lib/crypto: sparc/aes-xts: Add optimization using the AES opcodes

Implement aes_xts_encrypt_arch() and aes_xts_decrypt_arch() with the AES
opcodes, for AES-128 and AES-256, two blocks per iteration. AES-192,
which IEEE 1619 does not specify, and data that is not 8-byte aligned
are left to the generic code.

The tweak is kept as little-endian words, so that multiplying it by x is
a 128-bit shift done with addcc and the VIS3 addxc. A little-endian
store and an ordinary load through a stack slot give it in the byte
order of the data, and the slot is cleared on return. The routines open
a register window, as %g4-%g6 belong to the kernel.

With that, xts-aes-lib no longer has to be kept off SPARC. Register it
there again, with the priority x86 and RISC-V use, so that it also
outranks an xts(ecb-aes-sparc64) instance (priority 300).

On a T7-1 (M7), MiB/s unless noted:

                               xts(ecb-aes-sparc64)  xts-aes-lib
  AF_ALG, 64 KiB, AES-128                     415         1092
  AF_ALG, 64 KiB, AES-256                     390          936
  dm-crypt on brd, AES-256:
    sequential read                          1399         2559
    sequential write                         1472         3480
    4 KiB write latency, QD1 (us)            40.6         32.7

dm-crypt now matches aes-cbc-essiv on the same ramdisk.

On a T4-1, AF_ALG AES-256 goes from 238 to 544 MiB/s, and AES-128
from 252 to 616.

Tested with CONFIG_CRYPTO_SELFTESTS_FULL, and against OpenSSL over
random keys, tweaks and lengths, on both machines.

Link: https://github.com/sparclinux/issues/issues/106
Signed-off-by: Stian Halseth <stian@itx.no>
Link: https://patch.msgid.link/20261004192812.4145406-1-stian@itx.no
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

0 files changed, 0 insertions, 0 deletions