[S390] Dont overwrite lowcores on smp_send_stop().

Don't perform a sigp store-status-at-address on smp_send_stop().
It will overwrite the lowcores of other cpus and destroys valueable
debug informations.

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

1 files changed, 7 insertions, 49 deletions

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index b05ae8584258..264ea906db4c 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -193,72 +193,30 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 }
 EXPORT_SYMBOL(smp_call_function_single);
 
-static void do_send_stop(void)
+void smp_send_stop(void)
 {
         int cpu, rc;
 
-        /* stop all processors */
-        for_each_online_cpu(cpu) {
-                if (cpu == smp_processor_id())
-                        continue;
-                do {
-                        rc = signal_processor(cpu, sigp_stop);
-                } while (rc == sigp_busy);
-        }
-}
+        /* Disable all interrupts/machine checks */
+        __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
 
-static void do_store_status(void)
-{
-        int cpu, rc;
+        /* write magic number to zero page (absolute 0) */
+        lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
 
-        /* store status of all processors in their lowcores (real 0) */
+        /* stop all processors */
         for_each_online_cpu(cpu) {
                 if (cpu == smp_processor_id())
                         continue;
                 do {
-                        rc = signal_processor_p(
-                                (__u32)(unsigned long) lowcore_ptr[cpu], cpu,
-                                sigp_store_status_at_address);
+                        rc = signal_processor(cpu, sigp_stop);
                 } while (rc == sigp_busy);
-        }
-}
 
-static void do_wait_for_stop(void)
-{
-        int cpu;
-
-        /* Wait for all other cpus to enter stopped state */
-        for_each_online_cpu(cpu) {
-                if (cpu == smp_processor_id())
-                        continue;
                 while (!smp_cpu_not_running(cpu))
                         cpu_relax();
         }
 }
 
 /*
- * this function sends a 'stop' sigp to all other CPUs in the system.
- * it goes straight through.
- */
-void smp_send_stop(void)
-{
-        /* Disable all interrupts/machine checks */
-        __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
-
-        /* write magic number to zero page (absolute 0) */
-        lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
-
-        /* stop other processors. */
-        do_send_stop();
-
-        /* wait until other processors are stopped */
-        do_wait_for_stop();
-
-        /* store status of other processors. */
-        do_store_status();
-}
-
-/*
  * Reboot, halt and power_off routines for SMP.
  */
 void machine_restart_smp(char *__unused)