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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 | { |
8dd38383 | 40 | int err; |
016b6f5f | 41 | struct sched_shutdown r = { .reason = SHUTDOWN_suspend }; |
0e91398f | 42 | int *cancelled = data; |
016b6f5f SS |
43 | |
44 | BUG_ON(!irqs_disabled()); | |
45 | ||
8dd38383 IC |
46 | err = sysdev_suspend(PMSG_SUSPEND); |
47 | if (err) { | |
48 | printk(KERN_ERR "xen_hvm_suspend: sysdev_suspend failed: %d\n", | |
49 | err); | |
50 | return err; | |
51 | } | |
52 | ||
016b6f5f SS |
53 | *cancelled = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r); |
54 | ||
55 | xen_hvm_post_suspend(*cancelled); | |
56 | gnttab_resume(); | |
57 | ||
58 | if (!*cancelled) { | |
59 | xen_irq_resume(); | |
6411fe69 | 60 | xen_console_resume(); |
016b6f5f SS |
61 | xen_timer_resume(); |
62 | } | |
63 | ||
8dd38383 IC |
64 | sysdev_resume(); |
65 | ||
016b6f5f SS |
66 | return 0; |
67 | } | |
68 | ||
69 | static int xen_suspend(void *data) | |
70 | { | |
359cdd3f | 71 | int err; |
016b6f5f | 72 | int *cancelled = data; |
0e91398f JF |
73 | |
74 | BUG_ON(!irqs_disabled()); | |
75 | ||
770824bd RW |
76 | err = sysdev_suspend(PMSG_SUSPEND); |
77 | if (err) { | |
78 | printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n", | |
79 | err); | |
770824bd RW |
80 | return err; |
81 | } | |
359cdd3f | 82 | |
0e91398f JF |
83 | xen_mm_pin_all(); |
84 | gnttab_suspend(); | |
0e91398f JF |
85 | xen_pre_suspend(); |
86 | ||
87 | /* | |
88 | * This hypercall returns 1 if suspend was cancelled | |
89 | * or the domain was merely checkpointed, and 0 if it | |
90 | * is resuming in a new domain. | |
91 | */ | |
92 | *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); | |
93 | ||
94 | xen_post_suspend(*cancelled); | |
0e91398f JF |
95 | gnttab_resume(); |
96 | xen_mm_unpin_all(); | |
97 | ||
98 | if (!*cancelled) { | |
99 | xen_irq_resume(); | |
100 | xen_console_resume(); | |
ad55db9f | 101 | xen_timer_resume(); |
0e91398f JF |
102 | } |
103 | ||
1e6fcf84 | 104 | sysdev_resume(); |
1e6fcf84 | 105 | |
0e91398f JF |
106 | return 0; |
107 | } | |
108 | ||
109 | static void do_suspend(void) | |
110 | { | |
111 | int err; | |
112 | int cancelled = 1; | |
113 | ||
114 | shutting_down = SHUTDOWN_SUSPEND; | |
115 | ||
116 | #ifdef CONFIG_PREEMPT | |
117 | /* If the kernel is preemptible, we need to freeze all the processes | |
118 | to prevent them from being in the middle of a pagetable update | |
119 | during suspend. */ | |
120 | err = freeze_processes(); | |
121 | if (err) { | |
122 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
3fc1f1e2 | 123 | goto out; |
0e91398f JF |
124 | } |
125 | #endif | |
126 | ||
d1616302 | 127 | err = dpm_suspend_start(PMSG_SUSPEND); |
0e91398f | 128 | if (err) { |
d1616302 | 129 | printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); |
65f63384 | 130 | goto out_thaw; |
0e91398f JF |
131 | } |
132 | ||
c5cae661 IC |
133 | printk(KERN_DEBUG "suspending xenstore...\n"); |
134 | xs_suspend(); | |
135 | ||
d1616302 | 136 | err = dpm_suspend_noirq(PMSG_SUSPEND); |
2ed8d2b3 | 137 | if (err) { |
d1616302 | 138 | printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err); |
65f63384 | 139 | goto out_resume; |
2ed8d2b3 RW |
140 | } |
141 | ||
016b6f5f SS |
142 | if (xen_hvm_domain()) |
143 | err = stop_machine(xen_hvm_suspend, &cancelled, cpumask_of(0)); | |
144 | else | |
145 | err = stop_machine(xen_suspend, &cancelled, cpumask_of(0)); | |
922cc38a JF |
146 | |
147 | dpm_resume_noirq(PMSG_RESUME); | |
148 | ||
0e91398f JF |
149 | if (err) { |
150 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); | |
65f63384 | 151 | cancelled = 1; |
0e91398f JF |
152 | } |
153 | ||
c5cae661 | 154 | out_resume: |
ad55db9f IY |
155 | if (!cancelled) { |
156 | xen_arch_resume(); | |
de5b31bd | 157 | xs_resume(); |
ad55db9f | 158 | } else |
de5b31bd | 159 | xs_suspend_cancel(); |
0e91398f | 160 | |
d1616302 | 161 | dpm_resume_end(PMSG_RESUME); |
0e91398f | 162 | |
359cdd3f JF |
163 | /* Make sure timer events get retriggered on all CPUs */ |
164 | clock_was_set(); | |
65f63384 IC |
165 | |
166 | out_thaw: | |
0e91398f JF |
167 | #ifdef CONFIG_PREEMPT |
168 | thaw_processes(); | |
65f63384 | 169 | out: |
3fc1f1e2 | 170 | #endif |
0e91398f JF |
171 | shutting_down = SHUTDOWN_INVALID; |
172 | } | |
c7827728 | 173 | #endif /* CONFIG_PM_SLEEP */ |
3e2b8fbe JF |
174 | |
175 | static void shutdown_handler(struct xenbus_watch *watch, | |
176 | const char **vec, unsigned int len) | |
177 | { | |
178 | char *str; | |
179 | struct xenbus_transaction xbt; | |
180 | int err; | |
181 | ||
182 | if (shutting_down != SHUTDOWN_INVALID) | |
183 | return; | |
184 | ||
185 | again: | |
186 | err = xenbus_transaction_start(&xbt); | |
187 | if (err) | |
188 | return; | |
189 | ||
190 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
191 | /* Ignore read errors and empty reads. */ | |
192 | if (XENBUS_IS_ERR_READ(str)) { | |
193 | xenbus_transaction_end(xbt, 1); | |
194 | return; | |
195 | } | |
196 | ||
197 | xenbus_write(xbt, "control", "shutdown", ""); | |
198 | ||
199 | err = xenbus_transaction_end(xbt, 0); | |
200 | if (err == -EAGAIN) { | |
201 | kfree(str); | |
202 | goto again; | |
203 | } | |
204 | ||
205 | if (strcmp(str, "poweroff") == 0 || | |
0e91398f JF |
206 | strcmp(str, "halt") == 0) { |
207 | shutting_down = SHUTDOWN_POWEROFF; | |
3e2b8fbe | 208 | orderly_poweroff(false); |
0e91398f JF |
209 | } else if (strcmp(str, "reboot") == 0) { |
210 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
3e2b8fbe | 211 | ctrl_alt_del(); |
0e91398f JF |
212 | #ifdef CONFIG_PM_SLEEP |
213 | } else if (strcmp(str, "suspend") == 0) { | |
214 | do_suspend(); | |
215 | #endif | |
216 | } else { | |
3e2b8fbe JF |
217 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
218 | shutting_down = SHUTDOWN_INVALID; | |
219 | } | |
220 | ||
221 | kfree(str); | |
222 | } | |
223 | ||
f3bc3189 | 224 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
225 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, |
226 | unsigned int len) | |
227 | { | |
228 | char sysrq_key = '\0'; | |
229 | struct xenbus_transaction xbt; | |
230 | int err; | |
231 | ||
232 | again: | |
233 | err = xenbus_transaction_start(&xbt); | |
234 | if (err) | |
235 | return; | |
236 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
237 | printk(KERN_ERR "Unable to read sysrq code in " | |
238 | "control/sysrq\n"); | |
239 | xenbus_transaction_end(xbt, 1); | |
240 | return; | |
241 | } | |
242 | ||
243 | if (sysrq_key != '\0') | |
244 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
245 | ||
246 | err = xenbus_transaction_end(xbt, 0); | |
247 | if (err == -EAGAIN) | |
248 | goto again; | |
249 | ||
250 | if (sysrq_key != '\0') | |
f335397d | 251 | handle_sysrq(sysrq_key); |
3e2b8fbe JF |
252 | } |
253 | ||
3e2b8fbe JF |
254 | static struct xenbus_watch sysrq_watch = { |
255 | .node = "control/sysrq", | |
256 | .callback = sysrq_handler | |
257 | }; | |
f3bc3189 RD |
258 | #endif |
259 | ||
260 | static struct xenbus_watch shutdown_watch = { | |
261 | .node = "control/shutdown", | |
262 | .callback = shutdown_handler | |
263 | }; | |
3e2b8fbe JF |
264 | |
265 | static int setup_shutdown_watcher(void) | |
266 | { | |
267 | int err; | |
268 | ||
269 | err = register_xenbus_watch(&shutdown_watch); | |
270 | if (err) { | |
271 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
272 | return err; | |
273 | } | |
274 | ||
f3bc3189 | 275 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
276 | err = register_xenbus_watch(&sysrq_watch); |
277 | if (err) { | |
278 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
279 | return err; | |
280 | } | |
f3bc3189 | 281 | #endif |
3e2b8fbe JF |
282 | |
283 | return 0; | |
284 | } | |
285 | ||
286 | static int shutdown_event(struct notifier_block *notifier, | |
287 | unsigned long event, | |
288 | void *data) | |
289 | { | |
290 | setup_shutdown_watcher(); | |
291 | return NOTIFY_DONE; | |
292 | } | |
293 | ||
016b6f5f | 294 | int xen_setup_shutdown_event(void) |
3e2b8fbe JF |
295 | { |
296 | static struct notifier_block xenstore_notifier = { | |
297 | .notifier_call = shutdown_event | |
298 | }; | |
702d4eb9 SS |
299 | |
300 | if (!xen_domain()) | |
301 | return -ENODEV; | |
3e2b8fbe JF |
302 | register_xenstore_notifier(&xenstore_notifier); |
303 | ||
304 | return 0; | |
305 | } | |
183d03cc | 306 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 307 | |
702d4eb9 | 308 | subsys_initcall(xen_setup_shutdown_event); |