xref: /openbmc/linux/drivers/s390/char/sclp_quiesce.c (revision 22246614)
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);
64