summaryrefslogtreecommitdiff
path: root/block/blk-crypto-sysfs.c
blob: a304434489bacf05550c5c2f9c6f0f27b335323d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2021 Google LLC
 *
 * sysfs support for blk-crypto.  This file contains the code which exports the
 * crypto capabilities of devices via /sys/block/$disk/queue/crypto/.
 */

#include <linux/blk-crypto-profile.h>

#include "blk-crypto-internal.h"

struct blk_crypto_kobj {
	struct kobject kobj;
	struct blk_crypto_profile *profile;
};

struct blk_crypto_attr {
	struct attribute attr;
	ssize_t (*show)(struct blk_crypto_profile *profile,
			struct blk_crypto_attr *attr, char *page);
};

static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
{
	return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
}

static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
{
	return container_of(attr, struct blk_crypto_attr, attr);
}

static ssize_t max_dun_bits_show(struct blk_crypto_profile *profile,
				 struct blk_crypto_attr *attr, char *page)
{
	return sysfs_emit(page, "%u\n", 8 * profile->max_dun_bytes_supported);
}

static ssize_t num_keyslots_show(struct blk_crypto_profile *profile,
				 struct blk_crypto_attr *attr, char *page)
{
	return sysfs_emit(page, "%u\n", profile->num_slots);
}

#define BLK_CRYPTO_RO_ATTR(_name) \
	static struct blk_crypto_attr _name##_attr = __ATTR_RO(_name)

BLK_CRYPTO_RO_ATTR(max_dun_bits);
BLK_CRYPTO_RO_ATTR(num_keyslots);

static struct attribute *blk_crypto_attrs[] = {
	&max_dun_bits_attr.attr,
	&num_keyslots_attr.attr,
	NULL,
};

static const struct attribute_group blk_crypto_attr_group = {
	.attrs = blk_crypto_attrs,
};

/*
 * The encryption mode attributes.  To avoid hard-coding the list of encryption
 * modes, these are initialized at boot time by blk_crypto_sysfs_init().
 */
static struct blk_crypto_attr __blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX];
static struct attribute *blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX + 1];

static umode_t blk_crypto_mode_is_visible(struct kobject *kobj,
					  struct attribute *attr, int n)
{
	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
	int mode_num = a - __blk_crypto_mode_attrs;

	if (profile->modes_supported[mode_num])
		return 0444;
	return 0;
}

static ssize_t blk_crypto_mode_show(struct blk_crypto_profile *profile,
				    struct blk_crypto_attr *attr, char *page)
{
	int mode_num = attr - __blk_crypto_mode_attrs;

	return sysfs_emit(page, "0x%x\n", profile->modes_supported[mode_num]);
}

static const struct attribute_group blk_crypto_modes_attr_group = {
	.name = "modes",
	.attrs = blk_crypto_mode_attrs,
	.is_visible = blk_crypto_mode_is_visible,
};

static const struct attribute_group *blk_crypto_attr_groups[] = {
	&blk_crypto_attr_group,
	&blk_crypto_modes_attr_group,
	NULL,
};

static ssize_t blk_crypto_attr_show(struct kobject *kobj,
				    struct attribute *attr, char *page)
{
	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);

	return a->show(profile, a, page);
}

static const struct sysfs_ops blk_crypto_attr_ops = {
	.show = blk_crypto_attr_show,
};

static void blk_crypto_release(struct kobject *kobj)
{
	kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
}

static const struct kobj_type blk_crypto_ktype = {
	.default_groups = blk_crypto_attr_groups,
	.sysfs_ops	= &blk_crypto_attr_ops,
	.release	= blk_crypto_release,
};

/*
 * If the request_queue has a blk_crypto_profile, create the "crypto"
 * subdirectory in sysfs (/sys/block/$disk/queue/crypto/).
 */
int blk_crypto_sysfs_register(struct gendisk *disk)
{
	struct request_queue *q = disk->queue;
	struct blk_crypto_kobj *obj;
	int err;

	if (!q->crypto_profile)
		return 0;

	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
	if (!obj)
		return -ENOMEM;
	obj->profile = q->crypto_profile;

	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype,
				   &disk->queue_kobj, "crypto");
	if (err) {
		kobject_put(&obj->kobj);
		return err;
	}
	q->crypto_kobject = &obj->kobj;
	return 0;
}

void blk_crypto_sysfs_unregister(struct gendisk *disk)
{
	kobject_put(disk->queue->crypto_kobject);
}

static int __init blk_crypto_sysfs_init(void)
{
	int i;

	BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0);
	for (i = 1; i < BLK_ENCRYPTION_MODE_MAX; i++) {
		struct blk_crypto_attr *attr = &__blk_crypto_mode_attrs[i];

		attr->attr.name = blk_crypto_modes[i].name;
		attr->attr.mode = 0444;
		attr->show = blk_crypto_mode_show;
		blk_crypto_mode_attrs[i - 1] = &attr->attr;
	}
	return 0;
}
subsys_initcall(blk_crypto_sysfs_init);