[linux-2.6-block.git] / drivers / crypto / vmx / aes_cbc.c

/**
 * AES CBC routines supporting VMX instructions on the Power 8
 *
 * Copyright (C) 2015 International Business Machines Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 only.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
 */

#include <linux/types.h>
#include <linux/err.h>
#include <linux/crypto.h>
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <asm/switch_to.h>
#include <crypto/aes.h>
#include <crypto/scatterwalk.h>
#include <crypto/skcipher.h>

#include "aesp8-ppc.h"

struct p8_aes_cbc_ctx {
	struct crypto_skcipher *fallback;
	struct aes_key enc_key;
	struct aes_key dec_key;
};

static int p8_aes_cbc_init(struct crypto_tfm *tfm)
{
	const char *alg = crypto_tfm_alg_name(tfm);
	struct crypto_skcipher *fallback;
	struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);

	fallback = crypto_alloc_skcipher(alg, 0,
			CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);

	if (IS_ERR(fallback)) {
		printk(KERN_ERR
		       "Failed to allocate transformation for '%s': %ld\n",
		       alg, PTR_ERR(fallback));
		return PTR_ERR(fallback);
	}

	crypto_skcipher_set_flags(
		fallback,
		crypto_skcipher_get_flags((struct crypto_skcipher *)tfm));
	ctx->fallback = fallback;

	return 0;
}

static void p8_aes_cbc_exit(struct crypto_tfm *tfm)
{
	struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);

	if (ctx->fallback) {
		crypto_free_skcipher(ctx->fallback);
		ctx->fallback = NULL;
	}
}

static int p8_aes_cbc_setkey(struct crypto_tfm *tfm, const u8 *key,
			     unsigned int keylen)
{
	int ret;
	struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);

	preempt_disable();
	pagefault_disable();
	enable_kernel_vsx();
	ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
	ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
	disable_kernel_vsx();
	pagefault_enable();
	preempt_enable();

	ret += crypto_skcipher_setkey(ctx->fallback, key, keylen);
	return ret;
}

static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
			      struct scatterlist *dst,
			      struct scatterlist *src, unsigned int nbytes)
{
	int ret;
	struct blkcipher_walk walk;
	struct p8_aes_cbc_ctx *ctx =
		crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));

	if (in_interrupt()) {
		SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback);
		skcipher_request_set_tfm(req, ctx->fallback);
		skcipher_request_set_callback(req, desc->flags, NULL, NULL);
		skcipher_request_set_crypt(req, src, dst, nbytes, desc->info);
		ret = crypto_skcipher_encrypt(req);
		skcipher_request_zero(req);
	} else {
		blkcipher_walk_init(&walk, dst, src, nbytes);
		ret = blkcipher_walk_virt(desc, &walk);
		while ((nbytes = walk.nbytes)) {
			preempt_disable();
			pagefault_disable();
			enable_kernel_vsx();
			aes_p8_cbc_encrypt(walk.src.virt.addr,
					   walk.dst.virt.addr,
					   nbytes & AES_BLOCK_MASK,
					   &ctx->enc_key, walk.iv, 1);
			disable_kernel_vsx();
			pagefault_enable();
			preempt_enable();

			nbytes &= AES_BLOCK_SIZE - 1;
			ret = blkcipher_walk_done(desc, &walk, nbytes);
		}
	}

	return ret;
}

static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
			      struct scatterlist *dst,
			      struct scatterlist *src, unsigned int nbytes)
{
	int ret;
	struct blkcipher_walk walk;
	struct p8_aes_cbc_ctx *ctx =
		crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));

	if (in_interrupt()) {
		SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback);
		skcipher_request_set_tfm(req, ctx->fallback);
		skcipher_request_set_callback(req, desc->flags, NULL, NULL);
		skcipher_request_set_crypt(req, src, dst, nbytes, desc->info);
		ret = crypto_skcipher_decrypt(req);
		skcipher_request_zero(req);
	} else {
		blkcipher_walk_init(&walk, dst, src, nbytes);
		ret = blkcipher_walk_virt(desc, &walk);
		while ((nbytes = walk.nbytes)) {
			preempt_disable();
			pagefault_disable();
			enable_kernel_vsx();
			aes_p8_cbc_encrypt(walk.src.virt.addr,
					   walk.dst.virt.addr,
					   nbytes & AES_BLOCK_MASK,
					   &ctx->dec_key, walk.iv, 0);
			disable_kernel_vsx();
			pagefault_enable();
			preempt_enable();

			nbytes &= AES_BLOCK_SIZE - 1;
			ret = blkcipher_walk_done(desc, &walk, nbytes);
		}
	}

	return ret;
}


struct crypto_alg p8_aes_cbc_alg = {
	.cra_name = "cbc(aes)",
	.cra_driver_name = "p8_aes_cbc",
	.cra_module = THIS_MODULE,
	.cra_priority = 2000,
	.cra_type = &crypto_blkcipher_type,
	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
	.cra_alignmask = 0,
	.cra_blocksize = AES_BLOCK_SIZE,
	.cra_ctxsize = sizeof(struct p8_aes_cbc_ctx),
	.cra_init = p8_aes_cbc_init,
	.cra_exit = p8_aes_cbc_exit,
	.cra_blkcipher = {
			  .ivsize = AES_BLOCK_SIZE,
			  .min_keysize = AES_MIN_KEY_SIZE,
			  .max_keysize = AES_MAX_KEY_SIZE,
			  .setkey = p8_aes_cbc_setkey,
			  .encrypt = p8_aes_cbc_encrypt,
			  .decrypt = p8_aes_cbc_decrypt,
	},
};
Commit	Line	Data
8c755ace MC	1	/**
	2	* AES CBC routines supporting VMX instructions on the Power 8
	3	*
	4	* Copyright (C) 2015 International Business Machines Inc.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; version 2 only.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	18	*
	19	* Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
	20	*/
	21
	22	#include <linux/types.h>
	23	#include <linux/err.h>
	24	#include <linux/crypto.h>
	25	#include <linux/delay.h>
	26	#include <linux/hardirq.h>
	27	#include <asm/switch_to.h>
	28	#include <crypto/aes.h>
	29	#include <crypto/scatterwalk.h>
c96d0a1c	30	#include <crypto/skcipher.h>
8c755ace MC	31
	32	#include "aesp8-ppc.h"
	33
	34	struct p8_aes_cbc_ctx {
c96d0a1c	35	struct crypto_skcipher *fallback;
4beb1060 HX	36	struct aes_key enc_key;
4beb1060 HX	37	struct aes_key dec_key;
8c755ace MC	38	};
	39
	40	static int p8_aes_cbc_init(struct crypto_tfm *tfm)
	41	{
78557e77	42	const char *alg = crypto_tfm_alg_name(tfm);
c96d0a1c	43	struct crypto_skcipher *fallback;
4beb1060 HX	44	struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
4beb1060 HX	45
c96d0a1c PFS	46	fallback = crypto_alloc_skcipher(alg, 0,
	47	CRYPTO_ALG_ASYNC \| CRYPTO_ALG_NEED_FALLBACK);
	48
4beb1060 HX	49	if (IS_ERR(fallback)) {
	50	printk(KERN_ERR
	51	"Failed to allocate transformation for '%s': %ld\n",
	52	alg, PTR_ERR(fallback));
	53	return PTR_ERR(fallback);
	54	}
4beb1060	55
c96d0a1c	56	crypto_skcipher_set_flags(
4beb1060	57	fallback,
c96d0a1c	58	crypto_skcipher_get_flags((struct crypto_skcipher *)tfm));
4beb1060 HX	59	ctx->fallback = fallback;
	60
	61	return 0;
8c755ace MC	62	}
	63
	64	static void p8_aes_cbc_exit(struct crypto_tfm *tfm)
	65	{
4beb1060	66	struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
8c755ace	67
4beb1060	68	if (ctx->fallback) {
c96d0a1c	69	crypto_free_skcipher(ctx->fallback);
4beb1060 HX	70	ctx->fallback = NULL;
4beb1060 HX	71	}
8c755ace MC	72	}
	73
	74	static int p8_aes_cbc_setkey(struct crypto_tfm tfm, const u8 key,
4beb1060	75	unsigned int keylen)
8c755ace	76	{
4beb1060 HX	77	int ret;
4beb1060 HX	78	struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
8c755ace	79
44d21c3f	80	preempt_disable();
4beb1060	81	pagefault_disable();
2d6f0600	82	enable_kernel_vsx();
4beb1060 HX	83	ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
4beb1060 HX	84	ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
dc4fbba1	85	disable_kernel_vsx();
4beb1060	86	pagefault_enable();
44d21c3f	87	preempt_enable();
8c755ace	88
c96d0a1c	89	ret += crypto_skcipher_setkey(ctx->fallback, key, keylen);
4beb1060	90	return ret;
8c755ace MC	91	}
	92
	93	static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
4beb1060 HX	94	struct scatterlist *dst,
4beb1060 HX	95	struct scatterlist *src, unsigned int nbytes)
8c755ace	96	{
4beb1060 HX	97	int ret;
	98	struct blkcipher_walk walk;
	99	struct p8_aes_cbc_ctx *ctx =
	100	crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
4beb1060 HX	101
4beb1060 HX	102	if (in_interrupt()) {
c96d0a1c PFS	103	SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback);
	104	skcipher_request_set_tfm(req, ctx->fallback);
	105	skcipher_request_set_callback(req, desc->flags, NULL, NULL);
	106	skcipher_request_set_crypt(req, src, dst, nbytes, desc->info);
	107	ret = crypto_skcipher_encrypt(req);
	108	skcipher_request_zero(req);
4beb1060	109	} else {
4beb1060 HX	110	blkcipher_walk_init(&walk, dst, src, nbytes);
	111	ret = blkcipher_walk_virt(desc, &walk);
	112	while ((nbytes = walk.nbytes)) {
0522236d OM	113	preempt_disable();
	114	pagefault_disable();
	115	enable_kernel_vsx();
4beb1060 HX	116	aes_p8_cbc_encrypt(walk.src.virt.addr,
	117	walk.dst.virt.addr,
	118	nbytes & AES_BLOCK_MASK,
	119	&ctx->enc_key, walk.iv, 1);
0522236d OM	120	disable_kernel_vsx();
	121	pagefault_enable();
	122	preempt_enable();
	123
8c755ace MC	124	nbytes &= AES_BLOCK_SIZE - 1;
8c755ace MC	125	ret = blkcipher_walk_done(desc, &walk, nbytes);
4beb1060	126	}
4beb1060	127	}
8c755ace	128
4beb1060	129	return ret;
8c755ace MC	130	}
	131
	132	static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
4beb1060 HX	133	struct scatterlist *dst,
4beb1060 HX	134	struct scatterlist *src, unsigned int nbytes)
8c755ace	135	{
4beb1060 HX	136	int ret;
	137	struct blkcipher_walk walk;
	138	struct p8_aes_cbc_ctx *ctx =
	139	crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
4beb1060 HX	140
4beb1060 HX	141	if (in_interrupt()) {
c96d0a1c PFS	142	SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback);
	143	skcipher_request_set_tfm(req, ctx->fallback);
	144	skcipher_request_set_callback(req, desc->flags, NULL, NULL);
	145	skcipher_request_set_crypt(req, src, dst, nbytes, desc->info);
	146	ret = crypto_skcipher_decrypt(req);
	147	skcipher_request_zero(req);
4beb1060	148	} else {
4beb1060 HX	149	blkcipher_walk_init(&walk, dst, src, nbytes);
	150	ret = blkcipher_walk_virt(desc, &walk);
	151	while ((nbytes = walk.nbytes)) {
0522236d OM	152	preempt_disable();
	153	pagefault_disable();
	154	enable_kernel_vsx();
4beb1060 HX	155	aes_p8_cbc_encrypt(walk.src.virt.addr,
	156	walk.dst.virt.addr,
	157	nbytes & AES_BLOCK_MASK,
	158	&ctx->dec_key, walk.iv, 0);
0522236d OM	159	disable_kernel_vsx();
	160	pagefault_enable();
	161	preempt_enable();
	162
8c755ace MC	163	nbytes &= AES_BLOCK_SIZE - 1;
	164	ret = blkcipher_walk_done(desc, &walk, nbytes);
	165	}
4beb1060	166	}
8c755ace	167
4beb1060	168	return ret;
8c755ace MC	169	}
	170
	171
	172	struct crypto_alg p8_aes_cbc_alg = {
4beb1060 HX	173	.cra_name = "cbc(aes)",
	174	.cra_driver_name = "p8_aes_cbc",
	175	.cra_module = THIS_MODULE,
12d3f49e	176	.cra_priority = 2000,
4beb1060 HX	177	.cra_type = &crypto_blkcipher_type,
	178	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER \| CRYPTO_ALG_NEED_FALLBACK,
	179	.cra_alignmask = 0,
	180	.cra_blocksize = AES_BLOCK_SIZE,
	181	.cra_ctxsize = sizeof(struct p8_aes_cbc_ctx),
	182	.cra_init = p8_aes_cbc_init,
	183	.cra_exit = p8_aes_cbc_exit,
	184	.cra_blkcipher = {
0d3d054b	185	.ivsize = AES_BLOCK_SIZE,
4beb1060 HX	186	.min_keysize = AES_MIN_KEY_SIZE,
	187	.max_keysize = AES_MAX_KEY_SIZE,
	188	.setkey = p8_aes_cbc_setkey,
	189	.encrypt = p8_aes_cbc_encrypt,
	190	.decrypt = p8_aes_cbc_decrypt,
	191	},
8c755ace	192	};