linux/drivers/misc/vmw_vmci/vmci_resource.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/hash.h>
#include <linux/types.h>
#include <linux/rculist.h>
#include <linux/completion.h>

#include "vmci_resource.h"
#include "vmci_driver.h"


#define VMCI_RESOURCE_HASH_BITS …
#define VMCI_RESOURCE_HASH_BUCKETS …

struct vmci_hash_table { … };

static struct vmci_hash_table vmci_resource_table = …;

static unsigned int vmci_resource_hash(struct vmci_handle handle)
{ … }

/*
 * Gets a resource (if one exists) matching given handle from the hash table.
 */
static struct vmci_resource *vmci_resource_lookup(struct vmci_handle handle,
						  enum vmci_resource_type type)
{ … }

/*
 * Find an unused resource ID and return it. The first
 * VMCI_RESERVED_RESOURCE_ID_MAX are reserved so we start from
 * its value + 1.
 * Returns VMCI resource id on success, VMCI_INVALID_ID on failure.
 */
static u32 vmci_resource_find_id(u32 context_id,
				 enum vmci_resource_type resource_type)
{ … }


int vmci_resource_add(struct vmci_resource *resource,
		      enum vmci_resource_type resource_type,
		      struct vmci_handle handle)

{ … }

void vmci_resource_remove(struct vmci_resource *resource)
{ … }

struct vmci_resource *
vmci_resource_by_handle(struct vmci_handle resource_handle,
			enum vmci_resource_type resource_type)
{ … }

/*
 * Get a reference to given resource.
 */
struct vmci_resource *vmci_resource_get(struct vmci_resource *resource)
{ … }

static void vmci_release_resource(struct kref *kref)
{ … }

/*
 * Resource's release function will get called if last reference.
 * If it is the last reference, then we are sure that nobody else
 * can increment the count again (it's gone from the resource hash
 * table), so there's no need for locking here.
 */
int vmci_resource_put(struct vmci_resource *resource)
{ … }

struct vmci_handle vmci_resource_handle(struct vmci_resource *resource)
{ … }