linux-kernel - [tip: smp/core] ARM: Don't use disable_nonboot

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Date:   Wed, 25 Mar 2020 12:06:05 -0000
From:   "tip-bot2 for Qais Yousef" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Qais Yousef <qais.yousef@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Russell King <linux@...linux.org.uk>, x86 <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: [tip: smp/core] ARM: Don't use disable_nonboot_cpus()

The following commit has been merged into the smp/core branch of tip:

Commit-ID:     dddf3578e0d497e66ebe654d0f3258ac20a07e27
Gitweb:        https://git.kernel.org/tip/dddf3578e0d497e66ebe654d0f3258ac20a07e27
Author:        Qais Yousef <qais.yousef@....com>
AuthorDate:    Mon, 23 Mar 2020 13:50:57 
Committer:     Thomas Gleixner <tglx@...utronix.de>
CommitterDate: Wed, 25 Mar 2020 12:59:32 +01:00

ARM: 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 turn 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>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Russell King <linux@...linux.org.uk>
Link: https://lkml.kernel.org/r/20200323135110.30522-5-qais.yousef@arm.com

---
 arch/arm/kernel/reboot.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/reboot.c b/arch/arm/kernel/reboot.c
index bb18ed0..58ad1a7 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);
 }
 
 /*