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
  19 #include <asm/neon.h>
  20 #include <asm/simd.h>
  21
  22 #define CRC_T10DIF_PMULL_CHUNK_SIZE     16U
  23
  24 asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 buf[], u32 len);
  25
  26 static int crct10dif_init(struct shash_desc *desc)
  27 {
  28         u16 *crc = shash_desc_ctx(desc);
  29
  30         *crc = 0;
  31         return 0;
  32 }
  33
  34 static int crct10dif_update(struct shash_desc *desc, const u8 *data,
  35                             unsigned int length)
  36 {
  37         u16 *crc = shash_desc_ctx(desc);
  38         unsigned int l;
  39
  40         if (!may_use_simd()) {
  41                 *crc = crc_t10dif_generic(*crc, data, length);
  42         } else {
  43                 if (unlikely((u32)data % CRC_T10DIF_PMULL_CHUNK_SIZE)) {
  44                         l = min_t(u32, length, CRC_T10DIF_PMULL_CHUNK_SIZE -
  45                                   ((u32)data % CRC_T10DIF_PMULL_CHUNK_SIZE));
  46
  47                         *crc = crc_t10dif_generic(*crc, data, l);
  48
  49                         length -= l;
  50                         data += l;
  51                 }
  52                 if (length > 0) {
  53                         kernel_neon_begin();
  54                         *crc = crc_t10dif_pmull(*crc, data, length);
  55                         kernel_neon_end();
  56                 }
  57         }
  58         return 0;
  59 }
  60
  61 static int crct10dif_final(struct shash_desc *desc, u8 *out)
  62 {
  63         u16 *crc = shash_desc_ctx(desc);
  64
  65         *(u16 *)out = *crc;
  66         return 0;
  67 }
  68
  69 static struct shash_alg crc_t10dif_alg = {
  70         .digestsize             = CRC_T10DIF_DIGEST_SIZE,
  71         .init                   = crct10dif_init,
  72         .update                 = crct10dif_update,
  73         .final                  = crct10dif_final,
  74         .descsize               = CRC_T10DIF_DIGEST_SIZE,
  75
  76         .base.cra_name          = "crct10dif",
  77         .base.cra_driver_name   = "crct10dif-arm-ce",
  78         .base.cra_priority      = 200,
  79         .base.cra_blocksize     = CRC_T10DIF_BLOCK_SIZE,
  80         .base.cra_module        = THIS_MODULE,
  81 };
  82
  83 static int __init crc_t10dif_mod_init(void)
  84 {
  85         if (!(elf_hwcap2 & HWCAP2_PMULL))
  86                 return -ENODEV;
  87
  88         return crypto_register_shash(&crc_t10dif_alg);
  89 }
  90
  91 static void __exit crc_t10dif_mod_exit(void)
  92 {
  93         crypto_unregister_shash(&crc_t10dif_alg);
  94 }
  95
  96 module_init(crc_t10dif_mod_init);
  97 module_exit(crc_t10dif_mod_exit);
  98
  99 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 100 MODULE_LICENSE("GPL v2");
 101 MODULE_ALIAS_CRYPTO("crct10dif");