linux/arch/arm64/crypto/crct10dif-ce-glue.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions
   4 *
   5 * Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
   6 */
   7
   8#include <linux/cpufeature.h>
   9#include <linux/crc-t10dif.h>
  10#include <linux/init.h>
  11#include <linux/kernel.h>
  12#include <linux/module.h>
  13#include <linux/string.h>
  14
  15#include <crypto/internal/hash.h>
  16#include <crypto/internal/simd.h>
  17
  18#include <asm/neon.h>
  19#include <asm/simd.h>
  20
  21#define CRC_T10DIF_PMULL_CHUNK_SIZE     16U
  22
  23asmlinkage u16 crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len);
  24asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len);
  25
  26static int crct10dif_init(struct shash_desc *desc)
  27{
  28        u16 *crc = shash_desc_ctx(desc);
  29
  30        *crc = 0;
  31        return 0;
  32}
  33
  34static int crct10dif_update_pmull_p8(struct shash_desc *desc, const u8 *data,
  35                            unsigned int length)
  36{
  37        u16 *crc = shash_desc_ctx(desc);
  38
  39        if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
  40                do {
  41                        unsigned int chunk = length;
  42
  43                        if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
  44                                chunk = SZ_4K;
  45
  46                        kernel_neon_begin();
  47                        *crc = crc_t10dif_pmull_p8(*crc, data, chunk);
  48                        kernel_neon_end();
  49                        data += chunk;
  50                        length -= chunk;
  51                } while (length);
  52        } else {
  53                *crc = crc_t10dif_generic(*crc, data, length);
  54        }
  55
  56        return 0;
  57}
  58
  59static int crct10dif_update_pmull_p64(struct shash_desc *desc, const u8 *data,
  60                            unsigned int length)
  61{
  62        u16 *crc = shash_desc_ctx(desc);
  63
  64        if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
  65                do {
  66                        unsigned int chunk = length;
  67
  68                        if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
  69                                chunk = SZ_4K;
  70
  71                        kernel_neon_begin();
  72                        *crc = crc_t10dif_pmull_p64(*crc, data, chunk);
  73                        kernel_neon_end();
  74                        data += chunk;
  75                        length -= chunk;
  76                } while (length);
  77        } else {
  78                *crc = crc_t10dif_generic(*crc, data, length);
  79        }
  80
  81        return 0;
  82}
  83
  84static int crct10dif_final(struct shash_desc *desc, u8 *out)
  85{
  86        u16 *crc = shash_desc_ctx(desc);
  87
  88        *(u16 *)out = *crc;
  89        return 0;
  90}
  91
  92static struct shash_alg crc_t10dif_alg[] = {{
  93        .digestsize             = CRC_T10DIF_DIGEST_SIZE,
  94        .init                   = crct10dif_init,
  95        .update                 = crct10dif_update_pmull_p8,
  96        .final                  = crct10dif_final,
  97        .descsize               = CRC_T10DIF_DIGEST_SIZE,
  98
  99        .base.cra_name          = "crct10dif",
 100        .base.cra_driver_name   = "crct10dif-arm64-neon",
 101        .base.cra_priority      = 100,
 102        .base.cra_blocksize     = CRC_T10DIF_BLOCK_SIZE,
 103        .base.cra_module        = THIS_MODULE,
 104}, {
 105        .digestsize             = CRC_T10DIF_DIGEST_SIZE,
 106        .init                   = crct10dif_init,
 107        .update                 = crct10dif_update_pmull_p64,
 108        .final                  = crct10dif_final,
 109        .descsize               = CRC_T10DIF_DIGEST_SIZE,
 110
 111        .base.cra_name          = "crct10dif",
 112        .base.cra_driver_name   = "crct10dif-arm64-ce",
 113        .base.cra_priority      = 200,
 114        .base.cra_blocksize     = CRC_T10DIF_BLOCK_SIZE,
 115        .base.cra_module        = THIS_MODULE,
 116}};
 117
 118static int __init crc_t10dif_mod_init(void)
 119{
 120        if (cpu_have_named_feature(PMULL))
 121                return crypto_register_shashes(crc_t10dif_alg,
 122                                               ARRAY_SIZE(crc_t10dif_alg));
 123        else
 124                /* only register the first array element */
 125                return crypto_register_shash(crc_t10dif_alg);
 126}
 127
 128static void __exit crc_t10dif_mod_exit(void)
 129{
 130        if (cpu_have_named_feature(PMULL))
 131                crypto_unregister_shashes(crc_t10dif_alg,
 132                                          ARRAY_SIZE(crc_t10dif_alg));
 133        else
 134                crypto_unregister_shash(crc_t10dif_alg);
 135}
 136
 137module_cpu_feature_match(ASIMD, crc_t10dif_mod_init);
 138module_exit(crc_t10dif_mod_exit);
 139
 140MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 141MODULE_LICENSE("GPL v2");
 142MODULE_ALIAS_CRYPTO("crct10dif");
 143MODULE_ALIAS_CRYPTO("crct10dif-arm64-ce");
 144