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
14enum hvutil_transport_mode {
15	HVUTIL_TRANSPORT_INIT = 0,
16	HVUTIL_TRANSPORT_NETLINK,
17	HVUTIL_TRANSPORT_CHARDEV,
18	HVUTIL_TRANSPORT_DESTROY,
19};
20
21struct 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
37struct 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));
41int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len,
42			  void (*on_read_cb)(void));
43void hvutil_transport_destroy(struct hvutil_transport *hvt);
44
45#endif /* _HV_UTILS_TRANSPORT_H */
46