arch/sparc/net/bpf_jit_asm.S

   1 #include <asm/ptrace.h>
   2
   3 #include "bpf_jit.h"
   4
   5 #ifdef CONFIG_SPARC64
   6 #define SAVE_SZ         176
   7 #define SCRATCH_OFF     STACK_BIAS + 128
   8 #define BE_PTR(label)   be,pn %xcc, label
   9 #else
  10 #define SAVE_SZ         96
  11 #define SCRATCH_OFF     72
  12 #define BE_PTR(label)   be label
  13 #endif
  14
  15 #define SKF_MAX_NEG_OFF (-0x200000) /* SKF_LL_OFF from filter.h */
  16
  17         .text
  18         .globl  bpf_jit_load_word
  19 bpf_jit_load_word:
  20         cmp     r_OFF, 0
  21         bl      bpf_slow_path_word_neg
  22          nop
  23         .globl  bpf_jit_load_word_positive_offset
  24 bpf_jit_load_word_positive_offset:
  25         sub     r_HEADLEN, r_OFF, r_TMP
  26         cmp     r_TMP, 3
  27         ble     bpf_slow_path_word
  28          add    r_SKB_DATA, r_OFF, r_TMP
  29         andcc   r_TMP, 3, %g0
  30         bne     load_word_unaligned
  31          nop
  32         retl
  33          ld     [r_TMP], r_A
  34 load_word_unaligned:
  35         ldub    [r_TMP + 0x0], r_OFF
  36         ldub    [r_TMP + 0x1], r_TMP2
  37         sll     r_OFF, 8, r_OFF
  38         or      r_OFF, r_TMP2, r_OFF
  39         ldub    [r_TMP + 0x2], r_TMP2
  40         sll     r_OFF, 8, r_OFF
  41         or      r_OFF, r_TMP2, r_OFF
  42         ldub    [r_TMP + 0x3], r_TMP2
  43         sll     r_OFF, 8, r_OFF
  44         retl
  45          or     r_OFF, r_TMP2, r_A
  46
  47         .globl  bpf_jit_load_half
  48 bpf_jit_load_half:
  49         cmp     r_OFF, 0
  50         bl      bpf_slow_path_half_neg
  51          nop
  52         .globl  bpf_jit_load_half_positive_offset
  53 bpf_jit_load_half_positive_offset:
  54         sub     r_HEADLEN, r_OFF, r_TMP
  55         cmp     r_TMP, 1
  56         ble     bpf_slow_path_half
  57          add    r_SKB_DATA, r_OFF, r_TMP
  58         andcc   r_TMP, 1, %g0
  59         bne     load_half_unaligned
  60          nop
  61         retl
  62          lduh   [r_TMP], r_A
  63 load_half_unaligned:
  64         ldub    [r_TMP + 0x0], r_OFF
  65         ldub    [r_TMP + 0x1], r_TMP2
  66         sll     r_OFF, 8, r_OFF
  67         retl
  68          or     r_OFF, r_TMP2, r_A
  69
  70         .globl  bpf_jit_load_byte
  71 bpf_jit_load_byte:
  72         cmp     r_OFF, 0
  73         bl      bpf_slow_path_byte_neg
  74          nop
  75         .globl  bpf_jit_load_byte_positive_offset
  76 bpf_jit_load_byte_positive_offset:
  77         cmp     r_OFF, r_HEADLEN
  78         bge     bpf_slow_path_byte
  79          nop
  80         retl
  81          ldub   [r_SKB_DATA + r_OFF], r_A
  82
  83         .globl  bpf_jit_load_byte_msh
  84 bpf_jit_load_byte_msh:
  85         cmp     r_OFF, 0
  86         bl      bpf_slow_path_byte_msh_neg
  87          nop
  88         .globl  bpf_jit_load_byte_msh_positive_offset
  89 bpf_jit_load_byte_msh_positive_offset:
  90         cmp     r_OFF, r_HEADLEN
  91         bge     bpf_slow_path_byte_msh
  92          nop
  93         ldub    [r_SKB_DATA + r_OFF], r_OFF
  94         and     r_OFF, 0xf, r_OFF
  95         retl
  96          sll    r_OFF, 2, r_X
  97
  98 #define bpf_slow_path_common(LEN)       \
  99         save    %sp, -SAVE_SZ, %sp;     \
 100         mov     %i0, %o0;               \
 101         mov     r_OFF, %o1;             \
 102         add     %fp, SCRATCH_OFF, %o2;  \
 103         call    skb_copy_bits;          \
 104          mov    (LEN), %o3;             \
 105         cmp     %o0, 0;                 \
 106         restore;
 107
 108 bpf_slow_path_word:
 109         bpf_slow_path_common(4)
 110         bl      bpf_error
 111          ld     [%sp + SCRATCH_OFF], r_A
 112         retl
 113          nop
 114 bpf_slow_path_half:
 115         bpf_slow_path_common(2)
 116         bl      bpf_error
 117          lduh   [%sp + SCRATCH_OFF], r_A
 118         retl
 119          nop
 120 bpf_slow_path_byte:
 121         bpf_slow_path_common(1)
 122         bl      bpf_error
 123          ldub   [%sp + SCRATCH_OFF], r_A
 124         retl
 125          nop
 126 bpf_slow_path_byte_msh:
 127         bpf_slow_path_common(1)
 128         bl      bpf_error
 129          ldub   [%sp + SCRATCH_OFF], r_A
 130         and     r_OFF, 0xf, r_OFF
 131         retl
 132          sll    r_OFF, 2, r_X
 133
 134 #define bpf_negative_common(LEN)                        \
 135         save    %sp, -SAVE_SZ, %sp;                     \
 136         mov     %i0, %o0;                               \
 137         mov     r_OFF, %o1;                             \
 138         call    bpf_internal_load_pointer_neg_helper;   \
 139          mov    (LEN), %o2;                             \
 140         mov     %o0, r_TMP;                             \
 141         cmp     %o0, 0;                                 \
 142         BE_PTR(bpf_error);                              \
 143          restore;
 144
 145 bpf_slow_path_word_neg:
 146         sethi   %hi(SKF_MAX_NEG_OFF), r_TMP
 147         cmp     r_OFF, r_TMP
 148         bl      bpf_error
 149          nop
 150         .globl  bpf_jit_load_word_negative_offset
 151 bpf_jit_load_word_negative_offset:
 152         bpf_negative_common(4)
 153         andcc   r_TMP, 3, %g0
 154         bne     load_word_unaligned
 155          nop
 156         retl
 157          ld     [r_TMP], r_A
 158
 159 bpf_slow_path_half_neg:
 160         sethi   %hi(SKF_MAX_NEG_OFF), r_TMP
 161         cmp     r_OFF, r_TMP
 162         bl      bpf_error
 163          nop
 164         .globl  bpf_jit_load_half_negative_offset
 165 bpf_jit_load_half_negative_offset:
 166         bpf_negative_common(2)
 167         andcc   r_TMP, 1, %g0
 168         bne     load_half_unaligned
 169          nop
 170         retl
 171          lduh   [r_TMP], r_A
 172
 173 bpf_slow_path_byte_neg:
 174         sethi   %hi(SKF_MAX_NEG_OFF), r_TMP
 175         cmp     r_OFF, r_TMP
 176         bl      bpf_error
 177          nop
 178         .globl  bpf_jit_load_byte_negative_offset
 179 bpf_jit_load_byte_negative_offset:
 180         bpf_negative_common(1)
 181         retl
 182          ldub   [r_TMP], r_A
 183
 184 bpf_slow_path_byte_msh_neg:
 185         sethi   %hi(SKF_MAX_NEG_OFF), r_TMP
 186         cmp     r_OFF, r_TMP
 187         bl      bpf_error
 188          nop
 189         .globl  bpf_jit_load_byte_msh_negative_offset
 190 bpf_jit_load_byte_msh_negative_offset:
 191         bpf_negative_common(1)
 192         ldub    [r_TMP], r_OFF
 193         and     r_OFF, 0xf, r_OFF
 194         retl
 195          sll    r_OFF, 2, r_X
 196
 197 bpf_error:
 198         /* Make the JIT program return zero.  The JIT epilogue
 199          * stores away the original %o7 into r_saved_O7.  The
 200          * normal leaf function return is to use "retl" which
 201          * would evalute to "jmpl %o7 + 8, %g0" but we want to
 202          * use the saved value thus the sequence you see here.
 203          */
 204         jmpl    r_saved_O7 + 8, %g0
 205          clr    %o0