1/*
2 * VMware VMCI Driver
3 *
4 * Copyright (C) 2012 VMware, Inc. All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation version 2 and no later version.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * for more details.
14 */
15
16#include <linux/slab.h>
17#include "vmci_handle_array.h"
18
19static size_t handle_arr_calc_size(size_t capacity)
20{
21	return sizeof(struct vmci_handle_arr) +
22	    capacity * sizeof(struct vmci_handle);
23}
24
25struct vmci_handle_arr *vmci_handle_arr_create(size_t capacity)
26{
27	struct vmci_handle_arr *array;
28
29	if (capacity == 0)
30		capacity = VMCI_HANDLE_ARRAY_DEFAULT_SIZE;
31
32	array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC);
33	if (!array)
34		return NULL;
35
36	array->capacity = capacity;
37	array->size = 0;
38
39	return array;
40}
41
42void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
43{
44	kfree(array);
45}
46
47void vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
48				  struct vmci_handle handle)
49{
50	struct vmci_handle_arr *array = *array_ptr;
51
52	if (unlikely(array->size >= array->capacity)) {
53		/* reallocate. */
54		struct vmci_handle_arr *new_array;
55		size_t new_capacity = array->capacity * VMCI_ARR_CAP_MULT;
56		size_t new_size = handle_arr_calc_size(new_capacity);
57
58		new_array = krealloc(array, new_size, GFP_ATOMIC);
59		if (!new_array)
60			return;
61
62		new_array->capacity = new_capacity;
63		*array_ptr = array = new_array;
64	}
65
66	array->entries[array->size] = handle;
67	array->size++;
68}
69
70/*
71 * Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
72 */
73struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
74						struct vmci_handle entry_handle)
75{
76	struct vmci_handle handle = VMCI_INVALID_HANDLE;
77	size_t i;
78
79	for (i = 0; i < array->size; i++) {
80		if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
81			handle = array->entries[i];
82			array->size--;
83			array->entries[i] = array->entries[array->size];
84			array->entries[array->size] = VMCI_INVALID_HANDLE;
85			break;
86		}
87	}
88
89	return handle;
90}
91
92/*
93 * Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
94 */
95struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
96{
97	struct vmci_handle handle = VMCI_INVALID_HANDLE;
98
99	if (array->size) {
100		array->size--;
101		handle = array->entries[array->size];
102		array->entries[array->size] = VMCI_INVALID_HANDLE;
103	}
104
105	return handle;
106}
107
108/*
109 * Handle at given index, VMCI_INVALID_HANDLE if invalid index.
110 */
111struct vmci_handle
112vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, size_t index)
113{
114	if (unlikely(index >= array->size))
115		return VMCI_INVALID_HANDLE;
116
117	return array->entries[index];
118}
119
120bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
121			       struct vmci_handle entry_handle)
122{
123	size_t i;
124
125	for (i = 0; i < array->size; i++)
126		if (vmci_handle_is_equal(array->entries[i], entry_handle))
127			return true;
128
129	return false;
130}
131
132/*
133 * NULL if the array is empty. Otherwise, a pointer to the array
134 * of VMCI handles in the handle array.
135 */
136struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
137{
138	if (array->size)
139		return array->entries;
140
141	return NULL;
142}
143