diff options
Diffstat (limited to 'block/blk-crypto-sysfs.c')
| -rw-r--r-- | block/blk-crypto-sysfs.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/block/blk-crypto-sysfs.c b/block/blk-crypto-sysfs.c new file mode 100644 index 000000000..fd93bd2f3 --- /dev/null +++ b/block/blk-crypto-sysfs.c @@ -0,0 +1,172 @@ +// 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); |