arch/x86/include/asm/crypto/glue_helper.h

   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)(void *ctx, u8 *dst, const u8 *src);
  15 typedef void (*common_glue_cbc_func_t)(void *ctx, u128 *dst, const u128 *src);
  16 typedef void (*common_glue_ctr_func_t)(void *ctx, u128 *dst, const u128 *src,
  17                                        le128 *iv);
  18 typedef 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
  26 struct 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
  36 struct 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
  47 static 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
  71 static inline void glue_fpu_end(bool fpu_enabled)
  72 {
  73         if (fpu_enabled)
  74                 kernel_fpu_end();
  75 }
  76
  77 static 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
  83 static 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
  89 static 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
 102 extern int glue_ecb_req_128bit(const struct common_glue_ctx *gctx,
 103                                struct skcipher_request *req);
 104
 105 extern int glue_cbc_encrypt_req_128bit(const common_glue_func_t fn,
 106                                        struct skcipher_request *req);
 107
 108 extern int glue_cbc_decrypt_req_128bit(const struct common_glue_ctx *gctx,
 109                                        struct skcipher_request *req);
 110
 111 extern int glue_ctr_req_128bit(const struct common_glue_ctx *gctx,
 112                                struct skcipher_request *req);
 113
 114 extern 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);
 118
 119 extern 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 */