LXR linux/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
  24asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 buf[], u32 len);
  25
  26static int crct10dif_init(struct shash_desc *desc)
  27{
  28        u16 *crc = shash_desc_ctx(desc);
  29
  30        *crc = 0;
  31        return 0;
  32}
  33
  34static 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
  61static 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
  69static 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
  83static 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
  91static void __exit crc_t10dif_mod_exit(void)
  92{
  93        crypto_unregister_shash(&crc_t10dif_alg);
  94}
  95
  96module_init(crc_t10dif_mod_init);
  97module_exit(crc_t10dif_mod_exit);
  98
  99MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 100MODULE_LICENSE("GPL v2");
 101MODULE_ALIAS_CRYPTO("crct10dif");
 102