1 /*
2 * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include "esp_crypto_shared_gdma.h"
8
9 #include "freertos/FreeRTOS.h"
10 #include "freertos/task.h"
11
12 #include "hal/gdma_ll.h"
13 #include "soc/soc_caps.h"
14 #include "esp_log.h"
15 #include "esp_err.h"
16 #include "esp_crypto_lock.h"
17
18 #define NEW_CHANNEL_TIMEOUT_MS 1000
19 #define NEW_CHANNEL_DELAY_MS 100
20
21 static const char *TAG = "crypto_shared_gdma";
22
23 static gdma_channel_handle_t rx_channel;
24 static gdma_channel_handle_t tx_channel;
25
26 /* Allocate a new GDMA channel, will keep trying until NEW_CHANNEL_TIMEOUT_MS */
crypto_shared_gdma_new_channel(gdma_channel_alloc_config_t * channel_config,gdma_channel_handle_t * channel)27 static inline esp_err_t crypto_shared_gdma_new_channel(gdma_channel_alloc_config_t *channel_config, gdma_channel_handle_t *channel)
28 {
29 esp_err_t ret;
30 int time_waited_ms = 0;
31
32 while (1) {
33 ret = gdma_new_channel(channel_config, channel);
34
35 if (ret == ESP_OK) {
36 break;
37 } else if (time_waited_ms >= NEW_CHANNEL_TIMEOUT_MS) {
38 *channel = NULL;
39 break;
40 }
41
42 time_waited_ms += NEW_CHANNEL_DELAY_MS;
43 vTaskDelay(NEW_CHANNEL_DELAY_MS / portTICK_PERIOD_MS);
44 }
45 return ret;
46 }
47
48 /* Initialize GDMA module and channels */
crypto_shared_gdma_init(void)49 static esp_err_t crypto_shared_gdma_init(void)
50 {
51 esp_err_t ret;
52
53 gdma_channel_alloc_config_t channel_config_tx = {
54 .direction = GDMA_CHANNEL_DIRECTION_TX,
55 };
56
57 gdma_channel_alloc_config_t channel_config_rx = {
58 .direction = GDMA_CHANNEL_DIRECTION_RX,
59 };
60
61 gdma_transfer_ability_t transfer_ability = {
62 .sram_trans_align = 1,
63 };
64
65
66 ret = crypto_shared_gdma_new_channel(&channel_config_tx, &tx_channel);
67 if (ret != ESP_OK) {
68 goto err;
69 }
70
71 ret = crypto_shared_gdma_new_channel(&channel_config_rx, &rx_channel);
72 if (ret != ESP_OK) {
73 gdma_del_channel(tx_channel); // Clean up already allocated TX channel
74 goto err;
75 }
76
77
78 gdma_set_transfer_ability(tx_channel, &transfer_ability);
79 gdma_set_transfer_ability(rx_channel, &transfer_ability);
80
81 gdma_connect(rx_channel, GDMA_MAKE_TRIGGER(GDMA_TRIG_PERIPH_AES, 0));
82 gdma_connect(tx_channel, GDMA_MAKE_TRIGGER(GDMA_TRIG_PERIPH_AES, 0));
83
84 return ESP_OK;
85
86 err:
87 ESP_LOGE(TAG, "Failed to acquire DMA channel, Err=%d", ret);
88 tx_channel = NULL;
89 rx_channel = NULL;
90
91 return ret;
92 }
93
94
esp_crypto_shared_gdma_start(const lldesc_t * input,const lldesc_t * output,gdma_trigger_peripheral_t peripheral)95 esp_err_t esp_crypto_shared_gdma_start(const lldesc_t *input, const lldesc_t *output, gdma_trigger_peripheral_t peripheral)
96 {
97 int rx_ch_id = 0;
98 esp_err_t ret = ESP_OK;
99
100 if (tx_channel == NULL) {
101 /* Allocate a pair of RX and TX for crypto, should only happen the first time we use the GMDA
102 or if user called esp_crypto_shared_gdma_release */
103 ret = crypto_shared_gdma_init();
104 }
105
106 if (ret != ESP_OK) {
107 return ret;
108 }
109
110 /* Tx channel is shared between AES and SHA, need to connect to peripheral every time */
111 gdma_disconnect(tx_channel);
112
113 if (peripheral == GDMA_TRIG_PERIPH_SHA) {
114 gdma_connect(tx_channel, GDMA_MAKE_TRIGGER(GDMA_TRIG_PERIPH_SHA, 0));
115 } else if (peripheral == GDMA_TRIG_PERIPH_AES) {
116 gdma_connect(tx_channel, GDMA_MAKE_TRIGGER(GDMA_TRIG_PERIPH_AES, 0));
117 } else {
118 return ESP_ERR_INVALID_ARG;
119 }
120
121 /* tx channel is reset by gdma_connect(), also reset rx to ensure a known state */
122 gdma_get_channel_id(rx_channel, &rx_ch_id);
123 gdma_ll_rx_reset_channel(&GDMA, rx_ch_id);
124
125 gdma_start(tx_channel, (intptr_t)input);
126 gdma_start(rx_channel, (intptr_t)output);
127
128 return ESP_OK;
129 }
130
esp_crypto_shared_gdma_free()131 void esp_crypto_shared_gdma_free()
132 {
133 esp_crypto_sha_aes_lock_acquire();
134
135 if (rx_channel != NULL) {
136 gdma_disconnect(rx_channel);
137 gdma_del_channel(rx_channel);
138 rx_channel = NULL;
139 }
140
141 if (tx_channel != NULL) {
142 gdma_disconnect(tx_channel);
143 gdma_del_channel(tx_channel);
144 tx_channel = NULL;
145 }
146
147 esp_crypto_sha_aes_lock_release();
148 }
149
