drivers/hv/hv_utils_transport.h

   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 */