diff options
Diffstat (limited to 'drivers/s390/char/sclp_quiesce.c')
-rw-r--r-- | drivers/s390/char/sclp_quiesce.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/drivers/s390/char/sclp_quiesce.c b/drivers/s390/char/sclp_quiesce.c new file mode 100644 index 000000000000..83f75774df60 --- /dev/null +++ b/drivers/s390/char/sclp_quiesce.c @@ -0,0 +1,99 @@ +/* + * 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 <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_compare_and_swap(-1, smp_processor_id(), &cpuid)) + 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 + +extern void ctrl_alt_del(void); + +/* 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); |