1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AES routines supporting VMX instructions on the Power 8
4 *
5 * Copyright (C) 2015 International Business Machines Inc.
6 *
7 * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
8 */
9
10 #include <linux/types.h>
11 #include <linux/err.h>
12 #include <linux/crypto.h>
13 #include <linux/delay.h>
14 #include <asm/simd.h>
15 #include <asm/switch_to.h>
16 #include <crypto/aes.h>
17 #include <crypto/internal/cipher.h>
18 #include <crypto/internal/simd.h>
19
20 #include "aesp8-ppc.h"
21
22 struct p8_aes_ctx {
23 struct crypto_cipher *fallback;
24 struct aes_key enc_key;
25 struct aes_key dec_key;
26 };
27
28 static int p8_aes_init(struct crypto_tfm *tfm)
29 {
30 const char *alg = crypto_tfm_alg_name(tfm);
31 struct crypto_cipher *fallback;
32 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
33
34 fallback = crypto_alloc_cipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
35 if (IS_ERR(fallback)) {
36 printk(KERN_ERR
37 "Failed to allocate transformation for '%s': %ld\n",
38 alg, PTR_ERR(fallback));
39 return PTR_ERR(fallback);
40 }
41
42 crypto_cipher_set_flags(fallback,
43 crypto_cipher_get_flags((struct
44 crypto_cipher *)
45 tfm));
46 ctx->fallback = fallback;
47
48 return 0;
49 }
50
51 static void p8_aes_exit(struct crypto_tfm *tfm)
52 {
53 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
54
55 if (ctx->fallback) {
56 crypto_free_cipher(ctx->fallback);
57 ctx->fallback = NULL;
58 }
59 }
60
61 static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key,
62 unsigned int keylen)
63 {
64 int ret;
65 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
66
67 preempt_disable();
68 pagefault_disable();
69 enable_kernel_vsx();
70 ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
71 ret |= aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
72 disable_kernel_vsx();
73 pagefault_enable();
74 preempt_enable();
75
76 ret |= crypto_cipher_setkey(ctx->fallback, key, keylen);
77
78 return ret ? -EINVAL : 0;
79 }
80
81 static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
82 {
83 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
84
85 if (!crypto_simd_usable()) {
86 crypto_cipher_encrypt_one(ctx->fallback, dst, src);
87 } else {
88 preempt_disable();
89 pagefault_disable();
90 enable_kernel_vsx();
91 aes_p8_encrypt(src, dst, &ctx->enc_key);
92 disable_kernel_vsx();
93 pagefault_enable();
94 preempt_enable();
95 }
96 }
97
98 static void p8_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
99 {
100 struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
101
102 if (!crypto_simd_usable()) {
103 crypto_cipher_decrypt_one(ctx->fallback, dst, src);
104 } else {
105 preempt_disable();
106 pagefault_disable();
107 enable_kernel_vsx();
108 aes_p8_decrypt(src, dst, &ctx->dec_key);
109 disable_kernel_vsx();
110 pagefault_enable();
111 preempt_enable();
112 }
113 }
114
115 struct crypto_alg p8_aes_alg = {
116 .cra_name = "aes",
117 .cra_driver_name = "p8_aes",
118 .cra_module = THIS_MODULE,
119 .cra_priority = 1000,
120 .cra_type = NULL,
121 .cra_flags = CRYPTO_ALG_TYPE_CIPHER | CRYPTO_ALG_NEED_FALLBACK,
122 .cra_alignmask = 0,
123 .cra_blocksize = AES_BLOCK_SIZE,
124 .cra_ctxsize = sizeof(struct p8_aes_ctx),
125 .cra_init = p8_aes_init,
126 .cra_exit = p8_aes_exit,
127 .cra_cipher = {
128 .cia_min_keysize = AES_MIN_KEY_SIZE,
129 .cia_max_keysize = AES_MAX_KEY_SIZE,
130 .cia_setkey = p8_aes_setkey,
131 .cia_encrypt = p8_aes_encrypt,
132 .cia_decrypt = p8_aes_decrypt,
133 },
134 };
135
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