tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 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
91static 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
105static 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
119struct 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