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
22struct p8_aes_ctx {
23	struct crypto_cipher *fallback;
24	struct aes_key enc_key;
25	struct aes_key dec_key;
26};
27
28static 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
51static 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
61static 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
81static 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
98static 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
115struct 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