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 32 struct p8_aes_ctx { 33 struct crypto_cipher *fallback; 34 struct aes_key enc_key; 35 struct aes_key dec_key; 36 }; 37 38 static 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 65 static 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 75 static 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 ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key); 84 ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key); 85 pagefault_enable(); 86 87 ret += crypto_cipher_setkey(ctx->fallback, key, keylen); 88 return ret; 89 } 90 91 static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) 92 { 93 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 94 95 if (in_interrupt()) { 96 crypto_cipher_encrypt_one(ctx->fallback, dst, src); 97 } else { 98 pagefault_disable(); 99 enable_kernel_altivec(); 100 aes_p8_encrypt(src, dst, &ctx->enc_key); 101 pagefault_enable(); 102 } 103 } 104 105 static void p8_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) 106 { 107 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 108 109 if (in_interrupt()) { 110 crypto_cipher_decrypt_one(ctx->fallback, dst, src); 111 } else { 112 pagefault_disable(); 113 enable_kernel_altivec(); 114 aes_p8_decrypt(src, dst, &ctx->dec_key); 115 pagefault_enable(); 116 } 117 } 118 119 struct crypto_alg p8_aes_alg = { 120 .cra_name = "aes", 121 .cra_driver_name = "p8_aes", 122 .cra_module = THIS_MODULE, 123 .cra_priority = 1000, 124 .cra_type = NULL, 125 .cra_flags = CRYPTO_ALG_TYPE_CIPHER | CRYPTO_ALG_NEED_FALLBACK, 126 .cra_alignmask = 0, 127 .cra_blocksize = AES_BLOCK_SIZE, 128 .cra_ctxsize = sizeof(struct p8_aes_ctx), 129 .cra_init = p8_aes_init, 130 .cra_exit = p8_aes_exit, 131 .cra_cipher = { 132 .cia_min_keysize = AES_MIN_KEY_SIZE, 133 .cia_max_keysize = AES_MAX_KEY_SIZE, 134 .cia_setkey = p8_aes_setkey, 135 .cia_encrypt = p8_aes_encrypt, 136 .cia_decrypt = p8_aes_decrypt, 137 }, 138 }; 139 140