esp-idf/components/mbedtls/port/include/esp_crypto_shared_gdma.h
Marius Vikhammer 1c8fd4041e aes/sha: use a shared lazy allocated GDMA channel for AES and SHA
Removed the old dynamically allocated GDMA channel approach.
It proved too unreliable as we couldn't not ensure consumers of the mbedtls
would properly free the channels after use.

Replaced by a single shared GDMA channel for AES and SHA, which won't be
released unless user specifically calls API for releasing it.
2021-03-10 09:40:35 +08:00

56 lines
2.1 KiB
C

// Copyright 2021 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#pragma once
#include "soc/lldesc.h"
#include "esp_private/gdma.h"
#include "esp_err.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Start a GDMA transfer on the shared crypto DMA channel
*
* @note Will allocate a GDMA channel for AES & SHA if no such channel is already allocated
*
* @param input Input linked list descriptor
* @param output Output linked list descriptor
* @param peripheral Crypto peripheral to connect the DMA to, either GDMA_TRIG_PERIPH_AES or
* GDMA_TRIG_PERIPH_SHA
* @return esp_err_t ESP_FAIL if no GDMA channel available
*/
esp_err_t esp_crypto_shared_gdma_start(const lldesc_t *input, const lldesc_t *output, gdma_trigger_peripheral_t peripheral);
/**
* @brief Frees any shared crypto DMA channel, if esp_crypto_shared_gdma_start is called after
* this, new GDMA channels will be allocated.
*
* @note Function is meant to be called from user code, and thus takes AES/SHA lock.
* This means this function should not be called from code which already takes these locks,
* i.e. inside our AES/SHA code.
*
* If you are continously using AES/SHA (e.g. because of a wifi connection) then it's not recommended
* to use this API. Freeing the channel is mainly for use cases where you are finished with the crypto peripherals
* and need the DMA channel for other peripherals. An example would be doing some processing after disconnecting WiFi
*/
void esp_crypto_shared_gdma_free(void);
#ifdef __cplusplus
}
#endif