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