drivers/s390/char/sclp_quiesce.c

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