linux/drivers/misc/vmw_vmci/vmci_event.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * VMware VMCI Driver
 *
 * Copyright (C) 2012 VMware, Inc. All rights reserved.
 */

#include <linux/vmw_vmci_defs.h>
#include <linux/vmw_vmci_api.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/nospec.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/rculist.h>

#include "vmci_driver.h"
#include "vmci_event.h"

#define EVENT_MAGIC …
#define VMCI_EVENT_MAX_ATTEMPTS …

struct vmci_subscription { … };

static struct list_head subscriber_array[VMCI_EVENT_MAX];
static DEFINE_MUTEX(subscriber_mutex);

int __init vmci_event_init(void)
{ … }

void vmci_event_exit(void)
{ … }

/*
 * Find entry. Assumes subscriber_mutex is held.
 */
static struct vmci_subscription *event_find(u32 sub_id)
{ … }

/*
 * Actually delivers the events to the subscribers.
 * The callback function for each subscriber is invoked.
 */
static void event_deliver(struct vmci_event_msg *event_msg)
{ … }

/*
 * Dispatcher for the VMCI_EVENT_RECEIVE datagrams. Calls all
 * subscribers for given event.
 */
int vmci_event_dispatch(struct vmci_datagram *msg)
{ … }

/*
 * vmci_event_subscribe() - Subscribe to a given event.
 * @event:      The event to subscribe to.
 * @callback:   The callback to invoke upon the event.
 * @callback_data:      Data to pass to the callback.
 * @subscription_id:    ID used to track subscription.  Used with
 *              vmci_event_unsubscribe()
 *
 * Subscribes to the provided event. The callback specified will be
 * fired from RCU critical section and therefore must not sleep.
 */
int vmci_event_subscribe(u32 event,
			 vmci_event_cb callback,
			 void *callback_data,
			 u32 *new_subscription_id)
{ … }
EXPORT_SYMBOL_GPL(…);

/*
 * vmci_event_unsubscribe() - unsubscribe from an event.
 * @sub_id:     A subscription ID as provided by vmci_event_subscribe()
 *
 * Unsubscribe from given event. Removes it from list and frees it.
 * Will return callback_data if requested by caller.
 */
int vmci_event_unsubscribe(u32 sub_id)
{ … }
EXPORT_SYMBOL_GPL(…);