Commit | Line | Data |
---|---|---|
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> |
63c9744b | 12 | #include <linux/export.h> |
3e2b8fbe | 13 | |
016b6f5f | 14 | #include <xen/xen.h> |
3e2b8fbe | 15 | #include <xen/xenbus.h> |
0e91398f JF |
16 | #include <xen/grant_table.h> |
17 | #include <xen/events.h> | |
18 | #include <xen/hvc-console.h> | |
19 | #include <xen/xen-ops.h> | |
3e2b8fbe | 20 | |
0e91398f JF |
21 | #include <asm/xen/hypercall.h> |
22 | #include <asm/xen/page.h> | |
016b6f5f | 23 | #include <asm/xen/hypervisor.h> |
0e91398f JF |
24 | |
25 | enum shutdown_state { | |
26 | SHUTDOWN_INVALID = -1, | |
27 | SHUTDOWN_POWEROFF = 0, | |
28 | SHUTDOWN_SUSPEND = 2, | |
29 | /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only | |
30 | report a crash, not be instructed to crash! | |
31 | HALT is the same as POWEROFF, as far as we're concerned. The tools use | |
32 | the distinction when we return the reason code to them. */ | |
33 | SHUTDOWN_HALT = 4, | |
34 | }; | |
3e2b8fbe JF |
35 | |
36 | /* Ignore multiple shutdown requests. */ | |
0e91398f JF |
37 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
38 | ||
ceb18029 IC |
39 | struct suspend_info { |
40 | int cancelled; | |
36b401e2 | 41 | unsigned long arg; /* extra hypercall argument */ |
55fb4ace IC |
42 | void (*pre)(void); |
43 | void (*post)(int cancelled); | |
ceb18029 IC |
44 | }; |
45 | ||
07af3810 | 46 | static void xen_hvm_post_suspend(int cancelled) |
82043bb6 | 47 | { |
07af3810 | 48 | xen_arch_hvm_post_suspend(cancelled); |
82043bb6 IC |
49 | gnttab_resume(); |
50 | } | |
51 | ||
52 | static void xen_pre_suspend(void) | |
53 | { | |
54 | xen_mm_pin_all(); | |
55 | gnttab_suspend(); | |
07af3810 | 56 | xen_arch_pre_suspend(); |
82043bb6 IC |
57 | } |
58 | ||
07af3810 | 59 | static void xen_post_suspend(int cancelled) |
82043bb6 | 60 | { |
07af3810 | 61 | xen_arch_post_suspend(cancelled); |
82043bb6 IC |
62 | gnttab_resume(); |
63 | xen_mm_unpin_all(); | |
64 | } | |
65 | ||
1f112cee | 66 | #ifdef CONFIG_HIBERNATE_CALLBACKS |
016b6f5f SS |
67 | static int xen_suspend(void *data) |
68 | { | |
ceb18029 | 69 | struct suspend_info *si = data; |
359cdd3f | 70 | int err; |
0e91398f JF |
71 | |
72 | BUG_ON(!irqs_disabled()); | |
73 | ||
2e711c04 | 74 | err = syscore_suspend(); |
770824bd | 75 | if (err) { |
19234c08 | 76 | printk(KERN_ERR "xen_suspend: system core suspend failed: %d\n", |
770824bd | 77 | err); |
770824bd RW |
78 | return err; |
79 | } | |
359cdd3f | 80 | |
55fb4ace IC |
81 | if (si->pre) |
82 | si->pre(); | |
0e91398f JF |
83 | |
84 | /* | |
85 | * This hypercall returns 1 if suspend was cancelled | |
86 | * or the domain was merely checkpointed, and 0 if it | |
87 | * is resuming in a new domain. | |
88 | */ | |
36b401e2 | 89 | si->cancelled = HYPERVISOR_suspend(si->arg); |
0e91398f | 90 | |
55fb4ace IC |
91 | if (si->post) |
92 | si->post(si->cancelled); | |
0e91398f | 93 | |
ceb18029 | 94 | if (!si->cancelled) { |
0e91398f JF |
95 | xen_irq_resume(); |
96 | xen_console_resume(); | |
ad55db9f | 97 | xen_timer_resume(); |
0e91398f JF |
98 | } |
99 | ||
19234c08 | 100 | syscore_resume(); |
1e6fcf84 | 101 | |
0e91398f JF |
102 | return 0; |
103 | } | |
104 | ||
105 | static void do_suspend(void) | |
106 | { | |
107 | int err; | |
ceb18029 | 108 | struct suspend_info si; |
0e91398f JF |
109 | |
110 | shutting_down = SHUTDOWN_SUSPEND; | |
111 | ||
112 | #ifdef CONFIG_PREEMPT | |
113 | /* If the kernel is preemptible, we need to freeze all the processes | |
114 | to prevent them from being in the middle of a pagetable update | |
115 | during suspend. */ | |
116 | err = freeze_processes(); | |
117 | if (err) { | |
118 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
3fc1f1e2 | 119 | goto out; |
0e91398f JF |
120 | } |
121 | #endif | |
122 | ||
b3e96c0c | 123 | err = dpm_suspend_start(PMSG_FREEZE); |
0e91398f | 124 | if (err) { |
d1616302 | 125 | printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); |
65f63384 | 126 | goto out_thaw; |
0e91398f JF |
127 | } |
128 | ||
c5cae661 IC |
129 | printk(KERN_DEBUG "suspending xenstore...\n"); |
130 | xs_suspend(); | |
131 | ||
cf579dfb | 132 | err = dpm_suspend_end(PMSG_FREEZE); |
2ed8d2b3 | 133 | if (err) { |
cf579dfb | 134 | printk(KERN_ERR "dpm_suspend_end failed: %d\n", err); |
65f63384 | 135 | goto out_resume; |
2ed8d2b3 RW |
136 | } |
137 | ||
ceb18029 IC |
138 | si.cancelled = 1; |
139 | ||
55fb4ace | 140 | if (xen_hvm_domain()) { |
36b401e2 | 141 | si.arg = 0UL; |
55fb4ace IC |
142 | si.pre = NULL; |
143 | si.post = &xen_hvm_post_suspend; | |
144 | } else { | |
36b401e2 | 145 | si.arg = virt_to_mfn(xen_start_info); |
55fb4ace IC |
146 | si.pre = &xen_pre_suspend; |
147 | si.post = &xen_post_suspend; | |
148 | } | |
36b401e2 | 149 | |
b056b6a0 | 150 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); |
922cc38a | 151 | |
cf579dfb | 152 | dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
922cc38a | 153 | |
0e91398f JF |
154 | if (err) { |
155 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); | |
ceb18029 | 156 | si.cancelled = 1; |
0e91398f JF |
157 | } |
158 | ||
c5cae661 | 159 | out_resume: |
ceb18029 | 160 | if (!si.cancelled) { |
ad55db9f | 161 | xen_arch_resume(); |
de5b31bd | 162 | xs_resume(); |
ad55db9f | 163 | } else |
de5b31bd | 164 | xs_suspend_cancel(); |
0e91398f | 165 | |
b3e96c0c | 166 | dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
0e91398f | 167 | |
359cdd3f JF |
168 | /* Make sure timer events get retriggered on all CPUs */ |
169 | clock_was_set(); | |
65f63384 IC |
170 | |
171 | out_thaw: | |
0e91398f JF |
172 | #ifdef CONFIG_PREEMPT |
173 | thaw_processes(); | |
65f63384 | 174 | out: |
3fc1f1e2 | 175 | #endif |
0e91398f JF |
176 | shutting_down = SHUTDOWN_INVALID; |
177 | } | |
1f112cee | 178 | #endif /* CONFIG_HIBERNATE_CALLBACKS */ |
3e2b8fbe | 179 | |
55271723 IC |
180 | struct shutdown_handler { |
181 | const char *command; | |
182 | void (*cb)(void); | |
183 | }; | |
184 | ||
185 | static void do_poweroff(void) | |
186 | { | |
187 | shutting_down = SHUTDOWN_POWEROFF; | |
188 | orderly_poweroff(false); | |
189 | } | |
190 | ||
191 | static void do_reboot(void) | |
192 | { | |
193 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
194 | ctrl_alt_del(); | |
195 | } | |
196 | ||
3e2b8fbe JF |
197 | static void shutdown_handler(struct xenbus_watch *watch, |
198 | const char **vec, unsigned int len) | |
199 | { | |
200 | char *str; | |
201 | struct xenbus_transaction xbt; | |
202 | int err; | |
55271723 IC |
203 | static struct shutdown_handler handlers[] = { |
204 | { "poweroff", do_poweroff }, | |
205 | { "halt", do_poweroff }, | |
206 | { "reboot", do_reboot }, | |
1f112cee | 207 | #ifdef CONFIG_HIBERNATE_CALLBACKS |
55271723 IC |
208 | { "suspend", do_suspend }, |
209 | #endif | |
210 | {NULL, NULL}, | |
211 | }; | |
212 | static struct shutdown_handler *handler; | |
3e2b8fbe JF |
213 | |
214 | if (shutting_down != SHUTDOWN_INVALID) | |
215 | return; | |
216 | ||
217 | again: | |
218 | err = xenbus_transaction_start(&xbt); | |
219 | if (err) | |
220 | return; | |
221 | ||
222 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
223 | /* Ignore read errors and empty reads. */ | |
224 | if (XENBUS_IS_ERR_READ(str)) { | |
225 | xenbus_transaction_end(xbt, 1); | |
226 | return; | |
227 | } | |
228 | ||
55271723 IC |
229 | for (handler = &handlers[0]; handler->command; handler++) { |
230 | if (strcmp(str, handler->command) == 0) | |
231 | break; | |
232 | } | |
233 | ||
234 | /* Only acknowledge commands which we are prepared to handle. */ | |
235 | if (handler->cb) | |
236 | xenbus_write(xbt, "control", "shutdown", ""); | |
3e2b8fbe JF |
237 | |
238 | err = xenbus_transaction_end(xbt, 0); | |
239 | if (err == -EAGAIN) { | |
240 | kfree(str); | |
241 | goto again; | |
242 | } | |
243 | ||
55271723 IC |
244 | if (handler->cb) { |
245 | handler->cb(); | |
0e91398f | 246 | } else { |
3e2b8fbe JF |
247 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
248 | shutting_down = SHUTDOWN_INVALID; | |
249 | } | |
250 | ||
251 | kfree(str); | |
252 | } | |
253 | ||
f3bc3189 | 254 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
255 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, |
256 | unsigned int len) | |
257 | { | |
258 | char sysrq_key = '\0'; | |
259 | struct xenbus_transaction xbt; | |
260 | int err; | |
261 | ||
262 | again: | |
263 | err = xenbus_transaction_start(&xbt); | |
264 | if (err) | |
265 | return; | |
266 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
267 | printk(KERN_ERR "Unable to read sysrq code in " | |
268 | "control/sysrq\n"); | |
269 | xenbus_transaction_end(xbt, 1); | |
270 | return; | |
271 | } | |
272 | ||
273 | if (sysrq_key != '\0') | |
274 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
275 | ||
276 | err = xenbus_transaction_end(xbt, 0); | |
277 | if (err == -EAGAIN) | |
278 | goto again; | |
279 | ||
280 | if (sysrq_key != '\0') | |
f335397d | 281 | handle_sysrq(sysrq_key); |
3e2b8fbe JF |
282 | } |
283 | ||
3e2b8fbe JF |
284 | static struct xenbus_watch sysrq_watch = { |
285 | .node = "control/sysrq", | |
286 | .callback = sysrq_handler | |
287 | }; | |
f3bc3189 RD |
288 | #endif |
289 | ||
290 | static struct xenbus_watch shutdown_watch = { | |
291 | .node = "control/shutdown", | |
292 | .callback = shutdown_handler | |
293 | }; | |
3e2b8fbe JF |
294 | |
295 | static int setup_shutdown_watcher(void) | |
296 | { | |
297 | int err; | |
298 | ||
299 | err = register_xenbus_watch(&shutdown_watch); | |
300 | if (err) { | |
301 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
302 | return err; | |
303 | } | |
304 | ||
f3bc3189 | 305 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
306 | err = register_xenbus_watch(&sysrq_watch); |
307 | if (err) { | |
308 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
309 | return err; | |
310 | } | |
f3bc3189 | 311 | #endif |
3e2b8fbe JF |
312 | |
313 | return 0; | |
314 | } | |
315 | ||
316 | static int shutdown_event(struct notifier_block *notifier, | |
317 | unsigned long event, | |
318 | void *data) | |
319 | { | |
320 | setup_shutdown_watcher(); | |
321 | return NOTIFY_DONE; | |
322 | } | |
323 | ||
016b6f5f | 324 | int xen_setup_shutdown_event(void) |
3e2b8fbe JF |
325 | { |
326 | static struct notifier_block xenstore_notifier = { | |
327 | .notifier_call = shutdown_event | |
328 | }; | |
702d4eb9 SS |
329 | |
330 | if (!xen_domain()) | |
331 | return -ENODEV; | |
3e2b8fbe JF |
332 | register_xenstore_notifier(&xenstore_notifier); |
333 | ||
334 | return 0; | |
335 | } | |
183d03cc | 336 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 337 | |
702d4eb9 | 338 | subsys_initcall(xen_setup_shutdown_event); |