summaryrefslogtreecommitdiff
path: root/drivers/misc/vmw_vmci/vmci_handle_array.c
blob: 917e18a8af9523231095a82e7d647ab3c32ba73f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/*
 * VMware VMCI Driver
 *
 * Copyright (C) 2012 VMware, Inc. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation version 2 and no later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 */

#include <linux/slab.h>
#include "vmci_handle_array.h"

static size_t handle_arr_calc_size(u32 capacity)
{
	return VMCI_HANDLE_ARRAY_HEADER_SIZE +
	    capacity * sizeof(struct vmci_handle);
}

struct vmci_handle_arr *vmci_handle_arr_create(u32 capacity, u32 max_capacity)
{
	struct vmci_handle_arr *array;

	if (max_capacity == 0 || capacity > max_capacity)
		return NULL;

	if (capacity == 0)
		capacity = min((u32)VMCI_HANDLE_ARRAY_DEFAULT_CAPACITY,
			       max_capacity);

	array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC);
	if (!array)
		return NULL;

	array->capacity = capacity;
	array->max_capacity = max_capacity;
	array->size = 0;

	return array;
}

void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
{
	kfree(array);
}

int vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
				 struct vmci_handle handle)
{
	struct vmci_handle_arr *array = *array_ptr;

	if (unlikely(array->size >= array->capacity)) {
		/* reallocate. */
		struct vmci_handle_arr *new_array;
		u32 capacity_bump = min(array->max_capacity - array->capacity,
					array->capacity);
		size_t new_size = handle_arr_calc_size(array->capacity +
						       capacity_bump);

		if (array->size >= array->max_capacity)
			return VMCI_ERROR_NO_MEM;

		new_array = krealloc(array, new_size, GFP_ATOMIC);
		if (!new_array)
			return VMCI_ERROR_NO_MEM;

		new_array->capacity += capacity_bump;
		*array_ptr = array = new_array;
	}

	array->entries[array->size] = handle;
	array->size++;

	return VMCI_SUCCESS;
}

/*
 * Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
 */
struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
						struct vmci_handle entry_handle)
{
	struct vmci_handle handle = VMCI_INVALID_HANDLE;
	u32 i;

	for (i = 0; i < array->size; i++) {
		if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
			handle = array->entries[i];
			array->size--;
			array->entries[i] = array->entries[array->size];
			array->entries[array->size] = VMCI_INVALID_HANDLE;
			break;
		}
	}

	return handle;
}

/*
 * Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
 */
struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
{
	struct vmci_handle handle = VMCI_INVALID_HANDLE;

	if (array->size) {
		array->size--;
		handle = array->entries[array->size];
		array->entries[array->size] = VMCI_INVALID_HANDLE;
	}

	return handle;
}

/*
 * Handle at given index, VMCI_INVALID_HANDLE if invalid index.
 */
struct vmci_handle
vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, u32 index)
{
	if (unlikely(index >= array->size))
		return VMCI_INVALID_HANDLE;

	return array->entries[index];
}

bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
			       struct vmci_handle entry_handle)
{
	u32 i;

	for (i = 0; i < array->size; i++)
		if (vmci_handle_is_equal(array->entries[i], entry_handle))
			return true;

	return false;
}

/*
 * NULL if the array is empty. Otherwise, a pointer to the array
 * of VMCI handles in the handle array.
 */
struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
{
	if (array->size)
		return array->entries;

	return NULL;
}