[PATCH 0/6] net/crypto: Introduce crypto_pool

[Dmitry Safonov <dima@arista.com>]

Add crypto_pool - an API for allocating per-CPU array of crypto requests
on slow-path (in sleep'able context) and to use them on a fast-path,
which is RX/TX for net/ users (or in any other bh-disabled users).
The design is based on the current implementations of md5sig_pool.

Previously, I've suggested to add such API on TCP-AO patch submission [1], 
where Herbert kindly suggested to help with introducing new crypto API.

New API will allow:
- to reuse per-CPU ahash_request(s) for different users
- to allocate only one per-CPU scratch buffer rather than a new one for
  each user
- to have a common API for net/ users that need ahash on RX/TX fast path

In this version I've wired up TCP-MD5 and IPv6-SR-HMAC as users.
Potentially, xfrm_ipcomp and xfrm_ah can be converted as well.
The initial reason for patches would be to have TCP-AO as a user, which
would let it share per-CPU crypto_request for any supported hashing
algorithm.

While at it, I've also made TCP-MD5 static key dynamically switchable.
This means that after TCP-MD5 was used and the last key got destroyed,
the static branch is disabled and any potential penalty for checking
tcp_md5sig_info is gone, and the system's tcp performance should be as
if it never had TCP-MD5 key defined.

[1]: http://lkml.kernel.org/r/20211106034334.GA18577@gondor.apana.org.au

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Francesco Ruggeri <fruggeri@arista.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Leonard Crestez <cdleonard@gmail.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Salam Noureddine <noureddine@arista.com>
Cc: netdev@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Dmitry Safonov (6):
  crypto: Introduce crypto_pool
  crypto_pool: Add crypto_pool_reserve_scratch()
  net/tcp: Separate tcp_md5sig_info allocation into
    tcp_md5sig_info_add()
  net/tcp: Disable TCP-MD5 static key on tcp_md5sig_info destruction
  net/tcp: Use crypto_pool for TCP-MD5
  net/ipv6: sr: Switch to using crypto_pool

 crypto/Kconfig           |  12 ++
 crypto/Makefile          |   1 +
 crypto/crypto_pool.c     | 316 +++++++++++++++++++++++++++++++++++++++
 include/crypto/pool.h    |  33 ++++
 include/net/seg6_hmac.h  |   7 -
 include/net/tcp.h        |  32 ++--
 net/ipv4/Kconfig         |   2 +-
 net/ipv4/tcp.c           | 102 ++++---------
 net/ipv4/tcp_ipv4.c      | 153 ++++++++++++-------
 net/ipv4/tcp_minisocks.c |  23 ++-
 net/ipv4/tcp_output.c    |   4 +-
 net/ipv6/Kconfig         |   2 +-
 net/ipv6/seg6.c          |   3 -
 net/ipv6/seg6_hmac.c     | 204 ++++++++++---------------
 net/ipv6/tcp_ipv6.c      |  63 ++++----
 15 files changed, 634 insertions(+), 323 deletions(-)
 create mode 100644 crypto/crypto_pool.c
 create mode 100644 include/crypto/pool.h


base-commit: 058affafc65a74cf54499fb578b66ad0b18f939b
-- 
2.36.1