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 <asm/i387.h>
 21
 22struct crypto_fpu_ctx {
 23	struct crypto_blkcipher *child;
 24};
 25
 26static int crypto_fpu_setkey(struct crypto_tfm *parent, const u8 *key,
 27			     unsigned int keylen)
 28{
 29	struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(parent);
 30	struct crypto_blkcipher *child = ctx->child;
 31	int err;
 32
 33	crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 34	crypto_blkcipher_set_flags(child, crypto_tfm_get_flags(parent) &
 35				   CRYPTO_TFM_REQ_MASK);
 36	err = crypto_blkcipher_setkey(child, key, keylen);
 37	crypto_tfm_set_flags(parent, crypto_blkcipher_get_flags(child) &
 38				     CRYPTO_TFM_RES_MASK);
 39	return err;
 40}
 41
 42static int crypto_fpu_encrypt(struct blkcipher_desc *desc_in,
 43			      struct scatterlist *dst, struct scatterlist *src,
 44			      unsigned int nbytes)
 45{
 46	int err;
 47	struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
 48	struct crypto_blkcipher *child = ctx->child;
 49	struct blkcipher_desc desc = {
 50		.tfm = child,
 51		.info = desc_in->info,
 52		.flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
 53	};
 54
 55	kernel_fpu_begin();
 56	err = crypto_blkcipher_crt(desc.tfm)->encrypt(&desc, dst, src, nbytes);
 57	kernel_fpu_end();
 58	return err;
 59}
 60
 61static int crypto_fpu_decrypt(struct blkcipher_desc *desc_in,
 62			      struct scatterlist *dst, struct scatterlist *src,
 63			      unsigned int nbytes)
 64{
 65	int err;
 66	struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
 67	struct crypto_blkcipher *child = ctx->child;
 68	struct blkcipher_desc desc = {
 69		.tfm = child,
 70		.info = desc_in->info,
 71		.flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
 72	};
 73
 74	kernel_fpu_begin();
 75	err = crypto_blkcipher_crt(desc.tfm)->decrypt(&desc, dst, src, nbytes);
 76	kernel_fpu_end();
 77	return err;
 78}
 79
 80static int crypto_fpu_init_tfm(struct crypto_tfm *tfm)
 81{
 82	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
 83	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
 84	struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
 85	struct crypto_blkcipher *cipher;
 86
 87	cipher = crypto_spawn_blkcipher(spawn);
 88	if (IS_ERR(cipher))
 89		return PTR_ERR(cipher);
 90
 91	ctx->child = cipher;
 92	return 0;
 93}
 94
 95static void crypto_fpu_exit_tfm(struct crypto_tfm *tfm)
 96{
 97	struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
 98	crypto_free_blkcipher(ctx->child);
 99}
100
101static struct crypto_instance *crypto_fpu_alloc(struct rtattr **tb)
102{
103	struct crypto_instance *inst;
104	struct crypto_alg *alg;
105	int err;
106
107	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
108	if (err)
109		return ERR_PTR(err);
110
111	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
112				  CRYPTO_ALG_TYPE_MASK);
113	if (IS_ERR(alg))
114		return ERR_CAST(alg);
115
116	inst = crypto_alloc_instance("fpu", alg);
117	if (IS_ERR(inst))
118		goto out_put_alg;
119
120	inst->alg.cra_flags = alg->cra_flags;
121	inst->alg.cra_priority = alg->cra_priority;
122	inst->alg.cra_blocksize = alg->cra_blocksize;
123	inst->alg.cra_alignmask = alg->cra_alignmask;
124	inst->alg.cra_type = alg->cra_type;
125	inst->alg.cra_blkcipher.ivsize = alg->cra_blkcipher.ivsize;
126	inst->alg.cra_blkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
127	inst->alg.cra_blkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
128	inst->alg.cra_ctxsize = sizeof(struct crypto_fpu_ctx);
129	inst->alg.cra_init = crypto_fpu_init_tfm;
130	inst->alg.cra_exit = crypto_fpu_exit_tfm;
131	inst->alg.cra_blkcipher.setkey = crypto_fpu_setkey;
132	inst->alg.cra_blkcipher.encrypt = crypto_fpu_encrypt;
133	inst->alg.cra_blkcipher.decrypt = crypto_fpu_decrypt;
134
135out_put_alg:
136	crypto_mod_put(alg);
137	return inst;
138}
139
140static void crypto_fpu_free(struct crypto_instance *inst)
141{
142	crypto_drop_spawn(crypto_instance_ctx(inst));
143	kfree(inst);
144}
145
146static struct crypto_template crypto_fpu_tmpl = {
147	.name = "fpu",
148	.alloc = crypto_fpu_alloc,
149	.free = crypto_fpu_free,
150	.module = THIS_MODULE,
151};
152
153int __init crypto_fpu_init(void)
154{
155	return crypto_register_template(&crypto_fpu_tmpl);
156}
157
158void __exit crypto_fpu_exit(void)
159{
160	crypto_unregister_template(&crypto_fpu_tmpl);
161}