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review.shift-gmbh.com / SHIFTPHONES / kernel / common / 0db37915d912e8dc6588f25da76d3ed36718d92f / . / arch / powerpc / net / bpf_jit64.h
blob: 3609be4692b35e948f3ceff98c39c1b3bdaea744 [file] [log] [blame]
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]1/*
2 * bpf_jit64.h: BPF JIT compiler for PPC64
3 *
4 * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
5 * IBM Corporation
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; version 2
10 * of the License.
11 */
12#ifndef _BPF_JIT64_H
13#define _BPF_JIT64_H
14
15#include "bpf_jit.h"
16
17/*
18 * Stack layout:
Naveen N. Rao7b847f52016-09-24 02:05:00 +0530[diff] [blame]19 * Ensure the top half (upto local_tmp_var) stays consistent
20 * with our redzone usage.
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]21 *
22 * [ prev sp ] <-------------
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +0200[diff] [blame]23 * [ nv gpr save area ] 6*8 |
Naveen N. Rao7b847f52016-09-24 02:05:00 +0530[diff] [blame]24 * [ tail_call_cnt ] 8 |
25 * [ local_tmp_var ] 8 |
Sandipan Dasac0761e2017-09-02 00:23:01 +0530[diff] [blame]26 * fp (r31) --> [ ebpf stack space ] upto 512 |
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]27 * [ frame header ] 32/112 |
28 * sp (r1) ---> [ stack pointer ] --------------
29 */
30
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +0200[diff] [blame]31/* for gpr non volatile registers BPG_REG_6 to 10 */
32#define BPF_PPC_STACK_SAVE (6*8)
Naveen N. Rao7b847f52016-09-24 02:05:00 +0530[diff] [blame]33/* for bpf JIT code internal usage */
34#define BPF_PPC_STACK_LOCALS 16
Sandipan Dasac0761e2017-09-02 00:23:01 +0530[diff] [blame]35/* stack frame excluding BPF stack, ensure this is quadword aligned */
36#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \
Naveen N. Rao7b847f52016-09-24 02:05:00 +0530[diff] [blame]37 BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]38
39#ifndef __ASSEMBLY__
40
41/* BPF register usage */
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +0200[diff] [blame]42#define TMP_REG_1 (MAX_BPF_JIT_REG + 0)
43#define TMP_REG_2 (MAX_BPF_JIT_REG + 1)
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]44
45/* BPF to ppc register mappings */
46static const int b2p[] = {
47 /* function return value */
48 [BPF_REG_0] = 8,
49 /* function arguments */
50 [BPF_REG_1] = 3,
51 [BPF_REG_2] = 4,
52 [BPF_REG_3] = 5,
53 [BPF_REG_4] = 6,
54 [BPF_REG_5] = 7,
55 /* non volatile registers */
56 [BPF_REG_6] = 27,
57 [BPF_REG_7] = 28,
58 [BPF_REG_8] = 29,
59 [BPF_REG_9] = 30,
60 /* frame pointer aka BPF_REG_10 */
61 [BPF_REG_FP] = 31,
62 /* eBPF jit internal registers */
Naveen N. Raob7b70132016-09-24 02:05:02 +0530[diff] [blame]63 [BPF_REG_AX] = 2,
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]64 [TMP_REG_1] = 9,
65 [TMP_REG_2] = 10
66};
67
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +0200[diff] [blame]68/* PPC NVR range -- update this if we ever use NVRs below r27 */
69#define BPF_PPC_NVR_MIN 27
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]70
71#define SEEN_FUNC 0x1000 /* might call external helpers */
72#define SEEN_STACK 0x2000 /* uses BPF stack */
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +0200[diff] [blame]73#define SEEN_TAILCALL 0x4000 /* uses tail calls */
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]74
75struct codegen_context {
76 /*
77 * This is used to track register usage as well
78 * as calls to external helpers.
79 * - register usage is tracked with corresponding
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +0200[diff] [blame]80 * bits (r3-r10 and r27-r31)
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]81 * - rest of the bits can be used to track other
82 * things -- for now, we use bits 16 to 23
83 * encoded in SEEN_* macros above
84 */
85 unsigned int seen;
86 unsigned int idx;
Sandipan Dasac0761e2017-09-02 00:23:01 +0530[diff] [blame]87 unsigned int stack_size;
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530[diff] [blame]88};
89
90#endif /* !__ASSEMBLY__ */
91
92#endif