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Commit | Line | Data |
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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> | |
3e2b8fbe | 11 | |
016b6f5f | 12 | #include <xen/xen.h> |
3e2b8fbe | 13 | #include <xen/xenbus.h> |
0e91398f JF |
14 | #include <xen/grant_table.h> |
15 | #include <xen/events.h> | |
16 | #include <xen/hvc-console.h> | |
17 | #include <xen/xen-ops.h> | |
3e2b8fbe | 18 | |
0e91398f JF |
19 | #include <asm/xen/hypercall.h> |
20 | #include <asm/xen/page.h> | |
016b6f5f | 21 | #include <asm/xen/hypervisor.h> |
0e91398f JF |
22 | |
23 | enum shutdown_state { | |
24 | SHUTDOWN_INVALID = -1, | |
25 | SHUTDOWN_POWEROFF = 0, | |
26 | SHUTDOWN_SUSPEND = 2, | |
27 | /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only | |
28 | report a crash, not be instructed to crash! | |
29 | HALT is the same as POWEROFF, as far as we're concerned. The tools use | |
30 | the distinction when we return the reason code to them. */ | |
31 | SHUTDOWN_HALT = 4, | |
32 | }; | |
3e2b8fbe JF |
33 | |
34 | /* Ignore multiple shutdown requests. */ | |
0e91398f JF |
35 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
36 | ||
c7827728 | 37 | #ifdef CONFIG_PM_SLEEP |
016b6f5f | 38 | static int xen_hvm_suspend(void *data) |
0e91398f | 39 | { |
016b6f5f | 40 | struct sched_shutdown r = { .reason = SHUTDOWN_suspend }; |
0e91398f | 41 | int *cancelled = data; |
016b6f5f SS |
42 | |
43 | BUG_ON(!irqs_disabled()); | |
44 | ||
45 | *cancelled = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r); | |
46 | ||
47 | xen_hvm_post_suspend(*cancelled); | |
48 | gnttab_resume(); | |
49 | ||
50 | if (!*cancelled) { | |
51 | xen_irq_resume(); | |
52 | xen_timer_resume(); | |
53 | } | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | static int xen_suspend(void *data) | |
59 | { | |
359cdd3f | 60 | int err; |
016b6f5f | 61 | int *cancelled = data; |
0e91398f JF |
62 | |
63 | BUG_ON(!irqs_disabled()); | |
64 | ||
770824bd RW |
65 | err = sysdev_suspend(PMSG_SUSPEND); |
66 | if (err) { | |
67 | printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n", | |
68 | err); | |
770824bd RW |
69 | return err; |
70 | } | |
359cdd3f | 71 | |
0e91398f JF |
72 | xen_mm_pin_all(); |
73 | gnttab_suspend(); | |
0e91398f JF |
74 | xen_pre_suspend(); |
75 | ||
76 | /* | |
77 | * This hypercall returns 1 if suspend was cancelled | |
78 | * or the domain was merely checkpointed, and 0 if it | |
79 | * is resuming in a new domain. | |
80 | */ | |
81 | *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); | |
82 | ||
83 | xen_post_suspend(*cancelled); | |
0e91398f JF |
84 | gnttab_resume(); |
85 | xen_mm_unpin_all(); | |
86 | ||
87 | if (!*cancelled) { | |
88 | xen_irq_resume(); | |
89 | xen_console_resume(); | |
ad55db9f | 90 | xen_timer_resume(); |
0e91398f JF |
91 | } |
92 | ||
1e6fcf84 | 93 | sysdev_resume(); |
1e6fcf84 | 94 | |
0e91398f JF |
95 | return 0; |
96 | } | |
97 | ||
98 | static void do_suspend(void) | |
99 | { | |
100 | int err; | |
101 | int cancelled = 1; | |
102 | ||
103 | shutting_down = SHUTDOWN_SUSPEND; | |
104 | ||
105 | #ifdef CONFIG_PREEMPT | |
106 | /* If the kernel is preemptible, we need to freeze all the processes | |
107 | to prevent them from being in the middle of a pagetable update | |
108 | during suspend. */ | |
109 | err = freeze_processes(); | |
110 | if (err) { | |
111 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
3fc1f1e2 | 112 | goto out; |
0e91398f JF |
113 | } |
114 | #endif | |
115 | ||
d1616302 | 116 | err = dpm_suspend_start(PMSG_SUSPEND); |
0e91398f | 117 | if (err) { |
d1616302 | 118 | printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); |
65f63384 | 119 | goto out_thaw; |
0e91398f JF |
120 | } |
121 | ||
c5cae661 IC |
122 | printk(KERN_DEBUG "suspending xenstore...\n"); |
123 | xs_suspend(); | |
124 | ||
d1616302 | 125 | err = dpm_suspend_noirq(PMSG_SUSPEND); |
2ed8d2b3 | 126 | if (err) { |
d1616302 | 127 | printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err); |
65f63384 | 128 | goto out_resume; |
2ed8d2b3 RW |
129 | } |
130 | ||
016b6f5f SS |
131 | if (xen_hvm_domain()) |
132 | err = stop_machine(xen_hvm_suspend, &cancelled, cpumask_of(0)); | |
133 | else | |
134 | err = stop_machine(xen_suspend, &cancelled, cpumask_of(0)); | |
922cc38a JF |
135 | |
136 | dpm_resume_noirq(PMSG_RESUME); | |
137 | ||
0e91398f JF |
138 | if (err) { |
139 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); | |
65f63384 | 140 | cancelled = 1; |
0e91398f JF |
141 | } |
142 | ||
c5cae661 | 143 | out_resume: |
ad55db9f IY |
144 | if (!cancelled) { |
145 | xen_arch_resume(); | |
de5b31bd | 146 | xs_resume(); |
ad55db9f | 147 | } else |
de5b31bd | 148 | xs_suspend_cancel(); |
0e91398f | 149 | |
d1616302 | 150 | dpm_resume_end(PMSG_RESUME); |
0e91398f | 151 | |
359cdd3f JF |
152 | /* Make sure timer events get retriggered on all CPUs */ |
153 | clock_was_set(); | |
65f63384 IC |
154 | |
155 | out_thaw: | |
0e91398f JF |
156 | #ifdef CONFIG_PREEMPT |
157 | thaw_processes(); | |
65f63384 | 158 | out: |
3fc1f1e2 | 159 | #endif |
0e91398f JF |
160 | shutting_down = SHUTDOWN_INVALID; |
161 | } | |
c7827728 | 162 | #endif /* CONFIG_PM_SLEEP */ |
3e2b8fbe JF |
163 | |
164 | static void shutdown_handler(struct xenbus_watch *watch, | |
165 | const char **vec, unsigned int len) | |
166 | { | |
167 | char *str; | |
168 | struct xenbus_transaction xbt; | |
169 | int err; | |
170 | ||
171 | if (shutting_down != SHUTDOWN_INVALID) | |
172 | return; | |
173 | ||
174 | again: | |
175 | err = xenbus_transaction_start(&xbt); | |
176 | if (err) | |
177 | return; | |
178 | ||
179 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
180 | /* Ignore read errors and empty reads. */ | |
181 | if (XENBUS_IS_ERR_READ(str)) { | |
182 | xenbus_transaction_end(xbt, 1); | |
183 | return; | |
184 | } | |
185 | ||
186 | xenbus_write(xbt, "control", "shutdown", ""); | |
187 | ||
188 | err = xenbus_transaction_end(xbt, 0); | |
189 | if (err == -EAGAIN) { | |
190 | kfree(str); | |
191 | goto again; | |
192 | } | |
193 | ||
194 | if (strcmp(str, "poweroff") == 0 || | |
0e91398f JF |
195 | strcmp(str, "halt") == 0) { |
196 | shutting_down = SHUTDOWN_POWEROFF; | |
3e2b8fbe | 197 | orderly_poweroff(false); |
0e91398f JF |
198 | } else if (strcmp(str, "reboot") == 0) { |
199 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
3e2b8fbe | 200 | ctrl_alt_del(); |
0e91398f JF |
201 | #ifdef CONFIG_PM_SLEEP |
202 | } else if (strcmp(str, "suspend") == 0) { | |
203 | do_suspend(); | |
204 | #endif | |
205 | } else { | |
3e2b8fbe JF |
206 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
207 | shutting_down = SHUTDOWN_INVALID; | |
208 | } | |
209 | ||
210 | kfree(str); | |
211 | } | |
212 | ||
f3bc3189 | 213 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
214 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, |
215 | unsigned int len) | |
216 | { | |
217 | char sysrq_key = '\0'; | |
218 | struct xenbus_transaction xbt; | |
219 | int err; | |
220 | ||
221 | again: | |
222 | err = xenbus_transaction_start(&xbt); | |
223 | if (err) | |
224 | return; | |
225 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
226 | printk(KERN_ERR "Unable to read sysrq code in " | |
227 | "control/sysrq\n"); | |
228 | xenbus_transaction_end(xbt, 1); | |
229 | return; | |
230 | } | |
231 | ||
232 | if (sysrq_key != '\0') | |
233 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
234 | ||
235 | err = xenbus_transaction_end(xbt, 0); | |
236 | if (err == -EAGAIN) | |
237 | goto again; | |
238 | ||
239 | if (sysrq_key != '\0') | |
240 | handle_sysrq(sysrq_key, NULL); | |
241 | } | |
242 | ||
3e2b8fbe JF |
243 | static struct xenbus_watch sysrq_watch = { |
244 | .node = "control/sysrq", | |
245 | .callback = sysrq_handler | |
246 | }; | |
f3bc3189 RD |
247 | #endif |
248 | ||
249 | static struct xenbus_watch shutdown_watch = { | |
250 | .node = "control/shutdown", | |
251 | .callback = shutdown_handler | |
252 | }; | |
3e2b8fbe JF |
253 | |
254 | static int setup_shutdown_watcher(void) | |
255 | { | |
256 | int err; | |
257 | ||
258 | err = register_xenbus_watch(&shutdown_watch); | |
259 | if (err) { | |
260 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
261 | return err; | |
262 | } | |
263 | ||
f3bc3189 | 264 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
265 | err = register_xenbus_watch(&sysrq_watch); |
266 | if (err) { | |
267 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
268 | return err; | |
269 | } | |
f3bc3189 | 270 | #endif |
3e2b8fbe JF |
271 | |
272 | return 0; | |
273 | } | |
274 | ||
275 | static int shutdown_event(struct notifier_block *notifier, | |
276 | unsigned long event, | |
277 | void *data) | |
278 | { | |
279 | setup_shutdown_watcher(); | |
280 | return NOTIFY_DONE; | |
281 | } | |
282 | ||
016b6f5f SS |
283 | static int __init __setup_shutdown_event(void) |
284 | { | |
285 | /* Delay initialization in the PV on HVM case */ | |
286 | if (xen_hvm_domain()) | |
287 | return 0; | |
288 | ||
289 | if (!xen_pv_domain()) | |
290 | return -ENODEV; | |
291 | ||
292 | return xen_setup_shutdown_event(); | |
293 | } | |
294 | ||
295 | int xen_setup_shutdown_event(void) | |
3e2b8fbe JF |
296 | { |
297 | static struct notifier_block xenstore_notifier = { | |
298 | .notifier_call = shutdown_event | |
299 | }; | |
300 | register_xenstore_notifier(&xenstore_notifier); | |
301 | ||
302 | return 0; | |
303 | } | |
183d03cc | 304 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 305 | |
016b6f5f | 306 | subsys_initcall(__setup_shutdown_event); |