1 files changed, 154 insertions, 0 deletions
diff --git a/arch/s390/crypto/ghash_s390.c b/arch/s390/crypto/ghash_s390.c
new file mode 100644
index 000000000..0800a2a57
--- /dev/null
+++ b/arch/s390/crypto/ghash_s390.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cryptographic API.
+ *
+ * s390 implementation of the GHASH algorithm for GCM (Galois/Counter Mode).
+ *
+ * Copyright IBM Corp. 2011
+ * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
+ */
+
+#include <crypto/internal/hash.h>
+#include <linux/module.h>
+#include <linux/cpufeature.h>
+#include <asm/cpacf.h>
+
+#define GHASH_BLOCK_SIZE	16
+#define GHASH_DIGEST_SIZE	16
+
+struct ghash_ctx {
+	u8 key[GHASH_BLOCK_SIZE];
+};
+
+struct ghash_desc_ctx {
+	u8 icv[GHASH_BLOCK_SIZE];
+	u8 key[GHASH_BLOCK_SIZE];
+	u8 buffer[GHASH_BLOCK_SIZE];
+	u32 bytes;
+};
+
+static int ghash_init(struct shash_desc *desc)
+{
+	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
+
+	memset(dctx, 0, sizeof(*dctx));
+	memcpy(dctx->key, ctx->key, GHASH_BLOCK_SIZE);
+
+	return 0;
+}
+
+static int ghash_setkey(struct crypto_shash *tfm,
+			const u8 *key, unsigned int keylen)
+{
+	struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
+
+	if (keylen != GHASH_BLOCK_SIZE)
+		return -EINVAL;
+
+	memcpy(ctx->key, key, GHASH_BLOCK_SIZE);
+
+	return 0;
+}
+
+static int ghash_update(struct shash_desc *desc,
+			 const u8 *src, unsigned int srclen)
+{
+	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+	unsigned int n;
+	u8 *buf = dctx->buffer;
+
+	if (dctx->bytes) {
+		u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
+
+		n = min(srclen, dctx->bytes);
+		dctx->bytes -= n;
+		srclen -= n;
+
+		memcpy(pos, src, n);
+		src += n;
+
+		if (!dctx->bytes) {
+			cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf,
+				   GHASH_BLOCK_SIZE);
+		}
+	}
+
+	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
+	if (n) {
+		cpacf_kimd(CPACF_KIMD_GHASH, dctx, src, n);
+		src += n;
+		srclen -= n;
+	}
+
+	if (srclen) {
+		dctx->bytes = GHASH_BLOCK_SIZE - srclen;
+		memcpy(buf, src, srclen);
+	}
+
+	return 0;
+}
+
+static int ghash_flush(struct ghash_desc_ctx *dctx)
+{
+	u8 *buf = dctx->buffer;
+
+	if (dctx->bytes) {
+		u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
+
+		memset(pos, 0, dctx->bytes);
+		cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf, GHASH_BLOCK_SIZE);
+		dctx->bytes = 0;
+	}
+
+	return 0;
+}
+
+static int ghash_final(struct shash_desc *desc, u8 *dst)
+{
+	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+	int ret;
+
+	ret = ghash_flush(dctx);
+	if (!ret)
+		memcpy(dst, dctx->icv, GHASH_BLOCK_SIZE);
+	return ret;
+}
+
+static struct shash_alg ghash_alg = {
+	.digestsize	= GHASH_DIGEST_SIZE,
+	.init		= ghash_init,
+	.update		= ghash_update,
+	.final		= ghash_final,
+	.setkey		= ghash_setkey,
+	.descsize	= sizeof(struct ghash_desc_ctx),
+	.base		= {
+		.cra_name		= "ghash",
+		.cra_driver_name	= "ghash-s390",
+		.cra_priority		= 300,
+		.cra_blocksize		= GHASH_BLOCK_SIZE,
+		.cra_ctxsize		= sizeof(struct ghash_ctx),
+		.cra_module		= THIS_MODULE,
+	},
+};
+
+static int __init ghash_mod_init(void)
+{
+	if (!cpacf_query_func(CPACF_KIMD, CPACF_KIMD_GHASH))
+		return -ENODEV;
+
+	return crypto_register_shash(&ghash_alg);
+}
+
+static void __exit ghash_mod_exit(void)
+{
+	crypto_unregister_shash(&ghash_alg);
+}
+
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, ghash_mod_init);
+module_exit(ghash_mod_exit);
+
+MODULE_ALIAS_CRYPTO("ghash");
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("GHASH hash function, s390 implementation");