1.. SPDX-License-Identifier: GPL-2.0 2 3Crypto Engine 4============= 5 6Overview 7-------- 8The crypto engine (CE) API is a crypto queue manager. 9 10Requirement 11----------- 12You must put, at the start of your transform context your_tfm_ctx, the structure 13crypto_engine: 14 15:: 16 17 struct your_tfm_ctx { 18 struct crypto_engine engine; 19 ... 20 }; 21 22The crypto engine only manages asynchronous requests in the form of 23crypto_async_request. It cannot know the underlying request type and thus only 24has access to the transform structure. It is not possible to access the context 25using container_of. In addition, the engine knows nothing about your 26structure "``struct your_tfm_ctx``". The engine assumes (requires) the placement 27of the known member ``struct crypto_engine`` at the beginning. 28 29Order of operations 30------------------- 31You are required to obtain a struct crypto_engine via ``crypto_engine_alloc_init()``. 32Start it via ``crypto_engine_start()``. When finished with your work, shut down the 33engine using ``crypto_engine_stop()`` and destroy the engine with 34``crypto_engine_exit()``. 35 36Before transferring any request, you have to fill the context enginectx by 37providing functions for the following: 38 39* ``prepare_crypt_hardware``: Called once before any prepare functions are 40 called. 41 42* ``unprepare_crypt_hardware``: Called once after all unprepare functions have 43 been called. 44 45* ``prepare_cipher_request``/``prepare_hash_request``: Called before each 46 corresponding request is performed. If some processing or other preparatory 47 work is required, do it here. 48 49* ``unprepare_cipher_request``/``unprepare_hash_request``: Called after each 50 request is handled. Clean up / undo what was done in the prepare function. 51 52* ``cipher_one_request``/``hash_one_request``: Handle the current request by 53 performing the operation. 54 55Note that these functions access the crypto_async_request structure 56associated with the received request. You are able to retrieve the original 57request by using: 58 59:: 60 61 container_of(areq, struct yourrequesttype_request, base); 62 63When your driver receives a crypto_request, you must to transfer it to 64the crypto engine via one of: 65 66* crypto_transfer_aead_request_to_engine() 67 68* crypto_transfer_akcipher_request_to_engine() 69 70* crypto_transfer_hash_request_to_engine() 71 72* crypto_transfer_skcipher_request_to_engine() 73 74At the end of the request process, a call to one of the following functions is needed: 75 76* crypto_finalize_aead_request() 77 78* crypto_finalize_akcipher_request() 79 80* crypto_finalize_hash_request() 81 82* crypto_finalize_skcipher_request() 83