[PATCH 5/17] zinc: Add x86 accelerated ChaCha20

Herbert Xu
2019-03-22T06:31:47Z

This patch exposes the crypto API x86 chacha20 implementation through
zinc.

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

lib/zinc/Kconfig | 1
lib/zinc/chacha20/chacha20-x86_64-glue.c | 55 +++++++++++++++++++++++++++++++
lib/zinc/chacha20/chacha20.c | 4 ++
3 files changed, 60 insertions(+)

diff --git a/lib/zinc/Kconfig b/lib/zinc/Kconfig
index 1fffd0a1a74c..010547fa6c9d 100644
--- a/lib/zinc/Kconfig
+++ b/lib/zinc/Kconfig
@@ -1,6 +1,7 @@
config ZINC_CHACHA20
tristate
select CRYPTO_CHACHA20
+ select CRYPTO_CHACHA20_X86_64 if ZINC_ARCH_X86_64

config ZINC_SELFTEST
bool "Zinc cryptography library self-tests"
diff --git a/lib/zinc/chacha20/chacha20-x86_64-glue.c b/lib/zinc/chacha20/chacha20-x86_64-glue.c
new file mode 100644
index 000000000000..e0b387b09c04
--- /dev/null
+++ b/lib/zinc/chacha20/chacha20-x86_64-glue.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#include <asm/fpu/api.h>
+#include <asm/cpufeature.h>
+#include <asm/processor.h>
+#include <asm/intel-family.h>
+#include <crypto/chacha.h>
+
+static bool chacha20_use_ssse3 __ro_after_init;
+static bool *const chacha20_nobs[] __initconst = {
+ &chacha20_use_ssse3 };
+
+static void __init chacha20_fpu_init(void)
+{
+ chacha20_use_ssse3 = boot_cpu_has(X86_FEATURE_SSSE3);
+}
+
+static inline bool chacha20_arch(struct chacha20_ctx *ctx, u8 *dst,
+ const u8 *src, size_t len,
+ simd_context_t *simd_context)
+{
+ /* SIMD disables preemption, so relax after processing each page. */
+ BUILD_BUG_ON(PAGE_SIZE < CHACHA20_BLOCK_SIZE ||
+ PAGE_SIZE % CHACHA20_BLOCK_SIZE);
+
+ if (!IS_ENABLED(CONFIG_AS_SSSE3) || !chacha20_use_ssse3 ||
+ len <= CHACHA20_BLOCK_SIZE || !simd_use(simd_context))
+ return false;
+
+ for (;;) {
+ const size_t bytes = min_t(size_t, len, PAGE_SIZE);
+
+ crypto_chacha_dosimd(ctx->state, dst, src, bytes, 20);
+
+ len -= bytes;
+ if (!len)
+ break;
+ dst += bytes;
+ src += bytes;
+ simd_relax(simd_context);
+ }
+
+ return true;
+}
+
+static inline bool hchacha20_arch(u32 derived_key[CHACHA20_KEY_WORDS],
+ const u8 nonce[HCHACHA20_NONCE_SIZE],
+ const u8 key[HCHACHA20_KEY_SIZE],
+ simd_context_t *simd_context)
+{
+ return false;
+}
diff --git a/lib/zinc/chacha20/chacha20.c b/lib/zinc/chacha20/chacha20.c
index cfbdaf4384dc..c84fe504623f 100644
--- a/lib/zinc/chacha20/chacha20.c
+++ b/lib/zinc/chacha20/chacha20.c
@@ -17,6 +17,9 @@
#include <crypto/algapi.h> // For crypto_xor_cpy.
#include <crypto/chacha.h>

+#if defined(CONFIG_ZINC_ARCH_X86_64)
+#include "chacha20-x86_64-glue.c"
+#else
static bool *const chacha20_nobs[] __initconst = { };
static void __init chacha20_fpu_init(void)
{
@@ -34,6 +37,7 @@ static inline bool hchacha20_arch(u32 derived_key[CHACHA20_KEY_WORDS],
{
return false;
}
+#endif

void chacha20(struct chacha20_ctx *ctx, u8 *dst, const u8 *src, u32 len,
simd_context_t *simd_context)