1 /* 2 * Accelerated CRC-T10DIF using ARM 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/crc-t10dif.h> 12 #include <linux/init.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/string.h> 16 17 #include <crypto/internal/hash.h> 18 #include <crypto/internal/simd.h> 19 20 #include <asm/neon.h> 21 #include <asm/simd.h> 22 23 #define CRC_T10DIF_PMULL_CHUNK_SIZE 16U 24 25 asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len); 26 27 static int crct10dif_init(struct shash_desc *desc) 28 { 29 u16 *crc = shash_desc_ctx(desc); 30 31 *crc = 0; 32 return 0; 33 } 34 35 static int crct10dif_update(struct shash_desc *desc, const u8 *data, 36 unsigned int length) 37 { 38 u16 *crc = shash_desc_ctx(desc); 39 40 if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) { 41 kernel_neon_begin(); 42 *crc = crc_t10dif_pmull(*crc, data, length); 43 kernel_neon_end(); 44 } else { 45 *crc = crc_t10dif_generic(*crc, data, length); 46 } 47 48 return 0; 49 } 50 51 static int crct10dif_final(struct shash_desc *desc, u8 *out) 52 { 53 u16 *crc = shash_desc_ctx(desc); 54 55 *(u16 *)out = *crc; 56 return 0; 57 } 58 59 static struct shash_alg crc_t10dif_alg = { 60 .digestsize = CRC_T10DIF_DIGEST_SIZE, 61 .init = crct10dif_init, 62 .update = crct10dif_update, 63 .final = crct10dif_final, 64 .descsize = CRC_T10DIF_DIGEST_SIZE, 65 66 .base.cra_name = "crct10dif", 67 .base.cra_driver_name = "crct10dif-arm-ce", 68 .base.cra_priority = 200, 69 .base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE, 70 .base.cra_module = THIS_MODULE, 71 }; 72 73 static int __init crc_t10dif_mod_init(void) 74 { 75 if (!(elf_hwcap2 & HWCAP2_PMULL)) 76 return -ENODEV; 77 78 return crypto_register_shash(&crc_t10dif_alg); 79 } 80 81 static void __exit crc_t10dif_mod_exit(void) 82 { 83 crypto_unregister_shash(&crc_t10dif_alg); 84 } 85 86 module_init(crc_t10dif_mod_init); 87 module_exit(crc_t10dif_mod_exit); 88 89 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); 90 MODULE_LICENSE("GPL v2"); 91 MODULE_ALIAS_CRYPTO("crct10dif"); 92