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Commit | Line | Data |
---|---|---|
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> | |
a9fd60e2 | 22 | #include <xen/page.h> |
0e91398f | 23 | #include <xen/xen-ops.h> |
3e2b8fbe | 24 | |
0e91398f | 25 | #include <asm/xen/hypercall.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 | 82 | si->cancelled = HYPERVISOR_suspend(xen_pv_domain() |
0df4f266 | 83 | ? virt_to_gfn(xen_start_info) |
aa8532c3 | 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 | ||
2b953a5e BO |
134 | xen_arch_suspend(); |
135 | ||
ceb18029 IC |
136 | si.cancelled = 1; |
137 | ||
b056b6a0 | 138 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); |
922cc38a | 139 | |
1b647823 DV |
140 | /* Resume console as early as possible. */ |
141 | if (!si.cancelled) | |
142 | xen_console_resume(); | |
143 | ||
cd979883 SG |
144 | raw_notifier_call_chain(&xen_resume_notifier, 0, NULL); |
145 | ||
cf579dfb | 146 | dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
922cc38a | 147 | |
0e91398f | 148 | if (err) { |
283c0972 | 149 | pr_err("failed to start xen_suspend: %d\n", err); |
ceb18029 | 150 | si.cancelled = 1; |
0e91398f JF |
151 | } |
152 | ||
2b953a5e BO |
153 | xen_arch_resume(); |
154 | ||
c5cae661 | 155 | out_resume: |
2b953a5e | 156 | if (!si.cancelled) |
de5b31bd | 157 | xs_resume(); |
2b953a5e | 158 | else |
de5b31bd | 159 | xs_suspend_cancel(); |
0e91398f | 160 | |
b3e96c0c | 161 | dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
0e91398f | 162 | |
65f63384 | 163 | out_thaw: |
0e91398f | 164 | thaw_processes(); |
65f63384 | 165 | out: |
0e91398f JF |
166 | shutting_down = SHUTDOWN_INVALID; |
167 | } | |
1f112cee | 168 | #endif /* CONFIG_HIBERNATE_CALLBACKS */ |
3e2b8fbe | 169 | |
55271723 | 170 | struct shutdown_handler { |
44b3c7af JG |
171 | #define SHUTDOWN_CMD_SIZE 11 |
172 | const char command[SHUTDOWN_CMD_SIZE]; | |
173 | bool flag; | |
55271723 IC |
174 | void (*cb)(void); |
175 | }; | |
176 | ||
eb47f712 KRW |
177 | static int poweroff_nb(struct notifier_block *cb, unsigned long code, void *unused) |
178 | { | |
179 | switch (code) { | |
180 | case SYS_DOWN: | |
181 | case SYS_HALT: | |
182 | case SYS_POWER_OFF: | |
183 | shutting_down = SHUTDOWN_POWEROFF; | |
184 | default: | |
185 | break; | |
186 | } | |
187 | return NOTIFY_DONE; | |
188 | } | |
55271723 IC |
189 | static void do_poweroff(void) |
190 | { | |
eb47f712 KRW |
191 | switch (system_state) { |
192 | case SYSTEM_BOOTING: | |
69a78ff2 | 193 | case SYSTEM_SCHEDULING: |
eb47f712 KRW |
194 | orderly_poweroff(true); |
195 | break; | |
196 | case SYSTEM_RUNNING: | |
197 | orderly_poweroff(false); | |
198 | break; | |
199 | default: | |
200 | /* Don't do it when we are halting/rebooting. */ | |
201 | pr_info("Ignoring Xen toolstack shutdown.\n"); | |
202 | break; | |
203 | } | |
55271723 IC |
204 | } |
205 | ||
206 | static void do_reboot(void) | |
207 | { | |
208 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
209 | ctrl_alt_del(); | |
210 | } | |
211 | ||
44b3c7af JG |
212 | static struct shutdown_handler shutdown_handlers[] = { |
213 | { "poweroff", true, do_poweroff }, | |
214 | { "halt", false, do_poweroff }, | |
215 | { "reboot", true, do_reboot }, | |
216 | #ifdef CONFIG_HIBERNATE_CALLBACKS | |
217 | { "suspend", true, do_suspend }, | |
218 | #endif | |
219 | }; | |
220 | ||
3e2b8fbe | 221 | static void shutdown_handler(struct xenbus_watch *watch, |
5584ea25 | 222 | const char *path, const char *token) |
3e2b8fbe JF |
223 | { |
224 | char *str; | |
225 | struct xenbus_transaction xbt; | |
226 | int err; | |
44b3c7af | 227 | int idx; |
3e2b8fbe JF |
228 | |
229 | if (shutting_down != SHUTDOWN_INVALID) | |
230 | return; | |
231 | ||
232 | again: | |
233 | err = xenbus_transaction_start(&xbt); | |
234 | if (err) | |
235 | return; | |
236 | ||
237 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
238 | /* Ignore read errors and empty reads. */ | |
239 | if (XENBUS_IS_ERR_READ(str)) { | |
240 | xenbus_transaction_end(xbt, 1); | |
241 | return; | |
242 | } | |
243 | ||
44b3c7af JG |
244 | for (idx = 0; idx < ARRAY_SIZE(shutdown_handlers); idx++) { |
245 | if (strcmp(str, shutdown_handlers[idx].command) == 0) | |
55271723 IC |
246 | break; |
247 | } | |
248 | ||
249 | /* Only acknowledge commands which we are prepared to handle. */ | |
44b3c7af | 250 | if (idx < ARRAY_SIZE(shutdown_handlers)) |
55271723 | 251 | xenbus_write(xbt, "control", "shutdown", ""); |
3e2b8fbe JF |
252 | |
253 | err = xenbus_transaction_end(xbt, 0); | |
254 | if (err == -EAGAIN) { | |
255 | kfree(str); | |
256 | goto again; | |
257 | } | |
258 | ||
44b3c7af JG |
259 | if (idx < ARRAY_SIZE(shutdown_handlers)) { |
260 | shutdown_handlers[idx].cb(); | |
0e91398f | 261 | } else { |
283c0972 | 262 | pr_info("Ignoring shutdown request: %s\n", str); |
3e2b8fbe JF |
263 | shutting_down = SHUTDOWN_INVALID; |
264 | } | |
265 | ||
266 | kfree(str); | |
267 | } | |
268 | ||
f3bc3189 | 269 | #ifdef CONFIG_MAGIC_SYSRQ |
5584ea25 JG |
270 | static void sysrq_handler(struct xenbus_watch *watch, const char *path, |
271 | const char *token) | |
3e2b8fbe JF |
272 | { |
273 | char sysrq_key = '\0'; | |
274 | struct xenbus_transaction xbt; | |
275 | int err; | |
276 | ||
277 | again: | |
278 | err = xenbus_transaction_start(&xbt); | |
279 | if (err) | |
280 | return; | |
4e93b648 JG |
281 | err = xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key); |
282 | if (err < 0) { | |
283 | /* | |
284 | * The Xenstore watch fires directly after registering it and | |
285 | * after a suspend/resume cycle. So ENOENT is no error but | |
286 | * might happen in those cases. | |
287 | */ | |
288 | if (err != -ENOENT) | |
289 | pr_err("Error %d reading sysrq code in control/sysrq\n", | |
290 | err); | |
3e2b8fbe JF |
291 | xenbus_transaction_end(xbt, 1); |
292 | return; | |
293 | } | |
294 | ||
295 | if (sysrq_key != '\0') | |
296 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
297 | ||
298 | err = xenbus_transaction_end(xbt, 0); | |
299 | if (err == -EAGAIN) | |
300 | goto again; | |
301 | ||
302 | if (sysrq_key != '\0') | |
f335397d | 303 | handle_sysrq(sysrq_key); |
3e2b8fbe JF |
304 | } |
305 | ||
3e2b8fbe JF |
306 | static struct xenbus_watch sysrq_watch = { |
307 | .node = "control/sysrq", | |
308 | .callback = sysrq_handler | |
309 | }; | |
f3bc3189 RD |
310 | #endif |
311 | ||
312 | static struct xenbus_watch shutdown_watch = { | |
313 | .node = "control/shutdown", | |
314 | .callback = shutdown_handler | |
315 | }; | |
3e2b8fbe | 316 | |
eb47f712 KRW |
317 | static struct notifier_block xen_reboot_nb = { |
318 | .notifier_call = poweroff_nb, | |
319 | }; | |
320 | ||
3e2b8fbe JF |
321 | static int setup_shutdown_watcher(void) |
322 | { | |
323 | int err; | |
44b3c7af JG |
324 | int idx; |
325 | #define FEATURE_PATH_SIZE (SHUTDOWN_CMD_SIZE + sizeof("feature-")) | |
326 | char node[FEATURE_PATH_SIZE]; | |
3e2b8fbe JF |
327 | |
328 | err = register_xenbus_watch(&shutdown_watch); | |
329 | if (err) { | |
283c0972 | 330 | pr_err("Failed to set shutdown watcher\n"); |
3e2b8fbe JF |
331 | return err; |
332 | } | |
333 | ||
eb47f712 | 334 | |
f3bc3189 | 335 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
336 | err = register_xenbus_watch(&sysrq_watch); |
337 | if (err) { | |
283c0972 | 338 | pr_err("Failed to set sysrq watcher\n"); |
3e2b8fbe JF |
339 | return err; |
340 | } | |
f3bc3189 | 341 | #endif |
3e2b8fbe | 342 | |
44b3c7af JG |
343 | for (idx = 0; idx < ARRAY_SIZE(shutdown_handlers); idx++) { |
344 | if (!shutdown_handlers[idx].flag) | |
345 | continue; | |
346 | snprintf(node, FEATURE_PATH_SIZE, "feature-%s", | |
347 | shutdown_handlers[idx].command); | |
348 | xenbus_printf(XBT_NIL, "control", node, "%u", 1); | |
349 | } | |
350 | ||
3e2b8fbe JF |
351 | return 0; |
352 | } | |
353 | ||
354 | static int shutdown_event(struct notifier_block *notifier, | |
355 | unsigned long event, | |
356 | void *data) | |
357 | { | |
358 | setup_shutdown_watcher(); | |
359 | return NOTIFY_DONE; | |
360 | } | |
361 | ||
016b6f5f | 362 | int xen_setup_shutdown_event(void) |
3e2b8fbe JF |
363 | { |
364 | static struct notifier_block xenstore_notifier = { | |
365 | .notifier_call = shutdown_event | |
366 | }; | |
702d4eb9 SS |
367 | |
368 | if (!xen_domain()) | |
369 | return -ENODEV; | |
3e2b8fbe | 370 | register_xenstore_notifier(&xenstore_notifier); |
eb47f712 | 371 | register_reboot_notifier(&xen_reboot_nb); |
3e2b8fbe JF |
372 | |
373 | return 0; | |
374 | } | |
183d03cc | 375 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 376 | |
702d4eb9 | 377 | subsys_initcall(xen_setup_shutdown_event); |