mirror of https://github.com/torvalds/linux.git
52 lines
1.5 KiB
C
52 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* ChaCha stream cipher (RISC-V optimized)
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*
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* Copyright (C) 2023 SiFive, Inc.
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* Author: Jerry Shih <jerry.shih@sifive.com>
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*/
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#include <asm/simd.h>
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#include <asm/vector.h>
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#include <crypto/internal/simd.h>
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#include <linux/linkage.h>
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static __ro_after_init DEFINE_STATIC_KEY_FALSE(use_zvkb);
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asmlinkage void chacha_zvkb(struct chacha_state *state, const u8 *in, u8 *out,
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size_t nblocks, int nrounds);
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#define hchacha_block_arch hchacha_block_generic /* not implemented yet */
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static void chacha_crypt_arch(struct chacha_state *state, u8 *dst,
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const u8 *src, unsigned int bytes, int nrounds)
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{
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u8 block_buffer[CHACHA_BLOCK_SIZE];
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unsigned int full_blocks = bytes / CHACHA_BLOCK_SIZE;
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unsigned int tail_bytes = bytes % CHACHA_BLOCK_SIZE;
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if (!static_branch_likely(&use_zvkb) || !crypto_simd_usable())
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return chacha_crypt_generic(state, dst, src, bytes, nrounds);
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kernel_vector_begin();
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if (full_blocks) {
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chacha_zvkb(state, src, dst, full_blocks, nrounds);
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src += full_blocks * CHACHA_BLOCK_SIZE;
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dst += full_blocks * CHACHA_BLOCK_SIZE;
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}
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if (tail_bytes) {
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memcpy(block_buffer, src, tail_bytes);
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chacha_zvkb(state, block_buffer, block_buffer, 1, nrounds);
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memcpy(dst, block_buffer, tail_bytes);
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}
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kernel_vector_end();
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}
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#define chacha_mod_init_arch chacha_mod_init_arch
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static void chacha_mod_init_arch(void)
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{
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if (riscv_isa_extension_available(NULL, ZVKB) &&
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riscv_vector_vlen() >= 128)
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static_branch_enable(&use_zvkb);
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}
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