From mboxrd@z Thu Jan 1 00:00:00 1970 From: clabbe.montjoie@gmail.com (Corentin Labbe) Date: Wed, 3 Jan 2018 21:11:04 +0100 Subject: [PATCH 1/6] Documentation: crypto: document crypto engine API In-Reply-To: <20180103201109.16077-1-clabbe.montjoie@gmail.com> References: <20180103201109.16077-1-clabbe.montjoie@gmail.com> Message-ID: <20180103201109.16077-2-clabbe.montjoie@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Signed-off-by: Corentin Labbe --- Documentation/crypto/crypto_engine.rst | 46 ++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 Documentation/crypto/crypto_engine.rst diff --git a/Documentation/crypto/crypto_engine.rst b/Documentation/crypto/crypto_engine.rst new file mode 100644 index 000000000000..b0ed37f9fb0c --- /dev/null +++ b/Documentation/crypto/crypto_engine.rst @@ -0,0 +1,46 @@ +============= +CRYPTO ENGINE +============= + +Overview +-------- +The crypto engine API (CE), is a crypto queue manager. + +Requirement +----------- +You have to put at start of your tfm_ctx the struct crypto_engine_reqctx +struct your_tfm_ctx { + struct crypto_engine_reqctx enginectx; + ... +}; +Why: Since CE manage only crypto_async_request, it cannot know the underlying +request_type and so have access only on the TFM. +So using container_of for accessing __ctx is impossible. +Furthermore, the crypto engine cannot know the "struct your_tfm_ctx", +so it must assume that crypto_engine_reqctx is at start of it. + +Order of operations +------------------- +You have to obtain a struct crypto_engine via crypto_engine_alloc_init(). +And start it via crypto_engine_start(). + +Before transferring any request, you have to fill the enginectx. +- prepare_request: (taking a function pointer) If you need to do some processing before doing the request +- unprepare_request: (taking a function pointer) Undoing what's done in prepare_request +- do_one_request: (taking a function pointer) Do encryption for current request + +Note: that those three functions get the crypto_async_request associated with the received request. +So your need to get the original request via container_of(areq, struct yourrequesttype_request, base); + +When your driver receive a crypto_request, you have to transfer it to +the cryptoengine via one of: +- crypto_transfer_cipher_request_to_engine() +- crypto_transfer_skcipher_request_to_engine() +- crypto_transfer_akcipher_request_to_engine() +- crypto_transfer_hash_request_to_engine() + +At the end of the request process, a call to one of the following function is needed: +- crypto_finalize_cipher_request +- crypto_finalize_skcipher_request +- crypto_finalize_akcipher_request +- crypto_finalize_hash_request -- 2.13.6