arch/arm64/crypto/crct10dif-ce-glue.c

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