1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (c) 2014 Imagination Technologies Ltd.
7  * Author: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
8  * Author: Markos Chandras <markos.chandras@imgtec.com>
9  *
10  *      MIPS R2 user space instruction emulator for MIPS R6
11  *
12  */
13 #include <linux/bug.h>
14 #include <linux/compiler.h>
15 #include <linux/debugfs.h>
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/ptrace.h>
19 #include <linux/seq_file.h>
20 
21 #include <asm/asm.h>
22 #include <asm/branch.h>
23 #include <asm/break.h>
24 #include <asm/debug.h>
25 #include <asm/fpu.h>
26 #include <asm/fpu_emulator.h>
27 #include <asm/inst.h>
28 #include <asm/mips-r2-to-r6-emul.h>
29 #include <asm/local.h>
30 #include <asm/mipsregs.h>
31 #include <asm/ptrace.h>
32 #include <linux/uaccess.h>
33 
34 #ifdef CONFIG_64BIT
35 #define ADDIU	"daddiu "
36 #define INS	"dins "
37 #define EXT	"dext "
38 #else
39 #define ADDIU	"addiu "
40 #define INS	"ins "
41 #define EXT	"ext "
42 #endif /* CONFIG_64BIT */
43 
44 #define SB	"sb "
45 #define LB	"lb "
46 #define LL	"ll "
47 #define SC	"sc "
48 
49 DEFINE_PER_CPU(struct mips_r2_emulator_stats, mipsr2emustats);
50 DEFINE_PER_CPU(struct mips_r2_emulator_stats, mipsr2bdemustats);
51 DEFINE_PER_CPU(struct mips_r2br_emulator_stats, mipsr2bremustats);
52 
53 extern const unsigned int fpucondbit[8];
54 
55 #define MIPS_R2_EMUL_TOTAL_PASS	10
56 
57 int mipsr2_emulation = 0;
58 
59 static int __init mipsr2emu_enable(char *s)
60 {
61 	mipsr2_emulation = 1;
62 
63 	pr_info("MIPS R2-to-R6 Emulator Enabled!");
64 
65 	return 1;
66 }
67 __setup("mipsr2emu", mipsr2emu_enable);
68 
69 /**
70  * mipsr6_emul - Emulate some frequent R2/R5/R6 instructions in delay slot
71  * for performance instead of the traditional way of using a stack trampoline
72  * which is rather slow.
73  * @regs: Process register set
74  * @ir: Instruction
75  */
76 static inline int mipsr6_emul(struct pt_regs *regs, u32 ir)
77 {
78 	switch (MIPSInst_OPCODE(ir)) {
79 	case addiu_op:
80 		if (MIPSInst_RT(ir))
81 			regs->regs[MIPSInst_RT(ir)] =
82 				(s32)regs->regs[MIPSInst_RS(ir)] +
83 				(s32)MIPSInst_SIMM(ir);
84 		return 0;
85 	case daddiu_op:
86 		if (IS_ENABLED(CONFIG_32BIT))
87 			break;
88 
89 		if (MIPSInst_RT(ir))
90 			regs->regs[MIPSInst_RT(ir)] =
91 				(s64)regs->regs[MIPSInst_RS(ir)] +
92 				(s64)MIPSInst_SIMM(ir);
93 		return 0;
94 	case lwc1_op:
95 	case swc1_op:
96 	case cop1_op:
97 	case cop1x_op:
98 		/* FPU instructions in delay slot */
99 		return -SIGFPE;
100 	case spec_op:
101 		switch (MIPSInst_FUNC(ir)) {
102 		case or_op:
103 			if (MIPSInst_RD(ir))
104 				regs->regs[MIPSInst_RD(ir)] =
105 					regs->regs[MIPSInst_RS(ir)] |
106 					regs->regs[MIPSInst_RT(ir)];
107 			return 0;
108 		case sll_op:
109 			if (MIPSInst_RS(ir))
110 				break;
111 
112 			if (MIPSInst_RD(ir))
113 				regs->regs[MIPSInst_RD(ir)] =
114 					(s32)(((u32)regs->regs[MIPSInst_RT(ir)]) <<
115 						MIPSInst_FD(ir));
116 			return 0;
117 		case srl_op:
118 			if (MIPSInst_RS(ir))
119 				break;
120 
121 			if (MIPSInst_RD(ir))
122 				regs->regs[MIPSInst_RD(ir)] =
123 					(s32)(((u32)regs->regs[MIPSInst_RT(ir)]) >>
124 						MIPSInst_FD(ir));
125 			return 0;
126 		case addu_op:
127 			if (MIPSInst_FD(ir))
128 				break;
129 
130 			if (MIPSInst_RD(ir))
131 				regs->regs[MIPSInst_RD(ir)] =
132 					(s32)((u32)regs->regs[MIPSInst_RS(ir)] +
133 					      (u32)regs->regs[MIPSInst_RT(ir)]);
134 			return 0;
135 		case subu_op:
136 			if (MIPSInst_FD(ir))
137 				break;
138 
139 			if (MIPSInst_RD(ir))
140 				regs->regs[MIPSInst_RD(ir)] =
141 					(s32)((u32)regs->regs[MIPSInst_RS(ir)] -
142 					      (u32)regs->regs[MIPSInst_RT(ir)]);
143 			return 0;
144 		case dsll_op:
145 			if (IS_ENABLED(CONFIG_32BIT) || MIPSInst_RS(ir))
146 				break;
147 
148 			if (MIPSInst_RD(ir))
149 				regs->regs[MIPSInst_RD(ir)] =
150 					(s64)(((u64)regs->regs[MIPSInst_RT(ir)]) <<
151 						MIPSInst_FD(ir));
152 			return 0;
153 		case dsrl_op:
154 			if (IS_ENABLED(CONFIG_32BIT) || MIPSInst_RS(ir))
155 				break;
156 
157 			if (MIPSInst_RD(ir))
158 				regs->regs[MIPSInst_RD(ir)] =
159 					(s64)(((u64)regs->regs[MIPSInst_RT(ir)]) >>
160 						MIPSInst_FD(ir));
161 			return 0;
162 		case daddu_op:
163 			if (IS_ENABLED(CONFIG_32BIT) || MIPSInst_FD(ir))
164 				break;
165 
166 			if (MIPSInst_RD(ir))
167 				regs->regs[MIPSInst_RD(ir)] =
168 					(u64)regs->regs[MIPSInst_RS(ir)] +
169 					(u64)regs->regs[MIPSInst_RT(ir)];
170 			return 0;
171 		case dsubu_op:
172 			if (IS_ENABLED(CONFIG_32BIT) || MIPSInst_FD(ir))
173 				break;
174 
175 			if (MIPSInst_RD(ir))
176 				regs->regs[MIPSInst_RD(ir)] =
177 					(s64)((u64)regs->regs[MIPSInst_RS(ir)] -
178 					      (u64)regs->regs[MIPSInst_RT(ir)]);
179 			return 0;
180 		}
181 		break;
182 	default:
183 		pr_debug("No fastpath BD emulation for instruction 0x%08x (op: %02x)\n",
184 			 ir, MIPSInst_OPCODE(ir));
185 	}
186 
187 	return SIGILL;
188 }
189 
190 /**
191  * movf_func - Emulate a MOVF instruction
192  * @regs: Process register set
193  * @ir: Instruction
194  *
195  * Returns 0 since it always succeeds.
196  */
197 static int movf_func(struct pt_regs *regs, u32 ir)
198 {
199 	u32 csr;
200 	u32 cond;
201 
202 	csr = current->thread.fpu.fcr31;
203 	cond = fpucondbit[MIPSInst_RT(ir) >> 2];
204 
205 	if (((csr & cond) == 0) && MIPSInst_RD(ir))
206 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
207 
208 	MIPS_R2_STATS(movs);
209 
210 	return 0;
211 }
212 
213 /**
214  * movt_func - Emulate a MOVT instruction
215  * @regs: Process register set
216  * @ir: Instruction
217  *
218  * Returns 0 since it always succeeds.
219  */
220 static int movt_func(struct pt_regs *regs, u32 ir)
221 {
222 	u32 csr;
223 	u32 cond;
224 
225 	csr = current->thread.fpu.fcr31;
226 	cond = fpucondbit[MIPSInst_RT(ir) >> 2];
227 
228 	if (((csr & cond) != 0) && MIPSInst_RD(ir))
229 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
230 
231 	MIPS_R2_STATS(movs);
232 
233 	return 0;
234 }
235 
236 /**
237  * jr_func - Emulate a JR instruction.
238  * @pt_regs: Process register set
239  * @ir: Instruction
240  *
241  * Returns SIGILL if JR was in delay slot, SIGEMT if we
242  * can't compute the EPC, SIGSEGV if we can't access the
243  * userland instruction or 0 on success.
244  */
245 static int jr_func(struct pt_regs *regs, u32 ir)
246 {
247 	int err;
248 	unsigned long cepc, epc, nepc;
249 	u32 nir;
250 
251 	if (delay_slot(regs))
252 		return SIGILL;
253 
254 	/* EPC after the RI/JR instruction */
255 	nepc = regs->cp0_epc;
256 	/* Roll back to the reserved R2 JR instruction */
257 	regs->cp0_epc -= 4;
258 	epc = regs->cp0_epc;
259 	err = __compute_return_epc(regs);
260 
261 	if (err < 0)
262 		return SIGEMT;
263 
264 
265 	/* Computed EPC */
266 	cepc = regs->cp0_epc;
267 
268 	/* Get DS instruction */
269 	err = __get_user(nir, (u32 __user *)nepc);
270 	if (err)
271 		return SIGSEGV;
272 
273 	MIPS_R2BR_STATS(jrs);
274 
275 	/* If nir == 0(NOP), then nothing else to do */
276 	if (nir) {
277 		/*
278 		 * Negative err means FPU instruction in BD-slot,
279 		 * Zero err means 'BD-slot emulation done'
280 		 * For anything else we go back to trampoline emulation.
281 		 */
282 		err = mipsr6_emul(regs, nir);
283 		if (err > 0) {
284 			regs->cp0_epc = nepc;
285 			err = mips_dsemul(regs, nir, epc, cepc);
286 			if (err == SIGILL)
287 				err = SIGEMT;
288 			MIPS_R2_STATS(dsemul);
289 		}
290 	}
291 
292 	return err;
293 }
294 
295 /**
296  * movz_func - Emulate a MOVZ instruction
297  * @regs: Process register set
298  * @ir: Instruction
299  *
300  * Returns 0 since it always succeeds.
301  */
302 static int movz_func(struct pt_regs *regs, u32 ir)
303 {
304 	if (((regs->regs[MIPSInst_RT(ir)]) == 0) && MIPSInst_RD(ir))
305 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
306 	MIPS_R2_STATS(movs);
307 
308 	return 0;
309 }
310 
311 /**
312  * movn_func - Emulate a MOVZ instruction
313  * @regs: Process register set
314  * @ir: Instruction
315  *
316  * Returns 0 since it always succeeds.
317  */
318 static int movn_func(struct pt_regs *regs, u32 ir)
319 {
320 	if (((regs->regs[MIPSInst_RT(ir)]) != 0) && MIPSInst_RD(ir))
321 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
322 	MIPS_R2_STATS(movs);
323 
324 	return 0;
325 }
326 
327 /**
328  * mfhi_func - Emulate a MFHI instruction
329  * @regs: Process register set
330  * @ir: Instruction
331  *
332  * Returns 0 since it always succeeds.
333  */
334 static int mfhi_func(struct pt_regs *regs, u32 ir)
335 {
336 	if (MIPSInst_RD(ir))
337 		regs->regs[MIPSInst_RD(ir)] = regs->hi;
338 
339 	MIPS_R2_STATS(hilo);
340 
341 	return 0;
342 }
343 
344 /**
345  * mthi_func - Emulate a MTHI instruction
346  * @regs: Process register set
347  * @ir: Instruction
348  *
349  * Returns 0 since it always succeeds.
350  */
351 static int mthi_func(struct pt_regs *regs, u32 ir)
352 {
353 	regs->hi = regs->regs[MIPSInst_RS(ir)];
354 
355 	MIPS_R2_STATS(hilo);
356 
357 	return 0;
358 }
359 
360 /**
361  * mflo_func - Emulate a MFLO instruction
362  * @regs: Process register set
363  * @ir: Instruction
364  *
365  * Returns 0 since it always succeeds.
366  */
367 static int mflo_func(struct pt_regs *regs, u32 ir)
368 {
369 	if (MIPSInst_RD(ir))
370 		regs->regs[MIPSInst_RD(ir)] = regs->lo;
371 
372 	MIPS_R2_STATS(hilo);
373 
374 	return 0;
375 }
376 
377 /**
378  * mtlo_func - Emulate a MTLO instruction
379  * @regs: Process register set
380  * @ir: Instruction
381  *
382  * Returns 0 since it always succeeds.
383  */
384 static int mtlo_func(struct pt_regs *regs, u32 ir)
385 {
386 	regs->lo = regs->regs[MIPSInst_RS(ir)];
387 
388 	MIPS_R2_STATS(hilo);
389 
390 	return 0;
391 }
392 
393 /**
394  * mult_func - Emulate a MULT instruction
395  * @regs: Process register set
396  * @ir: Instruction
397  *
398  * Returns 0 since it always succeeds.
399  */
400 static int mult_func(struct pt_regs *regs, u32 ir)
401 {
402 	s64 res;
403 	s32 rt, rs;
404 
405 	rt = regs->regs[MIPSInst_RT(ir)];
406 	rs = regs->regs[MIPSInst_RS(ir)];
407 	res = (s64)rt * (s64)rs;
408 
409 	rs = res;
410 	regs->lo = (s64)rs;
411 	rt = res >> 32;
412 	res = (s64)rt;
413 	regs->hi = res;
414 
415 	MIPS_R2_STATS(muls);
416 
417 	return 0;
418 }
419 
420 /**
421  * multu_func - Emulate a MULTU instruction
422  * @regs: Process register set
423  * @ir: Instruction
424  *
425  * Returns 0 since it always succeeds.
426  */
427 static int multu_func(struct pt_regs *regs, u32 ir)
428 {
429 	u64 res;
430 	u32 rt, rs;
431 
432 	rt = regs->regs[MIPSInst_RT(ir)];
433 	rs = regs->regs[MIPSInst_RS(ir)];
434 	res = (u64)rt * (u64)rs;
435 	rt = res;
436 	regs->lo = (s64)rt;
437 	regs->hi = (s64)(res >> 32);
438 
439 	MIPS_R2_STATS(muls);
440 
441 	return 0;
442 }
443 
444 /**
445  * div_func - Emulate a DIV instruction
446  * @regs: Process register set
447  * @ir: Instruction
448  *
449  * Returns 0 since it always succeeds.
450  */
451 static int div_func(struct pt_regs *regs, u32 ir)
452 {
453 	s32 rt, rs;
454 
455 	rt = regs->regs[MIPSInst_RT(ir)];
456 	rs = regs->regs[MIPSInst_RS(ir)];
457 
458 	regs->lo = (s64)(rs / rt);
459 	regs->hi = (s64)(rs % rt);
460 
461 	MIPS_R2_STATS(divs);
462 
463 	return 0;
464 }
465 
466 /**
467  * divu_func - Emulate a DIVU instruction
468  * @regs: Process register set
469  * @ir: Instruction
470  *
471  * Returns 0 since it always succeeds.
472  */
473 static int divu_func(struct pt_regs *regs, u32 ir)
474 {
475 	u32 rt, rs;
476 
477 	rt = regs->regs[MIPSInst_RT(ir)];
478 	rs = regs->regs[MIPSInst_RS(ir)];
479 
480 	regs->lo = (s64)(rs / rt);
481 	regs->hi = (s64)(rs % rt);
482 
483 	MIPS_R2_STATS(divs);
484 
485 	return 0;
486 }
487 
488 /**
489  * dmult_func - Emulate a DMULT instruction
490  * @regs: Process register set
491  * @ir: Instruction
492  *
493  * Returns 0 on success or SIGILL for 32-bit kernels.
494  */
495 static int dmult_func(struct pt_regs *regs, u32 ir)
496 {
497 	s64 res;
498 	s64 rt, rs;
499 
500 	if (IS_ENABLED(CONFIG_32BIT))
501 		return SIGILL;
502 
503 	rt = regs->regs[MIPSInst_RT(ir)];
504 	rs = regs->regs[MIPSInst_RS(ir)];
505 	res = rt * rs;
506 
507 	regs->lo = res;
508 	__asm__ __volatile__(
509 		"dmuh %0, %1, %2\t\n"
510 		: "=r"(res)
511 		: "r"(rt), "r"(rs));
512 
513 	regs->hi = res;
514 
515 	MIPS_R2_STATS(muls);
516 
517 	return 0;
518 }
519 
520 /**
521  * dmultu_func - Emulate a DMULTU instruction
522  * @regs: Process register set
523  * @ir: Instruction
524  *
525  * Returns 0 on success or SIGILL for 32-bit kernels.
526  */
527 static int dmultu_func(struct pt_regs *regs, u32 ir)
528 {
529 	u64 res;
530 	u64 rt, rs;
531 
532 	if (IS_ENABLED(CONFIG_32BIT))
533 		return SIGILL;
534 
535 	rt = regs->regs[MIPSInst_RT(ir)];
536 	rs = regs->regs[MIPSInst_RS(ir)];
537 	res = rt * rs;
538 
539 	regs->lo = res;
540 	__asm__ __volatile__(
541 		"dmuhu %0, %1, %2\t\n"
542 		: "=r"(res)
543 		: "r"(rt), "r"(rs));
544 
545 	regs->hi = res;
546 
547 	MIPS_R2_STATS(muls);
548 
549 	return 0;
550 }
551 
552 /**
553  * ddiv_func - Emulate a DDIV instruction
554  * @regs: Process register set
555  * @ir: Instruction
556  *
557  * Returns 0 on success or SIGILL for 32-bit kernels.
558  */
559 static int ddiv_func(struct pt_regs *regs, u32 ir)
560 {
561 	s64 rt, rs;
562 
563 	if (IS_ENABLED(CONFIG_32BIT))
564 		return SIGILL;
565 
566 	rt = regs->regs[MIPSInst_RT(ir)];
567 	rs = regs->regs[MIPSInst_RS(ir)];
568 
569 	regs->lo = rs / rt;
570 	regs->hi = rs % rt;
571 
572 	MIPS_R2_STATS(divs);
573 
574 	return 0;
575 }
576 
577 /**
578  * ddivu_func - Emulate a DDIVU instruction
579  * @regs: Process register set
580  * @ir: Instruction
581  *
582  * Returns 0 on success or SIGILL for 32-bit kernels.
583  */
584 static int ddivu_func(struct pt_regs *regs, u32 ir)
585 {
586 	u64 rt, rs;
587 
588 	if (IS_ENABLED(CONFIG_32BIT))
589 		return SIGILL;
590 
591 	rt = regs->regs[MIPSInst_RT(ir)];
592 	rs = regs->regs[MIPSInst_RS(ir)];
593 
594 	regs->lo = rs / rt;
595 	regs->hi = rs % rt;
596 
597 	MIPS_R2_STATS(divs);
598 
599 	return 0;
600 }
601 
602 /* R6 removed instructions for the SPECIAL opcode */
603 static struct r2_decoder_table spec_op_table[] = {
604 	{ 0xfc1ff83f, 0x00000008, jr_func },
605 	{ 0xfc00ffff, 0x00000018, mult_func },
606 	{ 0xfc00ffff, 0x00000019, multu_func },
607 	{ 0xfc00ffff, 0x0000001c, dmult_func },
608 	{ 0xfc00ffff, 0x0000001d, dmultu_func },
609 	{ 0xffff07ff, 0x00000010, mfhi_func },
610 	{ 0xfc1fffff, 0x00000011, mthi_func },
611 	{ 0xffff07ff, 0x00000012, mflo_func },
612 	{ 0xfc1fffff, 0x00000013, mtlo_func },
613 	{ 0xfc0307ff, 0x00000001, movf_func },
614 	{ 0xfc0307ff, 0x00010001, movt_func },
615 	{ 0xfc0007ff, 0x0000000a, movz_func },
616 	{ 0xfc0007ff, 0x0000000b, movn_func },
617 	{ 0xfc00ffff, 0x0000001a, div_func },
618 	{ 0xfc00ffff, 0x0000001b, divu_func },
619 	{ 0xfc00ffff, 0x0000001e, ddiv_func },
620 	{ 0xfc00ffff, 0x0000001f, ddivu_func },
621 	{}
622 };
623 
624 /**
625  * madd_func - Emulate a MADD instruction
626  * @regs: Process register set
627  * @ir: Instruction
628  *
629  * Returns 0 since it always succeeds.
630  */
631 static int madd_func(struct pt_regs *regs, u32 ir)
632 {
633 	s64 res;
634 	s32 rt, rs;
635 
636 	rt = regs->regs[MIPSInst_RT(ir)];
637 	rs = regs->regs[MIPSInst_RS(ir)];
638 	res = (s64)rt * (s64)rs;
639 	rt = regs->hi;
640 	rs = regs->lo;
641 	res += ((((s64)rt) << 32) | (u32)rs);
642 
643 	rt = res;
644 	regs->lo = (s64)rt;
645 	rs = res >> 32;
646 	regs->hi = (s64)rs;
647 
648 	MIPS_R2_STATS(dsps);
649 
650 	return 0;
651 }
652 
653 /**
654  * maddu_func - Emulate a MADDU instruction
655  * @regs: Process register set
656  * @ir: Instruction
657  *
658  * Returns 0 since it always succeeds.
659  */
660 static int maddu_func(struct pt_regs *regs, u32 ir)
661 {
662 	u64 res;
663 	u32 rt, rs;
664 
665 	rt = regs->regs[MIPSInst_RT(ir)];
666 	rs = regs->regs[MIPSInst_RS(ir)];
667 	res = (u64)rt * (u64)rs;
668 	rt = regs->hi;
669 	rs = regs->lo;
670 	res += ((((s64)rt) << 32) | (u32)rs);
671 
672 	rt = res;
673 	regs->lo = (s64)rt;
674 	rs = res >> 32;
675 	regs->hi = (s64)rs;
676 
677 	MIPS_R2_STATS(dsps);
678 
679 	return 0;
680 }
681 
682 /**
683  * msub_func - Emulate a MSUB instruction
684  * @regs: Process register set
685  * @ir: Instruction
686  *
687  * Returns 0 since it always succeeds.
688  */
689 static int msub_func(struct pt_regs *regs, u32 ir)
690 {
691 	s64 res;
692 	s32 rt, rs;
693 
694 	rt = regs->regs[MIPSInst_RT(ir)];
695 	rs = regs->regs[MIPSInst_RS(ir)];
696 	res = (s64)rt * (s64)rs;
697 	rt = regs->hi;
698 	rs = regs->lo;
699 	res = ((((s64)rt) << 32) | (u32)rs) - res;
700 
701 	rt = res;
702 	regs->lo = (s64)rt;
703 	rs = res >> 32;
704 	regs->hi = (s64)rs;
705 
706 	MIPS_R2_STATS(dsps);
707 
708 	return 0;
709 }
710 
711 /**
712  * msubu_func - Emulate a MSUBU instruction
713  * @regs: Process register set
714  * @ir: Instruction
715  *
716  * Returns 0 since it always succeeds.
717  */
718 static int msubu_func(struct pt_regs *regs, u32 ir)
719 {
720 	u64 res;
721 	u32 rt, rs;
722 
723 	rt = regs->regs[MIPSInst_RT(ir)];
724 	rs = regs->regs[MIPSInst_RS(ir)];
725 	res = (u64)rt * (u64)rs;
726 	rt = regs->hi;
727 	rs = regs->lo;
728 	res = ((((s64)rt) << 32) | (u32)rs) - res;
729 
730 	rt = res;
731 	regs->lo = (s64)rt;
732 	rs = res >> 32;
733 	regs->hi = (s64)rs;
734 
735 	MIPS_R2_STATS(dsps);
736 
737 	return 0;
738 }
739 
740 /**
741  * mul_func - Emulate a MUL instruction
742  * @regs: Process register set
743  * @ir: Instruction
744  *
745  * Returns 0 since it always succeeds.
746  */
747 static int mul_func(struct pt_regs *regs, u32 ir)
748 {
749 	s64 res;
750 	s32 rt, rs;
751 
752 	if (!MIPSInst_RD(ir))
753 		return 0;
754 	rt = regs->regs[MIPSInst_RT(ir)];
755 	rs = regs->regs[MIPSInst_RS(ir)];
756 	res = (s64)rt * (s64)rs;
757 
758 	rs = res;
759 	regs->regs[MIPSInst_RD(ir)] = (s64)rs;
760 
761 	MIPS_R2_STATS(muls);
762 
763 	return 0;
764 }
765 
766 /**
767  * clz_func - Emulate a CLZ instruction
768  * @regs: Process register set
769  * @ir: Instruction
770  *
771  * Returns 0 since it always succeeds.
772  */
773 static int clz_func(struct pt_regs *regs, u32 ir)
774 {
775 	u32 res;
776 	u32 rs;
777 
778 	if (!MIPSInst_RD(ir))
779 		return 0;
780 
781 	rs = regs->regs[MIPSInst_RS(ir)];
782 	__asm__ __volatile__("clz %0, %1" : "=r"(res) : "r"(rs));
783 	regs->regs[MIPSInst_RD(ir)] = res;
784 
785 	MIPS_R2_STATS(bops);
786 
787 	return 0;
788 }
789 
790 /**
791  * clo_func - Emulate a CLO instruction
792  * @regs: Process register set
793  * @ir: Instruction
794  *
795  * Returns 0 since it always succeeds.
796  */
797 
798 static int clo_func(struct pt_regs *regs, u32 ir)
799 {
800 	u32 res;
801 	u32 rs;
802 
803 	if (!MIPSInst_RD(ir))
804 		return 0;
805 
806 	rs = regs->regs[MIPSInst_RS(ir)];
807 	__asm__ __volatile__("clo %0, %1" : "=r"(res) : "r"(rs));
808 	regs->regs[MIPSInst_RD(ir)] = res;
809 
810 	MIPS_R2_STATS(bops);
811 
812 	return 0;
813 }
814 
815 /**
816  * dclz_func - Emulate a DCLZ instruction
817  * @regs: Process register set
818  * @ir: Instruction
819  *
820  * Returns 0 since it always succeeds.
821  */
822 static int dclz_func(struct pt_regs *regs, u32 ir)
823 {
824 	u64 res;
825 	u64 rs;
826 
827 	if (IS_ENABLED(CONFIG_32BIT))
828 		return SIGILL;
829 
830 	if (!MIPSInst_RD(ir))
831 		return 0;
832 
833 	rs = regs->regs[MIPSInst_RS(ir)];
834 	__asm__ __volatile__("dclz %0, %1" : "=r"(res) : "r"(rs));
835 	regs->regs[MIPSInst_RD(ir)] = res;
836 
837 	MIPS_R2_STATS(bops);
838 
839 	return 0;
840 }
841 
842 /**
843  * dclo_func - Emulate a DCLO instruction
844  * @regs: Process register set
845  * @ir: Instruction
846  *
847  * Returns 0 since it always succeeds.
848  */
849 static int dclo_func(struct pt_regs *regs, u32 ir)
850 {
851 	u64 res;
852 	u64 rs;
853 
854 	if (IS_ENABLED(CONFIG_32BIT))
855 		return SIGILL;
856 
857 	if (!MIPSInst_RD(ir))
858 		return 0;
859 
860 	rs = regs->regs[MIPSInst_RS(ir)];
861 	__asm__ __volatile__("dclo %0, %1" : "=r"(res) : "r"(rs));
862 	regs->regs[MIPSInst_RD(ir)] = res;
863 
864 	MIPS_R2_STATS(bops);
865 
866 	return 0;
867 }
868 
869 /* R6 removed instructions for the SPECIAL2 opcode */
870 static struct r2_decoder_table spec2_op_table[] = {
871 	{ 0xfc00ffff, 0x70000000, madd_func },
872 	{ 0xfc00ffff, 0x70000001, maddu_func },
873 	{ 0xfc0007ff, 0x70000002, mul_func },
874 	{ 0xfc00ffff, 0x70000004, msub_func },
875 	{ 0xfc00ffff, 0x70000005, msubu_func },
876 	{ 0xfc0007ff, 0x70000020, clz_func },
877 	{ 0xfc0007ff, 0x70000021, clo_func },
878 	{ 0xfc0007ff, 0x70000024, dclz_func },
879 	{ 0xfc0007ff, 0x70000025, dclo_func },
880 	{ }
881 };
882 
883 static inline int mipsr2_find_op_func(struct pt_regs *regs, u32 inst,
884 				      struct r2_decoder_table *table)
885 {
886 	struct r2_decoder_table *p;
887 	int err;
888 
889 	for (p = table; p->func; p++) {
890 		if ((inst & p->mask) == p->code) {
891 			err = (p->func)(regs, inst);
892 			return err;
893 		}
894 	}
895 	return SIGILL;
896 }
897 
898 /**
899  * mipsr2_decoder: Decode and emulate a MIPS R2 instruction
900  * @regs: Process register set
901  * @inst: Instruction to decode and emulate
902  * @fcr31: Floating Point Control and Status Register Cause bits returned
903  */
904 int mipsr2_decoder(struct pt_regs *regs, u32 inst, unsigned long *fcr31)
905 {
906 	int err = 0;
907 	unsigned long vaddr;
908 	u32 nir;
909 	unsigned long cpc, epc, nepc, r31, res, rs, rt;
910 
911 	void __user *fault_addr = NULL;
912 	int pass = 0;
913 
914 repeat:
915 	r31 = regs->regs[31];
916 	epc = regs->cp0_epc;
917 	err = compute_return_epc(regs);
918 	if (err < 0) {
919 		BUG();
920 		return SIGEMT;
921 	}
922 	pr_debug("Emulating the 0x%08x R2 instruction @ 0x%08lx (pass=%d))\n",
923 		 inst, epc, pass);
924 
925 	switch (MIPSInst_OPCODE(inst)) {
926 	case spec_op:
927 		err = mipsr2_find_op_func(regs, inst, spec_op_table);
928 		if (err < 0) {
929 			/* FPU instruction under JR */
930 			regs->cp0_cause |= CAUSEF_BD;
931 			goto fpu_emul;
932 		}
933 		break;
934 	case spec2_op:
935 		err = mipsr2_find_op_func(regs, inst, spec2_op_table);
936 		break;
937 	case bcond_op:
938 		rt = MIPSInst_RT(inst);
939 		rs = MIPSInst_RS(inst);
940 		switch (rt) {
941 		case tgei_op:
942 			if ((long)regs->regs[rs] >= MIPSInst_SIMM(inst))
943 				do_trap_or_bp(regs, 0, 0, "TGEI");
944 
945 			MIPS_R2_STATS(traps);
946 
947 			break;
948 		case tgeiu_op:
949 			if (regs->regs[rs] >= MIPSInst_UIMM(inst))
950 				do_trap_or_bp(regs, 0, 0, "TGEIU");
951 
952 			MIPS_R2_STATS(traps);
953 
954 			break;
955 		case tlti_op:
956 			if ((long)regs->regs[rs] < MIPSInst_SIMM(inst))
957 				do_trap_or_bp(regs, 0, 0, "TLTI");
958 
959 			MIPS_R2_STATS(traps);
960 
961 			break;
962 		case tltiu_op:
963 			if (regs->regs[rs] < MIPSInst_UIMM(inst))
964 				do_trap_or_bp(regs, 0, 0, "TLTIU");
965 
966 			MIPS_R2_STATS(traps);
967 
968 			break;
969 		case teqi_op:
970 			if (regs->regs[rs] == MIPSInst_SIMM(inst))
971 				do_trap_or_bp(regs, 0, 0, "TEQI");
972 
973 			MIPS_R2_STATS(traps);
974 
975 			break;
976 		case tnei_op:
977 			if (regs->regs[rs] != MIPSInst_SIMM(inst))
978 				do_trap_or_bp(regs, 0, 0, "TNEI");
979 
980 			MIPS_R2_STATS(traps);
981 
982 			break;
983 		case bltzl_op:
984 		case bgezl_op:
985 		case bltzall_op:
986 		case bgezall_op:
987 			if (delay_slot(regs)) {
988 				err = SIGILL;
989 				break;
990 			}
991 			regs->regs[31] = r31;
992 			regs->cp0_epc = epc;
993 			err = __compute_return_epc(regs);
994 			if (err < 0)
995 				return SIGEMT;
996 			if (err != BRANCH_LIKELY_TAKEN)
997 				break;
998 			cpc = regs->cp0_epc;
999 			nepc = epc + 4;
1000 			err = __get_user(nir, (u32 __user *)nepc);
1001 			if (err) {
1002 				err = SIGSEGV;
1003 				break;
1004 			}
1005 			/*
1006 			 * This will probably be optimized away when
1007 			 * CONFIG_DEBUG_FS is not enabled
1008 			 */
1009 			switch (rt) {
1010 			case bltzl_op:
1011 				MIPS_R2BR_STATS(bltzl);
1012 				break;
1013 			case bgezl_op:
1014 				MIPS_R2BR_STATS(bgezl);
1015 				break;
1016 			case bltzall_op:
1017 				MIPS_R2BR_STATS(bltzall);
1018 				break;
1019 			case bgezall_op:
1020 				MIPS_R2BR_STATS(bgezall);
1021 				break;
1022 			}
1023 
1024 			switch (MIPSInst_OPCODE(nir)) {
1025 			case cop1_op:
1026 			case cop1x_op:
1027 			case lwc1_op:
1028 			case swc1_op:
1029 				regs->cp0_cause |= CAUSEF_BD;
1030 				goto fpu_emul;
1031 			}
1032 			if (nir) {
1033 				err = mipsr6_emul(regs, nir);
1034 				if (err > 0) {
1035 					err = mips_dsemul(regs, nir, epc, cpc);
1036 					if (err == SIGILL)
1037 						err = SIGEMT;
1038 					MIPS_R2_STATS(dsemul);
1039 				}
1040 			}
1041 			break;
1042 		case bltzal_op:
1043 		case bgezal_op:
1044 			if (delay_slot(regs)) {
1045 				err = SIGILL;
1046 				break;
1047 			}
1048 			regs->regs[31] = r31;
1049 			regs->cp0_epc = epc;
1050 			err = __compute_return_epc(regs);
1051 			if (err < 0)
1052 				return SIGEMT;
1053 			cpc = regs->cp0_epc;
1054 			nepc = epc + 4;
1055 			err = __get_user(nir, (u32 __user *)nepc);
1056 			if (err) {
1057 				err = SIGSEGV;
1058 				break;
1059 			}
1060 			/*
1061 			 * This will probably be optimized away when
1062 			 * CONFIG_DEBUG_FS is not enabled
1063 			 */
1064 			switch (rt) {
1065 			case bltzal_op:
1066 				MIPS_R2BR_STATS(bltzal);
1067 				break;
1068 			case bgezal_op:
1069 				MIPS_R2BR_STATS(bgezal);
1070 				break;
1071 			}
1072 
1073 			switch (MIPSInst_OPCODE(nir)) {
1074 			case cop1_op:
1075 			case cop1x_op:
1076 			case lwc1_op:
1077 			case swc1_op:
1078 				regs->cp0_cause |= CAUSEF_BD;
1079 				goto fpu_emul;
1080 			}
1081 			if (nir) {
1082 				err = mipsr6_emul(regs, nir);
1083 				if (err > 0) {
1084 					err = mips_dsemul(regs, nir, epc, cpc);
1085 					if (err == SIGILL)
1086 						err = SIGEMT;
1087 					MIPS_R2_STATS(dsemul);
1088 				}
1089 			}
1090 			break;
1091 		default:
1092 			regs->regs[31] = r31;
1093 			regs->cp0_epc = epc;
1094 			err = SIGILL;
1095 			break;
1096 		}
1097 		break;
1098 
1099 	case beql_op:
1100 	case bnel_op:
1101 	case blezl_op:
1102 	case bgtzl_op:
1103 		if (delay_slot(regs)) {
1104 			err = SIGILL;
1105 			break;
1106 		}
1107 		regs->regs[31] = r31;
1108 		regs->cp0_epc = epc;
1109 		err = __compute_return_epc(regs);
1110 		if (err < 0)
1111 			return SIGEMT;
1112 		if (err != BRANCH_LIKELY_TAKEN)
1113 			break;
1114 		cpc = regs->cp0_epc;
1115 		nepc = epc + 4;
1116 		err = __get_user(nir, (u32 __user *)nepc);
1117 		if (err) {
1118 			err = SIGSEGV;
1119 			break;
1120 		}
1121 		/*
1122 		 * This will probably be optimized away when
1123 		 * CONFIG_DEBUG_FS is not enabled
1124 		 */
1125 		switch (MIPSInst_OPCODE(inst)) {
1126 		case beql_op:
1127 			MIPS_R2BR_STATS(beql);
1128 			break;
1129 		case bnel_op:
1130 			MIPS_R2BR_STATS(bnel);
1131 			break;
1132 		case blezl_op:
1133 			MIPS_R2BR_STATS(blezl);
1134 			break;
1135 		case bgtzl_op:
1136 			MIPS_R2BR_STATS(bgtzl);
1137 			break;
1138 		}
1139 
1140 		switch (MIPSInst_OPCODE(nir)) {
1141 		case cop1_op:
1142 		case cop1x_op:
1143 		case lwc1_op:
1144 		case swc1_op:
1145 			regs->cp0_cause |= CAUSEF_BD;
1146 			goto fpu_emul;
1147 		}
1148 		if (nir) {
1149 			err = mipsr6_emul(regs, nir);
1150 			if (err > 0) {
1151 				err = mips_dsemul(regs, nir, epc, cpc);
1152 				if (err == SIGILL)
1153 					err = SIGEMT;
1154 				MIPS_R2_STATS(dsemul);
1155 			}
1156 		}
1157 		break;
1158 	case lwc1_op:
1159 	case swc1_op:
1160 	case cop1_op:
1161 	case cop1x_op:
1162 fpu_emul:
1163 		regs->regs[31] = r31;
1164 		regs->cp0_epc = epc;
1165 		if (!used_math()) {     /* First time FPU user.  */
1166 			preempt_disable();
1167 			err = init_fpu();
1168 			preempt_enable();
1169 			set_used_math();
1170 		}
1171 		lose_fpu(1);    /* Save FPU state for the emulator. */
1172 
1173 		err = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
1174 					       &fault_addr);
1175 
1176 		/*
1177 		 * We can't allow the emulated instruction to leave any
1178 		 * enabled Cause bits set in $fcr31.
1179 		 */
1180 		*fcr31 = res = mask_fcr31_x(current->thread.fpu.fcr31);
1181 		current->thread.fpu.fcr31 &= ~res;
1182 
1183 		/*
1184 		 * this is a tricky issue - lose_fpu() uses LL/SC atomics
1185 		 * if FPU is owned and effectively cancels user level LL/SC.
1186 		 * So, it could be logical to don't restore FPU ownership here.
1187 		 * But the sequence of multiple FPU instructions is much much
1188 		 * more often than LL-FPU-SC and I prefer loop here until
1189 		 * next scheduler cycle cancels FPU ownership
1190 		 */
1191 		own_fpu(1);	/* Restore FPU state. */
1192 
1193 		if (err)
1194 			current->thread.cp0_baduaddr = (unsigned long)fault_addr;
1195 
1196 		MIPS_R2_STATS(fpus);
1197 
1198 		break;
1199 
1200 	case lwl_op:
1201 		rt = regs->regs[MIPSInst_RT(inst)];
1202 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1203 		if (!access_ok(VERIFY_READ, vaddr, 4)) {
1204 			current->thread.cp0_baduaddr = vaddr;
1205 			err = SIGSEGV;
1206 			break;
1207 		}
1208 		__asm__ __volatile__(
1209 			"	.set	push\n"
1210 			"	.set	reorder\n"
1211 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1212 			"1:"	LB	"%1, 0(%2)\n"
1213 				INS	"%0, %1, 24, 8\n"
1214 			"	andi	%1, %2, 0x3\n"
1215 			"	beq	$0, %1, 9f\n"
1216 				ADDIU	"%2, %2, -1\n"
1217 			"2:"	LB	"%1, 0(%2)\n"
1218 				INS	"%0, %1, 16, 8\n"
1219 			"	andi	%1, %2, 0x3\n"
1220 			"	beq	$0, %1, 9f\n"
1221 				ADDIU	"%2, %2, -1\n"
1222 			"3:"	LB	"%1, 0(%2)\n"
1223 				INS	"%0, %1, 8, 8\n"
1224 			"	andi	%1, %2, 0x3\n"
1225 			"	beq	$0, %1, 9f\n"
1226 				ADDIU	"%2, %2, -1\n"
1227 			"4:"	LB	"%1, 0(%2)\n"
1228 				INS	"%0, %1, 0, 8\n"
1229 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1230 			"1:"	LB	"%1, 0(%2)\n"
1231 				INS	"%0, %1, 24, 8\n"
1232 				ADDIU	"%2, %2, 1\n"
1233 			"	andi	%1, %2, 0x3\n"
1234 			"	beq	$0, %1, 9f\n"
1235 			"2:"	LB	"%1, 0(%2)\n"
1236 				INS	"%0, %1, 16, 8\n"
1237 				ADDIU	"%2, %2, 1\n"
1238 			"	andi	%1, %2, 0x3\n"
1239 			"	beq	$0, %1, 9f\n"
1240 			"3:"	LB	"%1, 0(%2)\n"
1241 				INS	"%0, %1, 8, 8\n"
1242 				ADDIU	"%2, %2, 1\n"
1243 			"	andi	%1, %2, 0x3\n"
1244 			"	beq	$0, %1, 9f\n"
1245 			"4:"	LB	"%1, 0(%2)\n"
1246 				INS	"%0, %1, 0, 8\n"
1247 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1248 			"9:	sll	%0, %0, 0\n"
1249 			"10:\n"
1250 			"	.insn\n"
1251 			"	.section	.fixup,\"ax\"\n"
1252 			"8:	li	%3,%4\n"
1253 			"	j	10b\n"
1254 			"	.previous\n"
1255 			"	.section	__ex_table,\"a\"\n"
1256 			STR(PTR) " 1b,8b\n"
1257 			STR(PTR) " 2b,8b\n"
1258 			STR(PTR) " 3b,8b\n"
1259 			STR(PTR) " 4b,8b\n"
1260 			"	.previous\n"
1261 			"	.set	pop\n"
1262 			: "+&r"(rt), "=&r"(rs),
1263 			  "+&r"(vaddr), "+&r"(err)
1264 			: "i"(SIGSEGV));
1265 
1266 		if (MIPSInst_RT(inst) && !err)
1267 			regs->regs[MIPSInst_RT(inst)] = rt;
1268 
1269 		MIPS_R2_STATS(loads);
1270 
1271 		break;
1272 
1273 	case lwr_op:
1274 		rt = regs->regs[MIPSInst_RT(inst)];
1275 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1276 		if (!access_ok(VERIFY_READ, vaddr, 4)) {
1277 			current->thread.cp0_baduaddr = vaddr;
1278 			err = SIGSEGV;
1279 			break;
1280 		}
1281 		__asm__ __volatile__(
1282 			"       .set	push\n"
1283 			"       .set	reorder\n"
1284 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1285 			"1:"    LB	"%1, 0(%2)\n"
1286 				INS	"%0, %1, 0, 8\n"
1287 				ADDIU	"%2, %2, 1\n"
1288 			"       andi	%1, %2, 0x3\n"
1289 			"       beq	$0, %1, 9f\n"
1290 			"2:"    LB	"%1, 0(%2)\n"
1291 				INS	"%0, %1, 8, 8\n"
1292 				ADDIU	"%2, %2, 1\n"
1293 			"       andi	%1, %2, 0x3\n"
1294 			"       beq	$0, %1, 9f\n"
1295 			"3:"    LB	"%1, 0(%2)\n"
1296 				INS	"%0, %1, 16, 8\n"
1297 				ADDIU	"%2, %2, 1\n"
1298 			"       andi	%1, %2, 0x3\n"
1299 			"       beq	$0, %1, 9f\n"
1300 			"4:"    LB	"%1, 0(%2)\n"
1301 				INS	"%0, %1, 24, 8\n"
1302 			"       sll	%0, %0, 0\n"
1303 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1304 			"1:"    LB	"%1, 0(%2)\n"
1305 				INS	"%0, %1, 0, 8\n"
1306 			"       andi	%1, %2, 0x3\n"
1307 			"       beq	$0, %1, 9f\n"
1308 				ADDIU	"%2, %2, -1\n"
1309 			"2:"    LB	"%1, 0(%2)\n"
1310 				INS	"%0, %1, 8, 8\n"
1311 			"       andi	%1, %2, 0x3\n"
1312 			"       beq	$0, %1, 9f\n"
1313 				ADDIU	"%2, %2, -1\n"
1314 			"3:"    LB	"%1, 0(%2)\n"
1315 				INS	"%0, %1, 16, 8\n"
1316 			"       andi	%1, %2, 0x3\n"
1317 			"       beq	$0, %1, 9f\n"
1318 				ADDIU	"%2, %2, -1\n"
1319 			"4:"    LB	"%1, 0(%2)\n"
1320 				INS	"%0, %1, 24, 8\n"
1321 			"       sll	%0, %0, 0\n"
1322 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1323 			"9:\n"
1324 			"10:\n"
1325 			"	.insn\n"
1326 			"	.section	.fixup,\"ax\"\n"
1327 			"8:	li	%3,%4\n"
1328 			"	j	10b\n"
1329 			"       .previous\n"
1330 			"	.section	__ex_table,\"a\"\n"
1331 			STR(PTR) " 1b,8b\n"
1332 			STR(PTR) " 2b,8b\n"
1333 			STR(PTR) " 3b,8b\n"
1334 			STR(PTR) " 4b,8b\n"
1335 			"	.previous\n"
1336 			"	.set	pop\n"
1337 			: "+&r"(rt), "=&r"(rs),
1338 			  "+&r"(vaddr), "+&r"(err)
1339 			: "i"(SIGSEGV));
1340 		if (MIPSInst_RT(inst) && !err)
1341 			regs->regs[MIPSInst_RT(inst)] = rt;
1342 
1343 		MIPS_R2_STATS(loads);
1344 
1345 		break;
1346 
1347 	case swl_op:
1348 		rt = regs->regs[MIPSInst_RT(inst)];
1349 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1350 		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
1351 			current->thread.cp0_baduaddr = vaddr;
1352 			err = SIGSEGV;
1353 			break;
1354 		}
1355 		__asm__ __volatile__(
1356 			"	.set	push\n"
1357 			"	.set	reorder\n"
1358 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1359 				EXT	"%1, %0, 24, 8\n"
1360 			"1:"	SB	"%1, 0(%2)\n"
1361 			"	andi	%1, %2, 0x3\n"
1362 			"	beq	$0, %1, 9f\n"
1363 				ADDIU	"%2, %2, -1\n"
1364 				EXT	"%1, %0, 16, 8\n"
1365 			"2:"	SB	"%1, 0(%2)\n"
1366 			"	andi	%1, %2, 0x3\n"
1367 			"	beq	$0, %1, 9f\n"
1368 				ADDIU	"%2, %2, -1\n"
1369 				EXT	"%1, %0, 8, 8\n"
1370 			"3:"	SB	"%1, 0(%2)\n"
1371 			"	andi	%1, %2, 0x3\n"
1372 			"	beq	$0, %1, 9f\n"
1373 				ADDIU	"%2, %2, -1\n"
1374 				EXT	"%1, %0, 0, 8\n"
1375 			"4:"	SB	"%1, 0(%2)\n"
1376 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1377 				EXT	"%1, %0, 24, 8\n"
1378 			"1:"	SB	"%1, 0(%2)\n"
1379 				ADDIU	"%2, %2, 1\n"
1380 			"	andi	%1, %2, 0x3\n"
1381 			"	beq	$0, %1, 9f\n"
1382 				EXT	"%1, %0, 16, 8\n"
1383 			"2:"	SB	"%1, 0(%2)\n"
1384 				ADDIU	"%2, %2, 1\n"
1385 			"	andi	%1, %2, 0x3\n"
1386 			"	beq	$0, %1, 9f\n"
1387 				EXT	"%1, %0, 8, 8\n"
1388 			"3:"	SB	"%1, 0(%2)\n"
1389 				ADDIU	"%2, %2, 1\n"
1390 			"	andi	%1, %2, 0x3\n"
1391 			"	beq	$0, %1, 9f\n"
1392 				EXT	"%1, %0, 0, 8\n"
1393 			"4:"	SB	"%1, 0(%2)\n"
1394 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1395 			"9:\n"
1396 			"	.insn\n"
1397 			"       .section        .fixup,\"ax\"\n"
1398 			"8:	li	%3,%4\n"
1399 			"	j	9b\n"
1400 			"	.previous\n"
1401 			"	.section        __ex_table,\"a\"\n"
1402 			STR(PTR) " 1b,8b\n"
1403 			STR(PTR) " 2b,8b\n"
1404 			STR(PTR) " 3b,8b\n"
1405 			STR(PTR) " 4b,8b\n"
1406 			"	.previous\n"
1407 			"	.set	pop\n"
1408 			: "+&r"(rt), "=&r"(rs),
1409 			  "+&r"(vaddr), "+&r"(err)
1410 			: "i"(SIGSEGV)
1411 			: "memory");
1412 
1413 		MIPS_R2_STATS(stores);
1414 
1415 		break;
1416 
1417 	case swr_op:
1418 		rt = regs->regs[MIPSInst_RT(inst)];
1419 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1420 		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
1421 			current->thread.cp0_baduaddr = vaddr;
1422 			err = SIGSEGV;
1423 			break;
1424 		}
1425 		__asm__ __volatile__(
1426 			"	.set	push\n"
1427 			"	.set	reorder\n"
1428 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1429 				EXT	"%1, %0, 0, 8\n"
1430 			"1:"	SB	"%1, 0(%2)\n"
1431 				ADDIU	"%2, %2, 1\n"
1432 			"	andi	%1, %2, 0x3\n"
1433 			"	beq	$0, %1, 9f\n"
1434 				EXT	"%1, %0, 8, 8\n"
1435 			"2:"	SB	"%1, 0(%2)\n"
1436 				ADDIU	"%2, %2, 1\n"
1437 			"	andi	%1, %2, 0x3\n"
1438 			"	beq	$0, %1, 9f\n"
1439 				EXT	"%1, %0, 16, 8\n"
1440 			"3:"	SB	"%1, 0(%2)\n"
1441 				ADDIU	"%2, %2, 1\n"
1442 			"	andi	%1, %2, 0x3\n"
1443 			"	beq	$0, %1, 9f\n"
1444 				EXT	"%1, %0, 24, 8\n"
1445 			"4:"	SB	"%1, 0(%2)\n"
1446 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1447 				EXT	"%1, %0, 0, 8\n"
1448 			"1:"	SB	"%1, 0(%2)\n"
1449 			"	andi	%1, %2, 0x3\n"
1450 			"	beq	$0, %1, 9f\n"
1451 				ADDIU	"%2, %2, -1\n"
1452 				EXT	"%1, %0, 8, 8\n"
1453 			"2:"	SB	"%1, 0(%2)\n"
1454 			"	andi	%1, %2, 0x3\n"
1455 			"	beq	$0, %1, 9f\n"
1456 				ADDIU	"%2, %2, -1\n"
1457 				EXT	"%1, %0, 16, 8\n"
1458 			"3:"	SB	"%1, 0(%2)\n"
1459 			"	andi	%1, %2, 0x3\n"
1460 			"	beq	$0, %1, 9f\n"
1461 				ADDIU	"%2, %2, -1\n"
1462 				EXT	"%1, %0, 24, 8\n"
1463 			"4:"	SB	"%1, 0(%2)\n"
1464 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1465 			"9:\n"
1466 			"	.insn\n"
1467 			"	.section        .fixup,\"ax\"\n"
1468 			"8:	li	%3,%4\n"
1469 			"	j	9b\n"
1470 			"	.previous\n"
1471 			"	.section        __ex_table,\"a\"\n"
1472 			STR(PTR) " 1b,8b\n"
1473 			STR(PTR) " 2b,8b\n"
1474 			STR(PTR) " 3b,8b\n"
1475 			STR(PTR) " 4b,8b\n"
1476 			"	.previous\n"
1477 			"	.set	pop\n"
1478 			: "+&r"(rt), "=&r"(rs),
1479 			  "+&r"(vaddr), "+&r"(err)
1480 			: "i"(SIGSEGV)
1481 			: "memory");
1482 
1483 		MIPS_R2_STATS(stores);
1484 
1485 		break;
1486 
1487 	case ldl_op:
1488 		if (IS_ENABLED(CONFIG_32BIT)) {
1489 		    err = SIGILL;
1490 		    break;
1491 		}
1492 
1493 		rt = regs->regs[MIPSInst_RT(inst)];
1494 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1495 		if (!access_ok(VERIFY_READ, vaddr, 8)) {
1496 			current->thread.cp0_baduaddr = vaddr;
1497 			err = SIGSEGV;
1498 			break;
1499 		}
1500 		__asm__ __volatile__(
1501 			"	.set    push\n"
1502 			"	.set    reorder\n"
1503 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1504 			"1:	lb	%1, 0(%2)\n"
1505 			"	dinsu	%0, %1, 56, 8\n"
1506 			"	andi	%1, %2, 0x7\n"
1507 			"	beq	$0, %1, 9f\n"
1508 			"	daddiu	%2, %2, -1\n"
1509 			"2:	lb	%1, 0(%2)\n"
1510 			"	dinsu	%0, %1, 48, 8\n"
1511 			"	andi	%1, %2, 0x7\n"
1512 			"	beq	$0, %1, 9f\n"
1513 			"	daddiu	%2, %2, -1\n"
1514 			"3:	lb	%1, 0(%2)\n"
1515 			"	dinsu	%0, %1, 40, 8\n"
1516 			"	andi	%1, %2, 0x7\n"
1517 			"	beq	$0, %1, 9f\n"
1518 			"	daddiu	%2, %2, -1\n"
1519 			"4:	lb	%1, 0(%2)\n"
1520 			"	dinsu	%0, %1, 32, 8\n"
1521 			"	andi	%1, %2, 0x7\n"
1522 			"	beq	$0, %1, 9f\n"
1523 			"	daddiu	%2, %2, -1\n"
1524 			"5:	lb	%1, 0(%2)\n"
1525 			"	dins	%0, %1, 24, 8\n"
1526 			"	andi	%1, %2, 0x7\n"
1527 			"	beq	$0, %1, 9f\n"
1528 			"	daddiu	%2, %2, -1\n"
1529 			"6:	lb	%1, 0(%2)\n"
1530 			"	dins	%0, %1, 16, 8\n"
1531 			"	andi	%1, %2, 0x7\n"
1532 			"	beq	$0, %1, 9f\n"
1533 			"	daddiu	%2, %2, -1\n"
1534 			"7:	lb	%1, 0(%2)\n"
1535 			"	dins	%0, %1, 8, 8\n"
1536 			"	andi	%1, %2, 0x7\n"
1537 			"	beq	$0, %1, 9f\n"
1538 			"	daddiu	%2, %2, -1\n"
1539 			"0:	lb	%1, 0(%2)\n"
1540 			"	dins	%0, %1, 0, 8\n"
1541 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1542 			"1:	lb	%1, 0(%2)\n"
1543 			"	dinsu	%0, %1, 56, 8\n"
1544 			"	daddiu	%2, %2, 1\n"
1545 			"	andi	%1, %2, 0x7\n"
1546 			"	beq	$0, %1, 9f\n"
1547 			"2:	lb	%1, 0(%2)\n"
1548 			"	dinsu	%0, %1, 48, 8\n"
1549 			"	daddiu	%2, %2, 1\n"
1550 			"	andi	%1, %2, 0x7\n"
1551 			"	beq	$0, %1, 9f\n"
1552 			"3:	lb	%1, 0(%2)\n"
1553 			"	dinsu	%0, %1, 40, 8\n"
1554 			"	daddiu  %2, %2, 1\n"
1555 			"	andi	%1, %2, 0x7\n"
1556 			"	beq	$0, %1, 9f\n"
1557 			"4:	lb	%1, 0(%2)\n"
1558 			"	dinsu	%0, %1, 32, 8\n"
1559 			"	daddiu	%2, %2, 1\n"
1560 			"	andi	%1, %2, 0x7\n"
1561 			"	beq	$0, %1, 9f\n"
1562 			"5:	lb	%1, 0(%2)\n"
1563 			"	dins	%0, %1, 24, 8\n"
1564 			"	daddiu	%2, %2, 1\n"
1565 			"	andi	%1, %2, 0x7\n"
1566 			"	beq	$0, %1, 9f\n"
1567 			"6:	lb	%1, 0(%2)\n"
1568 			"	dins	%0, %1, 16, 8\n"
1569 			"	daddiu	%2, %2, 1\n"
1570 			"	andi	%1, %2, 0x7\n"
1571 			"	beq	$0, %1, 9f\n"
1572 			"7:	lb	%1, 0(%2)\n"
1573 			"	dins	%0, %1, 8, 8\n"
1574 			"	daddiu	%2, %2, 1\n"
1575 			"	andi	%1, %2, 0x7\n"
1576 			"	beq	$0, %1, 9f\n"
1577 			"0:	lb	%1, 0(%2)\n"
1578 			"	dins	%0, %1, 0, 8\n"
1579 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1580 			"9:\n"
1581 			"	.insn\n"
1582 			"	.section        .fixup,\"ax\"\n"
1583 			"8:	li	%3,%4\n"
1584 			"	j	9b\n"
1585 			"	.previous\n"
1586 			"	.section        __ex_table,\"a\"\n"
1587 			STR(PTR) " 1b,8b\n"
1588 			STR(PTR) " 2b,8b\n"
1589 			STR(PTR) " 3b,8b\n"
1590 			STR(PTR) " 4b,8b\n"
1591 			STR(PTR) " 5b,8b\n"
1592 			STR(PTR) " 6b,8b\n"
1593 			STR(PTR) " 7b,8b\n"
1594 			STR(PTR) " 0b,8b\n"
1595 			"	.previous\n"
1596 			"	.set	pop\n"
1597 			: "+&r"(rt), "=&r"(rs),
1598 			  "+&r"(vaddr), "+&r"(err)
1599 			: "i"(SIGSEGV));
1600 		if (MIPSInst_RT(inst) && !err)
1601 			regs->regs[MIPSInst_RT(inst)] = rt;
1602 
1603 		MIPS_R2_STATS(loads);
1604 		break;
1605 
1606 	case ldr_op:
1607 		if (IS_ENABLED(CONFIG_32BIT)) {
1608 		    err = SIGILL;
1609 		    break;
1610 		}
1611 
1612 		rt = regs->regs[MIPSInst_RT(inst)];
1613 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1614 		if (!access_ok(VERIFY_READ, vaddr, 8)) {
1615 			current->thread.cp0_baduaddr = vaddr;
1616 			err = SIGSEGV;
1617 			break;
1618 		}
1619 		__asm__ __volatile__(
1620 			"	.set    push\n"
1621 			"	.set    reorder\n"
1622 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1623 			"1:	lb      %1, 0(%2)\n"
1624 			"	dins   %0, %1, 0, 8\n"
1625 			"	daddiu  %2, %2, 1\n"
1626 			"	andi    %1, %2, 0x7\n"
1627 			"	beq     $0, %1, 9f\n"
1628 			"2:	lb      %1, 0(%2)\n"
1629 			"	dins   %0, %1, 8, 8\n"
1630 			"	daddiu  %2, %2, 1\n"
1631 			"	andi    %1, %2, 0x7\n"
1632 			"	beq     $0, %1, 9f\n"
1633 			"3:	lb      %1, 0(%2)\n"
1634 			"	dins   %0, %1, 16, 8\n"
1635 			"	daddiu  %2, %2, 1\n"
1636 			"	andi    %1, %2, 0x7\n"
1637 			"	beq     $0, %1, 9f\n"
1638 			"4:	lb      %1, 0(%2)\n"
1639 			"	dins   %0, %1, 24, 8\n"
1640 			"	daddiu  %2, %2, 1\n"
1641 			"	andi    %1, %2, 0x7\n"
1642 			"	beq     $0, %1, 9f\n"
1643 			"5:	lb      %1, 0(%2)\n"
1644 			"	dinsu    %0, %1, 32, 8\n"
1645 			"	daddiu  %2, %2, 1\n"
1646 			"	andi    %1, %2, 0x7\n"
1647 			"	beq     $0, %1, 9f\n"
1648 			"6:	lb      %1, 0(%2)\n"
1649 			"	dinsu    %0, %1, 40, 8\n"
1650 			"	daddiu  %2, %2, 1\n"
1651 			"	andi    %1, %2, 0x7\n"
1652 			"	beq     $0, %1, 9f\n"
1653 			"7:	lb      %1, 0(%2)\n"
1654 			"	dinsu    %0, %1, 48, 8\n"
1655 			"	daddiu  %2, %2, 1\n"
1656 			"	andi    %1, %2, 0x7\n"
1657 			"	beq     $0, %1, 9f\n"
1658 			"0:	lb      %1, 0(%2)\n"
1659 			"	dinsu    %0, %1, 56, 8\n"
1660 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1661 			"1:	lb      %1, 0(%2)\n"
1662 			"	dins   %0, %1, 0, 8\n"
1663 			"	andi    %1, %2, 0x7\n"
1664 			"	beq     $0, %1, 9f\n"
1665 			"	daddiu  %2, %2, -1\n"
1666 			"2:	lb      %1, 0(%2)\n"
1667 			"	dins   %0, %1, 8, 8\n"
1668 			"	andi    %1, %2, 0x7\n"
1669 			"	beq     $0, %1, 9f\n"
1670 			"	daddiu  %2, %2, -1\n"
1671 			"3:	lb      %1, 0(%2)\n"
1672 			"	dins   %0, %1, 16, 8\n"
1673 			"	andi    %1, %2, 0x7\n"
1674 			"	beq     $0, %1, 9f\n"
1675 			"	daddiu  %2, %2, -1\n"
1676 			"4:	lb      %1, 0(%2)\n"
1677 			"	dins   %0, %1, 24, 8\n"
1678 			"	andi    %1, %2, 0x7\n"
1679 			"	beq     $0, %1, 9f\n"
1680 			"	daddiu  %2, %2, -1\n"
1681 			"5:	lb      %1, 0(%2)\n"
1682 			"	dinsu    %0, %1, 32, 8\n"
1683 			"	andi    %1, %2, 0x7\n"
1684 			"	beq     $0, %1, 9f\n"
1685 			"	daddiu  %2, %2, -1\n"
1686 			"6:	lb      %1, 0(%2)\n"
1687 			"	dinsu    %0, %1, 40, 8\n"
1688 			"	andi    %1, %2, 0x7\n"
1689 			"	beq     $0, %1, 9f\n"
1690 			"	daddiu  %2, %2, -1\n"
1691 			"7:	lb      %1, 0(%2)\n"
1692 			"	dinsu    %0, %1, 48, 8\n"
1693 			"	andi    %1, %2, 0x7\n"
1694 			"	beq     $0, %1, 9f\n"
1695 			"	daddiu  %2, %2, -1\n"
1696 			"0:	lb      %1, 0(%2)\n"
1697 			"	dinsu    %0, %1, 56, 8\n"
1698 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1699 			"9:\n"
1700 			"	.insn\n"
1701 			"	.section        .fixup,\"ax\"\n"
1702 			"8:	li     %3,%4\n"
1703 			"	j      9b\n"
1704 			"	.previous\n"
1705 			"	.section        __ex_table,\"a\"\n"
1706 			STR(PTR) " 1b,8b\n"
1707 			STR(PTR) " 2b,8b\n"
1708 			STR(PTR) " 3b,8b\n"
1709 			STR(PTR) " 4b,8b\n"
1710 			STR(PTR) " 5b,8b\n"
1711 			STR(PTR) " 6b,8b\n"
1712 			STR(PTR) " 7b,8b\n"
1713 			STR(PTR) " 0b,8b\n"
1714 			"	.previous\n"
1715 			"	.set    pop\n"
1716 			: "+&r"(rt), "=&r"(rs),
1717 			  "+&r"(vaddr), "+&r"(err)
1718 			: "i"(SIGSEGV));
1719 		if (MIPSInst_RT(inst) && !err)
1720 			regs->regs[MIPSInst_RT(inst)] = rt;
1721 
1722 		MIPS_R2_STATS(loads);
1723 		break;
1724 
1725 	case sdl_op:
1726 		if (IS_ENABLED(CONFIG_32BIT)) {
1727 		    err = SIGILL;
1728 		    break;
1729 		}
1730 
1731 		rt = regs->regs[MIPSInst_RT(inst)];
1732 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1733 		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
1734 			current->thread.cp0_baduaddr = vaddr;
1735 			err = SIGSEGV;
1736 			break;
1737 		}
1738 		__asm__ __volatile__(
1739 			"	.set	push\n"
1740 			"	.set	reorder\n"
1741 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1742 			"	dextu	%1, %0, 56, 8\n"
1743 			"1:	sb	%1, 0(%2)\n"
1744 			"	andi	%1, %2, 0x7\n"
1745 			"	beq	$0, %1, 9f\n"
1746 			"	daddiu	%2, %2, -1\n"
1747 			"	dextu	%1, %0, 48, 8\n"
1748 			"2:	sb	%1, 0(%2)\n"
1749 			"	andi	%1, %2, 0x7\n"
1750 			"	beq	$0, %1, 9f\n"
1751 			"	daddiu	%2, %2, -1\n"
1752 			"	dextu	%1, %0, 40, 8\n"
1753 			"3:	sb	%1, 0(%2)\n"
1754 			"	andi	%1, %2, 0x7\n"
1755 			"	beq	$0, %1, 9f\n"
1756 			"	daddiu	%2, %2, -1\n"
1757 			"	dextu	%1, %0, 32, 8\n"
1758 			"4:	sb	%1, 0(%2)\n"
1759 			"	andi	%1, %2, 0x7\n"
1760 			"	beq	$0, %1, 9f\n"
1761 			"	daddiu	%2, %2, -1\n"
1762 			"	dext	%1, %0, 24, 8\n"
1763 			"5:	sb	%1, 0(%2)\n"
1764 			"	andi	%1, %2, 0x7\n"
1765 			"	beq	$0, %1, 9f\n"
1766 			"	daddiu	%2, %2, -1\n"
1767 			"	dext	%1, %0, 16, 8\n"
1768 			"6:	sb	%1, 0(%2)\n"
1769 			"	andi	%1, %2, 0x7\n"
1770 			"	beq	$0, %1, 9f\n"
1771 			"	daddiu	%2, %2, -1\n"
1772 			"	dext	%1, %0, 8, 8\n"
1773 			"7:	sb	%1, 0(%2)\n"
1774 			"	andi	%1, %2, 0x7\n"
1775 			"	beq	$0, %1, 9f\n"
1776 			"	daddiu	%2, %2, -1\n"
1777 			"	dext	%1, %0, 0, 8\n"
1778 			"0:	sb	%1, 0(%2)\n"
1779 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1780 			"	dextu	%1, %0, 56, 8\n"
1781 			"1:	sb	%1, 0(%2)\n"
1782 			"	daddiu	%2, %2, 1\n"
1783 			"	andi	%1, %2, 0x7\n"
1784 			"	beq	$0, %1, 9f\n"
1785 			"	dextu	%1, %0, 48, 8\n"
1786 			"2:	sb	%1, 0(%2)\n"
1787 			"	daddiu	%2, %2, 1\n"
1788 			"	andi	%1, %2, 0x7\n"
1789 			"	beq	$0, %1, 9f\n"
1790 			"	dextu	%1, %0, 40, 8\n"
1791 			"3:	sb	%1, 0(%2)\n"
1792 			"	daddiu	%2, %2, 1\n"
1793 			"	andi	%1, %2, 0x7\n"
1794 			"	beq	$0, %1, 9f\n"
1795 			"	dextu	%1, %0, 32, 8\n"
1796 			"4:	sb	%1, 0(%2)\n"
1797 			"	daddiu	%2, %2, 1\n"
1798 			"	andi	%1, %2, 0x7\n"
1799 			"	beq	$0, %1, 9f\n"
1800 			"	dext	%1, %0, 24, 8\n"
1801 			"5:	sb	%1, 0(%2)\n"
1802 			"	daddiu	%2, %2, 1\n"
1803 			"	andi	%1, %2, 0x7\n"
1804 			"	beq	$0, %1, 9f\n"
1805 			"	dext	%1, %0, 16, 8\n"
1806 			"6:	sb	%1, 0(%2)\n"
1807 			"	daddiu	%2, %2, 1\n"
1808 			"	andi	%1, %2, 0x7\n"
1809 			"	beq	$0, %1, 9f\n"
1810 			"	dext	%1, %0, 8, 8\n"
1811 			"7:	sb	%1, 0(%2)\n"
1812 			"	daddiu	%2, %2, 1\n"
1813 			"	andi	%1, %2, 0x7\n"
1814 			"	beq	$0, %1, 9f\n"
1815 			"	dext	%1, %0, 0, 8\n"
1816 			"0:	sb	%1, 0(%2)\n"
1817 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1818 			"9:\n"
1819 			"	.insn\n"
1820 			"	.section        .fixup,\"ax\"\n"
1821 			"8:	li	%3,%4\n"
1822 			"	j	9b\n"
1823 			"	.previous\n"
1824 			"	.section        __ex_table,\"a\"\n"
1825 			STR(PTR) " 1b,8b\n"
1826 			STR(PTR) " 2b,8b\n"
1827 			STR(PTR) " 3b,8b\n"
1828 			STR(PTR) " 4b,8b\n"
1829 			STR(PTR) " 5b,8b\n"
1830 			STR(PTR) " 6b,8b\n"
1831 			STR(PTR) " 7b,8b\n"
1832 			STR(PTR) " 0b,8b\n"
1833 			"	.previous\n"
1834 			"	.set	pop\n"
1835 			: "+&r"(rt), "=&r"(rs),
1836 			  "+&r"(vaddr), "+&r"(err)
1837 			: "i"(SIGSEGV)
1838 			: "memory");
1839 
1840 		MIPS_R2_STATS(stores);
1841 		break;
1842 
1843 	case sdr_op:
1844 		if (IS_ENABLED(CONFIG_32BIT)) {
1845 		    err = SIGILL;
1846 		    break;
1847 		}
1848 
1849 		rt = regs->regs[MIPSInst_RT(inst)];
1850 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1851 		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
1852 			current->thread.cp0_baduaddr = vaddr;
1853 			err = SIGSEGV;
1854 			break;
1855 		}
1856 		__asm__ __volatile__(
1857 			"       .set	push\n"
1858 			"       .set	reorder\n"
1859 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1860 			"       dext	%1, %0, 0, 8\n"
1861 			"1:     sb	%1, 0(%2)\n"
1862 			"       daddiu	%2, %2, 1\n"
1863 			"       andi	%1, %2, 0x7\n"
1864 			"       beq	$0, %1, 9f\n"
1865 			"       dext	%1, %0, 8, 8\n"
1866 			"2:     sb	%1, 0(%2)\n"
1867 			"       daddiu	%2, %2, 1\n"
1868 			"       andi	%1, %2, 0x7\n"
1869 			"       beq	$0, %1, 9f\n"
1870 			"       dext	%1, %0, 16, 8\n"
1871 			"3:     sb	%1, 0(%2)\n"
1872 			"       daddiu	%2, %2, 1\n"
1873 			"       andi	%1, %2, 0x7\n"
1874 			"       beq	$0, %1, 9f\n"
1875 			"       dext	%1, %0, 24, 8\n"
1876 			"4:     sb	%1, 0(%2)\n"
1877 			"       daddiu	%2, %2, 1\n"
1878 			"       andi	%1, %2, 0x7\n"
1879 			"       beq	$0, %1, 9f\n"
1880 			"       dextu	%1, %0, 32, 8\n"
1881 			"5:     sb	%1, 0(%2)\n"
1882 			"       daddiu	%2, %2, 1\n"
1883 			"       andi	%1, %2, 0x7\n"
1884 			"       beq	$0, %1, 9f\n"
1885 			"       dextu	%1, %0, 40, 8\n"
1886 			"6:     sb	%1, 0(%2)\n"
1887 			"       daddiu	%2, %2, 1\n"
1888 			"       andi	%1, %2, 0x7\n"
1889 			"       beq	$0, %1, 9f\n"
1890 			"       dextu	%1, %0, 48, 8\n"
1891 			"7:     sb	%1, 0(%2)\n"
1892 			"       daddiu	%2, %2, 1\n"
1893 			"       andi	%1, %2, 0x7\n"
1894 			"       beq	$0, %1, 9f\n"
1895 			"       dextu	%1, %0, 56, 8\n"
1896 			"0:     sb	%1, 0(%2)\n"
1897 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1898 			"       dext	%1, %0, 0, 8\n"
1899 			"1:     sb	%1, 0(%2)\n"
1900 			"       andi	%1, %2, 0x7\n"
1901 			"       beq	$0, %1, 9f\n"
1902 			"       daddiu	%2, %2, -1\n"
1903 			"       dext	%1, %0, 8, 8\n"
1904 			"2:     sb	%1, 0(%2)\n"
1905 			"       andi	%1, %2, 0x7\n"
1906 			"       beq	$0, %1, 9f\n"
1907 			"       daddiu	%2, %2, -1\n"
1908 			"       dext	%1, %0, 16, 8\n"
1909 			"3:     sb	%1, 0(%2)\n"
1910 			"       andi	%1, %2, 0x7\n"
1911 			"       beq	$0, %1, 9f\n"
1912 			"       daddiu	%2, %2, -1\n"
1913 			"       dext	%1, %0, 24, 8\n"
1914 			"4:     sb	%1, 0(%2)\n"
1915 			"       andi	%1, %2, 0x7\n"
1916 			"       beq	$0, %1, 9f\n"
1917 			"       daddiu	%2, %2, -1\n"
1918 			"       dextu	%1, %0, 32, 8\n"
1919 			"5:     sb	%1, 0(%2)\n"
1920 			"       andi	%1, %2, 0x7\n"
1921 			"       beq	$0, %1, 9f\n"
1922 			"       daddiu	%2, %2, -1\n"
1923 			"       dextu	%1, %0, 40, 8\n"
1924 			"6:     sb	%1, 0(%2)\n"
1925 			"       andi	%1, %2, 0x7\n"
1926 			"       beq	$0, %1, 9f\n"
1927 			"       daddiu	%2, %2, -1\n"
1928 			"       dextu	%1, %0, 48, 8\n"
1929 			"7:     sb	%1, 0(%2)\n"
1930 			"       andi	%1, %2, 0x7\n"
1931 			"       beq	$0, %1, 9f\n"
1932 			"       daddiu	%2, %2, -1\n"
1933 			"       dextu	%1, %0, 56, 8\n"
1934 			"0:     sb	%1, 0(%2)\n"
1935 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1936 			"9:\n"
1937 			"       .insn\n"
1938 			"       .section        .fixup,\"ax\"\n"
1939 			"8:     li	%3,%4\n"
1940 			"       j	9b\n"
1941 			"       .previous\n"
1942 			"       .section        __ex_table,\"a\"\n"
1943 			STR(PTR) " 1b,8b\n"
1944 			STR(PTR) " 2b,8b\n"
1945 			STR(PTR) " 3b,8b\n"
1946 			STR(PTR) " 4b,8b\n"
1947 			STR(PTR) " 5b,8b\n"
1948 			STR(PTR) " 6b,8b\n"
1949 			STR(PTR) " 7b,8b\n"
1950 			STR(PTR) " 0b,8b\n"
1951 			"       .previous\n"
1952 			"       .set	pop\n"
1953 			: "+&r"(rt), "=&r"(rs),
1954 			  "+&r"(vaddr), "+&r"(err)
1955 			: "i"(SIGSEGV)
1956 			: "memory");
1957 
1958 		MIPS_R2_STATS(stores);
1959 
1960 		break;
1961 	case ll_op:
1962 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1963 		if (vaddr & 0x3) {
1964 			current->thread.cp0_baduaddr = vaddr;
1965 			err = SIGBUS;
1966 			break;
1967 		}
1968 		if (!access_ok(VERIFY_READ, vaddr, 4)) {
1969 			current->thread.cp0_baduaddr = vaddr;
1970 			err = SIGBUS;
1971 			break;
1972 		}
1973 
1974 		if (!cpu_has_rw_llb) {
1975 			/*
1976 			 * An LL/SC block can't be safely emulated without
1977 			 * a Config5/LLB availability. So it's probably time to
1978 			 * kill our process before things get any worse. This is
1979 			 * because Config5/LLB allows us to use ERETNC so that
1980 			 * the LLAddr/LLB bit is not cleared when we return from
1981 			 * an exception. MIPS R2 LL/SC instructions trap with an
1982 			 * RI exception so once we emulate them here, we return
1983 			 * back to userland with ERETNC. That preserves the
1984 			 * LLAddr/LLB so the subsequent SC instruction will
1985 			 * succeed preserving the atomic semantics of the LL/SC
1986 			 * block. Without that, there is no safe way to emulate
1987 			 * an LL/SC block in MIPSR2 userland.
1988 			 */
1989 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
1990 			err = SIGKILL;
1991 			break;
1992 		}
1993 
1994 		__asm__ __volatile__(
1995 			"1:\n"
1996 			"ll	%0, 0(%2)\n"
1997 			"2:\n"
1998 			".insn\n"
1999 			".section        .fixup,\"ax\"\n"
2000 			"3:\n"
2001 			"li	%1, %3\n"
2002 			"j	2b\n"
2003 			".previous\n"
2004 			".section        __ex_table,\"a\"\n"
2005 			STR(PTR) " 1b,3b\n"
2006 			".previous\n"
2007 			: "=&r"(res), "+&r"(err)
2008 			: "r"(vaddr), "i"(SIGSEGV)
2009 			: "memory");
2010 
2011 		if (MIPSInst_RT(inst) && !err)
2012 			regs->regs[MIPSInst_RT(inst)] = res;
2013 		MIPS_R2_STATS(llsc);
2014 
2015 		break;
2016 
2017 	case sc_op:
2018 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
2019 		if (vaddr & 0x3) {
2020 			current->thread.cp0_baduaddr = vaddr;
2021 			err = SIGBUS;
2022 			break;
2023 		}
2024 		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
2025 			current->thread.cp0_baduaddr = vaddr;
2026 			err = SIGBUS;
2027 			break;
2028 		}
2029 
2030 		if (!cpu_has_rw_llb) {
2031 			/*
2032 			 * An LL/SC block can't be safely emulated without
2033 			 * a Config5/LLB availability. So it's probably time to
2034 			 * kill our process before things get any worse. This is
2035 			 * because Config5/LLB allows us to use ERETNC so that
2036 			 * the LLAddr/LLB bit is not cleared when we return from
2037 			 * an exception. MIPS R2 LL/SC instructions trap with an
2038 			 * RI exception so once we emulate them here, we return
2039 			 * back to userland with ERETNC. That preserves the
2040 			 * LLAddr/LLB so the subsequent SC instruction will
2041 			 * succeed preserving the atomic semantics of the LL/SC
2042 			 * block. Without that, there is no safe way to emulate
2043 			 * an LL/SC block in MIPSR2 userland.
2044 			 */
2045 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
2046 			err = SIGKILL;
2047 			break;
2048 		}
2049 
2050 		res = regs->regs[MIPSInst_RT(inst)];
2051 
2052 		__asm__ __volatile__(
2053 			"1:\n"
2054 			"sc	%0, 0(%2)\n"
2055 			"2:\n"
2056 			".insn\n"
2057 			".section        .fixup,\"ax\"\n"
2058 			"3:\n"
2059 			"li	%1, %3\n"
2060 			"j	2b\n"
2061 			".previous\n"
2062 			".section        __ex_table,\"a\"\n"
2063 			STR(PTR) " 1b,3b\n"
2064 			".previous\n"
2065 			: "+&r"(res), "+&r"(err)
2066 			: "r"(vaddr), "i"(SIGSEGV));
2067 
2068 		if (MIPSInst_RT(inst) && !err)
2069 			regs->regs[MIPSInst_RT(inst)] = res;
2070 
2071 		MIPS_R2_STATS(llsc);
2072 
2073 		break;
2074 
2075 	case lld_op:
2076 		if (IS_ENABLED(CONFIG_32BIT)) {
2077 		    err = SIGILL;
2078 		    break;
2079 		}
2080 
2081 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
2082 		if (vaddr & 0x7) {
2083 			current->thread.cp0_baduaddr = vaddr;
2084 			err = SIGBUS;
2085 			break;
2086 		}
2087 		if (!access_ok(VERIFY_READ, vaddr, 8)) {
2088 			current->thread.cp0_baduaddr = vaddr;
2089 			err = SIGBUS;
2090 			break;
2091 		}
2092 
2093 		if (!cpu_has_rw_llb) {
2094 			/*
2095 			 * An LL/SC block can't be safely emulated without
2096 			 * a Config5/LLB availability. So it's probably time to
2097 			 * kill our process before things get any worse. This is
2098 			 * because Config5/LLB allows us to use ERETNC so that
2099 			 * the LLAddr/LLB bit is not cleared when we return from
2100 			 * an exception. MIPS R2 LL/SC instructions trap with an
2101 			 * RI exception so once we emulate them here, we return
2102 			 * back to userland with ERETNC. That preserves the
2103 			 * LLAddr/LLB so the subsequent SC instruction will
2104 			 * succeed preserving the atomic semantics of the LL/SC
2105 			 * block. Without that, there is no safe way to emulate
2106 			 * an LL/SC block in MIPSR2 userland.
2107 			 */
2108 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
2109 			err = SIGKILL;
2110 			break;
2111 		}
2112 
2113 		__asm__ __volatile__(
2114 			"1:\n"
2115 			"lld	%0, 0(%2)\n"
2116 			"2:\n"
2117 			".insn\n"
2118 			".section        .fixup,\"ax\"\n"
2119 			"3:\n"
2120 			"li	%1, %3\n"
2121 			"j	2b\n"
2122 			".previous\n"
2123 			".section        __ex_table,\"a\"\n"
2124 			STR(PTR) " 1b,3b\n"
2125 			".previous\n"
2126 			: "=&r"(res), "+&r"(err)
2127 			: "r"(vaddr), "i"(SIGSEGV)
2128 			: "memory");
2129 		if (MIPSInst_RT(inst) && !err)
2130 			regs->regs[MIPSInst_RT(inst)] = res;
2131 
2132 		MIPS_R2_STATS(llsc);
2133 
2134 		break;
2135 
2136 	case scd_op:
2137 		if (IS_ENABLED(CONFIG_32BIT)) {
2138 		    err = SIGILL;
2139 		    break;
2140 		}
2141 
2142 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
2143 		if (vaddr & 0x7) {
2144 			current->thread.cp0_baduaddr = vaddr;
2145 			err = SIGBUS;
2146 			break;
2147 		}
2148 		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
2149 			current->thread.cp0_baduaddr = vaddr;
2150 			err = SIGBUS;
2151 			break;
2152 		}
2153 
2154 		if (!cpu_has_rw_llb) {
2155 			/*
2156 			 * An LL/SC block can't be safely emulated without
2157 			 * a Config5/LLB availability. So it's probably time to
2158 			 * kill our process before things get any worse. This is
2159 			 * because Config5/LLB allows us to use ERETNC so that
2160 			 * the LLAddr/LLB bit is not cleared when we return from
2161 			 * an exception. MIPS R2 LL/SC instructions trap with an
2162 			 * RI exception so once we emulate them here, we return
2163 			 * back to userland with ERETNC. That preserves the
2164 			 * LLAddr/LLB so the subsequent SC instruction will
2165 			 * succeed preserving the atomic semantics of the LL/SC
2166 			 * block. Without that, there is no safe way to emulate
2167 			 * an LL/SC block in MIPSR2 userland.
2168 			 */
2169 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
2170 			err = SIGKILL;
2171 			break;
2172 		}
2173 
2174 		res = regs->regs[MIPSInst_RT(inst)];
2175 
2176 		__asm__ __volatile__(
2177 			"1:\n"
2178 			"scd	%0, 0(%2)\n"
2179 			"2:\n"
2180 			".insn\n"
2181 			".section        .fixup,\"ax\"\n"
2182 			"3:\n"
2183 			"li	%1, %3\n"
2184 			"j	2b\n"
2185 			".previous\n"
2186 			".section        __ex_table,\"a\"\n"
2187 			STR(PTR) " 1b,3b\n"
2188 			".previous\n"
2189 			: "+&r"(res), "+&r"(err)
2190 			: "r"(vaddr), "i"(SIGSEGV));
2191 
2192 		if (MIPSInst_RT(inst) && !err)
2193 			regs->regs[MIPSInst_RT(inst)] = res;
2194 
2195 		MIPS_R2_STATS(llsc);
2196 
2197 		break;
2198 	case pref_op:
2199 		/* skip it */
2200 		break;
2201 	default:
2202 		err = SIGILL;
2203 	}
2204 
2205 	/*
2206 	 * Let's not return to userland just yet. It's costly and
2207 	 * it's likely we have more R2 instructions to emulate
2208 	 */
2209 	if (!err && (pass++ < MIPS_R2_EMUL_TOTAL_PASS)) {
2210 		regs->cp0_cause &= ~CAUSEF_BD;
2211 		err = get_user(inst, (u32 __user *)regs->cp0_epc);
2212 		if (!err)
2213 			goto repeat;
2214 
2215 		if (err < 0)
2216 			err = SIGSEGV;
2217 	}
2218 
2219 	if (err && (err != SIGEMT)) {
2220 		regs->regs[31] = r31;
2221 		regs->cp0_epc = epc;
2222 	}
2223 
2224 	/* Likely a MIPS R6 compatible instruction */
2225 	if (pass && (err == SIGILL))
2226 		err = 0;
2227 
2228 	return err;
2229 }
2230 
2231 #ifdef CONFIG_DEBUG_FS
2232 
2233 static int mipsr2_stats_show(struct seq_file *s, void *unused)
2234 {
2235 
2236 	seq_printf(s, "Instruction\tTotal\tBDslot\n------------------------------\n");
2237 	seq_printf(s, "movs\t\t%ld\t%ld\n",
2238 		   (unsigned long)__this_cpu_read(mipsr2emustats.movs),
2239 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.movs));
2240 	seq_printf(s, "hilo\t\t%ld\t%ld\n",
2241 		   (unsigned long)__this_cpu_read(mipsr2emustats.hilo),
2242 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.hilo));
2243 	seq_printf(s, "muls\t\t%ld\t%ld\n",
2244 		   (unsigned long)__this_cpu_read(mipsr2emustats.muls),
2245 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.muls));
2246 	seq_printf(s, "divs\t\t%ld\t%ld\n",
2247 		   (unsigned long)__this_cpu_read(mipsr2emustats.divs),
2248 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.divs));
2249 	seq_printf(s, "dsps\t\t%ld\t%ld\n",
2250 		   (unsigned long)__this_cpu_read(mipsr2emustats.dsps),
2251 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.dsps));
2252 	seq_printf(s, "bops\t\t%ld\t%ld\n",
2253 		   (unsigned long)__this_cpu_read(mipsr2emustats.bops),
2254 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.bops));
2255 	seq_printf(s, "traps\t\t%ld\t%ld\n",
2256 		   (unsigned long)__this_cpu_read(mipsr2emustats.traps),
2257 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.traps));
2258 	seq_printf(s, "fpus\t\t%ld\t%ld\n",
2259 		   (unsigned long)__this_cpu_read(mipsr2emustats.fpus),
2260 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.fpus));
2261 	seq_printf(s, "loads\t\t%ld\t%ld\n",
2262 		   (unsigned long)__this_cpu_read(mipsr2emustats.loads),
2263 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.loads));
2264 	seq_printf(s, "stores\t\t%ld\t%ld\n",
2265 		   (unsigned long)__this_cpu_read(mipsr2emustats.stores),
2266 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.stores));
2267 	seq_printf(s, "llsc\t\t%ld\t%ld\n",
2268 		   (unsigned long)__this_cpu_read(mipsr2emustats.llsc),
2269 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.llsc));
2270 	seq_printf(s, "dsemul\t\t%ld\t%ld\n",
2271 		   (unsigned long)__this_cpu_read(mipsr2emustats.dsemul),
2272 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.dsemul));
2273 	seq_printf(s, "jr\t\t%ld\n",
2274 		   (unsigned long)__this_cpu_read(mipsr2bremustats.jrs));
2275 	seq_printf(s, "bltzl\t\t%ld\n",
2276 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bltzl));
2277 	seq_printf(s, "bgezl\t\t%ld\n",
2278 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgezl));
2279 	seq_printf(s, "bltzll\t\t%ld\n",
2280 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bltzll));
2281 	seq_printf(s, "bgezll\t\t%ld\n",
2282 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgezll));
2283 	seq_printf(s, "bltzal\t\t%ld\n",
2284 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bltzal));
2285 	seq_printf(s, "bgezal\t\t%ld\n",
2286 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgezal));
2287 	seq_printf(s, "beql\t\t%ld\n",
2288 		   (unsigned long)__this_cpu_read(mipsr2bremustats.beql));
2289 	seq_printf(s, "bnel\t\t%ld\n",
2290 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bnel));
2291 	seq_printf(s, "blezl\t\t%ld\n",
2292 		   (unsigned long)__this_cpu_read(mipsr2bremustats.blezl));
2293 	seq_printf(s, "bgtzl\t\t%ld\n",
2294 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgtzl));
2295 
2296 	return 0;
2297 }
2298 
2299 static int mipsr2_stats_clear_show(struct seq_file *s, void *unused)
2300 {
2301 	mipsr2_stats_show(s, unused);
2302 
2303 	__this_cpu_write((mipsr2emustats).movs, 0);
2304 	__this_cpu_write((mipsr2bdemustats).movs, 0);
2305 	__this_cpu_write((mipsr2emustats).hilo, 0);
2306 	__this_cpu_write((mipsr2bdemustats).hilo, 0);
2307 	__this_cpu_write((mipsr2emustats).muls, 0);
2308 	__this_cpu_write((mipsr2bdemustats).muls, 0);
2309 	__this_cpu_write((mipsr2emustats).divs, 0);
2310 	__this_cpu_write((mipsr2bdemustats).divs, 0);
2311 	__this_cpu_write((mipsr2emustats).dsps, 0);
2312 	__this_cpu_write((mipsr2bdemustats).dsps, 0);
2313 	__this_cpu_write((mipsr2emustats).bops, 0);
2314 	__this_cpu_write((mipsr2bdemustats).bops, 0);
2315 	__this_cpu_write((mipsr2emustats).traps, 0);
2316 	__this_cpu_write((mipsr2bdemustats).traps, 0);
2317 	__this_cpu_write((mipsr2emustats).fpus, 0);
2318 	__this_cpu_write((mipsr2bdemustats).fpus, 0);
2319 	__this_cpu_write((mipsr2emustats).loads, 0);
2320 	__this_cpu_write((mipsr2bdemustats).loads, 0);
2321 	__this_cpu_write((mipsr2emustats).stores, 0);
2322 	__this_cpu_write((mipsr2bdemustats).stores, 0);
2323 	__this_cpu_write((mipsr2emustats).llsc, 0);
2324 	__this_cpu_write((mipsr2bdemustats).llsc, 0);
2325 	__this_cpu_write((mipsr2emustats).dsemul, 0);
2326 	__this_cpu_write((mipsr2bdemustats).dsemul, 0);
2327 	__this_cpu_write((mipsr2bremustats).jrs, 0);
2328 	__this_cpu_write((mipsr2bremustats).bltzl, 0);
2329 	__this_cpu_write((mipsr2bremustats).bgezl, 0);
2330 	__this_cpu_write((mipsr2bremustats).bltzll, 0);
2331 	__this_cpu_write((mipsr2bremustats).bgezll, 0);
2332 	__this_cpu_write((mipsr2bremustats).bltzal, 0);
2333 	__this_cpu_write((mipsr2bremustats).bgezal, 0);
2334 	__this_cpu_write((mipsr2bremustats).beql, 0);
2335 	__this_cpu_write((mipsr2bremustats).bnel, 0);
2336 	__this_cpu_write((mipsr2bremustats).blezl, 0);
2337 	__this_cpu_write((mipsr2bremustats).bgtzl, 0);
2338 
2339 	return 0;
2340 }
2341 
2342 static int mipsr2_stats_open(struct inode *inode, struct file *file)
2343 {
2344 	return single_open(file, mipsr2_stats_show, inode->i_private);
2345 }
2346 
2347 static int mipsr2_stats_clear_open(struct inode *inode, struct file *file)
2348 {
2349 	return single_open(file, mipsr2_stats_clear_show, inode->i_private);
2350 }
2351 
2352 static const struct file_operations mipsr2_emul_fops = {
2353 	.open                   = mipsr2_stats_open,
2354 	.read			= seq_read,
2355 	.llseek			= seq_lseek,
2356 	.release		= single_release,
2357 };
2358 
2359 static const struct file_operations mipsr2_clear_fops = {
2360 	.open                   = mipsr2_stats_clear_open,
2361 	.read			= seq_read,
2362 	.llseek			= seq_lseek,
2363 	.release		= single_release,
2364 };
2365 
2366 
2367 static int __init mipsr2_init_debugfs(void)
2368 {
2369 	struct dentry		*mipsr2_emul;
2370 
2371 	if (!mips_debugfs_dir)
2372 		return -ENODEV;
2373 
2374 	mipsr2_emul = debugfs_create_file("r2_emul_stats", S_IRUGO,
2375 					  mips_debugfs_dir, NULL,
2376 					  &mipsr2_emul_fops);
2377 	if (!mipsr2_emul)
2378 		return -ENOMEM;
2379 
2380 	mipsr2_emul = debugfs_create_file("r2_emul_stats_clear", S_IRUGO,
2381 					  mips_debugfs_dir, NULL,
2382 					  &mipsr2_clear_fops);
2383 	if (!mipsr2_emul)
2384 		return -ENOMEM;
2385 
2386 	return 0;
2387 }
2388 
2389 device_initcall(mipsr2_init_debugfs);
2390 
2391 #endif /* CONFIG_DEBUG_FS */
2392