1 /*
2 * Shared glue code for 128bit block ciphers
3 */
4
5 #ifndef _CRYPTO_GLUE_HELPER_H
6 #define _CRYPTO_GLUE_HELPER_H
7
8 #include <linux/kernel.h>
9 #include <linux/crypto.h>
10 #include <asm/fpu/api.h>
11 #include <crypto/b128ops.h>
12
13 typedef void (*common_glue_func_t)(void *ctx, u8 *dst, const u8 *src);
14 typedef void (*common_glue_cbc_func_t)(void *ctx, u128 *dst, const u128 *src);
15 typedef void (*common_glue_ctr_func_t)(void *ctx, u128 *dst, const u128 *src,
16 le128 *iv);
17 typedef void (*common_glue_xts_func_t)(void *ctx, u128 *dst, const u128 *src,
18 le128 *iv);
19
20 #define GLUE_FUNC_CAST(fn) ((common_glue_func_t)(fn))
21 #define GLUE_CBC_FUNC_CAST(fn) ((common_glue_cbc_func_t)(fn))
22 #define GLUE_CTR_FUNC_CAST(fn) ((common_glue_ctr_func_t)(fn))
23 #define GLUE_XTS_FUNC_CAST(fn) ((common_glue_xts_func_t)(fn))
24
25 struct common_glue_func_entry {
26 unsigned int num_blocks; /* number of blocks that @fn will process */
27 union {
28 common_glue_func_t ecb;
29 common_glue_cbc_func_t cbc;
30 common_glue_ctr_func_t ctr;
31 common_glue_xts_func_t xts;
32 } fn_u;
33 };
34
35 struct common_glue_ctx {
36 unsigned int num_funcs;
37 int fpu_blocks_limit; /* -1 means fpu not needed at all */
38
39 /*
40 * First funcs entry must have largest num_blocks and last funcs entry
41 * must have num_blocks == 1!
42 */
43 struct common_glue_func_entry funcs[];
44 };
45
glue_fpu_begin(unsigned int bsize,int fpu_blocks_limit,struct blkcipher_desc * desc,bool fpu_enabled,unsigned int nbytes)46 static inline bool glue_fpu_begin(unsigned int bsize, int fpu_blocks_limit,
47 struct blkcipher_desc *desc,
48 bool fpu_enabled, unsigned int nbytes)
49 {
50 if (likely(fpu_blocks_limit < 0))
51 return false;
52
53 if (fpu_enabled)
54 return true;
55
56 /*
57 * Vector-registers are only used when chunk to be processed is large
58 * enough, so do not enable FPU until it is necessary.
59 */
60 if (nbytes < bsize * (unsigned int)fpu_blocks_limit)
61 return false;
62
63 if (desc) {
64 /* prevent sleeping if FPU is in use */
65 desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
66 }
67
68 kernel_fpu_begin();
69 return true;
70 }
71
glue_fpu_end(bool fpu_enabled)72 static inline void glue_fpu_end(bool fpu_enabled)
73 {
74 if (fpu_enabled)
75 kernel_fpu_end();
76 }
77
le128_to_be128(be128 * dst,const le128 * src)78 static inline void le128_to_be128(be128 *dst, const le128 *src)
79 {
80 dst->a = cpu_to_be64(le64_to_cpu(src->a));
81 dst->b = cpu_to_be64(le64_to_cpu(src->b));
82 }
83
be128_to_le128(le128 * dst,const be128 * src)84 static inline void be128_to_le128(le128 *dst, const be128 *src)
85 {
86 dst->a = cpu_to_le64(be64_to_cpu(src->a));
87 dst->b = cpu_to_le64(be64_to_cpu(src->b));
88 }
89
le128_inc(le128 * i)90 static inline void le128_inc(le128 *i)
91 {
92 u64 a = le64_to_cpu(i->a);
93 u64 b = le64_to_cpu(i->b);
94
95 b++;
96 if (!b)
97 a++;
98
99 i->a = cpu_to_le64(a);
100 i->b = cpu_to_le64(b);
101 }
102
le128_gf128mul_x_ble(le128 * dst,const le128 * src)103 static inline void le128_gf128mul_x_ble(le128 *dst, const le128 *src)
104 {
105 u64 a = le64_to_cpu(src->a);
106 u64 b = le64_to_cpu(src->b);
107 u64 _tt = ((s64)a >> 63) & 0x87;
108
109 dst->a = cpu_to_le64((a << 1) ^ (b >> 63));
110 dst->b = cpu_to_le64((b << 1) ^ _tt);
111 }
112
113 extern int glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
114 struct blkcipher_desc *desc,
115 struct scatterlist *dst,
116 struct scatterlist *src, unsigned int nbytes);
117
118 extern int glue_cbc_encrypt_128bit(const common_glue_func_t fn,
119 struct blkcipher_desc *desc,
120 struct scatterlist *dst,
121 struct scatterlist *src,
122 unsigned int nbytes);
123
124 extern int glue_cbc_decrypt_128bit(const struct common_glue_ctx *gctx,
125 struct blkcipher_desc *desc,
126 struct scatterlist *dst,
127 struct scatterlist *src,
128 unsigned int nbytes);
129
130 extern int glue_ctr_crypt_128bit(const struct common_glue_ctx *gctx,
131 struct blkcipher_desc *desc,
132 struct scatterlist *dst,
133 struct scatterlist *src, unsigned int nbytes);
134
135 extern int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
136 struct blkcipher_desc *desc,
137 struct scatterlist *dst,
138 struct scatterlist *src, unsigned int nbytes,
139 common_glue_func_t tweak_fn, void *tweak_ctx,
140 void *crypt_ctx);
141
142 extern void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src,
143 le128 *iv, common_glue_func_t fn);
144
145 #endif /* _CRYPTO_GLUE_HELPER_H */
146