1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * VMware VMCI Driver
4 *
5 * Copyright (C) 2012 VMware, Inc. All rights reserved.
6 */
7
8#include <linux/slab.h>
9#include "vmci_handle_array.h"
10
11struct vmci_handle_arr *vmci_handle_arr_create(u32 capacity, u32 max_capacity)
12{
13	struct vmci_handle_arr *array;
14
15	if (max_capacity == 0 || capacity > max_capacity)
16		return NULL;
17
18	if (capacity == 0)
19		capacity = min((u32)VMCI_HANDLE_ARRAY_DEFAULT_CAPACITY,
20			       max_capacity);
21
22	array = kmalloc(struct_size(array, entries, capacity), GFP_ATOMIC);
23	if (!array)
24		return NULL;
25
26	array->capacity = capacity;
27	array->max_capacity = max_capacity;
28	array->size = 0;
29
30	return array;
31}
32
33void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
34{
35	kfree(array);
36}
37
38int vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
39				 struct vmci_handle handle)
40{
41	struct vmci_handle_arr *array = *array_ptr;
42
43	if (unlikely(array->size >= array->capacity)) {
44		/* reallocate. */
45		struct vmci_handle_arr *new_array;
46		u32 capacity_bump = min(array->max_capacity - array->capacity,
47					array->capacity);
48		size_t new_size = struct_size(array, entries,
49					      size_add(array->capacity, capacity_bump));
50
51		if (array->size >= array->max_capacity)
52			return VMCI_ERROR_NO_MEM;
53
54		new_array = krealloc(array, new_size, GFP_ATOMIC);
55		if (!new_array)
56			return VMCI_ERROR_NO_MEM;
57
58		new_array->capacity += capacity_bump;
59		*array_ptr = array = new_array;
60	}
61
62	array->entries[array->size] = handle;
63	array->size++;
64
65	return VMCI_SUCCESS;
66}
67
68/*
69 * Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
70 */
71struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
72						struct vmci_handle entry_handle)
73{
74	struct vmci_handle handle = VMCI_INVALID_HANDLE;
75	u32 i;
76
77	for (i = 0; i < array->size; i++) {
78		if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
79			handle = array->entries[i];
80			array->size--;
81			array->entries[i] = array->entries[array->size];
82			array->entries[array->size] = VMCI_INVALID_HANDLE;
83			break;
84		}
85	}
86
87	return handle;
88}
89
90/*
91 * Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
92 */
93struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
94{
95	struct vmci_handle handle = VMCI_INVALID_HANDLE;
96
97	if (array->size) {
98		array->size--;
99		handle = array->entries[array->size];
100		array->entries[array->size] = VMCI_INVALID_HANDLE;
101	}
102
103	return handle;
104}
105
106/*
107 * Handle at given index, VMCI_INVALID_HANDLE if invalid index.
108 */
109struct vmci_handle
110vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, u32 index)
111{
112	if (unlikely(index >= array->size))
113		return VMCI_INVALID_HANDLE;
114
115	return array->entries[index];
116}
117
118bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
119			       struct vmci_handle entry_handle)
120{
121	u32 i;
122
123	for (i = 0; i < array->size; i++)
124		if (vmci_handle_is_equal(array->entries[i], entry_handle))
125			return true;
126
127	return false;
128}
129
130/*
131 * NULL if the array is empty. Otherwise, a pointer to the array
132 * of VMCI handles in the handle array.
133 */
134struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
135{
136	if (array->size)
137		return array->entries;
138
139	return NULL;
140}
141