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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 
70 DECLARE_LOAD_FUNC(sk_load_word);
71 DECLARE_LOAD_FUNC(sk_load_half);
72 DECLARE_LOAD_FUNC(sk_load_byte);
73 DECLARE_LOAD_FUNC(sk_load_byte_msh);
74 
75 #define PPC_LBZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LBZ(r, base, i);   \
76 		else {	PPC_ADDIS(r, base, IMM_HA(i));			      \
77 			PPC_LBZ(r, r, IMM_L(i)); } } while(0)
78 
79 #define PPC_LD_OFFS(r, base, i) do { if ((i) < 32768) PPC_LD(r, base, i);     \
80 		else {	PPC_ADDIS(r, base, IMM_HA(i));			      \
81 			PPC_LD(r, r, IMM_L(i)); } } while(0)
82 
83 #define PPC_LWZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LWZ(r, base, i);   \
84 		else {	PPC_ADDIS(r, base, IMM_HA(i));			      \
85 			PPC_LWZ(r, r, IMM_L(i)); } } while(0)
86 
87 #define PPC_LHZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LHZ(r, base, i);   \
88 		else {	PPC_ADDIS(r, base, IMM_HA(i));			      \
89 			PPC_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(FIELD_SIZEOF(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(FIELD_SIZEOF(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 { PPC_LI(r, 0); } while(0)
111 #endif
112 
113 #define PPC_LHBRX_OFFS(r, base, i) \
114 		do { PPC_LI32(r, i); PPC_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 { PPC_LWZ(r, base, i); } while(0)
122 #define PPC_BPF_STL(r, base, i) do { PPC_STW(r, base, i); } while(0)
123 #define PPC_BPF_STLU(r, base, i) do { PPC_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 
131 struct 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