tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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_ADDI(d, a, i) EMIT(PPC_INST_ADDI | ___PPC_RT(d) | \
44 ___PPC_RA(a) | IMM_L(i))
45#define PPC_MR(d, a) PPC_OR(d, a, a)
46#define PPC_LI(r, i) PPC_ADDI(r, 0, i)
47#define PPC_ADDIS(d, a, i) EMIT(PPC_INST_ADDIS | \
48 ___PPC_RT(d) | ___PPC_RA(a) | IMM_L(i))
49#define PPC_LIS(r, i) PPC_ADDIS(r, 0, i)
50#define PPC_STD(r, base, i) EMIT(PPC_INST_STD | ___PPC_RS(r) | \
51 ___PPC_RA(base) | ((i) & 0xfffc))
52#define PPC_STDU(r, base, i) EMIT(PPC_INST_STDU | ___PPC_RS(r) | \
53 ___PPC_RA(base) | ((i) & 0xfffc))
54#define PPC_STW(r, base, i) EMIT(PPC_INST_STW | ___PPC_RS(r) | \
55 ___PPC_RA(base) | IMM_L(i))
56#define PPC_STWU(r, base, i) EMIT(PPC_INST_STWU | ___PPC_RS(r) | \
57 ___PPC_RA(base) | IMM_L(i))
58#define PPC_STH(r, base, i) EMIT(PPC_INST_STH | ___PPC_RS(r) | \
59 ___PPC_RA(base) | IMM_L(i))
60#define PPC_STB(r, base, i) EMIT(PPC_INST_STB | ___PPC_RS(r) | \
61 ___PPC_RA(base) | IMM_L(i))
62
63#define PPC_LBZ(r, base, i) EMIT(PPC_INST_LBZ | ___PPC_RT(r) | \
64 ___PPC_RA(base) | IMM_L(i))
65#define PPC_LD(r, base, i) EMIT(PPC_INST_LD | ___PPC_RT(r) | \
66 ___PPC_RA(base) | IMM_L(i))
67#define PPC_LWZ(r, base, i) EMIT(PPC_INST_LWZ | ___PPC_RT(r) | \
68 ___PPC_RA(base) | IMM_L(i))
69#define PPC_LHZ(r, base, i) EMIT(PPC_INST_LHZ | ___PPC_RT(r) | \
70 ___PPC_RA(base) | IMM_L(i))
71#define PPC_LHBRX(r, base, b) EMIT(PPC_INST_LHBRX | ___PPC_RT(r) | \
72 ___PPC_RA(base) | ___PPC_RB(b))
73#define PPC_LDBRX(r, base, b) EMIT(PPC_INST_LDBRX | ___PPC_RT(r) | \
74 ___PPC_RA(base) | ___PPC_RB(b))
75
76#define PPC_BPF_LDARX(t, a, b, eh) EMIT(PPC_INST_LDARX | ___PPC_RT(t) | \
77 ___PPC_RA(a) | ___PPC_RB(b) | \
78 __PPC_EH(eh))
79#define PPC_BPF_LWARX(t, a, b, eh) EMIT(PPC_INST_LWARX | ___PPC_RT(t) | \
80 ___PPC_RA(a) | ___PPC_RB(b) | \
81 __PPC_EH(eh))
82#define PPC_BPF_STWCX(s, a, b) EMIT(PPC_INST_STWCX | ___PPC_RS(s) | \
83 ___PPC_RA(a) | ___PPC_RB(b))
84#define PPC_BPF_STDCX(s, a, b) EMIT(PPC_INST_STDCX | ___PPC_RS(s) | \
85 ___PPC_RA(a) | ___PPC_RB(b))
86
87#ifdef CONFIG_PPC64
88#define PPC_BPF_LL(r, base, i) do { PPC_LD(r, base, i); } while(0)
89#define PPC_BPF_STL(r, base, i) do { PPC_STD(r, base, i); } while(0)
90#define PPC_BPF_STLU(r, base, i) do { PPC_STDU(r, base, i); } while(0)
91#else
92#define PPC_BPF_LL(r, base, i) do { PPC_LWZ(r, base, i); } while(0)
93#define PPC_BPF_STL(r, base, i) do { PPC_STW(r, base, i); } while(0)
94#define PPC_BPF_STLU(r, base, i) do { PPC_STWU(r, base, i); } while(0)
95#endif
96
97#define PPC_CMPWI(a, i) EMIT(PPC_INST_CMPWI | ___PPC_RA(a) | IMM_L(i))
98#define PPC_CMPDI(a, i) EMIT(PPC_INST_CMPDI | ___PPC_RA(a) | IMM_L(i))
99#define PPC_CMPW(a, b) EMIT(PPC_INST_CMPW | ___PPC_RA(a) | \
100 ___PPC_RB(b))
101#define PPC_CMPD(a, b) EMIT(PPC_INST_CMPD | ___PPC_RA(a) | \
102 ___PPC_RB(b))
103#define PPC_CMPLWI(a, i) EMIT(PPC_INST_CMPLWI | ___PPC_RA(a) | IMM_L(i))
104#define PPC_CMPLDI(a, i) EMIT(PPC_INST_CMPLDI | ___PPC_RA(a) | IMM_L(i))
105#define PPC_CMPLW(a, b) EMIT(PPC_INST_CMPLW | ___PPC_RA(a) | \
106 ___PPC_RB(b))
107#define PPC_CMPLD(a, b) EMIT(PPC_INST_CMPLD | ___PPC_RA(a) | \
108 ___PPC_RB(b))
109
110#define PPC_SUB(d, a, b) EMIT(PPC_INST_SUB | ___PPC_RT(d) | \
111 ___PPC_RB(a) | ___PPC_RA(b))
112#define PPC_ADD(d, a, b) EMIT(PPC_INST_ADD | ___PPC_RT(d) | \
113 ___PPC_RA(a) | ___PPC_RB(b))
114#define PPC_MULD(d, a, b) EMIT(PPC_INST_MULLD | ___PPC_RT(d) | \
115 ___PPC_RA(a) | ___PPC_RB(b))
116#define PPC_MULW(d, a, b) EMIT(PPC_INST_MULLW | ___PPC_RT(d) | \
117 ___PPC_RA(a) | ___PPC_RB(b))
118#define PPC_MULHWU(d, a, b) EMIT(PPC_INST_MULHWU | ___PPC_RT(d) | \
119 ___PPC_RA(a) | ___PPC_RB(b))
120#define PPC_MULI(d, a, i) EMIT(PPC_INST_MULLI | ___PPC_RT(d) | \
121 ___PPC_RA(a) | IMM_L(i))
122#define PPC_DIVWU(d, a, b) EMIT(PPC_INST_DIVWU | ___PPC_RT(d) | \
123 ___PPC_RA(a) | ___PPC_RB(b))
124#define PPC_DIVD(d, a, b) EMIT(PPC_INST_DIVD | ___PPC_RT(d) | \
125 ___PPC_RA(a) | ___PPC_RB(b))
126#define PPC_AND(d, a, b) EMIT(PPC_INST_AND | ___PPC_RA(d) | \
127 ___PPC_RS(a) | ___PPC_RB(b))
128#define PPC_ANDI(d, a, i) EMIT(PPC_INST_ANDI | ___PPC_RA(d) | \
129 ___PPC_RS(a) | IMM_L(i))
130#define PPC_AND_DOT(d, a, b) EMIT(PPC_INST_ANDDOT | ___PPC_RA(d) | \
131 ___PPC_RS(a) | ___PPC_RB(b))
132#define PPC_OR(d, a, b) EMIT(PPC_INST_OR | ___PPC_RA(d) | \
133 ___PPC_RS(a) | ___PPC_RB(b))
134#define PPC_MR(d, a) PPC_OR(d, a, a)
135#define PPC_ORI(d, a, i) EMIT(PPC_INST_ORI | ___PPC_RA(d) | \
136 ___PPC_RS(a) | IMM_L(i))
137#define PPC_ORIS(d, a, i) EMIT(PPC_INST_ORIS | ___PPC_RA(d) | \
138 ___PPC_RS(a) | IMM_L(i))
139#define PPC_XOR(d, a, b) EMIT(PPC_INST_XOR | ___PPC_RA(d) | \
140 ___PPC_RS(a) | ___PPC_RB(b))
141#define PPC_XORI(d, a, i) EMIT(PPC_INST_XORI | ___PPC_RA(d) | \
142 ___PPC_RS(a) | IMM_L(i))
143#define PPC_XORIS(d, a, i) EMIT(PPC_INST_XORIS | ___PPC_RA(d) | \
144 ___PPC_RS(a) | IMM_L(i))
145#define PPC_EXTSW(d, a) EMIT(PPC_INST_EXTSW | ___PPC_RA(d) | \
146 ___PPC_RS(a))
147#define PPC_SLW(d, a, s) EMIT(PPC_INST_SLW | ___PPC_RA(d) | \
148 ___PPC_RS(a) | ___PPC_RB(s))
149#define PPC_SLD(d, a, s) EMIT(PPC_INST_SLD | ___PPC_RA(d) | \
150 ___PPC_RS(a) | ___PPC_RB(s))
151#define PPC_SRW(d, a, s) EMIT(PPC_INST_SRW | ___PPC_RA(d) | \
152 ___PPC_RS(a) | ___PPC_RB(s))
153#define PPC_SRD(d, a, s) EMIT(PPC_INST_SRD | ___PPC_RA(d) | \
154 ___PPC_RS(a) | ___PPC_RB(s))
155#define PPC_SRAD(d, a, s) EMIT(PPC_INST_SRAD | ___PPC_RA(d) | \
156 ___PPC_RS(a) | ___PPC_RB(s))
157#define PPC_SRADI(d, a, i) EMIT(PPC_INST_SRADI | ___PPC_RA(d) | \
158 ___PPC_RS(a) | __PPC_SH(i) | \
159 (((i) & 0x20) >> 4))
160#define PPC_RLWINM(d, a, i, mb, me) EMIT(PPC_INST_RLWINM | ___PPC_RA(d) | \
161 ___PPC_RS(a) | __PPC_SH(i) | \
162 __PPC_MB(mb) | __PPC_ME(me))
163#define PPC_RLWIMI(d, a, i, mb, me) EMIT(PPC_INST_RLWIMI | ___PPC_RA(d) | \
164 ___PPC_RS(a) | __PPC_SH(i) | \
165 __PPC_MB(mb) | __PPC_ME(me))
166#define PPC_RLDICL(d, a, i, mb) EMIT(PPC_INST_RLDICL | ___PPC_RA(d) | \
167 ___PPC_RS(a) | __PPC_SH(i) | \
168 __PPC_MB64(mb) | (((i) & 0x20) >> 4))
169#define PPC_RLDICR(d, a, i, me) EMIT(PPC_INST_RLDICR | ___PPC_RA(d) | \
170 ___PPC_RS(a) | __PPC_SH(i) | \
171 __PPC_ME64(me) | (((i) & 0x20) >> 4))
172
173/* slwi = rlwinm Rx, Ry, n, 0, 31-n */
174#define PPC_SLWI(d, a, i) PPC_RLWINM(d, a, i, 0, 31-(i))
175/* srwi = rlwinm Rx, Ry, 32-n, n, 31 */
176#define PPC_SRWI(d, a, i) PPC_RLWINM(d, a, 32-(i), i, 31)
177/* sldi = rldicr Rx, Ry, n, 63-n */
178#define PPC_SLDI(d, a, i) PPC_RLDICR(d, a, i, 63-(i))
179/* sldi = rldicl Rx, Ry, 64-n, n */
180#define PPC_SRDI(d, a, i) PPC_RLDICL(d, a, 64-(i), i)
181
182#define PPC_NEG(d, a) EMIT(PPC_INST_NEG | ___PPC_RT(d) | ___PPC_RA(a))
183
184/* Long jump; (unconditional 'branch') */
185#define PPC_JMP(dest) EMIT(PPC_INST_BRANCH | \
186 (((dest) - (ctx->idx * 4)) & 0x03fffffc))
187/* "cond" here covers BO:BI fields. */
188#define PPC_BCC_SHORT(cond, dest) EMIT(PPC_INST_BRANCH_COND | \
189 (((cond) & 0x3ff) << 16) | \
190 (((dest) - (ctx->idx * 4)) & \
191 0xfffc))
192/* Sign-extended 32-bit immediate load */
193#define PPC_LI32(d, i) do { \
194 if ((int)(uintptr_t)(i) >= -32768 && \
195 (int)(uintptr_t)(i) < 32768) \
196 PPC_LI(d, i); \
197 else { \
198 PPC_LIS(d, IMM_H(i)); \
199 if (IMM_L(i)) \
200 PPC_ORI(d, d, IMM_L(i)); \
201 } } while(0)
202
203#define PPC_LI64(d, i) do { \
204 if ((long)(i) >= -2147483648 && \
205 (long)(i) < 2147483648) \
206 PPC_LI32(d, i); \
207 else { \
208 if (!((uintptr_t)(i) & 0xffff800000000000ULL)) \
209 PPC_LI(d, ((uintptr_t)(i) >> 32) & 0xffff); \
210 else { \
211 PPC_LIS(d, ((uintptr_t)(i) >> 48)); \
212 if ((uintptr_t)(i) & 0x0000ffff00000000ULL) \
213 PPC_ORI(d, d, \
214 ((uintptr_t)(i) >> 32) & 0xffff); \
215 } \
216 PPC_SLDI(d, d, 32); \
217 if ((uintptr_t)(i) & 0x00000000ffff0000ULL) \
218 PPC_ORIS(d, d, \
219 ((uintptr_t)(i) >> 16) & 0xffff); \
220 if ((uintptr_t)(i) & 0x000000000000ffffULL) \
221 PPC_ORI(d, d, (uintptr_t)(i) & 0xffff); \
222 } } while (0)
223
224#ifdef CONFIG_PPC64
225#define PPC_FUNC_ADDR(d,i) do { PPC_LI64(d, i); } while(0)
226#else
227#define PPC_FUNC_ADDR(d,i) do { PPC_LI32(d, i); } while(0)
228#endif
229
230static inline bool is_nearbranch(int offset)
231{
232 return (offset < 32768) && (offset >= -32768);
233}
234
235/*
236 * The fly in the ointment of code size changing from pass to pass is
237 * avoided by padding the short branch case with a NOP. If code size differs
238 * with different branch reaches we will have the issue of code moving from
239 * one pass to the next and will need a few passes to converge on a stable
240 * state.
241 */
242#define PPC_BCC(cond, dest) do { \
243 if (is_nearbranch((dest) - (ctx->idx * 4))) { \
244 PPC_BCC_SHORT(cond, dest); \
245 PPC_NOP(); \
246 } else { \
247 /* Flip the 'T or F' bit to invert comparison */ \
248 PPC_BCC_SHORT(cond ^ COND_CMP_TRUE, (ctx->idx+2)*4); \
249 PPC_JMP(dest); \
250 } } while(0)
251
252/* To create a branch condition, select a bit of cr0... */
253#define CR0_LT 0
254#define CR0_GT 1
255#define CR0_EQ 2
256/* ...and modify BO[3] */
257#define COND_CMP_TRUE 0x100
258#define COND_CMP_FALSE 0x000
259/* Together, they make all required comparisons: */
260#define COND_GT (CR0_GT | COND_CMP_TRUE)
261#define COND_GE (CR0_LT | COND_CMP_FALSE)
262#define COND_EQ (CR0_EQ | COND_CMP_TRUE)
263#define COND_NE (CR0_EQ | COND_CMP_FALSE)
264#define COND_LT (CR0_LT | COND_CMP_TRUE)
265
266#endif
267
268#endif