[linux.git] / block / t10-pi.c

/*
 * t10_pi.c - Functions for generating and verifying T10 Protection
 *	      Information.
 *
 * Copyright (C) 2007, 2008, 2014 Oracle Corporation
 * Written by: Martin K. Petersen <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * 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; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
 * USA.
 *
 */

#include <linux/t10-pi.h>
#include <linux/blkdev.h>
#include <linux/crc-t10dif.h>
#include <net/checksum.h>

typedef __be16 (csum_fn) (void *, unsigned int);

static __be16 t10_pi_crc_fn(void *data, unsigned int len)
{
	return cpu_to_be16(crc_t10dif(data, len));
}

static __be16 t10_pi_ip_fn(void *data, unsigned int len)
{
	return (__force __be16)ip_compute_csum(data, len);
}

/*
 * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
 * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
 * tag.
 */
static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
		csum_fn *fn, unsigned int type)
{
	unsigned int i;

	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
		struct t10_pi_tuple *pi = iter->prot_buf;

		pi->guard_tag = fn(iter->data_buf, iter->interval);
		pi->app_tag = 0;

		if (type == 1)
			pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
		else
			pi->ref_tag = 0;

		iter->data_buf += iter->interval;
		iter->prot_buf += sizeof(struct t10_pi_tuple);
		iter->seed++;
	}

	return BLK_STS_OK;
}

static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
		csum_fn *fn, unsigned int type)
{
	unsigned int i;

	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
		struct t10_pi_tuple *pi = iter->prot_buf;
		__be16 csum;

		switch (type) {
		case 1:
		case 2:
			if (pi->app_tag == T10_PI_APP_ESCAPE)
				goto next;

			if (be32_to_cpu(pi->ref_tag) !=
			    lower_32_bits(iter->seed)) {
				pr_err("%s: ref tag error at location %llu " \
				       "(rcvd %u)\n", iter->disk_name,
				       (unsigned long long)
				       iter->seed, be32_to_cpu(pi->ref_tag));
				return BLK_STS_PROTECTION;
			}
			break;
		case 3:
			if (pi->app_tag == T10_PI_APP_ESCAPE &&
			    pi->ref_tag == T10_PI_REF_ESCAPE)
				goto next;
			break;
		}

		csum = fn(iter->data_buf, iter->interval);

		if (pi->guard_tag != csum) {
			pr_err("%s: guard tag error at sector %llu " \
			       "(rcvd %04x, want %04x)\n", iter->disk_name,
			       (unsigned long long)iter->seed,
			       be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
			return BLK_STS_PROTECTION;
		}

next:
		iter->data_buf += iter->interval;
		iter->prot_buf += sizeof(struct t10_pi_tuple);
		iter->seed++;
	}

	return BLK_STS_OK;
}

static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
{
	return t10_pi_generate(iter, t10_pi_crc_fn, 1);
}

static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
{
	return t10_pi_generate(iter, t10_pi_ip_fn, 1);
}

static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
{
	return t10_pi_verify(iter, t10_pi_crc_fn, 1);
}

static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
{
	return t10_pi_verify(iter, t10_pi_ip_fn, 1);
}

static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
{
	return t10_pi_generate(iter, t10_pi_crc_fn, 3);
}

static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
{
	return t10_pi_generate(iter, t10_pi_ip_fn, 3);
}

static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
{
	return t10_pi_verify(iter, t10_pi_crc_fn, 3);
}

static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
{
	return t10_pi_verify(iter, t10_pi_ip_fn, 3);
}

const struct blk_integrity_profile t10_pi_type1_crc = {
	.name			= "T10-DIF-TYPE1-CRC",
	.generate_fn		= t10_pi_type1_generate_crc,
	.verify_fn		= t10_pi_type1_verify_crc,
};
EXPORT_SYMBOL(t10_pi_type1_crc);

const struct blk_integrity_profile t10_pi_type1_ip = {
	.name			= "T10-DIF-TYPE1-IP",
	.generate_fn		= t10_pi_type1_generate_ip,
	.verify_fn		= t10_pi_type1_verify_ip,
};
EXPORT_SYMBOL(t10_pi_type1_ip);

const struct blk_integrity_profile t10_pi_type3_crc = {
	.name			= "T10-DIF-TYPE3-CRC",
	.generate_fn		= t10_pi_type3_generate_crc,
	.verify_fn		= t10_pi_type3_verify_crc,
};
EXPORT_SYMBOL(t10_pi_type3_crc);

const struct blk_integrity_profile t10_pi_type3_ip = {
	.name			= "T10-DIF-TYPE3-IP",
	.generate_fn		= t10_pi_type3_generate_ip,
	.verify_fn		= t10_pi_type3_verify_ip,
};
EXPORT_SYMBOL(t10_pi_type3_ip);

/**
 * t10_pi_prepare - prepare PI prior submitting request to device
 * @rq:              request with PI that should be prepared
 * @protection_type: PI type (Type 1/Type 2/Type 3)
 *
 * For Type 1/Type 2, the virtual start sector is the one that was
 * originally submitted by the block layer for the ref_tag usage. Due to
 * partitioning, MD/DM cloning, etc. the actual physical start sector is
 * likely to be different. Remap protection information to match the
 * physical LBA.
 *
 * Type 3 does not have a reference tag so no remapping is required.
 */
void t10_pi_prepare(struct request *rq, u8 protection_type)
{
	const int tuple_sz = rq->q->integrity.tuple_size;
	u32 ref_tag = t10_pi_ref_tag(rq);
	struct bio *bio;

	if (protection_type == T10_PI_TYPE3_PROTECTION)
		return;

	__rq_for_each_bio(bio, rq) {
		struct bio_integrity_payload *bip = bio_integrity(bio);
		u32 virt = bip_get_seed(bip) & 0xffffffff;
		struct bio_vec iv;
		struct bvec_iter iter;

		/* Already remapped? */
		if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
			break;

		bip_for_each_vec(iv, bip, iter) {
			void *p, *pmap;
			unsigned int j;

			pmap = kmap_atomic(iv.bv_page);
			p = pmap + iv.bv_offset;
			for (j = 0; j < iv.bv_len; j += tuple_sz) {
				struct t10_pi_tuple *pi = p;

				if (be32_to_cpu(pi->ref_tag) == virt)
					pi->ref_tag = cpu_to_be32(ref_tag);
				virt++;
				ref_tag++;
				p += tuple_sz;
			}

			kunmap_atomic(pmap);
		}

		bip->bip_flags |= BIP_MAPPED_INTEGRITY;
	}
}
EXPORT_SYMBOL(t10_pi_prepare);

/**
 * t10_pi_complete - prepare PI prior returning request to the block layer
 * @rq:              request with PI that should be prepared
 * @protection_type: PI type (Type 1/Type 2/Type 3)
 * @intervals:       total elements to prepare
 *
 * For Type 1/Type 2, the virtual start sector is the one that was
 * originally submitted by the block layer for the ref_tag usage. Due to
 * partitioning, MD/DM cloning, etc. the actual physical start sector is
 * likely to be different. Since the physical start sector was submitted
 * to the device, we should remap it back to virtual values expected by the
 * block layer.
 *
 * Type 3 does not have a reference tag so no remapping is required.
 */
void t10_pi_complete(struct request *rq, u8 protection_type,
		     unsigned int intervals)
{
	const int tuple_sz = rq->q->integrity.tuple_size;
	u32 ref_tag = t10_pi_ref_tag(rq);
	struct bio *bio;

	if (protection_type == T10_PI_TYPE3_PROTECTION)
		return;

	__rq_for_each_bio(bio, rq) {
		struct bio_integrity_payload *bip = bio_integrity(bio);
		u32 virt = bip_get_seed(bip) & 0xffffffff;
		struct bio_vec iv;
		struct bvec_iter iter;

		bip_for_each_vec(iv, bip, iter) {
			void *p, *pmap;
			unsigned int j;

			pmap = kmap_atomic(iv.bv_page);
			p = pmap + iv.bv_offset;
			for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
				struct t10_pi_tuple *pi = p;

				if (be32_to_cpu(pi->ref_tag) == ref_tag)
					pi->ref_tag = cpu_to_be32(virt);
				virt++;
				ref_tag++;
				intervals--;
				p += tuple_sz;
			}

			kunmap_atomic(pmap);
		}
	}
}
EXPORT_SYMBOL(t10_pi_complete);
Commit	Line	Data
2341c2f8 MP	1	/*
	2	* t10_pi.c - Functions for generating and verifying T10 Protection
	3	* Information.
	4	*
	5	* Copyright (C) 2007, 2008, 2014 Oracle Corporation
	6	* Written by: Martin K. Petersen <[email protected]>
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License version
	10	* 2 as published by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; see the file COPYING. If not, write to
	19	* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
	20	* USA.
	21	*
	22	*/
	23
	24	#include <linux/t10-pi.h>
	25	#include <linux/blkdev.h>
	26	#include <linux/crc-t10dif.h>
	27	#include <net/checksum.h>
	28
	29	typedef __be16 (csum_fn) (void *, unsigned int);
	30
2341c2f8 MP	31	static __be16 t10_pi_crc_fn(void *data, unsigned int len)
	32	{
	33	return cpu_to_be16(crc_t10dif(data, len));
	34	}
	35
	36	static __be16 t10_pi_ip_fn(void *data, unsigned int len)
	37	{
	38	return (__force __be16)ip_compute_csum(data, len);
	39	}
	40
	41	/*
	42	* Type 1 and Type 2 protection use the same format: 16 bit guard tag,
	43	* 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
	44	* tag.
	45	*/
4e4cbee9 CH	46	static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
4e4cbee9 CH	47	csum_fn *fn, unsigned int type)
2341c2f8 MP	48	{
	49	unsigned int i;
	50
	51	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
	52	struct t10_pi_tuple *pi = iter->prot_buf;
	53
	54	pi->guard_tag = fn(iter->data_buf, iter->interval);
	55	pi->app_tag = 0;
	56
	57	if (type == 1)
	58	pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
	59	else
	60	pi->ref_tag = 0;
	61
	62	iter->data_buf += iter->interval;
	63	iter->prot_buf += sizeof(struct t10_pi_tuple);
	64	iter->seed++;
	65	}
	66
4e4cbee9	67	return BLK_STS_OK;
2341c2f8 MP	68	}
2341c2f8 MP	69
4e4cbee9 CH	70	static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
4e4cbee9 CH	71	csum_fn *fn, unsigned int type)
2341c2f8 MP	72	{
	73	unsigned int i;
	74
	75	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
	76	struct t10_pi_tuple *pi = iter->prot_buf;
	77	__be16 csum;
	78
	79	switch (type) {
	80	case 1:
	81	case 2:
128b6f9f	82	if (pi->app_tag == T10_PI_APP_ESCAPE)
2341c2f8 MP	83	goto next;
	84
	85	if (be32_to_cpu(pi->ref_tag) !=
	86	lower_32_bits(iter->seed)) {
	87	pr_err("%s: ref tag error at location %llu " \
	88	"(rcvd %u)\n", iter->disk_name,
	89	(unsigned long long)
	90	iter->seed, be32_to_cpu(pi->ref_tag));
a462b950	91	return BLK_STS_PROTECTION;
2341c2f8 MP	92	}
	93	break;
	94	case 3:
128b6f9f DM	95	if (pi->app_tag == T10_PI_APP_ESCAPE &&
128b6f9f DM	96	pi->ref_tag == T10_PI_REF_ESCAPE)
2341c2f8 MP	97	goto next;
	98	break;
	99	}
	100
	101	csum = fn(iter->data_buf, iter->interval);
	102
	103	if (pi->guard_tag != csum) {
	104	pr_err("%s: guard tag error at sector %llu " \
	105	"(rcvd %04x, want %04x)\n", iter->disk_name,
	106	(unsigned long long)iter->seed,
	107	be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
4e4cbee9	108	return BLK_STS_PROTECTION;
2341c2f8 MP	109	}
	110
	111	next:
	112	iter->data_buf += iter->interval;
	113	iter->prot_buf += sizeof(struct t10_pi_tuple);
	114	iter->seed++;
	115	}
	116
4e4cbee9	117	return BLK_STS_OK;
2341c2f8 MP	118	}
2341c2f8 MP	119
4e4cbee9	120	static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
2341c2f8 MP	121	{
	122	return t10_pi_generate(iter, t10_pi_crc_fn, 1);
	123	}
	124
4e4cbee9	125	static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
2341c2f8 MP	126	{
	127	return t10_pi_generate(iter, t10_pi_ip_fn, 1);
	128	}
	129
4e4cbee9	130	static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
2341c2f8 MP	131	{
	132	return t10_pi_verify(iter, t10_pi_crc_fn, 1);
	133	}
	134
4e4cbee9	135	static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
2341c2f8 MP	136	{
	137	return t10_pi_verify(iter, t10_pi_ip_fn, 1);
	138	}
	139
4e4cbee9	140	static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
2341c2f8 MP	141	{
	142	return t10_pi_generate(iter, t10_pi_crc_fn, 3);
	143	}
	144
4e4cbee9	145	static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
2341c2f8 MP	146	{
	147	return t10_pi_generate(iter, t10_pi_ip_fn, 3);
	148	}
	149
4e4cbee9	150	static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
2341c2f8 MP	151	{
	152	return t10_pi_verify(iter, t10_pi_crc_fn, 3);
	153	}
	154
4e4cbee9	155	static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
2341c2f8 MP	156	{
	157	return t10_pi_verify(iter, t10_pi_ip_fn, 3);
	158	}
	159
869ab90f	160	const struct blk_integrity_profile t10_pi_type1_crc = {
2341c2f8 MP	161	.name = "T10-DIF-TYPE1-CRC",
	162	.generate_fn = t10_pi_type1_generate_crc,
	163	.verify_fn = t10_pi_type1_verify_crc,
2341c2f8 MP	164	};
	165	EXPORT_SYMBOL(t10_pi_type1_crc);
	166
869ab90f	167	const struct blk_integrity_profile t10_pi_type1_ip = {
2341c2f8 MP	168	.name = "T10-DIF-TYPE1-IP",
	169	.generate_fn = t10_pi_type1_generate_ip,
	170	.verify_fn = t10_pi_type1_verify_ip,
2341c2f8 MP	171	};
	172	EXPORT_SYMBOL(t10_pi_type1_ip);
	173
869ab90f	174	const struct blk_integrity_profile t10_pi_type3_crc = {
2341c2f8 MP	175	.name = "T10-DIF-TYPE3-CRC",
	176	.generate_fn = t10_pi_type3_generate_crc,
	177	.verify_fn = t10_pi_type3_verify_crc,
2341c2f8 MP	178	};
	179	EXPORT_SYMBOL(t10_pi_type3_crc);
	180
869ab90f	181	const struct blk_integrity_profile t10_pi_type3_ip = {
2341c2f8 MP	182	.name = "T10-DIF-TYPE3-IP",
	183	.generate_fn = t10_pi_type3_generate_ip,
	184	.verify_fn = t10_pi_type3_verify_ip,
2341c2f8 MP	185	};
2341c2f8 MP	186	EXPORT_SYMBOL(t10_pi_type3_ip);
10c41ddd MG	187
	188	/**
	189	* t10_pi_prepare - prepare PI prior submitting request to device
	190	* @rq: request with PI that should be prepared
	191	* @protection_type: PI type (Type 1/Type 2/Type 3)
	192	*
	193	* For Type 1/Type 2, the virtual start sector is the one that was
	194	* originally submitted by the block layer for the ref_tag usage. Due to
	195	* partitioning, MD/DM cloning, etc. the actual physical start sector is
	196	* likely to be different. Remap protection information to match the
	197	* physical LBA.
	198	*
	199	* Type 3 does not have a reference tag so no remapping is required.
	200	*/
	201	void t10_pi_prepare(struct request *rq, u8 protection_type)
	202	{
	203	const int tuple_sz = rq->q->integrity.tuple_size;
	204	u32 ref_tag = t10_pi_ref_tag(rq);
	205	struct bio *bio;
	206
	207	if (protection_type == T10_PI_TYPE3_PROTECTION)
	208	return;
	209
	210	__rq_for_each_bio(bio, rq) {
	211	struct bio_integrity_payload *bip = bio_integrity(bio);
	212	u32 virt = bip_get_seed(bip) & 0xffffffff;
	213	struct bio_vec iv;
	214	struct bvec_iter iter;
	215
	216	/* Already remapped? */
	217	if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
	218	break;
	219
	220	bip_for_each_vec(iv, bip, iter) {
	221	void p, pmap;
	222	unsigned int j;
	223
	224	pmap = kmap_atomic(iv.bv_page);
	225	p = pmap + iv.bv_offset;
	226	for (j = 0; j < iv.bv_len; j += tuple_sz) {
	227	struct t10_pi_tuple *pi = p;
	228
	229	if (be32_to_cpu(pi->ref_tag) == virt)
	230	pi->ref_tag = cpu_to_be32(ref_tag);
	231	virt++;
	232	ref_tag++;
	233	p += tuple_sz;
	234	}
	235
	236	kunmap_atomic(pmap);
	237	}
	238
	239	bip->bip_flags \|= BIP_MAPPED_INTEGRITY;
	240	}
	241	}
	242	EXPORT_SYMBOL(t10_pi_prepare);
	243
	244	/**
	245	* t10_pi_complete - prepare PI prior returning request to the block layer
	246	* @rq: request with PI that should be prepared
	247	* @protection_type: PI type (Type 1/Type 2/Type 3)
	248	* @intervals: total elements to prepare
	249	*
	250	* For Type 1/Type 2, the virtual start sector is the one that was
251	* originally submitted by the block layer for the ref_tag usage. Due to
252	* partitioning, MD/DM cloning, etc. the actual physical start sector is
253	* likely to be different. Since the physical start sector was submitted
254	* to the device, we should remap it back to virtual values expected by the
255	* block layer.
256	*
257	* Type 3 does not have a reference tag so no remapping is required.
258	*/
259	void t10_pi_complete(struct request *rq, u8 protection_type,
260	unsigned int intervals)
261	{
262	const int tuple_sz = rq->q->integrity.tuple_size;
263	u32 ref_tag = t10_pi_ref_tag(rq);
264	struct bio *bio;
265
266	if (protection_type == T10_PI_TYPE3_PROTECTION)
267	return;
268
269	__rq_for_each_bio(bio, rq) {
270	struct bio_integrity_payload *bip = bio_integrity(bio);
271	u32 virt = bip_get_seed(bip) & 0xffffffff;
272	struct bio_vec iv;
273	struct bvec_iter iter;
274
275	bip_for_each_vec(iv, bip, iter) {
276	void p, pmap;
277	unsigned int j;
278
279	pmap = kmap_atomic(iv.bv_page);
280	p = pmap + iv.bv_offset;
281	for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
282	struct t10_pi_tuple *pi = p;
283
284	if (be32_to_cpu(pi->ref_tag) == ref_tag)
285	pi->ref_tag = cpu_to_be32(virt);
286	virt++;
287	ref_tag++;
288	intervals--;
289	p += tuple_sz;
290	}
291
292	kunmap_atomic(pmap);
293	}
294	}
295	}
296	EXPORT_SYMBOL(t10_pi_complete);