crypto: crct10dif - expose arch-optimized lib function

Now that crc_t10dif_update() may be directly optimized for each
architecture, make the shash driver for crct10dif register a
crct10dif-$arch algorithm that uses it, instead of only
crct10dif-generic which uses crc_t10dif_generic().

The result is that architecture-optimized crct10dif will remain
available through the shash API once the architectures implement
crc_t10dif_arch() instead of the shash API.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241202012056.209768-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

crypto/Makefile

@@ -158,6 +158,7 @@ obj-$(CONFIG_CRYPTO_CRC32) += crc32_generic.o
 CFLAGS_crc32c_generic.o += -DARCH=$(ARCH)
 CFLAGS_crc32_generic.o += -DARCH=$(ARCH)
 obj-$(CONFIG_CRYPTO_CRCT10DIF) += crct10dif_generic.o
+CFLAGS_crct10dif_generic.o += -DARCH=$(ARCH)
 obj-$(CONFIG_CRYPTO_CRC64_ROCKSOFT) += crc64_rocksoft_generic.o
 obj-$(CONFIG_CRYPTO_AUTHENC) += authenc.o authencesn.o
 obj-$(CONFIG_CRYPTO_LZO) += lzo.o lzo-rle.o

crypto/crct10dif_generic.c

@@ -57,6 +57,15 @@ static int chksum_update(struct shash_desc *desc, const u8 *data,
 	return 0;
 }
 
+static int chksum_update_arch(struct shash_desc *desc, const u8 *data,
+			      unsigned int length)
+{
+	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+	ctx->crc = crc_t10dif_update(ctx->crc, data, length);
+	return 0;
+}
+
 static int chksum_final(struct shash_desc *desc, u8 *out)
 {
 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
@@ -71,6 +80,13 @@ static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)
 	return 0;
 }
 
+static int __chksum_finup_arch(__u16 crc, const u8 *data, unsigned int len,
+			       u8 *out)
+{
+	*(__u16 *)out = crc_t10dif_update(crc, data, len);
+	return 0;
+}
+
 static int chksum_finup(struct shash_desc *desc, const u8 *data,
 			unsigned int len, u8 *out)
 {
@@ -79,37 +95,67 @@ static int chksum_finup(struct shash_desc *desc, const u8 *data,
 	return __chksum_finup(ctx->crc, data, len, out);
 }
 
+static int chksum_finup_arch(struct shash_desc *desc, const u8 *data,
+			     unsigned int len, u8 *out)
+{
+	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+	return __chksum_finup_arch(ctx->crc, data, len, out);
+}
+
 static int chksum_digest(struct shash_desc *desc, const u8 *data,
 			 unsigned int length, u8 *out)
 {
 	return __chksum_finup(0, data, length, out);
 }
 
-static struct shash_alg alg = {
-	.digestsize		=	CRC_T10DIF_DIGEST_SIZE,
-	.init		=	chksum_init,
-	.update		=	chksum_update,
-	.final		=	chksum_final,
-	.finup		=	chksum_finup,
-	.digest		=	chksum_digest,
-	.descsize		=	sizeof(struct chksum_desc_ctx),
-	.base			=	{
-		.cra_name		=	"crct10dif",
-		.cra_driver_name	=	"crct10dif-generic",
-		.cra_priority		=	100,
-		.cra_blocksize		=	CRC_T10DIF_BLOCK_SIZE,
-		.cra_module		=	THIS_MODULE,
-	}
-};
+static int chksum_digest_arch(struct shash_desc *desc, const u8 *data,
+			      unsigned int length, u8 *out)
+{
+	return __chksum_finup_arch(0, data, length, out);
+}
+
+static struct shash_alg algs[] = {{
+	.digestsize		= CRC_T10DIF_DIGEST_SIZE,
+	.init			= chksum_init,
+	.update			= chksum_update,
+	.final			= chksum_final,
+	.finup			= chksum_finup,
+	.digest			= chksum_digest,
+	.descsize		= sizeof(struct chksum_desc_ctx),
+	.base.cra_name		= "crct10dif",
+	.base.cra_driver_name	= "crct10dif-generic",
+	.base.cra_priority	= 100,
+	.base.cra_blocksize	= CRC_T10DIF_BLOCK_SIZE,
+	.base.cra_module	= THIS_MODULE,
+}, {
+	.digestsize		= CRC_T10DIF_DIGEST_SIZE,
+	.init			= chksum_init,
+	.update			= chksum_update_arch,
+	.final			= chksum_final,
+	.finup			= chksum_finup_arch,
+	.digest			= chksum_digest_arch,
+	.descsize		= sizeof(struct chksum_desc_ctx),
+	.base.cra_name		= "crct10dif",
+	.base.cra_driver_name	= "crct10dif-" __stringify(ARCH),
+	.base.cra_priority	= 150,
+	.base.cra_blocksize	= CRC_T10DIF_BLOCK_SIZE,
+	.base.cra_module	= THIS_MODULE,
+}};
+
+static int num_algs;
 
 static int __init crct10dif_mod_init(void)
 {
-	return crypto_register_shash(&alg);
+	/* register the arch flavor only if it differs from the generic one */
+	num_algs = 1 + crc_t10dif_is_optimized();
+
+	return crypto_register_shashes(algs, num_algs);
 }
 
 static void __exit crct10dif_mod_fini(void)
 {
-	crypto_unregister_shash(&alg);
+	crypto_unregister_shashes(algs, num_algs);
 }
 
 subsys_initcall(crct10dif_mod_init);