LXR linux/drivers/s390/char/sclp

   1/*
   2 *     signal quiesce handler
   3 *
   4 *  Copyright IBM Corp. 1999, 2004
   5 *  Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   6 *             Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   7 */
   8
   9#include <linux/module.h>
  10#include <linux/types.h>
  11#include <linux/cpumask.h>
  12#include <linux/smp.h>
  13#include <linux/init.h>
  14#include <linux/reboot.h>
  15#include <linux/atomic.h>
  16#include <asm/ptrace.h>
  17#include <asm/smp.h>
  18
  19#include "sclp.h"
  20
  21static void (*old_machine_restart)(char *);
  22static void (*old_machine_halt)(void);
  23static void (*old_machine_power_off)(void);
  24
  25/* Shutdown handler. Signal completion of shutdown by loading special PSW. */
  26static void do_machine_quiesce(void)
  27{
  28        psw_t quiesce_psw;
  29
  30        smp_send_stop();
  31        quiesce_psw.mask =
  32                PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA | PSW_MASK_WAIT;
  33        quiesce_psw.addr = 0xfff;
  34        __load_psw(quiesce_psw);
  35}
  36
  37/* Handler for quiesce event. Start shutdown procedure. */
  38static void sclp_quiesce_handler(struct evbuf_header *evbuf)
  39{
  40        if (_machine_restart != (void *) do_machine_quiesce) {
  41                old_machine_restart = _machine_restart;
  42                old_machine_halt = _machine_halt;
  43                old_machine_power_off = _machine_power_off;
  44                _machine_restart = (void *) do_machine_quiesce;
  45                _machine_halt = do_machine_quiesce;
  46                _machine_power_off = do_machine_quiesce;
  47        }
  48        ctrl_alt_del();
  49}
  50
  51/* Undo machine restart/halt/power_off modification on resume */
  52static void sclp_quiesce_pm_event(struct sclp_register *reg,
  53                                  enum sclp_pm_event sclp_pm_event)
  54{
  55        switch (sclp_pm_event) {
  56        case SCLP_PM_EVENT_RESTORE:
  57                if (old_machine_restart) {
  58                        _machine_restart = old_machine_restart;
  59                        _machine_halt = old_machine_halt;
  60                        _machine_power_off = old_machine_power_off;
  61                        old_machine_restart = NULL;
  62                        old_machine_halt = NULL;
  63                        old_machine_power_off = NULL;
  64                }
  65                break;
  66        case SCLP_PM_EVENT_FREEZE:
  67        case SCLP_PM_EVENT_THAW:
  68                break;
  69        }
  70}
  71
  72static struct sclp_register sclp_quiesce_event = {
  73        .receive_mask = EVTYP_SIGQUIESCE_MASK,
  74        .receiver_fn = sclp_quiesce_handler,
  75        .pm_event_fn = sclp_quiesce_pm_event
  76};
  77
  78/* Initialize quiesce driver. */
  79static int __init sclp_quiesce_init(void)
  80{
  81        return sclp_register(&sclp_quiesce_event);
  82}
  83
  84module_init(sclp_quiesce_init);
  85