xref: /linux/arch/arm64/lib/insn.c (revision 6f7e6393d1ce636bb7ec77a7fe7b77458fddf701)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2013 Huawei Ltd.
4  * Author: Jiang Liu <liuj97@gmail.com>
5  *
6  * Copyright (C) 2014-2016 Zi Shen Lim <zlim.lnx@gmail.com>
7  */
8 #include <linux/bitfield.h>
9 #include <linux/bitops.h>
10 #include <linux/bug.h>
11 #include <linux/printk.h>
12 #include <linux/sizes.h>
13 #include <linux/types.h>
14 
15 #include <asm/debug-monitors.h>
16 #include <asm/errno.h>
17 #include <asm/insn.h>
18 #include <asm/kprobes.h>
19 
20 #define AARCH64_INSN_SF_BIT	BIT(31)
21 #define AARCH64_INSN_N_BIT	BIT(22)
22 #define AARCH64_INSN_LSL_12	BIT(22)
23 
24 static int __kprobes aarch64_get_imm_shift_mask(enum aarch64_insn_imm_type type,
25 						u32 *maskp, int *shiftp)
26 {
27 	u32 mask;
28 	int shift;
29 
30 	switch (type) {
31 	case AARCH64_INSN_IMM_26:
32 		mask = BIT(26) - 1;
33 		shift = 0;
34 		break;
35 	case AARCH64_INSN_IMM_19:
36 		mask = BIT(19) - 1;
37 		shift = 5;
38 		break;
39 	case AARCH64_INSN_IMM_16:
40 		mask = BIT(16) - 1;
41 		shift = 5;
42 		break;
43 	case AARCH64_INSN_IMM_14:
44 		mask = BIT(14) - 1;
45 		shift = 5;
46 		break;
47 	case AARCH64_INSN_IMM_12:
48 		mask = BIT(12) - 1;
49 		shift = 10;
50 		break;
51 	case AARCH64_INSN_IMM_9:
52 		mask = BIT(9) - 1;
53 		shift = 12;
54 		break;
55 	case AARCH64_INSN_IMM_7:
56 		mask = BIT(7) - 1;
57 		shift = 15;
58 		break;
59 	case AARCH64_INSN_IMM_6:
60 	case AARCH64_INSN_IMM_S:
61 		mask = BIT(6) - 1;
62 		shift = 10;
63 		break;
64 	case AARCH64_INSN_IMM_R:
65 		mask = BIT(6) - 1;
66 		shift = 16;
67 		break;
68 	case AARCH64_INSN_IMM_N:
69 		mask = 1;
70 		shift = 22;
71 		break;
72 	default:
73 		return -EINVAL;
74 	}
75 
76 	*maskp = mask;
77 	*shiftp = shift;
78 
79 	return 0;
80 }
81 
82 #define ADR_IMM_HILOSPLIT	2
83 #define ADR_IMM_SIZE		SZ_2M
84 #define ADR_IMM_LOMASK		((1 << ADR_IMM_HILOSPLIT) - 1)
85 #define ADR_IMM_HIMASK		((ADR_IMM_SIZE >> ADR_IMM_HILOSPLIT) - 1)
86 #define ADR_IMM_LOSHIFT		29
87 #define ADR_IMM_HISHIFT		5
88 
89 u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn)
90 {
91 	u32 immlo, immhi, mask;
92 	int shift;
93 
94 	switch (type) {
95 	case AARCH64_INSN_IMM_ADR:
96 		shift = 0;
97 		immlo = (insn >> ADR_IMM_LOSHIFT) & ADR_IMM_LOMASK;
98 		immhi = (insn >> ADR_IMM_HISHIFT) & ADR_IMM_HIMASK;
99 		insn = (immhi << ADR_IMM_HILOSPLIT) | immlo;
100 		mask = ADR_IMM_SIZE - 1;
101 		break;
102 	default:
103 		if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
104 			pr_err("%s: unknown immediate encoding %d\n", __func__,
105 			       type);
106 			return 0;
107 		}
108 	}
109 
110 	return (insn >> shift) & mask;
111 }
112 
113 u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
114 				  u32 insn, u64 imm)
115 {
116 	u32 immlo, immhi, mask;
117 	int shift;
118 
119 	if (insn == AARCH64_BREAK_FAULT)
120 		return AARCH64_BREAK_FAULT;
121 
122 	switch (type) {
123 	case AARCH64_INSN_IMM_ADR:
124 		shift = 0;
125 		immlo = (imm & ADR_IMM_LOMASK) << ADR_IMM_LOSHIFT;
126 		imm >>= ADR_IMM_HILOSPLIT;
127 		immhi = (imm & ADR_IMM_HIMASK) << ADR_IMM_HISHIFT;
128 		imm = immlo | immhi;
129 		mask = ((ADR_IMM_LOMASK << ADR_IMM_LOSHIFT) |
130 			(ADR_IMM_HIMASK << ADR_IMM_HISHIFT));
131 		break;
132 	default:
133 		if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
134 			pr_err("%s: unknown immediate encoding %d\n", __func__,
135 			       type);
136 			return AARCH64_BREAK_FAULT;
137 		}
138 	}
139 
140 	/* Update the immediate field. */
141 	insn &= ~(mask << shift);
142 	insn |= (imm & mask) << shift;
143 
144 	return insn;
145 }
146 
147 u32 aarch64_insn_decode_register(enum aarch64_insn_register_type type,
148 					u32 insn)
149 {
150 	int shift;
151 
152 	switch (type) {
153 	case AARCH64_INSN_REGTYPE_RT:
154 	case AARCH64_INSN_REGTYPE_RD:
155 		shift = 0;
156 		break;
157 	case AARCH64_INSN_REGTYPE_RN:
158 		shift = 5;
159 		break;
160 	case AARCH64_INSN_REGTYPE_RT2:
161 	case AARCH64_INSN_REGTYPE_RA:
162 		shift = 10;
163 		break;
164 	case AARCH64_INSN_REGTYPE_RM:
165 		shift = 16;
166 		break;
167 	default:
168 		pr_err("%s: unknown register type encoding %d\n", __func__,
169 		       type);
170 		return 0;
171 	}
172 
173 	return (insn >> shift) & GENMASK(4, 0);
174 }
175 
176 static u32 aarch64_insn_encode_register(enum aarch64_insn_register_type type,
177 					u32 insn,
178 					enum aarch64_insn_register reg)
179 {
180 	int shift;
181 
182 	if (insn == AARCH64_BREAK_FAULT)
183 		return AARCH64_BREAK_FAULT;
184 
185 	if (reg < AARCH64_INSN_REG_0 || reg > AARCH64_INSN_REG_SP) {
186 		pr_err("%s: unknown register encoding %d\n", __func__, reg);
187 		return AARCH64_BREAK_FAULT;
188 	}
189 
190 	switch (type) {
191 	case AARCH64_INSN_REGTYPE_RT:
192 	case AARCH64_INSN_REGTYPE_RD:
193 		shift = 0;
194 		break;
195 	case AARCH64_INSN_REGTYPE_RN:
196 		shift = 5;
197 		break;
198 	case AARCH64_INSN_REGTYPE_RT2:
199 	case AARCH64_INSN_REGTYPE_RA:
200 		shift = 10;
201 		break;
202 	case AARCH64_INSN_REGTYPE_RM:
203 	case AARCH64_INSN_REGTYPE_RS:
204 		shift = 16;
205 		break;
206 	default:
207 		pr_err("%s: unknown register type encoding %d\n", __func__,
208 		       type);
209 		return AARCH64_BREAK_FAULT;
210 	}
211 
212 	insn &= ~(GENMASK(4, 0) << shift);
213 	insn |= reg << shift;
214 
215 	return insn;
216 }
217 
218 static const u32 aarch64_insn_ldst_size[] = {
219 	[AARCH64_INSN_SIZE_8] = 0,
220 	[AARCH64_INSN_SIZE_16] = 1,
221 	[AARCH64_INSN_SIZE_32] = 2,
222 	[AARCH64_INSN_SIZE_64] = 3,
223 };
224 
225 static u32 aarch64_insn_encode_ldst_size(enum aarch64_insn_size_type type,
226 					 u32 insn)
227 {
228 	u32 size;
229 
230 	if (type < AARCH64_INSN_SIZE_8 || type > AARCH64_INSN_SIZE_64) {
231 		pr_err("%s: unknown size encoding %d\n", __func__, type);
232 		return AARCH64_BREAK_FAULT;
233 	}
234 
235 	size = aarch64_insn_ldst_size[type];
236 	insn &= ~GENMASK(31, 30);
237 	insn |= size << 30;
238 
239 	return insn;
240 }
241 
242 static inline long label_imm_common(unsigned long pc, unsigned long addr,
243 				     long range)
244 {
245 	long offset;
246 
247 	if ((pc & 0x3) || (addr & 0x3)) {
248 		pr_err("%s: A64 instructions must be word aligned\n", __func__);
249 		return range;
250 	}
251 
252 	offset = ((long)addr - (long)pc);
253 
254 	if (offset < -range || offset >= range) {
255 		pr_err("%s: offset out of range\n", __func__);
256 		return range;
257 	}
258 
259 	return offset;
260 }
261 
262 u32 __kprobes aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr,
263 					  enum aarch64_insn_branch_type type)
264 {
265 	u32 insn;
266 	long offset;
267 
268 	/*
269 	 * B/BL support [-128M, 128M) offset
270 	 * ARM64 virtual address arrangement guarantees all kernel and module
271 	 * texts are within +/-128M.
272 	 */
273 	offset = label_imm_common(pc, addr, SZ_128M);
274 	if (offset >= SZ_128M)
275 		return AARCH64_BREAK_FAULT;
276 
277 	switch (type) {
278 	case AARCH64_INSN_BRANCH_LINK:
279 		insn = aarch64_insn_get_bl_value();
280 		break;
281 	case AARCH64_INSN_BRANCH_NOLINK:
282 		insn = aarch64_insn_get_b_value();
283 		break;
284 	default:
285 		pr_err("%s: unknown branch encoding %d\n", __func__, type);
286 		return AARCH64_BREAK_FAULT;
287 	}
288 
289 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
290 					     offset >> 2);
291 }
292 
293 u32 aarch64_insn_gen_comp_branch_imm(unsigned long pc, unsigned long addr,
294 				     enum aarch64_insn_register reg,
295 				     enum aarch64_insn_variant variant,
296 				     enum aarch64_insn_branch_type type)
297 {
298 	u32 insn;
299 	long offset;
300 
301 	offset = label_imm_common(pc, addr, SZ_1M);
302 	if (offset >= SZ_1M)
303 		return AARCH64_BREAK_FAULT;
304 
305 	switch (type) {
306 	case AARCH64_INSN_BRANCH_COMP_ZERO:
307 		insn = aarch64_insn_get_cbz_value();
308 		break;
309 	case AARCH64_INSN_BRANCH_COMP_NONZERO:
310 		insn = aarch64_insn_get_cbnz_value();
311 		break;
312 	default:
313 		pr_err("%s: unknown branch encoding %d\n", __func__, type);
314 		return AARCH64_BREAK_FAULT;
315 	}
316 
317 	switch (variant) {
318 	case AARCH64_INSN_VARIANT_32BIT:
319 		break;
320 	case AARCH64_INSN_VARIANT_64BIT:
321 		insn |= AARCH64_INSN_SF_BIT;
322 		break;
323 	default:
324 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
325 		return AARCH64_BREAK_FAULT;
326 	}
327 
328 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
329 
330 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
331 					     offset >> 2);
332 }
333 
334 u32 aarch64_insn_gen_cond_branch_imm(unsigned long pc, unsigned long addr,
335 				     enum aarch64_insn_condition cond)
336 {
337 	u32 insn;
338 	long offset;
339 
340 	offset = label_imm_common(pc, addr, SZ_1M);
341 
342 	insn = aarch64_insn_get_bcond_value();
343 
344 	if (cond < AARCH64_INSN_COND_EQ || cond > AARCH64_INSN_COND_AL) {
345 		pr_err("%s: unknown condition encoding %d\n", __func__, cond);
346 		return AARCH64_BREAK_FAULT;
347 	}
348 	insn |= cond;
349 
350 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
351 					     offset >> 2);
352 }
353 
354 u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg,
355 				enum aarch64_insn_branch_type type)
356 {
357 	u32 insn;
358 
359 	switch (type) {
360 	case AARCH64_INSN_BRANCH_NOLINK:
361 		insn = aarch64_insn_get_br_value();
362 		break;
363 	case AARCH64_INSN_BRANCH_LINK:
364 		insn = aarch64_insn_get_blr_value();
365 		break;
366 	case AARCH64_INSN_BRANCH_RETURN:
367 		insn = aarch64_insn_get_ret_value();
368 		break;
369 	default:
370 		pr_err("%s: unknown branch encoding %d\n", __func__, type);
371 		return AARCH64_BREAK_FAULT;
372 	}
373 
374 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, reg);
375 }
376 
377 u32 aarch64_insn_gen_load_store_reg(enum aarch64_insn_register reg,
378 				    enum aarch64_insn_register base,
379 				    enum aarch64_insn_register offset,
380 				    enum aarch64_insn_size_type size,
381 				    enum aarch64_insn_ldst_type type)
382 {
383 	u32 insn;
384 
385 	switch (type) {
386 	case AARCH64_INSN_LDST_LOAD_REG_OFFSET:
387 		insn = aarch64_insn_get_ldr_reg_value();
388 		break;
389 	case AARCH64_INSN_LDST_SIGNED_LOAD_REG_OFFSET:
390 		insn = aarch64_insn_get_signed_ldr_reg_value();
391 		break;
392 	case AARCH64_INSN_LDST_STORE_REG_OFFSET:
393 		insn = aarch64_insn_get_str_reg_value();
394 		break;
395 	default:
396 		pr_err("%s: unknown load/store encoding %d\n", __func__, type);
397 		return AARCH64_BREAK_FAULT;
398 	}
399 
400 	insn = aarch64_insn_encode_ldst_size(size, insn);
401 
402 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
403 
404 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
405 					    base);
406 
407 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
408 					    offset);
409 }
410 
411 u32 aarch64_insn_gen_load_store_imm(enum aarch64_insn_register reg,
412 				    enum aarch64_insn_register base,
413 				    unsigned int imm,
414 				    enum aarch64_insn_size_type size,
415 				    enum aarch64_insn_ldst_type type)
416 {
417 	u32 insn;
418 	u32 shift;
419 
420 	if (size < AARCH64_INSN_SIZE_8 || size > AARCH64_INSN_SIZE_64) {
421 		pr_err("%s: unknown size encoding %d\n", __func__, type);
422 		return AARCH64_BREAK_FAULT;
423 	}
424 
425 	shift = aarch64_insn_ldst_size[size];
426 	if (imm & ~(BIT(12 + shift) - BIT(shift))) {
427 		pr_err("%s: invalid imm: %d\n", __func__, imm);
428 		return AARCH64_BREAK_FAULT;
429 	}
430 
431 	imm >>= shift;
432 
433 	switch (type) {
434 	case AARCH64_INSN_LDST_LOAD_IMM_OFFSET:
435 		insn = aarch64_insn_get_ldr_imm_value();
436 		break;
437 	case AARCH64_INSN_LDST_SIGNED_LOAD_IMM_OFFSET:
438 		insn = aarch64_insn_get_signed_load_imm_value();
439 		break;
440 	case AARCH64_INSN_LDST_STORE_IMM_OFFSET:
441 		insn = aarch64_insn_get_str_imm_value();
442 		break;
443 	default:
444 		pr_err("%s: unknown load/store encoding %d\n", __func__, type);
445 		return AARCH64_BREAK_FAULT;
446 	}
447 
448 	insn = aarch64_insn_encode_ldst_size(size, insn);
449 
450 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
451 
452 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
453 					    base);
454 
455 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_12, insn, imm);
456 }
457 
458 u32 aarch64_insn_gen_load_literal(unsigned long pc, unsigned long addr,
459 				  enum aarch64_insn_register reg,
460 				  bool is64bit)
461 {
462 	u32 insn;
463 	long offset;
464 
465 	offset = label_imm_common(pc, addr, SZ_1M);
466 	if (offset >= SZ_1M)
467 		return AARCH64_BREAK_FAULT;
468 
469 	insn = aarch64_insn_get_ldr_lit_value();
470 
471 	if (is64bit)
472 		insn |= BIT(30);
473 
474 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
475 
476 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
477 					     offset >> 2);
478 }
479 
480 u32 aarch64_insn_gen_load_store_pair(enum aarch64_insn_register reg1,
481 				     enum aarch64_insn_register reg2,
482 				     enum aarch64_insn_register base,
483 				     int offset,
484 				     enum aarch64_insn_variant variant,
485 				     enum aarch64_insn_ldst_type type)
486 {
487 	u32 insn;
488 	int shift;
489 
490 	switch (type) {
491 	case AARCH64_INSN_LDST_LOAD_PAIR_PRE_INDEX:
492 		insn = aarch64_insn_get_ldp_pre_value();
493 		break;
494 	case AARCH64_INSN_LDST_STORE_PAIR_PRE_INDEX:
495 		insn = aarch64_insn_get_stp_pre_value();
496 		break;
497 	case AARCH64_INSN_LDST_LOAD_PAIR_POST_INDEX:
498 		insn = aarch64_insn_get_ldp_post_value();
499 		break;
500 	case AARCH64_INSN_LDST_STORE_PAIR_POST_INDEX:
501 		insn = aarch64_insn_get_stp_post_value();
502 		break;
503 	default:
504 		pr_err("%s: unknown load/store encoding %d\n", __func__, type);
505 		return AARCH64_BREAK_FAULT;
506 	}
507 
508 	switch (variant) {
509 	case AARCH64_INSN_VARIANT_32BIT:
510 		if ((offset & 0x3) || (offset < -256) || (offset > 252)) {
511 			pr_err("%s: offset must be multiples of 4 in the range of [-256, 252] %d\n",
512 			       __func__, offset);
513 			return AARCH64_BREAK_FAULT;
514 		}
515 		shift = 2;
516 		break;
517 	case AARCH64_INSN_VARIANT_64BIT:
518 		if ((offset & 0x7) || (offset < -512) || (offset > 504)) {
519 			pr_err("%s: offset must be multiples of 8 in the range of [-512, 504] %d\n",
520 			       __func__, offset);
521 			return AARCH64_BREAK_FAULT;
522 		}
523 		shift = 3;
524 		insn |= AARCH64_INSN_SF_BIT;
525 		break;
526 	default:
527 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
528 		return AARCH64_BREAK_FAULT;
529 	}
530 
531 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
532 					    reg1);
533 
534 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT2, insn,
535 					    reg2);
536 
537 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
538 					    base);
539 
540 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_7, insn,
541 					     offset >> shift);
542 }
543 
544 u32 aarch64_insn_gen_load_acq_store_rel(enum aarch64_insn_register reg,
545 					enum aarch64_insn_register base,
546 					enum aarch64_insn_size_type size,
547 					enum aarch64_insn_ldst_type type)
548 {
549 	u32 insn;
550 
551 	switch (type) {
552 	case AARCH64_INSN_LDST_LOAD_ACQ:
553 		insn = aarch64_insn_get_load_acq_value();
554 		break;
555 	case AARCH64_INSN_LDST_STORE_REL:
556 		insn = aarch64_insn_get_store_rel_value();
557 		break;
558 	default:
559 		pr_err("%s: unknown load-acquire/store-release encoding %d\n",
560 		       __func__, type);
561 		return AARCH64_BREAK_FAULT;
562 	}
563 
564 	insn = aarch64_insn_encode_ldst_size(size, insn);
565 
566 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
567 					    reg);
568 
569 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
570 					    base);
571 }
572 
573 u32 aarch64_insn_gen_load_store_ex(enum aarch64_insn_register reg,
574 				   enum aarch64_insn_register base,
575 				   enum aarch64_insn_register state,
576 				   enum aarch64_insn_size_type size,
577 				   enum aarch64_insn_ldst_type type)
578 {
579 	u32 insn;
580 
581 	switch (type) {
582 	case AARCH64_INSN_LDST_LOAD_EX:
583 	case AARCH64_INSN_LDST_LOAD_ACQ_EX:
584 		insn = aarch64_insn_get_load_ex_value();
585 		if (type == AARCH64_INSN_LDST_LOAD_ACQ_EX)
586 			insn |= BIT(15);
587 		break;
588 	case AARCH64_INSN_LDST_STORE_EX:
589 	case AARCH64_INSN_LDST_STORE_REL_EX:
590 		insn = aarch64_insn_get_store_ex_value();
591 		if (type == AARCH64_INSN_LDST_STORE_REL_EX)
592 			insn |= BIT(15);
593 		break;
594 	default:
595 		pr_err("%s: unknown load/store exclusive encoding %d\n", __func__, type);
596 		return AARCH64_BREAK_FAULT;
597 	}
598 
599 	insn = aarch64_insn_encode_ldst_size(size, insn);
600 
601 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
602 					    reg);
603 
604 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
605 					    base);
606 
607 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT2, insn,
608 					    AARCH64_INSN_REG_ZR);
609 
610 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RS, insn,
611 					    state);
612 }
613 
614 static u32 aarch64_insn_encode_ldst_order(enum aarch64_insn_mem_order_type type,
615 					  u32 insn)
616 {
617 	u32 order;
618 
619 	switch (type) {
620 	case AARCH64_INSN_MEM_ORDER_NONE:
621 		order = 0;
622 		break;
623 	case AARCH64_INSN_MEM_ORDER_ACQ:
624 		order = 2;
625 		break;
626 	case AARCH64_INSN_MEM_ORDER_REL:
627 		order = 1;
628 		break;
629 	case AARCH64_INSN_MEM_ORDER_ACQREL:
630 		order = 3;
631 		break;
632 	default:
633 		pr_err("%s: unknown mem order %d\n", __func__, type);
634 		return AARCH64_BREAK_FAULT;
635 	}
636 
637 	insn &= ~GENMASK(23, 22);
638 	insn |= order << 22;
639 
640 	return insn;
641 }
642 
643 u32 aarch64_insn_gen_atomic_ld_op(enum aarch64_insn_register result,
644 				  enum aarch64_insn_register address,
645 				  enum aarch64_insn_register value,
646 				  enum aarch64_insn_size_type size,
647 				  enum aarch64_insn_mem_atomic_op op,
648 				  enum aarch64_insn_mem_order_type order)
649 {
650 	u32 insn;
651 
652 	switch (op) {
653 	case AARCH64_INSN_MEM_ATOMIC_ADD:
654 		insn = aarch64_insn_get_ldadd_value();
655 		break;
656 	case AARCH64_INSN_MEM_ATOMIC_CLR:
657 		insn = aarch64_insn_get_ldclr_value();
658 		break;
659 	case AARCH64_INSN_MEM_ATOMIC_EOR:
660 		insn = aarch64_insn_get_ldeor_value();
661 		break;
662 	case AARCH64_INSN_MEM_ATOMIC_SET:
663 		insn = aarch64_insn_get_ldset_value();
664 		break;
665 	case AARCH64_INSN_MEM_ATOMIC_SWP:
666 		insn = aarch64_insn_get_swp_value();
667 		break;
668 	default:
669 		pr_err("%s: unimplemented mem atomic op %d\n", __func__, op);
670 		return AARCH64_BREAK_FAULT;
671 	}
672 
673 	switch (size) {
674 	case AARCH64_INSN_SIZE_32:
675 	case AARCH64_INSN_SIZE_64:
676 		break;
677 	default:
678 		pr_err("%s: unimplemented size encoding %d\n", __func__, size);
679 		return AARCH64_BREAK_FAULT;
680 	}
681 
682 	insn = aarch64_insn_encode_ldst_size(size, insn);
683 
684 	insn = aarch64_insn_encode_ldst_order(order, insn);
685 
686 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
687 					    result);
688 
689 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
690 					    address);
691 
692 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RS, insn,
693 					    value);
694 }
695 
696 static u32 aarch64_insn_encode_cas_order(enum aarch64_insn_mem_order_type type,
697 					 u32 insn)
698 {
699 	u32 order;
700 
701 	switch (type) {
702 	case AARCH64_INSN_MEM_ORDER_NONE:
703 		order = 0;
704 		break;
705 	case AARCH64_INSN_MEM_ORDER_ACQ:
706 		order = BIT(22);
707 		break;
708 	case AARCH64_INSN_MEM_ORDER_REL:
709 		order = BIT(15);
710 		break;
711 	case AARCH64_INSN_MEM_ORDER_ACQREL:
712 		order = BIT(15) | BIT(22);
713 		break;
714 	default:
715 		pr_err("%s: unknown mem order %d\n", __func__, type);
716 		return AARCH64_BREAK_FAULT;
717 	}
718 
719 	insn &= ~(BIT(15) | BIT(22));
720 	insn |= order;
721 
722 	return insn;
723 }
724 
725 u32 aarch64_insn_gen_cas(enum aarch64_insn_register result,
726 			 enum aarch64_insn_register address,
727 			 enum aarch64_insn_register value,
728 			 enum aarch64_insn_size_type size,
729 			 enum aarch64_insn_mem_order_type order)
730 {
731 	u32 insn;
732 
733 	switch (size) {
734 	case AARCH64_INSN_SIZE_32:
735 	case AARCH64_INSN_SIZE_64:
736 		break;
737 	default:
738 		pr_err("%s: unimplemented size encoding %d\n", __func__, size);
739 		return AARCH64_BREAK_FAULT;
740 	}
741 
742 	insn = aarch64_insn_get_cas_value();
743 
744 	insn = aarch64_insn_encode_ldst_size(size, insn);
745 
746 	insn = aarch64_insn_encode_cas_order(order, insn);
747 
748 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
749 					    result);
750 
751 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
752 					    address);
753 
754 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RS, insn,
755 					    value);
756 }
757 
758 u32 aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst,
759 				 enum aarch64_insn_register src,
760 				 int imm, enum aarch64_insn_variant variant,
761 				 enum aarch64_insn_adsb_type type)
762 {
763 	u32 insn;
764 
765 	switch (type) {
766 	case AARCH64_INSN_ADSB_ADD:
767 		insn = aarch64_insn_get_add_imm_value();
768 		break;
769 	case AARCH64_INSN_ADSB_SUB:
770 		insn = aarch64_insn_get_sub_imm_value();
771 		break;
772 	case AARCH64_INSN_ADSB_ADD_SETFLAGS:
773 		insn = aarch64_insn_get_adds_imm_value();
774 		break;
775 	case AARCH64_INSN_ADSB_SUB_SETFLAGS:
776 		insn = aarch64_insn_get_subs_imm_value();
777 		break;
778 	default:
779 		pr_err("%s: unknown add/sub encoding %d\n", __func__, type);
780 		return AARCH64_BREAK_FAULT;
781 	}
782 
783 	switch (variant) {
784 	case AARCH64_INSN_VARIANT_32BIT:
785 		break;
786 	case AARCH64_INSN_VARIANT_64BIT:
787 		insn |= AARCH64_INSN_SF_BIT;
788 		break;
789 	default:
790 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
791 		return AARCH64_BREAK_FAULT;
792 	}
793 
794 	/* We can't encode more than a 24bit value (12bit + 12bit shift) */
795 	if (imm & ~(BIT(24) - 1))
796 		goto out;
797 
798 	/* If we have something in the top 12 bits... */
799 	if (imm & ~(SZ_4K - 1)) {
800 		/* ... and in the low 12 bits -> error */
801 		if (imm & (SZ_4K - 1))
802 			goto out;
803 
804 		imm >>= 12;
805 		insn |= AARCH64_INSN_LSL_12;
806 	}
807 
808 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
809 
810 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
811 
812 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_12, insn, imm);
813 
814 out:
815 	pr_err("%s: invalid immediate encoding %d\n", __func__, imm);
816 	return AARCH64_BREAK_FAULT;
817 }
818 
819 u32 aarch64_insn_gen_bitfield(enum aarch64_insn_register dst,
820 			      enum aarch64_insn_register src,
821 			      int immr, int imms,
822 			      enum aarch64_insn_variant variant,
823 			      enum aarch64_insn_bitfield_type type)
824 {
825 	u32 insn;
826 	u32 mask;
827 
828 	switch (type) {
829 	case AARCH64_INSN_BITFIELD_MOVE:
830 		insn = aarch64_insn_get_bfm_value();
831 		break;
832 	case AARCH64_INSN_BITFIELD_MOVE_UNSIGNED:
833 		insn = aarch64_insn_get_ubfm_value();
834 		break;
835 	case AARCH64_INSN_BITFIELD_MOVE_SIGNED:
836 		insn = aarch64_insn_get_sbfm_value();
837 		break;
838 	default:
839 		pr_err("%s: unknown bitfield encoding %d\n", __func__, type);
840 		return AARCH64_BREAK_FAULT;
841 	}
842 
843 	switch (variant) {
844 	case AARCH64_INSN_VARIANT_32BIT:
845 		mask = GENMASK(4, 0);
846 		break;
847 	case AARCH64_INSN_VARIANT_64BIT:
848 		insn |= AARCH64_INSN_SF_BIT | AARCH64_INSN_N_BIT;
849 		mask = GENMASK(5, 0);
850 		break;
851 	default:
852 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
853 		return AARCH64_BREAK_FAULT;
854 	}
855 
856 	if (immr & ~mask) {
857 		pr_err("%s: invalid immr encoding %d\n", __func__, immr);
858 		return AARCH64_BREAK_FAULT;
859 	}
860 	if (imms & ~mask) {
861 		pr_err("%s: invalid imms encoding %d\n", __func__, imms);
862 		return AARCH64_BREAK_FAULT;
863 	}
864 
865 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
866 
867 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
868 
869 	insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_R, insn, immr);
870 
871 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, imms);
872 }
873 
874 u32 aarch64_insn_gen_movewide(enum aarch64_insn_register dst,
875 			      int imm, int shift,
876 			      enum aarch64_insn_variant variant,
877 			      enum aarch64_insn_movewide_type type)
878 {
879 	u32 insn;
880 
881 	switch (type) {
882 	case AARCH64_INSN_MOVEWIDE_ZERO:
883 		insn = aarch64_insn_get_movz_value();
884 		break;
885 	case AARCH64_INSN_MOVEWIDE_KEEP:
886 		insn = aarch64_insn_get_movk_value();
887 		break;
888 	case AARCH64_INSN_MOVEWIDE_INVERSE:
889 		insn = aarch64_insn_get_movn_value();
890 		break;
891 	default:
892 		pr_err("%s: unknown movewide encoding %d\n", __func__, type);
893 		return AARCH64_BREAK_FAULT;
894 	}
895 
896 	if (imm & ~(SZ_64K - 1)) {
897 		pr_err("%s: invalid immediate encoding %d\n", __func__, imm);
898 		return AARCH64_BREAK_FAULT;
899 	}
900 
901 	switch (variant) {
902 	case AARCH64_INSN_VARIANT_32BIT:
903 		if (shift != 0 && shift != 16) {
904 			pr_err("%s: invalid shift encoding %d\n", __func__,
905 			       shift);
906 			return AARCH64_BREAK_FAULT;
907 		}
908 		break;
909 	case AARCH64_INSN_VARIANT_64BIT:
910 		insn |= AARCH64_INSN_SF_BIT;
911 		if (shift != 0 && shift != 16 && shift != 32 && shift != 48) {
912 			pr_err("%s: invalid shift encoding %d\n", __func__,
913 			       shift);
914 			return AARCH64_BREAK_FAULT;
915 		}
916 		break;
917 	default:
918 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
919 		return AARCH64_BREAK_FAULT;
920 	}
921 
922 	insn |= (shift >> 4) << 21;
923 
924 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
925 
926 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_16, insn, imm);
927 }
928 
929 u32 aarch64_insn_gen_add_sub_shifted_reg(enum aarch64_insn_register dst,
930 					 enum aarch64_insn_register src,
931 					 enum aarch64_insn_register reg,
932 					 int shift,
933 					 enum aarch64_insn_variant variant,
934 					 enum aarch64_insn_adsb_type type)
935 {
936 	u32 insn;
937 
938 	switch (type) {
939 	case AARCH64_INSN_ADSB_ADD:
940 		insn = aarch64_insn_get_add_value();
941 		break;
942 	case AARCH64_INSN_ADSB_SUB:
943 		insn = aarch64_insn_get_sub_value();
944 		break;
945 	case AARCH64_INSN_ADSB_ADD_SETFLAGS:
946 		insn = aarch64_insn_get_adds_value();
947 		break;
948 	case AARCH64_INSN_ADSB_SUB_SETFLAGS:
949 		insn = aarch64_insn_get_subs_value();
950 		break;
951 	default:
952 		pr_err("%s: unknown add/sub encoding %d\n", __func__, type);
953 		return AARCH64_BREAK_FAULT;
954 	}
955 
956 	switch (variant) {
957 	case AARCH64_INSN_VARIANT_32BIT:
958 		if (shift & ~(SZ_32 - 1)) {
959 			pr_err("%s: invalid shift encoding %d\n", __func__,
960 			       shift);
961 			return AARCH64_BREAK_FAULT;
962 		}
963 		break;
964 	case AARCH64_INSN_VARIANT_64BIT:
965 		insn |= AARCH64_INSN_SF_BIT;
966 		if (shift & ~(SZ_64 - 1)) {
967 			pr_err("%s: invalid shift encoding %d\n", __func__,
968 			       shift);
969 			return AARCH64_BREAK_FAULT;
970 		}
971 		break;
972 	default:
973 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
974 		return AARCH64_BREAK_FAULT;
975 	}
976 
977 
978 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
979 
980 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
981 
982 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
983 
984 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
985 }
986 
987 u32 aarch64_insn_gen_data1(enum aarch64_insn_register dst,
988 			   enum aarch64_insn_register src,
989 			   enum aarch64_insn_variant variant,
990 			   enum aarch64_insn_data1_type type)
991 {
992 	u32 insn;
993 
994 	switch (type) {
995 	case AARCH64_INSN_DATA1_REVERSE_16:
996 		insn = aarch64_insn_get_rev16_value();
997 		break;
998 	case AARCH64_INSN_DATA1_REVERSE_32:
999 		insn = aarch64_insn_get_rev32_value();
1000 		break;
1001 	case AARCH64_INSN_DATA1_REVERSE_64:
1002 		if (variant != AARCH64_INSN_VARIANT_64BIT) {
1003 			pr_err("%s: invalid variant for reverse64 %d\n",
1004 			       __func__, variant);
1005 			return AARCH64_BREAK_FAULT;
1006 		}
1007 		insn = aarch64_insn_get_rev64_value();
1008 		break;
1009 	default:
1010 		pr_err("%s: unknown data1 encoding %d\n", __func__, type);
1011 		return AARCH64_BREAK_FAULT;
1012 	}
1013 
1014 	switch (variant) {
1015 	case AARCH64_INSN_VARIANT_32BIT:
1016 		break;
1017 	case AARCH64_INSN_VARIANT_64BIT:
1018 		insn |= AARCH64_INSN_SF_BIT;
1019 		break;
1020 	default:
1021 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1022 		return AARCH64_BREAK_FAULT;
1023 	}
1024 
1025 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1026 
1027 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1028 }
1029 
1030 u32 aarch64_insn_gen_data2(enum aarch64_insn_register dst,
1031 			   enum aarch64_insn_register src,
1032 			   enum aarch64_insn_register reg,
1033 			   enum aarch64_insn_variant variant,
1034 			   enum aarch64_insn_data2_type type)
1035 {
1036 	u32 insn;
1037 
1038 	switch (type) {
1039 	case AARCH64_INSN_DATA2_UDIV:
1040 		insn = aarch64_insn_get_udiv_value();
1041 		break;
1042 	case AARCH64_INSN_DATA2_SDIV:
1043 		insn = aarch64_insn_get_sdiv_value();
1044 		break;
1045 	case AARCH64_INSN_DATA2_LSLV:
1046 		insn = aarch64_insn_get_lslv_value();
1047 		break;
1048 	case AARCH64_INSN_DATA2_LSRV:
1049 		insn = aarch64_insn_get_lsrv_value();
1050 		break;
1051 	case AARCH64_INSN_DATA2_ASRV:
1052 		insn = aarch64_insn_get_asrv_value();
1053 		break;
1054 	case AARCH64_INSN_DATA2_RORV:
1055 		insn = aarch64_insn_get_rorv_value();
1056 		break;
1057 	default:
1058 		pr_err("%s: unknown data2 encoding %d\n", __func__, type);
1059 		return AARCH64_BREAK_FAULT;
1060 	}
1061 
1062 	switch (variant) {
1063 	case AARCH64_INSN_VARIANT_32BIT:
1064 		break;
1065 	case AARCH64_INSN_VARIANT_64BIT:
1066 		insn |= AARCH64_INSN_SF_BIT;
1067 		break;
1068 	default:
1069 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1070 		return AARCH64_BREAK_FAULT;
1071 	}
1072 
1073 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1074 
1075 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1076 
1077 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
1078 }
1079 
1080 u32 aarch64_insn_gen_data3(enum aarch64_insn_register dst,
1081 			   enum aarch64_insn_register src,
1082 			   enum aarch64_insn_register reg1,
1083 			   enum aarch64_insn_register reg2,
1084 			   enum aarch64_insn_variant variant,
1085 			   enum aarch64_insn_data3_type type)
1086 {
1087 	u32 insn;
1088 
1089 	switch (type) {
1090 	case AARCH64_INSN_DATA3_MADD:
1091 		insn = aarch64_insn_get_madd_value();
1092 		break;
1093 	case AARCH64_INSN_DATA3_MSUB:
1094 		insn = aarch64_insn_get_msub_value();
1095 		break;
1096 	default:
1097 		pr_err("%s: unknown data3 encoding %d\n", __func__, type);
1098 		return AARCH64_BREAK_FAULT;
1099 	}
1100 
1101 	switch (variant) {
1102 	case AARCH64_INSN_VARIANT_32BIT:
1103 		break;
1104 	case AARCH64_INSN_VARIANT_64BIT:
1105 		insn |= AARCH64_INSN_SF_BIT;
1106 		break;
1107 	default:
1108 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1109 		return AARCH64_BREAK_FAULT;
1110 	}
1111 
1112 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1113 
1114 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RA, insn, src);
1115 
1116 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
1117 					    reg1);
1118 
1119 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
1120 					    reg2);
1121 }
1122 
1123 u32 aarch64_insn_gen_logical_shifted_reg(enum aarch64_insn_register dst,
1124 					 enum aarch64_insn_register src,
1125 					 enum aarch64_insn_register reg,
1126 					 int shift,
1127 					 enum aarch64_insn_variant variant,
1128 					 enum aarch64_insn_logic_type type)
1129 {
1130 	u32 insn;
1131 
1132 	switch (type) {
1133 	case AARCH64_INSN_LOGIC_AND:
1134 		insn = aarch64_insn_get_and_value();
1135 		break;
1136 	case AARCH64_INSN_LOGIC_BIC:
1137 		insn = aarch64_insn_get_bic_value();
1138 		break;
1139 	case AARCH64_INSN_LOGIC_ORR:
1140 		insn = aarch64_insn_get_orr_value();
1141 		break;
1142 	case AARCH64_INSN_LOGIC_ORN:
1143 		insn = aarch64_insn_get_orn_value();
1144 		break;
1145 	case AARCH64_INSN_LOGIC_EOR:
1146 		insn = aarch64_insn_get_eor_value();
1147 		break;
1148 	case AARCH64_INSN_LOGIC_EON:
1149 		insn = aarch64_insn_get_eon_value();
1150 		break;
1151 	case AARCH64_INSN_LOGIC_AND_SETFLAGS:
1152 		insn = aarch64_insn_get_ands_value();
1153 		break;
1154 	case AARCH64_INSN_LOGIC_BIC_SETFLAGS:
1155 		insn = aarch64_insn_get_bics_value();
1156 		break;
1157 	default:
1158 		pr_err("%s: unknown logical encoding %d\n", __func__, type);
1159 		return AARCH64_BREAK_FAULT;
1160 	}
1161 
1162 	switch (variant) {
1163 	case AARCH64_INSN_VARIANT_32BIT:
1164 		if (shift & ~(SZ_32 - 1)) {
1165 			pr_err("%s: invalid shift encoding %d\n", __func__,
1166 			       shift);
1167 			return AARCH64_BREAK_FAULT;
1168 		}
1169 		break;
1170 	case AARCH64_INSN_VARIANT_64BIT:
1171 		insn |= AARCH64_INSN_SF_BIT;
1172 		if (shift & ~(SZ_64 - 1)) {
1173 			pr_err("%s: invalid shift encoding %d\n", __func__,
1174 			       shift);
1175 			return AARCH64_BREAK_FAULT;
1176 		}
1177 		break;
1178 	default:
1179 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1180 		return AARCH64_BREAK_FAULT;
1181 	}
1182 
1183 
1184 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1185 
1186 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1187 
1188 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
1189 
1190 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
1191 }
1192 
1193 /*
1194  * MOV (register) is architecturally an alias of ORR (shifted register) where
1195  * MOV <*d>, <*m> is equivalent to ORR <*d>, <*ZR>, <*m>
1196  */
1197 u32 aarch64_insn_gen_move_reg(enum aarch64_insn_register dst,
1198 			      enum aarch64_insn_register src,
1199 			      enum aarch64_insn_variant variant)
1200 {
1201 	return aarch64_insn_gen_logical_shifted_reg(dst, AARCH64_INSN_REG_ZR,
1202 						    src, 0, variant,
1203 						    AARCH64_INSN_LOGIC_ORR);
1204 }
1205 
1206 u32 aarch64_insn_gen_adr(unsigned long pc, unsigned long addr,
1207 			 enum aarch64_insn_register reg,
1208 			 enum aarch64_insn_adr_type type)
1209 {
1210 	u32 insn;
1211 	s32 offset;
1212 
1213 	switch (type) {
1214 	case AARCH64_INSN_ADR_TYPE_ADR:
1215 		insn = aarch64_insn_get_adr_value();
1216 		offset = addr - pc;
1217 		break;
1218 	case AARCH64_INSN_ADR_TYPE_ADRP:
1219 		insn = aarch64_insn_get_adrp_value();
1220 		offset = (addr - ALIGN_DOWN(pc, SZ_4K)) >> 12;
1221 		break;
1222 	default:
1223 		pr_err("%s: unknown adr encoding %d\n", __func__, type);
1224 		return AARCH64_BREAK_FAULT;
1225 	}
1226 
1227 	if (offset < -SZ_1M || offset >= SZ_1M)
1228 		return AARCH64_BREAK_FAULT;
1229 
1230 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, reg);
1231 
1232 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_ADR, insn, offset);
1233 }
1234 
1235 /*
1236  * Decode the imm field of a branch, and return the byte offset as a
1237  * signed value (so it can be used when computing a new branch
1238  * target).
1239  */
1240 s32 aarch64_get_branch_offset(u32 insn)
1241 {
1242 	s32 imm;
1243 
1244 	if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn)) {
1245 		imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_26, insn);
1246 		return (imm << 6) >> 4;
1247 	}
1248 
1249 	if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
1250 	    aarch64_insn_is_bcond(insn)) {
1251 		imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_19, insn);
1252 		return (imm << 13) >> 11;
1253 	}
1254 
1255 	if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn)) {
1256 		imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_14, insn);
1257 		return (imm << 18) >> 16;
1258 	}
1259 
1260 	/* Unhandled instruction */
1261 	BUG();
1262 }
1263 
1264 /*
1265  * Encode the displacement of a branch in the imm field and return the
1266  * updated instruction.
1267  */
1268 u32 aarch64_set_branch_offset(u32 insn, s32 offset)
1269 {
1270 	if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn))
1271 		return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
1272 						     offset >> 2);
1273 
1274 	if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
1275 	    aarch64_insn_is_bcond(insn))
1276 		return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
1277 						     offset >> 2);
1278 
1279 	if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn))
1280 		return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_14, insn,
1281 						     offset >> 2);
1282 
1283 	/* Unhandled instruction */
1284 	BUG();
1285 }
1286 
1287 s32 aarch64_insn_adrp_get_offset(u32 insn)
1288 {
1289 	BUG_ON(!aarch64_insn_is_adrp(insn));
1290 	return aarch64_insn_decode_immediate(AARCH64_INSN_IMM_ADR, insn) << 12;
1291 }
1292 
1293 u32 aarch64_insn_adrp_set_offset(u32 insn, s32 offset)
1294 {
1295 	BUG_ON(!aarch64_insn_is_adrp(insn));
1296 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_ADR, insn,
1297 						offset >> 12);
1298 }
1299 
1300 /*
1301  * Extract the Op/CR data from a msr/mrs instruction.
1302  */
1303 u32 aarch64_insn_extract_system_reg(u32 insn)
1304 {
1305 	return (insn & 0x1FFFE0) >> 5;
1306 }
1307 
1308 bool aarch32_insn_is_wide(u32 insn)
1309 {
1310 	return insn >= 0xe800;
1311 }
1312 
1313 /*
1314  * Macros/defines for extracting register numbers from instruction.
1315  */
1316 u32 aarch32_insn_extract_reg_num(u32 insn, int offset)
1317 {
1318 	return (insn & (0xf << offset)) >> offset;
1319 }
1320 
1321 #define OPC2_MASK	0x7
1322 #define OPC2_OFFSET	5
1323 u32 aarch32_insn_mcr_extract_opc2(u32 insn)
1324 {
1325 	return (insn & (OPC2_MASK << OPC2_OFFSET)) >> OPC2_OFFSET;
1326 }
1327 
1328 #define CRM_MASK	0xf
1329 u32 aarch32_insn_mcr_extract_crm(u32 insn)
1330 {
1331 	return insn & CRM_MASK;
1332 }
1333 
1334 static bool range_of_ones(u64 val)
1335 {
1336 	/* Doesn't handle full ones or full zeroes */
1337 	u64 sval = val >> __ffs64(val);
1338 
1339 	/* One of Sean Eron Anderson's bithack tricks */
1340 	return ((sval + 1) & (sval)) == 0;
1341 }
1342 
1343 static u32 aarch64_encode_immediate(u64 imm,
1344 				    enum aarch64_insn_variant variant,
1345 				    u32 insn)
1346 {
1347 	unsigned int immr, imms, n, ones, ror, esz, tmp;
1348 	u64 mask;
1349 
1350 	switch (variant) {
1351 	case AARCH64_INSN_VARIANT_32BIT:
1352 		esz = 32;
1353 		break;
1354 	case AARCH64_INSN_VARIANT_64BIT:
1355 		insn |= AARCH64_INSN_SF_BIT;
1356 		esz = 64;
1357 		break;
1358 	default:
1359 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1360 		return AARCH64_BREAK_FAULT;
1361 	}
1362 
1363 	mask = GENMASK(esz - 1, 0);
1364 
1365 	/* Can't encode full zeroes, full ones, or value wider than the mask */
1366 	if (!imm || imm == mask || imm & ~mask)
1367 		return AARCH64_BREAK_FAULT;
1368 
1369 	/*
1370 	 * Inverse of Replicate(). Try to spot a repeating pattern
1371 	 * with a pow2 stride.
1372 	 */
1373 	for (tmp = esz / 2; tmp >= 2; tmp /= 2) {
1374 		u64 emask = BIT(tmp) - 1;
1375 
1376 		if ((imm & emask) != ((imm >> tmp) & emask))
1377 			break;
1378 
1379 		esz = tmp;
1380 		mask = emask;
1381 	}
1382 
1383 	/* N is only set if we're encoding a 64bit value */
1384 	n = esz == 64;
1385 
1386 	/* Trim imm to the element size */
1387 	imm &= mask;
1388 
1389 	/* That's how many ones we need to encode */
1390 	ones = hweight64(imm);
1391 
1392 	/*
1393 	 * imms is set to (ones - 1), prefixed with a string of ones
1394 	 * and a zero if they fit. Cap it to 6 bits.
1395 	 */
1396 	imms  = ones - 1;
1397 	imms |= 0xf << ffs(esz);
1398 	imms &= BIT(6) - 1;
1399 
1400 	/* Compute the rotation */
1401 	if (range_of_ones(imm)) {
1402 		/*
1403 		 * Pattern: 0..01..10..0
1404 		 *
1405 		 * Compute how many rotate we need to align it right
1406 		 */
1407 		ror = __ffs64(imm);
1408 	} else {
1409 		/*
1410 		 * Pattern: 0..01..10..01..1
1411 		 *
1412 		 * Fill the unused top bits with ones, and check if
1413 		 * the result is a valid immediate (all ones with a
1414 		 * contiguous ranges of zeroes).
1415 		 */
1416 		imm |= ~mask;
1417 		if (!range_of_ones(~imm))
1418 			return AARCH64_BREAK_FAULT;
1419 
1420 		/*
1421 		 * Compute the rotation to get a continuous set of
1422 		 * ones, with the first bit set at position 0
1423 		 */
1424 		ror = fls64(~imm);
1425 	}
1426 
1427 	/*
1428 	 * immr is the number of bits we need to rotate back to the
1429 	 * original set of ones. Note that this is relative to the
1430 	 * element size...
1431 	 */
1432 	immr = (esz - ror) % esz;
1433 
1434 	insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_N, insn, n);
1435 	insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_R, insn, immr);
1436 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, imms);
1437 }
1438 
1439 u32 aarch64_insn_gen_logical_immediate(enum aarch64_insn_logic_type type,
1440 				       enum aarch64_insn_variant variant,
1441 				       enum aarch64_insn_register Rn,
1442 				       enum aarch64_insn_register Rd,
1443 				       u64 imm)
1444 {
1445 	u32 insn;
1446 
1447 	switch (type) {
1448 	case AARCH64_INSN_LOGIC_AND:
1449 		insn = aarch64_insn_get_and_imm_value();
1450 		break;
1451 	case AARCH64_INSN_LOGIC_ORR:
1452 		insn = aarch64_insn_get_orr_imm_value();
1453 		break;
1454 	case AARCH64_INSN_LOGIC_EOR:
1455 		insn = aarch64_insn_get_eor_imm_value();
1456 		break;
1457 	case AARCH64_INSN_LOGIC_AND_SETFLAGS:
1458 		insn = aarch64_insn_get_ands_imm_value();
1459 		break;
1460 	default:
1461 		pr_err("%s: unknown logical encoding %d\n", __func__, type);
1462 		return AARCH64_BREAK_FAULT;
1463 	}
1464 
1465 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, Rd);
1466 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, Rn);
1467 	return aarch64_encode_immediate(imm, variant, insn);
1468 }
1469 
1470 u32 aarch64_insn_gen_extr(enum aarch64_insn_variant variant,
1471 			  enum aarch64_insn_register Rm,
1472 			  enum aarch64_insn_register Rn,
1473 			  enum aarch64_insn_register Rd,
1474 			  u8 lsb)
1475 {
1476 	u32 insn;
1477 
1478 	insn = aarch64_insn_get_extr_value();
1479 
1480 	switch (variant) {
1481 	case AARCH64_INSN_VARIANT_32BIT:
1482 		if (lsb > 31)
1483 			return AARCH64_BREAK_FAULT;
1484 		break;
1485 	case AARCH64_INSN_VARIANT_64BIT:
1486 		if (lsb > 63)
1487 			return AARCH64_BREAK_FAULT;
1488 		insn |= AARCH64_INSN_SF_BIT;
1489 		insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_N, insn, 1);
1490 		break;
1491 	default:
1492 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1493 		return AARCH64_BREAK_FAULT;
1494 	}
1495 
1496 	insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, lsb);
1497 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, Rd);
1498 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, Rn);
1499 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, Rm);
1500 }
1501 
1502 static u32 __get_barrier_crm_val(enum aarch64_insn_mb_type type)
1503 {
1504 	switch (type) {
1505 	case AARCH64_INSN_MB_SY:
1506 		return 0xf;
1507 	case AARCH64_INSN_MB_ST:
1508 		return 0xe;
1509 	case AARCH64_INSN_MB_LD:
1510 		return 0xd;
1511 	case AARCH64_INSN_MB_ISH:
1512 		return 0xb;
1513 	case AARCH64_INSN_MB_ISHST:
1514 		return 0xa;
1515 	case AARCH64_INSN_MB_ISHLD:
1516 		return 0x9;
1517 	case AARCH64_INSN_MB_NSH:
1518 		return 0x7;
1519 	case AARCH64_INSN_MB_NSHST:
1520 		return 0x6;
1521 	case AARCH64_INSN_MB_NSHLD:
1522 		return 0x5;
1523 	default:
1524 		pr_err("%s: unknown barrier type %d\n", __func__, type);
1525 		return AARCH64_BREAK_FAULT;
1526 	}
1527 }
1528 
1529 u32 aarch64_insn_gen_dmb(enum aarch64_insn_mb_type type)
1530 {
1531 	u32 opt;
1532 	u32 insn;
1533 
1534 	opt = __get_barrier_crm_val(type);
1535 	if (opt == AARCH64_BREAK_FAULT)
1536 		return AARCH64_BREAK_FAULT;
1537 
1538 	insn = aarch64_insn_get_dmb_value();
1539 	insn &= ~GENMASK(11, 8);
1540 	insn |= (opt << 8);
1541 
1542 	return insn;
1543 }
1544 
1545 u32 aarch64_insn_gen_dsb(enum aarch64_insn_mb_type type)
1546 {
1547 	u32 opt, insn;
1548 
1549 	opt = __get_barrier_crm_val(type);
1550 	if (opt == AARCH64_BREAK_FAULT)
1551 		return AARCH64_BREAK_FAULT;
1552 
1553 	insn = aarch64_insn_get_dsb_base_value();
1554 	insn &= ~GENMASK(11, 8);
1555 	insn |= (opt << 8);
1556 
1557 	return insn;
1558 }
1559 
1560 u32 aarch64_insn_gen_mrs(enum aarch64_insn_register result,
1561 			 enum aarch64_insn_system_register sysreg)
1562 {
1563 	u32 insn = aarch64_insn_get_mrs_value();
1564 
1565 	insn &= ~GENMASK(19, 0);
1566 	insn |= sysreg << 5;
1567 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT,
1568 					    insn, result);
1569 }
1570