2f1f34c1bf
The "ahash" API provides access to both CPU-based and hardware offload- based implementations of hash algorithms. Typically the former are implemented as "shash" algorithms under the hood, while the latter are implemented as "ahash" algorithms. The "ahash" API provides access to both. Various kernel subsystems use the ahash API because they want to support hashing hardware offload without using a separate API for it. Yet, the common case is that a crypto accelerator is not actually being used, and ahash is just wrapping a CPU-based shash algorithm. This patch optimizes the ahash API for that common case by eliminating the extra indirect call for each ahash operation on top of shash. It also fixes the double-counting of crypto stats in this scenario (though CONFIG_CRYPTO_STATS should *not* be enabled by anyone interested in performance anyway...), and it eliminates redundant checking of CRYPTO_TFM_NEED_KEY. As a bonus, it also shrinks struct crypto_ahash. Signed-off-by: Eric Biggers <ebiggers@google.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 Restructured Text 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.