/* * 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/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);