| /* |
| * drivers/s390/char/sclp_quiesce.c |
| * signal quiesce handler |
| * |
| * (C) Copyright IBM Corp. 1999,2004 |
| * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> |
| * Peter Oberparleiter <peter.oberparleiter@de.ibm.com> |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/cpumask.h> |
| #include <linux/smp.h> |
| #include <linux/init.h> |
| #include <linux/reboot.h> |
| #include <asm/atomic.h> |
| #include <asm/ptrace.h> |
| #include <asm/sigp.h> |
| |
| #include "sclp.h" |
| |
| |
| #ifdef CONFIG_SMP |
| /* Signal completion of shutdown process. All CPUs except the first to enter |
| * this function: go to stopped state. First CPU: wait until all other |
| * CPUs are in stopped or check stop state. Afterwards, load special PSW |
| * to indicate completion. */ |
| static void |
| do_load_quiesce_psw(void * __unused) |
| { |
| static atomic_t cpuid = ATOMIC_INIT(-1); |
| psw_t quiesce_psw; |
| int cpu; |
| |
| 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(); |
| } |
| /* Quiesce the last cpu with the special psw */ |
| quiesce_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT; |
| quiesce_psw.addr = 0xfff; |
| __load_psw(quiesce_psw); |
| } |
| |
| /* Shutdown handler. Perform shutdown function on all CPUs. */ |
| static void |
| do_machine_quiesce(void) |
| { |
| on_each_cpu(do_load_quiesce_psw, NULL, 0, 0); |
| } |
| #else |
| /* Shutdown handler. Signal completion of shutdown by loading special PSW. */ |
| static void |
| do_machine_quiesce(void) |
| { |
| psw_t quiesce_psw; |
| |
| quiesce_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT; |
| quiesce_psw.addr = 0xfff; |
| __load_psw(quiesce_psw); |
| } |
| #endif |
| |
| /* Handler for quiesce event. Start shutdown procedure. */ |
| static void |
| sclp_quiesce_handler(struct evbuf_header *evbuf) |
| { |
| _machine_restart = (void *) do_machine_quiesce; |
| _machine_halt = do_machine_quiesce; |
| _machine_power_off = do_machine_quiesce; |
| ctrl_alt_del(); |
| } |
| |
| static struct sclp_register sclp_quiesce_event = { |
| .receive_mask = EvTyp_SigQuiesce_Mask, |
| .receiver_fn = sclp_quiesce_handler |
| }; |
| |
| /* Initialize quiesce driver. */ |
| static int __init |
| sclp_quiesce_init(void) |
| { |
| int rc; |
| |
| rc = sclp_register(&sclp_quiesce_event); |
| if (rc) |
| printk(KERN_WARNING "sclp: could not register quiesce handler " |
| "(rc=%d)\n", rc); |
| return rc; |
| } |
| |
| module_init(sclp_quiesce_init); |