arch/mips/net/bpf_jit.h

   1 /*
   2  * Just-In-Time compiler for BPF filters on MIPS
   3  *
   4  * Copyright (c) 2014 Imagination Technologies Ltd.
   5  * Author: Markos Chandras <markos.chandras@imgtec.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; version 2 of the License.
  10  */
  11
  12 #ifndef BPF_JIT_MIPS_OP_H
  13 #define BPF_JIT_MIPS_OP_H
  14
  15 /* Registers used by JIT */
  16 #define MIPS_R_ZERO     0
  17 #define MIPS_R_V0       2
  18 #define MIPS_R_A0       4
  19 #define MIPS_R_A1       5
  20 #define MIPS_R_T4       12
  21 #define MIPS_R_T5       13
  22 #define MIPS_R_T6       14
  23 #define MIPS_R_T7       15
  24 #define MIPS_R_S0       16
  25 #define MIPS_R_S1       17
  26 #define MIPS_R_S2       18
  27 #define MIPS_R_S3       19
  28 #define MIPS_R_S4       20
  29 #define MIPS_R_S5       21
  30 #define MIPS_R_S6       22
  31 #define MIPS_R_S7       23
  32 #define MIPS_R_SP       29
  33 #define MIPS_R_RA       31
  34
  35 /* Conditional codes */
  36 #define MIPS_COND_EQ    0x1
  37 #define MIPS_COND_GE    (0x1 << 1)
  38 #define MIPS_COND_GT    (0x1 << 2)
  39 #define MIPS_COND_NE    (0x1 << 3)
  40 #define MIPS_COND_ALL   (0x1 << 4)
  41 /* Conditionals on X register or K immediate */
  42 #define MIPS_COND_X     (0x1 << 5)
  43 #define MIPS_COND_K     (0x1 << 6)
  44
  45 #define r_ret   MIPS_R_V0
  46
  47 /*
  48  * Use 2 scratch registers to avoid pipeline interlocks.
  49  * There is no overhead during epilogue and prologue since
  50  * any of the $s0-$s6 registers will only be preserved if
  51  * they are going to actually be used.
  52  */
  53 #define r_skb_hl        MIPS_R_S0 /* skb header length */
  54 #define r_skb_data      MIPS_R_S1 /* skb actual data */
  55 #define r_off           MIPS_R_S2
  56 #define r_A             MIPS_R_S3
  57 #define r_X             MIPS_R_S4
  58 #define r_skb           MIPS_R_S5
  59 #define r_M             MIPS_R_S6
  60 #define r_skb_len       MIPS_R_S7
  61 #define r_s0            MIPS_R_T4 /* scratch reg 1 */
  62 #define r_s1            MIPS_R_T5 /* scratch reg 2 */
  63 #define r_tmp_imm       MIPS_R_T6 /* No need to preserve this */
  64 #define r_tmp           MIPS_R_T7 /* No need to preserve this */
  65 #define r_zero          MIPS_R_ZERO
  66 #define r_sp            MIPS_R_SP
  67 #define r_ra            MIPS_R_RA
  68
  69 #ifndef __ASSEMBLY__
  70
  71 /* Declare ASM helpers */
  72
  73 #define DECLARE_LOAD_FUNC(func) \
  74         extern u8 func(unsigned long *skb, int offset); \
  75         extern u8 func##_negative(unsigned long *skb, int offset); \
  76         extern u8 func##_positive(unsigned long *skb, int offset)
  77
  78 DECLARE_LOAD_FUNC(sk_load_word);
  79 DECLARE_LOAD_FUNC(sk_load_half);
  80 DECLARE_LOAD_FUNC(sk_load_byte);
  81
  82 #endif
  83
  84 #endif /* BPF_JIT_MIPS_OP_H */