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> | |
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 JF |
11 | |
12 | #include <xen/xenbus.h> | |
0e91398f JF |
13 | #include <xen/grant_table.h> |
14 | #include <xen/events.h> | |
15 | #include <xen/hvc-console.h> | |
16 | #include <xen/xen-ops.h> | |
3e2b8fbe | 17 | |
0e91398f JF |
18 | #include <asm/xen/hypercall.h> |
19 | #include <asm/xen/page.h> | |
20 | ||
21 | enum shutdown_state { | |
22 | SHUTDOWN_INVALID = -1, | |
23 | SHUTDOWN_POWEROFF = 0, | |
24 | SHUTDOWN_SUSPEND = 2, | |
25 | /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only | |
26 | report a crash, not be instructed to crash! | |
27 | HALT is the same as POWEROFF, as far as we're concerned. The tools use | |
28 | the distinction when we return the reason code to them. */ | |
29 | SHUTDOWN_HALT = 4, | |
30 | }; | |
3e2b8fbe JF |
31 | |
32 | /* Ignore multiple shutdown requests. */ | |
0e91398f JF |
33 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
34 | ||
c7827728 | 35 | #ifdef CONFIG_PM_SLEEP |
0e91398f JF |
36 | static int xen_suspend(void *data) |
37 | { | |
38 | int *cancelled = data; | |
359cdd3f | 39 | int err; |
0e91398f JF |
40 | |
41 | BUG_ON(!irqs_disabled()); | |
42 | ||
770824bd RW |
43 | err = sysdev_suspend(PMSG_SUSPEND); |
44 | if (err) { | |
45 | printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n", | |
46 | err); | |
770824bd RW |
47 | return err; |
48 | } | |
359cdd3f | 49 | |
0e91398f JF |
50 | xen_mm_pin_all(); |
51 | gnttab_suspend(); | |
0e91398f JF |
52 | xen_pre_suspend(); |
53 | ||
54 | /* | |
55 | * This hypercall returns 1 if suspend was cancelled | |
56 | * or the domain was merely checkpointed, and 0 if it | |
57 | * is resuming in a new domain. | |
58 | */ | |
59 | *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); | |
60 | ||
61 | xen_post_suspend(*cancelled); | |
0e91398f JF |
62 | gnttab_resume(); |
63 | xen_mm_unpin_all(); | |
64 | ||
65 | if (!*cancelled) { | |
66 | xen_irq_resume(); | |
67 | xen_console_resume(); | |
ad55db9f | 68 | xen_timer_resume(); |
0e91398f JF |
69 | } |
70 | ||
1e6fcf84 | 71 | sysdev_resume(); |
1e6fcf84 | 72 | |
0e91398f JF |
73 | return 0; |
74 | } | |
75 | ||
76 | static void do_suspend(void) | |
77 | { | |
78 | int err; | |
79 | int cancelled = 1; | |
80 | ||
81 | shutting_down = SHUTDOWN_SUSPEND; | |
82 | ||
83 | #ifdef CONFIG_PREEMPT | |
84 | /* If the kernel is preemptible, we need to freeze all the processes | |
85 | to prevent them from being in the middle of a pagetable update | |
86 | during suspend. */ | |
87 | err = freeze_processes(); | |
88 | if (err) { | |
89 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
3fc1f1e2 | 90 | goto out; |
0e91398f JF |
91 | } |
92 | #endif | |
93 | ||
d1616302 | 94 | err = dpm_suspend_start(PMSG_SUSPEND); |
0e91398f | 95 | if (err) { |
d1616302 | 96 | printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); |
65f63384 | 97 | goto out_thaw; |
0e91398f JF |
98 | } |
99 | ||
c5cae661 IC |
100 | printk(KERN_DEBUG "suspending xenstore...\n"); |
101 | xs_suspend(); | |
102 | ||
d1616302 | 103 | err = dpm_suspend_noirq(PMSG_SUSPEND); |
2ed8d2b3 | 104 | if (err) { |
d1616302 | 105 | printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err); |
65f63384 | 106 | goto out_resume; |
2ed8d2b3 RW |
107 | } |
108 | ||
f7df8ed1 | 109 | err = stop_machine(xen_suspend, &cancelled, cpumask_of(0)); |
922cc38a JF |
110 | |
111 | dpm_resume_noirq(PMSG_RESUME); | |
112 | ||
0e91398f JF |
113 | if (err) { |
114 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); | |
65f63384 | 115 | cancelled = 1; |
0e91398f JF |
116 | } |
117 | ||
c5cae661 | 118 | out_resume: |
ad55db9f IY |
119 | if (!cancelled) { |
120 | xen_arch_resume(); | |
de5b31bd | 121 | xs_resume(); |
ad55db9f | 122 | } else |
de5b31bd | 123 | xs_suspend_cancel(); |
0e91398f | 124 | |
d1616302 | 125 | dpm_resume_end(PMSG_RESUME); |
0e91398f | 126 | |
359cdd3f JF |
127 | /* Make sure timer events get retriggered on all CPUs */ |
128 | clock_was_set(); | |
65f63384 IC |
129 | |
130 | out_thaw: | |
0e91398f JF |
131 | #ifdef CONFIG_PREEMPT |
132 | thaw_processes(); | |
65f63384 | 133 | out: |
3fc1f1e2 | 134 | #endif |
0e91398f JF |
135 | shutting_down = SHUTDOWN_INVALID; |
136 | } | |
c7827728 | 137 | #endif /* CONFIG_PM_SLEEP */ |
3e2b8fbe JF |
138 | |
139 | static void shutdown_handler(struct xenbus_watch *watch, | |
140 | const char **vec, unsigned int len) | |
141 | { | |
142 | char *str; | |
143 | struct xenbus_transaction xbt; | |
144 | int err; | |
145 | ||
146 | if (shutting_down != SHUTDOWN_INVALID) | |
147 | return; | |
148 | ||
149 | again: | |
150 | err = xenbus_transaction_start(&xbt); | |
151 | if (err) | |
152 | return; | |
153 | ||
154 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
155 | /* Ignore read errors and empty reads. */ | |
156 | if (XENBUS_IS_ERR_READ(str)) { | |
157 | xenbus_transaction_end(xbt, 1); | |
158 | return; | |
159 | } | |
160 | ||
161 | xenbus_write(xbt, "control", "shutdown", ""); | |
162 | ||
163 | err = xenbus_transaction_end(xbt, 0); | |
164 | if (err == -EAGAIN) { | |
165 | kfree(str); | |
166 | goto again; | |
167 | } | |
168 | ||
169 | if (strcmp(str, "poweroff") == 0 || | |
0e91398f JF |
170 | strcmp(str, "halt") == 0) { |
171 | shutting_down = SHUTDOWN_POWEROFF; | |
3e2b8fbe | 172 | orderly_poweroff(false); |
0e91398f JF |
173 | } else if (strcmp(str, "reboot") == 0) { |
174 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
3e2b8fbe | 175 | ctrl_alt_del(); |
0e91398f JF |
176 | #ifdef CONFIG_PM_SLEEP |
177 | } else if (strcmp(str, "suspend") == 0) { | |
178 | do_suspend(); | |
179 | #endif | |
180 | } else { | |
3e2b8fbe JF |
181 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
182 | shutting_down = SHUTDOWN_INVALID; | |
183 | } | |
184 | ||
185 | kfree(str); | |
186 | } | |
187 | ||
f3bc3189 | 188 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
189 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, |
190 | unsigned int len) | |
191 | { | |
192 | char sysrq_key = '\0'; | |
193 | struct xenbus_transaction xbt; | |
194 | int err; | |
195 | ||
196 | again: | |
197 | err = xenbus_transaction_start(&xbt); | |
198 | if (err) | |
199 | return; | |
200 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
201 | printk(KERN_ERR "Unable to read sysrq code in " | |
202 | "control/sysrq\n"); | |
203 | xenbus_transaction_end(xbt, 1); | |
204 | return; | |
205 | } | |
206 | ||
207 | if (sysrq_key != '\0') | |
208 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
209 | ||
210 | err = xenbus_transaction_end(xbt, 0); | |
211 | if (err == -EAGAIN) | |
212 | goto again; | |
213 | ||
214 | if (sysrq_key != '\0') | |
215 | handle_sysrq(sysrq_key, NULL); | |
216 | } | |
217 | ||
3e2b8fbe JF |
218 | static struct xenbus_watch sysrq_watch = { |
219 | .node = "control/sysrq", | |
220 | .callback = sysrq_handler | |
221 | }; | |
f3bc3189 RD |
222 | #endif |
223 | ||
224 | static struct xenbus_watch shutdown_watch = { | |
225 | .node = "control/shutdown", | |
226 | .callback = shutdown_handler | |
227 | }; | |
3e2b8fbe JF |
228 | |
229 | static int setup_shutdown_watcher(void) | |
230 | { | |
231 | int err; | |
232 | ||
233 | err = register_xenbus_watch(&shutdown_watch); | |
234 | if (err) { | |
235 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
236 | return err; | |
237 | } | |
238 | ||
f3bc3189 | 239 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
240 | err = register_xenbus_watch(&sysrq_watch); |
241 | if (err) { | |
242 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
243 | return err; | |
244 | } | |
f3bc3189 | 245 | #endif |
3e2b8fbe JF |
246 | |
247 | return 0; | |
248 | } | |
249 | ||
250 | static int shutdown_event(struct notifier_block *notifier, | |
251 | unsigned long event, | |
252 | void *data) | |
253 | { | |
254 | setup_shutdown_watcher(); | |
255 | return NOTIFY_DONE; | |
256 | } | |
257 | ||
258 | static int __init setup_shutdown_event(void) | |
259 | { | |
260 | static struct notifier_block xenstore_notifier = { | |
261 | .notifier_call = shutdown_event | |
262 | }; | |
263 | register_xenstore_notifier(&xenstore_notifier); | |
264 | ||
265 | return 0; | |
266 | } | |
267 | ||
268 | subsys_initcall(setup_shutdown_event); |