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 37 asmlinkage u16 crc_t10dif_pcl(u16 init_crc, const u8 *buf, size_t len); 38 39 struct chksum_desc_ctx { 40 __u16 crc; 41 }; 42 43 static 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 52 static 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 66 static 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 74 static 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 85 static 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 93 static 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 99 static 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 }; 115 116 static const struct x86_cpu_id crct10dif_cpu_id[] = { 117 X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), 118 {} 119 }; 120 MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id); 121 122 static 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 } 129 130 static void __exit crct10dif_intel_mod_fini(void) 131 { 132 crypto_unregister_shash(&alg); 133 } 134 135 module_init(crct10dif_intel_mod_init); 136 module_exit(crct10dif_intel_mod_fini); 137 138 MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>"); 139 MODULE_DESCRIPTION("T10 DIF CRC calculation accelerated with PCLMULQDQ."); 140 MODULE_LICENSE("GPL"); 141 142 MODULE_ALIAS_CRYPTO("crct10dif"); 143 MODULE_ALIAS_CRYPTO("crct10dif-pclmul"); 144