diff options
Diffstat (limited to 'drivers/xen/manage.c')
| -rw-r--r-- | drivers/xen/manage.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c new file mode 100644 index 00000000000..a5bc91ae6ff --- /dev/null +++ b/drivers/xen/manage.c @@ -0,0 +1,254 @@ +/* + * 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(PMSG_RESUME); + + if (!*cancelled) { + xen_irq_resume(); + xen_console_resume(); + xen_timer_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) { + xen_arch_resume(); + xenbus_resume(); + } else + xenbus_suspend_cancel(); + + device_resume(PMSG_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); |