lib/crypto: sparc/sha1: Migrate optimized code into library

Instead of exposing the sparc-optimized SHA-1 code via sparc-specific
crypto_shash algorithms, instead just implement the sha1_blocks()
library function.  This is much simpler, it makes the SHA-1 library
functions be sparc-optimized, and it fixes the longstanding issue where
the sparc-optimized SHA-1 code was disabled by default.  SHA-1 still
remains available through crypto_shash, but individual architectures no
longer need to handle it.

Note: to see the diff from arch/sparc/crypto/sha1_glue.c to
lib/crypto/sparc/sha1.h, view this commit with 'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250712232329.818226-13-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

Author: Eric Biggers

arch/sparc/crypto/Kconfig

@@ -26,16 +26,6 @@ config CRYPTO_MD5_SPARC64
 
 	  Architecture: sparc64 using crypto instructions, when available
 
-config CRYPTO_SHA1_SPARC64
-	tristate "Hash functions: SHA-1"
-	depends on SPARC64
-	select CRYPTO_SHA1
-	select CRYPTO_HASH
-	help
-	  SHA-1 secure hash algorithm (FIPS 180)
-
-	  Architecture: sparc64
-
 config CRYPTO_AES_SPARC64
 	tristate "Ciphers: AES, modes: ECB, CBC, CTR"
 	depends on SPARC64

arch/sparc/crypto/Makefile

@@ -3,14 +3,12 @@
 # Arch-specific CryptoAPI modules.
 #
 
-obj-$(CONFIG_CRYPTO_SHA1_SPARC64) += sha1-sparc64.o
 obj-$(CONFIG_CRYPTO_MD5_SPARC64) += md5-sparc64.o
 
 obj-$(CONFIG_CRYPTO_AES_SPARC64) += aes-sparc64.o
 obj-$(CONFIG_CRYPTO_DES_SPARC64) += des-sparc64.o
 obj-$(CONFIG_CRYPTO_CAMELLIA_SPARC64) += camellia-sparc64.o
 
-sha1-sparc64-y := sha1_asm.o sha1_glue.o
 md5-sparc64-y := md5_asm.o md5_glue.o
 
 aes-sparc64-y := aes_asm.o aes_glue.o

arch/sparc/crypto/sha1_glue.c

@@ -151,6 +151,7 @@ config CRYPTO_LIB_SHA1_ARCH
 	default y if MIPS && CPU_CAVIUM_OCTEON
 	default y if PPC
 	default y if S390
+	default y if SPARC64
 
 config CRYPTO_LIB_SHA256
 	tristate

lib/crypto/Kconfig

@@ -81,6 +81,7 @@ ifeq ($(CONFIG_PPC),y)
 libsha1-y += powerpc/sha1-powerpc-asm.o
 libsha1-$(CONFIG_SPE) += powerpc/sha1-spe-asm.o
 endif
+libsha1-$(CONFIG_SPARC) += sparc/sha1_asm.o
 endif # CONFIG_CRYPTO_LIB_SHA1_ARCH
 
 ################################################################################

lib/crypto/Makefile

@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * SHA-1 accelerated using the sparc64 crypto opcodes
+ *
+ * Copyright (c) Alan Smithee.
+ * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
+ * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
+ * Copyright (c) Mathias Krause <minipli@googlemail.com>
+ */
+
+#include <asm/elf.h>
+#include <asm/opcodes.h>
+#include <asm/pstate.h>
+
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_sha1_opcodes);
+
+asmlinkage void sha1_sparc64_transform(struct sha1_block_state *state,
+				       const u8 *data, size_t nblocks);
+
+static void sha1_blocks(struct sha1_block_state *state,
+			const u8 *data, size_t nblocks)
+{
+	if (static_branch_likely(&have_sha1_opcodes))
+		sha1_sparc64_transform(state, data, nblocks);
+	else
+		sha1_blocks_generic(state, data, nblocks);
+}
+
+#define sha1_mod_init_arch sha1_mod_init_arch
+static inline void sha1_mod_init_arch(void)
+{
+	unsigned long cfr;
+
+	if (!(sparc64_elf_hwcap & HWCAP_SPARC_CRYPTO))
+		return;
+
+	__asm__ __volatile__("rd %%asr26, %0" : "=r" (cfr));
+	if (!(cfr & CFR_SHA1))
+		return;
+
+	static_branch_enable(&have_sha1_opcodes);
+	pr_info("Using sparc64 sha1 opcode optimized SHA-1 implementation\n");
+}