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Commit | Line | Data |
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3e2b8fbe JF |
1 | /* |
2 | * Handle extern requests for shutdown, reboot and sysrq | |
3 | */ | |
283c0972 JP |
4 | |
5 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt | |
6 | ||
3e2b8fbe JF |
7 | #include <linux/kernel.h> |
8 | #include <linux/err.h> | |
5a0e3ad6 | 9 | #include <linux/slab.h> |
3e2b8fbe JF |
10 | #include <linux/reboot.h> |
11 | #include <linux/sysrq.h> | |
0e91398f JF |
12 | #include <linux/stop_machine.h> |
13 | #include <linux/freezer.h> | |
19234c08 | 14 | #include <linux/syscore_ops.h> |
63c9744b | 15 | #include <linux/export.h> |
3e2b8fbe | 16 | |
016b6f5f | 17 | #include <xen/xen.h> |
3e2b8fbe | 18 | #include <xen/xenbus.h> |
0e91398f JF |
19 | #include <xen/grant_table.h> |
20 | #include <xen/events.h> | |
21 | #include <xen/hvc-console.h> | |
22 | #include <xen/xen-ops.h> | |
3e2b8fbe | 23 | |
0e91398f JF |
24 | #include <asm/xen/hypercall.h> |
25 | #include <asm/xen/page.h> | |
016b6f5f | 26 | #include <asm/xen/hypervisor.h> |
0e91398f JF |
27 | |
28 | enum shutdown_state { | |
29 | SHUTDOWN_INVALID = -1, | |
30 | SHUTDOWN_POWEROFF = 0, | |
31 | SHUTDOWN_SUSPEND = 2, | |
32 | /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only | |
33 | report a crash, not be instructed to crash! | |
34 | HALT is the same as POWEROFF, as far as we're concerned. The tools use | |
35 | the distinction when we return the reason code to them. */ | |
36 | SHUTDOWN_HALT = 4, | |
37 | }; | |
3e2b8fbe JF |
38 | |
39 | /* Ignore multiple shutdown requests. */ | |
0e91398f JF |
40 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
41 | ||
ceb18029 IC |
42 | struct suspend_info { |
43 | int cancelled; | |
44 | }; | |
45 | ||
cd979883 SG |
46 | static RAW_NOTIFIER_HEAD(xen_resume_notifier); |
47 | ||
48 | void xen_resume_notifier_register(struct notifier_block *nb) | |
49 | { | |
50 | raw_notifier_chain_register(&xen_resume_notifier, nb); | |
51 | } | |
52 | EXPORT_SYMBOL_GPL(xen_resume_notifier_register); | |
53 | ||
54 | void xen_resume_notifier_unregister(struct notifier_block *nb) | |
55 | { | |
56 | raw_notifier_chain_unregister(&xen_resume_notifier, nb); | |
57 | } | |
58 | EXPORT_SYMBOL_GPL(xen_resume_notifier_unregister); | |
59 | ||
65e053a7 | 60 | #ifdef CONFIG_HIBERNATE_CALLBACKS |
016b6f5f SS |
61 | static int xen_suspend(void *data) |
62 | { | |
ceb18029 | 63 | struct suspend_info *si = data; |
359cdd3f | 64 | int err; |
0e91398f JF |
65 | |
66 | BUG_ON(!irqs_disabled()); | |
67 | ||
2e711c04 | 68 | err = syscore_suspend(); |
770824bd | 69 | if (err) { |
283c0972 | 70 | pr_err("%s: system core suspend failed: %d\n", __func__, err); |
770824bd RW |
71 | return err; |
72 | } | |
359cdd3f | 73 | |
aa8532c3 DV |
74 | gnttab_suspend(); |
75 | xen_arch_pre_suspend(); | |
0e91398f JF |
76 | |
77 | /* | |
78 | * This hypercall returns 1 if suspend was cancelled | |
79 | * or the domain was merely checkpointed, and 0 if it | |
80 | * is resuming in a new domain. | |
81 | */ | |
aa8532c3 DV |
82 | si->cancelled = HYPERVISOR_suspend(xen_pv_domain() |
83 | ? virt_to_mfn(xen_start_info) | |
84 | : 0); | |
0e91398f | 85 | |
aa8532c3 DV |
86 | xen_arch_post_suspend(si->cancelled); |
87 | gnttab_resume(); | |
0e91398f | 88 | |
ceb18029 | 89 | if (!si->cancelled) { |
0e91398f | 90 | xen_irq_resume(); |
ad55db9f | 91 | xen_timer_resume(); |
0e91398f JF |
92 | } |
93 | ||
19234c08 | 94 | syscore_resume(); |
1e6fcf84 | 95 | |
0e91398f JF |
96 | return 0; |
97 | } | |
98 | ||
99 | static void do_suspend(void) | |
100 | { | |
101 | int err; | |
ceb18029 | 102 | struct suspend_info si; |
0e91398f JF |
103 | |
104 | shutting_down = SHUTDOWN_SUSPEND; | |
105 | ||
0e91398f JF |
106 | err = freeze_processes(); |
107 | if (err) { | |
283c0972 | 108 | pr_err("%s: freeze failed %d\n", __func__, err); |
3fc1f1e2 | 109 | goto out; |
0e91398f | 110 | } |
0e91398f | 111 | |
b3e96c0c | 112 | err = dpm_suspend_start(PMSG_FREEZE); |
0e91398f | 113 | if (err) { |
283c0972 | 114 | pr_err("%s: dpm_suspend_start %d\n", __func__, err); |
65f63384 | 115 | goto out_thaw; |
0e91398f JF |
116 | } |
117 | ||
c5cae661 IC |
118 | printk(KERN_DEBUG "suspending xenstore...\n"); |
119 | xs_suspend(); | |
120 | ||
cf579dfb | 121 | err = dpm_suspend_end(PMSG_FREEZE); |
2ed8d2b3 | 122 | if (err) { |
283c0972 | 123 | pr_err("dpm_suspend_end failed: %d\n", err); |
186bab1c | 124 | si.cancelled = 0; |
65f63384 | 125 | goto out_resume; |
2ed8d2b3 RW |
126 | } |
127 | ||
ceb18029 IC |
128 | si.cancelled = 1; |
129 | ||
b056b6a0 | 130 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); |
922cc38a | 131 | |
1b647823 DV |
132 | /* Resume console as early as possible. */ |
133 | if (!si.cancelled) | |
134 | xen_console_resume(); | |
135 | ||
cd979883 SG |
136 | raw_notifier_call_chain(&xen_resume_notifier, 0, NULL); |
137 | ||
cf579dfb | 138 | dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
922cc38a | 139 | |
0e91398f | 140 | if (err) { |
283c0972 | 141 | pr_err("failed to start xen_suspend: %d\n", err); |
ceb18029 | 142 | si.cancelled = 1; |
0e91398f JF |
143 | } |
144 | ||
c5cae661 | 145 | out_resume: |
ceb18029 | 146 | if (!si.cancelled) { |
ad55db9f | 147 | xen_arch_resume(); |
de5b31bd | 148 | xs_resume(); |
ad55db9f | 149 | } else |
de5b31bd | 150 | xs_suspend_cancel(); |
0e91398f | 151 | |
b3e96c0c | 152 | dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
0e91398f | 153 | |
65f63384 | 154 | out_thaw: |
0e91398f | 155 | thaw_processes(); |
65f63384 | 156 | out: |
0e91398f JF |
157 | shutting_down = SHUTDOWN_INVALID; |
158 | } | |
1f112cee | 159 | #endif /* CONFIG_HIBERNATE_CALLBACKS */ |
3e2b8fbe | 160 | |
55271723 IC |
161 | struct shutdown_handler { |
162 | const char *command; | |
163 | void (*cb)(void); | |
164 | }; | |
165 | ||
eb47f712 KRW |
166 | static int poweroff_nb(struct notifier_block *cb, unsigned long code, void *unused) |
167 | { | |
168 | switch (code) { | |
169 | case SYS_DOWN: | |
170 | case SYS_HALT: | |
171 | case SYS_POWER_OFF: | |
172 | shutting_down = SHUTDOWN_POWEROFF; | |
173 | default: | |
174 | break; | |
175 | } | |
176 | return NOTIFY_DONE; | |
177 | } | |
55271723 IC |
178 | static void do_poweroff(void) |
179 | { | |
eb47f712 KRW |
180 | switch (system_state) { |
181 | case SYSTEM_BOOTING: | |
182 | orderly_poweroff(true); | |
183 | break; | |
184 | case SYSTEM_RUNNING: | |
185 | orderly_poweroff(false); | |
186 | break; | |
187 | default: | |
188 | /* Don't do it when we are halting/rebooting. */ | |
189 | pr_info("Ignoring Xen toolstack shutdown.\n"); | |
190 | break; | |
191 | } | |
55271723 IC |
192 | } |
193 | ||
194 | static void do_reboot(void) | |
195 | { | |
196 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
197 | ctrl_alt_del(); | |
198 | } | |
199 | ||
3e2b8fbe JF |
200 | static void shutdown_handler(struct xenbus_watch *watch, |
201 | const char **vec, unsigned int len) | |
202 | { | |
203 | char *str; | |
204 | struct xenbus_transaction xbt; | |
205 | int err; | |
55271723 IC |
206 | static struct shutdown_handler handlers[] = { |
207 | { "poweroff", do_poweroff }, | |
208 | { "halt", do_poweroff }, | |
209 | { "reboot", do_reboot }, | |
1f112cee | 210 | #ifdef CONFIG_HIBERNATE_CALLBACKS |
55271723 IC |
211 | { "suspend", do_suspend }, |
212 | #endif | |
213 | {NULL, NULL}, | |
214 | }; | |
215 | static struct shutdown_handler *handler; | |
3e2b8fbe JF |
216 | |
217 | if (shutting_down != SHUTDOWN_INVALID) | |
218 | return; | |
219 | ||
220 | again: | |
221 | err = xenbus_transaction_start(&xbt); | |
222 | if (err) | |
223 | return; | |
224 | ||
225 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
226 | /* Ignore read errors and empty reads. */ | |
227 | if (XENBUS_IS_ERR_READ(str)) { | |
228 | xenbus_transaction_end(xbt, 1); | |
229 | return; | |
230 | } | |
231 | ||
55271723 IC |
232 | for (handler = &handlers[0]; handler->command; handler++) { |
233 | if (strcmp(str, handler->command) == 0) | |
234 | break; | |
235 | } | |
236 | ||
237 | /* Only acknowledge commands which we are prepared to handle. */ | |
238 | if (handler->cb) | |
239 | xenbus_write(xbt, "control", "shutdown", ""); | |
3e2b8fbe JF |
240 | |
241 | err = xenbus_transaction_end(xbt, 0); | |
242 | if (err == -EAGAIN) { | |
243 | kfree(str); | |
244 | goto again; | |
245 | } | |
246 | ||
55271723 IC |
247 | if (handler->cb) { |
248 | handler->cb(); | |
0e91398f | 249 | } else { |
283c0972 | 250 | pr_info("Ignoring shutdown request: %s\n", str); |
3e2b8fbe JF |
251 | shutting_down = SHUTDOWN_INVALID; |
252 | } | |
253 | ||
254 | kfree(str); | |
255 | } | |
256 | ||
f3bc3189 | 257 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
258 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, |
259 | unsigned int len) | |
260 | { | |
261 | char sysrq_key = '\0'; | |
262 | struct xenbus_transaction xbt; | |
263 | int err; | |
264 | ||
265 | again: | |
266 | err = xenbus_transaction_start(&xbt); | |
267 | if (err) | |
268 | return; | |
269 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
283c0972 | 270 | pr_err("Unable to read sysrq code in control/sysrq\n"); |
3e2b8fbe JF |
271 | xenbus_transaction_end(xbt, 1); |
272 | return; | |
273 | } | |
274 | ||
275 | if (sysrq_key != '\0') | |
276 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
277 | ||
278 | err = xenbus_transaction_end(xbt, 0); | |
279 | if (err == -EAGAIN) | |
280 | goto again; | |
281 | ||
282 | if (sysrq_key != '\0') | |
f335397d | 283 | handle_sysrq(sysrq_key); |
3e2b8fbe JF |
284 | } |
285 | ||
3e2b8fbe JF |
286 | static struct xenbus_watch sysrq_watch = { |
287 | .node = "control/sysrq", | |
288 | .callback = sysrq_handler | |
289 | }; | |
f3bc3189 RD |
290 | #endif |
291 | ||
292 | static struct xenbus_watch shutdown_watch = { | |
293 | .node = "control/shutdown", | |
294 | .callback = shutdown_handler | |
295 | }; | |
3e2b8fbe | 296 | |
eb47f712 KRW |
297 | static struct notifier_block xen_reboot_nb = { |
298 | .notifier_call = poweroff_nb, | |
299 | }; | |
300 | ||
3e2b8fbe JF |
301 | static int setup_shutdown_watcher(void) |
302 | { | |
303 | int err; | |
304 | ||
305 | err = register_xenbus_watch(&shutdown_watch); | |
306 | if (err) { | |
283c0972 | 307 | pr_err("Failed to set shutdown watcher\n"); |
3e2b8fbe JF |
308 | return err; |
309 | } | |
310 | ||
eb47f712 | 311 | |
f3bc3189 | 312 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
313 | err = register_xenbus_watch(&sysrq_watch); |
314 | if (err) { | |
283c0972 | 315 | pr_err("Failed to set sysrq watcher\n"); |
3e2b8fbe JF |
316 | return err; |
317 | } | |
f3bc3189 | 318 | #endif |
3e2b8fbe JF |
319 | |
320 | return 0; | |
321 | } | |
322 | ||
323 | static int shutdown_event(struct notifier_block *notifier, | |
324 | unsigned long event, | |
325 | void *data) | |
326 | { | |
327 | setup_shutdown_watcher(); | |
328 | return NOTIFY_DONE; | |
329 | } | |
330 | ||
016b6f5f | 331 | int xen_setup_shutdown_event(void) |
3e2b8fbe JF |
332 | { |
333 | static struct notifier_block xenstore_notifier = { | |
334 | .notifier_call = shutdown_event | |
335 | }; | |
702d4eb9 SS |
336 | |
337 | if (!xen_domain()) | |
338 | return -ENODEV; | |
3e2b8fbe | 339 | register_xenstore_notifier(&xenstore_notifier); |
eb47f712 | 340 | register_reboot_notifier(&xen_reboot_nb); |
3e2b8fbe JF |
341 | |
342 | return 0; | |
343 | } | |
183d03cc | 344 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 345 | |
702d4eb9 | 346 | subsys_initcall(xen_setup_shutdown_event); |