[PATCH v3 05/15] arm64: Don't use disable_nonboot_cpus()

From: Qais Yousef
Date: Sun Feb 23 2020 - 14:30:05 EST


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.

Use `reboot_cpu` variable instead of hardcoding 0 as the reboot cpu.

Signed-off-by: Qais Yousef <qais.yousef@xxxxxxx>
CC: Catalin Marinas <catalin.marinas@xxxxxxx>
CC: Will Deacon <will@xxxxxxxxxx>
CC: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx
---
arch/arm64/kernel/process.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index bbb0f0c145f6..b33b415fb32e 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(reboot_cpu);
}

/*
--
2.17.1