1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
/* 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;
/* 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);
blk_status_t blk_crypto_get_keyslot(struct blk_crypto_profile *profile,
const struct blk_crypto_key *key,
struct blk_crypto_keyslot **slot_ptr);
void blk_crypto_put_keyslot(struct blk_crypto_keyslot *slot);
bool __blk_crypto_cfg_supported(struct blk_crypto_profile *profile,
const struct blk_crypto_config *cfg);
int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
const struct blk_crypto_key *key);
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 */
|
