[PATCH v2 03/14] arm: arm64: Don't use disable_nonboot_cpus()

Qais Yousef
2019-11-25T11:28:12Z

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@arm.com>
CC: Russell King <linux@armlinux.org.uk>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will@kernel.org>
CC: linux-arm-kernel@lists.infradead.org
CC: linux-kernel@vger.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