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-rw-r--r--drivers/crypto/vmx/aes_cbc.c184
1 files changed, 184 insertions, 0 deletions
diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
new file mode 100644
index 000000000000..1a559b7dddb5
--- /dev/null
+++ b/drivers/crypto/vmx/aes_cbc.c
@@ -0,0 +1,184 @@
1/**
2 * AES CBC 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#include <crypto/scatterwalk.h>
30
31#include "aesp8-ppc.h"
32
33struct p8_aes_cbc_ctx {
34 struct crypto_blkcipher *fallback;
35 struct aes_key enc_key;
36 struct aes_key dec_key;
37};
38
39static int p8_aes_cbc_init(struct crypto_tfm *tfm)
40{
41 const char *alg;
42 struct crypto_blkcipher *fallback;
43 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
44
45 if (!(alg = crypto_tfm_alg_name(tfm))) {
46 printk(KERN_ERR "Failed to get algorithm name.\n");
47 return -ENOENT;
48 }
49
50 fallback = crypto_alloc_blkcipher(alg, 0 ,CRYPTO_ALG_NEED_FALLBACK);
51 if (IS_ERR(fallback)) {
52 printk(KERN_ERR "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_blkcipher_set_flags(fallback,
60 crypto_blkcipher_get_flags((struct crypto_blkcipher *) tfm));
61 ctx->fallback = fallback;
62
63 return 0;
64}
65
66static void p8_aes_cbc_exit(struct crypto_tfm *tfm)
67{
68 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
69
70 if (ctx->fallback) {
71 crypto_free_blkcipher(ctx->fallback);
72 ctx->fallback = NULL;
73 }
74}
75
76static int p8_aes_cbc_setkey(struct crypto_tfm *tfm, const u8 *key,
77 unsigned int keylen)
78{
79 int ret;
80 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
81
82 pagefault_disable();
83 enable_kernel_altivec();
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_blkcipher_setkey(ctx->fallback, key, keylen);
89 return ret;
90}
91
92static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
93 struct scatterlist *dst, struct scatterlist *src,
94 unsigned int nbytes)
95{
96 int ret;
97 struct blkcipher_walk walk;
98 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(
99 crypto_blkcipher_tfm(desc->tfm));
100 struct blkcipher_desc fallback_desc = {
101 .tfm = ctx->fallback,
102 .info = desc->info,
103 .flags = desc->flags
104 };
105
106 if (in_interrupt()) {
107 ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src, nbytes);
108 } else {
109 pagefault_disable();
110 enable_kernel_altivec();
111
112 blkcipher_walk_init(&walk, dst, src, nbytes);
113 ret = blkcipher_walk_virt(desc, &walk);
114 while ((nbytes = walk.nbytes)) {
115 aes_p8_cbc_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
116 nbytes & AES_BLOCK_MASK, &ctx->enc_key, walk.iv, 1);
117 nbytes &= AES_BLOCK_SIZE - 1;
118 ret = blkcipher_walk_done(desc, &walk, nbytes);
119 }
120
121 pagefault_enable();
122 }
123
124 return ret;
125}
126
127static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
128 struct scatterlist *dst, struct scatterlist *src,
129 unsigned int nbytes)
130{
131 int ret;
132 struct blkcipher_walk walk;
133 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(
134 crypto_blkcipher_tfm(desc->tfm));
135 struct blkcipher_desc fallback_desc = {
136 .tfm = ctx->fallback,
137 .info = desc->info,
138 .flags = desc->flags
139 };
140
141 if (in_interrupt()) {
142 ret = crypto_blkcipher_decrypt(&fallback_desc, dst, src, nbytes);
143 } else {
144 pagefault_disable();
145 enable_kernel_altivec();
146
147 blkcipher_walk_init(&walk, dst, src, nbytes);
148 ret = blkcipher_walk_virt(desc, &walk);
149 while ((nbytes = walk.nbytes)) {
150 aes_p8_cbc_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
151 nbytes & AES_BLOCK_MASK, &ctx->dec_key, walk.iv, 0);
152 nbytes &= AES_BLOCK_SIZE - 1;
153 ret = blkcipher_walk_done(desc, &walk, nbytes);
154 }
155
156 pagefault_enable();
157 }
158
159 return ret;
160}
161
162
163struct crypto_alg p8_aes_cbc_alg = {
164 .cra_name = "cbc(aes)",
165 .cra_driver_name = "p8_aes_cbc",
166 .cra_module = THIS_MODULE,
167 .cra_priority = 1000,
168 .cra_type = &crypto_blkcipher_type,
169 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
170 .cra_alignmask = 0,
171 .cra_blocksize = AES_BLOCK_SIZE,
172 .cra_ctxsize = sizeof(struct p8_aes_cbc_ctx),
173 .cra_init = p8_aes_cbc_init,
174 .cra_exit = p8_aes_cbc_exit,
175 .cra_blkcipher = {
176 .ivsize = 0,
177 .min_keysize = AES_MIN_KEY_SIZE,
178 .max_keysize = AES_MAX_KEY_SIZE,
179 .setkey = p8_aes_cbc_setkey,
180 .encrypt = p8_aes_cbc_encrypt,
181 .decrypt = p8_aes_cbc_decrypt,
182 },
183};
184