1// SPDX-License-Identifier: GPL-2.0
2/* sstate.c: System soft state support.
3 *
4 * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
5 */
6
7#include <linux/kernel.h>
8#include <linux/notifier.h>
9#include <linux/panic_notifier.h>
10#include <linux/reboot.h>
11#include <linux/init.h>
12
13#include <asm/hypervisor.h>
14#include <asm/spitfire.h>
15#include <asm/oplib.h>
16#include <asm/head.h>
17#include <asm/io.h>
18
19#include "kernel.h"
20
21static int hv_supports_soft_state;
22
23static void do_set_sstate(unsigned long state, const char *msg)
24{
25	unsigned long err;
26
27	if (!hv_supports_soft_state)
28		return;
29
30	err = sun4v_mach_set_soft_state(state, kimage_addr_to_ra(msg));
31	if (err) {
32		printk(KERN_WARNING "SSTATE: Failed to set soft-state to "
33		       "state[%lx] msg[%s], err=%lu\n",
34		       state, msg, err);
35	}
36}
37
38static const char booting_msg[32] __attribute__((aligned(32))) =
39	"Linux booting";
40static const char running_msg[32] __attribute__((aligned(32))) =
41	"Linux running";
42static const char halting_msg[32] __attribute__((aligned(32))) =
43	"Linux halting";
44static const char poweroff_msg[32] __attribute__((aligned(32))) =
45	"Linux powering off";
46static const char rebooting_msg[32] __attribute__((aligned(32))) =
47	"Linux rebooting";
48static const char panicking_msg[32] __attribute__((aligned(32))) =
49	"Linux panicking";
50
51static int sstate_reboot_call(struct notifier_block *np, unsigned long type, void *_unused)
52{
53	const char *msg;
54
55	switch (type) {
56	case SYS_DOWN:
57	default:
58		msg = rebooting_msg;
59		break;
60
61	case SYS_HALT:
62		msg = halting_msg;
63		break;
64
65	case SYS_POWER_OFF:
66		msg = poweroff_msg;
67		break;
68	}
69
70	do_set_sstate(HV_SOFT_STATE_TRANSITION, msg);
71
72	return NOTIFY_OK;
73}
74
75static struct notifier_block sstate_reboot_notifier = {
76	.notifier_call = sstate_reboot_call,
77};
78
79static int sstate_panic_event(struct notifier_block *n, unsigned long event, void *ptr)
80{
81	do_set_sstate(HV_SOFT_STATE_TRANSITION, panicking_msg);
82
83	return NOTIFY_DONE;
84}
85
86static struct notifier_block sstate_panic_block = {
87	.notifier_call	=	sstate_panic_event,
88	.priority	=	INT_MAX,
89};
90
91static int __init sstate_init(void)
92{
93	unsigned long major, minor;
94
95	if (tlb_type != hypervisor)
96		return 0;
97
98	major = 1;
99	minor = 0;
100	if (sun4v_hvapi_register(HV_GRP_SOFT_STATE, major, &minor))
101		return 0;
102
103	hv_supports_soft_state = 1;
104
105	prom_sun4v_guest_soft_state();
106
107	do_set_sstate(HV_SOFT_STATE_TRANSITION, booting_msg);
108
109	atomic_notifier_chain_register(&panic_notifier_list,
110				       &sstate_panic_block);
111	register_reboot_notifier(&sstate_reboot_notifier);
112
113	return 0;
114}
115
116core_initcall(sstate_init);
117
118static int __init sstate_running(void)
119{
120	do_set_sstate(HV_SOFT_STATE_NORMAL, running_msg);
121	return 0;
122}
123
124late_initcall(sstate_running);
125