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@xxxxxxxxxx>
---
arch/arm/crypto/Kconfig | 1 +
arch/arm/crypto/chacha-neon-glue.c | 40 ++++++++++++++++++--
2 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
index b24df84a1d7a..70e4d5fe5bdb 100644
--- a/arch/arm/crypto/Kconfig
+++ b/arch/arm/crypto/Kconfig
@@ -130,6 +130,7 @@ 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 "NEON accelerated NHPoly1305 hash function (for Adiantum)"
diff --git a/arch/arm/crypto/chacha-neon-glue.c b/arch/arm/crypto/chacha-neon-glue.c
index 26576772f18b..eee0f6e4f5d2 100644
--- a/arch/arm/crypto/chacha-neon-glue.c
+++ b/arch/arm/crypto/chacha-neon-glue.c
@@ -36,6 +36,8 @@ asmlinkage void chacha_4block_xor_neon(const u32 *state, u8 *dst, const u8 *src,
int nrounds);
asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds);
+static bool have_neon __ro_after_init;
+
static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes, int nrounds)
{
@@ -62,6 +64,36 @@ static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
}
}
+void hchacha_block(const u32 *state, u32 *stream, int nrounds)
+{
+ if (!crypto_simd_usable()) {
+ hchacha_block_generic(state, stream, nrounds);
+ } else {
+ kernel_neon_begin();
+ hchacha_block_neon(state, stream, nrounds);
+ kernel_neon_end();
+ }
+}
+EXPORT_SYMBOL(hchacha_block);
+
+void chacha_init(u32 *state, const u32 *key, const u8 *iv)
+{
+ chacha_init_generic(state, key, iv);
+}
+EXPORT_SYMBOL(chacha_init);
+
+void chacha_crypt(u32 *state, u8 *dst, const u8 *src, unsigned int bytes,
+ int nrounds)
+{
+ if (!have_neon || 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)
{
@@ -177,15 +209,17 @@ static struct skcipher_alg algs[] = {
static int __init chacha_simd_mod_init(void)
{
- if (!(elf_hwcap & HWCAP_NEON))
- return -ENODEV;
+ have_neon = (elf_hwcap & HWCAP_NEON);
+ if (!have_neon)
+ return 0;
return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
}
static void __exit chacha_simd_mod_fini(void)
{
- crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
+ if (have_neon)
+ crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
}
module_init(chacha_simd_mod_init);
--
2.20.1
