// 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);