1 /*
2 * Copyright (c) 2020 - 2023, Nordic Semiconductor ASA
3 * All rights reserved.
4 *
5 * SPDX-License-Identifier: BSD-3-Clause
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright notice, this
11 * list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
18 * contributors may be used to endorse or promote products derived from this
19 * software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 *
33 */
34
35 /**
36 * @file nrf_802154_buffer_allocator.c
37 * @brief Buffer allocation for 802.15.4 receptions and transmissions.
38 */
39
40 #include "nrf_802154_buffer_allocator.h"
41
42 #include "nrf_802154_serialization_crit_sect.h"
43
44 #include <assert.h>
45 #include <stdbool.h>
46 #include <stdint.h>
47
buffer_alloc(nrf_802154_buffer_t * p_buffer_pool,size_t buffer_pool_len)48 static uint8_t * buffer_alloc(nrf_802154_buffer_t * p_buffer_pool, size_t buffer_pool_len)
49 {
50 nrf_802154_buffer_t * p_buffer = NULL;
51 bool success = false;
52 bool retry = false;
53 uint32_t crit_sect = 0UL;
54
55 do
56 {
57 retry = false;
58
59 // Iterate over the buffer pool to search for a free buffer
60 for (uint32_t i = 0; i < buffer_pool_len; i++)
61 {
62 p_buffer = &p_buffer_pool[i];
63
64 if (!p_buffer->taken)
65 {
66 // Free buffer detected. Enter critical section to take it
67 nrf_802154_serialization_crit_sect_enter(&crit_sect);
68
69 if (p_buffer->taken)
70 {
71 // The allocation was preempted and the buffer was taken by higher priority
72 // Reiterate over the buffer pool and search for a free buffer again
73 retry = true;
74 }
75 else
76 {
77 // The allocation can be performed safely
78 p_buffer->taken = true;
79 success = true;
80 }
81
82 nrf_802154_serialization_crit_sect_exit(crit_sect);
83
84 break;
85 }
86 }
87 }
88 while (retry);
89
90 return success ? p_buffer->data : NULL;
91 }
92
buffer_free(nrf_802154_buffer_t * p_buffer_to_free,nrf_802154_buffer_t * p_buffer_pool,size_t buffer_pool_len)93 static void buffer_free(nrf_802154_buffer_t * p_buffer_to_free,
94 nrf_802154_buffer_t * p_buffer_pool,
95 size_t buffer_pool_len)
96 {
97 uint32_t crit_sect = 0UL;
98 size_t idx =
99 ((uintptr_t)p_buffer_to_free - (uintptr_t)p_buffer_pool) / sizeof(nrf_802154_buffer_t);
100
101 assert(idx < buffer_pool_len);
102
103 nrf_802154_serialization_crit_sect_enter(&crit_sect);
104
105 p_buffer_pool[idx].taken = false;
106
107 nrf_802154_serialization_crit_sect_exit(crit_sect);
108 }
109
nrf_802154_buffer_allocator_init(nrf_802154_buffer_allocator_t * p_obj,void * p_memory,size_t memsize)110 void nrf_802154_buffer_allocator_init(nrf_802154_buffer_allocator_t * p_obj,
111 void * p_memory,
112 size_t memsize)
113 {
114 size_t capacity = memsize / sizeof(nrf_802154_buffer_t);
115
116 assert((capacity == 0U) || ((capacity != 0U) && (p_memory != NULL)));
117
118 p_obj->p_memory = p_memory;
119 p_obj->capacity = capacity;
120
121 nrf_802154_buffer_t * p_buffer = (nrf_802154_buffer_t *)p_obj->p_memory;
122
123 for (size_t i = 0; i < p_obj->capacity; i++)
124 {
125 p_buffer[i].taken = false;
126 }
127 }
128
nrf_802154_buffer_allocator_alloc(const nrf_802154_buffer_allocator_t * p_obj)129 void * nrf_802154_buffer_allocator_alloc(const nrf_802154_buffer_allocator_t * p_obj)
130 {
131 return buffer_alloc((nrf_802154_buffer_t *)p_obj->p_memory, p_obj->capacity);
132 }
133
nrf_802154_buffer_allocator_free(const nrf_802154_buffer_allocator_t * p_obj,void * p_buffer)134 void nrf_802154_buffer_allocator_free(const nrf_802154_buffer_allocator_t * p_obj,
135 void * p_buffer)
136 {
137 buffer_free(p_buffer, (nrf_802154_buffer_t *)p_obj->p_memory, p_obj->capacity);
138 }
139
