last zone of the device which may be smaller.
+What: /sys/block/<disk>/queue/crypto/
+Date: February 2022
+Contact: linux-block@vger.kernel.org
+Description:
+ The presence of this subdirectory of /sys/block/<disk>/queue/
+ indicates that the device supports inline encryption. This
+ subdirectory contains files which describe the inline encryption
+ capabilities of the device. For more information about inline
+ encryption, refer to Documentation/block/inline-encryption.rst.
+
+
+What: /sys/block/<disk>/queue/crypto/max_dun_bits
+Date: February 2022
+Contact: linux-block@vger.kernel.org
+Description:
+ [RO] This file shows the maximum length, in bits, of data unit
+ numbers accepted by the device in inline encryption requests.
+
+
+What: /sys/block/<disk>/queue/crypto/modes/<mode>
+Date: February 2022
+Contact: linux-block@vger.kernel.org
+Description:
+ [RO] For each crypto mode (i.e., encryption/decryption
+ algorithm) the device supports with inline encryption, a file
+ will exist at this location. It will contain a hexadecimal
+ number that is a bitmask of the supported data unit sizes, in
+ bytes, for that crypto mode.
+
+ Currently, the crypto modes that may be supported are:
+
+ * AES-256-XTS
+ * AES-128-CBC-ESSIV
+ * Adiantum
+
+ For example, if a device supports AES-256-XTS inline encryption
+ with data unit sizes of 512 and 4096 bytes, the file
+ /sys/block/<disk>/queue/crypto/modes/AES-256-XTS will exist and
+ will contain "0x1200".
+
+
+What: /sys/block/<disk>/queue/crypto/num_keyslots
+Date: February 2022
+Contact: linux-block@vger.kernel.org
+Description:
+ [RO] This file shows the number of keyslots the device has for
+ use with inline encryption.
+
+
What: /sys/block/<disk>/queue/dax
Date: June 2016
Contact: linux-block@vger.kernel.org
--- /dev/null
+// 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);
projects / kernel.git / commitdiff