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