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Commit | Line | Data |
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3e2b8fbe JF |
1 | /* |
2 | * Handle extern requests for shutdown, reboot and sysrq | |
3 | */ | |
4 | #include <linux/kernel.h> | |
5 | #include <linux/err.h> | |
6 | #include <linux/reboot.h> | |
7 | #include <linux/sysrq.h> | |
0e91398f JF |
8 | #include <linux/stop_machine.h> |
9 | #include <linux/freezer.h> | |
3e2b8fbe JF |
10 | |
11 | #include <xen/xenbus.h> | |
0e91398f JF |
12 | #include <xen/grant_table.h> |
13 | #include <xen/events.h> | |
14 | #include <xen/hvc-console.h> | |
15 | #include <xen/xen-ops.h> | |
3e2b8fbe | 16 | |
0e91398f JF |
17 | #include <asm/xen/hypercall.h> |
18 | #include <asm/xen/page.h> | |
19 | ||
20 | enum shutdown_state { | |
21 | SHUTDOWN_INVALID = -1, | |
22 | SHUTDOWN_POWEROFF = 0, | |
23 | SHUTDOWN_SUSPEND = 2, | |
24 | /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only | |
25 | report a crash, not be instructed to crash! | |
26 | HALT is the same as POWEROFF, as far as we're concerned. The tools use | |
27 | the distinction when we return the reason code to them. */ | |
28 | SHUTDOWN_HALT = 4, | |
29 | }; | |
3e2b8fbe JF |
30 | |
31 | /* Ignore multiple shutdown requests. */ | |
0e91398f JF |
32 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
33 | ||
c7827728 | 34 | #ifdef CONFIG_PM_SLEEP |
0e91398f JF |
35 | static int xen_suspend(void *data) |
36 | { | |
37 | int *cancelled = data; | |
359cdd3f | 38 | int err; |
0e91398f JF |
39 | |
40 | BUG_ON(!irqs_disabled()); | |
41 | ||
359cdd3f JF |
42 | err = device_power_down(PMSG_SUSPEND); |
43 | if (err) { | |
44 | printk(KERN_ERR "xen_suspend: device_power_down failed: %d\n", | |
45 | err); | |
46 | return err; | |
47 | } | |
770824bd RW |
48 | err = sysdev_suspend(PMSG_SUSPEND); |
49 | if (err) { | |
50 | printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n", | |
51 | err); | |
52 | device_power_up(PMSG_RESUME); | |
53 | return err; | |
54 | } | |
359cdd3f | 55 | |
0e91398f JF |
56 | xen_mm_pin_all(); |
57 | gnttab_suspend(); | |
0e91398f JF |
58 | xen_pre_suspend(); |
59 | ||
60 | /* | |
61 | * This hypercall returns 1 if suspend was cancelled | |
62 | * or the domain was merely checkpointed, and 0 if it | |
63 | * is resuming in a new domain. | |
64 | */ | |
65 | *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); | |
66 | ||
67 | xen_post_suspend(*cancelled); | |
0e91398f JF |
68 | gnttab_resume(); |
69 | xen_mm_unpin_all(); | |
70 | ||
770824bd | 71 | sysdev_resume(); |
55ca089e | 72 | device_power_up(PMSG_RESUME); |
359cdd3f | 73 | |
0e91398f JF |
74 | if (!*cancelled) { |
75 | xen_irq_resume(); | |
76 | xen_console_resume(); | |
ad55db9f | 77 | xen_timer_resume(); |
0e91398f JF |
78 | } |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | static void do_suspend(void) | |
84 | { | |
85 | int err; | |
86 | int cancelled = 1; | |
87 | ||
88 | shutting_down = SHUTDOWN_SUSPEND; | |
89 | ||
90 | #ifdef CONFIG_PREEMPT | |
91 | /* If the kernel is preemptible, we need to freeze all the processes | |
92 | to prevent them from being in the middle of a pagetable update | |
93 | during suspend. */ | |
94 | err = freeze_processes(); | |
95 | if (err) { | |
96 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
97 | return; | |
98 | } | |
99 | #endif | |
100 | ||
101 | err = device_suspend(PMSG_SUSPEND); | |
102 | if (err) { | |
103 | printk(KERN_ERR "xen suspend: device_suspend %d\n", err); | |
104 | goto out; | |
105 | } | |
106 | ||
107 | printk("suspending xenbus...\n"); | |
108 | /* XXX use normal device tree? */ | |
109 | xenbus_suspend(); | |
110 | ||
f7df8ed1 | 111 | err = stop_machine(xen_suspend, &cancelled, cpumask_of(0)); |
0e91398f JF |
112 | if (err) { |
113 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); | |
114 | goto out; | |
115 | } | |
116 | ||
ad55db9f IY |
117 | if (!cancelled) { |
118 | xen_arch_resume(); | |
0e91398f | 119 | xenbus_resume(); |
ad55db9f | 120 | } else |
0e91398f JF |
121 | xenbus_suspend_cancel(); |
122 | ||
55ca089e | 123 | device_resume(PMSG_RESUME); |
0e91398f | 124 | |
359cdd3f JF |
125 | /* Make sure timer events get retriggered on all CPUs */ |
126 | clock_was_set(); | |
0e91398f JF |
127 | out: |
128 | #ifdef CONFIG_PREEMPT | |
129 | thaw_processes(); | |
130 | #endif | |
131 | shutting_down = SHUTDOWN_INVALID; | |
132 | } | |
c7827728 | 133 | #endif /* CONFIG_PM_SLEEP */ |
3e2b8fbe JF |
134 | |
135 | static void shutdown_handler(struct xenbus_watch *watch, | |
136 | const char **vec, unsigned int len) | |
137 | { | |
138 | char *str; | |
139 | struct xenbus_transaction xbt; | |
140 | int err; | |
141 | ||
142 | if (shutting_down != SHUTDOWN_INVALID) | |
143 | return; | |
144 | ||
145 | again: | |
146 | err = xenbus_transaction_start(&xbt); | |
147 | if (err) | |
148 | return; | |
149 | ||
150 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
151 | /* Ignore read errors and empty reads. */ | |
152 | if (XENBUS_IS_ERR_READ(str)) { | |
153 | xenbus_transaction_end(xbt, 1); | |
154 | return; | |
155 | } | |
156 | ||
157 | xenbus_write(xbt, "control", "shutdown", ""); | |
158 | ||
159 | err = xenbus_transaction_end(xbt, 0); | |
160 | if (err == -EAGAIN) { | |
161 | kfree(str); | |
162 | goto again; | |
163 | } | |
164 | ||
165 | if (strcmp(str, "poweroff") == 0 || | |
0e91398f JF |
166 | strcmp(str, "halt") == 0) { |
167 | shutting_down = SHUTDOWN_POWEROFF; | |
3e2b8fbe | 168 | orderly_poweroff(false); |
0e91398f JF |
169 | } else if (strcmp(str, "reboot") == 0) { |
170 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
3e2b8fbe | 171 | ctrl_alt_del(); |
0e91398f JF |
172 | #ifdef CONFIG_PM_SLEEP |
173 | } else if (strcmp(str, "suspend") == 0) { | |
174 | do_suspend(); | |
175 | #endif | |
176 | } else { | |
3e2b8fbe JF |
177 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
178 | shutting_down = SHUTDOWN_INVALID; | |
179 | } | |
180 | ||
181 | kfree(str); | |
182 | } | |
183 | ||
184 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, | |
185 | unsigned int len) | |
186 | { | |
187 | char sysrq_key = '\0'; | |
188 | struct xenbus_transaction xbt; | |
189 | int err; | |
190 | ||
191 | again: | |
192 | err = xenbus_transaction_start(&xbt); | |
193 | if (err) | |
194 | return; | |
195 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
196 | printk(KERN_ERR "Unable to read sysrq code in " | |
197 | "control/sysrq\n"); | |
198 | xenbus_transaction_end(xbt, 1); | |
199 | return; | |
200 | } | |
201 | ||
202 | if (sysrq_key != '\0') | |
203 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
204 | ||
205 | err = xenbus_transaction_end(xbt, 0); | |
206 | if (err == -EAGAIN) | |
207 | goto again; | |
208 | ||
209 | if (sysrq_key != '\0') | |
210 | handle_sysrq(sysrq_key, NULL); | |
211 | } | |
212 | ||
213 | static struct xenbus_watch shutdown_watch = { | |
214 | .node = "control/shutdown", | |
215 | .callback = shutdown_handler | |
216 | }; | |
217 | ||
218 | static struct xenbus_watch sysrq_watch = { | |
219 | .node = "control/sysrq", | |
220 | .callback = sysrq_handler | |
221 | }; | |
222 | ||
223 | static int setup_shutdown_watcher(void) | |
224 | { | |
225 | int err; | |
226 | ||
227 | err = register_xenbus_watch(&shutdown_watch); | |
228 | if (err) { | |
229 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
230 | return err; | |
231 | } | |
232 | ||
233 | err = register_xenbus_watch(&sysrq_watch); | |
234 | if (err) { | |
235 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
236 | return err; | |
237 | } | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
242 | static int shutdown_event(struct notifier_block *notifier, | |
243 | unsigned long event, | |
244 | void *data) | |
245 | { | |
246 | setup_shutdown_watcher(); | |
247 | return NOTIFY_DONE; | |
248 | } | |
249 | ||
250 | static int __init setup_shutdown_event(void) | |
251 | { | |
252 | static struct notifier_block xenstore_notifier = { | |
253 | .notifier_call = shutdown_event | |
254 | }; | |
255 | register_xenstore_notifier(&xenstore_notifier); | |
256 | ||
257 | return 0; | |
258 | } | |
259 | ||
260 | subsys_initcall(setup_shutdown_event); |