LXR linux/arch/mips/net/bpf

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * Just-In-Time compiler for BPF filters on MIPS
   4 *
   5 * Copyright (c) 2014 Imagination Technologies Ltd.
   6 * Author: Markos Chandras <markos.chandras@imgtec.com>
   7 */
   8
   9#ifndef BPF_JIT_MIPS_OP_H
  10#define BPF_JIT_MIPS_OP_H
  11
  12/* Registers used by JIT */
  13#define MIPS_R_ZERO     0
  14#define MIPS_R_V0       2
  15#define MIPS_R_A0       4
  16#define MIPS_R_A1       5
  17#define MIPS_R_T4       12
  18#define MIPS_R_T5       13
  19#define MIPS_R_T6       14
  20#define MIPS_R_T7       15
  21#define MIPS_R_S0       16
  22#define MIPS_R_S1       17
  23#define MIPS_R_S2       18
  24#define MIPS_R_S3       19
  25#define MIPS_R_S4       20
  26#define MIPS_R_S5       21
  27#define MIPS_R_S6       22
  28#define MIPS_R_S7       23
  29#define MIPS_R_SP       29
  30#define MIPS_R_RA       31
  31
  32/* Conditional codes */
  33#define MIPS_COND_EQ    0x1
  34#define MIPS_COND_GE    (0x1 << 1)
  35#define MIPS_COND_GT    (0x1 << 2)
  36#define MIPS_COND_NE    (0x1 << 3)
  37#define MIPS_COND_ALL   (0x1 << 4)
  38/* Conditionals on X register or K immediate */
  39#define MIPS_COND_X     (0x1 << 5)
  40#define MIPS_COND_K     (0x1 << 6)
  41
  42#define r_ret   MIPS_R_V0
  43
  44/*
  45 * Use 2 scratch registers to avoid pipeline interlocks.
  46 * There is no overhead during epilogue and prologue since
  47 * any of the $s0-$s6 registers will only be preserved if
  48 * they are going to actually be used.
  49 */
  50#define r_skb_hl        MIPS_R_S0 /* skb header length */
  51#define r_skb_data      MIPS_R_S1 /* skb actual data */
  52#define r_off           MIPS_R_S2
  53#define r_A             MIPS_R_S3
  54#define r_X             MIPS_R_S4
  55#define r_skb           MIPS_R_S5
  56#define r_M             MIPS_R_S6
  57#define r_skb_len       MIPS_R_S7
  58#define r_s0            MIPS_R_T4 /* scratch reg 1 */
  59#define r_s1            MIPS_R_T5 /* scratch reg 2 */
  60#define r_tmp_imm       MIPS_R_T6 /* No need to preserve this */
  61#define r_tmp           MIPS_R_T7 /* No need to preserve this */
  62#define r_zero          MIPS_R_ZERO
  63#define r_sp            MIPS_R_SP
  64#define r_ra            MIPS_R_RA
  65
  66#ifndef __ASSEMBLY__
  67
  68/* Declare ASM helpers */
  69
  70#define DECLARE_LOAD_FUNC(func) \
  71        extern u8 func(unsigned long *skb, int offset); \
  72        extern u8 func##_negative(unsigned long *skb, int offset); \
  73        extern u8 func##_positive(unsigned long *skb, int offset)
  74
  75DECLARE_LOAD_FUNC(sk_load_word);
  76DECLARE_LOAD_FUNC(sk_load_half);
  77DECLARE_LOAD_FUNC(sk_load_byte);
  78
  79#endif
  80
  81#endif /* BPF_JIT_MIPS_OP_H */
  82