diff options
Diffstat (limited to 'include/linux/blk-crypto-profile.h')
| -rw-r--r-- | include/linux/blk-crypto-profile.h | 164 |
1 files changed, 105 insertions, 59 deletions
diff --git a/include/linux/blk-crypto-profile.h b/include/linux/blk-crypto-profile.h index a27605e2f826..bbab65bd5428 100644 --- a/include/linux/blk-crypto-profile.h +++ b/include/linux/blk-crypto-profile.h @@ -3,67 +3,113 @@ * Copyright 2019 Google LLC */ -#ifndef __LINUX_KEYSLOT_MANAGER_H -#define __LINUX_KEYSLOT_MANAGER_H +#ifndef __LINUX_BLK_CRYPTO_PROFILE_H +#define __LINUX_BLK_CRYPTO_PROFILE_H #include <linux/bio.h> #include <linux/blk-crypto.h> -struct blk_keyslot_manager; +struct blk_crypto_profile; /** - * struct blk_ksm_ll_ops - functions to manage keyslots in hardware - * @keyslot_program: Program the specified key into the specified slot in the - * inline encryption hardware. - * @keyslot_evict: Evict key from the specified keyslot in the hardware. - * The key is provided so that e.g. dm layers can evict - * keys from the devices that they map over. - * Returns 0 on success, -errno otherwise. + * struct blk_crypto_ll_ops - functions to control inline encryption hardware * - * This structure should be provided by storage device drivers when they set up - * a keyslot manager - this structure holds the function ptrs that the keyslot - * manager will use to manipulate keyslots in the 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_ksm_ll_ops { - int (*keyslot_program)(struct blk_keyslot_manager *ksm, +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); - int (*keyslot_evict)(struct blk_keyslot_manager *ksm, + + /** + * @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_keyslot_manager { - /* - * The struct blk_ksm_ll_ops that this keyslot manager will use - * to perform operations like programming and evicting keys on the - * device +/** + * 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_ksm_ll_ops ksm_ll_ops; + struct blk_crypto_ll_ops ll_ops; - /* - * The maximum number of bytes supported for specifying the data unit - * number. + /** + * @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; - /* - * Array of size BLK_ENCRYPTION_MODE_MAX of bitmasks that represents - * whether a crypto mode and data unit size are supported. The i'th - * bit of crypto_mode_supported[crypto_mode] is set iff a data unit - * size of (1 << i) is supported. We only support data unit sizes - * that are powers of 2. + /** + * @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 crypto_modes_supported[BLK_ENCRYPTION_MODE_MAX]; + unsigned int modes_supported[BLK_ENCRYPTION_MODE_MAX]; - /* Device for runtime power management (NULL if none) */ + /** + * @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; - /* Here onwards are *private* fields for internal keyslot manager use */ + /* private: The following fields shouldn't be accessed by drivers. */ + /* Number of keyslots, or 0 if not applicable */ unsigned int num_slots; - /* Protects programming and evicting keys from the device */ + /* + * 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; /* List of idle slots, with least recently used slot at front */ @@ -80,41 +126,41 @@ struct blk_keyslot_manager { unsigned int log_slot_ht_size; /* Per-keyslot data */ - struct blk_ksm_keyslot *slots; + struct blk_crypto_keyslot *slots; }; -int blk_ksm_init(struct blk_keyslot_manager *ksm, unsigned int num_slots); - -int devm_blk_ksm_init(struct device *dev, struct blk_keyslot_manager *ksm, - unsigned int num_slots); +int blk_crypto_profile_init(struct blk_crypto_profile *profile, + unsigned int num_slots); -blk_status_t blk_ksm_get_slot_for_key(struct blk_keyslot_manager *ksm, - const struct blk_crypto_key *key, - struct blk_ksm_keyslot **slot_ptr); +int devm_blk_crypto_profile_init(struct device *dev, + struct blk_crypto_profile *profile, + unsigned int num_slots); -unsigned int blk_ksm_get_slot_idx(struct blk_ksm_keyslot *slot); +unsigned int blk_crypto_keyslot_index(struct blk_crypto_keyslot *slot); -void blk_ksm_put_slot(struct blk_ksm_keyslot *slot); +blk_status_t blk_crypto_get_keyslot(struct blk_crypto_profile *profile, + const struct blk_crypto_key *key, + struct blk_crypto_keyslot **slot_ptr); -bool blk_ksm_crypto_cfg_supported(struct blk_keyslot_manager *ksm, - const struct blk_crypto_config *cfg); +void blk_crypto_put_keyslot(struct blk_crypto_keyslot *slot); -int blk_ksm_evict_key(struct blk_keyslot_manager *ksm, - const struct blk_crypto_key *key); +bool __blk_crypto_cfg_supported(struct blk_crypto_profile *profile, + const struct blk_crypto_config *cfg); -void blk_ksm_reprogram_all_keys(struct blk_keyslot_manager *ksm); +int __blk_crypto_evict_key(struct blk_crypto_profile *profile, + const struct blk_crypto_key *key); -void blk_ksm_destroy(struct blk_keyslot_manager *ksm); +void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile); -void blk_ksm_intersect_modes(struct blk_keyslot_manager *parent, - const struct blk_keyslot_manager *child); +void blk_crypto_profile_destroy(struct blk_crypto_profile *profile); -void blk_ksm_init_passthrough(struct blk_keyslot_manager *ksm); +void blk_crypto_intersect_capabilities(struct blk_crypto_profile *parent, + const struct blk_crypto_profile *child); -bool blk_ksm_is_superset(struct blk_keyslot_manager *ksm_superset, - struct blk_keyslot_manager *ksm_subset); +bool blk_crypto_has_capabilities(const struct blk_crypto_profile *target, + const struct blk_crypto_profile *reference); -void blk_ksm_update_capabilities(struct blk_keyslot_manager *target_ksm, - struct blk_keyslot_manager *reference_ksm); +void blk_crypto_update_capabilities(struct blk_crypto_profile *dst, + const struct blk_crypto_profile *src); -#endif /* __LINUX_KEYSLOT_MANAGER_H */ +#endif /* __LINUX_BLK_CRYPTO_PROFILE_H */ |