1 /*
2  * Kernel/userspace transport abstraction for Hyper-V util driver.
3  *
4  * Copyright (C) 2015, Vitaly Kuznetsov <vkuznets@redhat.com>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published
8  * by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
13  * NON INFRINGEMENT.  See the GNU General Public License for more
14  * details.
15  *
16  */
17 
18 #ifndef _HV_UTILS_TRANSPORT_H
19 #define _HV_UTILS_TRANSPORT_H
20 
21 #include <linux/connector.h>
22 #include <linux/miscdevice.h>
23 
24 enum hvutil_transport_mode {
25 	HVUTIL_TRANSPORT_INIT = 0,
26 	HVUTIL_TRANSPORT_NETLINK,
27 	HVUTIL_TRANSPORT_CHARDEV,
28 	HVUTIL_TRANSPORT_DESTROY,
29 };
30 
31 struct hvutil_transport {
32 	int mode;                           /* hvutil_transport_mode */
33 	struct file_operations fops;        /* file operations */
34 	struct miscdevice mdev;             /* misc device */
35 	struct cb_id cn_id;                 /* CN_*_IDX/CN_*_VAL */
36 	struct list_head list;              /* hvt_list */
37 	int (*on_msg)(void *, int);         /* callback on new user message */
38 	void (*on_reset)(void);             /* callback when userspace drops */
39 	void (*on_read)(void);              /* callback on message read */
40 	u8 *outmsg;                         /* message to the userspace */
41 	int outmsg_len;                     /* its length */
42 	wait_queue_head_t outmsg_q;         /* poll/read wait queue */
43 	struct mutex lock;                  /* protects struct members */
44 	struct completion release;          /* synchronize with fd release */
45 };
46 
47 struct hvutil_transport *hvutil_transport_init(const char *name,
48 					       u32 cn_idx, u32 cn_val,
49 					       int (*on_msg)(void *, int),
50 					       void (*on_reset)(void));
51 int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len,
52 			  void (*on_read_cb)(void));
53 void hvutil_transport_destroy(struct hvutil_transport *hvt);
54 
55 #endif /* _HV_UTILS_TRANSPORT_H */
56