The core device API performs extra housekeeping bits that are missing
from directly calling cpu_up/down.
See commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and
serialization during LPM") for an example description of what might go
wrong.
This also prepares to make cpu_up/down a private interface for anything
but the cpu subsystem.
Acked-by: Michael Ellerman <[email protected]>
Signed-off-by: Qais Yousef <[email protected]>
CC: Benjamin Herrenschmidt <[email protected]>
CC: Paul Mackerras <[email protected]>
CC: Michael Ellerman <[email protected]>
CC: Enrico Weigelt <[email protected]>
CC: Ram Pai <[email protected]>
CC: Nicholas Piggin <[email protected]>
CC: Thiago Jung Bauermann <[email protected]>
CC: Christophe Leroy <[email protected]>
CC: Thomas Gleixner <[email protected]>
CC: [email protected]
CC: [email protected]
---
arch/powerpc/kernel/machine_kexec_64.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 04a7cba58eff..ebf8cc7acc4d 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -208,13 +208,15 @@ static void wake_offline_cpus(void)
{
int cpu = 0;
+ lock_device_hotplug();
for_each_present_cpu(cpu) {
if (!cpu_online(cpu)) {
printk(KERN_INFO "kexec: Waking offline cpu %d.\n",
cpu);
- WARN_ON(cpu_up(cpu));
+ WARN_ON(device_online(get_cpu_device(cpu)));
}
}
+ unlock_device_hotplug();
}
static void kexec_prepare_cpus(void)
--
2.17.1