155 lines
5.3 KiB
C
155 lines
5.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright 2019 Google LLC
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*/
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#ifndef __LINUX_BLK_CRYPTO_PROFILE_H
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#define __LINUX_BLK_CRYPTO_PROFILE_H
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#include <linux/bio.h>
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#include <linux/blk-crypto.h>
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struct blk_crypto_profile;
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/**
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* struct blk_crypto_ll_ops - functions to control inline encryption hardware
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*
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* Low-level operations for controlling inline encryption hardware. This
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* interface must be implemented by storage drivers that support inline
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* encryption. All functions may sleep, are serialized by profile->lock, and
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* are never called while profile->dev (if set) is runtime-suspended.
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*/
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struct blk_crypto_ll_ops {
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/**
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* @keyslot_program: Program a key into the inline encryption hardware.
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*
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* Program @key into the specified @slot in the inline encryption
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* hardware, overwriting any key that the keyslot may already contain.
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* The keyslot is guaranteed to not be in-use by any I/O.
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*
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* This is required if the device has keyslots. Otherwise (i.e. if the
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* device is a layered device, or if the device is real hardware that
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* simply doesn't have the concept of keyslots) it is never called.
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*
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* Must return 0 on success, or -errno on failure.
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*/
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int (*keyslot_program)(struct blk_crypto_profile *profile,
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const struct blk_crypto_key *key,
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unsigned int slot);
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/**
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* @keyslot_evict: Evict a key from the inline encryption hardware.
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*
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* If the device has keyslots, this function must evict the key from the
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* specified @slot. The slot will contain @key, but there should be no
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* need for the @key argument to be used as @slot should be sufficient.
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* The keyslot is guaranteed to not be in-use by any I/O.
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*
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* If the device doesn't have keyslots itself, this function must evict
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* @key from any underlying devices. @slot won't be valid in this case.
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*
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* If there are no keyslots and no underlying devices, this function
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* isn't required.
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*
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* Must return 0 on success, or -errno on failure.
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*/
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int (*keyslot_evict)(struct blk_crypto_profile *profile,
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const struct blk_crypto_key *key,
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unsigned int slot);
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};
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/**
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* struct blk_crypto_profile - inline encryption profile for a device
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*
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* This struct contains a storage device's inline encryption capabilities (e.g.
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* the supported crypto algorithms), driver-provided functions to control the
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* inline encryption hardware (e.g. programming and evicting keys), and optional
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* device-independent keyslot management data.
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*/
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struct blk_crypto_profile {
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/* public: Drivers must initialize the following fields. */
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/**
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* @ll_ops: Driver-provided functions to control the inline encryption
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* hardware, e.g. program and evict keys.
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*/
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struct blk_crypto_ll_ops ll_ops;
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/**
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* @max_dun_bytes_supported: The maximum number of bytes supported for
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* specifying the data unit number (DUN). Specifically, the range of
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* supported DUNs is 0 through (1 << (8 * max_dun_bytes_supported)) - 1.
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*/
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unsigned int max_dun_bytes_supported;
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/**
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* @modes_supported: Array of bitmasks that specifies whether each
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* combination of crypto mode and data unit size is supported.
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* Specifically, the i'th bit of modes_supported[crypto_mode] is set if
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* crypto_mode can be used with a data unit size of (1 << i). Note that
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* only data unit sizes that are powers of 2 can be supported.
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*/
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unsigned int modes_supported[BLK_ENCRYPTION_MODE_MAX];
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/**
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* @dev: An optional device for runtime power management. If the driver
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* provides this device, it will be runtime-resumed before any function
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* in @ll_ops is called and will remain resumed during the call.
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*/
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struct device *dev;
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/* private: The following fields shouldn't be accessed by drivers. */
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/* Number of keyslots, or 0 if not applicable */
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unsigned int num_slots;
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/*
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* Serializes all calls to functions in @ll_ops as well as all changes
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* to @slot_hashtable. This can also be taken in read mode to look up
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* keyslots while ensuring that they can't be changed concurrently.
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*/
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struct rw_semaphore lock;
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/* List of idle slots, with least recently used slot at front */
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wait_queue_head_t idle_slots_wait_queue;
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struct list_head idle_slots;
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spinlock_t idle_slots_lock;
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/*
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* Hash table which maps struct *blk_crypto_key to keyslots, so that we
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* can find a key's keyslot in O(1) time rather than O(num_slots).
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* Protected by 'lock'.
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*/
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struct hlist_head *slot_hashtable;
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unsigned int log_slot_ht_size;
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/* Per-keyslot data */
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struct blk_crypto_keyslot *slots;
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};
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int blk_crypto_profile_init(struct blk_crypto_profile *profile,
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unsigned int num_slots);
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int devm_blk_crypto_profile_init(struct device *dev,
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struct blk_crypto_profile *profile,
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unsigned int num_slots);
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unsigned int blk_crypto_keyslot_index(struct blk_crypto_keyslot *slot);
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void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile);
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void blk_crypto_profile_destroy(struct blk_crypto_profile *profile);
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void blk_crypto_intersect_capabilities(struct blk_crypto_profile *parent,
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const struct blk_crypto_profile *child);
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bool blk_crypto_has_capabilities(const struct blk_crypto_profile *target,
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const struct blk_crypto_profile *reference);
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void blk_crypto_update_capabilities(struct blk_crypto_profile *dst,
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const struct blk_crypto_profile *src);
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#endif /* __LINUX_BLK_CRYPTO_PROFILE_H */
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