crypto: lib/sha256 - Add helpers for block-based shash

Add an internal sha256_finup helper and move the finalisation code
from __sha256_final into it.

Also add sha256_choose_blocks and CRYPTO_ARCH_HAVE_LIB_SHA256_SIMD
so that the Crypto API can use the SIMD block function unconditionally.
The Crypto API must not be used in hard IRQs and there is no reason
to have a fallback path for hardirqs.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 45 insertions, 0 deletions

diff --git a/include/crypto/internal/sha2.h b/include/crypto/internal/sha2.h
index d641c67abcbc..fff156f66edc 100644
--- a/include/crypto/internal/sha2.h
+++ b/include/crypto/internal/sha2.h
@@ -3,7 +3,12 @@
 #ifndef _CRYPTO_INTERNAL_SHA2_H
 #define _CRYPTO_INTERNAL_SHA2_H
 
+#include <crypto/internal/simd.h>
 #include <crypto/sha2.h>
+#include <linux/compiler_attributes.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
 
 void sha256_update_generic(struct sha256_state *sctx,
 			   const u8 *data, size_t len);
@@ -24,5 +29,45 @@ void sha256_blocks_generic(u32 state[SHA256_STATE_WORDS],
 			   const u8 *data, size_t nblocks);
 void sha256_blocks_arch(u32 state[SHA256_STATE_WORDS],
 			const u8 *data, size_t nblocks);
+void sha256_blocks_simd(u32 state[SHA256_STATE_WORDS],
+			const u8 *data, size_t nblocks);
+
+static inline void sha256_choose_blocks(
+	u32 state[SHA256_STATE_WORDS], const u8 *data, size_t nblocks,
+	bool force_generic, bool force_simd)
+{
+	if (!IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_SHA256) || force_generic)
+		sha256_blocks_generic(state, data, nblocks);
+	else if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_SHA256_SIMD) &&
+		 (force_simd || crypto_simd_usable()))
+		sha256_blocks_simd(state, data, nblocks);
+	else
+		sha256_blocks_arch(state, data, nblocks);
+}
+
+static __always_inline void sha256_finup(
+	struct crypto_sha256_state *sctx, u8 buf[SHA256_BLOCK_SIZE],
+	size_t len, u8 out[SHA256_DIGEST_SIZE], size_t digest_size,
+	bool force_generic, bool force_simd)
+{
+	const size_t bit_offset = SHA256_BLOCK_SIZE - 8;
+	__be64 *bits = (__be64 *)&buf[bit_offset];
+	int i;
+
+	buf[len++] = 0x80;
+	if (len > bit_offset) {
+		memset(&buf[len], 0, SHA256_BLOCK_SIZE - len);
+		sha256_choose_blocks(sctx->state, buf, 1, force_generic,
+				     force_simd);
+		len = 0;
+	}
+
+	memset(&buf[len], 0, bit_offset - len);
+	*bits = cpu_to_be64(sctx->count << 3);
+	sha256_choose_blocks(sctx->state, buf, 1, force_generic, force_simd);
+
+	for (i = 0; i < digest_size; i += 4)
+		put_unaligned_be32(sctx->state[i / 4], out + i);
+}
 
 #endif /* _CRYPTO_INTERNAL_SHA2_H */