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"); 152