Jeremy Fitzhardinge | 3e2b8fb | 2007-07-17 18:37:07 -0700 | [diff] [blame] | 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> |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 8 | #include <linux/stop_machine.h> |
| 9 | #include <linux/freezer.h> |
Jeremy Fitzhardinge | 3e2b8fb | 2007-07-17 18:37:07 -0700 | [diff] [blame] | 10 | |
| 11 | #include <xen/xenbus.h> |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 12 | #include <xen/grant_table.h> |
| 13 | #include <xen/events.h> |
| 14 | #include <xen/hvc-console.h> |
| 15 | #include <xen/xen-ops.h> |
Jeremy Fitzhardinge | 3e2b8fb | 2007-07-17 18:37:07 -0700 | [diff] [blame] | 16 | |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 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 | }; |
Jeremy Fitzhardinge | 3e2b8fb | 2007-07-17 18:37:07 -0700 | [diff] [blame] | 30 | |
| 31 | /* Ignore multiple shutdown requests. */ |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 32 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
| 33 | |
Jeremy Fitzhardinge | c782772 | 2008-05-29 09:02:19 +0100 | [diff] [blame] | 34 | #ifdef CONFIG_PM_SLEEP |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 35 | static int xen_suspend(void *data) |
| 36 | { |
| 37 | int *cancelled = data; |
Jeremy Fitzhardinge | 359cdd3 | 2008-05-26 23:31:28 +0100 | [diff] [blame] | 38 | int err; |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 39 | |
| 40 | BUG_ON(!irqs_disabled()); |
| 41 | |
Jeremy Fitzhardinge | 359cdd3 | 2008-05-26 23:31:28 +0100 | [diff] [blame] | 42 | err = device_power_down(PMSG_SUSPEND); |
| 43 | if (err) { |
| 44 | printk(KERN_ERR "xen_suspend: device_power_down failed: %d\n", |
| 45 | err); |
| 46 | return err; |
| 47 | } |
| 48 | |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 49 | xen_mm_pin_all(); |
| 50 | gnttab_suspend(); |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 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); |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 61 | gnttab_resume(); |
| 62 | xen_mm_unpin_all(); |
| 63 | |
Stephen Rothwell | 55ca089 | 2008-07-17 13:09:24 +1000 | [diff] [blame] | 64 | device_power_up(PMSG_RESUME); |
Jeremy Fitzhardinge | 359cdd3 | 2008-05-26 23:31:28 +0100 | [diff] [blame] | 65 | |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 66 | if (!*cancelled) { |
| 67 | xen_irq_resume(); |
| 68 | xen_console_resume(); |
Isaku Yamahata | ad55db9 | 2008-07-08 15:06:32 -0700 | [diff] [blame] | 69 | xen_timer_resume(); |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 70 | } |
| 71 | |
| 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 | |
| 82 | #ifdef CONFIG_PREEMPT |
| 83 | /* If the kernel is preemptible, we need to freeze all the processes |
| 84 | to prevent them from being in the middle of a pagetable update |
| 85 | during suspend. */ |
| 86 | err = freeze_processes(); |
| 87 | if (err) { |
| 88 | printk(KERN_ERR "xen suspend: freeze failed %d\n", err); |
| 89 | return; |
| 90 | } |
| 91 | #endif |
| 92 | |
| 93 | err = device_suspend(PMSG_SUSPEND); |
| 94 | if (err) { |
| 95 | printk(KERN_ERR "xen suspend: device_suspend %d\n", err); |
| 96 | goto out; |
| 97 | } |
| 98 | |
| 99 | printk("suspending xenbus...\n"); |
| 100 | /* XXX use normal device tree? */ |
| 101 | xenbus_suspend(); |
| 102 | |
Rusty Russell | 37a7c0f | 2008-08-26 00:19:26 -0500 | [diff] [blame] | 103 | err = stop_machine(xen_suspend, &cancelled, &cpumask_of_cpu(0)); |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 104 | if (err) { |
| 105 | printk(KERN_ERR "failed to start xen_suspend: %d\n", err); |
| 106 | goto out; |
| 107 | } |
| 108 | |
Isaku Yamahata | ad55db9 | 2008-07-08 15:06:32 -0700 | [diff] [blame] | 109 | if (!cancelled) { |
| 110 | xen_arch_resume(); |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 111 | xenbus_resume(); |
Isaku Yamahata | ad55db9 | 2008-07-08 15:06:32 -0700 | [diff] [blame] | 112 | } else |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 113 | xenbus_suspend_cancel(); |
| 114 | |
Stephen Rothwell | 55ca089 | 2008-07-17 13:09:24 +1000 | [diff] [blame] | 115 | device_resume(PMSG_RESUME); |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 116 | |
Jeremy Fitzhardinge | 359cdd3 | 2008-05-26 23:31:28 +0100 | [diff] [blame] | 117 | /* Make sure timer events get retriggered on all CPUs */ |
| 118 | clock_was_set(); |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 119 | out: |
| 120 | #ifdef CONFIG_PREEMPT |
| 121 | thaw_processes(); |
| 122 | #endif |
| 123 | shutting_down = SHUTDOWN_INVALID; |
| 124 | } |
Jeremy Fitzhardinge | c782772 | 2008-05-29 09:02:19 +0100 | [diff] [blame] | 125 | #endif /* CONFIG_PM_SLEEP */ |
Jeremy Fitzhardinge | 3e2b8fb | 2007-07-17 18:37:07 -0700 | [diff] [blame] | 126 | |
| 127 | static void shutdown_handler(struct xenbus_watch *watch, |
| 128 | const char **vec, unsigned int len) |
| 129 | { |
| 130 | char *str; |
| 131 | struct xenbus_transaction xbt; |
| 132 | int err; |
| 133 | |
| 134 | if (shutting_down != SHUTDOWN_INVALID) |
| 135 | return; |
| 136 | |
| 137 | again: |
| 138 | err = xenbus_transaction_start(&xbt); |
| 139 | if (err) |
| 140 | return; |
| 141 | |
| 142 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); |
| 143 | /* Ignore read errors and empty reads. */ |
| 144 | if (XENBUS_IS_ERR_READ(str)) { |
| 145 | xenbus_transaction_end(xbt, 1); |
| 146 | return; |
| 147 | } |
| 148 | |
| 149 | xenbus_write(xbt, "control", "shutdown", ""); |
| 150 | |
| 151 | err = xenbus_transaction_end(xbt, 0); |
| 152 | if (err == -EAGAIN) { |
| 153 | kfree(str); |
| 154 | goto again; |
| 155 | } |
| 156 | |
| 157 | if (strcmp(str, "poweroff") == 0 || |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 158 | strcmp(str, "halt") == 0) { |
| 159 | shutting_down = SHUTDOWN_POWEROFF; |
Jeremy Fitzhardinge | 3e2b8fb | 2007-07-17 18:37:07 -0700 | [diff] [blame] | 160 | orderly_poweroff(false); |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 161 | } else if (strcmp(str, "reboot") == 0) { |
| 162 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ |
Jeremy Fitzhardinge | 3e2b8fb | 2007-07-17 18:37:07 -0700 | [diff] [blame] | 163 | ctrl_alt_del(); |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 164 | #ifdef CONFIG_PM_SLEEP |
| 165 | } else if (strcmp(str, "suspend") == 0) { |
| 166 | do_suspend(); |
| 167 | #endif |
| 168 | } else { |
Jeremy Fitzhardinge | 3e2b8fb | 2007-07-17 18:37:07 -0700 | [diff] [blame] | 169 | printk(KERN_INFO "Ignoring shutdown request: %s\n", str); |
| 170 | shutting_down = SHUTDOWN_INVALID; |
| 171 | } |
| 172 | |
| 173 | kfree(str); |
| 174 | } |
| 175 | |
| 176 | static void sysrq_handler(struct xenbus_watch *watch, const char **vec, |
| 177 | unsigned int len) |
| 178 | { |
| 179 | char sysrq_key = '\0'; |
| 180 | struct xenbus_transaction xbt; |
| 181 | int err; |
| 182 | |
| 183 | again: |
| 184 | err = xenbus_transaction_start(&xbt); |
| 185 | if (err) |
| 186 | return; |
| 187 | if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { |
| 188 | printk(KERN_ERR "Unable to read sysrq code in " |
| 189 | "control/sysrq\n"); |
| 190 | xenbus_transaction_end(xbt, 1); |
| 191 | return; |
| 192 | } |
| 193 | |
| 194 | if (sysrq_key != '\0') |
| 195 | xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); |
| 196 | |
| 197 | err = xenbus_transaction_end(xbt, 0); |
| 198 | if (err == -EAGAIN) |
| 199 | goto again; |
| 200 | |
| 201 | if (sysrq_key != '\0') |
| 202 | handle_sysrq(sysrq_key, NULL); |
| 203 | } |
| 204 | |
| 205 | static struct xenbus_watch shutdown_watch = { |
| 206 | .node = "control/shutdown", |
| 207 | .callback = shutdown_handler |
| 208 | }; |
| 209 | |
| 210 | static struct xenbus_watch sysrq_watch = { |
| 211 | .node = "control/sysrq", |
| 212 | .callback = sysrq_handler |
| 213 | }; |
| 214 | |
| 215 | static int setup_shutdown_watcher(void) |
| 216 | { |
| 217 | int err; |
| 218 | |
| 219 | err = register_xenbus_watch(&shutdown_watch); |
| 220 | if (err) { |
| 221 | printk(KERN_ERR "Failed to set shutdown watcher\n"); |
| 222 | return err; |
| 223 | } |
| 224 | |
| 225 | err = register_xenbus_watch(&sysrq_watch); |
| 226 | if (err) { |
| 227 | printk(KERN_ERR "Failed to set sysrq watcher\n"); |
| 228 | return err; |
| 229 | } |
| 230 | |
| 231 | return 0; |
| 232 | } |
| 233 | |
| 234 | static int shutdown_event(struct notifier_block *notifier, |
| 235 | unsigned long event, |
| 236 | void *data) |
| 237 | { |
| 238 | setup_shutdown_watcher(); |
| 239 | return NOTIFY_DONE; |
| 240 | } |
| 241 | |
| 242 | static int __init setup_shutdown_event(void) |
| 243 | { |
| 244 | static struct notifier_block xenstore_notifier = { |
| 245 | .notifier_call = shutdown_event |
| 246 | }; |
| 247 | register_xenstore_notifier(&xenstore_notifier); |
| 248 | |
| 249 | return 0; |
| 250 | } |
| 251 | |
| 252 | subsys_initcall(setup_shutdown_event); |