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 | ||
42 | load_cr3(swapper_pg_dir); | |
43 | ||
359cdd3f JF |
44 | err = device_power_down(PMSG_SUSPEND); |
45 | if (err) { | |
46 | printk(KERN_ERR "xen_suspend: device_power_down failed: %d\n", | |
47 | err); | |
48 | return err; | |
49 | } | |
50 | ||
0e91398f JF |
51 | xen_mm_pin_all(); |
52 | gnttab_suspend(); | |
0e91398f JF |
53 | xen_pre_suspend(); |
54 | ||
55 | /* | |
56 | * This hypercall returns 1 if suspend was cancelled | |
57 | * or the domain was merely checkpointed, and 0 if it | |
58 | * is resuming in a new domain. | |
59 | */ | |
60 | *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); | |
61 | ||
62 | xen_post_suspend(*cancelled); | |
0e91398f JF |
63 | gnttab_resume(); |
64 | xen_mm_unpin_all(); | |
65 | ||
55ca089e | 66 | device_power_up(PMSG_RESUME); |
359cdd3f | 67 | |
0e91398f JF |
68 | if (!*cancelled) { |
69 | xen_irq_resume(); | |
70 | xen_console_resume(); | |
ad55db9f | 71 | xen_timer_resume(); |
0e91398f JF |
72 | } |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
77 | static void do_suspend(void) | |
78 | { | |
79 | int err; | |
80 | int cancelled = 1; | |
81 | ||
82 | shutting_down = SHUTDOWN_SUSPEND; | |
83 | ||
84 | #ifdef CONFIG_PREEMPT | |
85 | /* If the kernel is preemptible, we need to freeze all the processes | |
86 | to prevent them from being in the middle of a pagetable update | |
87 | during suspend. */ | |
88 | err = freeze_processes(); | |
89 | if (err) { | |
90 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); | |
91 | return; | |
92 | } | |
93 | #endif | |
94 | ||
95 | err = device_suspend(PMSG_SUSPEND); | |
96 | if (err) { | |
97 | printk(KERN_ERR "xen suspend: device_suspend %d\n", err); | |
98 | goto out; | |
99 | } | |
100 | ||
101 | printk("suspending xenbus...\n"); | |
102 | /* XXX use normal device tree? */ | |
103 | xenbus_suspend(); | |
104 | ||
105 | err = stop_machine_run(xen_suspend, &cancelled, 0); | |
106 | if (err) { | |
107 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); | |
108 | goto out; | |
109 | } | |
110 | ||
ad55db9f IY |
111 | if (!cancelled) { |
112 | xen_arch_resume(); | |
0e91398f | 113 | xenbus_resume(); |
ad55db9f | 114 | } else |
0e91398f JF |
115 | xenbus_suspend_cancel(); |
116 | ||
55ca089e | 117 | device_resume(PMSG_RESUME); |
0e91398f | 118 | |
359cdd3f JF |
119 | /* Make sure timer events get retriggered on all CPUs */ |
120 | clock_was_set(); | |
0e91398f JF |
121 | out: |
122 | #ifdef CONFIG_PREEMPT | |
123 | thaw_processes(); | |
124 | #endif | |
125 | shutting_down = SHUTDOWN_INVALID; | |
126 | } | |
c7827728 | 127 | #endif /* CONFIG_PM_SLEEP */ |
3e2b8fbe JF |
128 | |
129 | static void shutdown_handler(struct xenbus_watch *watch, | |
130 | const char **vec, unsigned int len) | |
131 | { | |
132 | char *str; | |
133 | struct xenbus_transaction xbt; | |
134 | int err; | |
135 | ||
136 | if (shutting_down != SHUTDOWN_INVALID) | |
137 | return; | |
138 | ||
139 | again: | |
140 | err = xenbus_transaction_start(&xbt); | |
141 | if (err) | |
142 | return; | |
143 | ||
144 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
145 | /* Ignore read errors and empty reads. */ | |
146 | if (XENBUS_IS_ERR_READ(str)) { | |
147 | xenbus_transaction_end(xbt, 1); | |
148 | return; | |
149 | } | |
150 | ||
151 | xenbus_write(xbt, "control", "shutdown", ""); | |
152 | ||
153 | err = xenbus_transaction_end(xbt, 0); | |
154 | if (err == -EAGAIN) { | |
155 | kfree(str); | |
156 | goto again; | |
157 | } | |
158 | ||
159 | if (strcmp(str, "poweroff") == 0 || | |
0e91398f JF |
160 | strcmp(str, "halt") == 0) { |
161 | shutting_down = SHUTDOWN_POWEROFF; | |
3e2b8fbe | 162 | orderly_poweroff(false); |
0e91398f JF |
163 | } else if (strcmp(str, "reboot") == 0) { |
164 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
3e2b8fbe | 165 | ctrl_alt_del(); |
0e91398f JF |
166 | #ifdef CONFIG_PM_SLEEP |
167 | } else if (strcmp(str, "suspend") == 0) { | |
168 | do_suspend(); | |
169 | #endif | |
170 | } else { | |
3e2b8fbe JF |
171 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
172 | shutting_down = SHUTDOWN_INVALID; | |
173 | } | |
174 | ||
175 | kfree(str); | |
176 | } | |
177 | ||
178 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, | |
179 | unsigned int len) | |
180 | { | |
181 | char sysrq_key = '\0'; | |
182 | struct xenbus_transaction xbt; | |
183 | int err; | |
184 | ||
185 | again: | |
186 | err = xenbus_transaction_start(&xbt); | |
187 | if (err) | |
188 | return; | |
189 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { | |
190 | printk(KERN_ERR "Unable to read sysrq code in " | |
191 | "control/sysrq\n"); | |
192 | xenbus_transaction_end(xbt, 1); | |
193 | return; | |
194 | } | |
195 | ||
196 | if (sysrq_key != '\0') | |
197 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
198 | ||
199 | err = xenbus_transaction_end(xbt, 0); | |
200 | if (err == -EAGAIN) | |
201 | goto again; | |
202 | ||
203 | if (sysrq_key != '\0') | |
204 | handle_sysrq(sysrq_key, NULL); | |
205 | } | |
206 | ||
207 | static struct xenbus_watch shutdown_watch = { | |
208 | .node = "control/shutdown", | |
209 | .callback = shutdown_handler | |
210 | }; | |
211 | ||
212 | static struct xenbus_watch sysrq_watch = { | |
213 | .node = "control/sysrq", | |
214 | .callback = sysrq_handler | |
215 | }; | |
216 | ||
217 | static int setup_shutdown_watcher(void) | |
218 | { | |
219 | int err; | |
220 | ||
221 | err = register_xenbus_watch(&shutdown_watch); | |
222 | if (err) { | |
223 | printk(KERN_ERR "Failed to set shutdown watcher\n"); | |
224 | return err; | |
225 | } | |
226 | ||
227 | err = register_xenbus_watch(&sysrq_watch); | |
228 | if (err) { | |
229 | printk(KERN_ERR "Failed to set sysrq watcher\n"); | |
230 | return err; | |
231 | } | |
232 | ||
233 | return 0; | |
234 | } | |
235 | ||
236 | static int shutdown_event(struct notifier_block *notifier, | |
237 | unsigned long event, | |
238 | void *data) | |
239 | { | |
240 | setup_shutdown_watcher(); | |
241 | return NOTIFY_DONE; | |
242 | } | |
243 | ||
244 | static int __init setup_shutdown_event(void) | |
245 | { | |
246 | static struct notifier_block xenstore_notifier = { | |
247 | .notifier_call = shutdown_event | |
248 | }; | |
249 | register_xenstore_notifier(&xenstore_notifier); | |
250 | ||
251 | return 0; | |
252 | } | |
253 | ||
254 | subsys_initcall(setup_shutdown_event); |