crypto: s390 - add System z hardware support for GHASH

This patch adds System z hardware acceleration support for the GHASH
algorithm for GCM (Galois/Counter Mode).
The hardware support is available beginning with System z196.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/s390/crypto/Makefile b/arch/s390/crypto/Makefile
index 1cf81d7..7f0b7cd 100644 (file)
--- a/arch/s390/crypto/Makefile
+++ b/arch/s390/crypto/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_CRYPTO_SHA512_S390) += sha512_s390.o sha_common.o
 obj-$(CONFIG_CRYPTO_DES_S390) += des_s390.o
 obj-$(CONFIG_CRYPTO_AES_S390) += aes_s390.o
 obj-$(CONFIG_S390_PRNG) += prng.o
+obj-$(CONFIG_CRYPTO_GHASH_S390) += ghash_s390.o

diff --git a/arch/s390/crypto/crypt_s390.h b/arch/s390/crypto/crypt_s390.h
index 7cbfaf0..eb2e391 100644 (file)
--- a/arch/s390/crypto/crypt_s390.h
+++ b/arch/s390/crypto/crypt_s390.h
@@ -91,6 +91,7 @@ enum crypt_s390_kimd_func {
        KIMD_SHA_1   = CRYPT_S390_KIMD | 1,
        KIMD_SHA_256 = CRYPT_S390_KIMD | 2,
        KIMD_SHA_512 = CRYPT_S390_KIMD | 3,
+       KIMD_GHASH   = CRYPT_S390_KIMD | 65,
 };
 
 /*

diff --git a/arch/s390/crypto/ghash_s390.c b/arch/s390/crypto/ghash_s390.c
new file mode 100644 (file)
index 0000000..b1bd170
--- /dev/null
+++ b/arch/s390/crypto/ghash_s390.c
@@ -0,0 +1,162 @@
+/*
+ * 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 "crypt_s390.h"
+
+#define GHASH_BLOCK_SIZE       16
+#define GHASH_DIGEST_SIZE      16
+
+struct ghash_ctx {
+       u8 icv[16];
+       u8 key[16];
+};
+
+struct ghash_desc_ctx {
+       u8 buffer[GHASH_BLOCK_SIZE];
+       u32 bytes;
+};
+
+static int ghash_init(struct shash_desc *desc)
+{
+       struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+
+       memset(dctx, 0, sizeof(*dctx));
+
+       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) {
+               crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+               return -EINVAL;
+       }
+
+       memcpy(ctx->key, key, GHASH_BLOCK_SIZE);
+       memset(ctx->icv, 0, 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);
+       struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
+       unsigned int n;
+       u8 *buf = dctx->buffer;
+       int ret;
+
+       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) {
+                       ret = crypt_s390_kimd(KIMD_GHASH, ctx, buf,
+                                             GHASH_BLOCK_SIZE);
+                       BUG_ON(ret != GHASH_BLOCK_SIZE);
+               }
+       }
+
+       n = srclen & ~(GHASH_BLOCK_SIZE - 1);
+       if (n) {
+               ret = crypt_s390_kimd(KIMD_GHASH, ctx, src, n);
+               BUG_ON(ret != n);
+               src += n;
+               srclen -= n;
+       }
+
+       if (srclen) {
+               dctx->bytes = GHASH_BLOCK_SIZE - srclen;
+               memcpy(buf, src, srclen);
+       }
+
+       return 0;
+}
+
+static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
+{
+       u8 *buf = dctx->buffer;
+       int ret;
+
+       if (dctx->bytes) {
+               u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
+
+               memset(pos, 0, dctx->bytes);
+
+               ret = crypt_s390_kimd(KIMD_GHASH, ctx, buf, GHASH_BLOCK_SIZE);
+               BUG_ON(ret != GHASH_BLOCK_SIZE);
+       }
+
+       dctx->bytes = 0;
+}
+
+static int ghash_final(struct shash_desc *desc, u8 *dst)
+{
+       struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+       struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
+
+       ghash_flush(ctx, dctx);
+       memcpy(dst, ctx->icv, GHASH_BLOCK_SIZE);
+
+       return 0;
+}
+
+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           = CRYPT_S390_PRIORITY,
+               .cra_flags              = CRYPTO_ALG_TYPE_SHASH,
+               .cra_blocksize          = GHASH_BLOCK_SIZE,
+               .cra_ctxsize            = sizeof(struct ghash_ctx),
+               .cra_module             = THIS_MODULE,
+               .cra_list               = LIST_HEAD_INIT(ghash_alg.base.cra_list),
+       },
+};
+
+static int __init ghash_mod_init(void)
+{
+       if (!crypt_s390_func_available(KIMD_GHASH,
+                                      CRYPT_S390_MSA | CRYPT_S390_MSA4))
+               return -EOPNOTSUPP;
+
+       return crypto_register_shash(&ghash_alg);
+}
+
+static void __exit ghash_mod_exit(void)
+{
+       crypto_unregister_shash(&ghash_alg);
+}
+
+module_init(ghash_mod_init);
+module_exit(ghash_mod_exit);
+
+MODULE_ALIAS("ghash");
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("GHASH Message Digest Algorithm, s390 implementation");

diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 78df36a..d459cc7 100644 (file)
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -151,6 +151,16 @@ config S390_PRNG
          ANSI X9.17 standard. The PRNG is usable via the char device
          /dev/prandom.
 
+config CRYPTO_GHASH_S390
+       tristate "GHASH digest algorithm"
+       depends on S390
+       select CRYPTO_HASH
+       help
+         This is the s390 hardware accelerated implementation of the
+         GHASH message digest algorithm for GCM (Galois/Counter Mode).
+
+         It is available as of z196.
+
 config CRYPTO_DEV_MV_CESA
        tristate "Marvell's Cryptographic Engine"
        depends on PLAT_ORION