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Thomas Gleixnerb886d83c2019-06-01 10:08:55 +02001/* SPDX-License-Identifier: GPL-2.0-only */
Naveen N. Rao156d0e22016-06-22 21:55:07 +05302/*
3 * bpf_jit64.h: BPF JIT compiler for PPC64
4 *
5 * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
6 * IBM Corporation
Naveen N. Rao156d0e22016-06-22 21:55:07 +05307 */
8#ifndef _BPF_JIT64_H
9#define _BPF_JIT64_H
10
11#include "bpf_jit.h"
12
13/*
14 * Stack layout:
Naveen N. Rao7b847f52016-09-24 02:05:00 +053015 * Ensure the top half (upto local_tmp_var) stays consistent
16 * with our redzone usage.
Naveen N. Rao156d0e22016-06-22 21:55:07 +053017 *
18 * [ prev sp ] <-------------
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +020019 * [ nv gpr save area ] 6*8 |
Naveen N. Rao7b847f52016-09-24 02:05:00 +053020 * [ tail_call_cnt ] 8 |
21 * [ local_tmp_var ] 8 |
Sandipan Dasac0761e2017-09-02 00:23:01 +053022 * fp (r31) --> [ ebpf stack space ] upto 512 |
Naveen N. Rao156d0e22016-06-22 21:55:07 +053023 * [ frame header ] 32/112 |
24 * sp (r1) ---> [ stack pointer ] --------------
25 */
26
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +020027/* for gpr non volatile registers BPG_REG_6 to 10 */
28#define BPF_PPC_STACK_SAVE (6*8)
Naveen N. Rao7b847f52016-09-24 02:05:00 +053029/* for bpf JIT code internal usage */
30#define BPF_PPC_STACK_LOCALS 16
Sandipan Dasac0761e2017-09-02 00:23:01 +053031/* stack frame excluding BPF stack, ensure this is quadword aligned */
32#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \
Naveen N. Rao7b847f52016-09-24 02:05:00 +053033 BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
Naveen N. Rao156d0e22016-06-22 21:55:07 +053034
35#ifndef __ASSEMBLY__
36
37/* BPF register usage */
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +020038#define TMP_REG_1 (MAX_BPF_JIT_REG + 0)
39#define TMP_REG_2 (MAX_BPF_JIT_REG + 1)
Naveen N. Rao156d0e22016-06-22 21:55:07 +053040
41/* BPF to ppc register mappings */
42static const int b2p[] = {
43 /* function return value */
44 [BPF_REG_0] = 8,
45 /* function arguments */
46 [BPF_REG_1] = 3,
47 [BPF_REG_2] = 4,
48 [BPF_REG_3] = 5,
49 [BPF_REG_4] = 6,
50 [BPF_REG_5] = 7,
51 /* non volatile registers */
52 [BPF_REG_6] = 27,
53 [BPF_REG_7] = 28,
54 [BPF_REG_8] = 29,
55 [BPF_REG_9] = 30,
56 /* frame pointer aka BPF_REG_10 */
57 [BPF_REG_FP] = 31,
58 /* eBPF jit internal registers */
Naveen N. Raob7b70132016-09-24 02:05:02 +053059 [BPF_REG_AX] = 2,
Naveen N. Rao156d0e22016-06-22 21:55:07 +053060 [TMP_REG_1] = 9,
61 [TMP_REG_2] = 10
62};
63
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +020064/* PPC NVR range -- update this if we ever use NVRs below r27 */
65#define BPF_PPC_NVR_MIN 27
Naveen N. Rao156d0e22016-06-22 21:55:07 +053066
Naveen N. Rao86be36f2019-03-15 20:21:19 +053067/*
68 * WARNING: These can use TMP_REG_2 if the offset is not at word boundary,
69 * so ensure that it isn't in use already.
70 */
71#define PPC_BPF_LL(r, base, i) do { \
72 if ((i) % 4) { \
73 PPC_LI(b2p[TMP_REG_2], (i)); \
74 PPC_LDX(r, base, b2p[TMP_REG_2]); \
75 } else \
76 PPC_LD(r, base, i); \
77 } while(0)
78#define PPC_BPF_STL(r, base, i) do { \
79 if ((i) % 4) { \
80 PPC_LI(b2p[TMP_REG_2], (i)); \
81 PPC_STDX(r, base, b2p[TMP_REG_2]); \
82 } else \
83 PPC_STD(r, base, i); \
84 } while(0)
85#define PPC_BPF_STLU(r, base, i) do { PPC_STDU(r, base, i); } while(0)
86
Naveen N. Rao156d0e22016-06-22 21:55:07 +053087#define SEEN_FUNC 0x1000 /* might call external helpers */
88#define SEEN_STACK 0x2000 /* uses BPF stack */
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +020089#define SEEN_TAILCALL 0x4000 /* uses tail calls */
Naveen N. Rao156d0e22016-06-22 21:55:07 +053090
91struct codegen_context {
92 /*
93 * This is used to track register usage as well
94 * as calls to external helpers.
95 * - register usage is tracked with corresponding
Daniel Borkmanndbf44daf2018-05-04 01:08:21 +020096 * bits (r3-r10 and r27-r31)
Naveen N. Rao156d0e22016-06-22 21:55:07 +053097 * - rest of the bits can be used to track other
98 * things -- for now, we use bits 16 to 23
99 * encoded in SEEN_* macros above
100 */
101 unsigned int seen;
102 unsigned int idx;
Sandipan Dasac0761e2017-09-02 00:23:01 +0530103 unsigned int stack_size;
Naveen N. Rao156d0e22016-06-22 21:55:07 +0530104};
105
106#endif /* !__ASSEMBLY__ */
107
108#endif