[mirror_ubuntu-focal-kernel.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 "aesp8-ppc.h"

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

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

	if (!(alg = crypto_tfm_alg_name(tfm))) {
		printk(KERN_ERR "Failed to get algorithm name.\n");
		return -ENOENT;
	}

	fallback =
	    crypto_alloc_blkcipher(alg, 0, 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);
	}
	printk(KERN_INFO "Using '%s' as fallback implementation.\n",
	       crypto_tfm_alg_driver_name((struct crypto_tfm *) fallback));

	crypto_blkcipher_set_flags(
		fallback,
		crypto_blkcipher_get_flags((struct crypto_blkcipher *)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_blkcipher(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_altivec();
	ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
	ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
	pagefault_enable();
	preempt_enable();

	ret += crypto_blkcipher_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));
	struct blkcipher_desc fallback_desc = {
		.tfm = ctx->fallback,
		.info = desc->info,
		.flags = desc->flags
	};

	if (in_interrupt()) {
		ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src,
					       nbytes);
	} else {
		preempt_disable();
		pagefault_disable();
		enable_kernel_altivec();

		blkcipher_walk_init(&walk, dst, src, nbytes);
		ret = blkcipher_walk_virt(desc, &walk);
		while ((nbytes = walk.nbytes)) {
			aes_p8_cbc_encrypt(walk.src.virt.addr,
					   walk.dst.virt.addr,
					   nbytes & AES_BLOCK_MASK,
					   &ctx->enc_key, walk.iv, 1);
			nbytes &= AES_BLOCK_SIZE - 1;
			ret = blkcipher_walk_done(desc, &walk, nbytes);
		}

		pagefault_enable();
		preempt_enable();
	}

	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));
	struct blkcipher_desc fallback_desc = {
		.tfm = ctx->fallback,
		.info = desc->info,
		.flags = desc->flags
	};

	if (in_interrupt()) {
		ret = crypto_blkcipher_decrypt(&fallback_desc, dst, src,
					       nbytes);
	} else {
		preempt_disable();
		pagefault_disable();
		enable_kernel_altivec();

		blkcipher_walk_init(&walk, dst, src, nbytes);
		ret = blkcipher_walk_virt(desc, &walk);
		while ((nbytes = walk.nbytes)) {
			aes_p8_cbc_encrypt(walk.src.virt.addr,
					   walk.dst.virt.addr,
					   nbytes & AES_BLOCK_MASK,
					   &ctx->dec_key, walk.iv, 0);
			nbytes &= AES_BLOCK_SIZE - 1;
			ret = blkcipher_walk_done(desc, &walk, nbytes);
		}

		pagefault_enable();
		preempt_enable();
	}

	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 = 1000,
	.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 = 0,
			  .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>
	30
	31	#include "aesp8-ppc.h"
	32
	33	struct p8_aes_cbc_ctx {
4beb1060 HX	34	struct crypto_blkcipher *fallback;
	35	struct aes_key enc_key;
	36	struct aes_key dec_key;
8c755ace MC	37	};
	38
	39	static int p8_aes_cbc_init(struct crypto_tfm *tfm)
	40	{
4beb1060 HX	41	const char *alg;
	42	struct crypto_blkcipher *fallback;
	43	struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
	44
	45	if (!(alg = crypto_tfm_alg_name(tfm))) {
	46	printk(KERN_ERR "Failed to get algorithm name.\n");
	47	return -ENOENT;
	48	}
	49
	50	fallback =
	51	crypto_alloc_blkcipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
	52	if (IS_ERR(fallback)) {
	53	printk(KERN_ERR
	54	"Failed to allocate transformation for '%s': %ld\n",
	55	alg, PTR_ERR(fallback));
	56	return PTR_ERR(fallback);
	57	}
	58	printk(KERN_INFO "Using '%s' as fallback implementation.\n",
	59	crypto_tfm_alg_driver_name((struct crypto_tfm *) fallback));
	60
	61	crypto_blkcipher_set_flags(
	62	fallback,
	63	crypto_blkcipher_get_flags((struct crypto_blkcipher *)tfm));
	64	ctx->fallback = fallback;
	65
	66	return 0;
8c755ace MC	67	}
	68
	69	static void p8_aes_cbc_exit(struct crypto_tfm *tfm)
	70	{
4beb1060	71	struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
8c755ace	72
4beb1060 HX	73	if (ctx->fallback) {
	74	crypto_free_blkcipher(ctx->fallback);
	75	ctx->fallback = NULL;
	76	}
8c755ace MC	77	}
	78
	79	static int p8_aes_cbc_setkey(struct crypto_tfm tfm, const u8 key,
4beb1060	80	unsigned int keylen)
8c755ace	81	{
4beb1060 HX	82	int ret;
4beb1060 HX	83	struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
8c755ace	84
44d21c3f	85	preempt_disable();
4beb1060 HX	86	pagefault_disable();
	87	enable_kernel_altivec();
	88	ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
	89	ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
	90	pagefault_enable();
44d21c3f	91	preempt_enable();
8c755ace	92
4beb1060 HX	93	ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
4beb1060 HX	94	return ret;
8c755ace MC	95	}
	96
	97	static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
4beb1060 HX	98	struct scatterlist *dst,
4beb1060 HX	99	struct scatterlist *src, unsigned int nbytes)
8c755ace	100	{
4beb1060 HX	101	int ret;
	102	struct blkcipher_walk walk;
	103	struct p8_aes_cbc_ctx *ctx =
	104	crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
	105	struct blkcipher_desc fallback_desc = {
	106	.tfm = ctx->fallback,
	107	.info = desc->info,
	108	.flags = desc->flags
	109	};
	110
	111	if (in_interrupt()) {
	112	ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src,
	113	nbytes);
	114	} else {
44d21c3f	115	preempt_disable();
4beb1060 HX	116	pagefault_disable();
	117	enable_kernel_altivec();
	118
	119	blkcipher_walk_init(&walk, dst, src, nbytes);
	120	ret = blkcipher_walk_virt(desc, &walk);
	121	while ((nbytes = walk.nbytes)) {
	122	aes_p8_cbc_encrypt(walk.src.virt.addr,
	123	walk.dst.virt.addr,
	124	nbytes & AES_BLOCK_MASK,
	125	&ctx->enc_key, walk.iv, 1);
8c755ace MC	126	nbytes &= AES_BLOCK_SIZE - 1;
8c755ace MC	127	ret = blkcipher_walk_done(desc, &walk, nbytes);
4beb1060	128	}
8c755ace	129
4beb1060	130	pagefault_enable();
44d21c3f	131	preempt_enable();
4beb1060	132	}
8c755ace	133
4beb1060	134	return ret;
8c755ace MC	135	}
	136
	137	static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
4beb1060 HX	138	struct scatterlist *dst,
4beb1060 HX	139	struct scatterlist *src, unsigned int nbytes)
8c755ace	140	{
4beb1060 HX	141	int ret;
	142	struct blkcipher_walk walk;
	143	struct p8_aes_cbc_ctx *ctx =
	144	crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
	145	struct blkcipher_desc fallback_desc = {
	146	.tfm = ctx->fallback,
	147	.info = desc->info,
	148	.flags = desc->flags
	149	};
	150
	151	if (in_interrupt()) {
	152	ret = crypto_blkcipher_decrypt(&fallback_desc, dst, src,
	153	nbytes);
	154	} else {
44d21c3f	155	preempt_disable();
4beb1060 HX	156	pagefault_disable();
	157	enable_kernel_altivec();
	158
	159	blkcipher_walk_init(&walk, dst, src, nbytes);
	160	ret = blkcipher_walk_virt(desc, &walk);
	161	while ((nbytes = walk.nbytes)) {
	162	aes_p8_cbc_encrypt(walk.src.virt.addr,
	163	walk.dst.virt.addr,
	164	nbytes & AES_BLOCK_MASK,
	165	&ctx->dec_key, walk.iv, 0);
8c755ace MC	166	nbytes &= AES_BLOCK_SIZE - 1;
	167	ret = blkcipher_walk_done(desc, &walk, nbytes);
	168	}
	169
4beb1060	170	pagefault_enable();
44d21c3f	171	preempt_enable();
4beb1060	172	}
8c755ace	173
4beb1060	174	return ret;
8c755ace MC	175	}
	176
	177
	178	struct crypto_alg p8_aes_cbc_alg = {
4beb1060 HX	179	.cra_name = "cbc(aes)",
	180	.cra_driver_name = "p8_aes_cbc",
	181	.cra_module = THIS_MODULE,
	182	.cra_priority = 1000,
	183	.cra_type = &crypto_blkcipher_type,
	184	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER \| CRYPTO_ALG_NEED_FALLBACK,
	185	.cra_alignmask = 0,
	186	.cra_blocksize = AES_BLOCK_SIZE,
	187	.cra_ctxsize = sizeof(struct p8_aes_cbc_ctx),
	188	.cra_init = p8_aes_cbc_init,
	189	.cra_exit = p8_aes_cbc_exit,
	190	.cra_blkcipher = {
	191	.ivsize = 0,
	192	.min_keysize = AES_MIN_KEY_SIZE,
	193	.max_keysize = AES_MAX_KEY_SIZE,
	194	.setkey = p8_aes_cbc_setkey,
	195	.encrypt = p8_aes_cbc_encrypt,
	196	.decrypt = p8_aes_cbc_decrypt,
	197	},
8c755ace	198	};