arch/x86/crypto/crct10dif-pclmul_glue.c

   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/fpu/api.h>
  33 #include <asm/cpufeatures.h>
  34 #include <asm/cpu_device_id.h>
  35
  36 asmlinkage __u16 crc_t10dif_pcl(__u16 crc, const unsigned char *buf,
  37                                 size_t len);
  38
  39 struct 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
  48 static 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
  57 static 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
  71 static 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
  79 static 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
  91 static 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
  99 static 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
 107 static 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
 124 static const struct x86_cpu_id crct10dif_cpu_id[] = {
 125         X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ),
 126         {}
 127 };
 128 MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id);
 129
 130 static 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
 138 static void __exit crct10dif_intel_mod_fini(void)
 139 {
 140         crypto_unregister_shash(&alg);
 141 }
 142
 143 module_init(crct10dif_intel_mod_init);
 144 module_exit(crct10dif_intel_mod_fini);
 145
 146 MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>");
 147 MODULE_DESCRIPTION("T10 DIF CRC calculation accelerated with PCLMULQDQ.");
 148 MODULE_LICENSE("GPL");
 149
 150 MODULE_ALIAS_CRYPTO("crct10dif");
 151 MODULE_ALIAS_CRYPTO("crct10dif-pclmul");