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From:   Ard Biesheuvel <ard.biesheuvel@linaro.org>
To:     linux-crypto@vger.kernel.org
Cc:     linux-arm-kernel@lists.infradead.org,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        David Miller <davem@davemloft.net>,
        Greg KH <gregkh@linuxfoundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        "Jason A . Donenfeld" <Jason@zx2c4.com>,
        Samuel Neves <sneves@dei.uc.pt>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Eric Biggers <ebiggers@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Martin Willi <martin@strongswan.org>
Subject: [RFC PATCH 03/20] crypto: arm64/chacha - expose arm64 ChaCha routine as library function
Date:   Sun, 29 Sep 2019 19:38:33 +0200
Message-Id: <20190929173850.26055-4-ard.biesheuvel@linaro.org>
In-Reply-To: <20190929173850.26055-1-ard.biesheuvel@linaro.org>
References: <20190929173850.26055-1-ard.biesheuvel@linaro.org>
Sender: linux-crypto-owner@vger.kernel.org
Precedence: bulk

Expose the accelerated NEON ChaCha routine directly as a symbol
export so that users of the ChaCha library can use it directly.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 arch/arm64/crypto/Kconfig            |  1 +
 arch/arm64/crypto/chacha-neon-glue.c | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index 4922c4451e7c..09aa69ccc792 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -104,6 +104,7 @@ config CRYPTO_CHACHA20_NEON
 	depends on KERNEL_MODE_NEON
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_CHACHA20
+	select CRYPTO_ARCH_HAVE_LIB_CHACHA
 
 config CRYPTO_NHPOLY1305_NEON
 	tristate "NHPoly1305 hash function using NEON instructions (for Adiantum)"
diff --git a/arch/arm64/crypto/chacha-neon-glue.c b/arch/arm64/crypto/chacha-neon-glue.c
index d4cc61bfe79d..26c12b19a4ad 100644
--- a/arch/arm64/crypto/chacha-neon-glue.c
+++ b/arch/arm64/crypto/chacha-neon-glue.c
@@ -59,6 +59,18 @@ static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
 	}
 }
 
+void chacha_crypt(u32 *state, u8 *dst, const u8 *src, unsigned int bytes,
+		  int nrounds)
+{
+	if (bytes <= CHACHA_BLOCK_SIZE || !crypto_simd_usable())
+		return chacha_crypt_generic(state, dst, src, bytes, nrounds);
+
+	kernel_neon_begin();
+	chacha_doneon(state, dst, src, bytes, nrounds);
+	kernel_neon_end();
+}
+EXPORT_SYMBOL(chacha_crypt);
+
 static int chacha_neon_stream_xor(struct skcipher_request *req,
 				  const struct chacha_ctx *ctx, const u8 *iv)
 {
-- 
2.17.1