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98066f2f89
The ChaCha state matrix is 16 32-bit words. Currently it is represented
in the code as a raw u32 array, or even just a pointer to u32. This
weak typing is error-prone. Instead, introduce struct chacha_state:
struct chacha_state {
u32 x[16];
};
Convert all ChaCha and HChaCha functions to use struct chacha_state.
No functional changes.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
57 lines
1.5 KiB
C
57 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ChaCha stream cipher (s390 optimized)
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*
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* Copyright IBM Corp. 2021
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*/
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#define KMSG_COMPONENT "chacha_s390"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <crypto/chacha.h>
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#include <linux/cpufeature.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sizes.h>
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#include <asm/fpu.h>
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#include "chacha-s390.h"
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void hchacha_block_arch(const struct chacha_state *state,
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u32 *stream, int nrounds)
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{
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/* TODO: implement hchacha_block_arch() in assembly */
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hchacha_block_generic(state, stream, nrounds);
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}
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EXPORT_SYMBOL(hchacha_block_arch);
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void chacha_crypt_arch(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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/* s390 chacha20 implementation has 20 rounds hard-coded,
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* it cannot handle a block of data or less, but otherwise
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* it can handle data of arbitrary size
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*/
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if (bytes <= CHACHA_BLOCK_SIZE || nrounds != 20 || !cpu_has_vx()) {
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chacha_crypt_generic(state, dst, src, bytes, nrounds);
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} else {
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DECLARE_KERNEL_FPU_ONSTACK32(vxstate);
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kernel_fpu_begin(&vxstate, KERNEL_VXR);
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chacha20_vx(dst, src, bytes, &state->x[4], &state->x[12]);
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kernel_fpu_end(&vxstate, KERNEL_VXR);
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state->x[12] += round_up(bytes, CHACHA_BLOCK_SIZE) /
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CHACHA_BLOCK_SIZE;
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}
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}
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EXPORT_SYMBOL(chacha_crypt_arch);
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bool chacha_is_arch_optimized(void)
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{
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return cpu_has_vx();
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}
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EXPORT_SYMBOL(chacha_is_arch_optimized);
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MODULE_DESCRIPTION("ChaCha stream cipher (s390 optimized)");
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MODULE_LICENSE("GPL v2");
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