[deliverable/linux.git] / drivers / crypto / vmx / ghash.c

/**
 * GHASH 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/internal/hash.h>
#include <crypto/b128ops.h>

#define IN_INTERRUPT in_interrupt()

#define GHASH_BLOCK_SIZE (16)
#define GHASH_DIGEST_SIZE (16)
#define GHASH_KEY_LEN (16)

void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
		  const u8 *in, size_t len);

struct p8_ghash_ctx {
	u128 htable[16];
	struct crypto_shash *fallback;
};

struct p8_ghash_desc_ctx {
	u64 shash[2];
	u8 buffer[GHASH_DIGEST_SIZE];
	int bytes;
	struct shash_desc fallback_desc;
};

static int p8_ghash_init_tfm(struct crypto_tfm *tfm)
{
	const char *alg;
	struct crypto_shash *fallback;
	struct crypto_shash *shash_tfm = __crypto_shash_cast(tfm);
	struct p8_ghash_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_shash(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(crypto_shash_tfm(fallback)));

	crypto_shash_set_flags(fallback,
			       crypto_shash_get_flags((struct crypto_shash
						       *) tfm));
	ctx->fallback = fallback;

	shash_tfm->descsize = sizeof(struct p8_ghash_desc_ctx)
	    + crypto_shash_descsize(fallback);

	return 0;
}

static void p8_ghash_exit_tfm(struct crypto_tfm *tfm)
{
	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);

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

static int p8_ghash_init(struct shash_desc *desc)
{
	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);

	dctx->bytes = 0;
	memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
	dctx->fallback_desc.tfm = ctx->fallback;
	dctx->fallback_desc.flags = desc->flags;
	return crypto_shash_init(&dctx->fallback_desc);
}

static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
			   unsigned int keylen)
{
	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));

	if (keylen != GHASH_KEY_LEN)
		return -EINVAL;

	preempt_disable();
	pagefault_disable();
	enable_kernel_altivec();
	enable_kernel_fp();
	gcm_init_p8(ctx->htable, (const u64 *) key);
	pagefault_enable();
	preempt_enable();
	return crypto_shash_setkey(ctx->fallback, key, keylen);
}

static int p8_ghash_update(struct shash_desc *desc,
			   const u8 *src, unsigned int srclen)
{
	unsigned int len;
	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);

	if (IN_INTERRUPT) {
		return crypto_shash_update(&dctx->fallback_desc, src,
					   srclen);
	} else {
		if (dctx->bytes) {
			if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
				memcpy(dctx->buffer + dctx->bytes, src,
				       srclen);
				dctx->bytes += srclen;
				return 0;
			}
			memcpy(dctx->buffer + dctx->bytes, src,
			       GHASH_DIGEST_SIZE - dctx->bytes);
			preempt_disable();
			pagefault_disable();
			enable_kernel_altivec();
			enable_kernel_fp();
			gcm_ghash_p8(dctx->shash, ctx->htable,
				     dctx->buffer, GHASH_DIGEST_SIZE);
			pagefault_enable();
			preempt_enable();
			src += GHASH_DIGEST_SIZE - dctx->bytes;
			srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
			dctx->bytes = 0;
		}
		len = srclen & ~(GHASH_DIGEST_SIZE - 1);
		if (len) {
			preempt_disable();
			pagefault_disable();
			enable_kernel_altivec();
			enable_kernel_fp();
			gcm_ghash_p8(dctx->shash, ctx->htable, src, len);
			pagefault_enable();
			preempt_enable();
			src += len;
			srclen -= len;
		}
		if (srclen) {
			memcpy(dctx->buffer, src, srclen);
			dctx->bytes = srclen;
		}
		return 0;
	}
}

static int p8_ghash_final(struct shash_desc *desc, u8 *out)
{
	int i;
	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);

	if (IN_INTERRUPT) {
		return crypto_shash_final(&dctx->fallback_desc, out);
	} else {
		if (dctx->bytes) {
			for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
				dctx->buffer[i] = 0;
			preempt_disable();
			pagefault_disable();
			enable_kernel_altivec();
			enable_kernel_fp();
			gcm_ghash_p8(dctx->shash, ctx->htable,
				     dctx->buffer, GHASH_DIGEST_SIZE);
			pagefault_enable();
			preempt_enable();
			dctx->bytes = 0;
		}
		memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
		return 0;
	}
}

struct shash_alg p8_ghash_alg = {
	.digestsize = GHASH_DIGEST_SIZE,
	.init = p8_ghash_init,
	.update = p8_ghash_update,
	.final = p8_ghash_final,
	.setkey = p8_ghash_setkey,
	.descsize = sizeof(struct p8_ghash_desc_ctx),
	.base = {
		 .cra_name = "ghash",
		 .cra_driver_name = "p8_ghash",
		 .cra_priority = 1000,
		 .cra_flags = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_NEED_FALLBACK,
		 .cra_blocksize = GHASH_BLOCK_SIZE,
		 .cra_ctxsize = sizeof(struct p8_ghash_ctx),
		 .cra_module = THIS_MODULE,
		 .cra_init = p8_ghash_init_tfm,
		 .cra_exit = p8_ghash_exit_tfm,
	},
};
Commit	Line	Data
cc333cd6 MC	1	/**
	2	* GHASH 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	#include <crypto/internal/hash.h>
	31	#include <crypto/b128ops.h>
	32
	33	#define IN_INTERRUPT in_interrupt()
	34
	35	#define GHASH_BLOCK_SIZE (16)
	36	#define GHASH_DIGEST_SIZE (16)
	37	#define GHASH_KEY_LEN (16)
	38
	39	void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
	40	void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
	41	void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
4beb1060	42	const u8 *in, size_t len);
cc333cd6 MC	43
cc333cd6 MC	44	struct p8_ghash_ctx {
4beb1060 HX	45	u128 htable[16];
4beb1060 HX	46	struct crypto_shash *fallback;
cc333cd6 MC	47	};
	48
	49	struct p8_ghash_desc_ctx {
4beb1060 HX	50	u64 shash[2];
	51	u8 buffer[GHASH_DIGEST_SIZE];
	52	int bytes;
	53	struct shash_desc fallback_desc;
cc333cd6 MC	54	};
	55
	56	static int p8_ghash_init_tfm(struct crypto_tfm *tfm)
	57	{
4beb1060 HX	58	const char *alg;
	59	struct crypto_shash *fallback;
	60	struct crypto_shash *shash_tfm = __crypto_shash_cast(tfm);
	61	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
	62
	63	if (!(alg = crypto_tfm_alg_name(tfm))) {
	64	printk(KERN_ERR "Failed to get algorithm name.\n");
	65	return -ENOENT;
	66	}
	67
	68	fallback = crypto_alloc_shash(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
	69	if (IS_ERR(fallback)) {
	70	printk(KERN_ERR
	71	"Failed to allocate transformation for '%s': %ld\n",
	72	alg, PTR_ERR(fallback));
	73	return PTR_ERR(fallback);
	74	}
	75	printk(KERN_INFO "Using '%s' as fallback implementation.\n",
	76	crypto_tfm_alg_driver_name(crypto_shash_tfm(fallback)));
	77
	78	crypto_shash_set_flags(fallback,
	79	crypto_shash_get_flags((struct crypto_shash
	80	*) tfm));
	81	ctx->fallback = fallback;
	82
	83	shash_tfm->descsize = sizeof(struct p8_ghash_desc_ctx)
	84	+ crypto_shash_descsize(fallback);
	85
	86	return 0;
cc333cd6 MC	87	}
	88
	89	static void p8_ghash_exit_tfm(struct crypto_tfm *tfm)
	90	{
4beb1060	91	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
cc333cd6	92
4beb1060 HX	93	if (ctx->fallback) {
	94	crypto_free_shash(ctx->fallback);
	95	ctx->fallback = NULL;
	96	}
cc333cd6 MC	97	}
	98
	99	static int p8_ghash_init(struct shash_desc *desc)
	100	{
4beb1060 HX	101	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
	102	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	103
	104	dctx->bytes = 0;
	105	memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
	106	dctx->fallback_desc.tfm = ctx->fallback;
	107	dctx->fallback_desc.flags = desc->flags;
	108	return crypto_shash_init(&dctx->fallback_desc);
cc333cd6 MC	109	}
	110
	111	static int p8_ghash_setkey(struct crypto_shash tfm, const u8 key,
4beb1060	112	unsigned int keylen)
cc333cd6	113	{
4beb1060	114	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));
cc333cd6	115
4beb1060 HX	116	if (keylen != GHASH_KEY_LEN)
4beb1060 HX	117	return -EINVAL;
cc333cd6	118
44d21c3f	119	preempt_disable();
4beb1060 HX	120	pagefault_disable();
	121	enable_kernel_altivec();
	122	enable_kernel_fp();
	123	gcm_init_p8(ctx->htable, (const u64 *) key);
	124	pagefault_enable();
44d21c3f	125	preempt_enable();
4beb1060	126	return crypto_shash_setkey(ctx->fallback, key, keylen);
cc333cd6 MC	127	}
	128
	129	static int p8_ghash_update(struct shash_desc *desc,
4beb1060	130	const u8 *src, unsigned int srclen)
cc333cd6	131	{
4beb1060 HX	132	unsigned int len;
	133	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
	134	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	135
	136	if (IN_INTERRUPT) {
	137	return crypto_shash_update(&dctx->fallback_desc, src,
	138	srclen);
	139	} else {
	140	if (dctx->bytes) {
	141	if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
	142	memcpy(dctx->buffer + dctx->bytes, src,
	143	srclen);
	144	dctx->bytes += srclen;
	145	return 0;
	146	}
	147	memcpy(dctx->buffer + dctx->bytes, src,
	148	GHASH_DIGEST_SIZE - dctx->bytes);
44d21c3f	149	preempt_disable();
4beb1060 HX	150	pagefault_disable();
	151	enable_kernel_altivec();
	152	enable_kernel_fp();
	153	gcm_ghash_p8(dctx->shash, ctx->htable,
	154	dctx->buffer, GHASH_DIGEST_SIZE);
	155	pagefault_enable();
44d21c3f	156	preempt_enable();
4beb1060 HX	157	src += GHASH_DIGEST_SIZE - dctx->bytes;
	158	srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
	159	dctx->bytes = 0;
	160	}
	161	len = srclen & ~(GHASH_DIGEST_SIZE - 1);
	162	if (len) {
44d21c3f	163	preempt_disable();
4beb1060 HX	164	pagefault_disable();
	165	enable_kernel_altivec();
	166	enable_kernel_fp();
	167	gcm_ghash_p8(dctx->shash, ctx->htable, src, len);
	168	pagefault_enable();
44d21c3f	169	preempt_enable();
4beb1060 HX	170	src += len;
	171	srclen -= len;
	172	}
	173	if (srclen) {
	174	memcpy(dctx->buffer, src, srclen);
	175	dctx->bytes = srclen;
	176	}
	177	return 0;
	178	}
cc333cd6 MC	179	}
	180
	181	static int p8_ghash_final(struct shash_desc desc, u8 out)
	182	{
4beb1060 HX	183	int i;
	184	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
	185	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
	186
	187	if (IN_INTERRUPT) {
	188	return crypto_shash_final(&dctx->fallback_desc, out);
	189	} else {
	190	if (dctx->bytes) {
	191	for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
	192	dctx->buffer[i] = 0;
44d21c3f	193	preempt_disable();
4beb1060 HX	194	pagefault_disable();
	195	enable_kernel_altivec();
	196	enable_kernel_fp();
	197	gcm_ghash_p8(dctx->shash, ctx->htable,
	198	dctx->buffer, GHASH_DIGEST_SIZE);
	199	pagefault_enable();
44d21c3f	200	preempt_enable();
4beb1060 HX	201	dctx->bytes = 0;
	202	}
	203	memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
	204	return 0;
	205	}
cc333cd6 MC	206	}
	207
	208	struct shash_alg p8_ghash_alg = {
4beb1060 HX	209	.digestsize = GHASH_DIGEST_SIZE,
	210	.init = p8_ghash_init,
	211	.update = p8_ghash_update,
	212	.final = p8_ghash_final,
	213	.setkey = p8_ghash_setkey,
	214	.descsize = sizeof(struct p8_ghash_desc_ctx),
	215	.base = {
	216	.cra_name = "ghash",
	217	.cra_driver_name = "p8_ghash",
	218	.cra_priority = 1000,
	219	.cra_flags = CRYPTO_ALG_TYPE_SHASH \| CRYPTO_ALG_NEED_FALLBACK,
	220	.cra_blocksize = GHASH_BLOCK_SIZE,
	221	.cra_ctxsize = sizeof(struct p8_ghash_ctx),
	222	.cra_module = THIS_MODULE,
	223	.cra_init = p8_ghash_init_tfm,
	224	.cra_exit = p8_ghash_exit_tfm,
	225	},
cc333cd6	226	};