blob: fd93bd2f33b7580f596d5b00f9006dfb2bead608 [file] [log] [blame]
// 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 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 request_queue *q)
{
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, &q->kobj,
"crypto");
if (err) {
kobject_put(&obj->kobj);
return err;
}
q->crypto_kobject = &obj->kobj;
return 0;
}
void blk_crypto_sysfs_unregister(struct request_queue *q)
{
kobject_put(q->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);