[S390] smp: fix sigp stop handling

According to the architecture a cpu must not necessarily enter stopped
state after completion of a sigp instruction with "stop" order code.
So remove the BUG() statement after self sending sigp stop to avoid
that it ever gets reached.
Also add a sigp busy check to make sure that the order gets delivered.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index ee57a42..4890ac6 100644 (file)
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -1595,10 +1595,9 @@ static void stop_run(struct shutdown_trigger *trigger)
 {
        if (strcmp(trigger->name, ON_PANIC_STR) == 0)
                disabled_wait((unsigned long) __builtin_return_address(0));
-       else {
-               signal_processor(smp_processor_id(), sigp_stop);
-               for (;;);
-       }
+       while (signal_processor(smp_processor_id(), sigp_stop) == sigp_busy)
+               cpu_relax();
+       for (;;);
 }
 
 static struct shutdown_action stop_action = {SHUTDOWN_ACTION_STOP_STR,

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index c699ac5..c99c45b 100644 (file)
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -647,8 +647,8 @@ void __cpu_die(unsigned int cpu)
 void cpu_die(void)
 {
        idle_task_exit();
-       signal_processor(smp_processor_id(), sigp_stop);
-       BUG();
+       while (signal_processor(smp_processor_id(), sigp_stop) == sigp_busy)
+               cpu_relax();
        for (;;);
 }
 

diff --git a/arch/s390/kernel/swsusp_asm64.S b/arch/s390/kernel/swsusp_asm64.S
index 7c8653e..0f4ef3b 100644 (file)
--- a/arch/s390/kernel/swsusp_asm64.S
+++ b/arch/s390/kernel/swsusp_asm64.S
@@ -199,6 +199,7 @@ pgm_check_entry:
        brc     2,4b                    /* busy, try again */
 5:
        sigp    %r9,%r2,__SIGP_STOP     /* stop resume (current) CPU */
+       brc     2,5b                    /* busy, try again */
 6:     j       6b
 
 restart_suspend: