rapidio/rionet: add shutdown event handling

Add shutdown notification handler which terminates active connections
with remote RapidIO nodes.  This prevents remote nodes from sending
packets to the powered off node and eliminates hardware error events on
remote nodes.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/net/rionet.c

@@ -24,6 +24,7 @@
 #include <linux/skbuff.h>
 #include <linux/crc32.h>
 #include <linux/ethtool.h>
+#include <linux/reboot.h>
 
 #define DRV_NAME        "rionet"
 #define DRV_VERSION     "0.3"
@@ -599,6 +600,30 @@ static int rionet_add_dev(struct device *dev, struct subsys_interface *sif)
 	return rc;
 }
 
+static int rionet_shutdown(struct notifier_block *nb, unsigned long code,
+			   void *unused)
+{
+	struct rionet_peer *peer, *tmp;
+	int i;
+
+	pr_debug("%s: %s\n", DRV_NAME, __func__);
+
+	for (i = 0; i < RIONET_MAX_NETS; i++) {
+		if (!nets[i].ndev)
+			continue;
+
+		list_for_each_entry_safe(peer, tmp, &nets[i].peers, node) {
+			if (nets[i].active[peer->rdev->destid]) {
+				rio_send_doorbell(peer->rdev,
+						  RIONET_DOORBELL_LEAVE);
+				nets[i].active[peer->rdev->destid] = NULL;
+			}
+		}
+	}
+
+	return NOTIFY_DONE;
+}
+
 #ifdef MODULE
 static struct rio_device_id rionet_id_table[] = {
 	{RIO_DEVICE(RIO_ANY_ID, RIO_ANY_ID)},
@@ -615,8 +640,20 @@ static struct subsys_interface rionet_interface = {
 	.remove_dev	= rionet_remove_dev,
 };
 
+static struct notifier_block rionet_notifier = {
+	.notifier_call = rionet_shutdown,
+};
+
 static int __init rionet_init(void)
 {
+	int ret;
+
+	ret = register_reboot_notifier(&rionet_notifier);
+	if (ret) {
+		pr_err("%s: failed to register reboot notifier (err=%d)\n",
+		       DRV_NAME, ret);
+		return ret;
+	}
 	return subsys_interface_register(&rionet_interface);
 }
 
@@ -648,6 +685,7 @@ static void __exit rionet_exit(void)
 		}
 	}
 
+	unregister_reboot_notifier(&rionet_notifier);
 	subsys_interface_unregister(&rionet_interface);
 }