3/4] intel_idle: Use __update_spec_ctrl() in intel_idle

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Message-Id: <20230710194857.2898284-4-longman@redhat.com>
Date:   Mon, 10 Jul 2023 15:48:56 -0400
From:   Waiman Long <longman@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Josh Poimboeuf <jpoimboe@...nel.org>,
        Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
        Jacob Pan <jacob.jun.pan@...ux.intel.com>,
        Len Brown <lenb@...nel.org>, Jonathan Corbet <corbet@....net>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>
Cc:     linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org,
        x86@...nel.org, linux-pm@...r.kernel.org,
        Robin Jarry <rjarry@...hat.com>, Joe Mario <jmario@...hat.com>,
        Randy Dunlap <rdunlap@...radead.org>,
        Waiman Long <longman@...hat.com>
Subject: [PATCH v5 3/4] intel_idle: Use __update_spec_ctrl() in intel_idle_ibrs()

When intel_idle_ibrs() is called, it modifies the SPEC_CTRL MSR to 0
in order disable IBRS. However, the new MSR value isn't reflected in
x86_spec_ctrl_current which is at odd with the other code that keep track
of its state in that percpu variable.  Use the new __update_spec_ctrl()
to have the x86_spec_ctrl_current percpu value properly updated.

Signed-off-by: Waiman Long <longman@...hat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/idle/intel_idle.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index b930036edbbe..c9479f089037 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -182,12 +182,12 @@ static __cpuidle int intel_idle_ibrs(struct cpuidle_device *dev,
 	int ret;
 
 	if (smt_active)
-		native_wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+		__update_spec_ctrl(0);
 
 	ret = __intel_idle(dev, drv, index);
 
 	if (smt_active)
-		native_wrmsrl(MSR_IA32_SPEC_CTRL, spec_ctrl);
+		__update_spec_ctrl(spec_ctrl);
 
 	return ret;
 }
-- 
2.31.1