xref: /linux/arch/mips/kernel/mips-r2-to-r6-emul.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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/module.h>
19 #include <linux/ptrace.h>
20 #include <linux/seq_file.h>
21 
22 #include <asm/asm.h>
23 #include <asm/branch.h>
24 #include <asm/break.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/ptrace.h>
31 #include <asm/uaccess.h>
32 
33 #ifdef CONFIG_64BIT
34 #define ADDIU	"daddiu "
35 #define INS	"dins "
36 #define EXT	"dext "
37 #else
38 #define ADDIU	"addiu "
39 #define INS	"ins "
40 #define EXT	"ext "
41 #endif /* CONFIG_64BIT */
42 
43 #define SB	"sb "
44 #define LB	"lb "
45 #define LL	"ll "
46 #define SC	"sc "
47 
48 DEFINE_PER_CPU(struct mips_r2_emulator_stats, mipsr2emustats);
49 DEFINE_PER_CPU(struct mips_r2_emulator_stats, mipsr2bdemustats);
50 DEFINE_PER_CPU(struct mips_r2br_emulator_stats, mipsr2bremustats);
51 
52 extern const unsigned int fpucondbit[8];
53 
54 #define MIPS_R2_EMUL_TOTAL_PASS	10
55 
56 int mipsr2_emulation = 0;
57 
58 static int __init mipsr2emu_enable(char *s)
59 {
60 	mipsr2_emulation = 1;
61 
62 	pr_info("MIPS R2-to-R6 Emulator Enabled!");
63 
64 	return 1;
65 }
66 __setup("mipsr2emu", mipsr2emu_enable);
67 
68 /**
69  * mipsr6_emul - Emulate some frequent R2/R5/R6 instructions in delay slot
70  * for performance instead of the traditional way of using a stack trampoline
71  * which is rather slow.
72  * @regs: Process register set
73  * @ir: Instruction
74  */
75 static inline int mipsr6_emul(struct pt_regs *regs, u32 ir)
76 {
77 	switch (MIPSInst_OPCODE(ir)) {
78 	case addiu_op:
79 		if (MIPSInst_RT(ir))
80 			regs->regs[MIPSInst_RT(ir)] =
81 				(s32)regs->regs[MIPSInst_RS(ir)] +
82 				(s32)MIPSInst_SIMM(ir);
83 		return 0;
84 	case daddiu_op:
85 		if (config_enabled(CONFIG_32BIT))
86 			break;
87 
88 		if (MIPSInst_RT(ir))
89 			regs->regs[MIPSInst_RT(ir)] =
90 				(s64)regs->regs[MIPSInst_RS(ir)] +
91 				(s64)MIPSInst_SIMM(ir);
92 		return 0;
93 	case lwc1_op:
94 	case swc1_op:
95 	case cop1_op:
96 	case cop1x_op:
97 		/* FPU instructions in delay slot */
98 		return -SIGFPE;
99 	case spec_op:
100 		switch (MIPSInst_FUNC(ir)) {
101 		case or_op:
102 			if (MIPSInst_RD(ir))
103 				regs->regs[MIPSInst_RD(ir)] =
104 					regs->regs[MIPSInst_RS(ir)] |
105 					regs->regs[MIPSInst_RT(ir)];
106 			return 0;
107 		case sll_op:
108 			if (MIPSInst_RS(ir))
109 				break;
110 
111 			if (MIPSInst_RD(ir))
112 				regs->regs[MIPSInst_RD(ir)] =
113 					(s32)(((u32)regs->regs[MIPSInst_RT(ir)]) <<
114 						MIPSInst_FD(ir));
115 			return 0;
116 		case srl_op:
117 			if (MIPSInst_RS(ir))
118 				break;
119 
120 			if (MIPSInst_RD(ir))
121 				regs->regs[MIPSInst_RD(ir)] =
122 					(s32)(((u32)regs->regs[MIPSInst_RT(ir)]) >>
123 						MIPSInst_FD(ir));
124 			return 0;
125 		case addu_op:
126 			if (MIPSInst_FD(ir))
127 				break;
128 
129 			if (MIPSInst_RD(ir))
130 				regs->regs[MIPSInst_RD(ir)] =
131 					(s32)((u32)regs->regs[MIPSInst_RS(ir)] +
132 					      (u32)regs->regs[MIPSInst_RT(ir)]);
133 			return 0;
134 		case subu_op:
135 			if (MIPSInst_FD(ir))
136 				break;
137 
138 			if (MIPSInst_RD(ir))
139 				regs->regs[MIPSInst_RD(ir)] =
140 					(s32)((u32)regs->regs[MIPSInst_RS(ir)] -
141 					      (u32)regs->regs[MIPSInst_RT(ir)]);
142 			return 0;
143 		case dsll_op:
144 			if (config_enabled(CONFIG_32BIT) || MIPSInst_RS(ir))
145 				break;
146 
147 			if (MIPSInst_RD(ir))
148 				regs->regs[MIPSInst_RD(ir)] =
149 					(s64)(((u64)regs->regs[MIPSInst_RT(ir)]) <<
150 						MIPSInst_FD(ir));
151 			return 0;
152 		case dsrl_op:
153 			if (config_enabled(CONFIG_32BIT) || MIPSInst_RS(ir))
154 				break;
155 
156 			if (MIPSInst_RD(ir))
157 				regs->regs[MIPSInst_RD(ir)] =
158 					(s64)(((u64)regs->regs[MIPSInst_RT(ir)]) >>
159 						MIPSInst_FD(ir));
160 			return 0;
161 		case daddu_op:
162 			if (config_enabled(CONFIG_32BIT) || MIPSInst_FD(ir))
163 				break;
164 
165 			if (MIPSInst_RD(ir))
166 				regs->regs[MIPSInst_RD(ir)] =
167 					(u64)regs->regs[MIPSInst_RS(ir)] +
168 					(u64)regs->regs[MIPSInst_RT(ir)];
169 			return 0;
170 		case dsubu_op:
171 			if (config_enabled(CONFIG_32BIT) || MIPSInst_FD(ir))
172 				break;
173 
174 			if (MIPSInst_RD(ir))
175 				regs->regs[MIPSInst_RD(ir)] =
176 					(s64)((u64)regs->regs[MIPSInst_RS(ir)] -
177 					      (u64)regs->regs[MIPSInst_RT(ir)]);
178 			return 0;
179 		}
180 		break;
181 	default:
182 		pr_debug("No fastpath BD emulation for instruction 0x%08x (op: %02x)\n",
183 			 ir, MIPSInst_OPCODE(ir));
184 	}
185 
186 	return SIGILL;
187 }
188 
189 /**
190  * movf_func - Emulate a MOVF instruction
191  * @regs: Process register set
192  * @ir: Instruction
193  *
194  * Returns 0 since it always succeeds.
195  */
196 static int movf_func(struct pt_regs *regs, u32 ir)
197 {
198 	u32 csr;
199 	u32 cond;
200 
201 	csr = current->thread.fpu.fcr31;
202 	cond = fpucondbit[MIPSInst_RT(ir) >> 2];
203 
204 	if (((csr & cond) == 0) && MIPSInst_RD(ir))
205 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
206 
207 	MIPS_R2_STATS(movs);
208 
209 	return 0;
210 }
211 
212 /**
213  * movt_func - Emulate a MOVT instruction
214  * @regs: Process register set
215  * @ir: Instruction
216  *
217  * Returns 0 since it always succeeds.
218  */
219 static int movt_func(struct pt_regs *regs, u32 ir)
220 {
221 	u32 csr;
222 	u32 cond;
223 
224 	csr = current->thread.fpu.fcr31;
225 	cond = fpucondbit[MIPSInst_RT(ir) >> 2];
226 
227 	if (((csr & cond) != 0) && MIPSInst_RD(ir))
228 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
229 
230 	MIPS_R2_STATS(movs);
231 
232 	return 0;
233 }
234 
235 /**
236  * jr_func - Emulate a JR instruction.
237  * @pt_regs: Process register set
238  * @ir: Instruction
239  *
240  * Returns SIGILL if JR was in delay slot, SIGEMT if we
241  * can't compute the EPC, SIGSEGV if we can't access the
242  * userland instruction or 0 on success.
243  */
244 static int jr_func(struct pt_regs *regs, u32 ir)
245 {
246 	int err;
247 	unsigned long cepc, epc, nepc;
248 	u32 nir;
249 
250 	if (delay_slot(regs))
251 		return SIGILL;
252 
253 	/* EPC after the RI/JR instruction */
254 	nepc = regs->cp0_epc;
255 	/* Roll back to the reserved R2 JR instruction */
256 	regs->cp0_epc -= 4;
257 	epc = regs->cp0_epc;
258 	err = __compute_return_epc(regs);
259 
260 	if (err < 0)
261 		return SIGEMT;
262 
263 
264 	/* Computed EPC */
265 	cepc = regs->cp0_epc;
266 
267 	/* Get DS instruction */
268 	err = __get_user(nir, (u32 __user *)nepc);
269 	if (err)
270 		return SIGSEGV;
271 
272 	MIPS_R2BR_STATS(jrs);
273 
274 	/* If nir == 0(NOP), then nothing else to do */
275 	if (nir) {
276 		/*
277 		 * Negative err means FPU instruction in BD-slot,
278 		 * Zero err means 'BD-slot emulation done'
279 		 * For anything else we go back to trampoline emulation.
280 		 */
281 		err = mipsr6_emul(regs, nir);
282 		if (err > 0) {
283 			regs->cp0_epc = nepc;
284 			err = mips_dsemul(regs, nir, cepc);
285 			if (err == SIGILL)
286 				err = SIGEMT;
287 			MIPS_R2_STATS(dsemul);
288 		}
289 	}
290 
291 	return err;
292 }
293 
294 /**
295  * movz_func - Emulate a MOVZ instruction
296  * @regs: Process register set
297  * @ir: Instruction
298  *
299  * Returns 0 since it always succeeds.
300  */
301 static int movz_func(struct pt_regs *regs, u32 ir)
302 {
303 	if (((regs->regs[MIPSInst_RT(ir)]) == 0) && MIPSInst_RD(ir))
304 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
305 	MIPS_R2_STATS(movs);
306 
307 	return 0;
308 }
309 
310 /**
311  * movn_func - Emulate a MOVZ instruction
312  * @regs: Process register set
313  * @ir: Instruction
314  *
315  * Returns 0 since it always succeeds.
316  */
317 static int movn_func(struct pt_regs *regs, u32 ir)
318 {
319 	if (((regs->regs[MIPSInst_RT(ir)]) != 0) && MIPSInst_RD(ir))
320 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
321 	MIPS_R2_STATS(movs);
322 
323 	return 0;
324 }
325 
326 /**
327  * mfhi_func - Emulate a MFHI instruction
328  * @regs: Process register set
329  * @ir: Instruction
330  *
331  * Returns 0 since it always succeeds.
332  */
333 static int mfhi_func(struct pt_regs *regs, u32 ir)
334 {
335 	if (MIPSInst_RD(ir))
336 		regs->regs[MIPSInst_RD(ir)] = regs->hi;
337 
338 	MIPS_R2_STATS(hilo);
339 
340 	return 0;
341 }
342 
343 /**
344  * mthi_func - Emulate a MTHI instruction
345  * @regs: Process register set
346  * @ir: Instruction
347  *
348  * Returns 0 since it always succeeds.
349  */
350 static int mthi_func(struct pt_regs *regs, u32 ir)
351 {
352 	regs->hi = regs->regs[MIPSInst_RS(ir)];
353 
354 	MIPS_R2_STATS(hilo);
355 
356 	return 0;
357 }
358 
359 /**
360  * mflo_func - Emulate a MFLO instruction
361  * @regs: Process register set
362  * @ir: Instruction
363  *
364  * Returns 0 since it always succeeds.
365  */
366 static int mflo_func(struct pt_regs *regs, u32 ir)
367 {
368 	if (MIPSInst_RD(ir))
369 		regs->regs[MIPSInst_RD(ir)] = regs->lo;
370 
371 	MIPS_R2_STATS(hilo);
372 
373 	return 0;
374 }
375 
376 /**
377  * mtlo_func - Emulate a MTLO instruction
378  * @regs: Process register set
379  * @ir: Instruction
380  *
381  * Returns 0 since it always succeeds.
382  */
383 static int mtlo_func(struct pt_regs *regs, u32 ir)
384 {
385 	regs->lo = regs->regs[MIPSInst_RS(ir)];
386 
387 	MIPS_R2_STATS(hilo);
388 
389 	return 0;
390 }
391 
392 /**
393  * mult_func - Emulate a MULT instruction
394  * @regs: Process register set
395  * @ir: Instruction
396  *
397  * Returns 0 since it always succeeds.
398  */
399 static int mult_func(struct pt_regs *regs, u32 ir)
400 {
401 	s64 res;
402 	s32 rt, rs;
403 
404 	rt = regs->regs[MIPSInst_RT(ir)];
405 	rs = regs->regs[MIPSInst_RS(ir)];
406 	res = (s64)rt * (s64)rs;
407 
408 	rs = res;
409 	regs->lo = (s64)rs;
410 	rt = res >> 32;
411 	res = (s64)rt;
412 	regs->hi = res;
413 
414 	MIPS_R2_STATS(muls);
415 
416 	return 0;
417 }
418 
419 /**
420  * multu_func - Emulate a MULTU instruction
421  * @regs: Process register set
422  * @ir: Instruction
423  *
424  * Returns 0 since it always succeeds.
425  */
426 static int multu_func(struct pt_regs *regs, u32 ir)
427 {
428 	u64 res;
429 	u32 rt, rs;
430 
431 	rt = regs->regs[MIPSInst_RT(ir)];
432 	rs = regs->regs[MIPSInst_RS(ir)];
433 	res = (u64)rt * (u64)rs;
434 	rt = res;
435 	regs->lo = (s64)rt;
436 	regs->hi = (s64)(res >> 32);
437 
438 	MIPS_R2_STATS(muls);
439 
440 	return 0;
441 }
442 
443 /**
444  * div_func - Emulate a DIV instruction
445  * @regs: Process register set
446  * @ir: Instruction
447  *
448  * Returns 0 since it always succeeds.
449  */
450 static int div_func(struct pt_regs *regs, u32 ir)
451 {
452 	s32 rt, rs;
453 
454 	rt = regs->regs[MIPSInst_RT(ir)];
455 	rs = regs->regs[MIPSInst_RS(ir)];
456 
457 	regs->lo = (s64)(rs / rt);
458 	regs->hi = (s64)(rs % rt);
459 
460 	MIPS_R2_STATS(divs);
461 
462 	return 0;
463 }
464 
465 /**
466  * divu_func - Emulate a DIVU instruction
467  * @regs: Process register set
468  * @ir: Instruction
469  *
470  * Returns 0 since it always succeeds.
471  */
472 static int divu_func(struct pt_regs *regs, u32 ir)
473 {
474 	u32 rt, rs;
475 
476 	rt = regs->regs[MIPSInst_RT(ir)];
477 	rs = regs->regs[MIPSInst_RS(ir)];
478 
479 	regs->lo = (s64)(rs / rt);
480 	regs->hi = (s64)(rs % rt);
481 
482 	MIPS_R2_STATS(divs);
483 
484 	return 0;
485 }
486 
487 /**
488  * dmult_func - Emulate a DMULT instruction
489  * @regs: Process register set
490  * @ir: Instruction
491  *
492  * Returns 0 on success or SIGILL for 32-bit kernels.
493  */
494 static int dmult_func(struct pt_regs *regs, u32 ir)
495 {
496 	s64 res;
497 	s64 rt, rs;
498 
499 	if (config_enabled(CONFIG_32BIT))
500 		return SIGILL;
501 
502 	rt = regs->regs[MIPSInst_RT(ir)];
503 	rs = regs->regs[MIPSInst_RS(ir)];
504 	res = rt * rs;
505 
506 	regs->lo = res;
507 	__asm__ __volatile__(
508 		"dmuh %0, %1, %2\t\n"
509 		: "=r"(res)
510 		: "r"(rt), "r"(rs));
511 
512 	regs->hi = res;
513 
514 	MIPS_R2_STATS(muls);
515 
516 	return 0;
517 }
518 
519 /**
520  * dmultu_func - Emulate a DMULTU instruction
521  * @regs: Process register set
522  * @ir: Instruction
523  *
524  * Returns 0 on success or SIGILL for 32-bit kernels.
525  */
526 static int dmultu_func(struct pt_regs *regs, u32 ir)
527 {
528 	u64 res;
529 	u64 rt, rs;
530 
531 	if (config_enabled(CONFIG_32BIT))
532 		return SIGILL;
533 
534 	rt = regs->regs[MIPSInst_RT(ir)];
535 	rs = regs->regs[MIPSInst_RS(ir)];
536 	res = rt * rs;
537 
538 	regs->lo = res;
539 	__asm__ __volatile__(
540 		"dmuhu %0, %1, %2\t\n"
541 		: "=r"(res)
542 		: "r"(rt), "r"(rs));
543 
544 	regs->hi = res;
545 
546 	MIPS_R2_STATS(muls);
547 
548 	return 0;
549 }
550 
551 /**
552  * ddiv_func - Emulate a DDIV instruction
553  * @regs: Process register set
554  * @ir: Instruction
555  *
556  * Returns 0 on success or SIGILL for 32-bit kernels.
557  */
558 static int ddiv_func(struct pt_regs *regs, u32 ir)
559 {
560 	s64 rt, rs;
561 
562 	if (config_enabled(CONFIG_32BIT))
563 		return SIGILL;
564 
565 	rt = regs->regs[MIPSInst_RT(ir)];
566 	rs = regs->regs[MIPSInst_RS(ir)];
567 
568 	regs->lo = rs / rt;
569 	regs->hi = rs % rt;
570 
571 	MIPS_R2_STATS(divs);
572 
573 	return 0;
574 }
575 
576 /**
577  * ddivu_func - Emulate a DDIVU instruction
578  * @regs: Process register set
579  * @ir: Instruction
580  *
581  * Returns 0 on success or SIGILL for 32-bit kernels.
582  */
583 static int ddivu_func(struct pt_regs *regs, u32 ir)
584 {
585 	u64 rt, rs;
586 
587 	if (config_enabled(CONFIG_32BIT))
588 		return SIGILL;
589 
590 	rt = regs->regs[MIPSInst_RT(ir)];
591 	rs = regs->regs[MIPSInst_RS(ir)];
592 
593 	regs->lo = rs / rt;
594 	regs->hi = rs % rt;
595 
596 	MIPS_R2_STATS(divs);
597 
598 	return 0;
599 }
600 
601 /* R6 removed instructions for the SPECIAL opcode */
602 static struct r2_decoder_table spec_op_table[] = {
603 	{ 0xfc1ff83f, 0x00000008, jr_func },
604 	{ 0xfc00ffff, 0x00000018, mult_func },
605 	{ 0xfc00ffff, 0x00000019, multu_func },
606 	{ 0xfc00ffff, 0x0000001c, dmult_func },
607 	{ 0xfc00ffff, 0x0000001d, dmultu_func },
608 	{ 0xffff07ff, 0x00000010, mfhi_func },
609 	{ 0xfc1fffff, 0x00000011, mthi_func },
610 	{ 0xffff07ff, 0x00000012, mflo_func },
611 	{ 0xfc1fffff, 0x00000013, mtlo_func },
612 	{ 0xfc0307ff, 0x00000001, movf_func },
613 	{ 0xfc0307ff, 0x00010001, movt_func },
614 	{ 0xfc0007ff, 0x0000000a, movz_func },
615 	{ 0xfc0007ff, 0x0000000b, movn_func },
616 	{ 0xfc00ffff, 0x0000001a, div_func },
617 	{ 0xfc00ffff, 0x0000001b, divu_func },
618 	{ 0xfc00ffff, 0x0000001e, ddiv_func },
619 	{ 0xfc00ffff, 0x0000001f, ddivu_func },
620 	{}
621 };
622 
623 /**
624  * madd_func - Emulate a MADD instruction
625  * @regs: Process register set
626  * @ir: Instruction
627  *
628  * Returns 0 since it always succeeds.
629  */
630 static int madd_func(struct pt_regs *regs, u32 ir)
631 {
632 	s64 res;
633 	s32 rt, rs;
634 
635 	rt = regs->regs[MIPSInst_RT(ir)];
636 	rs = regs->regs[MIPSInst_RS(ir)];
637 	res = (s64)rt * (s64)rs;
638 	rt = regs->hi;
639 	rs = regs->lo;
640 	res += ((((s64)rt) << 32) | (u32)rs);
641 
642 	rt = res;
643 	regs->lo = (s64)rt;
644 	rs = res >> 32;
645 	regs->hi = (s64)rs;
646 
647 	MIPS_R2_STATS(dsps);
648 
649 	return 0;
650 }
651 
652 /**
653  * maddu_func - Emulate a MADDU instruction
654  * @regs: Process register set
655  * @ir: Instruction
656  *
657  * Returns 0 since it always succeeds.
658  */
659 static int maddu_func(struct pt_regs *regs, u32 ir)
660 {
661 	u64 res;
662 	u32 rt, rs;
663 
664 	rt = regs->regs[MIPSInst_RT(ir)];
665 	rs = regs->regs[MIPSInst_RS(ir)];
666 	res = (u64)rt * (u64)rs;
667 	rt = regs->hi;
668 	rs = regs->lo;
669 	res += ((((s64)rt) << 32) | (u32)rs);
670 
671 	rt = res;
672 	regs->lo = (s64)rt;
673 	rs = res >> 32;
674 	regs->hi = (s64)rs;
675 
676 	MIPS_R2_STATS(dsps);
677 
678 	return 0;
679 }
680 
681 /**
682  * msub_func - Emulate a MSUB instruction
683  * @regs: Process register set
684  * @ir: Instruction
685  *
686  * Returns 0 since it always succeeds.
687  */
688 static int msub_func(struct pt_regs *regs, u32 ir)
689 {
690 	s64 res;
691 	s32 rt, rs;
692 
693 	rt = regs->regs[MIPSInst_RT(ir)];
694 	rs = regs->regs[MIPSInst_RS(ir)];
695 	res = (s64)rt * (s64)rs;
696 	rt = regs->hi;
697 	rs = regs->lo;
698 	res = ((((s64)rt) << 32) | (u32)rs) - res;
699 
700 	rt = res;
701 	regs->lo = (s64)rt;
702 	rs = res >> 32;
703 	regs->hi = (s64)rs;
704 
705 	MIPS_R2_STATS(dsps);
706 
707 	return 0;
708 }
709 
710 /**
711  * msubu_func - Emulate a MSUBU instruction
712  * @regs: Process register set
713  * @ir: Instruction
714  *
715  * Returns 0 since it always succeeds.
716  */
717 static int msubu_func(struct pt_regs *regs, u32 ir)
718 {
719 	u64 res;
720 	u32 rt, rs;
721 
722 	rt = regs->regs[MIPSInst_RT(ir)];
723 	rs = regs->regs[MIPSInst_RS(ir)];
724 	res = (u64)rt * (u64)rs;
725 	rt = regs->hi;
726 	rs = regs->lo;
727 	res = ((((s64)rt) << 32) | (u32)rs) - res;
728 
729 	rt = res;
730 	regs->lo = (s64)rt;
731 	rs = res >> 32;
732 	regs->hi = (s64)rs;
733 
734 	MIPS_R2_STATS(dsps);
735 
736 	return 0;
737 }
738 
739 /**
740  * mul_func - Emulate a MUL instruction
741  * @regs: Process register set
742  * @ir: Instruction
743  *
744  * Returns 0 since it always succeeds.
745  */
746 static int mul_func(struct pt_regs *regs, u32 ir)
747 {
748 	s64 res;
749 	s32 rt, rs;
750 
751 	if (!MIPSInst_RD(ir))
752 		return 0;
753 	rt = regs->regs[MIPSInst_RT(ir)];
754 	rs = regs->regs[MIPSInst_RS(ir)];
755 	res = (s64)rt * (s64)rs;
756 
757 	rs = res;
758 	regs->regs[MIPSInst_RD(ir)] = (s64)rs;
759 
760 	MIPS_R2_STATS(muls);
761 
762 	return 0;
763 }
764 
765 /**
766  * clz_func - Emulate a CLZ instruction
767  * @regs: Process register set
768  * @ir: Instruction
769  *
770  * Returns 0 since it always succeeds.
771  */
772 static int clz_func(struct pt_regs *regs, u32 ir)
773 {
774 	u32 res;
775 	u32 rs;
776 
777 	if (!MIPSInst_RD(ir))
778 		return 0;
779 
780 	rs = regs->regs[MIPSInst_RS(ir)];
781 	__asm__ __volatile__("clz %0, %1" : "=r"(res) : "r"(rs));
782 	regs->regs[MIPSInst_RD(ir)] = res;
783 
784 	MIPS_R2_STATS(bops);
785 
786 	return 0;
787 }
788 
789 /**
790  * clo_func - Emulate a CLO instruction
791  * @regs: Process register set
792  * @ir: Instruction
793  *
794  * Returns 0 since it always succeeds.
795  */
796 
797 static int clo_func(struct pt_regs *regs, u32 ir)
798 {
799 	u32 res;
800 	u32 rs;
801 
802 	if (!MIPSInst_RD(ir))
803 		return 0;
804 
805 	rs = regs->regs[MIPSInst_RS(ir)];
806 	__asm__ __volatile__("clo %0, %1" : "=r"(res) : "r"(rs));
807 	regs->regs[MIPSInst_RD(ir)] = res;
808 
809 	MIPS_R2_STATS(bops);
810 
811 	return 0;
812 }
813 
814 /**
815  * dclz_func - Emulate a DCLZ instruction
816  * @regs: Process register set
817  * @ir: Instruction
818  *
819  * Returns 0 since it always succeeds.
820  */
821 static int dclz_func(struct pt_regs *regs, u32 ir)
822 {
823 	u64 res;
824 	u64 rs;
825 
826 	if (config_enabled(CONFIG_32BIT))
827 		return SIGILL;
828 
829 	if (!MIPSInst_RD(ir))
830 		return 0;
831 
832 	rs = regs->regs[MIPSInst_RS(ir)];
833 	__asm__ __volatile__("dclz %0, %1" : "=r"(res) : "r"(rs));
834 	regs->regs[MIPSInst_RD(ir)] = res;
835 
836 	MIPS_R2_STATS(bops);
837 
838 	return 0;
839 }
840 
841 /**
842  * dclo_func - Emulate a DCLO instruction
843  * @regs: Process register set
844  * @ir: Instruction
845  *
846  * Returns 0 since it always succeeds.
847  */
848 static int dclo_func(struct pt_regs *regs, u32 ir)
849 {
850 	u64 res;
851 	u64 rs;
852 
853 	if (config_enabled(CONFIG_32BIT))
854 		return SIGILL;
855 
856 	if (!MIPSInst_RD(ir))
857 		return 0;
858 
859 	rs = regs->regs[MIPSInst_RS(ir)];
860 	__asm__ __volatile__("dclo %0, %1" : "=r"(res) : "r"(rs));
861 	regs->regs[MIPSInst_RD(ir)] = res;
862 
863 	MIPS_R2_STATS(bops);
864 
865 	return 0;
866 }
867 
868 /* R6 removed instructions for the SPECIAL2 opcode */
869 static struct r2_decoder_table spec2_op_table[] = {
870 	{ 0xfc00ffff, 0x70000000, madd_func },
871 	{ 0xfc00ffff, 0x70000001, maddu_func },
872 	{ 0xfc0007ff, 0x70000002, mul_func },
873 	{ 0xfc00ffff, 0x70000004, msub_func },
874 	{ 0xfc00ffff, 0x70000005, msubu_func },
875 	{ 0xfc0007ff, 0x70000020, clz_func },
876 	{ 0xfc0007ff, 0x70000021, clo_func },
877 	{ 0xfc0007ff, 0x70000024, dclz_func },
878 	{ 0xfc0007ff, 0x70000025, dclo_func },
879 	{ }
880 };
881 
882 static inline int mipsr2_find_op_func(struct pt_regs *regs, u32 inst,
883 				      struct r2_decoder_table *table)
884 {
885 	struct r2_decoder_table *p;
886 	int err;
887 
888 	for (p = table; p->func; p++) {
889 		if ((inst & p->mask) == p->code) {
890 			err = (p->func)(regs, inst);
891 			return err;
892 		}
893 	}
894 	return SIGILL;
895 }
896 
897 /**
898  * mipsr2_decoder: Decode and emulate a MIPS R2 instruction
899  * @regs: Process register set
900  * @inst: Instruction to decode and emulate
901  * @fcr31: Floating Point Control and Status Register returned
902  */
903 int mipsr2_decoder(struct pt_regs *regs, u32 inst, unsigned long *fcr31)
904 {
905 	int err = 0;
906 	unsigned long vaddr;
907 	u32 nir;
908 	unsigned long cpc, epc, nepc, r31, res, rs, rt;
909 
910 	void __user *fault_addr = NULL;
911 	int pass = 0;
912 
913 repeat:
914 	r31 = regs->regs[31];
915 	epc = regs->cp0_epc;
916 	err = compute_return_epc(regs);
917 	if (err < 0) {
918 		BUG();
919 		return SIGEMT;
920 	}
921 	pr_debug("Emulating the 0x%08x R2 instruction @ 0x%08lx (pass=%d))\n",
922 		 inst, epc, pass);
923 
924 	switch (MIPSInst_OPCODE(inst)) {
925 	case spec_op:
926 		err = mipsr2_find_op_func(regs, inst, spec_op_table);
927 		if (err < 0) {
928 			/* FPU instruction under JR */
929 			regs->cp0_cause |= CAUSEF_BD;
930 			goto fpu_emul;
931 		}
932 		break;
933 	case spec2_op:
934 		err = mipsr2_find_op_func(regs, inst, spec2_op_table);
935 		break;
936 	case bcond_op:
937 		rt = MIPSInst_RT(inst);
938 		rs = MIPSInst_RS(inst);
939 		switch (rt) {
940 		case tgei_op:
941 			if ((long)regs->regs[rs] >= MIPSInst_SIMM(inst))
942 				do_trap_or_bp(regs, 0, "TGEI");
943 
944 			MIPS_R2_STATS(traps);
945 
946 			break;
947 		case tgeiu_op:
948 			if (regs->regs[rs] >= MIPSInst_UIMM(inst))
949 				do_trap_or_bp(regs, 0, "TGEIU");
950 
951 			MIPS_R2_STATS(traps);
952 
953 			break;
954 		case tlti_op:
955 			if ((long)regs->regs[rs] < MIPSInst_SIMM(inst))
956 				do_trap_or_bp(regs, 0, "TLTI");
957 
958 			MIPS_R2_STATS(traps);
959 
960 			break;
961 		case tltiu_op:
962 			if (regs->regs[rs] < MIPSInst_UIMM(inst))
963 				do_trap_or_bp(regs, 0, "TLTIU");
964 
965 			MIPS_R2_STATS(traps);
966 
967 			break;
968 		case teqi_op:
969 			if (regs->regs[rs] == MIPSInst_SIMM(inst))
970 				do_trap_or_bp(regs, 0, "TEQI");
971 
972 			MIPS_R2_STATS(traps);
973 
974 			break;
975 		case tnei_op:
976 			if (regs->regs[rs] != MIPSInst_SIMM(inst))
977 				do_trap_or_bp(regs, 0, "TNEI");
978 
979 			MIPS_R2_STATS(traps);
980 
981 			break;
982 		case bltzl_op:
983 		case bgezl_op:
984 		case bltzall_op:
985 		case bgezall_op:
986 			if (delay_slot(regs)) {
987 				err = SIGILL;
988 				break;
989 			}
990 			regs->regs[31] = r31;
991 			regs->cp0_epc = epc;
992 			err = __compute_return_epc(regs);
993 			if (err < 0)
994 				return SIGEMT;
995 			if (err != BRANCH_LIKELY_TAKEN)
996 				break;
997 			cpc = regs->cp0_epc;
998 			nepc = epc + 4;
999 			err = __get_user(nir, (u32 __user *)nepc);
1000 			if (err) {
1001 				err = SIGSEGV;
1002 				break;
1003 			}
1004 			/*
1005 			 * This will probably be optimized away when
1006 			 * CONFIG_DEBUG_FS is not enabled
1007 			 */
1008 			switch (rt) {
1009 			case bltzl_op:
1010 				MIPS_R2BR_STATS(bltzl);
1011 				break;
1012 			case bgezl_op:
1013 				MIPS_R2BR_STATS(bgezl);
1014 				break;
1015 			case bltzall_op:
1016 				MIPS_R2BR_STATS(bltzall);
1017 				break;
1018 			case bgezall_op:
1019 				MIPS_R2BR_STATS(bgezall);
1020 				break;
1021 			}
1022 
1023 			switch (MIPSInst_OPCODE(nir)) {
1024 			case cop1_op:
1025 			case cop1x_op:
1026 			case lwc1_op:
1027 			case swc1_op:
1028 				regs->cp0_cause |= CAUSEF_BD;
1029 				goto fpu_emul;
1030 			}
1031 			if (nir) {
1032 				err = mipsr6_emul(regs, nir);
1033 				if (err > 0) {
1034 					err = mips_dsemul(regs, nir, cpc);
1035 					if (err == SIGILL)
1036 						err = SIGEMT;
1037 					MIPS_R2_STATS(dsemul);
1038 				}
1039 			}
1040 			break;
1041 		case bltzal_op:
1042 		case bgezal_op:
1043 			if (delay_slot(regs)) {
1044 				err = SIGILL;
1045 				break;
1046 			}
1047 			regs->regs[31] = r31;
1048 			regs->cp0_epc = epc;
1049 			err = __compute_return_epc(regs);
1050 			if (err < 0)
1051 				return SIGEMT;
1052 			cpc = regs->cp0_epc;
1053 			nepc = epc + 4;
1054 			err = __get_user(nir, (u32 __user *)nepc);
1055 			if (err) {
1056 				err = SIGSEGV;
1057 				break;
1058 			}
1059 			/*
1060 			 * This will probably be optimized away when
1061 			 * CONFIG_DEBUG_FS is not enabled
1062 			 */
1063 			switch (rt) {
1064 			case bltzal_op:
1065 				MIPS_R2BR_STATS(bltzal);
1066 				break;
1067 			case bgezal_op:
1068 				MIPS_R2BR_STATS(bgezal);
1069 				break;
1070 			}
1071 
1072 			switch (MIPSInst_OPCODE(nir)) {
1073 			case cop1_op:
1074 			case cop1x_op:
1075 			case lwc1_op:
1076 			case swc1_op:
1077 				regs->cp0_cause |= CAUSEF_BD;
1078 				goto fpu_emul;
1079 			}
1080 			if (nir) {
1081 				err = mipsr6_emul(regs, nir);
1082 				if (err > 0) {
1083 					err = mips_dsemul(regs, nir, cpc);
1084 					if (err == SIGILL)
1085 						err = SIGEMT;
1086 					MIPS_R2_STATS(dsemul);
1087 				}
1088 			}
1089 			break;
1090 		default:
1091 			regs->regs[31] = r31;
1092 			regs->cp0_epc = epc;
1093 			err = SIGILL;
1094 			break;
1095 		}
1096 		break;
1097 
1098 	case beql_op:
1099 	case bnel_op:
1100 	case blezl_op:
1101 	case bgtzl_op:
1102 		if (delay_slot(regs)) {
1103 			err = SIGILL;
1104 			break;
1105 		}
1106 		regs->regs[31] = r31;
1107 		regs->cp0_epc = epc;
1108 		err = __compute_return_epc(regs);
1109 		if (err < 0)
1110 			return SIGEMT;
1111 		if (err != BRANCH_LIKELY_TAKEN)
1112 			break;
1113 		cpc = regs->cp0_epc;
1114 		nepc = epc + 4;
1115 		err = __get_user(nir, (u32 __user *)nepc);
1116 		if (err) {
1117 			err = SIGSEGV;
1118 			break;
1119 		}
1120 		/*
1121 		 * This will probably be optimized away when
1122 		 * CONFIG_DEBUG_FS is not enabled
1123 		 */
1124 		switch (MIPSInst_OPCODE(inst)) {
1125 		case beql_op:
1126 			MIPS_R2BR_STATS(beql);
1127 			break;
1128 		case bnel_op:
1129 			MIPS_R2BR_STATS(bnel);
1130 			break;
1131 		case blezl_op:
1132 			MIPS_R2BR_STATS(blezl);
1133 			break;
1134 		case bgtzl_op:
1135 			MIPS_R2BR_STATS(bgtzl);
1136 			break;
1137 		}
1138 
1139 		switch (MIPSInst_OPCODE(nir)) {
1140 		case cop1_op:
1141 		case cop1x_op:
1142 		case lwc1_op:
1143 		case swc1_op:
1144 			regs->cp0_cause |= CAUSEF_BD;
1145 			goto fpu_emul;
1146 		}
1147 		if (nir) {
1148 			err = mipsr6_emul(regs, nir);
1149 			if (err > 0) {
1150 				err = mips_dsemul(regs, nir, cpc);
1151 				if (err == SIGILL)
1152 					err = SIGEMT;
1153 				MIPS_R2_STATS(dsemul);
1154 			}
1155 		}
1156 		break;
1157 	case lwc1_op:
1158 	case swc1_op:
1159 	case cop1_op:
1160 	case cop1x_op:
1161 fpu_emul:
1162 		regs->regs[31] = r31;
1163 		regs->cp0_epc = epc;
1164 		if (!used_math()) {     /* First time FPU user.  */
1165 			err = init_fpu();
1166 			set_used_math();
1167 		}
1168 		lose_fpu(1);    /* Save FPU state for the emulator. */
1169 
1170 		err = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
1171 					       &fault_addr);
1172 		*fcr31 = current->thread.fpu.fcr31;
1173 
1174 		/*
1175 		 * We can't allow the emulated instruction to leave any of
1176 		 * the cause bits set in $fcr31.
1177 		 */
1178 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
1179 
1180 		/*
1181 		 * this is a tricky issue - lose_fpu() uses LL/SC atomics
1182 		 * if FPU is owned and effectively cancels user level LL/SC.
1183 		 * So, it could be logical to don't restore FPU ownership here.
1184 		 * But the sequence of multiple FPU instructions is much much
1185 		 * more often than LL-FPU-SC and I prefer loop here until
1186 		 * next scheduler cycle cancels FPU ownership
1187 		 */
1188 		own_fpu(1);	/* Restore FPU state. */
1189 
1190 		if (err)
1191 			current->thread.cp0_baduaddr = (unsigned long)fault_addr;
1192 
1193 		MIPS_R2_STATS(fpus);
1194 
1195 		break;
1196 
1197 	case lwl_op:
1198 		rt = regs->regs[MIPSInst_RT(inst)];
1199 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1200 		if (!access_ok(VERIFY_READ, vaddr, 4)) {
1201 			current->thread.cp0_baduaddr = vaddr;
1202 			err = SIGSEGV;
1203 			break;
1204 		}
1205 		__asm__ __volatile__(
1206 			"	.set	push\n"
1207 			"	.set	reorder\n"
1208 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1209 			"1:"	LB	"%1, 0(%2)\n"
1210 				INS	"%0, %1, 24, 8\n"
1211 			"	andi	%1, %2, 0x3\n"
1212 			"	beq	$0, %1, 9f\n"
1213 				ADDIU	"%2, %2, -1\n"
1214 			"2:"	LB	"%1, 0(%2)\n"
1215 				INS	"%0, %1, 16, 8\n"
1216 			"	andi	%1, %2, 0x3\n"
1217 			"	beq	$0, %1, 9f\n"
1218 				ADDIU	"%2, %2, -1\n"
1219 			"3:"	LB	"%1, 0(%2)\n"
1220 				INS	"%0, %1, 8, 8\n"
1221 			"	andi	%1, %2, 0x3\n"
1222 			"	beq	$0, %1, 9f\n"
1223 				ADDIU	"%2, %2, -1\n"
1224 			"4:"	LB	"%1, 0(%2)\n"
1225 				INS	"%0, %1, 0, 8\n"
1226 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1227 			"1:"	LB	"%1, 0(%2)\n"
1228 				INS	"%0, %1, 24, 8\n"
1229 				ADDIU	"%2, %2, 1\n"
1230 			"	andi	%1, %2, 0x3\n"
1231 			"	beq	$0, %1, 9f\n"
1232 			"2:"	LB	"%1, 0(%2)\n"
1233 				INS	"%0, %1, 16, 8\n"
1234 				ADDIU	"%2, %2, 1\n"
1235 			"	andi	%1, %2, 0x3\n"
1236 			"	beq	$0, %1, 9f\n"
1237 			"3:"	LB	"%1, 0(%2)\n"
1238 				INS	"%0, %1, 8, 8\n"
1239 				ADDIU	"%2, %2, 1\n"
1240 			"	andi	%1, %2, 0x3\n"
1241 			"	beq	$0, %1, 9f\n"
1242 			"4:"	LB	"%1, 0(%2)\n"
1243 				INS	"%0, %1, 0, 8\n"
1244 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1245 			"9:	sll	%0, %0, 0\n"
1246 			"10:\n"
1247 			"	.insn\n"
1248 			"	.section	.fixup,\"ax\"\n"
1249 			"8:	li	%3,%4\n"
1250 			"	j	10b\n"
1251 			"	.previous\n"
1252 			"	.section	__ex_table,\"a\"\n"
1253 			"	.word	1b,8b\n"
1254 			"	.word	2b,8b\n"
1255 			"	.word	3b,8b\n"
1256 			"	.word	4b,8b\n"
1257 			"	.previous\n"
1258 			"	.set	pop\n"
1259 			: "+&r"(rt), "=&r"(rs),
1260 			  "+&r"(vaddr), "+&r"(err)
1261 			: "i"(SIGSEGV));
1262 
1263 		if (MIPSInst_RT(inst) && !err)
1264 			regs->regs[MIPSInst_RT(inst)] = rt;
1265 
1266 		MIPS_R2_STATS(loads);
1267 
1268 		break;
1269 
1270 	case lwr_op:
1271 		rt = regs->regs[MIPSInst_RT(inst)];
1272 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1273 		if (!access_ok(VERIFY_READ, vaddr, 4)) {
1274 			current->thread.cp0_baduaddr = vaddr;
1275 			err = SIGSEGV;
1276 			break;
1277 		}
1278 		__asm__ __volatile__(
1279 			"       .set	push\n"
1280 			"       .set	reorder\n"
1281 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1282 			"1:"    LB	"%1, 0(%2)\n"
1283 				INS	"%0, %1, 0, 8\n"
1284 				ADDIU	"%2, %2, 1\n"
1285 			"       andi	%1, %2, 0x3\n"
1286 			"       beq	$0, %1, 9f\n"
1287 			"2:"    LB	"%1, 0(%2)\n"
1288 				INS	"%0, %1, 8, 8\n"
1289 				ADDIU	"%2, %2, 1\n"
1290 			"       andi	%1, %2, 0x3\n"
1291 			"       beq	$0, %1, 9f\n"
1292 			"3:"    LB	"%1, 0(%2)\n"
1293 				INS	"%0, %1, 16, 8\n"
1294 				ADDIU	"%2, %2, 1\n"
1295 			"       andi	%1, %2, 0x3\n"
1296 			"       beq	$0, %1, 9f\n"
1297 			"4:"    LB	"%1, 0(%2)\n"
1298 				INS	"%0, %1, 24, 8\n"
1299 			"       sll	%0, %0, 0\n"
1300 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1301 			"1:"    LB	"%1, 0(%2)\n"
1302 				INS	"%0, %1, 0, 8\n"
1303 			"       andi	%1, %2, 0x3\n"
1304 			"       beq	$0, %1, 9f\n"
1305 				ADDIU	"%2, %2, -1\n"
1306 			"2:"    LB	"%1, 0(%2)\n"
1307 				INS	"%0, %1, 8, 8\n"
1308 			"       andi	%1, %2, 0x3\n"
1309 			"       beq	$0, %1, 9f\n"
1310 				ADDIU	"%2, %2, -1\n"
1311 			"3:"    LB	"%1, 0(%2)\n"
1312 				INS	"%0, %1, 16, 8\n"
1313 			"       andi	%1, %2, 0x3\n"
1314 			"       beq	$0, %1, 9f\n"
1315 				ADDIU	"%2, %2, -1\n"
1316 			"4:"    LB	"%1, 0(%2)\n"
1317 				INS	"%0, %1, 24, 8\n"
1318 			"       sll	%0, %0, 0\n"
1319 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1320 			"9:\n"
1321 			"10:\n"
1322 			"	.insn\n"
1323 			"	.section	.fixup,\"ax\"\n"
1324 			"8:	li	%3,%4\n"
1325 			"	j	10b\n"
1326 			"       .previous\n"
1327 			"	.section	__ex_table,\"a\"\n"
1328 			"	.word	1b,8b\n"
1329 			"	.word	2b,8b\n"
1330 			"	.word	3b,8b\n"
1331 			"	.word	4b,8b\n"
1332 			"	.previous\n"
1333 			"	.set	pop\n"
1334 			: "+&r"(rt), "=&r"(rs),
1335 			  "+&r"(vaddr), "+&r"(err)
1336 			: "i"(SIGSEGV));
1337 		if (MIPSInst_RT(inst) && !err)
1338 			regs->regs[MIPSInst_RT(inst)] = rt;
1339 
1340 		MIPS_R2_STATS(loads);
1341 
1342 		break;
1343 
1344 	case swl_op:
1345 		rt = regs->regs[MIPSInst_RT(inst)];
1346 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1347 		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
1348 			current->thread.cp0_baduaddr = vaddr;
1349 			err = SIGSEGV;
1350 			break;
1351 		}
1352 		__asm__ __volatile__(
1353 			"	.set	push\n"
1354 			"	.set	reorder\n"
1355 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1356 				EXT	"%1, %0, 24, 8\n"
1357 			"1:"	SB	"%1, 0(%2)\n"
1358 			"	andi	%1, %2, 0x3\n"
1359 			"	beq	$0, %1, 9f\n"
1360 				ADDIU	"%2, %2, -1\n"
1361 				EXT	"%1, %0, 16, 8\n"
1362 			"2:"	SB	"%1, 0(%2)\n"
1363 			"	andi	%1, %2, 0x3\n"
1364 			"	beq	$0, %1, 9f\n"
1365 				ADDIU	"%2, %2, -1\n"
1366 				EXT	"%1, %0, 8, 8\n"
1367 			"3:"	SB	"%1, 0(%2)\n"
1368 			"	andi	%1, %2, 0x3\n"
1369 			"	beq	$0, %1, 9f\n"
1370 				ADDIU	"%2, %2, -1\n"
1371 				EXT	"%1, %0, 0, 8\n"
1372 			"4:"	SB	"%1, 0(%2)\n"
1373 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1374 				EXT	"%1, %0, 24, 8\n"
1375 			"1:"	SB	"%1, 0(%2)\n"
1376 				ADDIU	"%2, %2, 1\n"
1377 			"	andi	%1, %2, 0x3\n"
1378 			"	beq	$0, %1, 9f\n"
1379 				EXT	"%1, %0, 16, 8\n"
1380 			"2:"	SB	"%1, 0(%2)\n"
1381 				ADDIU	"%2, %2, 1\n"
1382 			"	andi	%1, %2, 0x3\n"
1383 			"	beq	$0, %1, 9f\n"
1384 				EXT	"%1, %0, 8, 8\n"
1385 			"3:"	SB	"%1, 0(%2)\n"
1386 				ADDIU	"%2, %2, 1\n"
1387 			"	andi	%1, %2, 0x3\n"
1388 			"	beq	$0, %1, 9f\n"
1389 				EXT	"%1, %0, 0, 8\n"
1390 			"4:"	SB	"%1, 0(%2)\n"
1391 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1392 			"9:\n"
1393 			"	.insn\n"
1394 			"       .section        .fixup,\"ax\"\n"
1395 			"8:	li	%3,%4\n"
1396 			"	j	9b\n"
1397 			"	.previous\n"
1398 			"	.section        __ex_table,\"a\"\n"
1399 			"	.word	1b,8b\n"
1400 			"	.word	2b,8b\n"
1401 			"	.word	3b,8b\n"
1402 			"	.word	4b,8b\n"
1403 			"	.previous\n"
1404 			"	.set	pop\n"
1405 			: "+&r"(rt), "=&r"(rs),
1406 			  "+&r"(vaddr), "+&r"(err)
1407 			: "i"(SIGSEGV)
1408 			: "memory");
1409 
1410 		MIPS_R2_STATS(stores);
1411 
1412 		break;
1413 
1414 	case swr_op:
1415 		rt = regs->regs[MIPSInst_RT(inst)];
1416 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1417 		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
1418 			current->thread.cp0_baduaddr = vaddr;
1419 			err = SIGSEGV;
1420 			break;
1421 		}
1422 		__asm__ __volatile__(
1423 			"	.set	push\n"
1424 			"	.set	reorder\n"
1425 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1426 				EXT	"%1, %0, 0, 8\n"
1427 			"1:"	SB	"%1, 0(%2)\n"
1428 				ADDIU	"%2, %2, 1\n"
1429 			"	andi	%1, %2, 0x3\n"
1430 			"	beq	$0, %1, 9f\n"
1431 				EXT	"%1, %0, 8, 8\n"
1432 			"2:"	SB	"%1, 0(%2)\n"
1433 				ADDIU	"%2, %2, 1\n"
1434 			"	andi	%1, %2, 0x3\n"
1435 			"	beq	$0, %1, 9f\n"
1436 				EXT	"%1, %0, 16, 8\n"
1437 			"3:"	SB	"%1, 0(%2)\n"
1438 				ADDIU	"%2, %2, 1\n"
1439 			"	andi	%1, %2, 0x3\n"
1440 			"	beq	$0, %1, 9f\n"
1441 				EXT	"%1, %0, 24, 8\n"
1442 			"4:"	SB	"%1, 0(%2)\n"
1443 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1444 				EXT	"%1, %0, 0, 8\n"
1445 			"1:"	SB	"%1, 0(%2)\n"
1446 			"	andi	%1, %2, 0x3\n"
1447 			"	beq	$0, %1, 9f\n"
1448 				ADDIU	"%2, %2, -1\n"
1449 				EXT	"%1, %0, 8, 8\n"
1450 			"2:"	SB	"%1, 0(%2)\n"
1451 			"	andi	%1, %2, 0x3\n"
1452 			"	beq	$0, %1, 9f\n"
1453 				ADDIU	"%2, %2, -1\n"
1454 				EXT	"%1, %0, 16, 8\n"
1455 			"3:"	SB	"%1, 0(%2)\n"
1456 			"	andi	%1, %2, 0x3\n"
1457 			"	beq	$0, %1, 9f\n"
1458 				ADDIU	"%2, %2, -1\n"
1459 				EXT	"%1, %0, 24, 8\n"
1460 			"4:"	SB	"%1, 0(%2)\n"
1461 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1462 			"9:\n"
1463 			"	.insn\n"
1464 			"	.section        .fixup,\"ax\"\n"
1465 			"8:	li	%3,%4\n"
1466 			"	j	9b\n"
1467 			"	.previous\n"
1468 			"	.section        __ex_table,\"a\"\n"
1469 			"	.word	1b,8b\n"
1470 			"	.word	2b,8b\n"
1471 			"	.word	3b,8b\n"
1472 			"	.word	4b,8b\n"
1473 			"	.previous\n"
1474 			"	.set	pop\n"
1475 			: "+&r"(rt), "=&r"(rs),
1476 			  "+&r"(vaddr), "+&r"(err)
1477 			: "i"(SIGSEGV)
1478 			: "memory");
1479 
1480 		MIPS_R2_STATS(stores);
1481 
1482 		break;
1483 
1484 	case ldl_op:
1485 		if (config_enabled(CONFIG_32BIT)) {
1486 		    err = SIGILL;
1487 		    break;
1488 		}
1489 
1490 		rt = regs->regs[MIPSInst_RT(inst)];
1491 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1492 		if (!access_ok(VERIFY_READ, vaddr, 8)) {
1493 			current->thread.cp0_baduaddr = vaddr;
1494 			err = SIGSEGV;
1495 			break;
1496 		}
1497 		__asm__ __volatile__(
1498 			"	.set    push\n"
1499 			"	.set    reorder\n"
1500 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1501 			"1:	lb	%1, 0(%2)\n"
1502 			"	dinsu	%0, %1, 56, 8\n"
1503 			"	andi	%1, %2, 0x7\n"
1504 			"	beq	$0, %1, 9f\n"
1505 			"	daddiu	%2, %2, -1\n"
1506 			"2:	lb	%1, 0(%2)\n"
1507 			"	dinsu	%0, %1, 48, 8\n"
1508 			"	andi	%1, %2, 0x7\n"
1509 			"	beq	$0, %1, 9f\n"
1510 			"	daddiu	%2, %2, -1\n"
1511 			"3:	lb	%1, 0(%2)\n"
1512 			"	dinsu	%0, %1, 40, 8\n"
1513 			"	andi	%1, %2, 0x7\n"
1514 			"	beq	$0, %1, 9f\n"
1515 			"	daddiu	%2, %2, -1\n"
1516 			"4:	lb	%1, 0(%2)\n"
1517 			"	dinsu	%0, %1, 32, 8\n"
1518 			"	andi	%1, %2, 0x7\n"
1519 			"	beq	$0, %1, 9f\n"
1520 			"	daddiu	%2, %2, -1\n"
1521 			"5:	lb	%1, 0(%2)\n"
1522 			"	dins	%0, %1, 24, 8\n"
1523 			"	andi	%1, %2, 0x7\n"
1524 			"	beq	$0, %1, 9f\n"
1525 			"	daddiu	%2, %2, -1\n"
1526 			"6:	lb	%1, 0(%2)\n"
1527 			"	dins	%0, %1, 16, 8\n"
1528 			"	andi	%1, %2, 0x7\n"
1529 			"	beq	$0, %1, 9f\n"
1530 			"	daddiu	%2, %2, -1\n"
1531 			"7:	lb	%1, 0(%2)\n"
1532 			"	dins	%0, %1, 8, 8\n"
1533 			"	andi	%1, %2, 0x7\n"
1534 			"	beq	$0, %1, 9f\n"
1535 			"	daddiu	%2, %2, -1\n"
1536 			"0:	lb	%1, 0(%2)\n"
1537 			"	dins	%0, %1, 0, 8\n"
1538 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1539 			"1:	lb	%1, 0(%2)\n"
1540 			"	dinsu	%0, %1, 56, 8\n"
1541 			"	daddiu	%2, %2, 1\n"
1542 			"	andi	%1, %2, 0x7\n"
1543 			"	beq	$0, %1, 9f\n"
1544 			"2:	lb	%1, 0(%2)\n"
1545 			"	dinsu	%0, %1, 48, 8\n"
1546 			"	daddiu	%2, %2, 1\n"
1547 			"	andi	%1, %2, 0x7\n"
1548 			"	beq	$0, %1, 9f\n"
1549 			"3:	lb	%1, 0(%2)\n"
1550 			"	dinsu	%0, %1, 40, 8\n"
1551 			"	daddiu  %2, %2, 1\n"
1552 			"	andi	%1, %2, 0x7\n"
1553 			"	beq	$0, %1, 9f\n"
1554 			"4:	lb	%1, 0(%2)\n"
1555 			"	dinsu	%0, %1, 32, 8\n"
1556 			"	daddiu	%2, %2, 1\n"
1557 			"	andi	%1, %2, 0x7\n"
1558 			"	beq	$0, %1, 9f\n"
1559 			"5:	lb	%1, 0(%2)\n"
1560 			"	dins	%0, %1, 24, 8\n"
1561 			"	daddiu	%2, %2, 1\n"
1562 			"	andi	%1, %2, 0x7\n"
1563 			"	beq	$0, %1, 9f\n"
1564 			"6:	lb	%1, 0(%2)\n"
1565 			"	dins	%0, %1, 16, 8\n"
1566 			"	daddiu	%2, %2, 1\n"
1567 			"	andi	%1, %2, 0x7\n"
1568 			"	beq	$0, %1, 9f\n"
1569 			"7:	lb	%1, 0(%2)\n"
1570 			"	dins	%0, %1, 8, 8\n"
1571 			"	daddiu	%2, %2, 1\n"
1572 			"	andi	%1, %2, 0x7\n"
1573 			"	beq	$0, %1, 9f\n"
1574 			"0:	lb	%1, 0(%2)\n"
1575 			"	dins	%0, %1, 0, 8\n"
1576 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1577 			"9:\n"
1578 			"	.insn\n"
1579 			"	.section        .fixup,\"ax\"\n"
1580 			"8:	li	%3,%4\n"
1581 			"	j	9b\n"
1582 			"	.previous\n"
1583 			"	.section        __ex_table,\"a\"\n"
1584 			"	.word	1b,8b\n"
1585 			"	.word	2b,8b\n"
1586 			"	.word	3b,8b\n"
1587 			"	.word	4b,8b\n"
1588 			"	.word	5b,8b\n"
1589 			"	.word	6b,8b\n"
1590 			"	.word	7b,8b\n"
1591 			"	.word	0b,8b\n"
1592 			"	.previous\n"
1593 			"	.set	pop\n"
1594 			: "+&r"(rt), "=&r"(rs),
1595 			  "+&r"(vaddr), "+&r"(err)
1596 			: "i"(SIGSEGV));
1597 		if (MIPSInst_RT(inst) && !err)
1598 			regs->regs[MIPSInst_RT(inst)] = rt;
1599 
1600 		MIPS_R2_STATS(loads);
1601 		break;
1602 
1603 	case ldr_op:
1604 		if (config_enabled(CONFIG_32BIT)) {
1605 		    err = SIGILL;
1606 		    break;
1607 		}
1608 
1609 		rt = regs->regs[MIPSInst_RT(inst)];
1610 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1611 		if (!access_ok(VERIFY_READ, vaddr, 8)) {
1612 			current->thread.cp0_baduaddr = vaddr;
1613 			err = SIGSEGV;
1614 			break;
1615 		}
1616 		__asm__ __volatile__(
1617 			"	.set    push\n"
1618 			"	.set    reorder\n"
1619 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1620 			"1:	lb      %1, 0(%2)\n"
1621 			"	dins   %0, %1, 0, 8\n"
1622 			"	daddiu  %2, %2, 1\n"
1623 			"	andi    %1, %2, 0x7\n"
1624 			"	beq     $0, %1, 9f\n"
1625 			"2:	lb      %1, 0(%2)\n"
1626 			"	dins   %0, %1, 8, 8\n"
1627 			"	daddiu  %2, %2, 1\n"
1628 			"	andi    %1, %2, 0x7\n"
1629 			"	beq     $0, %1, 9f\n"
1630 			"3:	lb      %1, 0(%2)\n"
1631 			"	dins   %0, %1, 16, 8\n"
1632 			"	daddiu  %2, %2, 1\n"
1633 			"	andi    %1, %2, 0x7\n"
1634 			"	beq     $0, %1, 9f\n"
1635 			"4:	lb      %1, 0(%2)\n"
1636 			"	dins   %0, %1, 24, 8\n"
1637 			"	daddiu  %2, %2, 1\n"
1638 			"	andi    %1, %2, 0x7\n"
1639 			"	beq     $0, %1, 9f\n"
1640 			"5:	lb      %1, 0(%2)\n"
1641 			"	dinsu    %0, %1, 32, 8\n"
1642 			"	daddiu  %2, %2, 1\n"
1643 			"	andi    %1, %2, 0x7\n"
1644 			"	beq     $0, %1, 9f\n"
1645 			"6:	lb      %1, 0(%2)\n"
1646 			"	dinsu    %0, %1, 40, 8\n"
1647 			"	daddiu  %2, %2, 1\n"
1648 			"	andi    %1, %2, 0x7\n"
1649 			"	beq     $0, %1, 9f\n"
1650 			"7:	lb      %1, 0(%2)\n"
1651 			"	dinsu    %0, %1, 48, 8\n"
1652 			"	daddiu  %2, %2, 1\n"
1653 			"	andi    %1, %2, 0x7\n"
1654 			"	beq     $0, %1, 9f\n"
1655 			"0:	lb      %1, 0(%2)\n"
1656 			"	dinsu    %0, %1, 56, 8\n"
1657 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1658 			"1:	lb      %1, 0(%2)\n"
1659 			"	dins   %0, %1, 0, 8\n"
1660 			"	andi    %1, %2, 0x7\n"
1661 			"	beq     $0, %1, 9f\n"
1662 			"	daddiu  %2, %2, -1\n"
1663 			"2:	lb      %1, 0(%2)\n"
1664 			"	dins   %0, %1, 8, 8\n"
1665 			"	andi    %1, %2, 0x7\n"
1666 			"	beq     $0, %1, 9f\n"
1667 			"	daddiu  %2, %2, -1\n"
1668 			"3:	lb      %1, 0(%2)\n"
1669 			"	dins   %0, %1, 16, 8\n"
1670 			"	andi    %1, %2, 0x7\n"
1671 			"	beq     $0, %1, 9f\n"
1672 			"	daddiu  %2, %2, -1\n"
1673 			"4:	lb      %1, 0(%2)\n"
1674 			"	dins   %0, %1, 24, 8\n"
1675 			"	andi    %1, %2, 0x7\n"
1676 			"	beq     $0, %1, 9f\n"
1677 			"	daddiu  %2, %2, -1\n"
1678 			"5:	lb      %1, 0(%2)\n"
1679 			"	dinsu    %0, %1, 32, 8\n"
1680 			"	andi    %1, %2, 0x7\n"
1681 			"	beq     $0, %1, 9f\n"
1682 			"	daddiu  %2, %2, -1\n"
1683 			"6:	lb      %1, 0(%2)\n"
1684 			"	dinsu    %0, %1, 40, 8\n"
1685 			"	andi    %1, %2, 0x7\n"
1686 			"	beq     $0, %1, 9f\n"
1687 			"	daddiu  %2, %2, -1\n"
1688 			"7:	lb      %1, 0(%2)\n"
1689 			"	dinsu    %0, %1, 48, 8\n"
1690 			"	andi    %1, %2, 0x7\n"
1691 			"	beq     $0, %1, 9f\n"
1692 			"	daddiu  %2, %2, -1\n"
1693 			"0:	lb      %1, 0(%2)\n"
1694 			"	dinsu    %0, %1, 56, 8\n"
1695 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1696 			"9:\n"
1697 			"	.insn\n"
1698 			"	.section        .fixup,\"ax\"\n"
1699 			"8:	li     %3,%4\n"
1700 			"	j      9b\n"
1701 			"	.previous\n"
1702 			"	.section        __ex_table,\"a\"\n"
1703 			"	.word  1b,8b\n"
1704 			"	.word  2b,8b\n"
1705 			"	.word  3b,8b\n"
1706 			"	.word  4b,8b\n"
1707 			"	.word  5b,8b\n"
1708 			"	.word  6b,8b\n"
1709 			"	.word  7b,8b\n"
1710 			"	.word  0b,8b\n"
1711 			"	.previous\n"
1712 			"	.set    pop\n"
1713 			: "+&r"(rt), "=&r"(rs),
1714 			  "+&r"(vaddr), "+&r"(err)
1715 			: "i"(SIGSEGV));
1716 		if (MIPSInst_RT(inst) && !err)
1717 			regs->regs[MIPSInst_RT(inst)] = rt;
1718 
1719 		MIPS_R2_STATS(loads);
1720 		break;
1721 
1722 	case sdl_op:
1723 		if (config_enabled(CONFIG_32BIT)) {
1724 		    err = SIGILL;
1725 		    break;
1726 		}
1727 
1728 		rt = regs->regs[MIPSInst_RT(inst)];
1729 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1730 		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
1731 			current->thread.cp0_baduaddr = vaddr;
1732 			err = SIGSEGV;
1733 			break;
1734 		}
1735 		__asm__ __volatile__(
1736 			"	.set	push\n"
1737 			"	.set	reorder\n"
1738 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1739 			"	dextu	%1, %0, 56, 8\n"
1740 			"1:	sb	%1, 0(%2)\n"
1741 			"	andi	%1, %2, 0x7\n"
1742 			"	beq	$0, %1, 9f\n"
1743 			"	daddiu	%2, %2, -1\n"
1744 			"	dextu	%1, %0, 48, 8\n"
1745 			"2:	sb	%1, 0(%2)\n"
1746 			"	andi	%1, %2, 0x7\n"
1747 			"	beq	$0, %1, 9f\n"
1748 			"	daddiu	%2, %2, -1\n"
1749 			"	dextu	%1, %0, 40, 8\n"
1750 			"3:	sb	%1, 0(%2)\n"
1751 			"	andi	%1, %2, 0x7\n"
1752 			"	beq	$0, %1, 9f\n"
1753 			"	daddiu	%2, %2, -1\n"
1754 			"	dextu	%1, %0, 32, 8\n"
1755 			"4:	sb	%1, 0(%2)\n"
1756 			"	andi	%1, %2, 0x7\n"
1757 			"	beq	$0, %1, 9f\n"
1758 			"	daddiu	%2, %2, -1\n"
1759 			"	dext	%1, %0, 24, 8\n"
1760 			"5:	sb	%1, 0(%2)\n"
1761 			"	andi	%1, %2, 0x7\n"
1762 			"	beq	$0, %1, 9f\n"
1763 			"	daddiu	%2, %2, -1\n"
1764 			"	dext	%1, %0, 16, 8\n"
1765 			"6:	sb	%1, 0(%2)\n"
1766 			"	andi	%1, %2, 0x7\n"
1767 			"	beq	$0, %1, 9f\n"
1768 			"	daddiu	%2, %2, -1\n"
1769 			"	dext	%1, %0, 8, 8\n"
1770 			"7:	sb	%1, 0(%2)\n"
1771 			"	andi	%1, %2, 0x7\n"
1772 			"	beq	$0, %1, 9f\n"
1773 			"	daddiu	%2, %2, -1\n"
1774 			"	dext	%1, %0, 0, 8\n"
1775 			"0:	sb	%1, 0(%2)\n"
1776 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1777 			"	dextu	%1, %0, 56, 8\n"
1778 			"1:	sb	%1, 0(%2)\n"
1779 			"	daddiu	%2, %2, 1\n"
1780 			"	andi	%1, %2, 0x7\n"
1781 			"	beq	$0, %1, 9f\n"
1782 			"	dextu	%1, %0, 48, 8\n"
1783 			"2:	sb	%1, 0(%2)\n"
1784 			"	daddiu	%2, %2, 1\n"
1785 			"	andi	%1, %2, 0x7\n"
1786 			"	beq	$0, %1, 9f\n"
1787 			"	dextu	%1, %0, 40, 8\n"
1788 			"3:	sb	%1, 0(%2)\n"
1789 			"	daddiu	%2, %2, 1\n"
1790 			"	andi	%1, %2, 0x7\n"
1791 			"	beq	$0, %1, 9f\n"
1792 			"	dextu	%1, %0, 32, 8\n"
1793 			"4:	sb	%1, 0(%2)\n"
1794 			"	daddiu	%2, %2, 1\n"
1795 			"	andi	%1, %2, 0x7\n"
1796 			"	beq	$0, %1, 9f\n"
1797 			"	dext	%1, %0, 24, 8\n"
1798 			"5:	sb	%1, 0(%2)\n"
1799 			"	daddiu	%2, %2, 1\n"
1800 			"	andi	%1, %2, 0x7\n"
1801 			"	beq	$0, %1, 9f\n"
1802 			"	dext	%1, %0, 16, 8\n"
1803 			"6:	sb	%1, 0(%2)\n"
1804 			"	daddiu	%2, %2, 1\n"
1805 			"	andi	%1, %2, 0x7\n"
1806 			"	beq	$0, %1, 9f\n"
1807 			"	dext	%1, %0, 8, 8\n"
1808 			"7:	sb	%1, 0(%2)\n"
1809 			"	daddiu	%2, %2, 1\n"
1810 			"	andi	%1, %2, 0x7\n"
1811 			"	beq	$0, %1, 9f\n"
1812 			"	dext	%1, %0, 0, 8\n"
1813 			"0:	sb	%1, 0(%2)\n"
1814 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1815 			"9:\n"
1816 			"	.insn\n"
1817 			"	.section        .fixup,\"ax\"\n"
1818 			"8:	li	%3,%4\n"
1819 			"	j	9b\n"
1820 			"	.previous\n"
1821 			"	.section        __ex_table,\"a\"\n"
1822 			"	.word	1b,8b\n"
1823 			"	.word	2b,8b\n"
1824 			"	.word	3b,8b\n"
1825 			"	.word	4b,8b\n"
1826 			"	.word	5b,8b\n"
1827 			"	.word	6b,8b\n"
1828 			"	.word	7b,8b\n"
1829 			"	.word	0b,8b\n"
1830 			"	.previous\n"
1831 			"	.set	pop\n"
1832 			: "+&r"(rt), "=&r"(rs),
1833 			  "+&r"(vaddr), "+&r"(err)
1834 			: "i"(SIGSEGV)
1835 			: "memory");
1836 
1837 		MIPS_R2_STATS(stores);
1838 		break;
1839 
1840 	case sdr_op:
1841 		if (config_enabled(CONFIG_32BIT)) {
1842 		    err = SIGILL;
1843 		    break;
1844 		}
1845 
1846 		rt = regs->regs[MIPSInst_RT(inst)];
1847 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1848 		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
1849 			current->thread.cp0_baduaddr = vaddr;
1850 			err = SIGSEGV;
1851 			break;
1852 		}
1853 		__asm__ __volatile__(
1854 			"       .set	push\n"
1855 			"       .set	reorder\n"
1856 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1857 			"       dext	%1, %0, 0, 8\n"
1858 			"1:     sb	%1, 0(%2)\n"
1859 			"       daddiu	%2, %2, 1\n"
1860 			"       andi	%1, %2, 0x7\n"
1861 			"       beq	$0, %1, 9f\n"
1862 			"       dext	%1, %0, 8, 8\n"
1863 			"2:     sb	%1, 0(%2)\n"
1864 			"       daddiu	%2, %2, 1\n"
1865 			"       andi	%1, %2, 0x7\n"
1866 			"       beq	$0, %1, 9f\n"
1867 			"       dext	%1, %0, 16, 8\n"
1868 			"3:     sb	%1, 0(%2)\n"
1869 			"       daddiu	%2, %2, 1\n"
1870 			"       andi	%1, %2, 0x7\n"
1871 			"       beq	$0, %1, 9f\n"
1872 			"       dext	%1, %0, 24, 8\n"
1873 			"4:     sb	%1, 0(%2)\n"
1874 			"       daddiu	%2, %2, 1\n"
1875 			"       andi	%1, %2, 0x7\n"
1876 			"       beq	$0, %1, 9f\n"
1877 			"       dextu	%1, %0, 32, 8\n"
1878 			"5:     sb	%1, 0(%2)\n"
1879 			"       daddiu	%2, %2, 1\n"
1880 			"       andi	%1, %2, 0x7\n"
1881 			"       beq	$0, %1, 9f\n"
1882 			"       dextu	%1, %0, 40, 8\n"
1883 			"6:     sb	%1, 0(%2)\n"
1884 			"       daddiu	%2, %2, 1\n"
1885 			"       andi	%1, %2, 0x7\n"
1886 			"       beq	$0, %1, 9f\n"
1887 			"       dextu	%1, %0, 48, 8\n"
1888 			"7:     sb	%1, 0(%2)\n"
1889 			"       daddiu	%2, %2, 1\n"
1890 			"       andi	%1, %2, 0x7\n"
1891 			"       beq	$0, %1, 9f\n"
1892 			"       dextu	%1, %0, 56, 8\n"
1893 			"0:     sb	%1, 0(%2)\n"
1894 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1895 			"       dext	%1, %0, 0, 8\n"
1896 			"1:     sb	%1, 0(%2)\n"
1897 			"       andi	%1, %2, 0x7\n"
1898 			"       beq	$0, %1, 9f\n"
1899 			"       daddiu	%2, %2, -1\n"
1900 			"       dext	%1, %0, 8, 8\n"
1901 			"2:     sb	%1, 0(%2)\n"
1902 			"       andi	%1, %2, 0x7\n"
1903 			"       beq	$0, %1, 9f\n"
1904 			"       daddiu	%2, %2, -1\n"
1905 			"       dext	%1, %0, 16, 8\n"
1906 			"3:     sb	%1, 0(%2)\n"
1907 			"       andi	%1, %2, 0x7\n"
1908 			"       beq	$0, %1, 9f\n"
1909 			"       daddiu	%2, %2, -1\n"
1910 			"       dext	%1, %0, 24, 8\n"
1911 			"4:     sb	%1, 0(%2)\n"
1912 			"       andi	%1, %2, 0x7\n"
1913 			"       beq	$0, %1, 9f\n"
1914 			"       daddiu	%2, %2, -1\n"
1915 			"       dextu	%1, %0, 32, 8\n"
1916 			"5:     sb	%1, 0(%2)\n"
1917 			"       andi	%1, %2, 0x7\n"
1918 			"       beq	$0, %1, 9f\n"
1919 			"       daddiu	%2, %2, -1\n"
1920 			"       dextu	%1, %0, 40, 8\n"
1921 			"6:     sb	%1, 0(%2)\n"
1922 			"       andi	%1, %2, 0x7\n"
1923 			"       beq	$0, %1, 9f\n"
1924 			"       daddiu	%2, %2, -1\n"
1925 			"       dextu	%1, %0, 48, 8\n"
1926 			"7:     sb	%1, 0(%2)\n"
1927 			"       andi	%1, %2, 0x7\n"
1928 			"       beq	$0, %1, 9f\n"
1929 			"       daddiu	%2, %2, -1\n"
1930 			"       dextu	%1, %0, 56, 8\n"
1931 			"0:     sb	%1, 0(%2)\n"
1932 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1933 			"9:\n"
1934 			"       .insn\n"
1935 			"       .section        .fixup,\"ax\"\n"
1936 			"8:     li	%3,%4\n"
1937 			"       j	9b\n"
1938 			"       .previous\n"
1939 			"       .section        __ex_table,\"a\"\n"
1940 			"       .word	1b,8b\n"
1941 			"       .word	2b,8b\n"
1942 			"       .word	3b,8b\n"
1943 			"       .word	4b,8b\n"
1944 			"       .word	5b,8b\n"
1945 			"       .word	6b,8b\n"
1946 			"       .word	7b,8b\n"
1947 			"       .word	0b,8b\n"
1948 			"       .previous\n"
1949 			"       .set	pop\n"
1950 			: "+&r"(rt), "=&r"(rs),
1951 			  "+&r"(vaddr), "+&r"(err)
1952 			: "i"(SIGSEGV)
1953 			: "memory");
1954 
1955 		MIPS_R2_STATS(stores);
1956 
1957 		break;
1958 	case ll_op:
1959 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1960 		if (vaddr & 0x3) {
1961 			current->thread.cp0_baduaddr = vaddr;
1962 			err = SIGBUS;
1963 			break;
1964 		}
1965 		if (!access_ok(VERIFY_READ, vaddr, 4)) {
1966 			current->thread.cp0_baduaddr = vaddr;
1967 			err = SIGBUS;
1968 			break;
1969 		}
1970 
1971 		if (!cpu_has_rw_llb) {
1972 			/*
1973 			 * An LL/SC block can't be safely emulated without
1974 			 * a Config5/LLB availability. So it's probably time to
1975 			 * kill our process before things get any worse. This is
1976 			 * because Config5/LLB allows us to use ERETNC so that
1977 			 * the LLAddr/LLB bit is not cleared when we return from
1978 			 * an exception. MIPS R2 LL/SC instructions trap with an
1979 			 * RI exception so once we emulate them here, we return
1980 			 * back to userland with ERETNC. That preserves the
1981 			 * LLAddr/LLB so the subsequent SC instruction will
1982 			 * succeed preserving the atomic semantics of the LL/SC
1983 			 * block. Without that, there is no safe way to emulate
1984 			 * an LL/SC block in MIPSR2 userland.
1985 			 */
1986 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
1987 			err = SIGKILL;
1988 			break;
1989 		}
1990 
1991 		__asm__ __volatile__(
1992 			"1:\n"
1993 			"ll	%0, 0(%2)\n"
1994 			"2:\n"
1995 			".insn\n"
1996 			".section        .fixup,\"ax\"\n"
1997 			"3:\n"
1998 			"li	%1, %3\n"
1999 			"j	2b\n"
2000 			".previous\n"
2001 			".section        __ex_table,\"a\"\n"
2002 			".word  1b, 3b\n"
2003 			".previous\n"
2004 			: "=&r"(res), "+&r"(err)
2005 			: "r"(vaddr), "i"(SIGSEGV)
2006 			: "memory");
2007 
2008 		if (MIPSInst_RT(inst) && !err)
2009 			regs->regs[MIPSInst_RT(inst)] = res;
2010 		MIPS_R2_STATS(llsc);
2011 
2012 		break;
2013 
2014 	case sc_op:
2015 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
2016 		if (vaddr & 0x3) {
2017 			current->thread.cp0_baduaddr = vaddr;
2018 			err = SIGBUS;
2019 			break;
2020 		}
2021 		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
2022 			current->thread.cp0_baduaddr = vaddr;
2023 			err = SIGBUS;
2024 			break;
2025 		}
2026 
2027 		if (!cpu_has_rw_llb) {
2028 			/*
2029 			 * An LL/SC block can't be safely emulated without
2030 			 * a Config5/LLB availability. So it's probably time to
2031 			 * kill our process before things get any worse. This is
2032 			 * because Config5/LLB allows us to use ERETNC so that
2033 			 * the LLAddr/LLB bit is not cleared when we return from
2034 			 * an exception. MIPS R2 LL/SC instructions trap with an
2035 			 * RI exception so once we emulate them here, we return
2036 			 * back to userland with ERETNC. That preserves the
2037 			 * LLAddr/LLB so the subsequent SC instruction will
2038 			 * succeed preserving the atomic semantics of the LL/SC
2039 			 * block. Without that, there is no safe way to emulate
2040 			 * an LL/SC block in MIPSR2 userland.
2041 			 */
2042 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
2043 			err = SIGKILL;
2044 			break;
2045 		}
2046 
2047 		res = regs->regs[MIPSInst_RT(inst)];
2048 
2049 		__asm__ __volatile__(
2050 			"1:\n"
2051 			"sc	%0, 0(%2)\n"
2052 			"2:\n"
2053 			".insn\n"
2054 			".section        .fixup,\"ax\"\n"
2055 			"3:\n"
2056 			"li	%1, %3\n"
2057 			"j	2b\n"
2058 			".previous\n"
2059 			".section        __ex_table,\"a\"\n"
2060 			".word	1b, 3b\n"
2061 			".previous\n"
2062 			: "+&r"(res), "+&r"(err)
2063 			: "r"(vaddr), "i"(SIGSEGV));
2064 
2065 		if (MIPSInst_RT(inst) && !err)
2066 			regs->regs[MIPSInst_RT(inst)] = res;
2067 
2068 		MIPS_R2_STATS(llsc);
2069 
2070 		break;
2071 
2072 	case lld_op:
2073 		if (config_enabled(CONFIG_32BIT)) {
2074 		    err = SIGILL;
2075 		    break;
2076 		}
2077 
2078 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
2079 		if (vaddr & 0x7) {
2080 			current->thread.cp0_baduaddr = vaddr;
2081 			err = SIGBUS;
2082 			break;
2083 		}
2084 		if (!access_ok(VERIFY_READ, vaddr, 8)) {
2085 			current->thread.cp0_baduaddr = vaddr;
2086 			err = SIGBUS;
2087 			break;
2088 		}
2089 
2090 		if (!cpu_has_rw_llb) {
2091 			/*
2092 			 * An LL/SC block can't be safely emulated without
2093 			 * a Config5/LLB availability. So it's probably time to
2094 			 * kill our process before things get any worse. This is
2095 			 * because Config5/LLB allows us to use ERETNC so that
2096 			 * the LLAddr/LLB bit is not cleared when we return from
2097 			 * an exception. MIPS R2 LL/SC instructions trap with an
2098 			 * RI exception so once we emulate them here, we return
2099 			 * back to userland with ERETNC. That preserves the
2100 			 * LLAddr/LLB so the subsequent SC instruction will
2101 			 * succeed preserving the atomic semantics of the LL/SC
2102 			 * block. Without that, there is no safe way to emulate
2103 			 * an LL/SC block in MIPSR2 userland.
2104 			 */
2105 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
2106 			err = SIGKILL;
2107 			break;
2108 		}
2109 
2110 		__asm__ __volatile__(
2111 			"1:\n"
2112 			"lld	%0, 0(%2)\n"
2113 			"2:\n"
2114 			".insn\n"
2115 			".section        .fixup,\"ax\"\n"
2116 			"3:\n"
2117 			"li	%1, %3\n"
2118 			"j	2b\n"
2119 			".previous\n"
2120 			".section        __ex_table,\"a\"\n"
2121 			".word  1b, 3b\n"
2122 			".previous\n"
2123 			: "=&r"(res), "+&r"(err)
2124 			: "r"(vaddr), "i"(SIGSEGV)
2125 			: "memory");
2126 		if (MIPSInst_RT(inst) && !err)
2127 			regs->regs[MIPSInst_RT(inst)] = res;
2128 
2129 		MIPS_R2_STATS(llsc);
2130 
2131 		break;
2132 
2133 	case scd_op:
2134 		if (config_enabled(CONFIG_32BIT)) {
2135 		    err = SIGILL;
2136 		    break;
2137 		}
2138 
2139 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
2140 		if (vaddr & 0x7) {
2141 			current->thread.cp0_baduaddr = vaddr;
2142 			err = SIGBUS;
2143 			break;
2144 		}
2145 		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
2146 			current->thread.cp0_baduaddr = vaddr;
2147 			err = SIGBUS;
2148 			break;
2149 		}
2150 
2151 		if (!cpu_has_rw_llb) {
2152 			/*
2153 			 * An LL/SC block can't be safely emulated without
2154 			 * a Config5/LLB availability. So it's probably time to
2155 			 * kill our process before things get any worse. This is
2156 			 * because Config5/LLB allows us to use ERETNC so that
2157 			 * the LLAddr/LLB bit is not cleared when we return from
2158 			 * an exception. MIPS R2 LL/SC instructions trap with an
2159 			 * RI exception so once we emulate them here, we return
2160 			 * back to userland with ERETNC. That preserves the
2161 			 * LLAddr/LLB so the subsequent SC instruction will
2162 			 * succeed preserving the atomic semantics of the LL/SC
2163 			 * block. Without that, there is no safe way to emulate
2164 			 * an LL/SC block in MIPSR2 userland.
2165 			 */
2166 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
2167 			err = SIGKILL;
2168 			break;
2169 		}
2170 
2171 		res = regs->regs[MIPSInst_RT(inst)];
2172 
2173 		__asm__ __volatile__(
2174 			"1:\n"
2175 			"scd	%0, 0(%2)\n"
2176 			"2:\n"
2177 			".insn\n"
2178 			".section        .fixup,\"ax\"\n"
2179 			"3:\n"
2180 			"li	%1, %3\n"
2181 			"j	2b\n"
2182 			".previous\n"
2183 			".section        __ex_table,\"a\"\n"
2184 			".word	1b, 3b\n"
2185 			".previous\n"
2186 			: "+&r"(res), "+&r"(err)
2187 			: "r"(vaddr), "i"(SIGSEGV));
2188 
2189 		if (MIPSInst_RT(inst) && !err)
2190 			regs->regs[MIPSInst_RT(inst)] = res;
2191 
2192 		MIPS_R2_STATS(llsc);
2193 
2194 		break;
2195 	case pref_op:
2196 		/* skip it */
2197 		break;
2198 	default:
2199 		err = SIGILL;
2200 	}
2201 
2202 	/*
2203 	 * Lets not return to userland just yet. It's constly and
2204 	 * it's likely we have more R2 instructions to emulate
2205 	 */
2206 	if (!err && (pass++ < MIPS_R2_EMUL_TOTAL_PASS)) {
2207 		regs->cp0_cause &= ~CAUSEF_BD;
2208 		err = get_user(inst, (u32 __user *)regs->cp0_epc);
2209 		if (!err)
2210 			goto repeat;
2211 
2212 		if (err < 0)
2213 			err = SIGSEGV;
2214 	}
2215 
2216 	if (err && (err != SIGEMT)) {
2217 		regs->regs[31] = r31;
2218 		regs->cp0_epc = epc;
2219 	}
2220 
2221 	/* Likely a MIPS R6 compatible instruction */
2222 	if (pass && (err == SIGILL))
2223 		err = 0;
2224 
2225 	return err;
2226 }
2227 
2228 #ifdef CONFIG_DEBUG_FS
2229 
2230 static int mipsr2_stats_show(struct seq_file *s, void *unused)
2231 {
2232 
2233 	seq_printf(s, "Instruction\tTotal\tBDslot\n------------------------------\n");
2234 	seq_printf(s, "movs\t\t%ld\t%ld\n",
2235 		   (unsigned long)__this_cpu_read(mipsr2emustats.movs),
2236 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.movs));
2237 	seq_printf(s, "hilo\t\t%ld\t%ld\n",
2238 		   (unsigned long)__this_cpu_read(mipsr2emustats.hilo),
2239 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.hilo));
2240 	seq_printf(s, "muls\t\t%ld\t%ld\n",
2241 		   (unsigned long)__this_cpu_read(mipsr2emustats.muls),
2242 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.muls));
2243 	seq_printf(s, "divs\t\t%ld\t%ld\n",
2244 		   (unsigned long)__this_cpu_read(mipsr2emustats.divs),
2245 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.divs));
2246 	seq_printf(s, "dsps\t\t%ld\t%ld\n",
2247 		   (unsigned long)__this_cpu_read(mipsr2emustats.dsps),
2248 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.dsps));
2249 	seq_printf(s, "bops\t\t%ld\t%ld\n",
2250 		   (unsigned long)__this_cpu_read(mipsr2emustats.bops),
2251 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.bops));
2252 	seq_printf(s, "traps\t\t%ld\t%ld\n",
2253 		   (unsigned long)__this_cpu_read(mipsr2emustats.traps),
2254 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.traps));
2255 	seq_printf(s, "fpus\t\t%ld\t%ld\n",
2256 		   (unsigned long)__this_cpu_read(mipsr2emustats.fpus),
2257 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.fpus));
2258 	seq_printf(s, "loads\t\t%ld\t%ld\n",
2259 		   (unsigned long)__this_cpu_read(mipsr2emustats.loads),
2260 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.loads));
2261 	seq_printf(s, "stores\t\t%ld\t%ld\n",
2262 		   (unsigned long)__this_cpu_read(mipsr2emustats.stores),
2263 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.stores));
2264 	seq_printf(s, "llsc\t\t%ld\t%ld\n",
2265 		   (unsigned long)__this_cpu_read(mipsr2emustats.llsc),
2266 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.llsc));
2267 	seq_printf(s, "dsemul\t\t%ld\t%ld\n",
2268 		   (unsigned long)__this_cpu_read(mipsr2emustats.dsemul),
2269 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.dsemul));
2270 	seq_printf(s, "jr\t\t%ld\n",
2271 		   (unsigned long)__this_cpu_read(mipsr2bremustats.jrs));
2272 	seq_printf(s, "bltzl\t\t%ld\n",
2273 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bltzl));
2274 	seq_printf(s, "bgezl\t\t%ld\n",
2275 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgezl));
2276 	seq_printf(s, "bltzll\t\t%ld\n",
2277 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bltzll));
2278 	seq_printf(s, "bgezll\t\t%ld\n",
2279 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgezll));
2280 	seq_printf(s, "bltzal\t\t%ld\n",
2281 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bltzal));
2282 	seq_printf(s, "bgezal\t\t%ld\n",
2283 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgezal));
2284 	seq_printf(s, "beql\t\t%ld\n",
2285 		   (unsigned long)__this_cpu_read(mipsr2bremustats.beql));
2286 	seq_printf(s, "bnel\t\t%ld\n",
2287 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bnel));
2288 	seq_printf(s, "blezl\t\t%ld\n",
2289 		   (unsigned long)__this_cpu_read(mipsr2bremustats.blezl));
2290 	seq_printf(s, "bgtzl\t\t%ld\n",
2291 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgtzl));
2292 
2293 	return 0;
2294 }
2295 
2296 static int mipsr2_stats_clear_show(struct seq_file *s, void *unused)
2297 {
2298 	mipsr2_stats_show(s, unused);
2299 
2300 	__this_cpu_write((mipsr2emustats).movs, 0);
2301 	__this_cpu_write((mipsr2bdemustats).movs, 0);
2302 	__this_cpu_write((mipsr2emustats).hilo, 0);
2303 	__this_cpu_write((mipsr2bdemustats).hilo, 0);
2304 	__this_cpu_write((mipsr2emustats).muls, 0);
2305 	__this_cpu_write((mipsr2bdemustats).muls, 0);
2306 	__this_cpu_write((mipsr2emustats).divs, 0);
2307 	__this_cpu_write((mipsr2bdemustats).divs, 0);
2308 	__this_cpu_write((mipsr2emustats).dsps, 0);
2309 	__this_cpu_write((mipsr2bdemustats).dsps, 0);
2310 	__this_cpu_write((mipsr2emustats).bops, 0);
2311 	__this_cpu_write((mipsr2bdemustats).bops, 0);
2312 	__this_cpu_write((mipsr2emustats).traps, 0);
2313 	__this_cpu_write((mipsr2bdemustats).traps, 0);
2314 	__this_cpu_write((mipsr2emustats).fpus, 0);
2315 	__this_cpu_write((mipsr2bdemustats).fpus, 0);
2316 	__this_cpu_write((mipsr2emustats).loads, 0);
2317 	__this_cpu_write((mipsr2bdemustats).loads, 0);
2318 	__this_cpu_write((mipsr2emustats).stores, 0);
2319 	__this_cpu_write((mipsr2bdemustats).stores, 0);
2320 	__this_cpu_write((mipsr2emustats).llsc, 0);
2321 	__this_cpu_write((mipsr2bdemustats).llsc, 0);
2322 	__this_cpu_write((mipsr2emustats).dsemul, 0);
2323 	__this_cpu_write((mipsr2bdemustats).dsemul, 0);
2324 	__this_cpu_write((mipsr2bremustats).jrs, 0);
2325 	__this_cpu_write((mipsr2bremustats).bltzl, 0);
2326 	__this_cpu_write((mipsr2bremustats).bgezl, 0);
2327 	__this_cpu_write((mipsr2bremustats).bltzll, 0);
2328 	__this_cpu_write((mipsr2bremustats).bgezll, 0);
2329 	__this_cpu_write((mipsr2bremustats).bltzal, 0);
2330 	__this_cpu_write((mipsr2bremustats).bgezal, 0);
2331 	__this_cpu_write((mipsr2bremustats).beql, 0);
2332 	__this_cpu_write((mipsr2bremustats).bnel, 0);
2333 	__this_cpu_write((mipsr2bremustats).blezl, 0);
2334 	__this_cpu_write((mipsr2bremustats).bgtzl, 0);
2335 
2336 	return 0;
2337 }
2338 
2339 static int mipsr2_stats_open(struct inode *inode, struct file *file)
2340 {
2341 	return single_open(file, mipsr2_stats_show, inode->i_private);
2342 }
2343 
2344 static int mipsr2_stats_clear_open(struct inode *inode, struct file *file)
2345 {
2346 	return single_open(file, mipsr2_stats_clear_show, inode->i_private);
2347 }
2348 
2349 static const struct file_operations mipsr2_emul_fops = {
2350 	.open                   = mipsr2_stats_open,
2351 	.read			= seq_read,
2352 	.llseek			= seq_lseek,
2353 	.release		= single_release,
2354 };
2355 
2356 static const struct file_operations mipsr2_clear_fops = {
2357 	.open                   = mipsr2_stats_clear_open,
2358 	.read			= seq_read,
2359 	.llseek			= seq_lseek,
2360 	.release		= single_release,
2361 };
2362 
2363 
2364 static int __init mipsr2_init_debugfs(void)
2365 {
2366 	extern struct dentry	*mips_debugfs_dir;
2367 	struct dentry		*mipsr2_emul;
2368 
2369 	if (!mips_debugfs_dir)
2370 		return -ENODEV;
2371 
2372 	mipsr2_emul = debugfs_create_file("r2_emul_stats", S_IRUGO,
2373 					  mips_debugfs_dir, NULL,
2374 					  &mipsr2_emul_fops);
2375 	if (!mipsr2_emul)
2376 		return -ENOMEM;
2377 
2378 	mipsr2_emul = debugfs_create_file("r2_emul_stats_clear", S_IRUGO,
2379 					  mips_debugfs_dir, NULL,
2380 					  &mipsr2_clear_fops);
2381 	if (!mipsr2_emul)
2382 		return -ENOMEM;
2383 
2384 	return 0;
2385 }
2386 
2387 device_initcall(mipsr2_init_debugfs);
2388 
2389 #endif /* CONFIG_DEBUG_FS */
2390