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