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-rw-r--r--drivers/xen/manage.c252
1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
new file mode 100644
index 000000000000..5b546e365f00
--- /dev/null
+++ b/drivers/xen/manage.c
@@ -0,0 +1,252 @@
+/*
+ * Handle extern requests for shutdown, reboot and sysrq
+ */
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/reboot.h>
+#include <linux/sysrq.h>
+#include <linux/stop_machine.h>
+#include <linux/freezer.h>
+
+#include <xen/xenbus.h>
+#include <xen/grant_table.h>
+#include <xen/events.h>
+#include <xen/hvc-console.h>
+#include <xen/xen-ops.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/xen/page.h>
+
+enum shutdown_state {
+ SHUTDOWN_INVALID = -1,
+ SHUTDOWN_POWEROFF = 0,
+ SHUTDOWN_SUSPEND = 2,
+ /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only
+ report a crash, not be instructed to crash!
+ HALT is the same as POWEROFF, as far as we're concerned. The tools use
+ the distinction when we return the reason code to them. */
+ SHUTDOWN_HALT = 4,
+};
+
+/* Ignore multiple shutdown requests. */
+static enum shutdown_state shutting_down = SHUTDOWN_INVALID;
+
+#ifdef CONFIG_PM_SLEEP
+static int xen_suspend(void *data)
+{
+ int *cancelled = data;
+ int err;
+
+ BUG_ON(!irqs_disabled());
+
+ load_cr3(swapper_pg_dir);
+
+ err = device_power_down(PMSG_SUSPEND);
+ if (err) {
+ printk(KERN_ERR "xen_suspend: device_power_down failed: %d\n",
+ err);
+ return err;
+ }
+
+ xen_mm_pin_all();
+ gnttab_suspend();
+ xen_pre_suspend();
+
+ /*
+ * This hypercall returns 1 if suspend was cancelled
+ * or the domain was merely checkpointed, and 0 if it
+ * is resuming in a new domain.
+ */
+ *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info));
+
+ xen_post_suspend(*cancelled);
+ gnttab_resume();
+ xen_mm_unpin_all();
+
+ device_power_up();
+
+ if (!*cancelled) {
+ xen_irq_resume();
+ xen_console_resume();
+ }
+
+ return 0;
+}
+
+static void do_suspend(void)
+{
+ int err;
+ int cancelled = 1;
+
+ shutting_down = SHUTDOWN_SUSPEND;
+
+#ifdef CONFIG_PREEMPT
+ /* If the kernel is preemptible, we need to freeze all the processes
+ to prevent them from being in the middle of a pagetable update
+ during suspend. */
+ err = freeze_processes();
+ if (err) {
+ printk(KERN_ERR "xen suspend: freeze failed %d\n", err);
+ return;
+ }
+#endif
+
+ err = device_suspend(PMSG_SUSPEND);
+ if (err) {
+ printk(KERN_ERR "xen suspend: device_suspend %d\n", err);
+ goto out;
+ }
+
+ printk("suspending xenbus...\n");
+ /* XXX use normal device tree? */
+ xenbus_suspend();
+
+ err = stop_machine_run(xen_suspend, &cancelled, 0);
+ if (err) {
+ printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
+ goto out;
+ }
+
+ if (!cancelled)
+ xenbus_resume();
+ else
+ xenbus_suspend_cancel();
+
+ device_resume();
+
+ /* Make sure timer events get retriggered on all CPUs */
+ clock_was_set();
+out:
+#ifdef CONFIG_PREEMPT
+ thaw_processes();
+#endif
+ shutting_down = SHUTDOWN_INVALID;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static void shutdown_handler(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ char *str;
+ struct xenbus_transaction xbt;
+ int err;
+
+ if (shutting_down != SHUTDOWN_INVALID)
+ return;
+
+ again:
+ err = xenbus_transaction_start(&xbt);
+ if (err)
+ return;
+
+ str = (char *)xenbus_read(xbt, "control", "shutdown", NULL);
+ /* Ignore read errors and empty reads. */
+ if (XENBUS_IS_ERR_READ(str)) {
+ xenbus_transaction_end(xbt, 1);
+ return;
+ }
+
+ xenbus_write(xbt, "control", "shutdown", "");
+
+ err = xenbus_transaction_end(xbt, 0);
+ if (err == -EAGAIN) {
+ kfree(str);
+ goto again;
+ }
+
+ if (strcmp(str, "poweroff") == 0 ||
+ strcmp(str, "halt") == 0) {
+ shutting_down = SHUTDOWN_POWEROFF;
+ orderly_poweroff(false);
+ } else if (strcmp(str, "reboot") == 0) {
+ shutting_down = SHUTDOWN_POWEROFF; /* ? */
+ ctrl_alt_del();
+#ifdef CONFIG_PM_SLEEP
+ } else if (strcmp(str, "suspend") == 0) {
+ do_suspend();
+#endif
+ } else {
+ printk(KERN_INFO "Ignoring shutdown request: %s\n", str);
+ shutting_down = SHUTDOWN_INVALID;
+ }
+
+ kfree(str);
+}
+
+static void sysrq_handler(struct xenbus_watch *watch, const char **vec,
+ unsigned int len)
+{
+ char sysrq_key = '\0';
+ struct xenbus_transaction xbt;
+ int err;
+
+ again:
+ err = xenbus_transaction_start(&xbt);
+ if (err)
+ return;
+ if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) {
+ printk(KERN_ERR "Unable to read sysrq code in "
+ "control/sysrq\n");
+ xenbus_transaction_end(xbt, 1);
+ return;
+ }
+
+ if (sysrq_key != '\0')
+ xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
+
+ err = xenbus_transaction_end(xbt, 0);
+ if (err == -EAGAIN)
+ goto again;
+
+ if (sysrq_key != '\0')
+ handle_sysrq(sysrq_key, NULL);
+}
+
+static struct xenbus_watch shutdown_watch = {
+ .node = "control/shutdown",
+ .callback = shutdown_handler
+};
+
+static struct xenbus_watch sysrq_watch = {
+ .node = "control/sysrq",
+ .callback = sysrq_handler
+};
+
+static int setup_shutdown_watcher(void)
+{
+ int err;
+
+ err = register_xenbus_watch(&shutdown_watch);
+ if (err) {
+ printk(KERN_ERR "Failed to set shutdown watcher\n");
+ return err;
+ }
+
+ err = register_xenbus_watch(&sysrq_watch);
+ if (err) {
+ printk(KERN_ERR "Failed to set sysrq watcher\n");
+ return err;
+ }
+
+ return 0;
+}
+
+static int shutdown_event(struct notifier_block *notifier,
+ unsigned long event,
+ void *data)
+{
+ setup_shutdown_watcher();
+ return NOTIFY_DONE;
+}
+
+static int __init setup_shutdown_event(void)
+{
+ static struct notifier_block xenstore_notifier = {
+ .notifier_call = shutdown_event
+ };
+ register_xenstore_notifier(&xenstore_notifier);
+
+ return 0;
+}
+
+subsys_initcall(setup_shutdown_event);