77 lines
1.7 KiB
C
77 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* ChaCha stream cipher (P10 accelerated)
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*
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* Copyright 2023- IBM Corp. All rights reserved.
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*/
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#include <crypto/internal/simd.h>
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#include <linux/kernel.h>
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#include <linux/cpufeature.h>
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#include <linux/sizes.h>
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#include <asm/simd.h>
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#include <asm/switch_to.h>
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asmlinkage void chacha_p10le_8x(const struct chacha_state *state, u8 *dst,
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const u8 *src, unsigned int len, int nrounds);
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static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_p10);
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static void vsx_begin(void)
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{
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preempt_disable();
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enable_kernel_vsx();
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}
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static void vsx_end(void)
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{
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disable_kernel_vsx();
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preempt_enable();
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}
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static void chacha_p10_do_8x(struct chacha_state *state, u8 *dst, const u8 *src,
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unsigned int bytes, int nrounds)
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{
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unsigned int l = bytes & ~0x0FF;
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if (l > 0) {
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chacha_p10le_8x(state, dst, src, l, nrounds);
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bytes -= l;
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src += l;
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dst += l;
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state->x[12] += l / CHACHA_BLOCK_SIZE;
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}
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if (bytes > 0)
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chacha_crypt_generic(state, dst, src, bytes, nrounds);
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}
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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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if (!static_branch_likely(&have_p10) || bytes <= CHACHA_BLOCK_SIZE ||
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!crypto_simd_usable())
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return chacha_crypt_generic(state, dst, src, bytes, nrounds);
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do {
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unsigned int todo = min_t(unsigned int, bytes, SZ_4K);
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vsx_begin();
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chacha_p10_do_8x(state, dst, src, todo, nrounds);
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vsx_end();
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bytes -= todo;
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src += todo;
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dst += todo;
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} while (bytes);
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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 (cpu_has_feature(CPU_FTR_ARCH_31))
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static_branch_enable(&have_p10);
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}
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