crypto: add rocksoft 64b crc guard tag framework

Hardware specific features may be able to calculate a crc64, so provide
a framework for drivers to register their implementation. If nothing is
registered, fallback to the generic table lookup implementation. The
implementation is modeled after the crct10dif equivalent.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20220303201312.3255347-7-kbusch@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 89 insertions, 0 deletions

diff --git a/crypto/crc64_rocksoft_generic.c b/crypto/crc64_rocksoft_generic.c
new file mode 100644
index 000000000000..9e812bb26dba
--- /dev/null
+++ b/crypto/crc64_rocksoft_generic.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/crc64.h>
+#include <linux/module.h>
+#include <crypto/internal/hash.h>
+#include <asm/unaligned.h>
+
+static int chksum_init(struct shash_desc *desc)
+{
+	u64 *crc = shash_desc_ctx(desc);
+
+	*crc = 0;
+
+	return 0;
+}
+
+static int chksum_update(struct shash_desc *desc, const u8 *data,
+			 unsigned int length)
+{
+	u64 *crc = shash_desc_ctx(desc);
+
+	*crc = crc64_rocksoft_generic(*crc, data, length);
+
+	return 0;
+}
+
+static int chksum_final(struct shash_desc *desc, u8 *out)
+{
+	u64 *crc = shash_desc_ctx(desc);
+
+	put_unaligned_le64(*crc, out);
+	return 0;
+}
+
+static int __chksum_finup(u64 crc, const u8 *data, unsigned int len, u8 *out)
+{
+	crc = crc64_rocksoft_generic(crc, data, len);
+	put_unaligned_le64(crc, out);
+	return 0;
+}
+
+static int chksum_finup(struct shash_desc *desc, const u8 *data,
+			unsigned int len, u8 *out)
+{
+	u64 *crc = shash_desc_ctx(desc);
+
+	return __chksum_finup(*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	= 	sizeof(u64),
+	.init		=	chksum_init,
+	.update		=	chksum_update,
+	.final		=	chksum_final,
+	.finup		=	chksum_finup,
+	.digest		=	chksum_digest,
+	.descsize	=	sizeof(u64),
+	.base		=	{
+		.cra_name		=	CRC64_ROCKSOFT_STRING,
+		.cra_driver_name	=	"crc64-rocksoft-generic",
+		.cra_priority		=	200,
+		.cra_blocksize		=	1,
+		.cra_module		=	THIS_MODULE,
+	}
+};
+
+static int __init crc64_rocksoft_init(void)
+{
+	return crypto_register_shash(&alg);
+}
+
+static void __exit crc64_rocksoft_exit(void)
+{
+	crypto_unregister_shash(&alg);
+}
+
+module_init(crc64_rocksoft_init);
+module_exit(crc64_rocksoft_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Rocksoft model CRC64 calculation.");
+MODULE_ALIAS_CRYPTO("crc64-rocksoft");
+MODULE_ALIAS_CRYPTO("crc64-rocksoft-generic");