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kernel/linux-rt-4.4.41/drivers/s390/char/sclp_quiesce.c 2.15 KB
5113f6f70   김현기   kernel add
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  /*
   *     signal quiesce handler
   *
   *  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 <linux/atomic.h>
  #include <asm/ptrace.h>
  #include <asm/smp.h>
  
  #include "sclp.h"
  
  static void (*old_machine_restart)(char *);
  static void (*old_machine_halt)(void);
  static void (*old_machine_power_off)(void);
  
  /* Shutdown handler. Signal completion of shutdown by loading special PSW. */
  static void do_machine_quiesce(void)
  {
  	psw_t quiesce_psw;
  
  	smp_send_stop();
  	quiesce_psw.mask =
  		PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA | PSW_MASK_WAIT;
  	quiesce_psw.addr = 0xfff;
  	__load_psw(quiesce_psw);
  }
  
  /* Handler for quiesce event. Start shutdown procedure. */
  static void sclp_quiesce_handler(struct evbuf_header *evbuf)
  {
  	if (_machine_restart != (void *) do_machine_quiesce) {
  		old_machine_restart = _machine_restart;
  		old_machine_halt = _machine_halt;
  		old_machine_power_off = _machine_power_off;
  		_machine_restart = (void *) do_machine_quiesce;
  		_machine_halt = do_machine_quiesce;
  		_machine_power_off = do_machine_quiesce;
  	}
  	ctrl_alt_del();
  }
  
  /* Undo machine restart/halt/power_off modification on resume */
  static void sclp_quiesce_pm_event(struct sclp_register *reg,
  				  enum sclp_pm_event sclp_pm_event)
  {
  	switch (sclp_pm_event) {
  	case SCLP_PM_EVENT_RESTORE:
  		if (old_machine_restart) {
  			_machine_restart = old_machine_restart;
  			_machine_halt = old_machine_halt;
  			_machine_power_off = old_machine_power_off;
  			old_machine_restart = NULL;
  			old_machine_halt = NULL;
  			old_machine_power_off = NULL;
  		}
  		break;
  	case SCLP_PM_EVENT_FREEZE:
  	case SCLP_PM_EVENT_THAW:
  		break;
  	}
  }
  
  static struct sclp_register sclp_quiesce_event = {
  	.receive_mask = EVTYP_SIGQUIESCE_MASK,
  	.receiver_fn = sclp_quiesce_handler,
  	.pm_event_fn = sclp_quiesce_pm_event
  };
  
  /* Initialize quiesce driver. */
  static int __init sclp_quiesce_init(void)
  {
  	return sclp_register(&sclp_quiesce_event);
  }
  
  module_init(sclp_quiesce_init);