1  /* SPDX-License-Identifier: GPL-2.0-only */
2  /*
3   * Kernel/userspace transport abstraction for Hyper-V util driver.
4   *
5   * Copyright (C) 2015, Vitaly Kuznetsov <vkuznets@redhat.com>
6   */
7  
8  #ifndef _HV_UTILS_TRANSPORT_H
9  #define _HV_UTILS_TRANSPORT_H
10  
11  #include <linux/connector.h>
12  #include <linux/miscdevice.h>
13  
14  enum hvutil_transport_mode {
15  	HVUTIL_TRANSPORT_INIT = 0,
16  	HVUTIL_TRANSPORT_NETLINK,
17  	HVUTIL_TRANSPORT_CHARDEV,
18  	HVUTIL_TRANSPORT_DESTROY,
19  };
20  
21  struct hvutil_transport {
22  	int mode;                           /* hvutil_transport_mode */
23  	struct file_operations fops;        /* file operations */
24  	struct miscdevice mdev;             /* misc device */
25  	struct cb_id cn_id;                 /* CN_*_IDX/CN_*_VAL */
26  	struct list_head list;              /* hvt_list */
27  	int (*on_msg)(void *, int);         /* callback on new user message */
28  	void (*on_reset)(void);             /* callback when userspace drops */
29  	void (*on_read)(void);              /* callback on message read */
30  	u8 *outmsg;                         /* message to the userspace */
31  	int outmsg_len;                     /* its length */
32  	wait_queue_head_t outmsg_q;         /* poll/read wait queue */
33  	struct mutex lock;                  /* protects struct members */
34  	struct completion release;          /* synchronize with fd release */
35  };
36  
37  struct hvutil_transport *hvutil_transport_init(const char *name,
38  					       u32 cn_idx, u32 cn_val,
39  					       int (*on_msg)(void *, int),
40  					       void (*on_reset)(void));
41  int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len,
42  			  void (*on_read_cb)(void));
43  void hvutil_transport_destroy(struct hvutil_transport *hvt);
44  
45  #endif /* _HV_UTILS_TRANSPORT_H */
46