[S390] cpu shutdown rework

Let one master cpu kill all other cpus instead of sending an external
interrupt to all other cpus so they can kill themselves.
Simplifies reipl/shutdown functions a lot.

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

1 files changed, 31 insertions, 73 deletions

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 62822245f9be..b549a43ed08f 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -230,18 +230,37 @@ static inline void do_store_status(void)
         }
 }
 
+static inline 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();
 }
@@ -250,88 +269,28 @@ void smp_send_stop(void)
  * Reboot, halt and power_off routines for SMP.
  */
 
-static void do_machine_restart(void * __unused)
-{
-        int cpu;
-        static atomic_t cpuid = ATOMIC_INIT(-1);
-
-        if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) != -1)
-                signal_processor(smp_processor_id(), sigp_stop);
-
-        /* 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();
-        }
-
-        /* Store status of other cpus. */
-        do_store_status();
-
-        /*
-         * Finally call reipl. Because we waited for all other
-         * cpus to enter this function we know that they do
-         * not hold any s390irq-locks (the cpus have been
-         * interrupted by an external interrupt and s390irq
-         * locks are always held disabled).
-         */
-        do_reipl();
-}
-
 void machine_restart_smp(char * __unused) 
 {
-        on_each_cpu(do_machine_restart, NULL, 0, 0);
-}
-
-static void do_wait_for_stop(void)
-{
-        unsigned long cr[16];
-
-        __ctl_store(cr, 0, 15);
-        cr[0] &= ~0xffff;
-        cr[6] = 0;
-        __ctl_load(cr, 0, 15);
-        for (;;)
-                enabled_wait();
-}
-
-static void do_machine_halt(void * __unused)
-{
-        static atomic_t cpuid = ATOMIC_INIT(-1);
-
-        if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) == -1) {
-                smp_send_stop();
-                if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
-                        cpcmd(vmhalt_cmd, NULL, 0, NULL);
-                signal_processor(smp_processor_id(),
-                                 sigp_stop_and_store_status);
-        }
-        do_wait_for_stop();
+        smp_send_stop();
+        do_reipl();
 }
 
 void machine_halt_smp(void)
 {
-        on_each_cpu(do_machine_halt, NULL, 0, 0);
-}
-
-static void do_machine_power_off(void * __unused)
-{
-        static atomic_t cpuid = ATOMIC_INIT(-1);
-
-        if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) == -1) {
-                smp_send_stop();
-                if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
-                        cpcmd(vmpoff_cmd, NULL, 0, NULL);
-                signal_processor(smp_processor_id(),
-                                 sigp_stop_and_store_status);
-        }
-        do_wait_for_stop();
+        smp_send_stop();
+        if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
+                __cpcmd(vmhalt_cmd, NULL, 0, NULL);
+        signal_processor(smp_processor_id(), sigp_stop_and_store_status);
+        for (;;);
 }
 
 void machine_power_off_smp(void)
 {
-        on_each_cpu(do_machine_power_off, NULL, 0, 0);
+        smp_send_stop();
+        if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
+                __cpcmd(vmpoff_cmd, NULL, 0, NULL);
+        signal_processor(smp_processor_id(), sigp_stop_and_store_status);
+        for (;;);
 }
 
 /*
@@ -860,4 +819,3 @@ EXPORT_SYMBOL(smp_ctl_clear_bit);
 EXPORT_SYMBOL(smp_call_function);
 EXPORT_SYMBOL(smp_get_cpu);
 EXPORT_SYMBOL(smp_put_cpu);
-