xref: /openbmc/linux/arch/powerpc/net/bpf_jit.h (revision d2ba09c1)
1 /*
2  * bpf_jit.h: BPF JIT compiler for PPC
3  *
4  * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation
5  * 	     2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
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_JIT_H
13 #define _BPF_JIT_H
14 
15 #ifndef __ASSEMBLY__
16 
17 #include <asm/types.h>
18 
19 #ifdef PPC64_ELF_ABI_v1
20 #define FUNCTION_DESCR_SIZE	24
21 #else
22 #define FUNCTION_DESCR_SIZE	0
23 #endif
24 
25 /*
26  * 16-bit immediate helper macros: HA() is for use with sign-extending instrs
27  * (e.g. LD, ADDI).  If the bottom 16 bits is "-ve", add another bit into the
28  * top half to negate the effect (i.e. 0xffff + 1 = 0x(1)0000).
29  */
30 #define IMM_H(i)		((uintptr_t)(i)>>16)
31 #define IMM_HA(i)		(((uintptr_t)(i)>>16) +			      \
32 					(((uintptr_t)(i) & 0x8000) >> 15))
33 #define IMM_L(i)		((uintptr_t)(i) & 0xffff)
34 
35 #define PLANT_INSTR(d, idx, instr)					      \
36 	do { if (d) { (d)[idx] = instr; } idx++; } while (0)
37 #define EMIT(instr)		PLANT_INSTR(image, ctx->idx, instr)
38 
39 #define PPC_NOP()		EMIT(PPC_INST_NOP)
40 #define PPC_BLR()		EMIT(PPC_INST_BLR)
41 #define PPC_BLRL()		EMIT(PPC_INST_BLRL)
42 #define PPC_MTLR(r)		EMIT(PPC_INST_MTLR | ___PPC_RT(r))
43 #define PPC_BCTR()		EMIT(PPC_INST_BCTR)
44 #define PPC_MTCTR(r)		EMIT(PPC_INST_MTCTR | ___PPC_RT(r))
45 #define PPC_ADDI(d, a, i)	EMIT(PPC_INST_ADDI | ___PPC_RT(d) |	      \
46 				     ___PPC_RA(a) | IMM_L(i))
47 #define PPC_MR(d, a)		PPC_OR(d, a, a)
48 #define PPC_LI(r, i)		PPC_ADDI(r, 0, i)
49 #define PPC_ADDIS(d, a, i)	EMIT(PPC_INST_ADDIS |			      \
50 				     ___PPC_RT(d) | ___PPC_RA(a) | IMM_L(i))
51 #define PPC_LIS(r, i)		PPC_ADDIS(r, 0, i)
52 #define PPC_STD(r, base, i)	EMIT(PPC_INST_STD | ___PPC_RS(r) |	      \
53 				     ___PPC_RA(base) | ((i) & 0xfffc))
54 #define PPC_STDU(r, base, i)	EMIT(PPC_INST_STDU | ___PPC_RS(r) |	      \
55 				     ___PPC_RA(base) | ((i) & 0xfffc))
56 #define PPC_STW(r, base, i)	EMIT(PPC_INST_STW | ___PPC_RS(r) |	      \
57 				     ___PPC_RA(base) | IMM_L(i))
58 #define PPC_STWU(r, base, i)	EMIT(PPC_INST_STWU | ___PPC_RS(r) |	      \
59 				     ___PPC_RA(base) | IMM_L(i))
60 #define PPC_STH(r, base, i)	EMIT(PPC_INST_STH | ___PPC_RS(r) |	      \
61 				     ___PPC_RA(base) | IMM_L(i))
62 #define PPC_STB(r, base, i)	EMIT(PPC_INST_STB | ___PPC_RS(r) |	      \
63 				     ___PPC_RA(base) | IMM_L(i))
64 
65 #define PPC_LBZ(r, base, i)	EMIT(PPC_INST_LBZ | ___PPC_RT(r) |	      \
66 				     ___PPC_RA(base) | IMM_L(i))
67 #define PPC_LD(r, base, i)	EMIT(PPC_INST_LD | ___PPC_RT(r) |	      \
68 				     ___PPC_RA(base) | IMM_L(i))
69 #define PPC_LWZ(r, base, i)	EMIT(PPC_INST_LWZ | ___PPC_RT(r) |	      \
70 				     ___PPC_RA(base) | IMM_L(i))
71 #define PPC_LHZ(r, base, i)	EMIT(PPC_INST_LHZ | ___PPC_RT(r) |	      \
72 				     ___PPC_RA(base) | IMM_L(i))
73 #define PPC_LHBRX(r, base, b)	EMIT(PPC_INST_LHBRX | ___PPC_RT(r) |	      \
74 				     ___PPC_RA(base) | ___PPC_RB(b))
75 #define PPC_LDBRX(r, base, b)	EMIT(PPC_INST_LDBRX | ___PPC_RT(r) |	      \
76 				     ___PPC_RA(base) | ___PPC_RB(b))
77 
78 #define PPC_BPF_LDARX(t, a, b, eh) EMIT(PPC_INST_LDARX | ___PPC_RT(t) |	      \
79 					___PPC_RA(a) | ___PPC_RB(b) |	      \
80 					__PPC_EH(eh))
81 #define PPC_BPF_LWARX(t, a, b, eh) EMIT(PPC_INST_LWARX | ___PPC_RT(t) |	      \
82 					___PPC_RA(a) | ___PPC_RB(b) |	      \
83 					__PPC_EH(eh))
84 #define PPC_BPF_STWCX(s, a, b)	EMIT(PPC_INST_STWCX | ___PPC_RS(s) |	      \
85 					___PPC_RA(a) | ___PPC_RB(b))
86 #define PPC_BPF_STDCX(s, a, b)	EMIT(PPC_INST_STDCX | ___PPC_RS(s) |	      \
87 					___PPC_RA(a) | ___PPC_RB(b))
88 
89 #ifdef CONFIG_PPC64
90 #define PPC_BPF_LL(r, base, i) do { PPC_LD(r, base, i); } while(0)
91 #define PPC_BPF_STL(r, base, i) do { PPC_STD(r, base, i); } while(0)
92 #define PPC_BPF_STLU(r, base, i) do { PPC_STDU(r, base, i); } while(0)
93 #else
94 #define PPC_BPF_LL(r, base, i) do { PPC_LWZ(r, base, i); } while(0)
95 #define PPC_BPF_STL(r, base, i) do { PPC_STW(r, base, i); } while(0)
96 #define PPC_BPF_STLU(r, base, i) do { PPC_STWU(r, base, i); } while(0)
97 #endif
98 
99 #define PPC_CMPWI(a, i)		EMIT(PPC_INST_CMPWI | ___PPC_RA(a) | IMM_L(i))
100 #define PPC_CMPDI(a, i)		EMIT(PPC_INST_CMPDI | ___PPC_RA(a) | IMM_L(i))
101 #define PPC_CMPW(a, b)		EMIT(PPC_INST_CMPW | ___PPC_RA(a) |	      \
102 					___PPC_RB(b))
103 #define PPC_CMPD(a, b)		EMIT(PPC_INST_CMPD | ___PPC_RA(a) |	      \
104 					___PPC_RB(b))
105 #define PPC_CMPLWI(a, i)	EMIT(PPC_INST_CMPLWI | ___PPC_RA(a) | IMM_L(i))
106 #define PPC_CMPLDI(a, i)	EMIT(PPC_INST_CMPLDI | ___PPC_RA(a) | IMM_L(i))
107 #define PPC_CMPLW(a, b)		EMIT(PPC_INST_CMPLW | ___PPC_RA(a) |	      \
108 					___PPC_RB(b))
109 #define PPC_CMPLD(a, b)		EMIT(PPC_INST_CMPLD | ___PPC_RA(a) |	      \
110 					___PPC_RB(b))
111 
112 #define PPC_SUB(d, a, b)	EMIT(PPC_INST_SUB | ___PPC_RT(d) |	      \
113 				     ___PPC_RB(a) | ___PPC_RA(b))
114 #define PPC_ADD(d, a, b)	EMIT(PPC_INST_ADD | ___PPC_RT(d) |	      \
115 				     ___PPC_RA(a) | ___PPC_RB(b))
116 #define PPC_MULD(d, a, b)	EMIT(PPC_INST_MULLD | ___PPC_RT(d) |	      \
117 				     ___PPC_RA(a) | ___PPC_RB(b))
118 #define PPC_MULW(d, a, b)	EMIT(PPC_INST_MULLW | ___PPC_RT(d) |	      \
119 				     ___PPC_RA(a) | ___PPC_RB(b))
120 #define PPC_MULHWU(d, a, b)	EMIT(PPC_INST_MULHWU | ___PPC_RT(d) |	      \
121 				     ___PPC_RA(a) | ___PPC_RB(b))
122 #define PPC_MULI(d, a, i)	EMIT(PPC_INST_MULLI | ___PPC_RT(d) |	      \
123 				     ___PPC_RA(a) | IMM_L(i))
124 #define PPC_DIVWU(d, a, b)	EMIT(PPC_INST_DIVWU | ___PPC_RT(d) |	      \
125 				     ___PPC_RA(a) | ___PPC_RB(b))
126 #define PPC_DIVD(d, a, b)	EMIT(PPC_INST_DIVD | ___PPC_RT(d) |	      \
127 				     ___PPC_RA(a) | ___PPC_RB(b))
128 #define PPC_AND(d, a, b)	EMIT(PPC_INST_AND | ___PPC_RA(d) |	      \
129 				     ___PPC_RS(a) | ___PPC_RB(b))
130 #define PPC_ANDI(d, a, i)	EMIT(PPC_INST_ANDI | ___PPC_RA(d) |	      \
131 				     ___PPC_RS(a) | IMM_L(i))
132 #define PPC_AND_DOT(d, a, b)	EMIT(PPC_INST_ANDDOT | ___PPC_RA(d) |	      \
133 				     ___PPC_RS(a) | ___PPC_RB(b))
134 #define PPC_OR(d, a, b)		EMIT(PPC_INST_OR | ___PPC_RA(d) |	      \
135 				     ___PPC_RS(a) | ___PPC_RB(b))
136 #define PPC_MR(d, a)		PPC_OR(d, a, a)
137 #define PPC_ORI(d, a, i)	EMIT(PPC_INST_ORI | ___PPC_RA(d) |	      \
138 				     ___PPC_RS(a) | IMM_L(i))
139 #define PPC_ORIS(d, a, i)	EMIT(PPC_INST_ORIS | ___PPC_RA(d) |	      \
140 				     ___PPC_RS(a) | IMM_L(i))
141 #define PPC_XOR(d, a, b)	EMIT(PPC_INST_XOR | ___PPC_RA(d) |	      \
142 				     ___PPC_RS(a) | ___PPC_RB(b))
143 #define PPC_XORI(d, a, i)	EMIT(PPC_INST_XORI | ___PPC_RA(d) |	      \
144 				     ___PPC_RS(a) | IMM_L(i))
145 #define PPC_XORIS(d, a, i)	EMIT(PPC_INST_XORIS | ___PPC_RA(d) |	      \
146 				     ___PPC_RS(a) | IMM_L(i))
147 #define PPC_EXTSW(d, a)		EMIT(PPC_INST_EXTSW | ___PPC_RA(d) |	      \
148 				     ___PPC_RS(a))
149 #define PPC_SLW(d, a, s)	EMIT(PPC_INST_SLW | ___PPC_RA(d) |	      \
150 				     ___PPC_RS(a) | ___PPC_RB(s))
151 #define PPC_SLD(d, a, s)	EMIT(PPC_INST_SLD | ___PPC_RA(d) |	      \
152 				     ___PPC_RS(a) | ___PPC_RB(s))
153 #define PPC_SRW(d, a, s)	EMIT(PPC_INST_SRW | ___PPC_RA(d) |	      \
154 				     ___PPC_RS(a) | ___PPC_RB(s))
155 #define PPC_SRD(d, a, s)	EMIT(PPC_INST_SRD | ___PPC_RA(d) |	      \
156 				     ___PPC_RS(a) | ___PPC_RB(s))
157 #define PPC_SRAD(d, a, s)	EMIT(PPC_INST_SRAD | ___PPC_RA(d) |	      \
158 				     ___PPC_RS(a) | ___PPC_RB(s))
159 #define PPC_SRADI(d, a, i)	EMIT(PPC_INST_SRADI | ___PPC_RA(d) |	      \
160 				     ___PPC_RS(a) | __PPC_SH64(i))
161 #define PPC_RLWINM(d, a, i, mb, me)	EMIT(PPC_INST_RLWINM | ___PPC_RA(d) | \
162 					___PPC_RS(a) | __PPC_SH(i) |	      \
163 					__PPC_MB(mb) | __PPC_ME(me))
164 #define PPC_RLWIMI(d, a, i, mb, me)	EMIT(PPC_INST_RLWIMI | ___PPC_RA(d) | \
165 					___PPC_RS(a) | __PPC_SH(i) |	      \
166 					__PPC_MB(mb) | __PPC_ME(me))
167 #define PPC_RLDICL(d, a, i, mb)		EMIT(PPC_INST_RLDICL | ___PPC_RA(d) | \
168 					___PPC_RS(a) | __PPC_SH64(i) |	      \
169 					__PPC_MB64(mb))
170 #define PPC_RLDICR(d, a, i, me)		EMIT(PPC_INST_RLDICR | ___PPC_RA(d) | \
171 					___PPC_RS(a) | __PPC_SH64(i) |	      \
172 					__PPC_ME64(me))
173 
174 /* slwi = rlwinm Rx, Ry, n, 0, 31-n */
175 #define PPC_SLWI(d, a, i)	PPC_RLWINM(d, a, i, 0, 31-(i))
176 /* srwi = rlwinm Rx, Ry, 32-n, n, 31 */
177 #define PPC_SRWI(d, a, i)	PPC_RLWINM(d, a, 32-(i), i, 31)
178 /* sldi = rldicr Rx, Ry, n, 63-n */
179 #define PPC_SLDI(d, a, i)	PPC_RLDICR(d, a, i, 63-(i))
180 /* sldi = rldicl Rx, Ry, 64-n, n */
181 #define PPC_SRDI(d, a, i)	PPC_RLDICL(d, a, 64-(i), i)
182 
183 #define PPC_NEG(d, a)		EMIT(PPC_INST_NEG | ___PPC_RT(d) | ___PPC_RA(a))
184 
185 /* Long jump; (unconditional 'branch') */
186 #define PPC_JMP(dest)		EMIT(PPC_INST_BRANCH |			      \
187 				     (((dest) - (ctx->idx * 4)) & 0x03fffffc))
188 /* "cond" here covers BO:BI fields. */
189 #define PPC_BCC_SHORT(cond, dest)	EMIT(PPC_INST_BRANCH_COND |	      \
190 					     (((cond) & 0x3ff) << 16) |	      \
191 					     (((dest) - (ctx->idx * 4)) &     \
192 					      0xfffc))
193 /* Sign-extended 32-bit immediate load */
194 #define PPC_LI32(d, i)		do {					      \
195 		if ((int)(uintptr_t)(i) >= -32768 &&			      \
196 				(int)(uintptr_t)(i) < 32768)		      \
197 			PPC_LI(d, i);					      \
198 		else {							      \
199 			PPC_LIS(d, IMM_H(i));				      \
200 			if (IMM_L(i))					      \
201 				PPC_ORI(d, d, IMM_L(i));		      \
202 		} } while(0)
203 
204 #define PPC_LI64(d, i)		do {					      \
205 		if ((long)(i) >= -2147483648 &&				      \
206 				(long)(i) < 2147483648)			      \
207 			PPC_LI32(d, i);					      \
208 		else {							      \
209 			if (!((uintptr_t)(i) & 0xffff800000000000ULL))	      \
210 				PPC_LI(d, ((uintptr_t)(i) >> 32) & 0xffff);   \
211 			else {						      \
212 				PPC_LIS(d, ((uintptr_t)(i) >> 48));	      \
213 				if ((uintptr_t)(i) & 0x0000ffff00000000ULL)   \
214 					PPC_ORI(d, d,			      \
215 					  ((uintptr_t)(i) >> 32) & 0xffff);   \
216 			}						      \
217 			PPC_SLDI(d, d, 32);				      \
218 			if ((uintptr_t)(i) & 0x00000000ffff0000ULL)	      \
219 				PPC_ORIS(d, d,				      \
220 					 ((uintptr_t)(i) >> 16) & 0xffff);    \
221 			if ((uintptr_t)(i) & 0x000000000000ffffULL)	      \
222 				PPC_ORI(d, d, (uintptr_t)(i) & 0xffff);	      \
223 		} } while (0)
224 
225 #ifdef CONFIG_PPC64
226 #define PPC_FUNC_ADDR(d,i) do { PPC_LI64(d, i); } while(0)
227 #else
228 #define PPC_FUNC_ADDR(d,i) do { PPC_LI32(d, i); } while(0)
229 #endif
230 
231 static inline bool is_nearbranch(int offset)
232 {
233 	return (offset < 32768) && (offset >= -32768);
234 }
235 
236 /*
237  * The fly in the ointment of code size changing from pass to pass is
238  * avoided by padding the short branch case with a NOP.	 If code size differs
239  * with different branch reaches we will have the issue of code moving from
240  * one pass to the next and will need a few passes to converge on a stable
241  * state.
242  */
243 #define PPC_BCC(cond, dest)	do {					      \
244 		if (is_nearbranch((dest) - (ctx->idx * 4))) {		      \
245 			PPC_BCC_SHORT(cond, dest);			      \
246 			PPC_NOP();					      \
247 		} else {						      \
248 			/* Flip the 'T or F' bit to invert comparison */      \
249 			PPC_BCC_SHORT(cond ^ COND_CMP_TRUE, (ctx->idx+2)*4);  \
250 			PPC_JMP(dest);					      \
251 		} } while(0)
252 
253 /* To create a branch condition, select a bit of cr0... */
254 #define CR0_LT		0
255 #define CR0_GT		1
256 #define CR0_EQ		2
257 /* ...and modify BO[3] */
258 #define COND_CMP_TRUE	0x100
259 #define COND_CMP_FALSE	0x000
260 /* Together, they make all required comparisons: */
261 #define COND_GT		(CR0_GT | COND_CMP_TRUE)
262 #define COND_GE		(CR0_LT | COND_CMP_FALSE)
263 #define COND_EQ		(CR0_EQ | COND_CMP_TRUE)
264 #define COND_NE		(CR0_EQ | COND_CMP_FALSE)
265 #define COND_LT		(CR0_LT | COND_CMP_TRUE)
266 #define COND_LE		(CR0_GT | COND_CMP_FALSE)
267 
268 #endif
269 
270 #endif
271