LXR linux/arch/x86/crypto/crct10dif-pclmul

   1/*
   2 * Cryptographic API.
   3 *
   4 * T10 Data Integrity Field CRC16 Crypto Transform using PCLMULQDQ Instructions
   5 *
   6 * Copyright (C) 2013 Intel Corporation
   7 * Author: Tim Chen <tim.c.chen@linux.intel.com>
   8 *
   9 * This program is free software; you can redistribute it and/or modify it
  10 * under the terms of the GNU General Public License as published by the Free
  11 * Software Foundation; either version 2 of the License, or (at your option)
  12 * any later version.
  13 *
  14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  17 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  18 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  19 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  20 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21 * SOFTWARE.
  22 *
  23 */
  24
  25#include <linux/types.h>
  26#include <linux/module.h>
  27#include <linux/crc-t10dif.h>
  28#include <crypto/internal/hash.h>
  29#include <crypto/internal/simd.h>
  30#include <linux/init.h>
  31#include <linux/string.h>
  32#include <linux/kernel.h>
  33#include <asm/cpufeatures.h>
  34#include <asm/cpu_device_id.h>
  35#include <asm/simd.h>
  36
  37asmlinkage u16 crc_t10dif_pcl(u16 init_crc, const u8 *buf, size_t len);
  38
  39struct chksum_desc_ctx {
  40        __u16 crc;
  41};
  42
  43static int chksum_init(struct shash_desc *desc)
  44{
  45        struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  46
  47        ctx->crc = 0;
  48
  49        return 0;
  50}
  51
  52static int chksum_update(struct shash_desc *desc, const u8 *data,
  53                         unsigned int length)
  54{
  55        struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  56
  57        if (length >= 16 && crypto_simd_usable()) {
  58                kernel_fpu_begin();
  59                ctx->crc = crc_t10dif_pcl(ctx->crc, data, length);
  60                kernel_fpu_end();
  61        } else
  62                ctx->crc = crc_t10dif_generic(ctx->crc, data, length);
  63        return 0;
  64}
  65
  66static int chksum_final(struct shash_desc *desc, u8 *out)
  67{
  68        struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  69
  70        *(__u16 *)out = ctx->crc;
  71        return 0;
  72}
  73
  74static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)
  75{
  76        if (len >= 16 && crypto_simd_usable()) {
  77                kernel_fpu_begin();
  78                *(__u16 *)out = crc_t10dif_pcl(crc, data, len);
  79                kernel_fpu_end();
  80        } else
  81                *(__u16 *)out = crc_t10dif_generic(crc, data, len);
  82        return 0;
  83}
  84
  85static int chksum_finup(struct shash_desc *desc, const u8 *data,
  86                        unsigned int len, u8 *out)
  87{
  88        struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  89
  90        return __chksum_finup(ctx->crc, data, len, out);
  91}
  92
  93static int chksum_digest(struct shash_desc *desc, const u8 *data,
  94                         unsigned int length, u8 *out)
  95{
  96        return __chksum_finup(0, data, length, out);
  97}
  98
  99static struct shash_alg alg = {
 100        .digestsize             =       CRC_T10DIF_DIGEST_SIZE,
 101        .init           =       chksum_init,
 102        .update         =       chksum_update,
 103        .final          =       chksum_final,
 104        .finup          =       chksum_finup,
 105        .digest         =       chksum_digest,
 106        .descsize               =       sizeof(struct chksum_desc_ctx),
 107        .base                   =       {
 108                .cra_name               =       "crct10dif",
 109                .cra_driver_name        =       "crct10dif-pclmul",
 110                .cra_priority           =       200,
 111                .cra_blocksize          =       CRC_T10DIF_BLOCK_SIZE,
 112                .cra_module             =       THIS_MODULE,
 113        }
 114};
 115
 116static const struct x86_cpu_id crct10dif_cpu_id[] = {
 117        X86_MATCH_FEATURE(X86_FEATURE_PCLMULQDQ, NULL),
 118        {}
 119};
 120MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id);
 121
 122static int __init crct10dif_intel_mod_init(void)
 123{
 124        if (!x86_match_cpu(crct10dif_cpu_id))
 125                return -ENODEV;
 126
 127        return crypto_register_shash(&alg);
 128}
 129
 130static void __exit crct10dif_intel_mod_fini(void)
 131{
 132        crypto_unregister_shash(&alg);
 133}
 134
 135module_init(crct10dif_intel_mod_init);
 136module_exit(crct10dif_intel_mod_fini);
 137
 138MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>");
 139MODULE_DESCRIPTION("T10 DIF CRC calculation accelerated with PCLMULQDQ.");
 140MODULE_LICENSE("GPL");
 141
 142MODULE_ALIAS_CRYPTO("crct10dif");
 143MODULE_ALIAS_CRYPTO("crct10dif-pclmul");
 144