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 init_crc, const u8 *buf, size_t len); 37 38 struct chksum_desc_ctx { 39 __u16 crc; 40 }; 41 42 static int chksum_init(struct shash_desc *desc) 43 { 44 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); 45 46 ctx->crc = 0; 47 48 return 0; 49 } 50 51 static int chksum_update(struct shash_desc *desc, const u8 *data, 52 unsigned int length) 53 { 54 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); 55 56 if (length >= 16 && irq_fpu_usable()) { 57 kernel_fpu_begin(); 58 ctx->crc = crc_t10dif_pcl(ctx->crc, data, length); 59 kernel_fpu_end(); 60 } else 61 ctx->crc = crc_t10dif_generic(ctx->crc, data, length); 62 return 0; 63 } 64 65 static int chksum_final(struct shash_desc *desc, u8 *out) 66 { 67 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); 68 69 *(__u16 *)out = ctx->crc; 70 return 0; 71 } 72 73 static int __chksum_finup(__u16 *crcp, const u8 *data, unsigned int len, 74 u8 *out) 75 { 76 if (len >= 16 && irq_fpu_usable()) { 77 kernel_fpu_begin(); 78 *(__u16 *)out = crc_t10dif_pcl(*crcp, data, len); 79 kernel_fpu_end(); 80 } else 81 *(__u16 *)out = crc_t10dif_generic(*crcp, 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 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); 97 98 return __chksum_finup(&ctx->crc, data, length, out); 99 } 100 101 static struct shash_alg alg = { 102 .digestsize = CRC_T10DIF_DIGEST_SIZE, 103 .init = chksum_init, 104 .update = chksum_update, 105 .final = chksum_final, 106 .finup = chksum_finup, 107 .digest = chksum_digest, 108 .descsize = sizeof(struct chksum_desc_ctx), 109 .base = { 110 .cra_name = "crct10dif", 111 .cra_driver_name = "crct10dif-pclmul", 112 .cra_priority = 200, 113 .cra_blocksize = CRC_T10DIF_BLOCK_SIZE, 114 .cra_module = THIS_MODULE, 115 } 116 }; 117 118 static const struct x86_cpu_id crct10dif_cpu_id[] = { 119 X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), 120 {} 121 }; 122 MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id); 123 124 static int __init crct10dif_intel_mod_init(void) 125 { 126 if (!x86_match_cpu(crct10dif_cpu_id)) 127 return -ENODEV; 128 129 return crypto_register_shash(&alg); 130 } 131 132 static void __exit crct10dif_intel_mod_fini(void) 133 { 134 crypto_unregister_shash(&alg); 135 } 136 137 module_init(crct10dif_intel_mod_init); 138 module_exit(crct10dif_intel_mod_fini); 139 140 MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>"); 141 MODULE_DESCRIPTION("T10 DIF CRC calculation accelerated with PCLMULQDQ."); 142 MODULE_LICENSE("GPL"); 143 144 MODULE_ALIAS_CRYPTO("crct10dif"); 145 MODULE_ALIAS_CRYPTO("crct10dif-pclmul"); 146