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
p8_aes_init(struct crypto_tfm * tfm)38 static int p8_aes_init(struct crypto_tfm *tfm)
39 {
40 const char *alg = crypto_tfm_alg_name(tfm);
41 struct crypto_cipher *fallback;
42 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
43
44 fallback = crypto_alloc_cipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
45 if (IS_ERR(fallback)) {
46 printk(KERN_ERR
47 "Failed to allocate transformation for '%s': %ld\n",
48 alg, PTR_ERR(fallback));
49 return PTR_ERR(fallback);
50 }
51
52 crypto_cipher_set_flags(fallback,
53 crypto_cipher_get_flags((struct
54 crypto_cipher *)
55 tfm));
56 ctx->fallback = fallback;
57
58 return 0;
59 }
60
p8_aes_exit(struct crypto_tfm * tfm)61 static void p8_aes_exit(struct crypto_tfm *tfm)
62 {
63 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
64
65 if (ctx->fallback) {
66 crypto_free_cipher(ctx->fallback);
67 ctx->fallback = NULL;
68 }
69 }
70
p8_aes_setkey(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)71 static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key,
72 unsigned int keylen)
73 {
74 int ret;
75 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
76
77 preempt_disable();
78 pagefault_disable();
79 enable_kernel_vsx();
80 ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
81 ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
82 disable_kernel_vsx();
83 pagefault_enable();
84 preempt_enable();
85
86 ret += crypto_cipher_setkey(ctx->fallback, key, keylen);
87 return ret;
88 }
89
p8_aes_encrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)90 static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
91 {
92 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
93
94 if (in_interrupt()) {
95 crypto_cipher_encrypt_one(ctx->fallback, dst, src);
96 } else {
97 preempt_disable();
98 pagefault_disable();
99 enable_kernel_vsx();
100 aes_p8_encrypt(src, dst, &ctx->enc_key);
101 disable_kernel_vsx();
102 pagefault_enable();
103 preempt_enable();
104 }
105 }
106
p8_aes_decrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)107 static 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 preempt_disable();
115 pagefault_disable();
116 enable_kernel_vsx();
117 aes_p8_decrypt(src, dst, &ctx->dec_key);
118 disable_kernel_vsx();
119 pagefault_enable();
120 preempt_enable();
121 }
122 }
123
124 struct crypto_alg p8_aes_alg = {
125 .cra_name = "aes",
126 .cra_driver_name = "p8_aes",
127 .cra_module = THIS_MODULE,
128 .cra_priority = 1000,
129 .cra_type = NULL,
130 .cra_flags = CRYPTO_ALG_TYPE_CIPHER | CRYPTO_ALG_NEED_FALLBACK,
131 .cra_alignmask = 0,
132 .cra_blocksize = AES_BLOCK_SIZE,
133 .cra_ctxsize = sizeof(struct p8_aes_ctx),
134 .cra_init = p8_aes_init,
135 .cra_exit = p8_aes_exit,
136 .cra_cipher = {
137 .cia_min_keysize = AES_MIN_KEY_SIZE,
138 .cia_max_keysize = AES_MAX_KEY_SIZE,
139 .cia_setkey = p8_aes_setkey,
140 .cia_encrypt = p8_aes_encrypt,
141 .cia_decrypt = p8_aes_decrypt,
142 },
143 };
144
