[S390] crypto: cleanup.

Cleanup code and remove obsolete documentation.

Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/crypto/sha1_s390.c b/arch/s390/crypto/sha1_s390.c
index 969639f..af4460e 100644
--- a/arch/s390/crypto/sha1_s390.c
+++ b/arch/s390/crypto/sha1_s390.c
@@ -25,99 +25,100 @@
  */
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/mm.h>
 #include <linux/crypto.h>
-#include <asm/scatterlist.h>
-#include <asm/byteorder.h>
+
 #include "crypt_s390.h"
 
 #define SHA1_DIGEST_SIZE	20
 #define SHA1_BLOCK_SIZE		64
 
-struct crypt_s390_sha1_ctx {
-	u64 count;
+struct s390_sha1_ctx {
+	u64 count;		/* message length */
 	u32 state[5];
-	u32 buf_len;
-	u8 buffer[2 * SHA1_BLOCK_SIZE];
+	u8 buf[2 * SHA1_BLOCK_SIZE];
 };
 
 static void sha1_init(struct crypto_tfm *tfm)
 {
-	struct crypt_s390_sha1_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
 
-	ctx->state[0] = 0x67452301;
-	ctx->state[1] =	0xEFCDAB89;
-	ctx->state[2] =	0x98BADCFE;
-	ctx->state[3] = 0x10325476;
-	ctx->state[4] =	0xC3D2E1F0;
-
-	ctx->count = 0;
-	ctx->buf_len = 0;
+	sctx->state[0] = 0x67452301;
+	sctx->state[1] = 0xEFCDAB89;
+	sctx->state[2] = 0x98BADCFE;
+	sctx->state[3] = 0x10325476;
+	sctx->state[4] = 0xC3D2E1F0;
+	sctx->count = 0;
 }
 
 static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
 			unsigned int len)
 {
-	struct crypt_s390_sha1_ctx *sctx;
-	long imd_len;
+	struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+	unsigned int index;
+	int ret;
 
-	sctx = crypto_tfm_ctx(tfm);
-	sctx->count += len * 8; /* message bit length */
+	/* how much is already in the buffer? */
+	index = sctx->count & 0x3f;
 
-	/* anything in buffer yet? -> must be completed */
-	if (sctx->buf_len && (sctx->buf_len + len) >= SHA1_BLOCK_SIZE) {
-		/* complete full block and hash */
-		memcpy(sctx->buffer + sctx->buf_len, data,
-		       SHA1_BLOCK_SIZE - sctx->buf_len);
-		crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer,
-				SHA1_BLOCK_SIZE);
-		data += SHA1_BLOCK_SIZE - sctx->buf_len;
-		len -= SHA1_BLOCK_SIZE - sctx->buf_len;
-		sctx->buf_len = 0;
+	sctx->count += len;
+
+	if (index + len < SHA1_BLOCK_SIZE)
+		goto store;
+
+	/* process one stored block */
+	if (index) {
+		memcpy(sctx->buf + index, data, SHA1_BLOCK_SIZE - index);
+		ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf,
+				      SHA1_BLOCK_SIZE);
+		BUG_ON(ret != SHA1_BLOCK_SIZE);
+		data += SHA1_BLOCK_SIZE - index;
+		len -= SHA1_BLOCK_SIZE - index;
 	}
 
-	/* rest of data contains full blocks? */
-	imd_len = len & ~0x3ful;
-	if (imd_len) {
-		crypt_s390_kimd(KIMD_SHA_1, sctx->state, data, imd_len);
-		data += imd_len;
-		len -= imd_len;
+	/* process as many blocks as possible */
+	if (len >= SHA1_BLOCK_SIZE) {
+		ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, data,
+				      len & ~(SHA1_BLOCK_SIZE - 1));
+		BUG_ON(ret != (len & ~(SHA1_BLOCK_SIZE - 1)));
+		data += ret;
+		len -= ret;
 	}
-	/* anything left? store in buffer */
-	if (len) {
-		memcpy(sctx->buffer + sctx->buf_len , data, len);
-		sctx->buf_len += len;
-	}
-}
 
-
-static void pad_message(struct crypt_s390_sha1_ctx* sctx)
-{
-	int index;
-
-	index = sctx->buf_len;
-	sctx->buf_len = (sctx->buf_len < 56) ?
-			 SHA1_BLOCK_SIZE:2 * SHA1_BLOCK_SIZE;
-	/* start pad with 1 */
-	sctx->buffer[index] = 0x80;
-	/* pad with zeros */
-	index++;
-	memset(sctx->buffer + index, 0x00, sctx->buf_len - index);
-	/* append length */
-	memcpy(sctx->buffer + sctx->buf_len - 8, &sctx->count,
-	       sizeof sctx->count);
+store:
+	/* anything left? */
+	if (len)
+		memcpy(sctx->buf + index , data, len);
 }
 
 /* Add padding and return the message digest. */
 static void sha1_final(struct crypto_tfm *tfm, u8 *out)
 {
-	struct crypt_s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+	struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+	u64 bits;
+	unsigned int index, end;
+	int ret;
 
 	/* must perform manual padding */
-	pad_message(sctx);
-	crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer, sctx->buf_len);
+	index = sctx->count & 0x3f;
+	end =  (index < 56) ? SHA1_BLOCK_SIZE : (2 * SHA1_BLOCK_SIZE);
+
+	/* start pad with 1 */
+	sctx->buf[index] = 0x80;
+
+	/* pad with zeros */
+	index++;
+	memset(sctx->buf + index, 0x00, end - index - 8);
+
+	/* append message length */
+	bits = sctx->count * 8;
+	memcpy(sctx->buf + end - 8, &bits, sizeof(bits));
+
+	ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf, end);
+	BUG_ON(ret != end);
+
 	/* copy digest to out */
 	memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
+
 	/* wipe context */
 	memset(sctx, 0, sizeof *sctx);
 }
@@ -128,7 +129,7 @@
 	.cra_priority	=	CRYPT_S390_PRIORITY,
 	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
 	.cra_blocksize	=	SHA1_BLOCK_SIZE,
-	.cra_ctxsize	=	sizeof(struct crypt_s390_sha1_ctx),
+	.cra_ctxsize	=	sizeof(struct s390_sha1_ctx),
 	.cra_module	=	THIS_MODULE,
 	.cra_list	=	LIST_HEAD_INIT(alg.cra_list),
 	.cra_u		=	{ .digest = {