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 <linux/init.h>
  30#include <linux/string.h>
  31#include <linux/kernel.h>
  32#include <asm/i387.h>
  33#include <asm/cpufeature.h>
  34#include <asm/cpu_device_id.h>
  35
  36asmlinkage __u16 crc_t10dif_pcl(__u16 crc, const unsigned char *buf,
  37                                size_t len);
  38
  39struct chksum_desc_ctx {
  40        __u16 crc;
  41};
  42
  43/*
  44 * Steps through buffer one byte at at time, calculates reflected
  45 * crc using table.
  46 */
  47
  48static int chksum_init(struct shash_desc *desc)
  49{
  50        struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  51
  52        ctx->crc = 0;
  53
  54        return 0;
  55}
  56
  57static int chksum_update(struct shash_desc *desc, const u8 *data,
  58                         unsigned int length)
  59{
  60        struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  61
  62        if (irq_fpu_usable()) {
  63                kernel_fpu_begin();
  64                ctx->crc = crc_t10dif_pcl(ctx->crc, data, length);
  65                kernel_fpu_end();
  66        } else
  67                ctx->crc = crc_t10dif_generic(ctx->crc, data, length);
  68        return 0;
  69}
  70
  71static int chksum_final(struct shash_desc *desc, u8 *out)
  72{
  73        struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  74
  75        *(__u16 *)out = ctx->crc;
  76        return 0;
  77}
  78
  79static int __chksum_finup(__u16 *crcp, const u8 *data, unsigned int len,
  80                        u8 *out)
  81{
  82        if (irq_fpu_usable()) {
  83                kernel_fpu_begin();
  84                *(__u16 *)out = crc_t10dif_pcl(*crcp, data, len);
  85                kernel_fpu_end();
  86        } else
  87                *(__u16 *)out = crc_t10dif_generic(*crcp, data, len);
  88        return 0;
  89}
  90
  91static int chksum_finup(struct shash_desc *desc, const u8 *data,
  92                        unsigned int len, u8 *out)
  93{
  94        struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  95
  96        return __chksum_finup(&ctx->crc, data, len, out);
  97}
  98
  99static int chksum_digest(struct shash_desc *desc, const u8 *data,
 100                         unsigned int length, u8 *out)
 101{
 102        struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
 103
 104        return __chksum_finup(&ctx->crc, data, length, out);
 105}
 106
 107static struct shash_alg alg = {
 108        .digestsize             =       CRC_T10DIF_DIGEST_SIZE,
 109        .init           =       chksum_init,
 110        .update         =       chksum_update,
 111        .final          =       chksum_final,
 112        .finup          =       chksum_finup,
 113        .digest         =       chksum_digest,
 114        .descsize               =       sizeof(struct chksum_desc_ctx),
 115        .base                   =       {
 116                .cra_name               =       "crct10dif",
 117                .cra_driver_name        =       "crct10dif-pclmul",
 118                .cra_priority           =       200,
 119                .cra_blocksize          =       CRC_T10DIF_BLOCK_SIZE,
 120                .cra_module             =       THIS_MODULE,
 121        }
 122};
 123
 124static const struct x86_cpu_id crct10dif_cpu_id[] = {
 125        X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ),
 126        {}
 127};
 128MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id);
 129
 130static int __init crct10dif_intel_mod_init(void)
 131{
 132        if (!x86_match_cpu(crct10dif_cpu_id))
 133                return -ENODEV;
 134
 135        return crypto_register_shash(&alg);
 136}
 137
 138static void __exit crct10dif_intel_mod_fini(void)
 139{
 140        crypto_unregister_shash(&alg);
 141}
 142
 143module_init(crct10dif_intel_mod_init);
 144module_exit(crct10dif_intel_mod_fini);
 145
 146MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>");
 147MODULE_DESCRIPTION("T10 DIF CRC calculation accelerated with PCLMULQDQ.");
 148MODULE_LICENSE("GPL");
 149
 150MODULE_ALIAS("crct10dif");
 151MODULE_ALIAS("crct10dif-pclmul");
 152