diff options
Diffstat (limited to 'arch/arm64/lib/crypto/chacha-neon-glue.c')
| -rw-r--r-- | arch/arm64/lib/crypto/chacha-neon-glue.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/arch/arm64/lib/crypto/chacha-neon-glue.c b/arch/arm64/lib/crypto/chacha-neon-glue.c new file mode 100644 index 000000000000..d0188f974ca5 --- /dev/null +++ b/arch/arm64/lib/crypto/chacha-neon-glue.c @@ -0,0 +1,119 @@ +/* + * ChaCha and HChaCha functions (ARM64 optimized) + * + * Copyright (C) 2016 - 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Based on: + * ChaCha20 256-bit cipher algorithm, RFC7539, SIMD glue code + * + * Copyright (C) 2015 Martin Willi + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <crypto/chacha.h> +#include <crypto/internal/simd.h> +#include <linux/jump_label.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include <asm/hwcap.h> +#include <asm/neon.h> +#include <asm/simd.h> + +asmlinkage void chacha_block_xor_neon(const struct chacha_state *state, + u8 *dst, const u8 *src, int nrounds); +asmlinkage void chacha_4block_xor_neon(const struct chacha_state *state, + u8 *dst, const u8 *src, + int nrounds, int bytes); +asmlinkage void hchacha_block_neon(const struct chacha_state *state, + u32 out[HCHACHA_OUT_WORDS], int nrounds); + +static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon); + +static void chacha_doneon(struct chacha_state *state, u8 *dst, const u8 *src, + int bytes, int nrounds) +{ + while (bytes > 0) { + int l = min(bytes, CHACHA_BLOCK_SIZE * 5); + + if (l <= CHACHA_BLOCK_SIZE) { + u8 buf[CHACHA_BLOCK_SIZE]; + + memcpy(buf, src, l); + chacha_block_xor_neon(state, buf, buf, nrounds); + memcpy(dst, buf, l); + state->x[12] += 1; + break; + } + chacha_4block_xor_neon(state, dst, src, nrounds, l); + bytes -= l; + src += l; + dst += l; + state->x[12] += DIV_ROUND_UP(l, CHACHA_BLOCK_SIZE); + } +} + +void hchacha_block_arch(const struct chacha_state *state, + u32 out[HCHACHA_OUT_WORDS], int nrounds) +{ + if (!static_branch_likely(&have_neon) || !crypto_simd_usable()) { + hchacha_block_generic(state, out, nrounds); + } else { + kernel_neon_begin(); + hchacha_block_neon(state, out, nrounds); + kernel_neon_end(); + } +} +EXPORT_SYMBOL(hchacha_block_arch); + +void chacha_crypt_arch(struct chacha_state *state, u8 *dst, const u8 *src, + unsigned int bytes, int nrounds) +{ + if (!static_branch_likely(&have_neon) || bytes <= CHACHA_BLOCK_SIZE || + !crypto_simd_usable()) + return chacha_crypt_generic(state, dst, src, bytes, nrounds); + + do { + unsigned int todo = min_t(unsigned int, bytes, SZ_4K); + + kernel_neon_begin(); + chacha_doneon(state, dst, src, todo, nrounds); + kernel_neon_end(); + + bytes -= todo; + src += todo; + dst += todo; + } while (bytes); +} +EXPORT_SYMBOL(chacha_crypt_arch); + +bool chacha_is_arch_optimized(void) +{ + return static_key_enabled(&have_neon); +} +EXPORT_SYMBOL(chacha_is_arch_optimized); + +static int __init chacha_simd_mod_init(void) +{ + if (cpu_have_named_feature(ASIMD)) + static_branch_enable(&have_neon); + return 0; +} +subsys_initcall(chacha_simd_mod_init); + +static void __exit chacha_simd_mod_exit(void) +{ +} +module_exit(chacha_simd_mod_exit); + +MODULE_DESCRIPTION("ChaCha and HChaCha functions (ARM64 optimized)"); +MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); +MODULE_LICENSE("GPL v2"); |