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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions instructions
   4  *
   5  * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
   6  */
   7
   8 #include <linux/crc-t10dif.h>
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/string.h>
  13
  14 #include <crypto/internal/hash.h>
  15 #include <crypto/internal/simd.h>
  16
  17 #include <asm/neon.h>
  18 #include <asm/simd.h>
  19
  20 #define CRC_T10DIF_PMULL_CHUNK_SIZE     16U
  21
  22 asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len);
  23
  24 static int crct10dif_init(struct shash_desc *desc)
  25 {
  26         u16 *crc = shash_desc_ctx(desc);
  27
  28         *crc = 0;
  29         return 0;
  30 }
  31
  32 static int crct10dif_update(struct shash_desc *desc, const u8 *data,
  33                             unsigned int length)
  34 {
  35         u16 *crc = shash_desc_ctx(desc);
  36
  37         if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
  38                 kernel_neon_begin();
  39                 *crc = crc_t10dif_pmull(*crc, data, length);
  40                 kernel_neon_end();
  41         } else {
  42                 *crc = crc_t10dif_generic(*crc, data, length);
  43         }
  44
  45         return 0;
  46 }
  47
  48 static int crct10dif_final(struct shash_desc *desc, u8 *out)
  49 {
  50         u16 *crc = shash_desc_ctx(desc);
  51
  52         *(u16 *)out = *crc;
  53         return 0;
  54 }
  55
  56 static struct shash_alg crc_t10dif_alg = {
  57         .digestsize             = CRC_T10DIF_DIGEST_SIZE,
  58         .init                   = crct10dif_init,
  59         .update                 = crct10dif_update,
  60         .final                  = crct10dif_final,
  61         .descsize               = CRC_T10DIF_DIGEST_SIZE,
  62
  63         .base.cra_name          = "crct10dif",
  64         .base.cra_driver_name   = "crct10dif-arm-ce",
  65         .base.cra_priority      = 200,
  66         .base.cra_blocksize     = CRC_T10DIF_BLOCK_SIZE,
  67         .base.cra_module        = THIS_MODULE,
  68 };
  69
  70 static int __init crc_t10dif_mod_init(void)
  71 {
  72         if (!(elf_hwcap2 & HWCAP2_PMULL))
  73                 return -ENODEV;
  74
  75         return crypto_register_shash(&crc_t10dif_alg);
  76 }
  77
  78 static void __exit crc_t10dif_mod_exit(void)
  79 {
  80         crypto_unregister_shash(&crc_t10dif_alg);
  81 }
  82
  83 module_init(crc_t10dif_mod_init);
  84 module_exit(crc_t10dif_mod_exit);
  85
  86 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  87 MODULE_LICENSE("GPL v2");
  88 MODULE_ALIAS_CRYPTO("crct10dif");