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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 | ||
770824bd RW |
42 | err = sysdev_suspend(PMSG_SUSPEND); |
43 | if (err) { | |
44 | printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n", | |
45 | err); | |
770824bd RW |
46 | return err; |
47 | } | |
359cdd3f | 48 | |
0e91398f JF |
49 | xen_mm_pin_all(); |
50 | gnttab_suspend(); | |
0e91398f JF |
51 | xen_pre_suspend(); |
52 | ||
53 | /* | |
54 | * This hypercall returns 1 if suspend was cancelled | |
55 | * or the domain was merely checkpointed, and 0 if it | |
56 | * is resuming in a new domain. | |
57 | */ | |
58 | *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); | |
59 | ||
60 | xen_post_suspend(*cancelled); | |
0e91398f JF |
61 | gnttab_resume(); |
62 | xen_mm_unpin_all(); | |
63 | ||
64 | if (!*cancelled) { | |
65 | xen_irq_resume(); | |
66 | xen_console_resume(); | |
ad55db9f | 67 | xen_timer_resume(); |
0e91398f JF |
68 | } |
69 | ||
1e6fcf84 | 70 | sysdev_resume(); |
1e6fcf84 | 71 | |
0e91398f JF |
72 | return 0; |
73 | } | |
74 | ||
75 | static void do_suspend(void) | |
76 | { | |
77 | int err; | |
78 | int cancelled = 1; | |
79 | ||
80 | shutting_down = SHUTDOWN_SUSPEND; | |
81 | ||
82 | #ifdef CONFIG_PREEMPT | |
83 | /* If the kernel is preemptible, we need to freeze all the processes | |
84 | to prevent them from being in the middle of a pagetable update | |
85 | during suspend. */ | |
86 | err = freeze_processes(); | |
87 | if (err) { | |
88 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
89 | return; | |
90 | } | |
91 | #endif | |
92 | ||
d1616302 | 93 | err = dpm_suspend_start(PMSG_SUSPEND); |
0e91398f | 94 | if (err) { |
d1616302 | 95 | printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); |
0e91398f JF |
96 | goto out; |
97 | } | |
98 | ||
de5b31bd IC |
99 | printk(KERN_DEBUG "suspending xenstore...\n"); |
100 | xs_suspend(); | |
0e91398f | 101 | |
d1616302 | 102 | err = dpm_suspend_noirq(PMSG_SUSPEND); |
2ed8d2b3 | 103 | if (err) { |
d1616302 | 104 | printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err); |
2ed8d2b3 RW |
105 | goto resume_devices; |
106 | } | |
107 | ||
f7df8ed1 | 108 | err = stop_machine(xen_suspend, &cancelled, cpumask_of(0)); |
922cc38a JF |
109 | |
110 | dpm_resume_noirq(PMSG_RESUME); | |
111 | ||
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(); | |
de5b31bd | 119 | xs_resume(); |
ad55db9f | 120 | } else |
de5b31bd | 121 | xs_suspend_cancel(); |
0e91398f | 122 | |
2ed8d2b3 | 123 | resume_devices: |
d1616302 | 124 | dpm_resume_end(PMSG_RESUME); |
0e91398f | 125 | |
359cdd3f JF |
126 | /* Make sure timer events get retriggered on all CPUs */ |
127 | clock_was_set(); | |
0e91398f JF |
128 | out: |
129 | #ifdef CONFIG_PREEMPT | |
130 | thaw_processes(); | |
131 | #endif | |
132 | shutting_down = SHUTDOWN_INVALID; | |
133 | } | |
c7827728 | 134 | #endif /* CONFIG_PM_SLEEP */ |
3e2b8fbe JF |
135 | |
136 | static void shutdown_handler(struct xenbus_watch *watch, | |
137 | const char **vec, unsigned int len) | |
138 | { | |
139 | char *str; | |
140 | struct xenbus_transaction xbt; | |
141 | int err; | |
142 | ||
143 | if (shutting_down != SHUTDOWN_INVALID) | |
144 | return; | |
145 | ||
146 | again: | |
147 | err = xenbus_transaction_start(&xbt); | |
148 | if (err) | |
149 | return; | |
150 | ||
151 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
152 | /* Ignore read errors and empty reads. */ | |
153 | if (XENBUS_IS_ERR_READ(str)) { | |
154 | xenbus_transaction_end(xbt, 1); | |
155 | return; | |
156 | } | |
157 | ||
158 | xenbus_write(xbt, "control", "shutdown", ""); | |
159 | ||
160 | err = xenbus_transaction_end(xbt, 0); | |
161 | if (err == -EAGAIN) { | |
162 | kfree(str); | |
163 | goto again; | |
164 | } | |
165 | ||
166 | if (strcmp(str, "poweroff") == 0 || | |
0e91398f JF |
167 | strcmp(str, "halt") == 0) { |
168 | shutting_down = SHUTDOWN_POWEROFF; | |
3e2b8fbe | 169 | orderly_poweroff(false); |
0e91398f JF |
170 | } else if (strcmp(str, "reboot") == 0) { |
171 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
3e2b8fbe | 172 | ctrl_alt_del(); |
0e91398f JF |
173 | #ifdef CONFIG_PM_SLEEP |
174 | } else if (strcmp(str, "suspend") == 0) { | |
175 | do_suspend(); | |
176 | #endif | |
177 | } else { | |
3e2b8fbe JF |
178 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
179 | shutting_down = SHUTDOWN_INVALID; | |
180 | } | |
181 | ||
182 | kfree(str); | |
183 | } | |
184 | ||
185 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, | |
186 | unsigned int len) | |
187 | { | |
188 | char sysrq_key = '\0'; | |
189 | struct xenbus_transaction xbt; | |
190 | int err; | |
191 | ||
192 | again: | |
193 | err = xenbus_transaction_start(&xbt); | |
194 | if (err) | |
195 | return; | |
196 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
197 | printk(KERN_ERR "Unable to read sysrq code in " | |
198 | "control/sysrq\n"); | |
199 | xenbus_transaction_end(xbt, 1); | |
200 | return; | |
201 | } | |
202 | ||
203 | if (sysrq_key != '\0') | |
204 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
205 | ||
206 | err = xenbus_transaction_end(xbt, 0); | |
207 | if (err == -EAGAIN) | |
208 | goto again; | |
209 | ||
210 | if (sysrq_key != '\0') | |
211 | handle_sysrq(sysrq_key, NULL); | |
212 | } | |
213 | ||
214 | static struct xenbus_watch shutdown_watch = { | |
215 | .node = "control/shutdown", | |
216 | .callback = shutdown_handler | |
217 | }; | |
218 | ||
219 | static struct xenbus_watch sysrq_watch = { | |
220 | .node = "control/sysrq", | |
221 | .callback = sysrq_handler | |
222 | }; | |
223 | ||
224 | static int setup_shutdown_watcher(void) | |
225 | { | |
226 | int err; | |
227 | ||
228 | err = register_xenbus_watch(&shutdown_watch); | |
229 | if (err) { | |
230 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
231 | return err; | |
232 | } | |
233 | ||
234 | err = register_xenbus_watch(&sysrq_watch); | |
235 | if (err) { | |
236 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
237 | return err; | |
238 | } | |
239 | ||
240 | return 0; | |
241 | } | |
242 | ||
243 | static int shutdown_event(struct notifier_block *notifier, | |
244 | unsigned long event, | |
245 | void *data) | |
246 | { | |
247 | setup_shutdown_watcher(); | |
248 | return NOTIFY_DONE; | |
249 | } | |
250 | ||
251 | static int __init setup_shutdown_event(void) | |
252 | { | |
253 | static struct notifier_block xenstore_notifier = { | |
254 | .notifier_call = shutdown_event | |
255 | }; | |
256 | register_xenstore_notifier(&xenstore_notifier); | |
257 | ||
258 | return 0; | |
259 | } | |
260 | ||
261 | subsys_initcall(setup_shutdown_event); |