1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * bpf_jit32.h: BPF JIT compiler for PPC
4 *
5 * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation
6 *
7 * Split from bpf_jit.h
8 */
9#ifndef _BPF_JIT32_H
10#define _BPF_JIT32_H
11
12#include <asm/asm-compat.h>
13#include "bpf_jit.h"
14
15#ifdef CONFIG_PPC64
16#define BPF_PPC_STACK_R3_OFF	48
17#define BPF_PPC_STACK_LOCALS	32
18#define BPF_PPC_STACK_BASIC	(48+64)
19#define BPF_PPC_STACK_SAVE	(18*8)
20#define BPF_PPC_STACKFRAME	(BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \
21				 BPF_PPC_STACK_SAVE)
22#define BPF_PPC_SLOWPATH_FRAME	(48+64)
23#else
24#define BPF_PPC_STACK_R3_OFF	24
25#define BPF_PPC_STACK_LOCALS	16
26#define BPF_PPC_STACK_BASIC	(24+32)
27#define BPF_PPC_STACK_SAVE	(18*4)
28#define BPF_PPC_STACKFRAME	(BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \
29				 BPF_PPC_STACK_SAVE)
30#define BPF_PPC_SLOWPATH_FRAME	(24+32)
31#endif
32
33#define REG_SZ         (BITS_PER_LONG/8)
34
35/*
36 * Generated code register usage:
37 *
38 * As normal PPC C ABI (e.g. r1=sp, r2=TOC), with:
39 *
40 * skb		r3	(Entry parameter)
41 * A register	r4
42 * X register	r5
43 * addr param	r6
44 * r7-r10	scratch
45 * skb->data	r14
46 * skb headlen	r15	(skb->len - skb->data_len)
47 * m[0]		r16
48 * m[...]	...
49 * m[15]	r31
50 */
51#define r_skb		3
52#define r_ret		3
53#define r_A		4
54#define r_X		5
55#define r_addr		6
56#define r_scratch1	7
57#define r_scratch2	8
58#define r_D		14
59#define r_HL		15
60#define r_M		16
61
62#ifndef __ASSEMBLY__
63
64/*
65 * Assembly helpers from arch/powerpc/net/bpf_jit.S:
66 */
67#define DECLARE_LOAD_FUNC(func)	\
68	extern u8 func[], func##_negative_offset[], func##_positive_offset[]
69
70DECLARE_LOAD_FUNC(sk_load_word);
71DECLARE_LOAD_FUNC(sk_load_half);
72DECLARE_LOAD_FUNC(sk_load_byte);
73DECLARE_LOAD_FUNC(sk_load_byte_msh);
74
75#define PPC_LBZ_OFFS(r, base, i) do { if ((i) < 32768) EMIT(PPC_RAW_LBZ(r, base, i));   \
76		else {	EMIT(PPC_RAW_ADDIS(r, base, IMM_HA(i)));	      \
77			EMIT(PPC_RAW_LBZ(r, r, IMM_L(i))); } } while(0)
78
79#define PPC_LD_OFFS(r, base, i) do { if ((i) < 32768) EMIT(PPC_RAW_LD(r, base, i));     \
80		else {	EMIT(PPC_RAW_ADDIS(r, base, IMM_HA(i)));			\
81			EMIT(PPC_RAW_LD(r, r, IMM_L(i))); } } while(0)
82
83#define PPC_LWZ_OFFS(r, base, i) do { if ((i) < 32768) EMIT(PPC_RAW_LWZ(r, base, i));   \
84		else {	EMIT(PPC_RAW_ADDIS(r, base, IMM_HA(i)));			\
85			EMIT(PPC_RAW_LWZ(r, r, IMM_L(i))); } } while(0)
86
87#define PPC_LHZ_OFFS(r, base, i) do { if ((i) < 32768) EMIT(PPC_RAW_LHZ(r, base, i));   \
88		else {	EMIT(PPC_RAW_ADDIS(r, base, IMM_HA(i)));			\
89			EMIT(PPC_RAW_LHZ(r, r, IMM_L(i))); } } while(0)
90
91#ifdef CONFIG_PPC64
92#define PPC_LL_OFFS(r, base, i) do { PPC_LD_OFFS(r, base, i); } while(0)
93#else
94#define PPC_LL_OFFS(r, base, i) do { PPC_LWZ_OFFS(r, base, i); } while(0)
95#endif
96
97#ifdef CONFIG_SMP
98#ifdef CONFIG_PPC64
99#define PPC_BPF_LOAD_CPU(r)		\
100	do { BUILD_BUG_ON(sizeof_field(struct paca_struct, paca_index) != 2);	\
101		PPC_LHZ_OFFS(r, 13, offsetof(struct paca_struct, paca_index));	\
102	} while (0)
103#else
104#define PPC_BPF_LOAD_CPU(r)     \
105	do { BUILD_BUG_ON(sizeof_field(struct task_struct, cpu) != 4);		\
106		PPC_LHZ_OFFS(r, 2, offsetof(struct task_struct, cpu));		\
107	} while(0)
108#endif
109#else
110#define PPC_BPF_LOAD_CPU(r) do { EMIT(PPC_RAW_LI(r, 0)); } while(0)
111#endif
112
113#define PPC_LHBRX_OFFS(r, base, i) \
114		do { PPC_LI32(r, i); EMIT(PPC_RAW_LHBRX(r, r, base)); } while(0)
115#ifdef __LITTLE_ENDIAN__
116#define PPC_NTOHS_OFFS(r, base, i)	PPC_LHBRX_OFFS(r, base, i)
117#else
118#define PPC_NTOHS_OFFS(r, base, i)	PPC_LHZ_OFFS(r, base, i)
119#endif
120
121#define PPC_BPF_LL(r, base, i) do { EMIT(PPC_RAW_LWZ(r, base, i)); } while(0)
122#define PPC_BPF_STL(r, base, i) do { EMIT(PPC_RAW_STW(r, base, i)); } while(0)
123#define PPC_BPF_STLU(r, base, i) do { EMIT(PPC_RAW_STWU(r, base, i)); } while(0)
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
131struct 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
140