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f53d18a4e6
Before modifying the prototypes of kernel_neon_begin() and kernel_neon_end() to accommodate kernel mode FP/SIMD state buffers allocated on the stack, move arm64 to the new 'ksimd' scoped guard API, which encapsulates the calls to those functions. For symmetry, do the same for 32-bit ARM too. Reviewed-by: Eric Biggers <ebiggers@kernel.org> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
115 lines
3.1 KiB
C
115 lines
3.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* ChaCha and HChaCha functions (ARM optimized)
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*
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* Copyright (C) 2016-2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
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* Copyright (C) 2015 Martin Willi
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*/
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#include <crypto/internal/simd.h>
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#include <linux/jump_label.h>
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#include <linux/kernel.h>
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#include <asm/cputype.h>
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#include <asm/hwcap.h>
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#include <asm/simd.h>
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asmlinkage void chacha_block_xor_neon(const struct chacha_state *state,
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u8 *dst, const u8 *src, int nrounds);
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asmlinkage void chacha_4block_xor_neon(const struct chacha_state *state,
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u8 *dst, const u8 *src,
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int nrounds, unsigned int nbytes);
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asmlinkage void hchacha_block_arm(const struct chacha_state *state,
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u32 out[HCHACHA_OUT_WORDS], int nrounds);
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asmlinkage void hchacha_block_neon(const struct chacha_state *state,
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u32 out[HCHACHA_OUT_WORDS], int nrounds);
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asmlinkage void chacha_doarm(u8 *dst, const u8 *src, unsigned int bytes,
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const struct chacha_state *state, int nrounds);
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static __ro_after_init DEFINE_STATIC_KEY_FALSE(use_neon);
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static inline bool neon_usable(void)
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{
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return static_branch_likely(&use_neon) && crypto_simd_usable();
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}
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static void chacha_doneon(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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u8 buf[CHACHA_BLOCK_SIZE];
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while (bytes > CHACHA_BLOCK_SIZE) {
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unsigned int l = min(bytes, CHACHA_BLOCK_SIZE * 4U);
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chacha_4block_xor_neon(state, dst, src, nrounds, l);
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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] += DIV_ROUND_UP(l, CHACHA_BLOCK_SIZE);
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}
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if (bytes) {
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const u8 *s = src;
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u8 *d = dst;
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if (bytes != CHACHA_BLOCK_SIZE)
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s = d = memcpy(buf, src, bytes);
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chacha_block_xor_neon(state, d, s, nrounds);
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if (d != dst)
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memcpy(dst, buf, bytes);
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state->x[12]++;
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}
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}
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static void hchacha_block_arch(const struct chacha_state *state,
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u32 out[HCHACHA_OUT_WORDS], int nrounds)
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{
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if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon_usable()) {
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hchacha_block_arm(state, out, nrounds);
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} else {
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scoped_ksimd()
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hchacha_block_neon(state, out, nrounds);
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}
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}
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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 (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon_usable() ||
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bytes <= CHACHA_BLOCK_SIZE) {
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chacha_doarm(dst, src, bytes, state, nrounds);
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state->x[12] += DIV_ROUND_UP(bytes, CHACHA_BLOCK_SIZE);
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return;
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}
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do {
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unsigned int todo = min_t(unsigned int, bytes, SZ_4K);
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scoped_ksimd()
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chacha_doneon(state, dst, src, todo, nrounds);
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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 (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) {
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switch (read_cpuid_part()) {
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case ARM_CPU_PART_CORTEX_A7:
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case ARM_CPU_PART_CORTEX_A5:
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/*
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* The Cortex-A7 and Cortex-A5 do not perform well with
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* the NEON implementation but do incredibly with the
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* scalar one and use less power.
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*/
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break;
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default:
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static_branch_enable(&use_neon);
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}
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}
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}
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