[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>
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 6282224..b549a43 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -230,18 +230,37 @@
}
}
+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 @@
* 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_call_function);
EXPORT_SYMBOL(smp_get_cpu);
EXPORT_SYMBOL(smp_put_cpu);
-
