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
11static size_t handle_arr_calc_size(u32 capacity)
12{
13	return VMCI_HANDLE_ARRAY_HEADER_SIZE +
14	    capacity * sizeof(struct vmci_handle);
15}
16
17struct vmci_handle_arr *vmci_handle_arr_create(u32 capacity, u32 max_capacity)
18{
19	struct vmci_handle_arr *array;
20
21	if (max_capacity == 0 || capacity > max_capacity)
22		return NULL;
23
24	if (capacity == 0)
25		capacity = min((u32)VMCI_HANDLE_ARRAY_DEFAULT_CAPACITY,
26			       max_capacity);
27
28	array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC);
29	if (!array)
30		return NULL;
31
32	array->capacity = capacity;
33	array->max_capacity = max_capacity;
34	array->size = 0;
35
36	return array;
37}
38
39void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
40{
41	kfree(array);
42}
43
44int vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
45				 struct vmci_handle handle)
46{
47	struct vmci_handle_arr *array = *array_ptr;
48
49	if (unlikely(array->size >= array->capacity)) {
50		/* reallocate. */
51		struct vmci_handle_arr *new_array;
52		u32 capacity_bump = min(array->max_capacity - array->capacity,
53					array->capacity);
54		size_t new_size = handle_arr_calc_size(array->capacity +
55						       capacity_bump);
56
57		if (array->size >= array->max_capacity)
58			return VMCI_ERROR_NO_MEM;
59
60		new_array = krealloc(array, new_size, GFP_ATOMIC);
61		if (!new_array)
62			return VMCI_ERROR_NO_MEM;
63
64		new_array->capacity += capacity_bump;
65		*array_ptr = array = new_array;
66	}
67
68	array->entries[array->size] = handle;
69	array->size++;
70
71	return VMCI_SUCCESS;
72}
73
74/*
75 * Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
76 */
77struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
78						struct vmci_handle entry_handle)
79{
80	struct vmci_handle handle = VMCI_INVALID_HANDLE;
81	u32 i;
82
83	for (i = 0; i < array->size; i++) {
84		if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
85			handle = array->entries[i];
86			array->size--;
87			array->entries[i] = array->entries[array->size];
88			array->entries[array->size] = VMCI_INVALID_HANDLE;
89			break;
90		}
91	}
92
93	return handle;
94}
95
96/*
97 * Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
98 */
99struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
100{
101	struct vmci_handle handle = VMCI_INVALID_HANDLE;
102
103	if (array->size) {
104		array->size--;
105		handle = array->entries[array->size];
106		array->entries[array->size] = VMCI_INVALID_HANDLE;
107	}
108
109	return handle;
110}
111
112/*
113 * Handle at given index, VMCI_INVALID_HANDLE if invalid index.
114 */
115struct vmci_handle
116vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, u32 index)
117{
118	if (unlikely(index >= array->size))
119		return VMCI_INVALID_HANDLE;
120
121	return array->entries[index];
122}
123
124bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
125			       struct vmci_handle entry_handle)
126{
127	u32 i;
128
129	for (i = 0; i < array->size; i++)
130		if (vmci_handle_is_equal(array->entries[i], entry_handle))
131			return true;
132
133	return false;
134}
135
136/*
137 * NULL if the array is empty. Otherwise, a pointer to the array
138 * of VMCI handles in the handle array.
139 */
140struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
141{
142	if (array->size)
143		return array->entries;
144
145	return NULL;
146}
147