lib/crypto: mips/sha512: Migrate optimized SHA-512 code to library

Instead of exposing the mips-optimized SHA-512 code via mips-specific
crypto_shash algorithms, instead just implement the sha512_blocks()
library function.  This is much simpler, it makes the SHA-512 (and
SHA-384) library functions be mips-optimized, and it fixes the
longstanding issue where the mips-optimized SHA-512 code was disabled by
default.  SHA-512 still remains available through crypto_shash, but
individual architectures no longer need to handle it.

Note: to see the diff from
arch/mips/cavium-octeon/crypto/octeon-sha512.c to
lib/crypto/mips/sha512.h, view this commit with 'git show -M10'.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250630160320.2888-11-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

2 files changed, 75 insertions, 0 deletions

diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index 26413f679fab..303ea15e3e90 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -179,6 +179,7 @@ config CRYPTO_LIB_SHA512_ARCH
 	depends on CRYPTO_LIB_SHA512 && !UML
 	default y if ARM && !CPU_V7M
 	default y if ARM64
+	default y if MIPS && CPU_CAVIUM_OCTEON
 
 config CRYPTO_LIB_SM3
 	tristate
diff --git a/lib/crypto/mips/sha512.h b/lib/crypto/mips/sha512.h
new file mode 100644
index 000000000000..b3ffbc1e8ca8
--- /dev/null
+++ b/lib/crypto/mips/sha512.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Cryptographic API.
+ *
+ * SHA-512 and SHA-384 Secure Hash Algorithm.
+ *
+ * Adapted for OCTEON by Aaro Koskinen <aaro.koskinen@iki.fi>.
+ *
+ * Based on crypto/sha512_generic.c, which is:
+ *
+ * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
+ * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
+ * Copyright (c) 2003 Kyle McMartin <kyle@debian.org>
+ */
+
+#include <asm/octeon/crypto.h>
+#include <asm/octeon/octeon.h>
+
+/*
+ * We pass everything as 64-bit. OCTEON can handle misaligned data.
+ */
+
+static void sha512_blocks(struct sha512_block_state *state,
+			  const u8 *data, size_t nblocks)
+{
+	struct octeon_cop2_state cop2_state;
+	unsigned long flags;
+
+	if (!octeon_has_crypto())
+		return sha512_blocks_generic(state, data, nblocks);
+
+	flags = octeon_crypto_enable(&cop2_state);
+	write_octeon_64bit_hash_sha512(state->h[0], 0);
+	write_octeon_64bit_hash_sha512(state->h[1], 1);
+	write_octeon_64bit_hash_sha512(state->h[2], 2);
+	write_octeon_64bit_hash_sha512(state->h[3], 3);
+	write_octeon_64bit_hash_sha512(state->h[4], 4);
+	write_octeon_64bit_hash_sha512(state->h[5], 5);
+	write_octeon_64bit_hash_sha512(state->h[6], 6);
+	write_octeon_64bit_hash_sha512(state->h[7], 7);
+
+	do {
+		const u64 *block = (const u64 *)data;
+
+		write_octeon_64bit_block_sha512(block[0], 0);
+		write_octeon_64bit_block_sha512(block[1], 1);
+		write_octeon_64bit_block_sha512(block[2], 2);
+		write_octeon_64bit_block_sha512(block[3], 3);
+		write_octeon_64bit_block_sha512(block[4], 4);
+		write_octeon_64bit_block_sha512(block[5], 5);
+		write_octeon_64bit_block_sha512(block[6], 6);
+		write_octeon_64bit_block_sha512(block[7], 7);
+		write_octeon_64bit_block_sha512(block[8], 8);
+		write_octeon_64bit_block_sha512(block[9], 9);
+		write_octeon_64bit_block_sha512(block[10], 10);
+		write_octeon_64bit_block_sha512(block[11], 11);
+		write_octeon_64bit_block_sha512(block[12], 12);
+		write_octeon_64bit_block_sha512(block[13], 13);
+		write_octeon_64bit_block_sha512(block[14], 14);
+		octeon_sha512_start(block[15]);
+
+		data += SHA512_BLOCK_SIZE;
+	} while (--nblocks);
+
+	state->h[0] = read_octeon_64bit_hash_sha512(0);
+	state->h[1] = read_octeon_64bit_hash_sha512(1);
+	state->h[2] = read_octeon_64bit_hash_sha512(2);
+	state->h[3] = read_octeon_64bit_hash_sha512(3);
+	state->h[4] = read_octeon_64bit_hash_sha512(4);
+	state->h[5] = read_octeon_64bit_hash_sha512(5);
+	state->h[6] = read_octeon_64bit_hash_sha512(6);
+	state->h[7] = read_octeon_64bit_hash_sha512(7);
+	octeon_crypto_disable(&cop2_state, flags);
+}