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3525fe4752
Due to a lack of alignment in the data sent by requests, the actual DMA support of the STM32 hash driver is only working with digest calls. This patch, based on the algorithm used in the driver omap-sham.c, allows for the usage of DMA in any situation. It has been functionally tested on STM32MP15, STM32MP13 and STM32MP25. By checking the performance of this new driver with OpenSSL, the following results were found: Performance: (datasize: 4096, number of hashes performed in 10s) |type |no DMA |DMA support|software | |-------|----------|-----------|----------| |md5 |13873.56k |10958.03k |71163.08k | |sha1 |13796.15k |10729.47k |39670.58k | |sha224 |13737.98k |10775.76k |22094.64k | |sha256 |13655.65k |10872.01k |22075.39k | CPU Usage: (algorithm used: sha256, computation time: 20s, measurement taken at ~10s) |datasize |no DMA |DMA | software | |----------|-------|-----|----------| | 2048 | 56% | 49% | 50% | | 4096 | 54% | 46% | 50% | | 8192 | 53% | 40% | 50% | | 16384 | 53% | 33% | 50% | Note: this update doesn't change the driver performance without DMA. As shown, performance with DMA is slightly lower than without, but in most cases, it will save CPU time. Signed-off-by: Maxime Méré <maxime.mere@foss.st.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.