1/* sstate.c: System soft state support.
2 *
3 * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
4 */
5
6#include <linux/kernel.h>
7#include <linux/notifier.h>
8#include <linux/reboot.h>
9#include <linux/init.h>
10
11#include <asm/hypervisor.h>
12#include <asm/spitfire.h>
13#include <asm/oplib.h>
14#include <asm/head.h>
15#include <asm/io.h>
16
17#include "kernel.h"
18
19static int hv_supports_soft_state;
20
21static void do_set_sstate(unsigned long state, const char *msg)
22{
23	unsigned long err;
24
25	if (!hv_supports_soft_state)
26		return;
27
28	err = sun4v_mach_set_soft_state(state, kimage_addr_to_ra(msg));
29	if (err) {
30		printk(KERN_WARNING "SSTATE: Failed to set soft-state to "
31		       "state[%lx] msg[%s], err=%lu\n",
32		       state, msg, err);
33	}
34}
35
36static const char booting_msg[32] __attribute__((aligned(32))) =
37	"Linux booting";
38static const char running_msg[32] __attribute__((aligned(32))) =
39	"Linux running";
40static const char halting_msg[32] __attribute__((aligned(32))) =
41	"Linux halting";
42static const char poweroff_msg[32] __attribute__((aligned(32))) =
43	"Linux powering off";
44static const char rebooting_msg[32] __attribute__((aligned(32))) =
45	"Linux rebooting";
46static const char panicing_msg[32] __attribute__((aligned(32))) =
47	"Linux panicing";
48
49static int sstate_reboot_call(struct notifier_block *np, unsigned long type, void *_unused)
50{
51	const char *msg;
52
53	switch (type) {
54	case SYS_DOWN:
55	default:
56		msg = rebooting_msg;
57		break;
58
59	case SYS_HALT:
60		msg = halting_msg;
61		break;
62
63	case SYS_POWER_OFF:
64		msg = poweroff_msg;
65		break;
66	}
67
68	do_set_sstate(HV_SOFT_STATE_TRANSITION, msg);
69
70	return NOTIFY_OK;
71}
72
73static struct notifier_block sstate_reboot_notifier = {
74	.notifier_call = sstate_reboot_call,
75};
76
77static int sstate_panic_event(struct notifier_block *n, unsigned long event, void *ptr)
78{
79	do_set_sstate(HV_SOFT_STATE_TRANSITION, panicing_msg);
80
81	return NOTIFY_DONE;
82}
83
84static struct notifier_block sstate_panic_block = {
85	.notifier_call	=	sstate_panic_event,
86	.priority	=	INT_MAX,
87};
88
89static int __init sstate_init(void)
90{
91	unsigned long major, minor;
92
93	if (tlb_type != hypervisor)
94		return 0;
95
96	major = 1;
97	minor = 0;
98	if (sun4v_hvapi_register(HV_GRP_SOFT_STATE, major, &minor))
99		return 0;
100
101	hv_supports_soft_state = 1;
102
103	prom_sun4v_guest_soft_state();
104
105	do_set_sstate(HV_SOFT_STATE_TRANSITION, booting_msg);
106
107	atomic_notifier_chain_register(&panic_notifier_list,
108				       &sstate_panic_block);
109	register_reboot_notifier(&sstate_reboot_notifier);
110
111	return 0;
112}
113
114core_initcall(sstate_init);
115
116static int __init sstate_running(void)
117{
118	do_set_sstate(HV_SOFT_STATE_NORMAL, running_msg);
119	return 0;
120}
121
122late_initcall(sstate_running);
123