summaryrefslogtreecommitdiff
path: root/arch/loongarch/net/bpf_jit.c
blob: e73323d759d0b85b275aa389fc684b74d12cb13e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
// SPDX-License-Identifier: GPL-2.0-only
/*
 * BPF JIT compiler for LoongArch
 *
 * Copyright (C) 2022 Loongson Technology Corporation Limited
 */
#include "bpf_jit.h"

#define REG_TCC		LOONGARCH_GPR_A6
#define TCC_SAVED	LOONGARCH_GPR_S5

#define SAVE_RA		BIT(0)
#define SAVE_TCC	BIT(1)

static const int regmap[] = {
	/* return value from in-kernel function, and exit value for eBPF program */
	[BPF_REG_0] = LOONGARCH_GPR_A5,
	/* arguments from eBPF program to in-kernel function */
	[BPF_REG_1] = LOONGARCH_GPR_A0,
	[BPF_REG_2] = LOONGARCH_GPR_A1,
	[BPF_REG_3] = LOONGARCH_GPR_A2,
	[BPF_REG_4] = LOONGARCH_GPR_A3,
	[BPF_REG_5] = LOONGARCH_GPR_A4,
	/* callee saved registers that in-kernel function will preserve */
	[BPF_REG_6] = LOONGARCH_GPR_S0,
	[BPF_REG_7] = LOONGARCH_GPR_S1,
	[BPF_REG_8] = LOONGARCH_GPR_S2,
	[BPF_REG_9] = LOONGARCH_GPR_S3,
	/* read-only frame pointer to access stack */
	[BPF_REG_FP] = LOONGARCH_GPR_S4,
	/* temporary register for blinding constants */
	[BPF_REG_AX] = LOONGARCH_GPR_T0,
};

static void mark_call(struct jit_ctx *ctx)
{
	ctx->flags |= SAVE_RA;
}

static void mark_tail_call(struct jit_ctx *ctx)
{
	ctx->flags |= SAVE_TCC;
}

static bool seen_call(struct jit_ctx *ctx)
{
	return (ctx->flags & SAVE_RA);
}

static bool seen_tail_call(struct jit_ctx *ctx)
{
	return (ctx->flags & SAVE_TCC);
}

static u8 tail_call_reg(struct jit_ctx *ctx)
{
	if (seen_call(ctx))
		return TCC_SAVED;

	return REG_TCC;
}

/*
 * eBPF prog stack layout:
 *
 *                                        high
 * original $sp ------------> +-------------------------+ <--LOONGARCH_GPR_FP
 *                            |           $ra           |
 *                            +-------------------------+
 *                            |           $fp           |
 *                            +-------------------------+
 *                            |           $s0           |
 *                            +-------------------------+
 *                            |           $s1           |
 *                            +-------------------------+
 *                            |           $s2           |
 *                            +-------------------------+
 *                            |           $s3           |
 *                            +-------------------------+
 *                            |           $s4           |
 *                            +-------------------------+
 *                            |           $s5           |
 *                            +-------------------------+ <--BPF_REG_FP
 *                            |  prog->aux->stack_depth |
 *                            |        (optional)       |
 * current $sp -------------> +-------------------------+
 *                                        low
 */
static void build_prologue(struct jit_ctx *ctx)
{
	int stack_adjust = 0, store_offset, bpf_stack_adjust;

	bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16);

	/* To store ra, fp, s0, s1, s2, s3, s4 and s5. */
	stack_adjust += sizeof(long) * 8;

	stack_adjust = round_up(stack_adjust, 16);
	stack_adjust += bpf_stack_adjust;

	/*
	 * First instruction initializes the tail call count (TCC).
	 * On tail call we skip this instruction, and the TCC is
	 * passed in REG_TCC from the caller.
	 */
	emit_insn(ctx, addid, REG_TCC, LOONGARCH_GPR_ZERO, MAX_TAIL_CALL_CNT);

	emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_adjust);

	store_offset = stack_adjust - sizeof(long);
	emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, store_offset);

	store_offset -= sizeof(long);
	emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, store_offset);

	store_offset -= sizeof(long);
	emit_insn(ctx, std, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, store_offset);

	store_offset -= sizeof(long);
	emit_insn(ctx, std, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, store_offset);

	store_offset -= sizeof(long);
	emit_insn(ctx, std, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, store_offset);

	store_offset -= sizeof(long);
	emit_insn(ctx, std, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, store_offset);

	store_offset -= sizeof(long);
	emit_insn(ctx, std, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, store_offset);

	store_offset -= sizeof(long);
	emit_insn(ctx, std, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, store_offset);

	emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_adjust);

	if (bpf_stack_adjust)
		emit_insn(ctx, addid, regmap[BPF_REG_FP], LOONGARCH_GPR_SP, bpf_stack_adjust);

	/*
	 * Program contains calls and tail calls, so REG_TCC need
	 * to be saved across calls.
	 */
	if (seen_tail_call(ctx) && seen_call(ctx))
		move_reg(ctx, TCC_SAVED, REG_TCC);

	ctx->stack_size = stack_adjust;
}

static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call)
{
	int stack_adjust = ctx->stack_size;
	int load_offset;

	load_offset = stack_adjust - sizeof(long);
	emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, load_offset);

	load_offset -= sizeof(long);
	emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, load_offset);

	load_offset -= sizeof(long);
	emit_insn(ctx, ldd, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, load_offset);

	load_offset -= sizeof(long);
	emit_insn(ctx, ldd, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, load_offset);

	load_offset -= sizeof(long);
	emit_insn(ctx, ldd, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, load_offset);

	load_offset -= sizeof(long);
	emit_insn(ctx, ldd, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, load_offset);

	load_offset -= sizeof(long);
	emit_insn(ctx, ldd, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, load_offset);

	load_offset -= sizeof(long);
	emit_insn(ctx, ldd, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, load_offset);

	emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_adjust);

	if (!is_tail_call) {
		/* Set return value */
		move_reg(ctx, LOONGARCH_GPR_A0, regmap[BPF_REG_0]);
		/* Return to the caller */
		emit_insn(ctx, jirl, LOONGARCH_GPR_RA, LOONGARCH_GPR_ZERO, 0);
	} else {
		/*
		 * Call the next bpf prog and skip the first instruction
		 * of TCC initialization.
		 */
		emit_insn(ctx, jirl, LOONGARCH_GPR_T3, LOONGARCH_GPR_ZERO, 1);
	}
}

static void build_epilogue(struct jit_ctx *ctx)
{
	__build_epilogue(ctx, false);
}

bool bpf_jit_supports_kfunc_call(void)
{
	return true;
}

bool bpf_jit_supports_far_kfunc_call(void)
{
	return true;
}

/* initialized on the first pass of build_body() */
static int out_offset = -1;
static int emit_bpf_tail_call(struct jit_ctx *ctx)
{
	int off;
	u8 tcc = tail_call_reg(ctx);
	u8 a1 = LOONGARCH_GPR_A1;
	u8 a2 = LOONGARCH_GPR_A2;
	u8 t1 = LOONGARCH_GPR_T1;
	u8 t2 = LOONGARCH_GPR_T2;
	u8 t3 = LOONGARCH_GPR_T3;
	const int idx0 = ctx->idx;

#define cur_offset (ctx->idx - idx0)
#define jmp_offset (out_offset - (cur_offset))

	/*
	 * a0: &ctx
	 * a1: &array
	 * a2: index
	 *
	 * if (index >= array->map.max_entries)
	 *	 goto out;
	 */
	off = offsetof(struct bpf_array, map.max_entries);
	emit_insn(ctx, ldwu, t1, a1, off);
	/* bgeu $a2, $t1, jmp_offset */
	if (emit_tailcall_jmp(ctx, BPF_JGE, a2, t1, jmp_offset) < 0)
		goto toofar;

	/*
	 * if (--TCC < 0)
	 *	 goto out;
	 */
	emit_insn(ctx, addid, REG_TCC, tcc, -1);
	if (emit_tailcall_jmp(ctx, BPF_JSLT, REG_TCC, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
		goto toofar;

	/*
	 * prog = array->ptrs[index];
	 * if (!prog)
	 *	 goto out;
	 */
	emit_insn(ctx, alsld, t2, a2, a1, 2);
	off = offsetof(struct bpf_array, ptrs);
	emit_insn(ctx, ldd, t2, t2, off);
	/* beq $t2, $zero, jmp_offset */
	if (emit_tailcall_jmp(ctx, BPF_JEQ, t2, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
		goto toofar;

	/* goto *(prog->bpf_func + 4); */
	off = offsetof(struct bpf_prog, bpf_func);
	emit_insn(ctx, ldd, t3, t2, off);
	__build_epilogue(ctx, true);

	/* out: */
	if (out_offset == -1)
		out_offset = cur_offset;
	if (cur_offset != out_offset) {
		pr_err_once("tail_call out_offset = %d, expected %d!\n",
			    cur_offset, out_offset);
		return -1;
	}

	return 0;

toofar:
	pr_info_once("tail_call: jump too far\n");
	return -1;
#undef cur_offset
#undef jmp_offset
}

static void emit_atomic(const struct bpf_insn *insn, struct jit_ctx *ctx)
{
	const u8 t1 = LOONGARCH_GPR_T1;
	const u8 t2 = LOONGARCH_GPR_T2;
	const u8 t3 = LOONGARCH_GPR_T3;
	const u8 r0 = regmap[BPF_REG_0];
	const u8 src = regmap[insn->src_reg];
	const u8 dst = regmap[insn->dst_reg];
	const s16 off = insn->off;
	const s32 imm = insn->imm;
	const bool isdw = BPF_SIZE(insn->code) == BPF_DW;

	move_imm(ctx, t1, off, false);
	emit_insn(ctx, addd, t1, dst, t1);
	move_reg(ctx, t3, src);

	switch (imm) {
	/* lock *(size *)(dst + off) <op>= src */
	case BPF_ADD:
		if (isdw)
			emit_insn(ctx, amaddd, t2, t1, src);
		else
			emit_insn(ctx, amaddw, t2, t1, src);
		break;
	case BPF_AND:
		if (isdw)
			emit_insn(ctx, amandd, t2, t1, src);
		else
			emit_insn(ctx, amandw, t2, t1, src);
		break;
	case BPF_OR:
		if (isdw)
			emit_insn(ctx, amord, t2, t1, src);
		else
			emit_insn(ctx, amorw, t2, t1, src);
		break;
	case BPF_XOR:
		if (isdw)
			emit_insn(ctx, amxord, t2, t1, src);
		else
			emit_insn(ctx, amxorw, t2, t1, src);
		break;
	/* src = atomic_fetch_<op>(dst + off, src) */
	case BPF_ADD | BPF_FETCH:
		if (isdw) {
			emit_insn(ctx, amaddd, src, t1, t3);
		} else {
			emit_insn(ctx, amaddw, src, t1, t3);
			emit_zext_32(ctx, src, true);
		}
		break;
	case BPF_AND | BPF_FETCH:
		if (isdw) {
			emit_insn(ctx, amandd, src, t1, t3);
		} else {
			emit_insn(ctx, amandw, src, t1, t3);
			emit_zext_32(ctx, src, true);
		}
		break;
	case BPF_OR | BPF_FETCH:
		if (isdw) {
			emit_insn(ctx, amord, src, t1, t3);
		} else {
			emit_insn(ctx, amorw, src, t1, t3);
			emit_zext_32(ctx, src, true);
		}
		break;
	case BPF_XOR | BPF_FETCH:
		if (isdw) {
			emit_insn(ctx, amxord, src, t1, t3);
		} else {
			emit_insn(ctx, amxorw, src, t1, t3);
			emit_zext_32(ctx, src, true);
		}
		break;
	/* src = atomic_xchg(dst + off, src); */
	case BPF_XCHG:
		if (isdw) {
			emit_insn(ctx, amswapd, src, t1, t3);
		} else {
			emit_insn(ctx, amswapw, src, t1, t3);
			emit_zext_32(ctx, src, true);
		}
		break;
	/* r0 = atomic_cmpxchg(dst + off, r0, src); */
	case BPF_CMPXCHG:
		move_reg(ctx, t2, r0);
		if (isdw) {
			emit_insn(ctx, lld, r0, t1, 0);
			emit_insn(ctx, bne, t2, r0, 4);
			move_reg(ctx, t3, src);
			emit_insn(ctx, scd, t3, t1, 0);
			emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -4);
		} else {
			emit_insn(ctx, llw, r0, t1, 0);
			emit_zext_32(ctx, t2, true);
			emit_zext_32(ctx, r0, true);
			emit_insn(ctx, bne, t2, r0, 4);
			move_reg(ctx, t3, src);
			emit_insn(ctx, scw, t3, t1, 0);
			emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -6);
			emit_zext_32(ctx, r0, true);
		}
		break;
	}
}

static bool is_signed_bpf_cond(u8 cond)
{
	return cond == BPF_JSGT || cond == BPF_JSLT ||
	       cond == BPF_JSGE || cond == BPF_JSLE;
}

#define BPF_FIXUP_REG_MASK	GENMASK(31, 27)
#define BPF_FIXUP_OFFSET_MASK	GENMASK(26, 0)

bool ex_handler_bpf(const struct exception_table_entry *ex,
		    struct pt_regs *regs)
{
	int dst_reg = FIELD_GET(BPF_FIXUP_REG_MASK, ex->fixup);
	off_t offset = FIELD_GET(BPF_FIXUP_OFFSET_MASK, ex->fixup);

	regs->regs[dst_reg] = 0;
	regs->csr_era = (unsigned long)&ex->fixup - offset;

	return true;
}

/* For accesses to BTF pointers, add an entry to the exception table */
static int add_exception_handler(const struct bpf_insn *insn,
				 struct jit_ctx *ctx,
				 int dst_reg)
{
	unsigned long pc;
	off_t offset;
	struct exception_table_entry *ex;

	if (!ctx->image || !ctx->prog->aux->extable)
		return 0;

	if (BPF_MODE(insn->code) != BPF_PROBE_MEM &&
	    BPF_MODE(insn->code) != BPF_PROBE_MEMSX)
		return 0;

	if (WARN_ON_ONCE(ctx->num_exentries >= ctx->prog->aux->num_exentries))
		return -EINVAL;

	ex = &ctx->prog->aux->extable[ctx->num_exentries];
	pc = (unsigned long)&ctx->image[ctx->idx - 1];

	offset = pc - (long)&ex->insn;
	if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN))
		return -ERANGE;

	ex->insn = offset;

	/*
	 * Since the extable follows the program, the fixup offset is always
	 * negative and limited to BPF_JIT_REGION_SIZE. Store a positive value
	 * to keep things simple, and put the destination register in the upper
	 * bits. We don't need to worry about buildtime or runtime sort
	 * modifying the upper bits because the table is already sorted, and
	 * isn't part of the main exception table.
	 */
	offset = (long)&ex->fixup - (pc + LOONGARCH_INSN_SIZE);
	if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, offset))
		return -ERANGE;

	ex->type = EX_TYPE_BPF;
	ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, offset) | FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg);

	ctx->num_exentries++;

	return 0;
}

static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool extra_pass)
{
	u8 tm = -1;
	u64 func_addr;
	bool func_addr_fixed, sign_extend;
	int i = insn - ctx->prog->insnsi;
	int ret, jmp_offset;
	const u8 code = insn->code;
	const u8 cond = BPF_OP(code);
	const u8 t1 = LOONGARCH_GPR_T1;
	const u8 t2 = LOONGARCH_GPR_T2;
	const u8 src = regmap[insn->src_reg];
	const u8 dst = regmap[insn->dst_reg];
	const s16 off = insn->off;
	const s32 imm = insn->imm;
	const bool is32 = BPF_CLASS(insn->code) == BPF_ALU || BPF_CLASS(insn->code) == BPF_JMP32;

	switch (code) {
	/* dst = src */
	case BPF_ALU | BPF_MOV | BPF_X:
	case BPF_ALU64 | BPF_MOV | BPF_X:
		switch (off) {
		case 0:
			move_reg(ctx, dst, src);
			emit_zext_32(ctx, dst, is32);
			break;
		case 8:
			move_reg(ctx, t1, src);
			emit_insn(ctx, extwb, dst, t1);
			emit_zext_32(ctx, dst, is32);
			break;
		case 16:
			move_reg(ctx, t1, src);
			emit_insn(ctx, extwh, dst, t1);
			emit_zext_32(ctx, dst, is32);
			break;
		case 32:
			emit_insn(ctx, addw, dst, src, LOONGARCH_GPR_ZERO);
			break;
		}
		break;

	/* dst = imm */
	case BPF_ALU | BPF_MOV | BPF_K:
	case BPF_ALU64 | BPF_MOV | BPF_K:
		move_imm(ctx, dst, imm, is32);
		break;

	/* dst = dst + src */
	case BPF_ALU | BPF_ADD | BPF_X:
	case BPF_ALU64 | BPF_ADD | BPF_X:
		emit_insn(ctx, addd, dst, dst, src);
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst + imm */
	case BPF_ALU | BPF_ADD | BPF_K:
	case BPF_ALU64 | BPF_ADD | BPF_K:
		if (is_signed_imm12(imm)) {
			emit_insn(ctx, addid, dst, dst, imm);
		} else {
			move_imm(ctx, t1, imm, is32);
			emit_insn(ctx, addd, dst, dst, t1);
		}
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst - src */
	case BPF_ALU | BPF_SUB | BPF_X:
	case BPF_ALU64 | BPF_SUB | BPF_X:
		emit_insn(ctx, subd, dst, dst, src);
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst - imm */
	case BPF_ALU | BPF_SUB | BPF_K:
	case BPF_ALU64 | BPF_SUB | BPF_K:
		if (is_signed_imm12(-imm)) {
			emit_insn(ctx, addid, dst, dst, -imm);
		} else {
			move_imm(ctx, t1, imm, is32);
			emit_insn(ctx, subd, dst, dst, t1);
		}
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst * src */
	case BPF_ALU | BPF_MUL | BPF_X:
	case BPF_ALU64 | BPF_MUL | BPF_X:
		emit_insn(ctx, muld, dst, dst, src);
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst * imm */
	case BPF_ALU | BPF_MUL | BPF_K:
	case BPF_ALU64 | BPF_MUL | BPF_K:
		move_imm(ctx, t1, imm, is32);
		emit_insn(ctx, muld, dst, dst, t1);
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst / src */
	case BPF_ALU | BPF_DIV | BPF_X:
	case BPF_ALU64 | BPF_DIV | BPF_X:
		if (!off) {
			emit_zext_32(ctx, dst, is32);
			move_reg(ctx, t1, src);
			emit_zext_32(ctx, t1, is32);
			emit_insn(ctx, divdu, dst, dst, t1);
			emit_zext_32(ctx, dst, is32);
		} else {
			emit_sext_32(ctx, dst, is32);
			move_reg(ctx, t1, src);
			emit_sext_32(ctx, t1, is32);
			emit_insn(ctx, divd, dst, dst, t1);
			emit_sext_32(ctx, dst, is32);
		}
		break;

	/* dst = dst / imm */
	case BPF_ALU | BPF_DIV | BPF_K:
	case BPF_ALU64 | BPF_DIV | BPF_K:
		if (!off) {
			move_imm(ctx, t1, imm, is32);
			emit_zext_32(ctx, dst, is32);
			emit_insn(ctx, divdu, dst, dst, t1);
			emit_zext_32(ctx, dst, is32);
		} else {
			move_imm(ctx, t1, imm, false);
			emit_sext_32(ctx, t1, is32);
			emit_sext_32(ctx, dst, is32);
			emit_insn(ctx, divd, dst, dst, t1);
			emit_sext_32(ctx, dst, is32);
		}
		break;

	/* dst = dst % src */
	case BPF_ALU | BPF_MOD | BPF_X:
	case BPF_ALU64 | BPF_MOD | BPF_X:
		if (!off) {
			emit_zext_32(ctx, dst, is32);
			move_reg(ctx, t1, src);
			emit_zext_32(ctx, t1, is32);
			emit_insn(ctx, moddu, dst, dst, t1);
			emit_zext_32(ctx, dst, is32);
		} else {
			emit_sext_32(ctx, dst, is32);
			move_reg(ctx, t1, src);
			emit_sext_32(ctx, t1, is32);
			emit_insn(ctx, modd, dst, dst, t1);
			emit_sext_32(ctx, dst, is32);
		}
		break;

	/* dst = dst % imm */
	case BPF_ALU | BPF_MOD | BPF_K:
	case BPF_ALU64 | BPF_MOD | BPF_K:
		if (!off) {
			move_imm(ctx, t1, imm, is32);
			emit_zext_32(ctx, dst, is32);
			emit_insn(ctx, moddu, dst, dst, t1);
			emit_zext_32(ctx, dst, is32);
		} else {
			move_imm(ctx, t1, imm, false);
			emit_sext_32(ctx, t1, is32);
			emit_sext_32(ctx, dst, is32);
			emit_insn(ctx, modd, dst, dst, t1);
			emit_sext_32(ctx, dst, is32);
		}
		break;

	/* dst = -dst */
	case BPF_ALU | BPF_NEG:
	case BPF_ALU64 | BPF_NEG:
		move_imm(ctx, t1, imm, is32);
		emit_insn(ctx, subd, dst, LOONGARCH_GPR_ZERO, dst);
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst & src */
	case BPF_ALU | BPF_AND | BPF_X:
	case BPF_ALU64 | BPF_AND | BPF_X:
		emit_insn(ctx, and, dst, dst, src);
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst & imm */
	case BPF_ALU | BPF_AND | BPF_K:
	case BPF_ALU64 | BPF_AND | BPF_K:
		if (is_unsigned_imm12(imm)) {
			emit_insn(ctx, andi, dst, dst, imm);
		} else {
			move_imm(ctx, t1, imm, is32);
			emit_insn(ctx, and, dst, dst, t1);
		}
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst | src */
	case BPF_ALU | BPF_OR | BPF_X:
	case BPF_ALU64 | BPF_OR | BPF_X:
		emit_insn(ctx, or, dst, dst, src);
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst | imm */
	case BPF_ALU | BPF_OR | BPF_K:
	case BPF_ALU64 | BPF_OR | BPF_K:
		if (is_unsigned_imm12(imm)) {
			emit_insn(ctx, ori, dst, dst, imm);
		} else {
			move_imm(ctx, t1, imm, is32);
			emit_insn(ctx, or, dst, dst, t1);
		}
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst ^ src */
	case BPF_ALU | BPF_XOR | BPF_X:
	case BPF_ALU64 | BPF_XOR | BPF_X:
		emit_insn(ctx, xor, dst, dst, src);
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst ^ imm */
	case BPF_ALU | BPF_XOR | BPF_K:
	case BPF_ALU64 | BPF_XOR | BPF_K:
		if (is_unsigned_imm12(imm)) {
			emit_insn(ctx, xori, dst, dst, imm);
		} else {
			move_imm(ctx, t1, imm, is32);
			emit_insn(ctx, xor, dst, dst, t1);
		}
		emit_zext_32(ctx, dst, is32);
		break;

	/* dst = dst << src (logical) */
	case BPF_ALU | BPF_LSH | BPF_X:
		emit_insn(ctx, sllw, dst, dst, src);
		emit_zext_32(ctx, dst, is32);
		break;

	case BPF_ALU64 | BPF_LSH | BPF_X:
		emit_insn(ctx, slld, dst, dst, src);
		break;

	/* dst = dst << imm (logical) */
	case BPF_ALU | BPF_LSH | BPF_K:
		emit_insn(ctx, slliw, dst, dst, imm);
		emit_zext_32(ctx, dst, is32);
		break;

	case BPF_ALU64 | BPF_LSH | BPF_K:
		emit_insn(ctx, sllid, dst, dst, imm);
		break;

	/* dst = dst >> src (logical) */
	case BPF_ALU | BPF_RSH | BPF_X:
		emit_insn(ctx, srlw, dst, dst, src);
		emit_zext_32(ctx, dst, is32);
		break;

	case BPF_ALU64 | BPF_RSH | BPF_X:
		emit_insn(ctx, srld, dst, dst, src);
		break;

	/* dst = dst >> imm (logical) */
	case BPF_ALU | BPF_RSH | BPF_K:
		emit_insn(ctx, srliw, dst, dst, imm);
		emit_zext_32(ctx, dst, is32);
		break;

	case BPF_ALU64 | BPF_RSH | BPF_K:
		emit_insn(ctx, srlid, dst, dst, imm);
		break;

	/* dst = dst >> src (arithmetic) */
	case BPF_ALU | BPF_ARSH | BPF_X:
		emit_insn(ctx, sraw, dst, dst, src);
		emit_zext_32(ctx, dst, is32);
		break;

	case BPF_ALU64 | BPF_ARSH | BPF_X:
		emit_insn(ctx, srad, dst, dst, src);
		break;

	/* dst = dst >> imm (arithmetic) */
	case BPF_ALU | BPF_ARSH | BPF_K:
		emit_insn(ctx, sraiw, dst, dst, imm);
		emit_zext_32(ctx, dst, is32);
		break;

	case BPF_ALU64 | BPF_ARSH | BPF_K:
		emit_insn(ctx, sraid, dst, dst, imm);
		break;

	/* dst = BSWAP##imm(dst) */
	case BPF_ALU | BPF_END | BPF_FROM_LE:
		switch (imm) {
		case 16:
			/* zero-extend 16 bits into 64 bits */
			emit_insn(ctx, bstrpickd, dst, dst, 15, 0);
			break;
		case 32:
			/* zero-extend 32 bits into 64 bits */
			emit_zext_32(ctx, dst, is32);
			break;
		case 64:
			/* do nothing */
			break;
		}
		break;

	case BPF_ALU | BPF_END | BPF_FROM_BE:
	case BPF_ALU64 | BPF_END | BPF_FROM_LE:
		switch (imm) {
		case 16:
			emit_insn(ctx, revb2h, dst, dst);
			/* zero-extend 16 bits into 64 bits */
			emit_insn(ctx, bstrpickd, dst, dst, 15, 0);
			break;
		case 32:
			emit_insn(ctx, revb2w, dst, dst);
			/* clear the upper 32 bits */
			emit_zext_32(ctx, dst, true);
			break;
		case 64:
			emit_insn(ctx, revbd, dst, dst);
			break;
		}
		break;

	/* PC += off if dst cond src */
	case BPF_JMP | BPF_JEQ | BPF_X:
	case BPF_JMP | BPF_JNE | BPF_X:
	case BPF_JMP | BPF_JGT | BPF_X:
	case BPF_JMP | BPF_JGE | BPF_X:
	case BPF_JMP | BPF_JLT | BPF_X:
	case BPF_JMP | BPF_JLE | BPF_X:
	case BPF_JMP | BPF_JSGT | BPF_X:
	case BPF_JMP | BPF_JSGE | BPF_X:
	case BPF_JMP | BPF_JSLT | BPF_X:
	case BPF_JMP | BPF_JSLE | BPF_X:
	case BPF_JMP32 | BPF_JEQ | BPF_X:
	case BPF_JMP32 | BPF_JNE | BPF_X:
	case BPF_JMP32 | BPF_JGT | BPF_X:
	case BPF_JMP32 | BPF_JGE | BPF_X:
	case BPF_JMP32 | BPF_JLT | BPF_X:
	case BPF_JMP32 | BPF_JLE | BPF_X:
	case BPF_JMP32 | BPF_JSGT | BPF_X:
	case BPF_JMP32 | BPF_JSGE | BPF_X:
	case BPF_JMP32 | BPF_JSLT | BPF_X:
	case BPF_JMP32 | BPF_JSLE | BPF_X:
		jmp_offset = bpf2la_offset(i, off, ctx);
		move_reg(ctx, t1, dst);
		move_reg(ctx, t2, src);
		if (is_signed_bpf_cond(BPF_OP(code))) {
			emit_sext_32(ctx, t1, is32);
			emit_sext_32(ctx, t2, is32);
		} else {
			emit_zext_32(ctx, t1, is32);
			emit_zext_32(ctx, t2, is32);
		}
		if (emit_cond_jmp(ctx, cond, t1, t2, jmp_offset) < 0)
			goto toofar;
		break;

	/* PC += off if dst cond imm */
	case BPF_JMP | BPF_JEQ | BPF_K:
	case BPF_JMP | BPF_JNE | BPF_K:
	case BPF_JMP | BPF_JGT | BPF_K:
	case BPF_JMP | BPF_JGE | BPF_K:
	case BPF_JMP | BPF_JLT | BPF_K:
	case BPF_JMP | BPF_JLE | BPF_K:
	case BPF_JMP | BPF_JSGT | BPF_K:
	case BPF_JMP | BPF_JSGE | BPF_K:
	case BPF_JMP | BPF_JSLT | BPF_K:
	case BPF_JMP | BPF_JSLE | BPF_K:
	case BPF_JMP32 | BPF_JEQ | BPF_K:
	case BPF_JMP32 | BPF_JNE | BPF_K:
	case BPF_JMP32 | BPF_JGT | BPF_K:
	case BPF_JMP32 | BPF_JGE | BPF_K:
	case BPF_JMP32 | BPF_JLT | BPF_K:
	case BPF_JMP32 | BPF_JLE | BPF_K:
	case BPF_JMP32 | BPF_JSGT | BPF_K:
	case BPF_JMP32 | BPF_JSGE | BPF_K:
	case BPF_JMP32 | BPF_JSLT | BPF_K:
	case BPF_JMP32 | BPF_JSLE | BPF_K:
		jmp_offset = bpf2la_offset(i, off, ctx);
		if (imm) {
			move_imm(ctx, t1, imm, false);
			tm = t1;
		} else {
			/* If imm is 0, simply use zero register. */
			tm = LOONGARCH_GPR_ZERO;
		}
		move_reg(ctx, t2, dst);
		if (is_signed_bpf_cond(BPF_OP(code))) {
			emit_sext_32(ctx, tm, is32);
			emit_sext_32(ctx, t2, is32);
		} else {
			emit_zext_32(ctx, tm, is32);
			emit_zext_32(ctx, t2, is32);
		}
		if (emit_cond_jmp(ctx, cond, t2, tm, jmp_offset) < 0)
			goto toofar;
		break;

	/* PC += off if dst & src */
	case BPF_JMP | BPF_JSET | BPF_X:
	case BPF_JMP32 | BPF_JSET | BPF_X:
		jmp_offset = bpf2la_offset(i, off, ctx);
		emit_insn(ctx, and, t1, dst, src);
		emit_zext_32(ctx, t1, is32);
		if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
			goto toofar;
		break;

	/* PC += off if dst & imm */
	case BPF_JMP | BPF_JSET | BPF_K:
	case BPF_JMP32 | BPF_JSET | BPF_K:
		jmp_offset = bpf2la_offset(i, off, ctx);
		move_imm(ctx, t1, imm, is32);
		emit_insn(ctx, and, t1, dst, t1);
		emit_zext_32(ctx, t1, is32);
		if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
			goto toofar;
		break;

	/* PC += off */
	case BPF_JMP | BPF_JA:
	case BPF_JMP32 | BPF_JA:
		if (BPF_CLASS(code) == BPF_JMP)
			jmp_offset = bpf2la_offset(i, off, ctx);
		else
			jmp_offset = bpf2la_offset(i, imm, ctx);
		if (emit_uncond_jmp(ctx, jmp_offset) < 0)
			goto toofar;
		break;

	/* function call */
	case BPF_JMP | BPF_CALL:
		mark_call(ctx);
		ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass,
					    &func_addr, &func_addr_fixed);
		if (ret < 0)
			return ret;

		move_addr(ctx, t1, func_addr);
		emit_insn(ctx, jirl, t1, LOONGARCH_GPR_RA, 0);
		move_reg(ctx, regmap[BPF_REG_0], LOONGARCH_GPR_A0);
		break;

	/* tail call */
	case BPF_JMP | BPF_TAIL_CALL:
		mark_tail_call(ctx);
		if (emit_bpf_tail_call(ctx) < 0)
			return -EINVAL;
		break;

	/* function return */
	case BPF_JMP | BPF_EXIT:
		if (i == ctx->prog->len - 1)
			break;

		jmp_offset = epilogue_offset(ctx);
		if (emit_uncond_jmp(ctx, jmp_offset) < 0)
			goto toofar;
		break;

	/* dst = imm64 */
	case BPF_LD | BPF_IMM | BPF_DW:
	{
		const u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm;

		move_imm(ctx, dst, imm64, is32);
		return 1;
	}

	/* dst = *(size *)(src + off) */
	case BPF_LDX | BPF_MEM | BPF_B:
	case BPF_LDX | BPF_MEM | BPF_H:
	case BPF_LDX | BPF_MEM | BPF_W:
	case BPF_LDX | BPF_MEM | BPF_DW:
	case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
	case BPF_LDX | BPF_PROBE_MEM | BPF_W:
	case BPF_LDX | BPF_PROBE_MEM | BPF_H:
	case BPF_LDX | BPF_PROBE_MEM | BPF_B:
	/* dst_reg = (s64)*(signed size *)(src_reg + off) */
	case BPF_LDX | BPF_MEMSX | BPF_B:
	case BPF_LDX | BPF_MEMSX | BPF_H:
	case BPF_LDX | BPF_MEMSX | BPF_W:
	case BPF_LDX | BPF_PROBE_MEMSX | BPF_B:
	case BPF_LDX | BPF_PROBE_MEMSX | BPF_H:
	case BPF_LDX | BPF_PROBE_MEMSX | BPF_W:
		sign_extend = BPF_MODE(insn->code) == BPF_MEMSX ||
			      BPF_MODE(insn->code) == BPF_PROBE_MEMSX;
		switch (BPF_SIZE(code)) {
		case BPF_B:
			if (is_signed_imm12(off)) {
				if (sign_extend)
					emit_insn(ctx, ldb, dst, src, off);
				else
					emit_insn(ctx, ldbu, dst, src, off);
			} else {
				move_imm(ctx, t1, off, is32);
				if (sign_extend)
					emit_insn(ctx, ldxb, dst, src, t1);
				else
					emit_insn(ctx, ldxbu, dst, src, t1);
			}
			break;
		case BPF_H:
			if (is_signed_imm12(off)) {
				if (sign_extend)
					emit_insn(ctx, ldh, dst, src, off);
				else
					emit_insn(ctx, ldhu, dst, src, off);
			} else {
				move_imm(ctx, t1, off, is32);
				if (sign_extend)
					emit_insn(ctx, ldxh, dst, src, t1);
				else
					emit_insn(ctx, ldxhu, dst, src, t1);
			}
			break;
		case BPF_W:
			if (is_signed_imm12(off)) {
				if (sign_extend)
					emit_insn(ctx, ldw, dst, src, off);
				else
					emit_insn(ctx, ldwu, dst, src, off);
			} else {
				move_imm(ctx, t1, off, is32);
				if (sign_extend)
					emit_insn(ctx, ldxw, dst, src, t1);
				else
					emit_insn(ctx, ldxwu, dst, src, t1);
			}
			break;
		case BPF_DW:
			move_imm(ctx, t1, off, is32);
			emit_insn(ctx, ldxd, dst, src, t1);
			break;
		}

		ret = add_exception_handler(insn, ctx, dst);
		if (ret)
			return ret;
		break;

	/* *(size *)(dst + off) = imm */
	case BPF_ST | BPF_MEM | BPF_B:
	case BPF_ST | BPF_MEM | BPF_H:
	case BPF_ST | BPF_MEM | BPF_W:
	case BPF_ST | BPF_MEM | BPF_DW:
		switch (BPF_SIZE(code)) {
		case BPF_B:
			move_imm(ctx, t1, imm, is32);
			if (is_signed_imm12(off)) {
				emit_insn(ctx, stb, t1, dst, off);
			} else {
				move_imm(ctx, t2, off, is32);
				emit_insn(ctx, stxb, t1, dst, t2);
			}
			break;
		case BPF_H:
			move_imm(ctx, t1, imm, is32);
			if (is_signed_imm12(off)) {
				emit_insn(ctx, sth, t1, dst, off);
			} else {
				move_imm(ctx, t2, off, is32);
				emit_insn(ctx, stxh, t1, dst, t2);
			}
			break;
		case BPF_W:
			move_imm(ctx, t1, imm, is32);
			if (is_signed_imm12(off)) {
				emit_insn(ctx, stw, t1, dst, off);
			} else if (is_signed_imm14(off)) {
				emit_insn(ctx, stptrw, t1, dst, off);
			} else {
				move_imm(ctx, t2, off, is32);
				emit_insn(ctx, stxw, t1, dst, t2);
			}
			break;
		case BPF_DW:
			move_imm(ctx, t1, imm, is32);
			if (is_signed_imm12(off)) {
				emit_insn(ctx, std, t1, dst, off);
			} else if (is_signed_imm14(off)) {
				emit_insn(ctx, stptrd, t1, dst, off);
			} else {
				move_imm(ctx, t2, off, is32);
				emit_insn(ctx, stxd, t1, dst, t2);
			}
			break;
		}
		break;

	/* *(size *)(dst + off) = src */
	case BPF_STX | BPF_MEM | BPF_B:
	case BPF_STX | BPF_MEM | BPF_H:
	case BPF_STX | BPF_MEM | BPF_W:
	case BPF_STX | BPF_MEM | BPF_DW:
		switch (BPF_SIZE(code)) {
		case BPF_B:
			if (is_signed_imm12(off)) {
				emit_insn(ctx, stb, src, dst, off);
			} else {
				move_imm(ctx, t1, off, is32);
				emit_insn(ctx, stxb, src, dst, t1);
			}
			break;
		case BPF_H:
			if (is_signed_imm12(off)) {
				emit_insn(ctx, sth, src, dst, off);
			} else {
				move_imm(ctx, t1, off, is32);
				emit_insn(ctx, stxh, src, dst, t1);
			}
			break;
		case BPF_W:
			if (is_signed_imm12(off)) {
				emit_insn(ctx, stw, src, dst, off);
			} else if (is_signed_imm14(off)) {
				emit_insn(ctx, stptrw, src, dst, off);
			} else {
				move_imm(ctx, t1, off, is32);
				emit_insn(ctx, stxw, src, dst, t1);
			}
			break;
		case BPF_DW:
			if (is_signed_imm12(off)) {
				emit_insn(ctx, std, src, dst, off);
			} else if (is_signed_imm14(off)) {
				emit_insn(ctx, stptrd, src, dst, off);
			} else {
				move_imm(ctx, t1, off, is32);
				emit_insn(ctx, stxd, src, dst, t1);
			}
			break;
		}
		break;

	case BPF_STX | BPF_ATOMIC | BPF_W:
	case BPF_STX | BPF_ATOMIC | BPF_DW:
		emit_atomic(insn, ctx);
		break;

	/* Speculation barrier */
	case BPF_ST | BPF_NOSPEC:
		break;

	default:
		pr_err("bpf_jit: unknown opcode %02x\n", code);
		return -EINVAL;
	}

	return 0;

toofar:
	pr_info_once("bpf_jit: opcode %02x, jump too far\n", code);
	return -E2BIG;
}

static int build_body(struct jit_ctx *ctx, bool extra_pass)
{
	int i;
	const struct bpf_prog *prog = ctx->prog;

	for (i = 0; i < prog->len; i++) {
		const struct bpf_insn *insn = &prog->insnsi[i];
		int ret;

		if (ctx->image == NULL)
			ctx->offset[i] = ctx->idx;

		ret = build_insn(insn, ctx, extra_pass);
		if (ret > 0) {
			i++;
			if (ctx->image == NULL)
				ctx->offset[i] = ctx->idx;
			continue;
		}
		if (ret)
			return ret;
	}

	if (ctx->image == NULL)
		ctx->offset[i] = ctx->idx;

	return 0;
}

/* Fill space with break instructions */
static void jit_fill_hole(void *area, unsigned int size)
{
	u32 *ptr;

	/* We are guaranteed to have aligned memory */
	for (ptr = area; size >= sizeof(u32); size -= sizeof(u32))
		*ptr++ = INSN_BREAK;
}

static int validate_code(struct jit_ctx *ctx)
{
	int i;
	union loongarch_instruction insn;

	for (i = 0; i < ctx->idx; i++) {
		insn = ctx->image[i];
		/* Check INSN_BREAK */
		if (insn.word == INSN_BREAK)
			return -1;
	}

	if (WARN_ON_ONCE(ctx->num_exentries != ctx->prog->aux->num_exentries))
		return -1;

	return 0;
}

struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
	bool tmp_blinded = false, extra_pass = false;
	u8 *image_ptr;
	int image_size, prog_size, extable_size;
	struct jit_ctx ctx;
	struct jit_data *jit_data;
	struct bpf_binary_header *header;
	struct bpf_prog *tmp, *orig_prog = prog;

	/*
	 * If BPF JIT was not enabled then we must fall back to
	 * the interpreter.
	 */
	if (!prog->jit_requested)
		return orig_prog;

	tmp = bpf_jit_blind_constants(prog);
	/*
	 * If blinding was requested and we failed during blinding,
	 * we must fall back to the interpreter. Otherwise, we save
	 * the new JITed code.
	 */
	if (IS_ERR(tmp))
		return orig_prog;

	if (tmp != prog) {
		tmp_blinded = true;
		prog = tmp;
	}

	jit_data = prog->aux->jit_data;
	if (!jit_data) {
		jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
		if (!jit_data) {
			prog = orig_prog;
			goto out;
		}
		prog->aux->jit_data = jit_data;
	}
	if (jit_data->ctx.offset) {
		ctx = jit_data->ctx;
		image_ptr = jit_data->image;
		header = jit_data->header;
		extra_pass = true;
		prog_size = sizeof(u32) * ctx.idx;
		goto skip_init_ctx;
	}

	memset(&ctx, 0, sizeof(ctx));
	ctx.prog = prog;

	ctx.offset = kvcalloc(prog->len + 1, sizeof(u32), GFP_KERNEL);
	if (ctx.offset == NULL) {
		prog = orig_prog;
		goto out_offset;
	}

	/* 1. Initial fake pass to compute ctx->idx and set ctx->flags */
	build_prologue(&ctx);
	if (build_body(&ctx, extra_pass)) {
		prog = orig_prog;
		goto out_offset;
	}
	ctx.epilogue_offset = ctx.idx;
	build_epilogue(&ctx);

	extable_size = prog->aux->num_exentries * sizeof(struct exception_table_entry);

	/* Now we know the actual image size.
	 * As each LoongArch instruction is of length 32bit,
	 * we are translating number of JITed intructions into
	 * the size required to store these JITed code.
	 */
	prog_size = sizeof(u32) * ctx.idx;
	image_size = prog_size + extable_size;
	/* Now we know the size of the structure to make */
	header = bpf_jit_binary_alloc(image_size, &image_ptr,
				      sizeof(u32), jit_fill_hole);
	if (header == NULL) {
		prog = orig_prog;
		goto out_offset;
	}

	/* 2. Now, the actual pass to generate final JIT code */
	ctx.image = (union loongarch_instruction *)image_ptr;
	if (extable_size)
		prog->aux->extable = (void *)image_ptr + prog_size;

skip_init_ctx:
	ctx.idx = 0;
	ctx.num_exentries = 0;

	build_prologue(&ctx);
	if (build_body(&ctx, extra_pass)) {
		bpf_jit_binary_free(header);
		prog = orig_prog;
		goto out_offset;
	}
	build_epilogue(&ctx);

	/* 3. Extra pass to validate JITed code */
	if (validate_code(&ctx)) {
		bpf_jit_binary_free(header);
		prog = orig_prog;
		goto out_offset;
	}

	/* And we're done */
	if (bpf_jit_enable > 1)
		bpf_jit_dump(prog->len, prog_size, 2, ctx.image);

	/* Update the icache */
	flush_icache_range((unsigned long)header, (unsigned long)(ctx.image + ctx.idx));

	if (!prog->is_func || extra_pass) {
		if (extra_pass && ctx.idx != jit_data->ctx.idx) {
			pr_err_once("multi-func JIT bug %d != %d\n",
				    ctx.idx, jit_data->ctx.idx);
			bpf_jit_binary_free(header);
			prog->bpf_func = NULL;
			prog->jited = 0;
			prog->jited_len = 0;
			goto out_offset;
		}
		bpf_jit_binary_lock_ro(header);
	} else {
		jit_data->ctx = ctx;
		jit_data->image = image_ptr;
		jit_data->header = header;
	}
	prog->jited = 1;
	prog->jited_len = prog_size;
	prog->bpf_func = (void *)ctx.image;

	if (!prog->is_func || extra_pass) {
		int i;

		/* offset[prog->len] is the size of program */
		for (i = 0; i <= prog->len; i++)
			ctx.offset[i] *= LOONGARCH_INSN_SIZE;
		bpf_prog_fill_jited_linfo(prog, ctx.offset + 1);

out_offset:
		kvfree(ctx.offset);
		kfree(jit_data);
		prog->aux->jit_data = NULL;
	}

out:
	if (tmp_blinded)
		bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog);

	out_offset = -1;

	return prog;
}

/* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */
bool bpf_jit_supports_subprog_tailcalls(void)
{
	return true;
}