arch/powerpc/net/bpf_jit32.h

   1 /*
   2  * bpf_jit32.h: BPF JIT compiler for PPC
   3  *
   4  * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation
   5  *
   6  * Split from bpf_jit.h
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; version 2
  11  * of the License.
  12  */
  13 #ifndef _BPF_JIT32_H
  14 #define _BPF_JIT32_H
  15
  16 #include "bpf_jit.h"
  17
  18 #ifdef CONFIG_PPC64
  19 #define BPF_PPC_STACK_R3_OFF    48
  20 #define BPF_PPC_STACK_LOCALS    32
  21 #define BPF_PPC_STACK_BASIC     (48+64)
  22 #define BPF_PPC_STACK_SAVE      (18*8)
  23 #define BPF_PPC_STACKFRAME      (BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \
  24                                  BPF_PPC_STACK_SAVE)
  25 #define BPF_PPC_SLOWPATH_FRAME  (48+64)
  26 #else
  27 #define BPF_PPC_STACK_R3_OFF    24
  28 #define BPF_PPC_STACK_LOCALS    16
  29 #define BPF_PPC_STACK_BASIC     (24+32)
  30 #define BPF_PPC_STACK_SAVE      (18*4)
  31 #define BPF_PPC_STACKFRAME      (BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \
  32                                  BPF_PPC_STACK_SAVE)
  33 #define BPF_PPC_SLOWPATH_FRAME  (24+32)
  34 #endif
  35
  36 #define REG_SZ         (BITS_PER_LONG/8)
  37
  38 /*
  39  * Generated code register usage:
  40  *
  41  * As normal PPC C ABI (e.g. r1=sp, r2=TOC), with:
  42  *
  43  * skb          r3      (Entry parameter)
  44  * A register   r4
  45  * X register   r5
  46  * addr param   r6
  47  * r7-r10       scratch
  48  * skb->data    r14
  49  * skb headlen  r15     (skb->len - skb->data_len)
  50  * m[0]         r16
  51  * m[...]       ...
  52  * m[15]        r31
  53  */
  54 #define r_skb           3
  55 #define r_ret           3
  56 #define r_A             4
  57 #define r_X             5
  58 #define r_addr          6
  59 #define r_scratch1      7
  60 #define r_scratch2      8
  61 #define r_D             14
  62 #define r_HL            15
  63 #define r_M             16
  64
  65 #ifndef __ASSEMBLY__
  66
  67 /*
  68  * Assembly helpers from arch/powerpc/net/bpf_jit.S:
  69  */
  70 #define DECLARE_LOAD_FUNC(func) \
  71         extern u8 func[], func##_negative_offset[], func##_positive_offset[]
  72
  73 DECLARE_LOAD_FUNC(sk_load_word);
  74 DECLARE_LOAD_FUNC(sk_load_half);
  75 DECLARE_LOAD_FUNC(sk_load_byte);
  76 DECLARE_LOAD_FUNC(sk_load_byte_msh);
  77
  78 #define PPC_LBZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LBZ(r, base, i);   \
  79                 else {  PPC_ADDIS(r, base, IMM_HA(i));                        \
  80                         PPC_LBZ(r, r, IMM_L(i)); } } while(0)
  81
  82 #define PPC_LD_OFFS(r, base, i) do { if ((i) < 32768) PPC_LD(r, base, i);     \
  83                 else {  PPC_ADDIS(r, base, IMM_HA(i));                        \
  84                         PPC_LD(r, r, IMM_L(i)); } } while(0)
  85
  86 #define PPC_LWZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LWZ(r, base, i);   \
  87                 else {  PPC_ADDIS(r, base, IMM_HA(i));                        \
  88                         PPC_LWZ(r, r, IMM_L(i)); } } while(0)
  89
  90 #define PPC_LHZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LHZ(r, base, i);   \
  91                 else {  PPC_ADDIS(r, base, IMM_HA(i));                        \
  92                         PPC_LHZ(r, r, IMM_L(i)); } } while(0)
  93
  94 #ifdef CONFIG_PPC64
  95 #define PPC_LL_OFFS(r, base, i) do { PPC_LD_OFFS(r, base, i); } while(0)
  96 #else
  97 #define PPC_LL_OFFS(r, base, i) do { PPC_LWZ_OFFS(r, base, i); } while(0)
  98 #endif
  99
 100 #ifdef CONFIG_SMP
 101 #ifdef CONFIG_PPC64
 102 #define PPC_BPF_LOAD_CPU(r)             \
 103         do { BUILD_BUG_ON(FIELD_SIZEOF(struct paca_struct, paca_index) != 2);   \
 104                 PPC_LHZ_OFFS(r, 13, offsetof(struct paca_struct, paca_index));  \
 105         } while (0)
 106 #else
 107 #define PPC_BPF_LOAD_CPU(r)     \
 108         do { BUILD_BUG_ON(FIELD_SIZEOF(struct thread_info, cpu) != 4);          \
 109                 PPC_LHZ_OFFS(r, (1 & ~(THREAD_SIZE - 1)),                       \
 110                                 offsetof(struct thread_info, cpu));             \
 111         } while(0)
 112 #endif
 113 #else
 114 #define PPC_BPF_LOAD_CPU(r) do { PPC_LI(r, 0); } while(0)
 115 #endif
 116
 117 #define PPC_LHBRX_OFFS(r, base, i) \
 118                 do { PPC_LI32(r, i); PPC_LHBRX(r, r, base); } while(0)
 119 #ifdef __LITTLE_ENDIAN__
 120 #define PPC_NTOHS_OFFS(r, base, i)      PPC_LHBRX_OFFS(r, base, i)
 121 #else
 122 #define PPC_NTOHS_OFFS(r, base, i)      PPC_LHZ_OFFS(r, base, i)
 123 #endif
 124
 125 #define SEEN_DATAREF 0x10000 /* might call external helpers */
 126 #define SEEN_XREG    0x20000 /* X reg is used */
 127 #define SEEN_MEM     0x40000 /* SEEN_MEM+(1<<n) = use mem[n] for temporary
 128                               * storage */
 129 #define SEEN_MEM_MSK 0x0ffff
 130
 131 struct codegen_context {
 132         unsigned int seen;
 133         unsigned int idx;
 134         int pc_ret0; /* bpf index of first RET #0 instruction (if any) */
 135 };
 136
 137 #endif
 138
 139 #endif