crypto: arm/sha2-ce - move SHA-224/256 ARMv8 implementation to base layer

This removes all the boilerplate from the existing implementation,
and replaces it with calls into the base layer.

Signed-off-by: Ard Biesheuvel <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

arch/arm/crypto/Kconfig

···
 config CRYPTO_SHA2_ARM_CE
 	tristate "SHA-224/256 digest algorithm (ARM v8 Crypto Extensions)"
 	depends on KERNEL_MODE_NEON
-	select CRYPTO_SHA256
+	select CRYPTO_SHA256_ARM
 	select CRYPTO_HASH
 	help
 	  SHA-256 secure hash standard (DFIPS 180-2) implemented

arch/arm/crypto/sha2-ce-core.S

···
 	.word		0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 
 	/*
-	 * void sha2_ce_transform(int blocks, u8 const *src, u32 *state,
-	 *			  u8 *head);
+	 * void sha2_ce_transform(struct sha256_state *sst, u8 const *src,
+				  int blocks);
 	 */
 ENTRY(sha2_ce_transform)
 	/* load state */
-	vld1.32		{dga-dgb}, [r2]
-
-	/* load partial input (if supplied) */
-	teq		r3, #0
-	beq		0f
-	vld1.32		{q0-q1}, [r3]!
-	vld1.32		{q2-q3}, [r3]
-	teq		r0, #0
-	b		1f
+	vld1.32		{dga-dgb}, [r0]
 
 	/* load input */
 0:	vld1.32		{q0-q1}, [r1]!
 	vld1.32		{q2-q3}, [r1]!
-	subs		r0, r0, #1
+	subs		r2, r2, #1
 
-1:
 #ifndef CONFIG_CPU_BIG_ENDIAN
 	vrev32.8	q0, q0
 	vrev32.8	q1, q1
···
 	bne		0b
 
 	/* store new state */
-	vst1.32		{dga-dgb}, [r2]
+	vst1.32		{dga-dgb}, [r0]
 	bx		lr
 ENDPROC(sha2_ce_transform)

arch/arm/crypto/sha2-ce-glue.c

···
 
 #include <crypto/internal/hash.h>
 #include <crypto/sha.h>
+#include <crypto/sha256_base.h>
 #include <linux/crypto.h>
 #include <linux/module.h>
 
···
 #include <asm/neon.h>
 #include <asm/unaligned.h>
 
+#include "sha256_glue.h"
+
 MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash using ARMv8 Crypto Extensions");
 MODULE_AUTHOR("Ard Biesheuvel <[e-mail]>");
 MODULE_LICENSE("GPL v2");
 
-asmlinkage void sha2_ce_transform(int blocks, u8 const *src, u32 *state,
-				  u8 *head);
+asmlinkage void sha2_ce_transform(struct sha256_state *sst, u8 const *src,
+				  int blocks);
 
-static int sha224_init(struct shash_desc *desc)
+static int sha2_ce_update(struct shash_desc *desc, const u8 *data,
+			  unsigned int len)
 {
 	struct sha256_state *sctx = shash_desc_ctx(desc);
 
-	*sctx = (struct sha256_state){
-		.state = {
-			SHA224_H0, SHA224_H1, SHA224_H2, SHA224_H3,
-			SHA224_H4, SHA224_H5, SHA224_H6, SHA224_H7,
-		}
-	};
+	if (!may_use_simd() ||
+	    (sctx->count % SHA256_BLOCK_SIZE) + len < SHA256_BLOCK_SIZE)
+		return crypto_sha256_arm_update(desc, data, len);
+
+	kernel_neon_begin();
+	sha256_base_do_update(desc, data, len,
+			      (sha256_block_fn *)sha2_ce_transform);
+	kernel_neon_end();
+
 	return 0;
 }
 
-static int sha256_init(struct shash_desc *desc)
+static int sha2_ce_finup(struct shash_desc *desc, const u8 *data,
+			 unsigned int len, u8 *out)
 {
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-
-	*sctx = (struct sha256_state){
-		.state = {
-			SHA256_H0, SHA256_H1, SHA256_H2, SHA256_H3,
-			SHA256_H4, SHA256_H5, SHA256_H6, SHA256_H7,
-		}
-	};
-	return 0;
-}
-
-static int sha2_update(struct shash_desc *desc, const u8 *data,
-		       unsigned int len)
-{
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-	unsigned int partial;
-
 	if (!may_use_simd())
-		return crypto_sha256_update(desc, data, len);
+		return crypto_sha256_arm_finup(desc, data, len, out);
 
-	partial = sctx->count % SHA256_BLOCK_SIZE;
-	sctx->count += len;
-
-	if ((partial + len) >= SHA256_BLOCK_SIZE) {
-		int blocks;
-
-		if (partial) {
-			int p = SHA256_BLOCK_SIZE - partial;
-
-			memcpy(sctx->buf + partial, data, p);
-			data += p;
-			len -= p;
-		}
-
-		blocks = len / SHA256_BLOCK_SIZE;
-		len %= SHA256_BLOCK_SIZE;
-
-		kernel_neon_begin();
-		sha2_ce_transform(blocks, data, sctx->state,
-				  partial ? sctx->buf : NULL);
-		kernel_neon_end();
-
-		data += blocks * SHA256_BLOCK_SIZE;
-		partial = 0;
-	}
+	kernel_neon_begin();
 	if (len)
-		memcpy(sctx->buf + partial, data, len);
-	return 0;
+		sha256_base_do_update(desc, data, len,
+				      (sha256_block_fn *)sha2_ce_transform);
+	sha256_base_do_finalize(desc, (sha256_block_fn *)sha2_ce_transform);
+	kernel_neon_end();
+
+	return sha256_base_finish(desc, out);
 }
 
-static void sha2_final(struct shash_desc *desc)
+static int sha2_ce_final(struct shash_desc *desc, u8 *out)
 {
-	static const u8 padding[SHA256_BLOCK_SIZE] = { 0x80, };
-
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-	__be64 bits = cpu_to_be64(sctx->count << 3);
-	u32 padlen = SHA256_BLOCK_SIZE
-		     - ((sctx->count + sizeof(bits)) % SHA256_BLOCK_SIZE);
-
-	sha2_update(desc, padding, padlen);
-	sha2_update(desc, (const u8 *)&bits, sizeof(bits));
-}
-
-static int sha224_final(struct shash_desc *desc, u8 *out)
-{
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-	__be32 *dst = (__be32 *)out;
-	int i;
-
-	sha2_final(desc);
-
-	for (i = 0; i < SHA224_DIGEST_SIZE / sizeof(__be32); i++)
-		put_unaligned_be32(sctx->state[i], dst++);
-
-	*sctx = (struct sha256_state){};
-	return 0;
-}
-
-static int sha256_final(struct shash_desc *desc, u8 *out)
-{
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-	__be32 *dst = (__be32 *)out;
-	int i;
-
-	sha2_final(desc);
-
-	for (i = 0; i < SHA256_DIGEST_SIZE / sizeof(__be32); i++)
-		put_unaligned_be32(sctx->state[i], dst++);
-
-	*sctx = (struct sha256_state){};
-	return 0;
-}
-
-static int sha2_export(struct shash_desc *desc, void *out)
-{
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-	struct sha256_state *dst = out;
-
-	*dst = *sctx;
-	return 0;
-}
-
-static int sha2_import(struct shash_desc *desc, const void *in)
-{
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-	struct sha256_state const *src = in;
-
-	*sctx = *src;
-	return 0;
+	return sha2_ce_finup(desc, NULL, 0, out);
 }
 
 static struct shash_alg algs[] = { {
-	.init			= sha224_init,
-	.update			= sha2_update,
-	.final			= sha224_final,
-	.export			= sha2_export,
-	.import			= sha2_import,
+	.init			= sha224_base_init,
+	.update			= sha2_ce_update,
+	.final			= sha2_ce_final,
+	.finup			= sha2_ce_finup,
 	.descsize		= sizeof(struct sha256_state),
 	.digestsize		= SHA224_DIGEST_SIZE,
-	.statesize		= sizeof(struct sha256_state),
 	.base			= {
 		.cra_name		= "sha224",
 		.cra_driver_name	= "sha224-ce",
···
 		.cra_module		= THIS_MODULE,
 	}
 }, {
-	.init			= sha256_init,
-	.update			= sha2_update,
-	.final			= sha256_final,
-	.export			= sha2_export,
-	.import			= sha2_import,
+	.init			= sha256_base_init,
+	.update			= sha2_ce_update,
+	.final			= sha2_ce_final,
+	.finup			= sha2_ce_finup,
 	.descsize		= sizeof(struct sha256_state),
 	.digestsize		= SHA256_DIGEST_SIZE,
-	.statesize		= sizeof(struct sha256_state),
 	.base			= {
 		.cra_name		= "sha256",
 		.cra_driver_name	= "sha256-ce",