virtio: clarify that ABI is usable by any implementations

We want others to implement and use virtio, so it makes sense to BSD
license the non-__KERNEL__ parts of the headers to make this crystal
clear.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Mark McLoughlin <markmc@redhat.com>
Acked-by: Ryan Harper <ryanh@us.ibm.com>
Acked-by: Eric Van Hensbergen <ericvh@gmail.com>
Acked-by: Anthony Liguori <aliguori@us.ibm.com>

include/linux/virtio_9p.h

 #ifndef _LINUX_VIRTIO_9P_H
 #define _LINUX_VIRTIO_9P_H
+/* This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers. */
 #include <linux/virtio_config.h>
 
 /* The ID for virtio console */

include/linux/virtio_balloon.h

 #ifndef _LINUX_VIRTIO_BALLOON_H
 #define _LINUX_VIRTIO_BALLOON_H
+/* This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers. */
 #include <linux/virtio_config.h>
 
 /* The ID for virtio_balloon */

include/linux/virtio_blk.h

 #ifndef _LINUX_VIRTIO_BLK_H
 #define _LINUX_VIRTIO_BLK_H
+/* This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers. */
 #include <linux/virtio_config.h>
 
 /* The ID for virtio_block */

include/linux/virtio_config.h

 #ifndef _LINUX_VIRTIO_CONFIG_H
 #define _LINUX_VIRTIO_CONFIG_H
+/* This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
+ * anyone can use the definitions to implement compatible drivers/servers. */
+
 /* Virtio devices use a standardized configuration space to define their
  * features and pass configuration information, but each implementation can
  * store and access that space differently. */

include/linux/virtio_console.h

 #ifndef _LINUX_VIRTIO_CONSOLE_H
 #define _LINUX_VIRTIO_CONSOLE_H
 #include <linux/virtio_config.h>
+/* This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
+ * anyone can use the definitions to implement compatible drivers/servers. */
 
 /* The ID for virtio console */
 #define VIRTIO_ID_CONSOLE	3

include/linux/virtio_net.h

 #ifndef _LINUX_VIRTIO_NET_H
 #define _LINUX_VIRTIO_NET_H
+/* This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers. */
 #include <linux/virtio_config.h>
 
 /* The ID for virtio_net */

include/linux/virtio_pci.h

@@ -9,9 +9,8 @@
  * Authors:
  *  Anthony Liguori  <aliguori@us.ibm.com>
  *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- *
+ * This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers.
  */
 
 #ifndef _LINUX_VIRTIO_PCI_H

include/linux/virtio_rng.h

 #ifndef _LINUX_VIRTIO_RNG_H
 #define _LINUX_VIRTIO_RNG_H
+/* This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers. */
 #include <linux/virtio_config.h>
 
 /* The ID for virtio_rng */