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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) { | |
72978b2f | 108 | pr_err("%s: freeze processes failed %d\n", __func__, err); |
3fc1f1e2 | 109 | goto out; |
0e91398f | 110 | } |
0e91398f | 111 | |
72978b2f RL |
112 | err = freeze_kernel_threads(); |
113 | if (err) { | |
114 | pr_err("%s: freeze kernel threads failed %d\n", __func__, err); | |
115 | goto out_thaw; | |
116 | } | |
117 | ||
b3e96c0c | 118 | err = dpm_suspend_start(PMSG_FREEZE); |
0e91398f | 119 | if (err) { |
283c0972 | 120 | pr_err("%s: dpm_suspend_start %d\n", __func__, err); |
65f63384 | 121 | goto out_thaw; |
0e91398f JF |
122 | } |
123 | ||
c5cae661 IC |
124 | printk(KERN_DEBUG "suspending xenstore...\n"); |
125 | xs_suspend(); | |
126 | ||
cf579dfb | 127 | err = dpm_suspend_end(PMSG_FREEZE); |
2ed8d2b3 | 128 | if (err) { |
283c0972 | 129 | pr_err("dpm_suspend_end failed: %d\n", err); |
186bab1c | 130 | si.cancelled = 0; |
65f63384 | 131 | goto out_resume; |
2ed8d2b3 RW |
132 | } |
133 | ||
ceb18029 IC |
134 | si.cancelled = 1; |
135 | ||
b056b6a0 | 136 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); |
922cc38a | 137 | |
1b647823 DV |
138 | /* Resume console as early as possible. */ |
139 | if (!si.cancelled) | |
140 | xen_console_resume(); | |
141 | ||
cd979883 SG |
142 | raw_notifier_call_chain(&xen_resume_notifier, 0, NULL); |
143 | ||
cf579dfb | 144 | dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
922cc38a | 145 | |
0e91398f | 146 | if (err) { |
283c0972 | 147 | pr_err("failed to start xen_suspend: %d\n", err); |
ceb18029 | 148 | si.cancelled = 1; |
0e91398f JF |
149 | } |
150 | ||
c5cae661 | 151 | out_resume: |
ceb18029 | 152 | if (!si.cancelled) { |
ad55db9f | 153 | xen_arch_resume(); |
de5b31bd | 154 | xs_resume(); |
ad55db9f | 155 | } else |
de5b31bd | 156 | xs_suspend_cancel(); |
0e91398f | 157 | |
b3e96c0c | 158 | dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
0e91398f | 159 | |
65f63384 | 160 | out_thaw: |
0e91398f | 161 | thaw_processes(); |
65f63384 | 162 | out: |
0e91398f JF |
163 | shutting_down = SHUTDOWN_INVALID; |
164 | } | |
1f112cee | 165 | #endif /* CONFIG_HIBERNATE_CALLBACKS */ |
3e2b8fbe | 166 | |
55271723 IC |
167 | struct shutdown_handler { |
168 | const char *command; | |
169 | void (*cb)(void); | |
170 | }; | |
171 | ||
eb47f712 KRW |
172 | static int poweroff_nb(struct notifier_block *cb, unsigned long code, void *unused) |
173 | { | |
174 | switch (code) { | |
175 | case SYS_DOWN: | |
176 | case SYS_HALT: | |
177 | case SYS_POWER_OFF: | |
178 | shutting_down = SHUTDOWN_POWEROFF; | |
179 | default: | |
180 | break; | |
181 | } | |
182 | return NOTIFY_DONE; | |
183 | } | |
55271723 IC |
184 | static void do_poweroff(void) |
185 | { | |
eb47f712 KRW |
186 | switch (system_state) { |
187 | case SYSTEM_BOOTING: | |
188 | orderly_poweroff(true); | |
189 | break; | |
190 | case SYSTEM_RUNNING: | |
191 | orderly_poweroff(false); | |
192 | break; | |
193 | default: | |
194 | /* Don't do it when we are halting/rebooting. */ | |
195 | pr_info("Ignoring Xen toolstack shutdown.\n"); | |
196 | break; | |
197 | } | |
55271723 IC |
198 | } |
199 | ||
200 | static void do_reboot(void) | |
201 | { | |
202 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
203 | ctrl_alt_del(); | |
204 | } | |
205 | ||
3e2b8fbe JF |
206 | static void shutdown_handler(struct xenbus_watch *watch, |
207 | const char **vec, unsigned int len) | |
208 | { | |
209 | char *str; | |
210 | struct xenbus_transaction xbt; | |
211 | int err; | |
55271723 IC |
212 | static struct shutdown_handler handlers[] = { |
213 | { "poweroff", do_poweroff }, | |
214 | { "halt", do_poweroff }, | |
215 | { "reboot", do_reboot }, | |
1f112cee | 216 | #ifdef CONFIG_HIBERNATE_CALLBACKS |
55271723 IC |
217 | { "suspend", do_suspend }, |
218 | #endif | |
219 | {NULL, NULL}, | |
220 | }; | |
221 | static struct shutdown_handler *handler; | |
3e2b8fbe JF |
222 | |
223 | if (shutting_down != SHUTDOWN_INVALID) | |
224 | return; | |
225 | ||
226 | again: | |
227 | err = xenbus_transaction_start(&xbt); | |
228 | if (err) | |
229 | return; | |
230 | ||
231 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
232 | /* Ignore read errors and empty reads. */ | |
233 | if (XENBUS_IS_ERR_READ(str)) { | |
234 | xenbus_transaction_end(xbt, 1); | |
235 | return; | |
236 | } | |
237 | ||
55271723 IC |
238 | for (handler = &handlers[0]; handler->command; handler++) { |
239 | if (strcmp(str, handler->command) == 0) | |
240 | break; | |
241 | } | |
242 | ||
243 | /* Only acknowledge commands which we are prepared to handle. */ | |
244 | if (handler->cb) | |
245 | xenbus_write(xbt, "control", "shutdown", ""); | |
3e2b8fbe JF |
246 | |
247 | err = xenbus_transaction_end(xbt, 0); | |
248 | if (err == -EAGAIN) { | |
249 | kfree(str); | |
250 | goto again; | |
251 | } | |
252 | ||
55271723 IC |
253 | if (handler->cb) { |
254 | handler->cb(); | |
0e91398f | 255 | } else { |
283c0972 | 256 | pr_info("Ignoring shutdown request: %s\n", str); |
3e2b8fbe JF |
257 | shutting_down = SHUTDOWN_INVALID; |
258 | } | |
259 | ||
260 | kfree(str); | |
261 | } | |
262 | ||
f3bc3189 | 263 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
264 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, |
265 | unsigned int len) | |
266 | { | |
267 | char sysrq_key = '\0'; | |
268 | struct xenbus_transaction xbt; | |
269 | int err; | |
270 | ||
271 | again: | |
272 | err = xenbus_transaction_start(&xbt); | |
273 | if (err) | |
274 | return; | |
275 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
283c0972 | 276 | pr_err("Unable to read sysrq code in control/sysrq\n"); |
3e2b8fbe JF |
277 | xenbus_transaction_end(xbt, 1); |
278 | return; | |
279 | } | |
280 | ||
281 | if (sysrq_key != '\0') | |
282 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
283 | ||
284 | err = xenbus_transaction_end(xbt, 0); | |
285 | if (err == -EAGAIN) | |
286 | goto again; | |
287 | ||
288 | if (sysrq_key != '\0') | |
f335397d | 289 | handle_sysrq(sysrq_key); |
3e2b8fbe JF |
290 | } |
291 | ||
3e2b8fbe JF |
292 | static struct xenbus_watch sysrq_watch = { |
293 | .node = "control/sysrq", | |
294 | .callback = sysrq_handler | |
295 | }; | |
f3bc3189 RD |
296 | #endif |
297 | ||
298 | static struct xenbus_watch shutdown_watch = { | |
299 | .node = "control/shutdown", | |
300 | .callback = shutdown_handler | |
301 | }; | |
3e2b8fbe | 302 | |
eb47f712 KRW |
303 | static struct notifier_block xen_reboot_nb = { |
304 | .notifier_call = poweroff_nb, | |
305 | }; | |
306 | ||
3e2b8fbe JF |
307 | static int setup_shutdown_watcher(void) |
308 | { | |
309 | int err; | |
310 | ||
311 | err = register_xenbus_watch(&shutdown_watch); | |
312 | if (err) { | |
283c0972 | 313 | pr_err("Failed to set shutdown watcher\n"); |
3e2b8fbe JF |
314 | return err; |
315 | } | |
316 | ||
eb47f712 | 317 | |
f3bc3189 | 318 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
319 | err = register_xenbus_watch(&sysrq_watch); |
320 | if (err) { | |
283c0972 | 321 | pr_err("Failed to set sysrq watcher\n"); |
3e2b8fbe JF |
322 | return err; |
323 | } | |
f3bc3189 | 324 | #endif |
3e2b8fbe JF |
325 | |
326 | return 0; | |
327 | } | |
328 | ||
329 | static int shutdown_event(struct notifier_block *notifier, | |
330 | unsigned long event, | |
331 | void *data) | |
332 | { | |
333 | setup_shutdown_watcher(); | |
334 | return NOTIFY_DONE; | |
335 | } | |
336 | ||
016b6f5f | 337 | int xen_setup_shutdown_event(void) |
3e2b8fbe JF |
338 | { |
339 | static struct notifier_block xenstore_notifier = { | |
340 | .notifier_call = shutdown_event | |
341 | }; | |
702d4eb9 SS |
342 | |
343 | if (!xen_domain()) | |
344 | return -ENODEV; | |
3e2b8fbe | 345 | register_xenstore_notifier(&xenstore_notifier); |
eb47f712 | 346 | register_reboot_notifier(&xen_reboot_nb); |
3e2b8fbe JF |
347 | |
348 | return 0; | |
349 | } | |
183d03cc | 350 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 351 | |
702d4eb9 | 352 | subsys_initcall(xen_setup_shutdown_event); |