xref: /openbmc/linux/arch/sparc/kernel/sstate.c (revision f39650de)
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 
21 static int hv_supports_soft_state;
22 
do_set_sstate(unsigned long state,const char * msg)23 static 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 
38 static const char booting_msg[32] __attribute__((aligned(32))) =
39 	"Linux booting";
40 static const char running_msg[32] __attribute__((aligned(32))) =
41 	"Linux running";
42 static const char halting_msg[32] __attribute__((aligned(32))) =
43 	"Linux halting";
44 static const char poweroff_msg[32] __attribute__((aligned(32))) =
45 	"Linux powering off";
46 static const char rebooting_msg[32] __attribute__((aligned(32))) =
47 	"Linux rebooting";
48 static const char panicking_msg[32] __attribute__((aligned(32))) =
49 	"Linux panicking";
50 
sstate_reboot_call(struct notifier_block * np,unsigned long type,void * _unused)51 static 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 
75 static struct notifier_block sstate_reboot_notifier = {
76 	.notifier_call = sstate_reboot_call,
77 };
78 
sstate_panic_event(struct notifier_block * n,unsigned long event,void * ptr)79 static 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 
86 static struct notifier_block sstate_panic_block = {
87 	.notifier_call	=	sstate_panic_event,
88 	.priority	=	INT_MAX,
89 };
90 
sstate_init(void)91 static 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 
116 core_initcall(sstate_init);
117 
sstate_running(void)118 static int __init sstate_running(void)
119 {
120 	do_set_sstate(HV_SOFT_STATE_NORMAL, running_msg);
121 	return 0;
122 }
123 
124 late_initcall(sstate_running);
125