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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> | |
5a0e3ad6 | 6 | #include <linux/slab.h> |
3e2b8fbe JF |
7 | #include <linux/reboot.h> |
8 | #include <linux/sysrq.h> | |
0e91398f JF |
9 | #include <linux/stop_machine.h> |
10 | #include <linux/freezer.h> | |
19234c08 | 11 | #include <linux/syscore_ops.h> |
3e2b8fbe | 12 | |
016b6f5f | 13 | #include <xen/xen.h> |
3e2b8fbe | 14 | #include <xen/xenbus.h> |
0e91398f JF |
15 | #include <xen/grant_table.h> |
16 | #include <xen/events.h> | |
17 | #include <xen/hvc-console.h> | |
18 | #include <xen/xen-ops.h> | |
3e2b8fbe | 19 | |
0e91398f JF |
20 | #include <asm/xen/hypercall.h> |
21 | #include <asm/xen/page.h> | |
016b6f5f | 22 | #include <asm/xen/hypervisor.h> |
0e91398f JF |
23 | |
24 | enum shutdown_state { | |
25 | SHUTDOWN_INVALID = -1, | |
26 | SHUTDOWN_POWEROFF = 0, | |
27 | SHUTDOWN_SUSPEND = 2, | |
28 | /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only | |
29 | report a crash, not be instructed to crash! | |
30 | HALT is the same as POWEROFF, as far as we're concerned. The tools use | |
31 | the distinction when we return the reason code to them. */ | |
32 | SHUTDOWN_HALT = 4, | |
33 | }; | |
3e2b8fbe JF |
34 | |
35 | /* Ignore multiple shutdown requests. */ | |
0e91398f JF |
36 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
37 | ||
ceb18029 IC |
38 | struct suspend_info { |
39 | int cancelled; | |
36b401e2 | 40 | unsigned long arg; /* extra hypercall argument */ |
55fb4ace IC |
41 | void (*pre)(void); |
42 | void (*post)(int cancelled); | |
ceb18029 IC |
43 | }; |
44 | ||
07af3810 | 45 | static void xen_hvm_post_suspend(int cancelled) |
82043bb6 | 46 | { |
07af3810 | 47 | xen_arch_hvm_post_suspend(cancelled); |
82043bb6 IC |
48 | gnttab_resume(); |
49 | } | |
50 | ||
51 | static void xen_pre_suspend(void) | |
52 | { | |
53 | xen_mm_pin_all(); | |
54 | gnttab_suspend(); | |
07af3810 | 55 | xen_arch_pre_suspend(); |
82043bb6 IC |
56 | } |
57 | ||
07af3810 | 58 | static void xen_post_suspend(int cancelled) |
82043bb6 | 59 | { |
07af3810 | 60 | xen_arch_post_suspend(cancelled); |
82043bb6 IC |
61 | gnttab_resume(); |
62 | xen_mm_unpin_all(); | |
63 | } | |
64 | ||
1f112cee | 65 | #ifdef CONFIG_HIBERNATE_CALLBACKS |
016b6f5f SS |
66 | static int xen_suspend(void *data) |
67 | { | |
ceb18029 | 68 | struct suspend_info *si = data; |
359cdd3f | 69 | int err; |
0e91398f JF |
70 | |
71 | BUG_ON(!irqs_disabled()); | |
72 | ||
2e711c04 | 73 | err = syscore_suspend(); |
770824bd | 74 | if (err) { |
19234c08 | 75 | printk(KERN_ERR "xen_suspend: system core suspend failed: %d\n", |
770824bd | 76 | err); |
770824bd RW |
77 | return err; |
78 | } | |
359cdd3f | 79 | |
55fb4ace IC |
80 | if (si->pre) |
81 | si->pre(); | |
0e91398f JF |
82 | |
83 | /* | |
84 | * This hypercall returns 1 if suspend was cancelled | |
85 | * or the domain was merely checkpointed, and 0 if it | |
86 | * is resuming in a new domain. | |
87 | */ | |
36b401e2 | 88 | si->cancelled = HYPERVISOR_suspend(si->arg); |
0e91398f | 89 | |
55fb4ace IC |
90 | if (si->post) |
91 | si->post(si->cancelled); | |
0e91398f | 92 | |
ceb18029 | 93 | if (!si->cancelled) { |
0e91398f JF |
94 | xen_irq_resume(); |
95 | xen_console_resume(); | |
ad55db9f | 96 | xen_timer_resume(); |
0e91398f JF |
97 | } |
98 | ||
19234c08 | 99 | syscore_resume(); |
1e6fcf84 | 100 | |
0e91398f JF |
101 | return 0; |
102 | } | |
103 | ||
104 | static void do_suspend(void) | |
105 | { | |
106 | int err; | |
ceb18029 | 107 | struct suspend_info si; |
0e91398f JF |
108 | |
109 | shutting_down = SHUTDOWN_SUSPEND; | |
110 | ||
111 | #ifdef CONFIG_PREEMPT | |
112 | /* If the kernel is preemptible, we need to freeze all the processes | |
113 | to prevent them from being in the middle of a pagetable update | |
114 | during suspend. */ | |
115 | err = freeze_processes(); | |
116 | if (err) { | |
117 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
3fc1f1e2 | 118 | goto out; |
0e91398f JF |
119 | } |
120 | #endif | |
121 | ||
b3e96c0c | 122 | err = dpm_suspend_start(PMSG_FREEZE); |
0e91398f | 123 | if (err) { |
d1616302 | 124 | printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); |
65f63384 | 125 | goto out_thaw; |
0e91398f JF |
126 | } |
127 | ||
c5cae661 IC |
128 | printk(KERN_DEBUG "suspending xenstore...\n"); |
129 | xs_suspend(); | |
130 | ||
b3e96c0c | 131 | err = dpm_suspend_noirq(PMSG_FREEZE); |
2ed8d2b3 | 132 | if (err) { |
d1616302 | 133 | printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err); |
65f63384 | 134 | goto out_resume; |
2ed8d2b3 RW |
135 | } |
136 | ||
ceb18029 IC |
137 | si.cancelled = 1; |
138 | ||
55fb4ace | 139 | if (xen_hvm_domain()) { |
36b401e2 | 140 | si.arg = 0UL; |
55fb4ace IC |
141 | si.pre = NULL; |
142 | si.post = &xen_hvm_post_suspend; | |
143 | } else { | |
36b401e2 | 144 | si.arg = virt_to_mfn(xen_start_info); |
55fb4ace IC |
145 | si.pre = &xen_pre_suspend; |
146 | si.post = &xen_post_suspend; | |
147 | } | |
36b401e2 | 148 | |
b056b6a0 | 149 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); |
922cc38a | 150 | |
b3e96c0c | 151 | dpm_resume_noirq(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
922cc38a | 152 | |
0e91398f JF |
153 | if (err) { |
154 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); | |
ceb18029 | 155 | si.cancelled = 1; |
0e91398f JF |
156 | } |
157 | ||
c5cae661 | 158 | out_resume: |
ceb18029 | 159 | if (!si.cancelled) { |
ad55db9f | 160 | xen_arch_resume(); |
de5b31bd | 161 | xs_resume(); |
ad55db9f | 162 | } else |
de5b31bd | 163 | xs_suspend_cancel(); |
0e91398f | 164 | |
b3e96c0c | 165 | dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
0e91398f | 166 | |
359cdd3f JF |
167 | /* Make sure timer events get retriggered on all CPUs */ |
168 | clock_was_set(); | |
65f63384 IC |
169 | |
170 | out_thaw: | |
0e91398f JF |
171 | #ifdef CONFIG_PREEMPT |
172 | thaw_processes(); | |
65f63384 | 173 | out: |
3fc1f1e2 | 174 | #endif |
0e91398f JF |
175 | shutting_down = SHUTDOWN_INVALID; |
176 | } | |
1f112cee | 177 | #endif /* CONFIG_HIBERNATE_CALLBACKS */ |
3e2b8fbe | 178 | |
55271723 IC |
179 | struct shutdown_handler { |
180 | const char *command; | |
181 | void (*cb)(void); | |
182 | }; | |
183 | ||
184 | static void do_poweroff(void) | |
185 | { | |
186 | shutting_down = SHUTDOWN_POWEROFF; | |
187 | orderly_poweroff(false); | |
188 | } | |
189 | ||
190 | static void do_reboot(void) | |
191 | { | |
192 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
193 | ctrl_alt_del(); | |
194 | } | |
195 | ||
3e2b8fbe JF |
196 | static void shutdown_handler(struct xenbus_watch *watch, |
197 | const char **vec, unsigned int len) | |
198 | { | |
199 | char *str; | |
200 | struct xenbus_transaction xbt; | |
201 | int err; | |
55271723 IC |
202 | static struct shutdown_handler handlers[] = { |
203 | { "poweroff", do_poweroff }, | |
204 | { "halt", do_poweroff }, | |
205 | { "reboot", do_reboot }, | |
1f112cee | 206 | #ifdef CONFIG_HIBERNATE_CALLBACKS |
55271723 IC |
207 | { "suspend", do_suspend }, |
208 | #endif | |
209 | {NULL, NULL}, | |
210 | }; | |
211 | static struct shutdown_handler *handler; | |
3e2b8fbe JF |
212 | |
213 | if (shutting_down != SHUTDOWN_INVALID) | |
214 | return; | |
215 | ||
216 | again: | |
217 | err = xenbus_transaction_start(&xbt); | |
218 | if (err) | |
219 | return; | |
220 | ||
221 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
222 | /* Ignore read errors and empty reads. */ | |
223 | if (XENBUS_IS_ERR_READ(str)) { | |
224 | xenbus_transaction_end(xbt, 1); | |
225 | return; | |
226 | } | |
227 | ||
55271723 IC |
228 | for (handler = &handlers[0]; handler->command; handler++) { |
229 | if (strcmp(str, handler->command) == 0) | |
230 | break; | |
231 | } | |
232 | ||
233 | /* Only acknowledge commands which we are prepared to handle. */ | |
234 | if (handler->cb) | |
235 | xenbus_write(xbt, "control", "shutdown", ""); | |
3e2b8fbe JF |
236 | |
237 | err = xenbus_transaction_end(xbt, 0); | |
238 | if (err == -EAGAIN) { | |
239 | kfree(str); | |
240 | goto again; | |
241 | } | |
242 | ||
55271723 IC |
243 | if (handler->cb) { |
244 | handler->cb(); | |
0e91398f | 245 | } else { |
3e2b8fbe JF |
246 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
247 | shutting_down = SHUTDOWN_INVALID; | |
248 | } | |
249 | ||
250 | kfree(str); | |
251 | } | |
252 | ||
f3bc3189 | 253 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
254 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, |
255 | unsigned int len) | |
256 | { | |
257 | char sysrq_key = '\0'; | |
258 | struct xenbus_transaction xbt; | |
259 | int err; | |
260 | ||
261 | again: | |
262 | err = xenbus_transaction_start(&xbt); | |
263 | if (err) | |
264 | return; | |
265 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
266 | printk(KERN_ERR "Unable to read sysrq code in " | |
267 | "control/sysrq\n"); | |
268 | xenbus_transaction_end(xbt, 1); | |
269 | return; | |
270 | } | |
271 | ||
272 | if (sysrq_key != '\0') | |
273 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
274 | ||
275 | err = xenbus_transaction_end(xbt, 0); | |
276 | if (err == -EAGAIN) | |
277 | goto again; | |
278 | ||
279 | if (sysrq_key != '\0') | |
f335397d | 280 | handle_sysrq(sysrq_key); |
3e2b8fbe JF |
281 | } |
282 | ||
3e2b8fbe JF |
283 | static struct xenbus_watch sysrq_watch = { |
284 | .node = "control/sysrq", | |
285 | .callback = sysrq_handler | |
286 | }; | |
f3bc3189 RD |
287 | #endif |
288 | ||
289 | static struct xenbus_watch shutdown_watch = { | |
290 | .node = "control/shutdown", | |
291 | .callback = shutdown_handler | |
292 | }; | |
3e2b8fbe JF |
293 | |
294 | static int setup_shutdown_watcher(void) | |
295 | { | |
296 | int err; | |
297 | ||
298 | err = register_xenbus_watch(&shutdown_watch); | |
299 | if (err) { | |
300 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
301 | return err; | |
302 | } | |
303 | ||
f3bc3189 | 304 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
305 | err = register_xenbus_watch(&sysrq_watch); |
306 | if (err) { | |
307 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
308 | return err; | |
309 | } | |
f3bc3189 | 310 | #endif |
3e2b8fbe JF |
311 | |
312 | return 0; | |
313 | } | |
314 | ||
315 | static int shutdown_event(struct notifier_block *notifier, | |
316 | unsigned long event, | |
317 | void *data) | |
318 | { | |
319 | setup_shutdown_watcher(); | |
320 | return NOTIFY_DONE; | |
321 | } | |
322 | ||
016b6f5f | 323 | int xen_setup_shutdown_event(void) |
3e2b8fbe JF |
324 | { |
325 | static struct notifier_block xenstore_notifier = { | |
326 | .notifier_call = shutdown_event | |
327 | }; | |
702d4eb9 SS |
328 | |
329 | if (!xen_domain()) | |
330 | return -ENODEV; | |
3e2b8fbe JF |
331 | register_xenstore_notifier(&xenstore_notifier); |
332 | ||
333 | return 0; | |
334 | } | |
183d03cc | 335 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 336 | |
702d4eb9 | 337 | subsys_initcall(xen_setup_shutdown_event); |