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/i387.h>
11#include <crypto/b128ops.h>
12
13typedef void (*common_glue_func_t)(void *ctx, u8 *dst, const u8 *src);
14typedef void (*common_glue_cbc_func_t)(void *ctx, u128 *dst, const u128 *src);
15typedef void (*common_glue_ctr_func_t)(void *ctx, u128 *dst, const u128 *src,
16				       le128 *iv);
17typedef 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
25struct 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
35struct 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
46static 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
72static inline void glue_fpu_end(bool fpu_enabled)
73{
74	if (fpu_enabled)
75		kernel_fpu_end();
76}
77
78static 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
84static 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
90static 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
103static 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
113extern 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
118extern 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
124extern 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
130extern 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
135extern 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
142extern 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