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git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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648c7fb16f
Make the architecture-optimized CRC code do its CPU feature checks in subsys_initcalls instead of arch_initcalls. This makes it consistent with arch/*/lib/crypto/ and ensures that it runs after initcalls that possibly could be a prerequisite for kernel-mode FPU, such as x86's xfd_update_static_branch() and loongarch's init_euen_mask(). Note: as far as I can tell, x86's xfd_update_static_branch() isn't *actually* needed for kernel-mode FPU. loongarch's init_euen_mask() is needed to enable save/restore of the vector registers, but loongarch doesn't yet have any CRC or crypto code that uses vector registers anyway. Regardless, let's be consistent with arch/*/lib/crypto/ and robust against any potential future dependency on an arch_initcall. Link: https://lore.kernel.org/r/20250510035959.87995-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
124 lines
3.0 KiB
C
124 lines
3.0 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 __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 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_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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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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EXPORT_SYMBOL(crc32c_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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subsys_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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