/* SPDX-License-Identifier: MIT
 *
 * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
 */

#include <zinc/chacha20.h>
#include <asm/hwcap.h>
#include <asm/neon.h>

asmlinkage void chacha20_arm(u8 *out, const u8 *in, const size_t len,
			     const u32 key[8], const u32 counter[4]);
#if IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&                                     \
	(defined(CONFIG_64BIT) || __LINUX_ARM_ARCH__ >= 7)
#define ARM_USE_NEON
asmlinkage void chacha20_neon(u8 *out, const u8 *in, const size_t len,
			      const u32 key[8], const u32 counter[4]);
#endif

static bool chacha20_use_neon __ro_after_init;

void __init chacha20_fpu_init(void)
{
#if defined(CONFIG_ARM64)
	chacha20_use_neon = elf_hwcap & HWCAP_ASIMD;
#elif defined(CONFIG_ARM)
	chacha20_use_neon = elf_hwcap & HWCAP_NEON;
#endif
}

static inline bool chacha20_arch(u8 *dst, const u8 *src, const size_t len,
				 const u32 key[8], const u32 counter[4],
				 simd_context_t simd_context)
{
#if defined(ARM_USE_NEON)
	if (simd_context == HAVE_FULL_SIMD && chacha20_use_neon) {
		chacha20_neon(dst, src, len, key, counter);
		return true;
	}
#endif
	chacha20_arm(dst, src, len, key, counter);
	return true;
}

static inline bool hchacha20_arch(u8 *derived_key, const u8 *nonce,
				  const u8 *key, simd_context_t simd_context)
{
	return false;
}

#define HAVE_CHACHA20_ARCH_IMPLEMENTATION