Commit | Line | Data |
---|---|---|
3e2b8fbe JF |
1 | /* |
2 | * Handle extern requests for shutdown, reboot and sysrq | |
3 | */ | |
4 | #include <linux/kernel.h> | |
5 | #include <linux/err.h> | |
6 | #include <linux/reboot.h> | |
7 | #include <linux/sysrq.h> | |
0e91398f JF |
8 | #include <linux/stop_machine.h> |
9 | #include <linux/freezer.h> | |
3e2b8fbe JF |
10 | |
11 | #include <xen/xenbus.h> | |
0e91398f JF |
12 | #include <xen/grant_table.h> |
13 | #include <xen/events.h> | |
14 | #include <xen/hvc-console.h> | |
15 | #include <xen/xen-ops.h> | |
3e2b8fbe | 16 | |
0e91398f JF |
17 | #include <asm/xen/hypercall.h> |
18 | #include <asm/xen/page.h> | |
19 | ||
20 | enum shutdown_state { | |
21 | SHUTDOWN_INVALID = -1, | |
22 | SHUTDOWN_POWEROFF = 0, | |
23 | SHUTDOWN_SUSPEND = 2, | |
24 | /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only | |
25 | report a crash, not be instructed to crash! | |
26 | HALT is the same as POWEROFF, as far as we're concerned. The tools use | |
27 | the distinction when we return the reason code to them. */ | |
28 | SHUTDOWN_HALT = 4, | |
29 | }; | |
3e2b8fbe JF |
30 | |
31 | /* Ignore multiple shutdown requests. */ | |
0e91398f JF |
32 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
33 | ||
c7827728 | 34 | #ifdef CONFIG_PM_SLEEP |
0e91398f JF |
35 | static int xen_suspend(void *data) |
36 | { | |
37 | int *cancelled = data; | |
359cdd3f | 38 | int err; |
0e91398f JF |
39 | |
40 | BUG_ON(!irqs_disabled()); | |
41 | ||
770824bd RW |
42 | err = sysdev_suspend(PMSG_SUSPEND); |
43 | if (err) { | |
44 | printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n", | |
45 | err); | |
770824bd RW |
46 | return err; |
47 | } | |
359cdd3f | 48 | |
0e91398f JF |
49 | xen_mm_pin_all(); |
50 | gnttab_suspend(); | |
0e91398f JF |
51 | xen_pre_suspend(); |
52 | ||
53 | /* | |
54 | * This hypercall returns 1 if suspend was cancelled | |
55 | * or the domain was merely checkpointed, and 0 if it | |
56 | * is resuming in a new domain. | |
57 | */ | |
58 | *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); | |
59 | ||
60 | xen_post_suspend(*cancelled); | |
0e91398f JF |
61 | gnttab_resume(); |
62 | xen_mm_unpin_all(); | |
63 | ||
64 | if (!*cancelled) { | |
65 | xen_irq_resume(); | |
66 | xen_console_resume(); | |
ad55db9f | 67 | xen_timer_resume(); |
0e91398f JF |
68 | } |
69 | ||
1e6fcf84 | 70 | sysdev_resume(); |
1e6fcf84 | 71 | |
0e91398f JF |
72 | return 0; |
73 | } | |
74 | ||
75 | static void do_suspend(void) | |
76 | { | |
77 | int err; | |
78 | int cancelled = 1; | |
79 | ||
80 | shutting_down = SHUTDOWN_SUSPEND; | |
81 | ||
b4606f21 IC |
82 | err = stop_machine_create(); |
83 | if (err) { | |
84 | printk(KERN_ERR "xen suspend: failed to setup stop_machine %d\n", err); | |
85 | goto out; | |
86 | } | |
87 | ||
0e91398f JF |
88 | #ifdef CONFIG_PREEMPT |
89 | /* If the kernel is preemptible, we need to freeze all the processes | |
90 | to prevent them from being in the middle of a pagetable update | |
91 | during suspend. */ | |
92 | err = freeze_processes(); | |
93 | if (err) { | |
94 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
b4606f21 | 95 | goto out_destroy_sm; |
0e91398f JF |
96 | } |
97 | #endif | |
98 | ||
d1616302 | 99 | err = dpm_suspend_start(PMSG_SUSPEND); |
0e91398f | 100 | if (err) { |
d1616302 | 101 | printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); |
65f63384 | 102 | goto out_thaw; |
0e91398f JF |
103 | } |
104 | ||
c5cae661 IC |
105 | printk(KERN_DEBUG "suspending xenstore...\n"); |
106 | xs_suspend(); | |
107 | ||
d1616302 | 108 | err = dpm_suspend_noirq(PMSG_SUSPEND); |
2ed8d2b3 | 109 | if (err) { |
d1616302 | 110 | printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err); |
65f63384 | 111 | goto out_resume; |
2ed8d2b3 RW |
112 | } |
113 | ||
f7df8ed1 | 114 | err = stop_machine(xen_suspend, &cancelled, cpumask_of(0)); |
922cc38a JF |
115 | |
116 | dpm_resume_noirq(PMSG_RESUME); | |
117 | ||
0e91398f JF |
118 | if (err) { |
119 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); | |
65f63384 | 120 | cancelled = 1; |
0e91398f JF |
121 | } |
122 | ||
c5cae661 | 123 | out_resume: |
ad55db9f IY |
124 | if (!cancelled) { |
125 | xen_arch_resume(); | |
de5b31bd | 126 | xs_resume(); |
ad55db9f | 127 | } else |
de5b31bd | 128 | xs_suspend_cancel(); |
0e91398f | 129 | |
d1616302 | 130 | dpm_resume_end(PMSG_RESUME); |
0e91398f | 131 | |
359cdd3f JF |
132 | /* Make sure timer events get retriggered on all CPUs */ |
133 | clock_was_set(); | |
65f63384 IC |
134 | |
135 | out_thaw: | |
0e91398f JF |
136 | #ifdef CONFIG_PREEMPT |
137 | thaw_processes(); | |
b4606f21 IC |
138 | |
139 | out_destroy_sm: | |
0e91398f | 140 | #endif |
b4606f21 IC |
141 | stop_machine_destroy(); |
142 | ||
65f63384 | 143 | out: |
0e91398f JF |
144 | shutting_down = SHUTDOWN_INVALID; |
145 | } | |
c7827728 | 146 | #endif /* CONFIG_PM_SLEEP */ |
3e2b8fbe JF |
147 | |
148 | static void shutdown_handler(struct xenbus_watch *watch, | |
149 | const char **vec, unsigned int len) | |
150 | { | |
151 | char *str; | |
152 | struct xenbus_transaction xbt; | |
153 | int err; | |
154 | ||
155 | if (shutting_down != SHUTDOWN_INVALID) | |
156 | return; | |
157 | ||
158 | again: | |
159 | err = xenbus_transaction_start(&xbt); | |
160 | if (err) | |
161 | return; | |
162 | ||
163 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
164 | /* Ignore read errors and empty reads. */ | |
165 | if (XENBUS_IS_ERR_READ(str)) { | |
166 | xenbus_transaction_end(xbt, 1); | |
167 | return; | |
168 | } | |
169 | ||
170 | xenbus_write(xbt, "control", "shutdown", ""); | |
171 | ||
172 | err = xenbus_transaction_end(xbt, 0); | |
173 | if (err == -EAGAIN) { | |
174 | kfree(str); | |
175 | goto again; | |
176 | } | |
177 | ||
178 | if (strcmp(str, "poweroff") == 0 || | |
0e91398f JF |
179 | strcmp(str, "halt") == 0) { |
180 | shutting_down = SHUTDOWN_POWEROFF; | |
3e2b8fbe | 181 | orderly_poweroff(false); |
0e91398f JF |
182 | } else if (strcmp(str, "reboot") == 0) { |
183 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
3e2b8fbe | 184 | ctrl_alt_del(); |
0e91398f JF |
185 | #ifdef CONFIG_PM_SLEEP |
186 | } else if (strcmp(str, "suspend") == 0) { | |
187 | do_suspend(); | |
188 | #endif | |
189 | } else { | |
3e2b8fbe JF |
190 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
191 | shutting_down = SHUTDOWN_INVALID; | |
192 | } | |
193 | ||
194 | kfree(str); | |
195 | } | |
196 | ||
197 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, | |
198 | unsigned int len) | |
199 | { | |
200 | char sysrq_key = '\0'; | |
201 | struct xenbus_transaction xbt; | |
202 | int err; | |
203 | ||
204 | again: | |
205 | err = xenbus_transaction_start(&xbt); | |
206 | if (err) | |
207 | return; | |
208 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
209 | printk(KERN_ERR "Unable to read sysrq code in " | |
210 | "control/sysrq\n"); | |
211 | xenbus_transaction_end(xbt, 1); | |
212 | return; | |
213 | } | |
214 | ||
215 | if (sysrq_key != '\0') | |
216 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
217 | ||
218 | err = xenbus_transaction_end(xbt, 0); | |
219 | if (err == -EAGAIN) | |
220 | goto again; | |
221 | ||
222 | if (sysrq_key != '\0') | |
223 | handle_sysrq(sysrq_key, NULL); | |
224 | } | |
225 | ||
226 | static struct xenbus_watch shutdown_watch = { | |
227 | .node = "control/shutdown", | |
228 | .callback = shutdown_handler | |
229 | }; | |
230 | ||
231 | static struct xenbus_watch sysrq_watch = { | |
232 | .node = "control/sysrq", | |
233 | .callback = sysrq_handler | |
234 | }; | |
235 | ||
236 | static int setup_shutdown_watcher(void) | |
237 | { | |
238 | int err; | |
239 | ||
240 | err = register_xenbus_watch(&shutdown_watch); | |
241 | if (err) { | |
242 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
243 | return err; | |
244 | } | |
245 | ||
246 | err = register_xenbus_watch(&sysrq_watch); | |
247 | if (err) { | |
248 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
249 | return err; | |
250 | } | |
251 | ||
252 | return 0; | |
253 | } | |
254 | ||
255 | static int shutdown_event(struct notifier_block *notifier, | |
256 | unsigned long event, | |
257 | void *data) | |
258 | { | |
259 | setup_shutdown_watcher(); | |
260 | return NOTIFY_DONE; | |
261 | } | |
262 | ||
263 | static int __init setup_shutdown_event(void) | |
264 | { | |
265 | static struct notifier_block xenstore_notifier = { | |
266 | .notifier_call = shutdown_event | |
267 | }; | |
268 | register_xenstore_notifier(&xenstore_notifier); | |
269 | ||
270 | return 0; | |
271 | } | |
272 | ||
273 | subsys_initcall(setup_shutdown_event); |