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530b304f00
Move the arm-optimized CRC code from arch/arm/lib/crc* into its new location in lib/crc/arm/, and wire it up in the new way. This new way of organizing the CRC code eliminates the need to artificially split the code for each CRC variant into separate arch and generic modules, enabling better inlining and dead code elimination. For more details, see "lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/". Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20250607200454.73587-4-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
101 lines
2.6 KiB
C
101 lines
2.6 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 <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 __ro_after_init DEFINE_STATIC_KEY_FALSE(have_crc32);
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static __ro_after_init 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 inline 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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static inline 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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static inline u32 crc32c_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_base(crc, p, len);
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}
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static inline u32 crc32c_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_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_scalar(crc, p, len);
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}
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#define crc32_be_arch crc32_be_base /* not implemented on this arch */
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#define crc32_mod_init_arch crc32_mod_init_arch
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static inline void crc32_mod_init_arch(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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}
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static inline u32 crc32_optimizations_arch(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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