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 52 "Failed to allocate transformation for '%s': %ld\n", 53 alg, PTR_ERR(fallback)); 54 return PTR_ERR(fallback); 55 } 56 printk(KERN_INFO "Using '%s' as fallback implementation.\n", 57 crypto_tfm_alg_driver_name((struct crypto_tfm *) fallback)); 58 59 crypto_cipher_set_flags(fallback, 60 crypto_cipher_get_flags((struct 61 crypto_cipher *) 62 tfm)); 63 ctx->fallback = fallback; 64 65 return 0; 66 } 67 68 static void p8_aes_exit(struct crypto_tfm *tfm) 69 { 70 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 71 72 if (ctx->fallback) { 73 crypto_free_cipher(ctx->fallback); 74 ctx->fallback = NULL; 75 } 76 } 77 78 static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key, 79 unsigned int keylen) 80 { 81 int ret; 82 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 83 84 preempt_disable(); 85 pagefault_disable(); 86 enable_kernel_altivec(); 87 enable_kernel_vsx(); 88 ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key); 89 ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key); 90 pagefault_enable(); 91 preempt_enable(); 92 93 ret += crypto_cipher_setkey(ctx->fallback, key, keylen); 94 return ret; 95 } 96 97 static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) 98 { 99 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 100 101 if (in_interrupt()) { 102 crypto_cipher_encrypt_one(ctx->fallback, dst, src); 103 } else { 104 preempt_disable(); 105 pagefault_disable(); 106 enable_kernel_altivec(); 107 enable_kernel_vsx(); 108 aes_p8_encrypt(src, dst, &ctx->enc_key); 109 pagefault_enable(); 110 preempt_enable(); 111 } 112 } 113 114 static void p8_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) 115 { 116 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm); 117 118 if (in_interrupt()) { 119 crypto_cipher_decrypt_one(ctx->fallback, dst, src); 120 } else { 121 preempt_disable(); 122 pagefault_disable(); 123 enable_kernel_altivec(); 124 enable_kernel_vsx(); 125 aes_p8_decrypt(src, dst, &ctx->dec_key); 126 pagefault_enable(); 127 preempt_enable(); 128 } 129 } 130 131 struct crypto_alg p8_aes_alg = { 132 .cra_name = "aes", 133 .cra_driver_name = "p8_aes", 134 .cra_module = THIS_MODULE, 135 .cra_priority = 1000, 136 .cra_type = NULL, 137 .cra_flags = CRYPTO_ALG_TYPE_CIPHER | CRYPTO_ALG_NEED_FALLBACK, 138 .cra_alignmask = 0, 139 .cra_blocksize = AES_BLOCK_SIZE, 140 .cra_ctxsize = sizeof(struct p8_aes_ctx), 141 .cra_init = p8_aes_init, 142 .cra_exit = p8_aes_exit, 143 .cra_cipher = { 144 .cia_min_keysize = AES_MIN_KEY_SIZE, 145 .cia_max_keysize = AES_MAX_KEY_SIZE, 146 .cia_setkey = p8_aes_setkey, 147 .cia_encrypt = p8_aes_encrypt, 148 .cia_decrypt = p8_aes_decrypt, 149 }, 150 }; 151