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
handle_arr_calc_size(u32 capacity)19 static size_t handle_arr_calc_size(u32 capacity)
20 {
21 return VMCI_HANDLE_ARRAY_HEADER_SIZE +
22 capacity * sizeof(struct vmci_handle);
23 }
24
vmci_handle_arr_create(u32 capacity,u32 max_capacity)25 struct vmci_handle_arr *vmci_handle_arr_create(u32 capacity, u32 max_capacity)
26 {
27 struct vmci_handle_arr *array;
28
29 if (max_capacity == 0 || capacity > max_capacity)
30 return NULL;
31
32 if (capacity == 0)
33 capacity = min((u32)VMCI_HANDLE_ARRAY_DEFAULT_CAPACITY,
34 max_capacity);
35
36 array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC);
37 if (!array)
38 return NULL;
39
40 array->capacity = capacity;
41 array->max_capacity = max_capacity;
42 array->size = 0;
43
44 return array;
45 }
46
vmci_handle_arr_destroy(struct vmci_handle_arr * array)47 void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
48 {
49 kfree(array);
50 }
51
vmci_handle_arr_append_entry(struct vmci_handle_arr ** array_ptr,struct vmci_handle handle)52 int vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
53 struct vmci_handle handle)
54 {
55 struct vmci_handle_arr *array = *array_ptr;
56
57 if (unlikely(array->size >= array->capacity)) {
58 /* reallocate. */
59 struct vmci_handle_arr *new_array;
60 u32 capacity_bump = min(array->max_capacity - array->capacity,
61 array->capacity);
62 size_t new_size = handle_arr_calc_size(array->capacity +
63 capacity_bump);
64
65 if (array->size >= array->max_capacity)
66 return VMCI_ERROR_NO_MEM;
67
68 new_array = krealloc(array, new_size, GFP_ATOMIC);
69 if (!new_array)
70 return VMCI_ERROR_NO_MEM;
71
72 new_array->capacity += capacity_bump;
73 *array_ptr = array = new_array;
74 }
75
76 array->entries[array->size] = handle;
77 array->size++;
78
79 return VMCI_SUCCESS;
80 }
81
82 /*
83 * Handle that was removed, VMCI_INVALID_HANDLE if entry not found.
84 */
vmci_handle_arr_remove_entry(struct vmci_handle_arr * array,struct vmci_handle entry_handle)85 struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
86 struct vmci_handle entry_handle)
87 {
88 struct vmci_handle handle = VMCI_INVALID_HANDLE;
89 u32 i;
90
91 for (i = 0; i < array->size; i++) {
92 if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
93 handle = array->entries[i];
94 array->size--;
95 array->entries[i] = array->entries[array->size];
96 array->entries[array->size] = VMCI_INVALID_HANDLE;
97 break;
98 }
99 }
100
101 return handle;
102 }
103
104 /*
105 * Handle that was removed, VMCI_INVALID_HANDLE if array was empty.
106 */
vmci_handle_arr_remove_tail(struct vmci_handle_arr * array)107 struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
108 {
109 struct vmci_handle handle = VMCI_INVALID_HANDLE;
110
111 if (array->size) {
112 array->size--;
113 handle = array->entries[array->size];
114 array->entries[array->size] = VMCI_INVALID_HANDLE;
115 }
116
117 return handle;
118 }
119
120 /*
121 * Handle at given index, VMCI_INVALID_HANDLE if invalid index.
122 */
123 struct vmci_handle
vmci_handle_arr_get_entry(const struct vmci_handle_arr * array,u32 index)124 vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, u32 index)
125 {
126 if (unlikely(index >= array->size))
127 return VMCI_INVALID_HANDLE;
128
129 return array->entries[index];
130 }
131
vmci_handle_arr_has_entry(const struct vmci_handle_arr * array,struct vmci_handle entry_handle)132 bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
133 struct vmci_handle entry_handle)
134 {
135 u32 i;
136
137 for (i = 0; i < array->size; i++)
138 if (vmci_handle_is_equal(array->entries[i], entry_handle))
139 return true;
140
141 return false;
142 }
143
144 /*
145 * NULL if the array is empty. Otherwise, a pointer to the array
146 * of VMCI handles in the handle array.
147 */
vmci_handle_arr_get_handles(struct vmci_handle_arr * array)148 struct vmci_handle *vmci_handle_arr_get_handles(struct vmci_handle_arr *array)
149 {
150 if (array->size)
151 return array->entries;
152
153 return NULL;
154 }
155