[GitHub/mt8127/android_kernel_alcatel_ttab.git] / block / blk-integrity.c

/*
 * blk-integrity.c - Block layer data integrity extensions
 *
 * Copyright (C) 2007, 2008 Oracle Corporation
 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
 *
 * 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/blkdev.h>
#include <linux/mempool.h>
#include <linux/bio.h>
#include <linux/scatterlist.h>
#include <linux/export.h>
#include <linux/slab.h>

#include "blk.h"

static struct kmem_cache *integrity_cachep;

static const char *bi_unsupported_name = "unsupported";

/**
 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
 * @q:		request queue
 * @bio:	bio with integrity metadata attached
 *
 * Description: Returns the number of elements required in a
 * scatterlist corresponding to the integrity metadata in a bio.
 */
int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
{
	struct bio_vec *iv, *ivprv = NULL;
	unsigned int segments = 0;
	unsigned int seg_size = 0;
	unsigned int i = 0;

	bio_for_each_integrity_vec(iv, bio, i) {

		if (ivprv) {
			if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
				goto new_segment;

			if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
				goto new_segment;

			if (seg_size + iv->bv_len > queue_max_segment_size(q))
				goto new_segment;

			seg_size += iv->bv_len;
		} else {
new_segment:
			segments++;
			seg_size = iv->bv_len;
		}

		ivprv = iv;
	}

	return segments;
}
EXPORT_SYMBOL(blk_rq_count_integrity_sg);

/**
 * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
 * @q:		request queue
 * @bio:	bio with integrity metadata attached
 * @sglist:	target scatterlist
 *
 * Description: Map the integrity vectors in request into a
 * scatterlist.  The scatterlist must be big enough to hold all
 * elements.  I.e. sized using blk_rq_count_integrity_sg().
 */
int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
			    struct scatterlist *sglist)
{
	struct bio_vec *iv, *ivprv = NULL;
	struct scatterlist *sg = NULL;
	unsigned int segments = 0;
	unsigned int i = 0;

	bio_for_each_integrity_vec(iv, bio, i) {

		if (ivprv) {
			if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
				goto new_segment;

			if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
				goto new_segment;

			if (sg->length + iv->bv_len > queue_max_segment_size(q))
				goto new_segment;

			sg->length += iv->bv_len;
		} else {
new_segment:
			if (!sg)
				sg = sglist;
			else {
				sg_unmark_end(sg);
				sg = sg_next(sg);
			}

			sg_set_page(sg, iv->bv_page, iv->bv_len, iv->bv_offset);
			segments++;
		}

		ivprv = iv;
	}

	if (sg)
		sg_mark_end(sg);

	return segments;
}
EXPORT_SYMBOL(blk_rq_map_integrity_sg);

/**
 * blk_integrity_compare - Compare integrity profile of two disks
 * @gd1:	Disk to compare
 * @gd2:	Disk to compare
 *
 * Description: Meta-devices like DM and MD need to verify that all
 * sub-devices use the same integrity format before advertising to
 * upper layers that they can send/receive integrity metadata.  This
 * function can be used to check whether two gendisk devices have
 * compatible integrity formats.
 */
int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
{
	struct blk_integrity *b1 = gd1->integrity;
	struct blk_integrity *b2 = gd2->integrity;

	if (!b1 && !b2)
		return 0;

	if (!b1 || !b2)
		return -1;

	if (b1->sector_size != b2->sector_size) {
		printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
		       gd1->disk_name, gd2->disk_name,
		       b1->sector_size, b2->sector_size);
		return -1;
	}

	if (b1->tuple_size != b2->tuple_size) {
		printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
		       gd1->disk_name, gd2->disk_name,
		       b1->tuple_size, b2->tuple_size);
		return -1;
	}

	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
		printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
		       gd1->disk_name, gd2->disk_name,
		       b1->tag_size, b2->tag_size);
		return -1;
	}

	if (strcmp(b1->name, b2->name)) {
		printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
		       gd1->disk_name, gd2->disk_name,
		       b1->name, b2->name);
		return -1;
	}

	return 0;
}
EXPORT_SYMBOL(blk_integrity_compare);

int blk_integrity_merge_rq(struct request_queue *q, struct request *req,
			   struct request *next)
{
	if (blk_integrity_rq(req) != blk_integrity_rq(next))
		return -1;

	if (req->nr_integrity_segments + next->nr_integrity_segments >
	    q->limits.max_integrity_segments)
		return -1;

	return 0;
}
EXPORT_SYMBOL(blk_integrity_merge_rq);

int blk_integrity_merge_bio(struct request_queue *q, struct request *req,
			    struct bio *bio)
{
	int nr_integrity_segs;
	struct bio *next = bio->bi_next;

	bio->bi_next = NULL;
	nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
	bio->bi_next = next;

	if (req->nr_integrity_segments + nr_integrity_segs >
	    q->limits.max_integrity_segments)
		return -1;

	req->nr_integrity_segments += nr_integrity_segs;

	return 0;
}
EXPORT_SYMBOL(blk_integrity_merge_bio);

struct integrity_sysfs_entry {
	struct attribute attr;
	ssize_t (*show)(struct blk_integrity *, char *);
	ssize_t (*store)(struct blk_integrity *, const char *, size_t);
};

static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
				   char *page)
{
	struct blk_integrity *bi =
		container_of(kobj, struct blk_integrity, kobj);
	struct integrity_sysfs_entry *entry =
		container_of(attr, struct integrity_sysfs_entry, attr);

	return entry->show(bi, page);
}

static ssize_t integrity_attr_store(struct kobject *kobj,
				    struct attribute *attr, const char *page,
				    size_t count)
{
	struct blk_integrity *bi =
		container_of(kobj, struct blk_integrity, kobj);
	struct integrity_sysfs_entry *entry =
		container_of(attr, struct integrity_sysfs_entry, attr);
	ssize_t ret = 0;

	if (entry->store)
		ret = entry->store(bi, page, count);

	return ret;
}

static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
{
	if (bi != NULL && bi->name != NULL)
		return sprintf(page, "%s\n", bi->name);
	else
		return sprintf(page, "none\n");
}

static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
{
	if (bi != NULL)
		return sprintf(page, "%u\n", bi->tag_size);
	else
		return sprintf(page, "0\n");
}

static ssize_t integrity_read_store(struct blk_integrity *bi,
				    const char *page, size_t count)
{
	char *p = (char *) page;
	unsigned long val = simple_strtoul(p, &p, 10);

	if (val)
		bi->flags |= INTEGRITY_FLAG_READ;
	else
		bi->flags &= ~INTEGRITY_FLAG_READ;

	return count;
}

static ssize_t integrity_read_show(struct blk_integrity *bi, char *page)
{
	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 0);
}

static ssize_t integrity_write_store(struct blk_integrity *bi,
				     const char *page, size_t count)
{
	char *p = (char *) page;
	unsigned long val = simple_strtoul(p, &p, 10);

	if (val)
		bi->flags |= INTEGRITY_FLAG_WRITE;
	else
		bi->flags &= ~INTEGRITY_FLAG_WRITE;

	return count;
}

static ssize_t integrity_write_show(struct blk_integrity *bi, char *page)
{
	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 0);
}

static struct integrity_sysfs_entry integrity_format_entry = {
	.attr = { .name = "format", .mode = S_IRUGO },
	.show = integrity_format_show,
};

static struct integrity_sysfs_entry integrity_tag_size_entry = {
	.attr = { .name = "tag_size", .mode = S_IRUGO },
	.show = integrity_tag_size_show,
};

static struct integrity_sysfs_entry integrity_read_entry = {
	.attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
	.show = integrity_read_show,
	.store = integrity_read_store,
};

static struct integrity_sysfs_entry integrity_write_entry = {
	.attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
	.show = integrity_write_show,
	.store = integrity_write_store,
};

static struct attribute *integrity_attrs[] = {
	&integrity_format_entry.attr,
	&integrity_tag_size_entry.attr,
	&integrity_read_entry.attr,
	&integrity_write_entry.attr,
	NULL,
};

static const struct sysfs_ops integrity_ops = {
	.show	= &integrity_attr_show,
	.store	= &integrity_attr_store,
};

static int __init blk_dev_integrity_init(void)
{
	integrity_cachep = kmem_cache_create("blkdev_integrity",
					     sizeof(struct blk_integrity),
					     0, SLAB_PANIC, NULL);
	return 0;
}
subsys_initcall(blk_dev_integrity_init);

static void blk_integrity_release(struct kobject *kobj)
{
	struct blk_integrity *bi =
		container_of(kobj, struct blk_integrity, kobj);

	kmem_cache_free(integrity_cachep, bi);
}

static struct kobj_type integrity_ktype = {
	.default_attrs	= integrity_attrs,
	.sysfs_ops	= &integrity_ops,
	.release	= blk_integrity_release,
};

bool blk_integrity_is_initialized(struct gendisk *disk)
{
	struct blk_integrity *bi = blk_get_integrity(disk);

	return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
}
EXPORT_SYMBOL(blk_integrity_is_initialized);

/**
 * blk_integrity_register - Register a gendisk as being integrity-capable
 * @disk:	struct gendisk pointer to make integrity-aware
 * @template:	optional integrity profile to register
 *
 * Description: When a device needs to advertise itself as being able
 * to send/receive integrity metadata it must use this function to
 * register the capability with the block layer.  The template is a
 * blk_integrity struct with values appropriate for the underlying
 * hardware.  If template is NULL the new profile is allocated but
 * not filled out. See Documentation/block/data-integrity.txt.
 */
int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
{
	struct blk_integrity *bi;

	BUG_ON(disk == NULL);

	if (disk->integrity == NULL) {
		bi = kmem_cache_alloc(integrity_cachep,
				      GFP_KERNEL | __GFP_ZERO);
		if (!bi)
			return -1;

		if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
					 &disk_to_dev(disk)->kobj,
					 "%s", "integrity")) {
			kmem_cache_free(integrity_cachep, bi);
			return -1;
		}

		kobject_uevent(&bi->kobj, KOBJ_ADD);

		bi->flags |= INTEGRITY_FLAG_READ | INTEGRITY_FLAG_WRITE;
		bi->sector_size = queue_logical_block_size(disk->queue);
		disk->integrity = bi;
	} else
		bi = disk->integrity;

	/* Use the provided profile as template */
	if (template != NULL) {
		bi->name = template->name;
		bi->generate_fn = template->generate_fn;
		bi->verify_fn = template->verify_fn;
		bi->tuple_size = template->tuple_size;
		bi->set_tag_fn = template->set_tag_fn;
		bi->get_tag_fn = template->get_tag_fn;
		bi->tag_size = template->tag_size;
	} else
		bi->name = bi_unsupported_name;

	disk->queue->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;

	return 0;
}
EXPORT_SYMBOL(blk_integrity_register);

/**
 * blk_integrity_unregister - Remove block integrity profile
 * @disk:	disk whose integrity profile to deallocate
 *
 * Description: This function frees all memory used by the block
 * integrity profile.  To be called at device teardown.
 */
void blk_integrity_unregister(struct gendisk *disk)
{
	struct blk_integrity *bi;

	if (!disk || !disk->integrity)
		return;

	disk->queue->backing_dev_info.capabilities &= ~BDI_CAP_STABLE_WRITES;

	bi = disk->integrity;

	kobject_uevent(&bi->kobj, KOBJ_REMOVE);
	kobject_del(&bi->kobj);
	kobject_put(&bi->kobj);
	disk->integrity = NULL;
}
EXPORT_SYMBOL(blk_integrity_unregister);
Commit	Line	Data
7ba1ba12 MP	1	/*
	2	* blk-integrity.c - Block layer data integrity extensions
	3	*
	4	* Copyright (C) 2007, 2008 Oracle Corporation
	5	* Written by: Martin K. Petersen <martin.petersen@oracle.com>
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License version
	9	* 2 as published by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope that it will be useful, but
	12	* WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; see the file COPYING. If not, write to
	18	* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
	19	* USA.
	20	*
	21	*/
	22
	23	#include <linux/blkdev.h>
	24	#include <linux/mempool.h>
	25	#include <linux/bio.h>
	26	#include <linux/scatterlist.h>
d5decd3b	27	#include <linux/export.h>
5a0e3ad6	28	#include <linux/slab.h>
7ba1ba12 MP	29
	30	#include "blk.h"
	31
	32	static struct kmem_cache *integrity_cachep;
	33
a63a5cf8 MS	34	static const char *bi_unsupported_name = "unsupported";
a63a5cf8 MS	35
7ba1ba12 MP	36	/**
7ba1ba12 MP	37	* blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
13f05c8d MP	38	* @q: request queue
13f05c8d MP	39	* @bio: bio with integrity metadata attached
7ba1ba12 MP	40	*
7ba1ba12 MP	41	* Description: Returns the number of elements required in a
13f05c8d	42	* scatterlist corresponding to the integrity metadata in a bio.
7ba1ba12	43	*/
13f05c8d	44	int blk_rq_count_integrity_sg(struct request_queue q, struct bio bio)
7ba1ba12	45	{
13f05c8d MP	46	struct bio_vec iv, ivprv = NULL;
	47	unsigned int segments = 0;
	48	unsigned int seg_size = 0;
	49	unsigned int i = 0;
7ba1ba12	50
13f05c8d	51	bio_for_each_integrity_vec(iv, bio, i) {
7ba1ba12	52
13f05c8d MP	53	if (ivprv) {
	54	if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
	55	goto new_segment;
	56
	57	if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
	58	goto new_segment;
	59
	60	if (seg_size + iv->bv_len > queue_max_segment_size(q))
	61	goto new_segment;
7ba1ba12	62
13f05c8d MP	63	seg_size += iv->bv_len;
	64	} else {
	65	new_segment:
7ba1ba12	66	segments++;
13f05c8d MP	67	seg_size = iv->bv_len;
13f05c8d MP	68	}
7ba1ba12 MP	69
	70	ivprv = iv;
	71	}
	72
	73	return segments;
	74	}
	75	EXPORT_SYMBOL(blk_rq_count_integrity_sg);
	76
	77	/**
	78	* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
13f05c8d MP	79	* @q: request queue
13f05c8d MP	80	* @bio: bio with integrity metadata attached
7ba1ba12 MP	81	* @sglist: target scatterlist
	82	*
	83	* Description: Map the integrity vectors in request into a
	84	* scatterlist. The scatterlist must be big enough to hold all
	85	* elements. I.e. sized using blk_rq_count_integrity_sg().
	86	*/
13f05c8d MP	87	int blk_rq_map_integrity_sg(struct request_queue q, struct bio bio,
13f05c8d MP	88	struct scatterlist *sglist)
7ba1ba12	89	{
13f05c8d MP	90	struct bio_vec iv, ivprv = NULL;
	91	struct scatterlist *sg = NULL;
	92	unsigned int segments = 0;
	93	unsigned int i = 0;
7ba1ba12	94
13f05c8d	95	bio_for_each_integrity_vec(iv, bio, i) {
7ba1ba12 MP	96
	97	if (ivprv) {
	98	if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
	99	goto new_segment;
	100
13f05c8d MP	101	if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
	102	goto new_segment;
	103
	104	if (sg->length + iv->bv_len > queue_max_segment_size(q))
	105	goto new_segment;
	106
7ba1ba12 MP	107	sg->length += iv->bv_len;
	108	} else {
	109	new_segment:
	110	if (!sg)
	111	sg = sglist;
	112	else {
c8164d89	113	sg_unmark_end(sg);
7ba1ba12 MP	114	sg = sg_next(sg);
	115	}
	116
	117	sg_set_page(sg, iv->bv_page, iv->bv_len, iv->bv_offset);
	118	segments++;
	119	}
	120
	121	ivprv = iv;
	122	}
	123
	124	if (sg)
	125	sg_mark_end(sg);
	126
	127	return segments;
	128	}
	129	EXPORT_SYMBOL(blk_rq_map_integrity_sg);
	130
	131	/**
ad7fce93 MP	132	* blk_integrity_compare - Compare integrity profile of two disks
	133	* @gd1: Disk to compare
	134	* @gd2: Disk to compare
7ba1ba12 MP	135	*
	136	* Description: Meta-devices like DM and MD need to verify that all
	137	* sub-devices use the same integrity format before advertising to
	138	* upper layers that they can send/receive integrity metadata. This
ad7fce93	139	* function can be used to check whether two gendisk devices have
7ba1ba12 MP	140	* compatible integrity formats.
7ba1ba12 MP	141	*/
ad7fce93	142	int blk_integrity_compare(struct gendisk gd1, struct gendisk gd2)
7ba1ba12	143	{
ad7fce93 MP	144	struct blk_integrity *b1 = gd1->integrity;
ad7fce93 MP	145	struct blk_integrity *b2 = gd2->integrity;
7ba1ba12	146
ad7fce93 MP	147	if (!b1 && !b2)
ad7fce93 MP	148	return 0;
7ba1ba12 MP	149
7ba1ba12 MP	150	if (!b1 \|\| !b2)
ad7fce93	151	return -1;
7ba1ba12 MP	152
	153	if (b1->sector_size != b2->sector_size) {
	154	printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
ad7fce93	155	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	156	b1->sector_size, b2->sector_size);
	157	return -1;
	158	}
	159
	160	if (b1->tuple_size != b2->tuple_size) {
	161	printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
ad7fce93	162	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	163	b1->tuple_size, b2->tuple_size);
	164	return -1;
	165	}
	166
	167	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
	168	printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
ad7fce93	169	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	170	b1->tag_size, b2->tag_size);
	171	return -1;
	172	}
	173
	174	if (strcmp(b1->name, b2->name)) {
	175	printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
ad7fce93	176	gd1->disk_name, gd2->disk_name,
7ba1ba12 MP	177	b1->name, b2->name);
	178	return -1;
	179	}
	180
	181	return 0;
	182	}
	183	EXPORT_SYMBOL(blk_integrity_compare);
	184
13f05c8d MP	185	int blk_integrity_merge_rq(struct request_queue q, struct request req,
	186	struct request *next)
	187	{
	188	if (blk_integrity_rq(req) != blk_integrity_rq(next))
	189	return -1;
	190
	191	if (req->nr_integrity_segments + next->nr_integrity_segments >
	192	q->limits.max_integrity_segments)
	193	return -1;
	194
	195	return 0;
	196	}
	197	EXPORT_SYMBOL(blk_integrity_merge_rq);
	198
	199	int blk_integrity_merge_bio(struct request_queue q, struct request req,
	200	struct bio *bio)
	201	{
	202	int nr_integrity_segs;
	203	struct bio *next = bio->bi_next;
	204
	205	bio->bi_next = NULL;
	206	nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
	207	bio->bi_next = next;
	208
	209	if (req->nr_integrity_segments + nr_integrity_segs >
	210	q->limits.max_integrity_segments)
	211	return -1;
	212
	213	req->nr_integrity_segments += nr_integrity_segs;
	214
	215	return 0;
	216	}
	217	EXPORT_SYMBOL(blk_integrity_merge_bio);
	218
7ba1ba12 MP	219	struct integrity_sysfs_entry {
	220	struct attribute attr;
	221	ssize_t (show)(struct blk_integrity , char *);
	222	ssize_t (store)(struct blk_integrity , const char *, size_t);
	223	};
	224
	225	static ssize_t integrity_attr_show(struct kobject kobj, struct attribute attr,
	226	char *page)
	227	{
	228	struct blk_integrity *bi =
	229	container_of(kobj, struct blk_integrity, kobj);
	230	struct integrity_sysfs_entry *entry =
	231	container_of(attr, struct integrity_sysfs_entry, attr);
	232
	233	return entry->show(bi, page);
	234	}
	235
b984679e JA	236	static ssize_t integrity_attr_store(struct kobject *kobj,
	237	struct attribute attr, const char page,
	238	size_t count)
7ba1ba12 MP	239	{
	240	struct blk_integrity *bi =
	241	container_of(kobj, struct blk_integrity, kobj);
	242	struct integrity_sysfs_entry *entry =
	243	container_of(attr, struct integrity_sysfs_entry, attr);
	244	ssize_t ret = 0;
	245
	246	if (entry->store)
	247	ret = entry->store(bi, page, count);
	248
	249	return ret;
	250	}
	251
	252	static ssize_t integrity_format_show(struct blk_integrity bi, char page)
	253	{
	254	if (bi != NULL && bi->name != NULL)
	255	return sprintf(page, "%s\n", bi->name);
	256	else
	257	return sprintf(page, "none\n");
	258	}
	259
	260	static ssize_t integrity_tag_size_show(struct blk_integrity bi, char page)
	261	{
	262	if (bi != NULL)
	263	return sprintf(page, "%u\n", bi->tag_size);
	264	else
	265	return sprintf(page, "0\n");
	266	}
	267
	268	static ssize_t integrity_read_store(struct blk_integrity *bi,
	269	const char *page, size_t count)
	270	{
	271	char p = (char ) page;
	272	unsigned long val = simple_strtoul(p, &p, 10);
	273
	274	if (val)
b24498d4	275	bi->flags \|= INTEGRITY_FLAG_READ;
7ba1ba12	276	else
b24498d4	277	bi->flags &= ~INTEGRITY_FLAG_READ;
7ba1ba12 MP	278
	279	return count;
	280	}
	281
	282	static ssize_t integrity_read_show(struct blk_integrity bi, char page)
	283	{
b24498d4	284	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 0);
7ba1ba12 MP	285	}
	286
	287	static ssize_t integrity_write_store(struct blk_integrity *bi,
	288	const char *page, size_t count)
	289	{
	290	char p = (char ) page;
	291	unsigned long val = simple_strtoul(p, &p, 10);
	292
	293	if (val)
b24498d4	294	bi->flags \|= INTEGRITY_FLAG_WRITE;
7ba1ba12	295	else
b24498d4	296	bi->flags &= ~INTEGRITY_FLAG_WRITE;
7ba1ba12 MP	297
	298	return count;
	299	}
	300
	301	static ssize_t integrity_write_show(struct blk_integrity bi, char page)
	302	{
b24498d4	303	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 0);
7ba1ba12 MP	304	}
	305
	306	static struct integrity_sysfs_entry integrity_format_entry = {
	307	.attr = { .name = "format", .mode = S_IRUGO },
	308	.show = integrity_format_show,
	309	};
	310
	311	static struct integrity_sysfs_entry integrity_tag_size_entry = {
	312	.attr = { .name = "tag_size", .mode = S_IRUGO },
	313	.show = integrity_tag_size_show,
	314	};
	315
	316	static struct integrity_sysfs_entry integrity_read_entry = {
	317	.attr = { .name = "read_verify", .mode = S_IRUGO \| S_IWUSR },
	318	.show = integrity_read_show,
	319	.store = integrity_read_store,
	320	};
	321
	322	static struct integrity_sysfs_entry integrity_write_entry = {
	323	.attr = { .name = "write_generate", .mode = S_IRUGO \| S_IWUSR },
	324	.show = integrity_write_show,
	325	.store = integrity_write_store,
	326	};
	327
	328	static struct attribute *integrity_attrs[] = {
	329	&integrity_format_entry.attr,
	330	&integrity_tag_size_entry.attr,
	331	&integrity_read_entry.attr,
	332	&integrity_write_entry.attr,
	333	NULL,
	334	};
	335
52cf25d0	336	static const struct sysfs_ops integrity_ops = {
7ba1ba12 MP	337	.show = &integrity_attr_show,
	338	.store = &integrity_attr_store,
	339	};
	340
	341	static int __init blk_dev_integrity_init(void)
	342	{
	343	integrity_cachep = kmem_cache_create("blkdev_integrity",
	344	sizeof(struct blk_integrity),
	345	0, SLAB_PANIC, NULL);
	346	return 0;
	347	}
	348	subsys_initcall(blk_dev_integrity_init);
	349
	350	static void blk_integrity_release(struct kobject *kobj)
	351	{
	352	struct blk_integrity *bi =
	353	container_of(kobj, struct blk_integrity, kobj);
	354
	355	kmem_cache_free(integrity_cachep, bi);
	356	}
	357
	358	static struct kobj_type integrity_ktype = {
	359	.default_attrs = integrity_attrs,
	360	.sysfs_ops = &integrity_ops,
	361	.release = blk_integrity_release,
	362	};
	363
a63a5cf8 MS	364	bool blk_integrity_is_initialized(struct gendisk *disk)
	365	{
	366	struct blk_integrity *bi = blk_get_integrity(disk);
	367
	368	return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
	369	}
	370	EXPORT_SYMBOL(blk_integrity_is_initialized);
	371
7ba1ba12 MP	372	/**
	373	* blk_integrity_register - Register a gendisk as being integrity-capable
	374	* @disk: struct gendisk pointer to make integrity-aware
32231638	375	* @template: optional integrity profile to register
7ba1ba12 MP	376	*
	377	* Description: When a device needs to advertise itself as being able
	378	* to send/receive integrity metadata it must use this function to
	379	* register the capability with the block layer. The template is a
	380	* blk_integrity struct with values appropriate for the underlying
32231638 MP	381	* hardware. If template is NULL the new profile is allocated but
32231638 MP	382	* not filled out. See Documentation/block/data-integrity.txt.
7ba1ba12 MP	383	*/
	384	int blk_integrity_register(struct gendisk disk, struct blk_integrity template)
	385	{
	386	struct blk_integrity *bi;
	387
	388	BUG_ON(disk == NULL);
7ba1ba12 MP	389
7ba1ba12 MP	390	if (disk->integrity == NULL) {
b984679e	391	bi = kmem_cache_alloc(integrity_cachep,
32231638	392	GFP_KERNEL \| __GFP_ZERO);
7ba1ba12 MP	393	if (!bi)
	394	return -1;
	395
	396	if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
ed9e1982 TH	397	&disk_to_dev(disk)->kobj,
ed9e1982 TH	398	"%s", "integrity")) {
7ba1ba12 MP	399	kmem_cache_free(integrity_cachep, bi);
	400	return -1;
	401	}
	402
	403	kobject_uevent(&bi->kobj, KOBJ_ADD);
	404
b24498d4	405	bi->flags \|= INTEGRITY_FLAG_READ \| INTEGRITY_FLAG_WRITE;
e1defc4f	406	bi->sector_size = queue_logical_block_size(disk->queue);
7ba1ba12 MP	407	disk->integrity = bi;
	408	} else
	409	bi = disk->integrity;
	410
	411	/* Use the provided profile as template */
32231638 MP	412	if (template != NULL) {
	413	bi->name = template->name;
	414	bi->generate_fn = template->generate_fn;
	415	bi->verify_fn = template->verify_fn;
	416	bi->tuple_size = template->tuple_size;
	417	bi->set_tag_fn = template->set_tag_fn;
	418	bi->get_tag_fn = template->get_tag_fn;
	419	bi->tag_size = template->tag_size;
	420	} else
a63a5cf8	421	bi->name = bi_unsupported_name;
7ba1ba12	422
7d311cda DW	423	disk->queue->backing_dev_info.capabilities \|= BDI_CAP_STABLE_WRITES;
7d311cda DW	424
7ba1ba12 MP	425	return 0;
	426	}
	427	EXPORT_SYMBOL(blk_integrity_register);
	428
	429	/**
	430	* blk_integrity_unregister - Remove block integrity profile
	431	* @disk: disk whose integrity profile to deallocate
	432	*
	433	* Description: This function frees all memory used by the block
	434	* integrity profile. To be called at device teardown.
	435	*/
	436	void blk_integrity_unregister(struct gendisk *disk)
	437	{
	438	struct blk_integrity *bi;
	439
	440	if (!disk \|\| !disk->integrity)
	441	return;
	442
7d311cda DW	443	disk->queue->backing_dev_info.capabilities &= ~BDI_CAP_STABLE_WRITES;
7d311cda DW	444
7ba1ba12 MP	445	bi = disk->integrity;
	446
	447	kobject_uevent(&bi->kobj, KOBJ_REMOVE);
	448	kobject_del(&bi->kobj);
3839e4b2	449	kobject_put(&bi->kobj);
0c032ab8	450	disk->integrity = NULL;
7ba1ba12 MP	451	}
7ba1ba12 MP	452	EXPORT_SYMBOL(blk_integrity_unregister);