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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; | |
36b401e2 | 44 | unsigned long arg; /* extra hypercall argument */ |
55fb4ace IC |
45 | void (*pre)(void); |
46 | void (*post)(int cancelled); | |
ceb18029 IC |
47 | }; |
48 | ||
65e053a7 | 49 | #ifdef CONFIG_HIBERNATE_CALLBACKS |
07af3810 | 50 | static void xen_hvm_post_suspend(int cancelled) |
82043bb6 | 51 | { |
07af3810 | 52 | xen_arch_hvm_post_suspend(cancelled); |
82043bb6 IC |
53 | gnttab_resume(); |
54 | } | |
55 | ||
56 | static void xen_pre_suspend(void) | |
57 | { | |
58 | xen_mm_pin_all(); | |
59 | gnttab_suspend(); | |
07af3810 | 60 | xen_arch_pre_suspend(); |
82043bb6 IC |
61 | } |
62 | ||
07af3810 | 63 | static void xen_post_suspend(int cancelled) |
82043bb6 | 64 | { |
07af3810 | 65 | xen_arch_post_suspend(cancelled); |
82043bb6 IC |
66 | gnttab_resume(); |
67 | xen_mm_unpin_all(); | |
68 | } | |
69 | ||
016b6f5f SS |
70 | static int xen_suspend(void *data) |
71 | { | |
ceb18029 | 72 | struct suspend_info *si = data; |
359cdd3f | 73 | int err; |
0e91398f JF |
74 | |
75 | BUG_ON(!irqs_disabled()); | |
76 | ||
2e711c04 | 77 | err = syscore_suspend(); |
770824bd | 78 | if (err) { |
283c0972 | 79 | pr_err("%s: system core suspend failed: %d\n", __func__, err); |
770824bd RW |
80 | return err; |
81 | } | |
359cdd3f | 82 | |
55fb4ace IC |
83 | if (si->pre) |
84 | si->pre(); | |
0e91398f JF |
85 | |
86 | /* | |
87 | * This hypercall returns 1 if suspend was cancelled | |
88 | * or the domain was merely checkpointed, and 0 if it | |
89 | * is resuming in a new domain. | |
90 | */ | |
36b401e2 | 91 | si->cancelled = HYPERVISOR_suspend(si->arg); |
0e91398f | 92 | |
55fb4ace IC |
93 | if (si->post) |
94 | si->post(si->cancelled); | |
0e91398f | 95 | |
ceb18029 | 96 | if (!si->cancelled) { |
0e91398f JF |
97 | xen_irq_resume(); |
98 | xen_console_resume(); | |
ad55db9f | 99 | xen_timer_resume(); |
0e91398f JF |
100 | } |
101 | ||
19234c08 | 102 | syscore_resume(); |
1e6fcf84 | 103 | |
0e91398f JF |
104 | return 0; |
105 | } | |
106 | ||
107 | static void do_suspend(void) | |
108 | { | |
109 | int err; | |
ceb18029 | 110 | struct suspend_info si; |
0e91398f JF |
111 | |
112 | shutting_down = SHUTDOWN_SUSPEND; | |
113 | ||
114 | #ifdef CONFIG_PREEMPT | |
115 | /* If the kernel is preemptible, we need to freeze all the processes | |
116 | to prevent them from being in the middle of a pagetable update | |
117 | during suspend. */ | |
118 | err = freeze_processes(); | |
119 | if (err) { | |
283c0972 | 120 | pr_err("%s: freeze failed %d\n", __func__, err); |
3fc1f1e2 | 121 | goto out; |
0e91398f JF |
122 | } |
123 | #endif | |
124 | ||
b3e96c0c | 125 | err = dpm_suspend_start(PMSG_FREEZE); |
0e91398f | 126 | if (err) { |
283c0972 | 127 | pr_err("%s: dpm_suspend_start %d\n", __func__, err); |
65f63384 | 128 | goto out_thaw; |
0e91398f JF |
129 | } |
130 | ||
c5cae661 IC |
131 | printk(KERN_DEBUG "suspending xenstore...\n"); |
132 | xs_suspend(); | |
133 | ||
cf579dfb | 134 | err = dpm_suspend_end(PMSG_FREEZE); |
2ed8d2b3 | 135 | if (err) { |
283c0972 | 136 | pr_err("dpm_suspend_end failed: %d\n", err); |
186bab1c | 137 | si.cancelled = 0; |
65f63384 | 138 | goto out_resume; |
2ed8d2b3 RW |
139 | } |
140 | ||
ceb18029 IC |
141 | si.cancelled = 1; |
142 | ||
55fb4ace | 143 | if (xen_hvm_domain()) { |
36b401e2 | 144 | si.arg = 0UL; |
55fb4ace IC |
145 | si.pre = NULL; |
146 | si.post = &xen_hvm_post_suspend; | |
147 | } else { | |
36b401e2 | 148 | si.arg = virt_to_mfn(xen_start_info); |
55fb4ace IC |
149 | si.pre = &xen_pre_suspend; |
150 | si.post = &xen_post_suspend; | |
151 | } | |
36b401e2 | 152 | |
b056b6a0 | 153 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); |
922cc38a | 154 | |
cf579dfb | 155 | dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
922cc38a | 156 | |
0e91398f | 157 | if (err) { |
283c0972 | 158 | pr_err("failed to start xen_suspend: %d\n", err); |
ceb18029 | 159 | si.cancelled = 1; |
0e91398f JF |
160 | } |
161 | ||
c5cae661 | 162 | out_resume: |
ceb18029 | 163 | if (!si.cancelled) { |
ad55db9f | 164 | xen_arch_resume(); |
de5b31bd | 165 | xs_resume(); |
ad55db9f | 166 | } else |
de5b31bd | 167 | xs_suspend_cancel(); |
0e91398f | 168 | |
b3e96c0c | 169 | dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
0e91398f | 170 | |
65f63384 | 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 { |
283c0972 | 247 | pr_info("Ignoring shutdown request: %s\n", str); |
3e2b8fbe JF |
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)) { | |
283c0972 | 267 | pr_err("Unable to read sysrq code in control/sysrq\n"); |
3e2b8fbe JF |
268 | xenbus_transaction_end(xbt, 1); |
269 | return; | |
270 | } | |
271 | ||
272 | if (sysrq_key != '\0') | |
273 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
274 | ||
275 | err = xenbus_transaction_end(xbt, 0); | |
276 | if (err == -EAGAIN) | |
277 | goto again; | |
278 | ||
279 | if (sysrq_key != '\0') | |
f335397d | 280 | handle_sysrq(sysrq_key); |
3e2b8fbe JF |
281 | } |
282 | ||
3e2b8fbe JF |
283 | static struct xenbus_watch sysrq_watch = { |
284 | .node = "control/sysrq", | |
285 | .callback = sysrq_handler | |
286 | }; | |
f3bc3189 RD |
287 | #endif |
288 | ||
289 | static struct xenbus_watch shutdown_watch = { | |
290 | .node = "control/shutdown", | |
291 | .callback = shutdown_handler | |
292 | }; | |
3e2b8fbe JF |
293 | |
294 | static int setup_shutdown_watcher(void) | |
295 | { | |
296 | int err; | |
297 | ||
298 | err = register_xenbus_watch(&shutdown_watch); | |
299 | if (err) { | |
283c0972 | 300 | pr_err("Failed to set shutdown watcher\n"); |
3e2b8fbe JF |
301 | return err; |
302 | } | |
303 | ||
f3bc3189 | 304 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
305 | err = register_xenbus_watch(&sysrq_watch); |
306 | if (err) { | |
283c0972 | 307 | pr_err("Failed to set sysrq watcher\n"); |
3e2b8fbe JF |
308 | return err; |
309 | } | |
f3bc3189 | 310 | #endif |
3e2b8fbe JF |
311 | |
312 | return 0; | |
313 | } | |
314 | ||
315 | static int shutdown_event(struct notifier_block *notifier, | |
316 | unsigned long event, | |
317 | void *data) | |
318 | { | |
319 | setup_shutdown_watcher(); | |
320 | return NOTIFY_DONE; | |
321 | } | |
322 | ||
016b6f5f | 323 | int xen_setup_shutdown_event(void) |
3e2b8fbe JF |
324 | { |
325 | static struct notifier_block xenstore_notifier = { | |
326 | .notifier_call = shutdown_event | |
327 | }; | |
702d4eb9 SS |
328 | |
329 | if (!xen_domain()) | |
330 | return -ENODEV; | |
3e2b8fbe JF |
331 | register_xenstore_notifier(&xenstore_notifier); |
332 | ||
333 | return 0; | |
334 | } | |
183d03cc | 335 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 336 | |
702d4eb9 | 337 | subsys_initcall(xen_setup_shutdown_event); |