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 
p8_aes_init(struct crypto_tfm * tfm)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 
p8_aes_exit(struct crypto_tfm * tfm)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 
p8_aes_setkey(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)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 
p8_aes_encrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)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 
p8_aes_decrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)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