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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> | |
3e2b8fbe | 11 | |
016b6f5f | 12 | #include <xen/xen.h> |
3e2b8fbe | 13 | #include <xen/xenbus.h> |
0e91398f JF |
14 | #include <xen/grant_table.h> |
15 | #include <xen/events.h> | |
16 | #include <xen/hvc-console.h> | |
17 | #include <xen/xen-ops.h> | |
3e2b8fbe | 18 | |
0e91398f JF |
19 | #include <asm/xen/hypercall.h> |
20 | #include <asm/xen/page.h> | |
016b6f5f | 21 | #include <asm/xen/hypervisor.h> |
0e91398f JF |
22 | |
23 | enum shutdown_state { | |
24 | SHUTDOWN_INVALID = -1, | |
25 | SHUTDOWN_POWEROFF = 0, | |
26 | SHUTDOWN_SUSPEND = 2, | |
27 | /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only | |
28 | report a crash, not be instructed to crash! | |
29 | HALT is the same as POWEROFF, as far as we're concerned. The tools use | |
30 | the distinction when we return the reason code to them. */ | |
31 | SHUTDOWN_HALT = 4, | |
32 | }; | |
3e2b8fbe JF |
33 | |
34 | /* Ignore multiple shutdown requests. */ | |
0e91398f JF |
35 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
36 | ||
ceb18029 IC |
37 | struct suspend_info { |
38 | int cancelled; | |
36b401e2 | 39 | unsigned long arg; /* extra hypercall argument */ |
55fb4ace IC |
40 | void (*pre)(void); |
41 | void (*post)(int cancelled); | |
ceb18029 IC |
42 | }; |
43 | ||
07af3810 | 44 | static void xen_hvm_post_suspend(int cancelled) |
82043bb6 | 45 | { |
07af3810 | 46 | xen_arch_hvm_post_suspend(cancelled); |
82043bb6 IC |
47 | gnttab_resume(); |
48 | } | |
49 | ||
50 | static void xen_pre_suspend(void) | |
51 | { | |
52 | xen_mm_pin_all(); | |
53 | gnttab_suspend(); | |
07af3810 | 54 | xen_arch_pre_suspend(); |
82043bb6 IC |
55 | } |
56 | ||
07af3810 | 57 | static void xen_post_suspend(int cancelled) |
82043bb6 | 58 | { |
07af3810 | 59 | xen_arch_post_suspend(cancelled); |
82043bb6 IC |
60 | gnttab_resume(); |
61 | xen_mm_unpin_all(); | |
62 | } | |
63 | ||
c7827728 | 64 | #ifdef CONFIG_PM_SLEEP |
016b6f5f | 65 | static int xen_hvm_suspend(void *data) |
0e91398f | 66 | { |
ceb18029 | 67 | struct suspend_info *si = data; |
8dd38383 | 68 | int err; |
016b6f5f SS |
69 | |
70 | BUG_ON(!irqs_disabled()); | |
71 | ||
8dd38383 IC |
72 | err = sysdev_suspend(PMSG_SUSPEND); |
73 | if (err) { | |
74 | printk(KERN_ERR "xen_hvm_suspend: sysdev_suspend failed: %d\n", | |
75 | err); | |
76 | return err; | |
77 | } | |
78 | ||
55fb4ace IC |
79 | if (si->pre) |
80 | si->pre(); | |
81 | ||
bd1c0ad2 IC |
82 | /* |
83 | * This hypercall returns 1 if suspend was cancelled | |
84 | * or the domain was merely checkpointed, and 0 if it | |
85 | * is resuming in a new domain. | |
86 | */ | |
36b401e2 | 87 | si->cancelled = HYPERVISOR_suspend(si->arg); |
016b6f5f | 88 | |
55fb4ace IC |
89 | if (si->post) |
90 | si->post(si->cancelled); | |
016b6f5f | 91 | |
ceb18029 | 92 | if (!si->cancelled) { |
016b6f5f | 93 | xen_irq_resume(); |
6411fe69 | 94 | xen_console_resume(); |
016b6f5f SS |
95 | xen_timer_resume(); |
96 | } | |
97 | ||
8dd38383 IC |
98 | sysdev_resume(); |
99 | ||
016b6f5f SS |
100 | return 0; |
101 | } | |
102 | ||
103 | static int xen_suspend(void *data) | |
104 | { | |
ceb18029 | 105 | struct suspend_info *si = data; |
359cdd3f | 106 | int err; |
0e91398f JF |
107 | |
108 | BUG_ON(!irqs_disabled()); | |
109 | ||
770824bd RW |
110 | err = sysdev_suspend(PMSG_SUSPEND); |
111 | if (err) { | |
112 | printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n", | |
113 | err); | |
770824bd RW |
114 | return err; |
115 | } | |
359cdd3f | 116 | |
55fb4ace IC |
117 | if (si->pre) |
118 | si->pre(); | |
0e91398f JF |
119 | |
120 | /* | |
121 | * This hypercall returns 1 if suspend was cancelled | |
122 | * or the domain was merely checkpointed, and 0 if it | |
123 | * is resuming in a new domain. | |
124 | */ | |
36b401e2 | 125 | si->cancelled = HYPERVISOR_suspend(si->arg); |
0e91398f | 126 | |
55fb4ace IC |
127 | if (si->post) |
128 | si->post(si->cancelled); | |
0e91398f | 129 | |
ceb18029 | 130 | if (!si->cancelled) { |
0e91398f JF |
131 | xen_irq_resume(); |
132 | xen_console_resume(); | |
ad55db9f | 133 | xen_timer_resume(); |
0e91398f JF |
134 | } |
135 | ||
1e6fcf84 | 136 | sysdev_resume(); |
1e6fcf84 | 137 | |
0e91398f JF |
138 | return 0; |
139 | } | |
140 | ||
141 | static void do_suspend(void) | |
142 | { | |
143 | int err; | |
ceb18029 | 144 | struct suspend_info si; |
0e91398f JF |
145 | |
146 | shutting_down = SHUTDOWN_SUSPEND; | |
147 | ||
148 | #ifdef CONFIG_PREEMPT | |
149 | /* If the kernel is preemptible, we need to freeze all the processes | |
150 | to prevent them from being in the middle of a pagetable update | |
151 | during suspend. */ | |
152 | err = freeze_processes(); | |
153 | if (err) { | |
154 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
3fc1f1e2 | 155 | goto out; |
0e91398f JF |
156 | } |
157 | #endif | |
158 | ||
d1616302 | 159 | err = dpm_suspend_start(PMSG_SUSPEND); |
0e91398f | 160 | if (err) { |
d1616302 | 161 | printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); |
65f63384 | 162 | goto out_thaw; |
0e91398f JF |
163 | } |
164 | ||
c5cae661 IC |
165 | printk(KERN_DEBUG "suspending xenstore...\n"); |
166 | xs_suspend(); | |
167 | ||
d1616302 | 168 | err = dpm_suspend_noirq(PMSG_SUSPEND); |
2ed8d2b3 | 169 | if (err) { |
d1616302 | 170 | printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err); |
65f63384 | 171 | goto out_resume; |
2ed8d2b3 RW |
172 | } |
173 | ||
ceb18029 IC |
174 | si.cancelled = 1; |
175 | ||
55fb4ace | 176 | if (xen_hvm_domain()) { |
36b401e2 | 177 | si.arg = 0UL; |
55fb4ace IC |
178 | si.pre = NULL; |
179 | si.post = &xen_hvm_post_suspend; | |
180 | } else { | |
36b401e2 | 181 | si.arg = virt_to_mfn(xen_start_info); |
55fb4ace IC |
182 | si.pre = &xen_pre_suspend; |
183 | si.post = &xen_post_suspend; | |
184 | } | |
36b401e2 | 185 | |
016b6f5f | 186 | if (xen_hvm_domain()) |
ceb18029 | 187 | err = stop_machine(xen_hvm_suspend, &si, cpumask_of(0)); |
016b6f5f | 188 | else |
ceb18029 | 189 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); |
922cc38a JF |
190 | |
191 | dpm_resume_noirq(PMSG_RESUME); | |
192 | ||
0e91398f JF |
193 | if (err) { |
194 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); | |
ceb18029 | 195 | si.cancelled = 1; |
0e91398f JF |
196 | } |
197 | ||
c5cae661 | 198 | out_resume: |
ceb18029 | 199 | if (!si.cancelled) { |
ad55db9f | 200 | xen_arch_resume(); |
de5b31bd | 201 | xs_resume(); |
ad55db9f | 202 | } else |
de5b31bd | 203 | xs_suspend_cancel(); |
0e91398f | 204 | |
d1616302 | 205 | dpm_resume_end(PMSG_RESUME); |
0e91398f | 206 | |
359cdd3f JF |
207 | /* Make sure timer events get retriggered on all CPUs */ |
208 | clock_was_set(); | |
65f63384 IC |
209 | |
210 | out_thaw: | |
0e91398f JF |
211 | #ifdef CONFIG_PREEMPT |
212 | thaw_processes(); | |
65f63384 | 213 | out: |
3fc1f1e2 | 214 | #endif |
0e91398f JF |
215 | shutting_down = SHUTDOWN_INVALID; |
216 | } | |
c7827728 | 217 | #endif /* CONFIG_PM_SLEEP */ |
3e2b8fbe | 218 | |
55271723 IC |
219 | struct shutdown_handler { |
220 | const char *command; | |
221 | void (*cb)(void); | |
222 | }; | |
223 | ||
224 | static void do_poweroff(void) | |
225 | { | |
226 | shutting_down = SHUTDOWN_POWEROFF; | |
227 | orderly_poweroff(false); | |
228 | } | |
229 | ||
230 | static void do_reboot(void) | |
231 | { | |
232 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
233 | ctrl_alt_del(); | |
234 | } | |
235 | ||
3e2b8fbe JF |
236 | static void shutdown_handler(struct xenbus_watch *watch, |
237 | const char **vec, unsigned int len) | |
238 | { | |
239 | char *str; | |
240 | struct xenbus_transaction xbt; | |
241 | int err; | |
55271723 IC |
242 | static struct shutdown_handler handlers[] = { |
243 | { "poweroff", do_poweroff }, | |
244 | { "halt", do_poweroff }, | |
245 | { "reboot", do_reboot }, | |
246 | #ifdef CONFIG_PM_SLEEP | |
247 | { "suspend", do_suspend }, | |
248 | #endif | |
249 | {NULL, NULL}, | |
250 | }; | |
251 | static struct shutdown_handler *handler; | |
3e2b8fbe JF |
252 | |
253 | if (shutting_down != SHUTDOWN_INVALID) | |
254 | return; | |
255 | ||
256 | again: | |
257 | err = xenbus_transaction_start(&xbt); | |
258 | if (err) | |
259 | return; | |
260 | ||
261 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
262 | /* Ignore read errors and empty reads. */ | |
263 | if (XENBUS_IS_ERR_READ(str)) { | |
264 | xenbus_transaction_end(xbt, 1); | |
265 | return; | |
266 | } | |
267 | ||
55271723 IC |
268 | for (handler = &handlers[0]; handler->command; handler++) { |
269 | if (strcmp(str, handler->command) == 0) | |
270 | break; | |
271 | } | |
272 | ||
273 | /* Only acknowledge commands which we are prepared to handle. */ | |
274 | if (handler->cb) | |
275 | xenbus_write(xbt, "control", "shutdown", ""); | |
3e2b8fbe JF |
276 | |
277 | err = xenbus_transaction_end(xbt, 0); | |
278 | if (err == -EAGAIN) { | |
279 | kfree(str); | |
280 | goto again; | |
281 | } | |
282 | ||
55271723 IC |
283 | if (handler->cb) { |
284 | handler->cb(); | |
0e91398f | 285 | } else { |
3e2b8fbe JF |
286 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
287 | shutting_down = SHUTDOWN_INVALID; | |
288 | } | |
289 | ||
290 | kfree(str); | |
291 | } | |
292 | ||
f3bc3189 | 293 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
294 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, |
295 | unsigned int len) | |
296 | { | |
297 | char sysrq_key = '\0'; | |
298 | struct xenbus_transaction xbt; | |
299 | int err; | |
300 | ||
301 | again: | |
302 | err = xenbus_transaction_start(&xbt); | |
303 | if (err) | |
304 | return; | |
305 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
306 | printk(KERN_ERR "Unable to read sysrq code in " | |
307 | "control/sysrq\n"); | |
308 | xenbus_transaction_end(xbt, 1); | |
309 | return; | |
310 | } | |
311 | ||
312 | if (sysrq_key != '\0') | |
313 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
314 | ||
315 | err = xenbus_transaction_end(xbt, 0); | |
316 | if (err == -EAGAIN) | |
317 | goto again; | |
318 | ||
319 | if (sysrq_key != '\0') | |
f335397d | 320 | handle_sysrq(sysrq_key); |
3e2b8fbe JF |
321 | } |
322 | ||
3e2b8fbe JF |
323 | static struct xenbus_watch sysrq_watch = { |
324 | .node = "control/sysrq", | |
325 | .callback = sysrq_handler | |
326 | }; | |
f3bc3189 RD |
327 | #endif |
328 | ||
329 | static struct xenbus_watch shutdown_watch = { | |
330 | .node = "control/shutdown", | |
331 | .callback = shutdown_handler | |
332 | }; | |
3e2b8fbe JF |
333 | |
334 | static int setup_shutdown_watcher(void) | |
335 | { | |
336 | int err; | |
337 | ||
338 | err = register_xenbus_watch(&shutdown_watch); | |
339 | if (err) { | |
340 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
341 | return err; | |
342 | } | |
343 | ||
f3bc3189 | 344 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
345 | err = register_xenbus_watch(&sysrq_watch); |
346 | if (err) { | |
347 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
348 | return err; | |
349 | } | |
f3bc3189 | 350 | #endif |
3e2b8fbe JF |
351 | |
352 | return 0; | |
353 | } | |
354 | ||
355 | static int shutdown_event(struct notifier_block *notifier, | |
356 | unsigned long event, | |
357 | void *data) | |
358 | { | |
359 | setup_shutdown_watcher(); | |
360 | return NOTIFY_DONE; | |
361 | } | |
362 | ||
016b6f5f | 363 | int xen_setup_shutdown_event(void) |
3e2b8fbe JF |
364 | { |
365 | static struct notifier_block xenstore_notifier = { | |
366 | .notifier_call = shutdown_event | |
367 | }; | |
702d4eb9 SS |
368 | |
369 | if (!xen_domain()) | |
370 | return -ENODEV; | |
3e2b8fbe JF |
371 | register_xenstore_notifier(&xenstore_notifier); |
372 | ||
373 | return 0; | |
374 | } | |
183d03cc | 375 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 376 | |
702d4eb9 | 377 | subsys_initcall(xen_setup_shutdown_event); |