lib/crypto: riscv/ghash: Migrate optimized code into library

Remove the "ghash-riscv64-zvkg" crypto_shash algorithm.  Move the
corresponding assembly code into lib/crypto/, modify it to take the
length in blocks instead of bytes, and wire it up to the GHASH library.

This makes the GHASH library be optimized with the RISC-V Vector
Cryptography Extension.  It also greatly reduces the amount of
riscv-specific glue code that is needed, and it fixes the issue where
this optimized GHASH code was disabled by default.

Note that this RISC-V code has multiple opportunities for improvement,
such as adding more parallelism, providing an optimized multiplication
function, and directly supporting POLYVAL.  But for now, this commit
simply tweaks ghash_zvkg() slightly to make it compatible with the
library, then wires it up to ghash_blocks_arch().

ghash_preparekey_arch() is also implemented to store the copy of the raw
key needed by the vghsh.vv instruction.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260319061723.1140720-13-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index 8a9084188778..8950509833af 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -173,6 +173,7 @@ targets += powerpc/ghashp8-ppc.S
 OBJECT_FILES_NON_STANDARD_powerpc/ghashp8-ppc.o := y
 endif
 
+libgf128hash-$(CONFIG_RISCV) += riscv/ghash-riscv64-zvkg.o
 libgf128hash-$(CONFIG_X86) += x86/polyval-pclmul-avx.o
 endif # CONFIG_CRYPTO_LIB_GF128HASH_ARCH