linux-kernel - [PATCH v2 03/14] arm: arm64: Don't use disable_nonboot

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Message-Id: <20191125112754.25223-4-qais.yousef@arm.com>
Date:   Mon, 25 Nov 2019 11:27:43 +0000
From:   Qais Yousef <qais.yousef@....com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Qais Yousef <qais.yousef@....com>,
        Russell King <linux@...linux.org.uk>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 03/14] arm: arm64: Don't use disable_nonboot_cpus()

disable_nonboot_cpus() is not safe to use when doing machine_down(),
because it relies on freeze_secondary_cpus() which in return is
a suspend/resume related freeze and could abort if the logic detects any
pending activities that can prevent finishing the offlining process.

Beside disable_nonboot_cpus() is dependent on CONFIG_PM_SLEEP_SMP which
is an othogonal config to rely on to ensure this function works
correctly.

Signed-off-by: Qais Yousef <qais.yousef@....com>
CC: Russell King <linux@...linux.org.uk>
CC: Catalin Marinas <catalin.marinas@....com>
CC: Will Deacon <will@...nel.org>
CC: linux-arm-kernel@...ts.infradead.org
CC: linux-kernel@...r.kernel.org
---
 arch/arm/kernel/reboot.c    | 4 ++--
 arch/arm64/kernel/process.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kernel/reboot.c b/arch/arm/kernel/reboot.c
index bb18ed0539f4..58ad1a70f770 100644
--- a/arch/arm/kernel/reboot.c
+++ b/arch/arm/kernel/reboot.c
@@ -88,11 +88,11 @@ void soft_restart(unsigned long addr)
  * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
  * kexec'd kernel to use any and all RAM as it sees fit, without having to
  * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
- * functionality embodied in disable_nonboot_cpus() to achieve this.
+ * functionality embodied in smp_shutdown_nonboot_cpus() to achieve this.
  */
 void machine_shutdown(void)
 {
-	disable_nonboot_cpus();
+	smp_shutdown_nonboot_cpus(0);
 }
 
 /*
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 71f788cd2b18..3bcc9bfc581e 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -141,11 +141,11 @@ void arch_cpu_idle_dead(void)
  * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
  * kexec'd kernel to use any and all RAM as it sees fit, without having to
  * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
- * functionality embodied in disable_nonboot_cpus() to achieve this.
+ * functionality embodied in smpt_shutdown_nonboot_cpus() to achieve this.
  */
 void machine_shutdown(void)
 {
-	disable_nonboot_cpus();
+	smp_shutdown_nonboot_cpus(0);
 }
 
 /*
-- 
2.17.1