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

   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
  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
  72 static inline void glue_fpu_end(bool fpu_enabled)
  73 {
  74         if (fpu_enabled)
  75                 kernel_fpu_end();
  76 }
  77
  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
  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
  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
 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 */