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>
raspberrypi · Apr 9, 2014 · e7c46c6 · e7c46c6
1 parent a8a934e
commit e7c46c6
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Showing 3 changed files with 31 additions and 16 deletions.
diff --git a/arch/s390/include/asm/sigp.h b/arch/s390/include/asm/sigp.h
@@ -31,4 +31,23 @@
 #define SIGP_STATUS_INCORRECT_STATE 0x00000200UL
 #define SIGP_STATUS_NOT_RUNNING 0x00000400UL
 
+#ifndef __ASSEMBLY__
+
+static inline int __pcpu_sigp(u16 addr, u8 order, u32 parm, u32 *status)
+{
+ register unsigned int reg1 asm ("1") = parm;
+ int cc;
+
+ asm volatile(
+ " sigp %1,%2,0(%3)\n"
+ " ipm %0\n"
+ " srl %0,28\n"
+ : "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
+ if (status && cc == 1)
+ *status = reg1;
+ return cc;
+}
+
+#endif /* __ASSEMBLY__ */
+
 #endif /* __S390_ASM_SIGP_H */
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
@@ -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

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
@@ -82,21 +82,6 @@ DEFINE_MUTEX(smp_cpu_state_mutex);
 /*
  * Signal processor helper functions.
  */
-static inline int __pcpu_sigp(u16 addr, u8 order, u32 parm, u32 *status)
-{
- register unsigned int reg1 asm ("1") = parm;
- int cc;
-
- asm volatile(
- " sigp %1,%2,0(%3)\n"
- " ipm %0\n"
- " srl %0,28\n"
- : "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
- if (status && cc == 1)
- *status = reg1;
- return cc;
-}
-
 static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status)
 {
  int cc;