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

   1 /*
   2  * Accelerated CRC-T10DIF using arm64 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/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
  22 #define CRC_T10DIF_PMULL_CHUNK_SIZE     16U
  23
  24 asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 buf[], u64 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 (unlikely((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE)) {
  41                 l = min_t(u32, length, CRC_T10DIF_PMULL_CHUNK_SIZE -
  42                           ((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE));
  43
  44                 *crc = crc_t10dif_generic(*crc, data, l);
  45
  46                 length -= l;
  47                 data += l;
  48         }
  49
  50         if (length > 0) {
  51                 kernel_neon_begin_partial(14);
  52                 *crc = crc_t10dif_pmull(*crc, data, length);
  53                 kernel_neon_end();
  54         }
  55
  56         return 0;
  57 }
  58
  59 static int crct10dif_final(struct shash_desc *desc, u8 *out)
  60 {
  61         u16 *crc = shash_desc_ctx(desc);
  62
  63         *(u16 *)out = *crc;
  64         return 0;
  65 }
  66
  67 static struct shash_alg crc_t10dif_alg = {
  68         .digestsize             = CRC_T10DIF_DIGEST_SIZE,
  69         .init                   = crct10dif_init,
  70         .update                 = crct10dif_update,
  71         .final                  = crct10dif_final,
  72         .descsize               = CRC_T10DIF_DIGEST_SIZE,
  73
  74         .base.cra_name          = "crct10dif",
  75         .base.cra_driver_name   = "crct10dif-arm64-ce",
  76         .base.cra_priority      = 200,
  77         .base.cra_blocksize     = CRC_T10DIF_BLOCK_SIZE,
  78         .base.cra_module        = THIS_MODULE,
  79 };
  80
  81 static int __init crc_t10dif_mod_init(void)
  82 {
  83         return crypto_register_shash(&crc_t10dif_alg);
  84 }
  85
  86 static void __exit crc_t10dif_mod_exit(void)
  87 {
  88         crypto_unregister_shash(&crc_t10dif_alg);
  89 }
  90
  91 module_cpu_feature_match(PMULL, crc_t10dif_mod_init);
  92 module_exit(crc_t10dif_mod_exit);
  93
  94 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  95 MODULE_LICENSE("GPL v2");