The CESA IP supports CPU offload through a dedicated DMA engine (TDMA)
which can control the crypto block.
When you use this mode, all the required data (operation metadata and
payload data) are transferred using DMA, and the results are retrieved
through DMA when possible (hash results are not retrieved through DMA yet),
thus reducing the involvement of the CPU and providing better performances
in most cases (for small requests, the cost of DMA preparation might
exceed the performance gain).
Note that some CESA IPs do not embed this dedicated DMA, hence the
activation of this feature on a per platform basis.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The existing mv_cesa driver supports some features of the CESA IP but is
quite limited, and reworking it to support new features (like involving the
TDMA engine to offload the CPU) is almost impossible.
This driver has been rewritten from scratch to take those new features into
account.
This commit introduce the base infrastructure allowing us to add support
for DMA optimization.
It also includes support for one hash (SHA1) and one cipher (AES)
algorithm, and enable those features on the Armada 370 SoC.
Other algorithms and platforms will be added later on.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
