1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright 2019 Google LLC 4 */ 5 6 #ifndef __LINUX_BLK_CRYPTO_PROFILE_H 7 #define __LINUX_BLK_CRYPTO_PROFILE_H 8 9 #include <linux/bio.h> 10 #include <linux/blk-crypto.h> 11 12 struct blk_crypto_profile; 13 14 /** 15 * struct blk_crypto_ll_ops - functions to control inline encryption hardware 16 * 17 * Low-level operations for controlling inline encryption hardware. This 18 * interface must be implemented by storage drivers that support inline 19 * encryption. All functions may sleep, are serialized by profile->lock, and 20 * are never called while profile->dev (if set) is runtime-suspended. 21 */ 22 struct blk_crypto_ll_ops { 23 24 /** 25 * @keyslot_program: Program a key into the inline encryption hardware. 26 * 27 * Program @key into the specified @slot in the inline encryption 28 * hardware, overwriting any key that the keyslot may already contain. 29 * The keyslot is guaranteed to not be in-use by any I/O. 30 * 31 * This is required if the device has keyslots. Otherwise (i.e. if the 32 * device is a layered device, or if the device is real hardware that 33 * simply doesn't have the concept of keyslots) it is never called. 34 * 35 * Must return 0 on success, or -errno on failure. 36 */ 37 int (*keyslot_program)(struct blk_crypto_profile *profile, 38 const struct blk_crypto_key *key, 39 unsigned int slot); 40 41 /** 42 * @keyslot_evict: Evict a key from the inline encryption hardware. 43 * 44 * If the device has keyslots, this function must evict the key from the 45 * specified @slot. The slot will contain @key, but there should be no 46 * need for the @key argument to be used as @slot should be sufficient. 47 * The keyslot is guaranteed to not be in-use by any I/O. 48 * 49 * If the device doesn't have keyslots itself, this function must evict 50 * @key from any underlying devices. @slot won't be valid in this case. 51 * 52 * If there are no keyslots and no underlying devices, this function 53 * isn't required. 54 * 55 * Must return 0 on success, or -errno on failure. 56 */ 57 int (*keyslot_evict)(struct blk_crypto_profile *profile, 58 const struct blk_crypto_key *key, 59 unsigned int slot); 60 }; 61 62 /** 63 * struct blk_crypto_profile - inline encryption profile for a device 64 * 65 * This struct contains a storage device's inline encryption capabilities (e.g. 66 * the supported crypto algorithms), driver-provided functions to control the 67 * inline encryption hardware (e.g. programming and evicting keys), and optional 68 * device-independent keyslot management data. 69 */ 70 struct blk_crypto_profile { 71 72 /* public: Drivers must initialize the following fields. */ 73 74 /** 75 * @ll_ops: Driver-provided functions to control the inline encryption 76 * hardware, e.g. program and evict keys. 77 */ 78 struct blk_crypto_ll_ops ll_ops; 79 80 /** 81 * @max_dun_bytes_supported: The maximum number of bytes supported for 82 * specifying the data unit number (DUN). Specifically, the range of 83 * supported DUNs is 0 through (1 << (8 * max_dun_bytes_supported)) - 1. 84 */ 85 unsigned int max_dun_bytes_supported; 86 87 /** 88 * @modes_supported: Array of bitmasks that specifies whether each 89 * combination of crypto mode and data unit size is supported. 90 * Specifically, the i'th bit of modes_supported[crypto_mode] is set if 91 * crypto_mode can be used with a data unit size of (1 << i). Note that 92 * only data unit sizes that are powers of 2 can be supported. 93 */ 94 unsigned int modes_supported[BLK_ENCRYPTION_MODE_MAX]; 95 96 /** 97 * @dev: An optional device for runtime power management. If the driver 98 * provides this device, it will be runtime-resumed before any function 99 * in @ll_ops is called and will remain resumed during the call. 100 */ 101 struct device *dev; 102 103 /* private: The following fields shouldn't be accessed by drivers. */ 104 105 /* Number of keyslots, or 0 if not applicable */ 106 unsigned int num_slots; 107 108 /* 109 * Serializes all calls to functions in @ll_ops as well as all changes 110 * to @slot_hashtable. This can also be taken in read mode to look up 111 * keyslots while ensuring that they can't be changed concurrently. 112 */ 113 struct rw_semaphore lock; 114 struct lock_class_key lockdep_key; 115 116 /* List of idle slots, with least recently used slot at front */ 117 wait_queue_head_t idle_slots_wait_queue; 118 struct list_head idle_slots; 119 spinlock_t idle_slots_lock; 120 121 /* 122 * Hash table which maps struct *blk_crypto_key to keyslots, so that we 123 * can find a key's keyslot in O(1) time rather than O(num_slots). 124 * Protected by 'lock'. 125 */ 126 struct hlist_head *slot_hashtable; 127 unsigned int log_slot_ht_size; 128 129 /* Per-keyslot data */ 130 struct blk_crypto_keyslot *slots; 131 }; 132 133 int blk_crypto_profile_init(struct blk_crypto_profile *profile, 134 unsigned int num_slots); 135 136 int devm_blk_crypto_profile_init(struct device *dev, 137 struct blk_crypto_profile *profile, 138 unsigned int num_slots); 139 140 unsigned int blk_crypto_keyslot_index(struct blk_crypto_keyslot *slot); 141 142 void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile); 143 144 void blk_crypto_profile_destroy(struct blk_crypto_profile *profile); 145 146 void blk_crypto_intersect_capabilities(struct blk_crypto_profile *parent, 147 const struct blk_crypto_profile *child); 148 149 bool blk_crypto_has_capabilities(const struct blk_crypto_profile *target, 150 const struct blk_crypto_profile *reference); 151 152 void blk_crypto_update_capabilities(struct blk_crypto_profile *dst, 153 const struct blk_crypto_profile *src); 154 155 #endif /* __LINUX_BLK_CRYPTO_PROFILE_H */ 156