crypto: arm64/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 <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/arm64/crypto/sha2-ce-core.S

@@ -73,8 +73,8 @@
 	.word		0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 
 	/*
-	 * void sha2_ce_transform(int blocks, u8 const *src, u32 *state,
-	 *                        u8 *head, long bytes)
+	 * void sha2_ce_transform(struct sha256_ce_state *sst, u8 const *src,
+	 *			  int blocks)
 	 */
 ENTRY(sha2_ce_transform)
 	/* load round constants */
@@ -85,24 +85,21 @@ ENTRY(sha2_ce_transform)
 	ld1		{v12.4s-v15.4s}, [x8]
 
 	/* load state */
-	ldp		dga, dgb, [x2]
+	ldp		dga, dgb, [x0]
 
-	/* load partial input (if supplied) */
-	cbz		x3, 0f
-	ld1		{v16.4s-v19.4s}, [x3]
-	b		1f
+	/* load sha256_ce_state::finalize */
+	ldr		w4, [x0, #:lo12:sha256_ce_offsetof_finalize]
 
 	/* load input */
 0:	ld1		{v16.4s-v19.4s}, [x1], #64
-	sub		w0, w0, #1
+	sub		w2, w2, #1
 
-1:
 CPU_LE(	rev32		v16.16b, v16.16b	)
 CPU_LE(	rev32		v17.16b, v17.16b	)
 CPU_LE(	rev32		v18.16b, v18.16b	)
 CPU_LE(	rev32		v19.16b, v19.16b	)
 
-2:	add		t0.4s, v16.4s, v0.4s
+1:	add		t0.4s, v16.4s, v0.4s
 	mov		dg0v.16b, dgav.16b
 	mov		dg1v.16b, dgbv.16b
 
@@ -131,15 +128,15 @@ CPU_LE(	rev32		v19.16b, v19.16b	)
 	add		dgbv.4s, dgbv.4s, dg1v.4s
 
 	/* handled all input blocks? */
-	cbnz		w0, 0b
+	cbnz		w2, 0b
 
 	/*
 	 * Final block: add padding and total bit count.
-	 * Skip if we have no total byte count in x4. In that case, the input
-	 * size was not a round multiple of the block size, and the padding is
-	 * handled by the C code.
+	 * Skip if the input size was not a round multiple of the block size,
+	 * the padding is handled by the C code in that case.
 	 */
 	cbz		x4, 3f
+	ldr		x4, [x0, #:lo12:sha256_ce_offsetof_count]
 	movi		v17.2d, #0
 	mov		x8, #0x80000000
 	movi		v18.2d, #0
@@ -148,9 +145,9 @@ CPU_LE(	rev32		v19.16b, v19.16b	)
 	mov		x4, #0
 	mov		v19.d[0], xzr
 	mov		v19.d[1], x7
-	b		2b
+	b		1b
 
 	/* store new state */
-3:	stp		dga, dgb, [x2]
+3:	stp		dga, dgb, [x0]
 	ret
 ENDPROC(sha2_ce_transform)

arch/arm64/crypto/sha2-ce-glue.c

@@ -12,206 +12,82 @@
 #include <asm/unaligned.h>
 #include <crypto/internal/hash.h>
 #include <crypto/sha.h>
+#include <crypto/sha256_base.h>
 #include <linux/cpufeature.h>
 #include <linux/crypto.h>
 #include <linux/module.h>
 
+#define ASM_EXPORT(sym, val) \
+	asm(".globl " #sym "; .set " #sym ", %0" :: "I"(val));
+
 MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash using ARMv8 Crypto Extensions");
 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 MODULE_LICENSE("GPL v2");
 
-asmlinkage int sha2_ce_transform(int blocks, u8 const *src, u32 *state,
-				 u8 *head, long bytes);
-
-static int sha224_init(struct shash_desc *desc)
-{
-	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,
-		}
-	};
-	return 0;
-}
-
-static int sha256_init(struct shash_desc *desc)
-{
-	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 = 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;
-		}
+struct sha256_ce_state {
+	struct sha256_state	sst;
+	u32			finalize;
+};
 
-		blocks = len / SHA256_BLOCK_SIZE;
-		len %= SHA256_BLOCK_SIZE;
+asmlinkage void sha2_ce_transform(struct sha256_ce_state *sst, u8 const *src,
+				  int blocks);
 
-		kernel_neon_begin_partial(28);
-		sha2_ce_transform(blocks, data, sctx->state,
-				  partial ? sctx->buf : NULL, 0);
-		kernel_neon_end();
-
-		data += blocks * SHA256_BLOCK_SIZE;
-		partial = 0;
-	}
-	if (len)
-		memcpy(sctx->buf + partial, data, len);
-	return 0;
-}
-
-static void sha2_final(struct shash_desc *desc)
+static int sha256_ce_update(struct shash_desc *desc, const u8 *data,
+			    unsigned int len)
 {
-	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;
-}
+	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
 
-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->finalize = 0;
+	kernel_neon_begin_partial(28);
+	sha256_base_do_update(desc, data, len,
+			      (sha256_block_fn *)sha2_ce_transform);
+	kernel_neon_end();
 
-	*sctx = (struct sha256_state){};
 	return 0;
 }
 
-static void sha2_finup(struct shash_desc *desc, const u8 *data,
-		       unsigned int len)
+static int sha256_ce_finup(struct shash_desc *desc, const u8 *data,
+			   unsigned int len, u8 *out)
 {
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-	int blocks;
+	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
+	bool finalize = !sctx->sst.count && !(len % SHA256_BLOCK_SIZE);
 
-	if (sctx->count || !len || (len % SHA256_BLOCK_SIZE)) {
-		sha2_update(desc, data, len);
-		sha2_final(desc);
-		return;
-	}
+	ASM_EXPORT(sha256_ce_offsetof_count,
+		   offsetof(struct sha256_ce_state, sst.count));
+	ASM_EXPORT(sha256_ce_offsetof_finalize,
+		   offsetof(struct sha256_ce_state, finalize));
 
 	/*
-	 * Use a fast path if the input is a multiple of 64 bytes. In
-	 * this case, there is no need to copy data around, and we can
-	 * perform the entire digest calculation in a single invocation
-	 * of sha2_ce_transform()
+	 * Allow the asm code to perform the finalization if there is no
+	 * partial data and the input is a round multiple of the block size.
 	 */
-	blocks = len / SHA256_BLOCK_SIZE;
+	sctx->finalize = finalize;
 
 	kernel_neon_begin_partial(28);
-	sha2_ce_transform(blocks, data, sctx->state, NULL, len);
+	sha256_base_do_update(desc, data, len,
+			      (sha256_block_fn *)sha2_ce_transform);
+	if (!finalize)
+		sha256_base_do_finalize(desc,
+					(sha256_block_fn *)sha2_ce_transform);
 	kernel_neon_end();
+	return sha256_base_finish(desc, out);
 }
 
-static int sha224_finup(struct shash_desc *desc, const u8 *data,
-			unsigned int len, u8 *out)
+static int sha256_ce_final(struct shash_desc *desc, u8 *out)
 {
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-	__be32 *dst = (__be32 *)out;
-	int i;
-
-	sha2_finup(desc, data, len);
-
-	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_finup(struct shash_desc *desc, const u8 *data,
-			unsigned int len, u8 *out)
-{
-	struct sha256_state *sctx = shash_desc_ctx(desc);
-	__be32 *dst = (__be32 *)out;
-	int i;
-
-	sha2_finup(desc, data, len);
-
-	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;
+	kernel_neon_begin_partial(28);
+	sha256_base_do_finalize(desc, (sha256_block_fn *)sha2_ce_transform);
+	kernel_neon_end();
+	return sha256_base_finish(desc, out);
 }
 
 static struct shash_alg algs[] = { {
-	.init			= sha224_init,
-	.update			= sha2_update,
-	.final			= sha224_final,
-	.finup			= sha224_finup,
-	.export			= sha2_export,
-	.import			= sha2_import,
-	.descsize		= sizeof(struct sha256_state),
+	.init			= sha224_base_init,
+	.update			= sha256_ce_update,
+	.final			= sha256_ce_final,
+	.finup			= sha256_ce_finup,
+	.descsize		= sizeof(struct sha256_ce_state),
 	.digestsize		= SHA224_DIGEST_SIZE,
-	.statesize		= sizeof(struct sha256_state),
 	.base			= {
 		.cra_name		= "sha224",
 		.cra_driver_name	= "sha224-ce",
@@ -221,15 +97,12 @@ static struct shash_alg algs[] = { {
 		.cra_module		= THIS_MODULE,
 	}
 }, {
-	.init			= sha256_init,
-	.update			= sha2_update,
-	.final			= sha256_final,
-	.finup			= sha256_finup,
-	.export			= sha2_export,
-	.import			= sha2_import,
-	.descsize		= sizeof(struct sha256_state),
+	.init			= sha256_base_init,
+	.update			= sha256_ce_update,
+	.final			= sha256_ce_final,
+	.finup			= sha256_ce_finup,
+	.descsize		= sizeof(struct sha256_ce_state),
 	.digestsize		= SHA256_DIGEST_SIZE,
-	.statesize		= sizeof(struct sha256_state),
 	.base			= {
 		.cra_name		= "sha256",
 		.cra_driver_name	= "sha256-ce",