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(u16 init_crc, const u8 buf[], u64 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         unsigned int l;
  40
  41         if (unlikely((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE)) {
  42                 l = min_t(u32, length, CRC_T10DIF_PMULL_CHUNK_SIZE -
  43                           ((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE));
  44
  45                 *crc = crc_t10dif_generic(*crc, data, l);
  46
  47                 length -= l;
  48                 data += l;
  49         }
  50
  51         if (length > 0) {
  52                 if (may_use_simd()) {
  53                         kernel_neon_begin();
  54                         *crc = crc_t10dif_pmull(*crc, data, length);
  55                         kernel_neon_end();
  56                 } else {
  57                         *crc = crc_t10dif_generic(*crc, data, length);
  58                 }
  59         }
  60
  61         return 0;
  62 }
  63
  64 static int crct10dif_final(struct shash_desc *desc, u8 *out)
  65 {
  66         u16 *crc = shash_desc_ctx(desc);
  67
  68         *(u16 *)out = *crc;
  69         return 0;
  70 }
  71
  72 static struct shash_alg crc_t10dif_alg = {
  73         .digestsize             = CRC_T10DIF_DIGEST_SIZE,
  74         .init                   = crct10dif_init,
  75         .update                 = crct10dif_update,
  76         .final                  = crct10dif_final,
  77         .descsize               = CRC_T10DIF_DIGEST_SIZE,
  78
  79         .base.cra_name          = "crct10dif",
  80         .base.cra_driver_name   = "crct10dif-arm64-ce",
  81         .base.cra_priority      = 200,
  82         .base.cra_blocksize     = CRC_T10DIF_BLOCK_SIZE,
  83         .base.cra_module        = THIS_MODULE,
  84 };
  85
  86 static int __init crc_t10dif_mod_init(void)
  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_cpu_feature_match(PMULL, 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");