xref: /linux/drivers/hv/hv_utils_transport.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 };
29 
30 struct hvutil_transport {
31 	int mode;                           /* hvutil_transport_mode */
32 	struct file_operations fops;        /* file operations */
33 	struct miscdevice mdev;             /* misc device */
34 	struct cb_id cn_id;                 /* CN_*_IDX/CN_*_VAL */
35 	struct list_head list;              /* hvt_list */
36 	int (*on_msg)(void *, int);         /* callback on new user message */
37 	void (*on_reset)(void);             /* callback when userspace drops */
38 	u8 *outmsg;                         /* message to the userspace */
39 	int outmsg_len;                     /* its length */
40 	wait_queue_head_t outmsg_q;         /* poll/read wait queue */
41 	struct mutex outmsg_lock;           /* protects outmsg */
42 };
43 
44 struct hvutil_transport *hvutil_transport_init(const char *name,
45 					       u32 cn_idx, u32 cn_val,
46 					       int (*on_msg)(void *, int),
47 					       void (*on_reset)(void));
48 int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len);
49 void hvutil_transport_destroy(struct hvutil_transport *hvt);
50 
51 #endif /* _HV_UTILS_TRANSPORT_H */
52