New s390 specific protected key hmac

Add support for protected key hmac ("phmac") for s390 arch.

With the latest machine generation there is now support for protected key (that is a key wrapped by a master key stored in firmware) hmac for sha2 (sha224, sha256, sha384 and sha512) for the s390 specific CPACF instruction kmac.

This patch adds support via 4 new hashes registered as phmac(sha224), phmac(sha256), phmac(sha384) and phmac(sha512).

Changelog:
v1: Initial version
v2: Increase HASH_MAX_DESCSIZE generic (not just for arch s390).
Fix one finding to use kmemdup instead of kmalloc/memcpy from test robot. Remove unneeded cpacf subfunctions checks. Simplify clone_tfm() function. Rebased to s390/features.
v3: Feedback from Herbert: Use GFP_ATOMIC in setkey function.
Feedback from Holger: rework tfm clone function, move convert key invocation from setkey to init function. Rebased to updated s390/features from 11/7/2024. Ready for integration if there are no complains on v3.
v4: Rewind back more or less to v2. Add code to check for non-sleeping
context. Non-sleeping context during attempt to derive the protected key from raw key material is not accepted and -EOPNOTSUPP is returned (also currently all derivation pathes would in fact never sleep). In general the phmac implementation is not to be used within non-sleeping context and the code header mentions this. Tested with (patched) dm-integrity - works fine.
v5: As suggested by Herbert now the shashes have been marked as
'internal' and wrapped by ahashes which use the cryptd if an atomic context is detected. So the visible phmac algorithms are now ahashes. Unfortunately the dm-integrity implementation currently requests and deals only with shashes and this phmac implementation is not fitting to the original goal any more...
v6: As suggested by Herbert now a pure async phmac implementation.
Tested via AF_ALG interface. Untested via dm-integrity as this layer only supports shashes. Maybe I'll develop a patch to switch the dm-integrity to ahash as it is anyway the more flexible interface.
v7: Total rework of the implementation. Now uses workqueues and triggers
asynch requests for key convert, init, update, final and digest. Tested with instrumented code and with a reworked version of dm-integrity which uses asynchronous hashes. A patch for dm-integrity is on the way but yet needs some last hone work.
v8: Added selftest. With the selftest comes some code which wraps the
clear key into a "clear key token" digestible by PKEY. The selftest also uses import() and export(), so these are now also implemented. Furthermore a finup() implementation is now also available. Tested with AF_ALG testcases and dm-integrity, also tested with some instrumented code to check that the asynch workqueue functions do their job correctly. Coding is complete!
v9: As suggested by Herbert use ahash_request_complete() and surround it
with local_bh_disable().
v10: Split the pkey selftest patch into 3 patches. Slight rework of the
setkey function as suggested by Holger: When selftest is running as much as possible of the production code should run. So now the key prep with selftest is one additional if/then block instead of an if/then/else construct.
Code is ready for integration and well tested.
v11: Utterly rework with the insights collected with the paes rework
and the basic work done with the pkey rework over the last 5 month. Note that patch #1 effectively reverts commit 7fa481734016 ("crypto: ahash - make hash walk functions private to ahash.c") from Eric Biggers.
v12: Fixed some typos, adaptions to 128 bit total counter,
misc_register() invocation was missing in the patches series, added Herbert's proposal for a new function crypto_ahash_tested().

Harald Freudenberger (5):
crypto: ahash - make hash walk functions from ahash.c public s390/crypto: New s390 specific protected key hash phmac
crypto: api - Add crypto_ahash_tested() helper function s390/crypto: Add selftest support for phmac
crypto: testmgr - Enable phmac selftest

Holger Dengler (1):
s390/crypto: Add protected key hmac subfunctions for KMAC

 arch/s390/configs/debug_defconfig |    1 +
 arch/s390/configs/defconfig       |    1 +
 arch/s390/crypto/Makefile         |    1 +
 arch/s390/crypto/phmac_s390.c     | 1048 +++++++++++++++++++++++++++++
 arch/s390/include/asm/cpacf.h     |    4 +
 crypto/ahash.c                    |   26 +-
 crypto/testmgr.c                  |   30 +
 drivers/crypto/Kconfig            |   13 +
 include/crypto/internal/hash.h    |   30 +
 9 files changed, 1133 insertions(+), 21 deletions(-)
 create mode 100644 arch/s390/crypto/phmac_s390.c

base-commit: 1029436218e50168812dbc44b16bca6d35721b0b --
2.43.0