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