lib/crypto: powerpc/md5: Migrate optimized code into library

Instead of exposing the powerpc-optimized MD5 code via powerpc-specific
crypto_shash algorithms, instead just implement the md5_blocks() library
function. This is much simpler, it makes the MD5 library functions be
powerpc-optimized, and it fixes the longstanding issue where the
powerpc-optimized MD5 code was disabled by default. MD5 still remains
available through crypto_shash, but individual architectures no longer
need to handle it.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Eric Biggers <[e-mail]>

arch/powerpc/configs/powernv_defconfig

···
 CONFIG_CRYPTO_BENCHMARK=m
 CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y
-CONFIG_CRYPTO_MD5_PPC=m
 CONFIG_CRYPTO_MICHAEL_MIC=m
 CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_WP512=m

arch/powerpc/configs/ppc64_defconfig

···
 CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_LZO=m
-CONFIG_CRYPTO_MD5_PPC=m
 CONFIG_CRYPTO_AES_GCM_P10=m
 CONFIG_CRYPTO_DEV_NX=y
 CONFIG_CRYPTO_DEV_NX_ENCRYPT=m

arch/powerpc/crypto/Kconfig

···
 	  Architecture: PowerPC64
 	  - Little-endian
 
-config CRYPTO_MD5_PPC
-	tristate "Digests: MD5"
-	select CRYPTO_HASH
-	help
-	  MD5 message digest algorithm (RFC1321)
-
-	  Architecture: powerpc
-
 config CRYPTO_AES_PPC_SPE
 	tristate "Ciphers: AES, modes: ECB/CBC/CTR/XTS (SPE)"
 	depends on SPE

arch/powerpc/crypto/Makefile

···
 #
 
 obj-$(CONFIG_CRYPTO_AES_PPC_SPE) += aes-ppc-spe.o
-obj-$(CONFIG_CRYPTO_MD5_PPC) += md5-ppc.o
 obj-$(CONFIG_CRYPTO_AES_GCM_P10) += aes-gcm-p10-crypto.o
 obj-$(CONFIG_CRYPTO_DEV_VMX_ENCRYPT) += vmx-crypto.o
 obj-$(CONFIG_CRYPTO_CURVE25519_PPC64) += curve25519-ppc64le.o
 
 aes-ppc-spe-y := aes-spe-core.o aes-spe-keys.o aes-tab-4k.o aes-spe-modes.o aes-spe-glue.o
-md5-ppc-y := md5-asm.o md5-glue.o
 aes-gcm-p10-crypto-y := aes-gcm-p10-glue.o aes-gcm-p10.o ghashp10-ppc.o aesp10-ppc.o
 vmx-crypto-objs := vmx.o aesp8-ppc.o ghashp8-ppc.o aes.o aes_cbc.o aes_ctr.o aes_xts.o ghash.o
 curve25519-ppc64le-y := curve25519-ppc64le-core.o curve25519-ppc64le_asm.o

arch/powerpc/crypto/md5-glue.c

···
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Glue code for MD5 implementation for PPC assembler
- *
- * Based on generic implementation.
- *
- * Copyright (c) 2015 Markus Stockhausen <[e-mail]>
- */
-
-#include <crypto/internal/hash.h>
-#include <crypto/md5.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/string.h>
-
-extern void ppc_md5_transform(u32 *state, const u8 *src, u32 blocks);
-
-static int ppc_md5_init(struct shash_desc *desc)
-{
-	struct md5_state *sctx = shash_desc_ctx(desc);
-
-	sctx->hash[0] = MD5_H0;
-	sctx->hash[1] = MD5_H1;
-	sctx->hash[2] = MD5_H2;
-	sctx->hash[3] =	MD5_H3;
-	sctx->byte_count = 0;
-
-	return 0;
-}
-
-static int ppc_md5_update(struct shash_desc *desc, const u8 *data,
-			unsigned int len)
-{
-	struct md5_state *sctx = shash_desc_ctx(desc);
-
-	sctx->byte_count += round_down(len, MD5_HMAC_BLOCK_SIZE);
-	ppc_md5_transform(sctx->hash, data, len >> 6);
-	return len - round_down(len, MD5_HMAC_BLOCK_SIZE);
-}
-
-static int ppc_md5_finup(struct shash_desc *desc, const u8 *src,
-			 unsigned int offset, u8 *out)
-{
-	struct md5_state *sctx = shash_desc_ctx(desc);
-	__le64 block[MD5_BLOCK_WORDS] = {};
-	u8 *p = memcpy(block, src, offset);
-	__le32 *dst = (__le32 *)out;
-	__le64 *pbits;
-
-	src = p;
-	p += offset;
-	*p++ = 0x80;
-	sctx->byte_count += offset;
-	pbits = &block[(MD5_BLOCK_WORDS / (offset > 55 ? 1 : 2)) - 1];
-	*pbits = cpu_to_le64(sctx->byte_count << 3);
-	ppc_md5_transform(sctx->hash, src, (pbits - block + 1) / 8);
-	memzero_explicit(block, sizeof(block));
-
-	dst[0] = cpu_to_le32(sctx->hash[0]);
-	dst[1] = cpu_to_le32(sctx->hash[1]);
-	dst[2] = cpu_to_le32(sctx->hash[2]);
-	dst[3] = cpu_to_le32(sctx->hash[3]);
-	return 0;
-}
-
-static struct shash_alg alg = {
-	.digestsize	=	MD5_DIGEST_SIZE,
-	.init		=	ppc_md5_init,
-	.update		=	ppc_md5_update,
-	.finup		=	ppc_md5_finup,
-	.descsize	=	MD5_STATE_SIZE,
-	.base		=	{
-		.cra_name	=	"md5",
-		.cra_driver_name=	"md5-ppc",
-		.cra_priority	=	200,
-		.cra_flags	=	CRYPTO_AHASH_ALG_BLOCK_ONLY,
-		.cra_blocksize	=	MD5_HMAC_BLOCK_SIZE,
-		.cra_module	=	THIS_MODULE,
-	}
-};
-
-static int __init ppc_md5_mod_init(void)
-{
-	return crypto_register_shash(&alg);
-}
-
-static void __exit ppc_md5_mod_fini(void)
-{
-	crypto_unregister_shash(&alg);
-}
-
-module_init(ppc_md5_mod_init);
-module_exit(ppc_md5_mod_fini);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("MD5 Secure Hash Algorithm, PPC assembler");
-
-MODULE_ALIAS_CRYPTO("md5");
-MODULE_ALIAS_CRYPTO("md5-ppc");

lib/crypto/Kconfig

···
 	bool
 	depends on CRYPTO_LIB_MD5 && !UML
 	default y if MIPS && CPU_CAVIUM_OCTEON
+	default y if PPC
 
 config CRYPTO_LIB_POLY1305_RSIZE
 	int

lib/crypto/Makefile

···
 libmd5-y := md5.o
 ifeq ($(CONFIG_CRYPTO_LIB_MD5_ARCH),y)
 CFLAGS_md5.o += -I$(src)/$(SRCARCH)
+libmd5-$(CONFIG_PPC) += powerpc/md5-asm.o
 endif # CONFIG_CRYPTO_LIB_MD5_ARCH
 
 ################################################################################

lib/crypto/powerpc/md5.h

···
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * MD5 optimized for PowerPC
+ */
+
+void ppc_md5_transform(u32 *state, const u8 *data, size_t nblocks);
+
+static void md5_blocks(struct md5_block_state *state,
+		       const u8 *data, size_t nblocks)
+{
+	ppc_md5_transform(state->h, data, nblocks);
+}