1 /* 2 * Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions 3 * 4 * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <linux/cpufeature.h> 12 #include <linux/crc-t10dif.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/string.h> 17 18 #include <crypto/internal/hash.h> 19 20 #include <asm/neon.h> 21 22 #define CRC_T10DIF_PMULL_CHUNK_SIZE 16U 23 24 asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 buf[], u64 len); 25 26 static int crct10dif_init(struct shash_desc *desc) 27 { 28 u16 *crc = shash_desc_ctx(desc); 29 30 *crc = 0; 31 return 0; 32 } 33 34 static int crct10dif_update(struct shash_desc *desc, const u8 *data, 35 unsigned int length) 36 { 37 u16 *crc = shash_desc_ctx(desc); 38 unsigned int l; 39 40 if (unlikely((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE)) { 41 l = min_t(u32, length, CRC_T10DIF_PMULL_CHUNK_SIZE - 42 ((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE)); 43 44 *crc = crc_t10dif_generic(*crc, data, l); 45 46 length -= l; 47 data += l; 48 } 49 50 if (length > 0) { 51 kernel_neon_begin_partial(14); 52 *crc = crc_t10dif_pmull(*crc, data, length); 53 kernel_neon_end(); 54 } 55 56 return 0; 57 } 58 59 static int crct10dif_final(struct shash_desc *desc, u8 *out) 60 { 61 u16 *crc = shash_desc_ctx(desc); 62 63 *(u16 *)out = *crc; 64 return 0; 65 } 66 67 static struct shash_alg crc_t10dif_alg = { 68 .digestsize = CRC_T10DIF_DIGEST_SIZE, 69 .init = crct10dif_init, 70 .update = crct10dif_update, 71 .final = crct10dif_final, 72 .descsize = CRC_T10DIF_DIGEST_SIZE, 73 74 .base.cra_name = "crct10dif", 75 .base.cra_driver_name = "crct10dif-arm64-ce", 76 .base.cra_priority = 200, 77 .base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE, 78 .base.cra_module = THIS_MODULE, 79 }; 80 81 static int __init crc_t10dif_mod_init(void) 82 { 83 return crypto_register_shash(&crc_t10dif_alg); 84 } 85 86 static void __exit crc_t10dif_mod_exit(void) 87 { 88 crypto_unregister_shash(&crc_t10dif_alg); 89 } 90 91 module_cpu_feature_match(PMULL, crc_t10dif_mod_init); 92 module_exit(crc_t10dif_mod_exit); 93 94 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); 95 MODULE_LICENSE("GPL v2"); 96