[v8,10/19] arm: tegra20: cpuidle: Make abort_flag atomic

Message ID	20191203004116.11771-11-digetx@gmail.com
State	Superseded
Headers	show Return-Path: <linux-tegra-owner@vger.kernel.org> From: Dmitry Osipenko <digetx@gmail.com> To: Thierry Reding <thierry.reding@gmail.com>, Jonathan Hunter <jonathanh@nvidia.com>, Peter De Schrijver <pdeschrijver@nvidia.com>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v8 10/19] arm: tegra20: cpuidle: Make abort_flag atomic Date: Tue, 3 Dec 2019 03:41:07 +0300 Message-Id: <20191203004116.11771-11-digetx@gmail.com> In-Reply-To: <20191203004116.11771-1-digetx@gmail.com> References: <20191203004116.11771-1-digetx@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk
Series	Consolidate and improve NVIDIA Tegra CPUIDLE driver(s) \| expand [v8,00/19] Consolidate and improve NVIDIA Tegra CPUIDLE driver(s) [v8,01/19] ARM: tegra: Compile sleep-tegra20/30.S unconditionally [v8,02/19] ARM: tegra: Add tegra_pm_park_secondary_cpu() [v8,03/19] ARM: tegra: Remove pen-locking from cpuidle-tegra20 [v8,04/19] ARM: tegra: Change tegra_set_cpu_in_lp2() type to void [v8,05/19] ARM: tegra: Propagate error from tegra_idle_lp2_last() [v8,06/19] ARM: tegra: Expose PM functions required for new cpuidle driver [v8,07/19] ARM: tegra: Rename some of the newly exposed PM functions [v8,08/19] ARM: tegra: Make outer_disable() open-coded [v8,09/19] arm: tegra20: cpuidle: Handle case where secondary CPU hangs on entering LP2 [v8,10/19] arm: tegra20: cpuidle: Make abort_flag atomic [v8,11/19] arm: tegra20/30: cpuidle: Remove unnecessary memory barrier [v8,12/19] cpuidle: Avoid NULL dereference in cpuidle_driver_state_disabled() [v8,13/19] cpuidle: Refactor and move out NVIDIA Tegra20 driver into drivers/cpuidle [v8,14/19] cpuidle: tegra: Squash Tegra30 driver into the common driver [v8,15/19] cpuidle: tegra: Support CPU cluster power-down state on Tegra30 [v8,16/19] cpuidle: tegra: Squash Tegra114 driver into the common driver [v8,17/19] cpuidle: tegra: Disable CC6 state if LP2 unavailable [v8,18/19] ARM: multi_v7_defconfig: Enable Tegra cpuidle driver [v8,19/19] ARM: tegra: Enable Tegra cpuidle driver in tegra_defconfig

Message ID

20191203004116.11771-11-digetx@gmail.com

State

Superseded

Headers

From: Dmitry Osipenko <digetx@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Peter De Schrijver <pdeschrijver@nvidia.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v8 10/19] arm: tegra20: cpuidle: Make abort_flag atomic
Date: Tue,  3 Dec 2019 03:41:07 +0300
Message-Id: <20191203004116.11771-11-digetx@gmail.com>
In-Reply-To: <20191203004116.11771-1-digetx@gmail.com>
References: <20191203004116.11771-1-digetx@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-tegra-owner@vger.kernel.org
Precedence: bulk

Series

Consolidate and improve NVIDIA Tegra CPUIDLE driver(s) | expand

Commit Message

Dmitry Osipenko Dec. 3, 2019, 12:41 a.m. UTC

Replace memory accessors with atomic API just to make code consistent
with the abort_barrier. The new variant may be even more correct now since
atomic_read() will prevent compiler from generating wrong things like
carrying abort_flag value in a register instead of re-fetching it from
memory.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/mach-tegra/cpuidle-tegra20.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-tegra/cpuidle-tegra20.c b/arch/arm/mach-tegra/cpuidle-tegra20.c
index f3a898f69a1d..3f4c75dbb4aa 100644
--- a/arch/arm/mach-tegra/cpuidle-tegra20.c
+++ b/arch/arm/mach-tegra/cpuidle-tegra20.c
@@ -32,7 +32,7 @@ 
 #include "sleep.h"
 
 #ifdef CONFIG_PM_SLEEP
-static bool abort_flag;
+static atomic_t abort_flag;
 static atomic_t abort_barrier;
 static int tegra20_idle_lp2_coupled(struct cpuidle_device *dev,
 				    struct cpuidle_driver *drv,
@@ -167,13 +167,14 @@  static int tegra20_idle_lp2_coupled(struct cpuidle_device *dev,
 	bool entered_lp2 = false;
 
 	if (tegra_pending_sgi())
-		WRITE_ONCE(abort_flag, true);
+		atomic_set(&abort_flag, 1);
 
 	cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
 
-	if (abort_flag) {
+	if (atomic_read(&abort_flag)) {
 		cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
-		abort_flag = false;	/* clean flag for next coming */
+		/* clean flag for next coming */
+		atomic_set(&abort_flag, 0);
 		return -EINTR;
 	}

[v8,10/19] arm: tegra20: cpuidle: Make abort_flag atomic

Commit Message

Patch