LXR linux/arch/mips/net/bpf

   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
  78DECLARE_LOAD_FUNC(sk_load_word);
  79DECLARE_LOAD_FUNC(sk_load_half);
  80DECLARE_LOAD_FUNC(sk_load_byte);
  81
  82#endif
  83
  84#endif /* BPF_JIT_MIPS_OP_H */
  85