1/*
2 * FPU: Wrapper for blkcipher touching fpu
3 *
4 * Copyright (c) Intel Corp.
5 *   Author: Huang Ying <ying.huang@intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the Free
9 * Software Foundation; either version 2 of the License, or (at your option)
10 * any later version.
11 *
12 */
13
14#include <crypto/algapi.h>
15#include <linux/err.h>
16#include <linux/init.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20#include <linux/crypto.h>
21#include <asm/i387.h>
22
23struct crypto_fpu_ctx {
24	struct crypto_blkcipher *child;
25};
26
27static int crypto_fpu_setkey(struct crypto_tfm *parent, const u8 *key,
28			     unsigned int keylen)
29{
30	struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(parent);
31	struct crypto_blkcipher *child = ctx->child;
32	int err;
33
34	crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
35	crypto_blkcipher_set_flags(child, crypto_tfm_get_flags(parent) &
36				   CRYPTO_TFM_REQ_MASK);
37	err = crypto_blkcipher_setkey(child, key, keylen);
38	crypto_tfm_set_flags(parent, crypto_blkcipher_get_flags(child) &
39				     CRYPTO_TFM_RES_MASK);
40	return err;
41}
42
43static int crypto_fpu_encrypt(struct blkcipher_desc *desc_in,
44			      struct scatterlist *dst, struct scatterlist *src,
45			      unsigned int nbytes)
46{
47	int err;
48	struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
49	struct crypto_blkcipher *child = ctx->child;
50	struct blkcipher_desc desc = {
51		.tfm = child,
52		.info = desc_in->info,
53		.flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
54	};
55
56	kernel_fpu_begin();
57	err = crypto_blkcipher_crt(desc.tfm)->encrypt(&desc, dst, src, nbytes);
58	kernel_fpu_end();
59	return err;
60}
61
62static int crypto_fpu_decrypt(struct blkcipher_desc *desc_in,
63			      struct scatterlist *dst, struct scatterlist *src,
64			      unsigned int nbytes)
65{
66	int err;
67	struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
68	struct crypto_blkcipher *child = ctx->child;
69	struct blkcipher_desc desc = {
70		.tfm = child,
71		.info = desc_in->info,
72		.flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
73	};
74
75	kernel_fpu_begin();
76	err = crypto_blkcipher_crt(desc.tfm)->decrypt(&desc, dst, src, nbytes);
77	kernel_fpu_end();
78	return err;
79}
80
81static int crypto_fpu_init_tfm(struct crypto_tfm *tfm)
82{
83	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
84	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
85	struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
86	struct crypto_blkcipher *cipher;
87
88	cipher = crypto_spawn_blkcipher(spawn);
89	if (IS_ERR(cipher))
90		return PTR_ERR(cipher);
91
92	ctx->child = cipher;
93	return 0;
94}
95
96static void crypto_fpu_exit_tfm(struct crypto_tfm *tfm)
97{
98	struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
99	crypto_free_blkcipher(ctx->child);
100}
101
102static struct crypto_instance *crypto_fpu_alloc(struct rtattr **tb)
103{
104	struct crypto_instance *inst;
105	struct crypto_alg *alg;
106	int err;
107
108	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
109	if (err)
110		return ERR_PTR(err);
111
112	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
113				  CRYPTO_ALG_TYPE_MASK);
114	if (IS_ERR(alg))
115		return ERR_CAST(alg);
116
117	inst = crypto_alloc_instance("fpu", alg);
118	if (IS_ERR(inst))
119		goto out_put_alg;
120
121	inst->alg.cra_flags = alg->cra_flags;
122	inst->alg.cra_priority = alg->cra_priority;
123	inst->alg.cra_blocksize = alg->cra_blocksize;
124	inst->alg.cra_alignmask = alg->cra_alignmask;
125	inst->alg.cra_type = alg->cra_type;
126	inst->alg.cra_blkcipher.ivsize = alg->cra_blkcipher.ivsize;
127	inst->alg.cra_blkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
128	inst->alg.cra_blkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
129	inst->alg.cra_ctxsize = sizeof(struct crypto_fpu_ctx);
130	inst->alg.cra_init = crypto_fpu_init_tfm;
131	inst->alg.cra_exit = crypto_fpu_exit_tfm;
132	inst->alg.cra_blkcipher.setkey = crypto_fpu_setkey;
133	inst->alg.cra_blkcipher.encrypt = crypto_fpu_encrypt;
134	inst->alg.cra_blkcipher.decrypt = crypto_fpu_decrypt;
135
136out_put_alg:
137	crypto_mod_put(alg);
138	return inst;
139}
140
141static void crypto_fpu_free(struct crypto_instance *inst)
142{
143	crypto_drop_spawn(crypto_instance_ctx(inst));
144	kfree(inst);
145}
146
147static struct crypto_template crypto_fpu_tmpl = {
148	.name = "fpu",
149	.alloc = crypto_fpu_alloc,
150	.free = crypto_fpu_free,
151	.module = THIS_MODULE,
152};
153
154int __init crypto_fpu_init(void)
155{
156	return crypto_register_template(&crypto_fpu_tmpl);
157}
158
159void __exit crypto_fpu_exit(void)
160{
161	crypto_unregister_template(&crypto_fpu_tmpl);
162}
163
164MODULE_ALIAS_CRYPTO("fpu");
165