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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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e7b3ed3380
The x86, arm, and arm64 asm implementations of crct10dif are very difficult to understand partly because many of the comments, labels, and macros are named incorrectly: the lengths mentioned are usually off by a factor of two from the actual code. Many other things are unnecessarily convoluted as well, e.g. there are many more fold constants than actually needed and some aren't fully reduced. This series therefore cleans up all these implementations to be much more maintainable. I also made some small optimizations where I saw opportunities, resulting in slightly better performance. This patch cleans up the arm version. (Also moved the constants to .rodata as suggested by Ard Biesheuvel.) Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
91 lines
2.1 KiB
C
91 lines
2.1 KiB
C
/*
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* Accelerated CRC-T10DIF using ARM 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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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/crc-t10dif.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/hash.h>
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#include <asm/neon.h>
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#include <asm/simd.h>
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#define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
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asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len);
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static int crct10dif_init(struct shash_desc *desc)
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{
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u16 *crc = shash_desc_ctx(desc);
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*crc = 0;
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return 0;
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}
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static int crct10dif_update(struct shash_desc *desc, const u8 *data,
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unsigned int length)
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{
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u16 *crc = shash_desc_ctx(desc);
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if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && may_use_simd()) {
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kernel_neon_begin();
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*crc = crc_t10dif_pmull(*crc, data, length);
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kernel_neon_end();
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} else {
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*crc = crc_t10dif_generic(*crc, data, length);
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}
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return 0;
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}
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static int crct10dif_final(struct shash_desc *desc, u8 *out)
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{
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u16 *crc = shash_desc_ctx(desc);
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*(u16 *)out = *crc;
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return 0;
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}
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static struct shash_alg crc_t10dif_alg = {
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.digestsize = CRC_T10DIF_DIGEST_SIZE,
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.init = crct10dif_init,
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.update = crct10dif_update,
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.final = crct10dif_final,
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.descsize = CRC_T10DIF_DIGEST_SIZE,
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.base.cra_name = "crct10dif",
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.base.cra_driver_name = "crct10dif-arm-ce",
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.base.cra_priority = 200,
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.base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
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.base.cra_module = THIS_MODULE,
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};
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static int __init crc_t10dif_mod_init(void)
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{
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if (!(elf_hwcap2 & HWCAP2_PMULL))
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return -ENODEV;
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return crypto_register_shash(&crc_t10dif_alg);
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}
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static void __exit crc_t10dif_mod_exit(void)
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{
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crypto_unregister_shash(&crc_t10dif_alg);
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}
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module_init(crc_t10dif_mod_init);
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module_exit(crc_t10dif_mod_exit);
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MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS_CRYPTO("crct10dif");
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