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

   1 /*
   2  * Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions instructions
   3  *
   4  * Copyright (C) 2016 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/crc-t10dif.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/string.h>
  16
  17 #include <crypto/internal/hash.h>
  18 #include <crypto/internal/simd.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(u16 init_crc, const u8 *buf, size_t len);
  26
  27 static int crct10dif_init(struct shash_desc *desc)
  28 {
  29         u16 *crc = shash_desc_ctx(desc);
  30
  31         *crc = 0;
  32         return 0;
  33 }
  34
  35 static int crct10dif_update(struct shash_desc *desc, const u8 *data,
  36                             unsigned int length)
  37 {
  38         u16 *crc = shash_desc_ctx(desc);
  39
  40         if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
  41                 kernel_neon_begin();
  42                 *crc = crc_t10dif_pmull(*crc, data, length);
  43                 kernel_neon_end();
  44         } else {
  45                 *crc = crc_t10dif_generic(*crc, data, length);
  46         }
  47
  48         return 0;
  49 }
  50
  51 static int crct10dif_final(struct shash_desc *desc, u8 *out)
  52 {
  53         u16 *crc = shash_desc_ctx(desc);
  54
  55         *(u16 *)out = *crc;
  56         return 0;
  57 }
  58
  59 static struct shash_alg crc_t10dif_alg = {
  60         .digestsize             = CRC_T10DIF_DIGEST_SIZE,
  61         .init                   = crct10dif_init,
  62         .update                 = crct10dif_update,
  63         .final                  = crct10dif_final,
  64         .descsize               = CRC_T10DIF_DIGEST_SIZE,
  65
  66         .base.cra_name          = "crct10dif",
  67         .base.cra_driver_name   = "crct10dif-arm-ce",
  68         .base.cra_priority      = 200,
  69         .base.cra_blocksize     = CRC_T10DIF_BLOCK_SIZE,
  70         .base.cra_module        = THIS_MODULE,
  71 };
  72
  73 static int __init crc_t10dif_mod_init(void)
  74 {
  75         if (!(elf_hwcap2 & HWCAP2_PMULL))
  76                 return -ENODEV;
  77
  78         return crypto_register_shash(&crc_t10dif_alg);
  79 }
  80
  81 static void __exit crc_t10dif_mod_exit(void)
  82 {
  83         crypto_unregister_shash(&crc_t10dif_alg);
  84 }
  85
  86 module_init(crc_t10dif_mod_init);
  87 module_exit(crc_t10dif_mod_exit);
  88
  89 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  90 MODULE_LICENSE("GPL v2");
  91 MODULE_ALIAS_CRYPTO("crct10dif");