1/** 2 * AES routines supporting VMX instructions on the Power 8 3 * 4 * Copyright (C) 2015 International Business Machines Inc. 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 as published by 8 * the Free Software Foundation; version 2 only. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 18 * 19 * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com> 20 */ 21 22#include <linux/types.h> 23#include <linux/err.h> 24#include <linux/crypto.h> 25#include <linux/delay.h> 26#include <linux/hardirq.h> 27#include <asm/switch_to.h> 28#include <crypto/aes.h> 29 30#include "aesp8-ppc.h" 31 32struct p8_aes_ctx { 33 struct crypto_cipher *fallback; 34 struct aes_key enc_key; 35 struct aes_key dec_key; 36}; 37 38static int p8_aes_init(struct crypto_tfm *tfm) 39{ 40 const char *alg; 41 struct crypto_cipher *fallback; 42 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 43 44 if (!(alg = crypto_tfm_alg_name(tfm))) { 45 printk(KERN_ERR "Failed to get algorithm name.\n"); 46 return -ENOENT; 47 } 48 49 fallback = crypto_alloc_cipher(alg, 0 ,CRYPTO_ALG_NEED_FALLBACK); 50 if (IS_ERR(fallback)) { 51 printk(KERN_ERR "Failed to allocate transformation for '%s': %ld\n", 52 alg, PTR_ERR(fallback)); 53 return PTR_ERR(fallback); 54 } 55 printk(KERN_INFO "Using '%s' as fallback implementation.\n", 56 crypto_tfm_alg_driver_name((struct crypto_tfm *) fallback)); 57 58 crypto_cipher_set_flags(fallback, 59 crypto_cipher_get_flags((struct crypto_cipher *) tfm)); 60 ctx->fallback = fallback; 61 62 return 0; 63} 64 65static void p8_aes_exit(struct crypto_tfm *tfm) 66{ 67 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 68 69 if (ctx->fallback) { 70 crypto_free_cipher(ctx->fallback); 71 ctx->fallback = NULL; 72 } 73} 74 75static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key, 76 unsigned int keylen) 77{ 78 int ret; 79 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 80 81 pagefault_disable(); 82 enable_kernel_altivec(); 83 enable_kernel_vsx(); 84 ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key); 85 ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key); 86 pagefault_enable(); 87 88 ret += crypto_cipher_setkey(ctx->fallback, key, keylen); 89 return ret; 90} 91 92static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) 93{ 94 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 95 96 if (in_interrupt()) { 97 crypto_cipher_encrypt_one(ctx->fallback, dst, src); 98 } else { 99 pagefault_disable(); 100 enable_kernel_altivec(); 101 enable_kernel_vsx(); 102 aes_p8_encrypt(src, dst, &ctx->enc_key); 103 pagefault_enable(); 104 } 105} 106 107static void p8_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) 108{ 109 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 110 111 if (in_interrupt()) { 112 crypto_cipher_decrypt_one(ctx->fallback, dst, src); 113 } else { 114 pagefault_disable(); 115 enable_kernel_altivec(); 116 enable_kernel_vsx(); 117 aes_p8_decrypt(src, dst, &ctx->dec_key); 118 pagefault_enable(); 119 } 120} 121 122struct crypto_alg p8_aes_alg = { 123 .cra_name = "aes", 124 .cra_driver_name = "p8_aes", 125 .cra_module = THIS_MODULE, 126 .cra_priority = 1000, 127 .cra_type = NULL, 128 .cra_flags = CRYPTO_ALG_TYPE_CIPHER | CRYPTO_ALG_NEED_FALLBACK, 129 .cra_alignmask = 0, 130 .cra_blocksize = AES_BLOCK_SIZE, 131 .cra_ctxsize = sizeof(struct p8_aes_ctx), 132 .cra_init = p8_aes_init, 133 .cra_exit = p8_aes_exit, 134 .cra_cipher = { 135 .cia_min_keysize = AES_MIN_KEY_SIZE, 136 .cia_max_keysize = AES_MAX_KEY_SIZE, 137 .cia_setkey = p8_aes_setkey, 138 .cia_encrypt = p8_aes_encrypt, 139 .cia_decrypt = p8_aes_decrypt, 140 }, 141}; 142 143