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1e1b6dbc3d
Move the arm CRC32 assembly code into the lib directory and wire it up to the library interface. This allows it to be used without going through the crypto API. It remains usable via the crypto API too via the shash algorithms that use the library interface. Thus all the arch-specific "shash" code becomes unnecessary and is removed. Note: to see the diff from arch/arm/crypto/crc32-ce-glue.c to arch/arm/lib/crc32-glue.c, view this commit with 'git show -M10'. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20241202010844.144356-6-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
123 lines
3 KiB
C
123 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions instructions
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*
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* Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
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*/
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#include <linux/cpufeature.h>
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#include <linux/crc32.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <crypto/internal/simd.h>
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#include <asm/hwcap.h>
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#include <asm/neon.h>
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#include <asm/simd.h>
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static DEFINE_STATIC_KEY_FALSE(have_crc32);
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static DEFINE_STATIC_KEY_FALSE(have_pmull);
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#define PMULL_MIN_LEN 64 /* min size of buffer for pmull functions */
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asmlinkage u32 crc32_pmull_le(const u8 buf[], u32 len, u32 init_crc);
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asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], u32 len);
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asmlinkage u32 crc32c_pmull_le(const u8 buf[], u32 len, u32 init_crc);
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asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], u32 len);
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static u32 crc32_le_scalar(u32 crc, const u8 *p, size_t len)
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{
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if (static_branch_likely(&have_crc32))
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return crc32_armv8_le(crc, p, len);
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return crc32_le_base(crc, p, len);
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}
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u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
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{
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if (len >= PMULL_MIN_LEN + 15 &&
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static_branch_likely(&have_pmull) && crypto_simd_usable()) {
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size_t n = -(uintptr_t)p & 15;
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/* align p to 16-byte boundary */
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if (n) {
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crc = crc32_le_scalar(crc, p, n);
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p += n;
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len -= n;
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}
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n = round_down(len, 16);
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kernel_neon_begin();
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crc = crc32_pmull_le(p, n, crc);
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kernel_neon_end();
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p += n;
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len -= n;
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}
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return crc32_le_scalar(crc, p, len);
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}
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EXPORT_SYMBOL(crc32_le_arch);
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static u32 crc32c_le_scalar(u32 crc, const u8 *p, size_t len)
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{
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if (static_branch_likely(&have_crc32))
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return crc32c_armv8_le(crc, p, len);
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return crc32c_le_base(crc, p, len);
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}
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u32 crc32c_le_arch(u32 crc, const u8 *p, size_t len)
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{
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if (len >= PMULL_MIN_LEN + 15 &&
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static_branch_likely(&have_pmull) && crypto_simd_usable()) {
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size_t n = -(uintptr_t)p & 15;
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/* align p to 16-byte boundary */
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if (n) {
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crc = crc32c_le_scalar(crc, p, n);
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p += n;
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len -= n;
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}
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n = round_down(len, 16);
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kernel_neon_begin();
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crc = crc32c_pmull_le(p, n, crc);
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kernel_neon_end();
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p += n;
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len -= n;
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}
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return crc32c_le_scalar(crc, p, len);
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}
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EXPORT_SYMBOL(crc32c_le_arch);
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u32 crc32_be_arch(u32 crc, const u8 *p, size_t len)
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{
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return crc32_be_base(crc, p, len);
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}
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EXPORT_SYMBOL(crc32_be_arch);
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static int __init crc32_arm_init(void)
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{
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if (elf_hwcap2 & HWCAP2_CRC32)
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static_branch_enable(&have_crc32);
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if (elf_hwcap2 & HWCAP2_PMULL)
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static_branch_enable(&have_pmull);
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return 0;
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}
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arch_initcall(crc32_arm_init);
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static void __exit crc32_arm_exit(void)
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{
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}
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module_exit(crc32_arm_exit);
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u32 crc32_optimizations(void)
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{
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if (elf_hwcap2 & (HWCAP2_CRC32 | HWCAP2_PMULL))
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return CRC32_LE_OPTIMIZATION | CRC32C_OPTIMIZATION;
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return 0;
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}
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EXPORT_SYMBOL(crc32_optimizations);
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MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
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MODULE_DESCRIPTION("Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions");
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MODULE_LICENSE("GPL v2");
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