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
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
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
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
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
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
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