xen: use freeze/restore/thaw PM events for suspend/resume/chkpt

Use PM_FREEZE, PM_THAW and PM_RESTORE power events for
suspend/resume/checkpoint functionality, instead of PM_SUSPEND
and PM_RESUME. Use of these pm events fixes the Xen Guest hangup
when taking checkpoints. When a suspend event is cancelled
(while taking checkpoints once/continuously), we use PM_THAW
instead of PM_RESUME. PM_RESTORE is used when suspend is not
cancelled. See Documentation/power/devices.txt and linux/pm.h
for more info about freeze, thaw and restore. The sequence of
pm events in a suspend-resume scenario is shown below.

dpm_suspend_start(PMSG_FREEZE);

dpm_suspend_noirq(PMSG_FREEZE);

sysdev_suspend(PMSG_FREEZE);
cancelled = suspend_hypercall()
sysdev_resume();

dpm_resume_noirq(cancelled ? PMSG_THAW : PMSG_RESTORE);

dpm_resume_end(cancelled ? PMSG_THAW : PMSG_RESTORE);

Acked-by: Ian Campbell <[e-mail]>
Signed-off-by: Shriram Rajagopalan <[e-mail]>
Signed-off-by: Konrad Rzeszutek Wilk <[e-mail]>

drivers/xen/manage.c

···
 	xen_mm_unpin_all();
 }
 
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_HIBERNATION
 static int xen_suspend(void *data)
 {
 	struct suspend_info *si = data;
···
 
 	BUG_ON(!irqs_disabled());
 
-	err = sysdev_suspend(PMSG_SUSPEND);
+	err = sysdev_suspend(PMSG_FREEZE);
 	if (err) {
 		printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n",
 			err);
···
 	}
 #endif
 
-	err = dpm_suspend_start(PMSG_SUSPEND);
+	err = dpm_suspend_start(PMSG_FREEZE);
 	if (err) {
 		printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err);
 		goto out_thaw;
···
 	printk(KERN_DEBUG "suspending xenstore...\n");
 	xs_suspend();
 
-	err = dpm_suspend_noirq(PMSG_SUSPEND);
+	err = dpm_suspend_noirq(PMSG_FREEZE);
 	if (err) {
 		printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err);
 		goto out_resume;
···
 
 	err = stop_machine(xen_suspend, &si, cpumask_of(0));
 
-	dpm_resume_noirq(PMSG_RESUME);
+	dpm_resume_noirq(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
 
 	if (err) {
 		printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
···
 	} else
 		xs_suspend_cancel();
 
-	dpm_resume_end(PMSG_RESUME);
+	dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
 
 	/* Make sure timer events get retriggered on all CPUs */
 	clock_was_set();
···
 #endif
 	shutting_down = SHUTDOWN_INVALID;
 }
-#endif	/* CONFIG_PM_SLEEP */
+#endif	/* CONFIG_HIBERNATION */
 
 struct shutdown_handler {
 	const char *command;
···
 		{ "poweroff",	do_poweroff },
 		{ "halt",	do_poweroff },
 		{ "reboot",	do_reboot   },
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_HIBERNATION
 		{ "suspend",	do_suspend  },
 #endif
 		{NULL, NULL},

drivers/xen/xenbus/xenbus_probe_frontend.c

···
 };
 
 static const struct dev_pm_ops xenbus_pm_ops = {
-	.suspend = xenbus_dev_suspend,
-	.resume  = xenbus_dev_resume,
-	.thaw  = xenbus_dev_cancel,
+	.suspend	= xenbus_dev_suspend,
+	.resume		= xenbus_dev_resume,
+	.freeze		= xenbus_dev_suspend,
+	.thaw		= xenbus_dev_cancel,
+	.restore	= xenbus_dev_resume,
 };
 
 static struct xen_bus_type xenbus_frontend = {