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 <asm/atomic.h>
  17 #include <asm/ptrace.h>
  18 #include <asm/sigp.h>
  19 #include <asm/smp.h>
  20
  21 #include "sclp.h"
  22
  23 /* Shutdown handler. Signal completion of shutdown by loading special PSW. */
  24 static void
  25 do_machine_quiesce(void)
  26 {
  27         psw_t quiesce_psw;
  28
  29         smp_send_stop();
  30         quiesce_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT;
  31         quiesce_psw.addr = 0xfff;
  32         __load_psw(quiesce_psw);
  33 }
  34
  35 /* Handler for quiesce event. Start shutdown procedure. */
  36 static void
  37 sclp_quiesce_handler(struct evbuf_header *evbuf)
  38 {
  39         _machine_restart = (void *) do_machine_quiesce;
  40         _machine_halt = do_machine_quiesce;
  41         _machine_power_off = do_machine_quiesce;
  42         ctrl_alt_del();
  43 }
  44
  45 static struct sclp_register sclp_quiesce_event = {
  46         .receive_mask = EVTYP_SIGQUIESCE_MASK,
  47         .receiver_fn = sclp_quiesce_handler
  48 };
  49
  50 /* Initialize quiesce driver. */
  51 static int __init
  52 sclp_quiesce_init(void)
  53 {
  54         int rc;
  55
  56         rc = sclp_register(&sclp_quiesce_event);
  57         if (rc)
  58                 printk(KERN_WARNING "sclp: could not register quiesce handler "
  59                        "(rc=%d)\n", rc);
  60         return rc;
  61 }
  62
  63 module_init(sclp_quiesce_init);