atomic: use <linux/atomic.h>
[linux-2.6.git] / 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 = PSW_BASE_BITS | PSW_MASK_WAIT;
34         quiesce_psw.addr = 0xfff;
35         __load_psw(quiesce_psw);
36 }
37
38 /* Handler for quiesce event. Start shutdown procedure. */
39 static void sclp_quiesce_handler(struct evbuf_header *evbuf)
40 {
41         if (_machine_restart != (void *) do_machine_quiesce) {
42                 old_machine_restart = _machine_restart;
43                 old_machine_halt = _machine_halt;
44                 old_machine_power_off = _machine_power_off;
45                 _machine_restart = (void *) do_machine_quiesce;
46                 _machine_halt = do_machine_quiesce;
47                 _machine_power_off = do_machine_quiesce;
48         }
49         ctrl_alt_del();
50 }
51
52 /* Undo machine restart/halt/power_off modification on resume */
53 static void sclp_quiesce_pm_event(struct sclp_register *reg,
54                                   enum sclp_pm_event sclp_pm_event)
55 {
56         switch (sclp_pm_event) {
57         case SCLP_PM_EVENT_RESTORE:
58                 if (old_machine_restart) {
59                         _machine_restart = old_machine_restart;
60                         _machine_halt = old_machine_halt;
61                         _machine_power_off = old_machine_power_off;
62                         old_machine_restart = NULL;
63                         old_machine_halt = NULL;
64                         old_machine_power_off = NULL;
65                 }
66                 break;
67         case SCLP_PM_EVENT_FREEZE:
68         case SCLP_PM_EVENT_THAW:
69                 break;
70         }
71 }
72
73 static struct sclp_register sclp_quiesce_event = {
74         .receive_mask = EVTYP_SIGQUIESCE_MASK,
75         .receiver_fn = sclp_quiesce_handler,
76         .pm_event_fn = sclp_quiesce_pm_event
77 };
78
79 /* Initialize quiesce driver. */
80 static int __init sclp_quiesce_init(void)
81 {
82         return sclp_register(&sclp_quiesce_event);
83 }
84
85 module_init(sclp_quiesce_init);