s390/smp: fix smp_stop_cpu() for !CONFIG_SMP

smp_stop_cpu() should stop the current cpu even for !CONFIG_SMP.
Otherwise machine_halt() will return and and the machine generates a
panic instread of simply stopping the current cpu:

Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000

CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 3.14.0-01527-g2b6ef16a6bc5 #10
[...]
Call Trace:
([<0000000000110db0>] show_trace+0xf8/0x158)
 [<0000000000110e7a>] show_stack+0x6a/0xe8
 [<000000000074dba8>] panic+0xe4/0x268
 [<0000000000140570>] do_exit+0xa88/0xb2c
 [<000000000016e12c>] SyS_reboot+0x1f0/0x234
 [<000000000075da70>] sysc_nr_ok+0x22/0x28
 [<000000007d5a09b4>] 0x7d5a09b4

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2014-04-04 11:23:03 +02:00 committed by Martin Schwidefsky
commit e7c46c66db
3 changed files with 31 additions and 16 deletions

View file

@ -7,6 +7,8 @@
#ifndef __ASM_SMP_H
#define __ASM_SMP_H
#include <asm/sigp.h>
#ifdef CONFIG_SMP
#include <asm/lowcore.h>
@ -50,9 +52,18 @@ static inline int smp_store_status(int cpu) { return 0; }
static inline int smp_vcpu_scheduled(int cpu) { return 1; }
static inline void smp_yield_cpu(int cpu) { }
static inline void smp_yield(void) { }
static inline void smp_stop_cpu(void) { }
static inline void smp_fill_possible_mask(void) { }
static inline void smp_stop_cpu(void)
{
u16 pcpu = stap();
for (;;) {
__pcpu_sigp(pcpu, SIGP_STOP, 0, NULL);
cpu_relax();
}
}
#endif /* CONFIG_SMP */
#ifdef CONFIG_HOTPLUG_CPU