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);