arch/s390/net/bpf_jit.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * BPF Jit compiler defines
   4  *
   5  * Copyright IBM Corp. 2012,2015
   6  *
   7  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   8  *            Michael Holzheu <holzheu@linux.vnet.ibm.com>
   9  */
  10
  11 #ifndef __ARCH_S390_NET_BPF_JIT_H
  12 #define __ARCH_S390_NET_BPF_JIT_H
  13
  14 #ifndef __ASSEMBLY__
  15
  16 #include <linux/filter.h>
  17 #include <linux/types.h>
  18
  19 extern u8 sk_load_word_pos[], sk_load_half_pos[], sk_load_byte_pos[];
  20 extern u8 sk_load_word[], sk_load_half[], sk_load_byte[];
  21
  22 #endif /* __ASSEMBLY__ */
  23
  24 /*
  25  * Stackframe layout (packed stack):
  26  *
  27  *                                  ^ high
  28  *            +---------------+     |
  29  *            | old backchain |     |
  30  *            +---------------+     |
  31  *            |   r15 - r6    |     |
  32  *            +---------------+     |
  33  *            | 4 byte align  |     |
  34  *            | tail_call_cnt |     |
  35  * BFP     -> +===============+     |
  36  *            |               |     |
  37  *            |   BPF stack   |     |
  38  *            |               |     |
  39  *            +---------------+     |
  40  *            | 8 byte skbp   |     |
  41  * R15+176 -> +---------------+     |
  42  *            | 8 byte hlen   |     |
  43  * R15+168 -> +---------------+     |
  44  *            | 4 byte align  |     |
  45  *            +---------------+     |
  46  *            | 4 byte temp   |     |
  47  *            | for bpf_jit.S |     |
  48  * R15+160 -> +---------------+     |
  49  *            | new backchain |     |
  50  * R15+152 -> +---------------+     |
  51  *            | + 152 byte SA |     |
  52  * R15     -> +---------------+     + low
  53  *
  54  * We get 160 bytes stack space from calling function, but only use
  55  * 12 * 8 byte for old backchain, r15..r6, and tail_call_cnt.
  56  */
  57 #define STK_SPACE       (MAX_BPF_STACK + 8 + 8 + 4 + 4 + 160)
  58 #define STK_160_UNUSED  (160 - 12 * 8)
  59 #define STK_OFF         (STK_SPACE - STK_160_UNUSED)
  60 #define STK_OFF_TMP     160     /* Offset of tmp buffer on stack */
  61 #define STK_OFF_HLEN    168     /* Offset of SKB header length on stack */
  62 #define STK_OFF_SKBP    176     /* Offset of SKB pointer on stack */
  63
  64 #define STK_OFF_R6      (160 - 11 * 8)  /* Offset of r6 on stack */
  65 #define STK_OFF_TCCNT   (160 - 12 * 8)  /* Offset of tail_call_cnt on stack */
  66
  67 /* Offset to skip condition code check */
  68 #define OFF_OK          4
  69
  70 #endif /* __ARCH_S390_NET_BPF_JIT_H */