drivers/s390/char/sclp_quiesce.c

   1 /*
   2  *  drivers/s390/char/sclp_quiesce.c
   3  *     signal quiesce handler
   4  *
   5  *  (C) Copyright IBM Corp. 1999,2004
   6  *  Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  *             Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/types.h>
  12 #include <linux/cpumask.h>
  13 #include <linux/smp.h>
  14 #include <linux/init.h>
  15 #include <linux/reboot.h>
  16 #include <linux/atomic.h>
  17 #include <asm/ptrace.h>
  18 #include <asm/sigp.h>
  19 #include <asm/smp.h>
  20
  21 #include "sclp.h"
  22
  23 static void (*old_machine_restart)(char *);
  24 static void (*old_machine_halt)(void);
  25 static void (*old_machine_power_off)(void);
  26
  27 /* Shutdown handler. Signal completion of shutdown by loading special PSW. */
  28 static void do_machine_quiesce(void)
  29 {
  30         psw_t quiesce_psw;
  31
  32         smp_send_stop();
  33         quiesce_psw.mask =
  34                 PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA | PSW_MASK_WAIT;
  35         quiesce_psw.addr = 0xfff;
  36         __load_psw(quiesce_psw);
  37 }
  38
  39 /* Handler for quiesce event. Start shutdown procedure. */
  40 static void sclp_quiesce_handler(struct evbuf_header *evbuf)
  41 {
  42         if (_machine_restart != (void *) do_machine_quiesce) {
  43                 old_machine_restart = _machine_restart;
  44                 old_machine_halt = _machine_halt;
  45                 old_machine_power_off = _machine_power_off;
  46                 _machine_restart = (void *) do_machine_quiesce;
  47                 _machine_halt = do_machine_quiesce;
  48                 _machine_power_off = do_machine_quiesce;
  49         }
  50         ctrl_alt_del();
  51 }
  52
  53 /* Undo machine restart/halt/power_off modification on resume */
  54 static void sclp_quiesce_pm_event(struct sclp_register *reg,
  55                                   enum sclp_pm_event sclp_pm_event)
  56 {
  57         switch (sclp_pm_event) {
  58         case SCLP_PM_EVENT_RESTORE:
  59                 if (old_machine_restart) {
  60                         _machine_restart = old_machine_restart;
  61                         _machine_halt = old_machine_halt;
  62                         _machine_power_off = old_machine_power_off;
  63                         old_machine_restart = NULL;
  64                         old_machine_halt = NULL;
  65                         old_machine_power_off = NULL;
  66                 }
  67                 break;
  68         case SCLP_PM_EVENT_FREEZE:
  69         case SCLP_PM_EVENT_THAW:
  70                 break;
  71         }
  72 }
  73
  74 static struct sclp_register sclp_quiesce_event = {
  75         .receive_mask = EVTYP_SIGQUIESCE_MASK,
  76         .receiver_fn = sclp_quiesce_handler,
  77         .pm_event_fn = sclp_quiesce_pm_event
  78 };
  79
  80 /* Initialize quiesce driver. */
  81 static int __init sclp_quiesce_init(void)
  82 {
  83         return sclp_register(&sclp_quiesce_event);
  84 }
  85
  86 module_init(sclp_quiesce_init);