--- zzzz-none-000/linux-3.10.107/drivers/xen/xenbus/xenbus_probe_frontend.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/xen/xenbus/xenbus_probe_frontend.c	2021-02-04 17:41:59.000000000 +0000
@@ -1,6 +1,8 @@
-#define DPRINTK(fmt, args...)				\
-	pr_debug("xenbus_probe (%s:%d) " fmt ".\n",	\
-		 __func__, __LINE__, ##args)
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#define DPRINTK(fmt, ...)				\
+	pr_debug("(%s:%d) " fmt "\n",			\
+		 __func__, __LINE__, ##__VA_ARGS__)
 
 #include <linux/kernel.h>
 #include <linux/err.h>
@@ -36,13 +38,13 @@
 {
 	nodename = strchr(nodename, '/');
 	if (!nodename || strlen(nodename + 1) >= XEN_BUS_ID_SIZE) {
-		printk(KERN_WARNING "XENBUS: bad frontend %s\n", nodename);
+		pr_warn("bad frontend %s\n", nodename);
 		return -EINVAL;
 	}
 
 	strlcpy(bus_id, nodename + 1, XEN_BUS_ID_SIZE);
 	if (!strchr(bus_id, '/')) {
-		printk(KERN_WARNING "XENBUS: bus_id %s no slash\n", bus_id);
+		pr_warn("bus_id %s no slash\n", bus_id);
 		return -EINVAL;
 	}
 	*strchr(bus_id, '/') = '-';
@@ -113,7 +115,6 @@
 			return -EFAULT;
 		}
 
-		INIT_WORK(&xdev->work, xenbus_frontend_delayed_resume);
 		queue_work(xenbus_frontend_wq, &xdev->work);
 
 		return 0;
@@ -122,6 +123,16 @@
 	return xenbus_dev_resume(dev);
 }
 
+static int xenbus_frontend_dev_probe(struct device *dev)
+{
+	if (xen_store_domain_type == XS_LOCAL) {
+		struct xenbus_device *xdev = to_xenbus_device(dev);
+		INIT_WORK(&xdev->work, xenbus_frontend_delayed_resume);
+	}
+
+	return xenbus_dev_probe(dev);
+}
+
 static const struct dev_pm_ops xenbus_pm_ops = {
 	.suspend	= xenbus_dev_suspend,
 	.resume		= xenbus_frontend_dev_resume,
@@ -140,10 +151,10 @@
 		.name		= "xen",
 		.match		= xenbus_match,
 		.uevent		= xenbus_uevent_frontend,
-		.probe		= xenbus_dev_probe,
+		.probe		= xenbus_frontend_dev_probe,
 		.remove		= xenbus_dev_remove,
 		.shutdown	= xenbus_dev_shutdown,
-		.dev_attrs	= xenbus_dev_attrs,
+		.dev_groups	= xenbus_dev_groups,
 
 		.pm		= &xenbus_pm_ops,
 	},
@@ -234,15 +245,13 @@
 
 	if (!dev->driver) {
 		/* Information only: is this too noisy? */
-		printk(KERN_INFO "XENBUS: Device with no driver: %s\n",
-		       xendev->nodename);
+		pr_info("Device with no driver: %s\n", xendev->nodename);
 	} else if (xendev->state < XenbusStateConnected) {
 		enum xenbus_state rstate = XenbusStateUnknown;
 		if (xendev->otherend)
 			rstate = xenbus_read_driver_state(xendev->otherend);
-		printk(KERN_WARNING "XENBUS: Timeout connecting "
-		       "to device: %s (local state %d, remote state %d)\n",
-		       xendev->nodename, xendev->state, rstate);
+		pr_warn("Timeout connecting to device: %s (local state %d, remote state %d)\n",
+			xendev->nodename, xendev->state, rstate);
 	}
 
 	return 0;
@@ -256,12 +265,13 @@
 {
 	if (time_after(jiffies, start + (*seconds_waited+5)*HZ)) {
 		if (!*seconds_waited)
-			printk(KERN_WARNING "XENBUS: Waiting for "
-			       "devices to initialise: ");
+			pr_warn("Waiting for devices to initialise: ");
 		*seconds_waited += 5;
-		printk("%us...", max_delay - *seconds_waited);
-		if (*seconds_waited == max_delay)
+		pr_cont("%us...", max_delay - *seconds_waited);
+		if (*seconds_waited == max_delay) {
+			pr_cont("\n");
 			return true;
+		}
 	}
 
 	schedule_timeout_interruptible(HZ/10);
@@ -307,13 +317,15 @@
 			 print_device_status);
 }
 
-int xenbus_register_frontend(struct xenbus_driver *drv)
+int __xenbus_register_frontend(struct xenbus_driver *drv, struct module *owner,
+			       const char *mod_name)
 {
 	int ret;
 
 	drv->read_otherend_details = read_backend_details;
 
-	ret = xenbus_register_driver_common(drv, &xenbus_frontend);
+	ret = xenbus_register_driver_common(drv, &xenbus_frontend,
+					    owner, mod_name);
 	if (ret)
 		return ret;
 
@@ -322,7 +334,7 @@
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(xenbus_register_frontend);
+EXPORT_SYMBOL_GPL(__xenbus_register_frontend);
 
 static DECLARE_WAIT_QUEUE_HEAD(backend_state_wq);
 static int backend_state;
@@ -342,7 +354,7 @@
 	timeout = wait_event_interruptible_timeout(backend_state_wq,
 			backend_state == expected, 5 * HZ);
 	if (timeout <= 0)
-		printk(KERN_INFO "XENBUS: backend %s timed out.\n", be);
+		pr_info("backend %s timed out\n", be);
 }
 
 /*
@@ -365,7 +377,7 @@
 	be_watch.callback = xenbus_reset_backend_state_changed;
 	backend_state = XenbusStateUnknown;
 
-	printk(KERN_INFO "XENBUS: triggering reconnect on %s\n", be);
+	pr_info("triggering reconnect on %s\n", be);
 	register_xenbus_watch(&be_watch);
 
 	/* fall through to forward backend to state XenbusStateInitialising */
@@ -384,7 +396,7 @@
 	}
 
 	unregister_xenbus_watch(&be_watch);
-	printk(KERN_INFO "XENBUS: reconnect done on %s\n", be);
+	pr_info("reconnect done on %s\n", be);
 	kfree(be_watch.node);
 }
 
@@ -473,7 +485,11 @@
 
 	register_xenstore_notifier(&xenstore_notifier);
 
-	xenbus_frontend_wq = create_workqueue("xenbus_frontend");
+	if (xen_store_domain_type == XS_LOCAL) {
+		xenbus_frontend_wq = create_workqueue("xenbus_frontend");
+		if (!xenbus_frontend_wq)
+			pr_warn("create xenbus frontend workqueue failed, S3 resume is likely to fail\n");
+	}
 
 	return 0;
 }
@@ -482,7 +498,7 @@
 #ifndef MODULE
 static int __init boot_wait_for_devices(void)
 {
-	if (xen_hvm_domain() && !xen_platform_pci_unplug)
+	if (!xen_has_pv_devices())
 		return -ENODEV;
 
 	ready_to_wait_for_devices = 1;