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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Shared glue code for 128bit block ciphers
4 */
5
6#ifndef _CRYPTO_GLUE_HELPER_H
7#define _CRYPTO_GLUE_HELPER_H
8
9#include <crypto/internal/skcipher.h>
10#include <linux/kernel.h>
11#include <asm/fpu/api.h>
12#include <crypto/b128ops.h>
13
14typedef void (*common_glue_func_t)(void *ctx, u8 *dst, const u8 *src);
15typedef void (*common_glue_cbc_func_t)(void *ctx, u128 *dst, const u128 *src);
16typedef void (*common_glue_ctr_func_t)(void *ctx, u128 *dst, const u128 *src,
17 le128 *iv);
18typedef void (*common_glue_xts_func_t)(void *ctx, u128 *dst, const u128 *src,
19 le128 *iv);
20
21#define GLUE_FUNC_CAST(fn) ((common_glue_func_t)(fn))
22#define GLUE_CBC_FUNC_CAST(fn) ((common_glue_cbc_func_t)(fn))
23#define GLUE_CTR_FUNC_CAST(fn) ((common_glue_ctr_func_t)(fn))
24#define GLUE_XTS_FUNC_CAST(fn) ((common_glue_xts_func_t)(fn))
25
26struct common_glue_func_entry {
27 unsigned int num_blocks; /* number of blocks that @fn will process */
28 union {
29 common_glue_func_t ecb;
30 common_glue_cbc_func_t cbc;
31 common_glue_ctr_func_t ctr;
32 common_glue_xts_func_t xts;
33 } fn_u;
34};
35
36struct common_glue_ctx {
37 unsigned int num_funcs;
38 int fpu_blocks_limit; /* -1 means fpu not needed at all */
39
40 /*
41 * First funcs entry must have largest num_blocks and last funcs entry
42 * must have num_blocks == 1!
43 */
44 struct common_glue_func_entry funcs[];
45};
46
47static inline bool glue_fpu_begin(unsigned int bsize, int fpu_blocks_limit,
48 struct skcipher_walk *walk,
49 bool fpu_enabled, unsigned int nbytes)
50{
51 if (likely(fpu_blocks_limit < 0))
52 return false;
53
54 if (fpu_enabled)
55 return true;
56
57 /*
58 * Vector-registers are only used when chunk to be processed is large
59 * enough, so do not enable FPU until it is necessary.
60 */
61 if (nbytes < bsize * (unsigned int)fpu_blocks_limit)
62 return false;
63
64 /* prevent sleeping if FPU is in use */
65 skcipher_walk_atomise(walk);
66
67 kernel_fpu_begin();
68 return true;
69}
70
71static inline void glue_fpu_end(bool fpu_enabled)
72{
73 if (fpu_enabled)
74 kernel_fpu_end();
75}
76
77static inline void le128_to_be128(be128 *dst, const le128 *src)
78{
79 dst->a = cpu_to_be64(le64_to_cpu(src->a));
80 dst->b = cpu_to_be64(le64_to_cpu(src->b));
81}
82
83static inline void be128_to_le128(le128 *dst, const be128 *src)
84{
85 dst->a = cpu_to_le64(be64_to_cpu(src->a));
86 dst->b = cpu_to_le64(be64_to_cpu(src->b));
87}
88
89static inline void le128_inc(le128 *i)
90{
91 u64 a = le64_to_cpu(i->a);
92 u64 b = le64_to_cpu(i->b);
93
94 b++;
95 if (!b)
96 a++;
97
98 i->a = cpu_to_le64(a);
99 i->b = cpu_to_le64(b);
100}
101
102extern int glue_ecb_req_128bit(const struct common_glue_ctx *gctx,
103 struct skcipher_request *req);
104
105extern int glue_cbc_encrypt_req_128bit(const common_glue_func_t fn,
106 struct skcipher_request *req);
107
108extern int glue_cbc_decrypt_req_128bit(const struct common_glue_ctx *gctx,
109 struct skcipher_request *req);
110
111extern int glue_ctr_req_128bit(const struct common_glue_ctx *gctx,
112 struct skcipher_request *req);
113
114extern int glue_xts_req_128bit(const struct common_glue_ctx *gctx,
115 struct skcipher_request *req,
116 common_glue_func_t tweak_fn, void *tweak_ctx,
117 void *crypt_ctx, bool decrypt);
118
119extern void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src,
120 le128 *iv, common_glue_func_t fn);
121
122#endif /* _CRYPTO_GLUE_HELPER_H */