[S390] Force PSW restart on online CPU

PSW restart can be triggered on offline CPUs. If this happens, currently
the PSW restart code fails, because functions like smp_processor_id()
do not work on offline CPUs. This patch fixes this as follows:

If PSW restart is triggered on an offline CPU, the PSW restart (sigp restart)
is done a second time on another CPU that is online and the old CPU is
stopped afterwards.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index 045e009fc164..ab47a69fdf07 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -33,6 +33,7 @@ extern struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
 extern void smp_switch_to_ipl_cpu(void (*func)(void *), void *);
 extern void smp_switch_to_cpu(void (*)(void *), void *, unsigned long sp,
                               int from, int to);
+extern void smp_restart_with_online_cpu(void);
 extern void smp_restart_cpu(void);
 
 /*
@@ -64,6 +65,10 @@ static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
         func(data);
 }
 
+static inline void smp_restart_with_online_cpu(void)
+{
+}
+
 #define smp_vcpu_scheduled      (1)
 
 #endif /* CONFIG_SMP */