diff options
author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-20 20:42:41 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-20 20:42:41 +0300 |
commit | 5c40cd7db64a2949f268d7467b9be551a565d14b (patch) | |
tree | fb8a67f6edcb0c9922c256a598d675c1c04051d6 /arch/arm/lib/crc32.c | |
parent | 8bde384a2090759efc9b92f34300887d418a2a3a (diff) | |
parent | 25bf10be219d37d2fb221c93816a913f5f735530 (diff) | |
download | linux-rolling-stable.tar.xz |
Merge v6.16.2linux-rolling-stable
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/lib/crc32.c')
-rw-r--r-- | arch/arm/lib/crc32.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/arm/lib/crc32.c b/arch/arm/lib/crc32.c new file mode 100644 index 000000000000..f2bef8849c7c --- /dev/null +++ b/arch/arm/lib/crc32.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions instructions + * + * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> + */ + +#include <linux/cpufeature.h> +#include <linux/crc32.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/string.h> + +#include <crypto/internal/simd.h> + +#include <asm/hwcap.h> +#include <asm/neon.h> +#include <asm/simd.h> + +static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_crc32); +static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_pmull); + +#define PMULL_MIN_LEN 64 /* min size of buffer for pmull functions */ + +asmlinkage u32 crc32_pmull_le(const u8 buf[], u32 len, u32 init_crc); +asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], u32 len); + +asmlinkage u32 crc32c_pmull_le(const u8 buf[], u32 len, u32 init_crc); +asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], u32 len); + +static u32 crc32_le_scalar(u32 crc, const u8 *p, size_t len) +{ + if (static_branch_likely(&have_crc32)) + return crc32_armv8_le(crc, p, len); + return crc32_le_base(crc, p, len); +} + +u32 crc32_le_arch(u32 crc, const u8 *p, size_t len) +{ + if (len >= PMULL_MIN_LEN + 15 && + static_branch_likely(&have_pmull) && crypto_simd_usable()) { + size_t n = -(uintptr_t)p & 15; + + /* align p to 16-byte boundary */ + if (n) { + crc = crc32_le_scalar(crc, p, n); + p += n; + len -= n; + } + n = round_down(len, 16); + kernel_neon_begin(); + crc = crc32_pmull_le(p, n, crc); + kernel_neon_end(); + p += n; + len -= n; + } + return crc32_le_scalar(crc, p, len); +} +EXPORT_SYMBOL(crc32_le_arch); + +static u32 crc32c_scalar(u32 crc, const u8 *p, size_t len) +{ + if (static_branch_likely(&have_crc32)) + return crc32c_armv8_le(crc, p, len); + return crc32c_base(crc, p, len); +} + +u32 crc32c_arch(u32 crc, const u8 *p, size_t len) +{ + if (len >= PMULL_MIN_LEN + 15 && + static_branch_likely(&have_pmull) && crypto_simd_usable()) { + size_t n = -(uintptr_t)p & 15; + + /* align p to 16-byte boundary */ + if (n) { + crc = crc32c_scalar(crc, p, n); + p += n; + len -= n; + } + n = round_down(len, 16); + kernel_neon_begin(); + crc = crc32c_pmull_le(p, n, crc); + kernel_neon_end(); + p += n; + len -= n; + } + return crc32c_scalar(crc, p, len); +} +EXPORT_SYMBOL(crc32c_arch); + +u32 crc32_be_arch(u32 crc, const u8 *p, size_t len) +{ + return crc32_be_base(crc, p, len); +} +EXPORT_SYMBOL(crc32_be_arch); + +static int __init crc32_arm_init(void) +{ + if (elf_hwcap2 & HWCAP2_CRC32) + static_branch_enable(&have_crc32); + if (elf_hwcap2 & HWCAP2_PMULL) + static_branch_enable(&have_pmull); + return 0; +} +subsys_initcall(crc32_arm_init); + +static void __exit crc32_arm_exit(void) +{ +} +module_exit(crc32_arm_exit); + +u32 crc32_optimizations(void) +{ + if (elf_hwcap2 & (HWCAP2_CRC32 | HWCAP2_PMULL)) + return CRC32_LE_OPTIMIZATION | CRC32C_OPTIMIZATION; + return 0; +} +EXPORT_SYMBOL(crc32_optimizations); + +MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); +MODULE_DESCRIPTION("Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions"); +MODULE_LICENSE("GPL v2"); |