Linux Kernel  3.7.1
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sstate.c
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1 /* sstate.c: System soft state support.
2  *
3  * Copyright (C) 2007, 2008 David S. Miller <[email protected]>
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 
19 static int hv_supports_soft_state;
20 
21 static 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 
36 static const char booting_msg[32] __attribute__((aligned(32))) =
37  "Linux booting";
38 static const char running_msg[32] __attribute__((aligned(32))) =
39  "Linux running";
40 static const char halting_msg[32] __attribute__((aligned(32))) =
41  "Linux halting";
42 static const char poweroff_msg[32] __attribute__((aligned(32))) =
43  "Linux powering off";
44 static const char rebooting_msg[32] __attribute__((aligned(32))) =
45  "Linux rebooting";
46 static const char panicing_msg[32] __attribute__((aligned(32))) =
47  "Linux panicing";
48 
49 static 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 
73 static struct notifier_block sstate_reboot_notifier = {
74  .notifier_call = sstate_reboot_call,
75 };
76 
77 static 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 
84 static struct notifier_block sstate_panic_block = {
85  .notifier_call = sstate_panic_event,
86  .priority = INT_MAX,
87 };
88 
89 static 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 
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 
114 core_initcall(sstate_init);
115 
116 static int __init sstate_running(void)
117 {
118  do_set_sstate(HV_SOFT_STATE_NORMAL, running_msg);
119  return 0;
120 }
121 
122 late_initcall(sstate_running);