xref: /linux/arch/mips/kernel/mips-r2-to-r6-emul.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
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  * movt_func - Emulate a MOVT 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 	if (((csr & cond) == 0) && MIPSInst_RD(ir))
204 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
205 	MIPS_R2_STATS(movs);
206 	return 0;
207 }
208 
209 /**
210  * movt_func - Emulate a MOVT instruction
211  * @regs: Process register set
212  * @ir: Instruction
213  *
214  * Returns 0 since it always succeeds.
215  */
216 static int movt_func(struct pt_regs *regs, u32 ir)
217 {
218 	u32 csr;
219 	u32 cond;
220 
221 	csr = current->thread.fpu.fcr31;
222 	cond = fpucondbit[MIPSInst_RT(ir) >> 2];
223 
224 	if (((csr & cond) != 0) && MIPSInst_RD(ir))
225 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
226 
227 	MIPS_R2_STATS(movs);
228 
229 	return 0;
230 }
231 
232 /**
233  * jr_func - Emulate a JR instruction.
234  * @pt_regs: Process register set
235  * @ir: Instruction
236  *
237  * Returns SIGILL if JR was in delay slot, SIGEMT if we
238  * can't compute the EPC, SIGSEGV if we can't access the
239  * userland instruction or 0 on success.
240  */
241 static int jr_func(struct pt_regs *regs, u32 ir)
242 {
243 	int err;
244 	unsigned long cepc, epc, nepc;
245 	u32 nir;
246 
247 	if (delay_slot(regs))
248 		return SIGILL;
249 
250 	/* EPC after the RI/JR instruction */
251 	nepc = regs->cp0_epc;
252 	/* Roll back to the reserved R2 JR instruction */
253 	regs->cp0_epc -= 4;
254 	epc = regs->cp0_epc;
255 	err = __compute_return_epc(regs);
256 
257 	if (err < 0)
258 		return SIGEMT;
259 
260 
261 	/* Computed EPC */
262 	cepc = regs->cp0_epc;
263 
264 	/* Get DS instruction */
265 	err = __get_user(nir, (u32 __user *)nepc);
266 	if (err)
267 		return SIGSEGV;
268 
269 	MIPS_R2BR_STATS(jrs);
270 
271 	/* If nir == 0(NOP), then nothing else to do */
272 	if (nir) {
273 		/*
274 		 * Negative err means FPU instruction in BD-slot,
275 		 * Zero err means 'BD-slot emulation done'
276 		 * For anything else we go back to trampoline emulation.
277 		 */
278 		err = mipsr6_emul(regs, nir);
279 		if (err > 0) {
280 			regs->cp0_epc = nepc;
281 			err = mips_dsemul(regs, nir, cepc);
282 			if (err == SIGILL)
283 				err = SIGEMT;
284 			MIPS_R2_STATS(dsemul);
285 		}
286 	}
287 
288 	return err;
289 }
290 
291 /**
292  * movz_func - Emulate a MOVZ instruction
293  * @regs: Process register set
294  * @ir: Instruction
295  *
296  * Returns 0 since it always succeeds.
297  */
298 static int movz_func(struct pt_regs *regs, u32 ir)
299 {
300 	if (((regs->regs[MIPSInst_RT(ir)]) == 0) && MIPSInst_RD(ir))
301 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
302 	MIPS_R2_STATS(movs);
303 
304 	return 0;
305 }
306 
307 /**
308  * movn_func - Emulate a MOVZ instruction
309  * @regs: Process register set
310  * @ir: Instruction
311  *
312  * Returns 0 since it always succeeds.
313  */
314 static int movn_func(struct pt_regs *regs, u32 ir)
315 {
316 	if (((regs->regs[MIPSInst_RT(ir)]) != 0) && MIPSInst_RD(ir))
317 		regs->regs[MIPSInst_RD(ir)] = regs->regs[MIPSInst_RS(ir)];
318 	MIPS_R2_STATS(movs);
319 
320 	return 0;
321 }
322 
323 /**
324  * mfhi_func - Emulate a MFHI instruction
325  * @regs: Process register set
326  * @ir: Instruction
327  *
328  * Returns 0 since it always succeeds.
329  */
330 static int mfhi_func(struct pt_regs *regs, u32 ir)
331 {
332 	if (MIPSInst_RD(ir))
333 		regs->regs[MIPSInst_RD(ir)] = regs->hi;
334 
335 	MIPS_R2_STATS(hilo);
336 
337 	return 0;
338 }
339 
340 /**
341  * mthi_func - Emulate a MTHI instruction
342  * @regs: Process register set
343  * @ir: Instruction
344  *
345  * Returns 0 since it always succeeds.
346  */
347 static int mthi_func(struct pt_regs *regs, u32 ir)
348 {
349 	regs->hi = regs->regs[MIPSInst_RS(ir)];
350 
351 	MIPS_R2_STATS(hilo);
352 
353 	return 0;
354 }
355 
356 /**
357  * mflo_func - Emulate a MFLO instruction
358  * @regs: Process register set
359  * @ir: Instruction
360  *
361  * Returns 0 since it always succeeds.
362  */
363 static int mflo_func(struct pt_regs *regs, u32 ir)
364 {
365 	if (MIPSInst_RD(ir))
366 		regs->regs[MIPSInst_RD(ir)] = regs->lo;
367 
368 	MIPS_R2_STATS(hilo);
369 
370 	return 0;
371 }
372 
373 /**
374  * mtlo_func - Emulate a MTLO instruction
375  * @regs: Process register set
376  * @ir: Instruction
377  *
378  * Returns 0 since it always succeeds.
379  */
380 static int mtlo_func(struct pt_regs *regs, u32 ir)
381 {
382 	regs->lo = regs->regs[MIPSInst_RS(ir)];
383 
384 	MIPS_R2_STATS(hilo);
385 
386 	return 0;
387 }
388 
389 /**
390  * mult_func - Emulate a MULT instruction
391  * @regs: Process register set
392  * @ir: Instruction
393  *
394  * Returns 0 since it always succeeds.
395  */
396 static int mult_func(struct pt_regs *regs, u32 ir)
397 {
398 	s64 res;
399 	s32 rt, rs;
400 
401 	rt = regs->regs[MIPSInst_RT(ir)];
402 	rs = regs->regs[MIPSInst_RS(ir)];
403 	res = (s64)rt * (s64)rs;
404 
405 	rs = res;
406 	regs->lo = (s64)rs;
407 	rt = res >> 32;
408 	res = (s64)rt;
409 	regs->hi = res;
410 
411 	MIPS_R2_STATS(muls);
412 
413 	return 0;
414 }
415 
416 /**
417  * multu_func - Emulate a MULTU instruction
418  * @regs: Process register set
419  * @ir: Instruction
420  *
421  * Returns 0 since it always succeeds.
422  */
423 static int multu_func(struct pt_regs *regs, u32 ir)
424 {
425 	u64 res;
426 	u32 rt, rs;
427 
428 	rt = regs->regs[MIPSInst_RT(ir)];
429 	rs = regs->regs[MIPSInst_RS(ir)];
430 	res = (u64)rt * (u64)rs;
431 	rt = res;
432 	regs->lo = (s64)rt;
433 	regs->hi = (s64)(res >> 32);
434 
435 	MIPS_R2_STATS(muls);
436 
437 	return 0;
438 }
439 
440 /**
441  * div_func - Emulate a DIV instruction
442  * @regs: Process register set
443  * @ir: Instruction
444  *
445  * Returns 0 since it always succeeds.
446  */
447 static int div_func(struct pt_regs *regs, u32 ir)
448 {
449 	s32 rt, rs;
450 
451 	rt = regs->regs[MIPSInst_RT(ir)];
452 	rs = regs->regs[MIPSInst_RS(ir)];
453 
454 	regs->lo = (s64)(rs / rt);
455 	regs->hi = (s64)(rs % rt);
456 
457 	MIPS_R2_STATS(divs);
458 
459 	return 0;
460 }
461 
462 /**
463  * divu_func - Emulate a DIVU instruction
464  * @regs: Process register set
465  * @ir: Instruction
466  *
467  * Returns 0 since it always succeeds.
468  */
469 static int divu_func(struct pt_regs *regs, u32 ir)
470 {
471 	u32 rt, rs;
472 
473 	rt = regs->regs[MIPSInst_RT(ir)];
474 	rs = regs->regs[MIPSInst_RS(ir)];
475 
476 	regs->lo = (s64)(rs / rt);
477 	regs->hi = (s64)(rs % rt);
478 
479 	MIPS_R2_STATS(divs);
480 
481 	return 0;
482 }
483 
484 /**
485  * dmult_func - Emulate a DMULT instruction
486  * @regs: Process register set
487  * @ir: Instruction
488  *
489  * Returns 0 on success or SIGILL for 32-bit kernels.
490  */
491 static int dmult_func(struct pt_regs *regs, u32 ir)
492 {
493 	s64 res;
494 	s64 rt, rs;
495 
496 	if (config_enabled(CONFIG_32BIT))
497 		return SIGILL;
498 
499 	rt = regs->regs[MIPSInst_RT(ir)];
500 	rs = regs->regs[MIPSInst_RS(ir)];
501 	res = rt * rs;
502 
503 	regs->lo = res;
504 	__asm__ __volatile__(
505 		"dmuh %0, %1, %2\t\n"
506 		: "=r"(res)
507 		: "r"(rt), "r"(rs));
508 
509 	regs->hi = res;
510 
511 	MIPS_R2_STATS(muls);
512 
513 	return 0;
514 }
515 
516 /**
517  * dmultu_func - Emulate a DMULTU instruction
518  * @regs: Process register set
519  * @ir: Instruction
520  *
521  * Returns 0 on success or SIGILL for 32-bit kernels.
522  */
523 static int dmultu_func(struct pt_regs *regs, u32 ir)
524 {
525 	u64 res;
526 	u64 rt, rs;
527 
528 	if (config_enabled(CONFIG_32BIT))
529 		return SIGILL;
530 
531 	rt = regs->regs[MIPSInst_RT(ir)];
532 	rs = regs->regs[MIPSInst_RS(ir)];
533 	res = rt * rs;
534 
535 	regs->lo = res;
536 	__asm__ __volatile__(
537 		"dmuhu %0, %1, %2\t\n"
538 		: "=r"(res)
539 		: "r"(rt), "r"(rs));
540 
541 	regs->hi = res;
542 
543 	MIPS_R2_STATS(muls);
544 
545 	return 0;
546 }
547 
548 /**
549  * ddiv_func - Emulate a DDIV instruction
550  * @regs: Process register set
551  * @ir: Instruction
552  *
553  * Returns 0 on success or SIGILL for 32-bit kernels.
554  */
555 static int ddiv_func(struct pt_regs *regs, u32 ir)
556 {
557 	s64 rt, rs;
558 
559 	if (config_enabled(CONFIG_32BIT))
560 		return SIGILL;
561 
562 	rt = regs->regs[MIPSInst_RT(ir)];
563 	rs = regs->regs[MIPSInst_RS(ir)];
564 
565 	regs->lo = rs / rt;
566 	regs->hi = rs % rt;
567 
568 	MIPS_R2_STATS(divs);
569 
570 	return 0;
571 }
572 
573 /**
574  * ddivu_func - Emulate a DDIVU instruction
575  * @regs: Process register set
576  * @ir: Instruction
577  *
578  * Returns 0 on success or SIGILL for 32-bit kernels.
579  */
580 static int ddivu_func(struct pt_regs *regs, u32 ir)
581 {
582 	u64 rt, rs;
583 
584 	if (config_enabled(CONFIG_32BIT))
585 		return SIGILL;
586 
587 	rt = regs->regs[MIPSInst_RT(ir)];
588 	rs = regs->regs[MIPSInst_RS(ir)];
589 
590 	regs->lo = rs / rt;
591 	regs->hi = rs % rt;
592 
593 	MIPS_R2_STATS(divs);
594 
595 	return 0;
596 }
597 
598 /* R6 removed instructions for the SPECIAL opcode */
599 static struct r2_decoder_table spec_op_table[] = {
600 	{ 0xfc1ff83f, 0x00000008, jr_func },
601 	{ 0xfc00ffff, 0x00000018, mult_func },
602 	{ 0xfc00ffff, 0x00000019, multu_func },
603 	{ 0xfc00ffff, 0x0000001c, dmult_func },
604 	{ 0xfc00ffff, 0x0000001d, dmultu_func },
605 	{ 0xffff07ff, 0x00000010, mfhi_func },
606 	{ 0xfc1fffff, 0x00000011, mthi_func },
607 	{ 0xffff07ff, 0x00000012, mflo_func },
608 	{ 0xfc1fffff, 0x00000013, mtlo_func },
609 	{ 0xfc0307ff, 0x00000001, movf_func },
610 	{ 0xfc0307ff, 0x00010001, movt_func },
611 	{ 0xfc0007ff, 0x0000000a, movz_func },
612 	{ 0xfc0007ff, 0x0000000b, movn_func },
613 	{ 0xfc00ffff, 0x0000001a, div_func },
614 	{ 0xfc00ffff, 0x0000001b, divu_func },
615 	{ 0xfc00ffff, 0x0000001e, ddiv_func },
616 	{ 0xfc00ffff, 0x0000001f, ddivu_func },
617 	{}
618 };
619 
620 /**
621  * madd_func - Emulate a MADD instruction
622  * @regs: Process register set
623  * @ir: Instruction
624  *
625  * Returns 0 since it always succeeds.
626  */
627 static int madd_func(struct pt_regs *regs, u32 ir)
628 {
629 	s64 res;
630 	s32 rt, rs;
631 
632 	rt = regs->regs[MIPSInst_RT(ir)];
633 	rs = regs->regs[MIPSInst_RS(ir)];
634 	res = (s64)rt * (s64)rs;
635 	rt = regs->hi;
636 	rs = regs->lo;
637 	res += ((((s64)rt) << 32) | (u32)rs);
638 
639 	rt = res;
640 	regs->lo = (s64)rt;
641 	rs = res >> 32;
642 	regs->hi = (s64)rs;
643 
644 	MIPS_R2_STATS(dsps);
645 
646 	return 0;
647 }
648 
649 /**
650  * maddu_func - Emulate a MADDU instruction
651  * @regs: Process register set
652  * @ir: Instruction
653  *
654  * Returns 0 since it always succeeds.
655  */
656 static int maddu_func(struct pt_regs *regs, u32 ir)
657 {
658 	u64 res;
659 	u32 rt, rs;
660 
661 	rt = regs->regs[MIPSInst_RT(ir)];
662 	rs = regs->regs[MIPSInst_RS(ir)];
663 	res = (u64)rt * (u64)rs;
664 	rt = regs->hi;
665 	rs = regs->lo;
666 	res += ((((s64)rt) << 32) | (u32)rs);
667 
668 	rt = res;
669 	regs->lo = (s64)rt;
670 	rs = res >> 32;
671 	regs->hi = (s64)rs;
672 
673 	MIPS_R2_STATS(dsps);
674 
675 	return 0;
676 }
677 
678 /**
679  * msub_func - Emulate a MSUB instruction
680  * @regs: Process register set
681  * @ir: Instruction
682  *
683  * Returns 0 since it always succeeds.
684  */
685 static int msub_func(struct pt_regs *regs, u32 ir)
686 {
687 	s64 res;
688 	s32 rt, rs;
689 
690 	rt = regs->regs[MIPSInst_RT(ir)];
691 	rs = regs->regs[MIPSInst_RS(ir)];
692 	res = (s64)rt * (s64)rs;
693 	rt = regs->hi;
694 	rs = regs->lo;
695 	res = ((((s64)rt) << 32) | (u32)rs) - res;
696 
697 	rt = res;
698 	regs->lo = (s64)rt;
699 	rs = res >> 32;
700 	regs->hi = (s64)rs;
701 
702 	MIPS_R2_STATS(dsps);
703 
704 	return 0;
705 }
706 
707 /**
708  * msubu_func - Emulate a MSUBU instruction
709  * @regs: Process register set
710  * @ir: Instruction
711  *
712  * Returns 0 since it always succeeds.
713  */
714 static int msubu_func(struct pt_regs *regs, u32 ir)
715 {
716 	u64 res;
717 	u32 rt, rs;
718 
719 	rt = regs->regs[MIPSInst_RT(ir)];
720 	rs = regs->regs[MIPSInst_RS(ir)];
721 	res = (u64)rt * (u64)rs;
722 	rt = regs->hi;
723 	rs = regs->lo;
724 	res = ((((s64)rt) << 32) | (u32)rs) - res;
725 
726 	rt = res;
727 	regs->lo = (s64)rt;
728 	rs = res >> 32;
729 	regs->hi = (s64)rs;
730 
731 	MIPS_R2_STATS(dsps);
732 
733 	return 0;
734 }
735 
736 /**
737  * mul_func - Emulate a MUL instruction
738  * @regs: Process register set
739  * @ir: Instruction
740  *
741  * Returns 0 since it always succeeds.
742  */
743 static int mul_func(struct pt_regs *regs, u32 ir)
744 {
745 	s64 res;
746 	s32 rt, rs;
747 
748 	if (!MIPSInst_RD(ir))
749 		return 0;
750 	rt = regs->regs[MIPSInst_RT(ir)];
751 	rs = regs->regs[MIPSInst_RS(ir)];
752 	res = (s64)rt * (s64)rs;
753 
754 	rs = res;
755 	regs->regs[MIPSInst_RD(ir)] = (s64)rs;
756 
757 	MIPS_R2_STATS(muls);
758 
759 	return 0;
760 }
761 
762 /**
763  * clz_func - Emulate a CLZ instruction
764  * @regs: Process register set
765  * @ir: Instruction
766  *
767  * Returns 0 since it always succeeds.
768  */
769 static int clz_func(struct pt_regs *regs, u32 ir)
770 {
771 	u32 res;
772 	u32 rs;
773 
774 	if (!MIPSInst_RD(ir))
775 		return 0;
776 
777 	rs = regs->regs[MIPSInst_RS(ir)];
778 	__asm__ __volatile__("clz %0, %1" : "=r"(res) : "r"(rs));
779 	regs->regs[MIPSInst_RD(ir)] = res;
780 
781 	MIPS_R2_STATS(bops);
782 
783 	return 0;
784 }
785 
786 /**
787  * clo_func - Emulate a CLO instruction
788  * @regs: Process register set
789  * @ir: Instruction
790  *
791  * Returns 0 since it always succeeds.
792  */
793 
794 static int clo_func(struct pt_regs *regs, u32 ir)
795 {
796 	u32 res;
797 	u32 rs;
798 
799 	if (!MIPSInst_RD(ir))
800 		return 0;
801 
802 	rs = regs->regs[MIPSInst_RS(ir)];
803 	__asm__ __volatile__("clo %0, %1" : "=r"(res) : "r"(rs));
804 	regs->regs[MIPSInst_RD(ir)] = res;
805 
806 	MIPS_R2_STATS(bops);
807 
808 	return 0;
809 }
810 
811 /**
812  * dclz_func - Emulate a DCLZ instruction
813  * @regs: Process register set
814  * @ir: Instruction
815  *
816  * Returns 0 since it always succeeds.
817  */
818 static int dclz_func(struct pt_regs *regs, u32 ir)
819 {
820 	u64 res;
821 	u64 rs;
822 
823 	if (config_enabled(CONFIG_32BIT))
824 		return SIGILL;
825 
826 	if (!MIPSInst_RD(ir))
827 		return 0;
828 
829 	rs = regs->regs[MIPSInst_RS(ir)];
830 	__asm__ __volatile__("dclz %0, %1" : "=r"(res) : "r"(rs));
831 	regs->regs[MIPSInst_RD(ir)] = res;
832 
833 	MIPS_R2_STATS(bops);
834 
835 	return 0;
836 }
837 
838 /**
839  * dclo_func - Emulate a DCLO instruction
840  * @regs: Process register set
841  * @ir: Instruction
842  *
843  * Returns 0 since it always succeeds.
844  */
845 static int dclo_func(struct pt_regs *regs, u32 ir)
846 {
847 	u64 res;
848 	u64 rs;
849 
850 	if (config_enabled(CONFIG_32BIT))
851 		return SIGILL;
852 
853 	if (!MIPSInst_RD(ir))
854 		return 0;
855 
856 	rs = regs->regs[MIPSInst_RS(ir)];
857 	__asm__ __volatile__("dclo %0, %1" : "=r"(res) : "r"(rs));
858 	regs->regs[MIPSInst_RD(ir)] = res;
859 
860 	MIPS_R2_STATS(bops);
861 
862 	return 0;
863 }
864 
865 /* R6 removed instructions for the SPECIAL2 opcode */
866 static struct r2_decoder_table spec2_op_table[] = {
867 	{ 0xfc00ffff, 0x70000000, madd_func },
868 	{ 0xfc00ffff, 0x70000001, maddu_func },
869 	{ 0xfc0007ff, 0x70000002, mul_func },
870 	{ 0xfc00ffff, 0x70000004, msub_func },
871 	{ 0xfc00ffff, 0x70000005, msubu_func },
872 	{ 0xfc0007ff, 0x70000020, clz_func },
873 	{ 0xfc0007ff, 0x70000021, clo_func },
874 	{ 0xfc0007ff, 0x70000024, dclz_func },
875 	{ 0xfc0007ff, 0x70000025, dclo_func },
876 	{ }
877 };
878 
879 static inline int mipsr2_find_op_func(struct pt_regs *regs, u32 inst,
880 				      struct r2_decoder_table *table)
881 {
882 	struct r2_decoder_table *p;
883 	int err;
884 
885 	for (p = table; p->func; p++) {
886 		if ((inst & p->mask) == p->code) {
887 			err = (p->func)(regs, inst);
888 			return err;
889 		}
890 	}
891 	return SIGILL;
892 }
893 
894 /**
895  * mipsr2_decoder: Decode and emulate a MIPS R2 instruction
896  * @regs: Process register set
897  * @inst: Instruction to decode and emulate
898  */
899 int mipsr2_decoder(struct pt_regs *regs, u32 inst)
900 {
901 	int err = 0;
902 	unsigned long vaddr;
903 	u32 nir;
904 	unsigned long cpc, epc, nepc, r31, res, rs, rt;
905 
906 	void __user *fault_addr = NULL;
907 	int pass = 0;
908 
909 repeat:
910 	r31 = regs->regs[31];
911 	epc = regs->cp0_epc;
912 	err = compute_return_epc(regs);
913 	if (err < 0) {
914 		BUG();
915 		return SIGEMT;
916 	}
917 	pr_debug("Emulating the 0x%08x R2 instruction @ 0x%08lx (pass=%d))\n",
918 		 inst, epc, pass);
919 
920 	switch (MIPSInst_OPCODE(inst)) {
921 	case spec_op:
922 		err = mipsr2_find_op_func(regs, inst, spec_op_table);
923 		if (err < 0) {
924 			/* FPU instruction under JR */
925 			regs->cp0_cause |= CAUSEF_BD;
926 			goto fpu_emul;
927 		}
928 		break;
929 	case spec2_op:
930 		err = mipsr2_find_op_func(regs, inst, spec2_op_table);
931 		break;
932 	case bcond_op:
933 		rt = MIPSInst_RT(inst);
934 		rs = MIPSInst_RS(inst);
935 		switch (rt) {
936 		case tgei_op:
937 			if ((long)regs->regs[rs] >= MIPSInst_SIMM(inst))
938 				do_trap_or_bp(regs, 0, "TGEI");
939 
940 			MIPS_R2_STATS(traps);
941 
942 			break;
943 		case tgeiu_op:
944 			if (regs->regs[rs] >= MIPSInst_UIMM(inst))
945 				do_trap_or_bp(regs, 0, "TGEIU");
946 
947 			MIPS_R2_STATS(traps);
948 
949 			break;
950 		case tlti_op:
951 			if ((long)regs->regs[rs] < MIPSInst_SIMM(inst))
952 				do_trap_or_bp(regs, 0, "TLTI");
953 
954 			MIPS_R2_STATS(traps);
955 
956 			break;
957 		case tltiu_op:
958 			if (regs->regs[rs] < MIPSInst_UIMM(inst))
959 				do_trap_or_bp(regs, 0, "TLTIU");
960 
961 			MIPS_R2_STATS(traps);
962 
963 			break;
964 		case teqi_op:
965 			if (regs->regs[rs] == MIPSInst_SIMM(inst))
966 				do_trap_or_bp(regs, 0, "TEQI");
967 
968 			MIPS_R2_STATS(traps);
969 
970 			break;
971 		case tnei_op:
972 			if (regs->regs[rs] != MIPSInst_SIMM(inst))
973 				do_trap_or_bp(regs, 0, "TNEI");
974 
975 			MIPS_R2_STATS(traps);
976 
977 			break;
978 		case bltzl_op:
979 		case bgezl_op:
980 		case bltzall_op:
981 		case bgezall_op:
982 			if (delay_slot(regs)) {
983 				err = SIGILL;
984 				break;
985 			}
986 			regs->regs[31] = r31;
987 			regs->cp0_epc = epc;
988 			err = __compute_return_epc(regs);
989 			if (err < 0)
990 				return SIGEMT;
991 			if (err != BRANCH_LIKELY_TAKEN)
992 				break;
993 			cpc = regs->cp0_epc;
994 			nepc = epc + 4;
995 			err = __get_user(nir, (u32 __user *)nepc);
996 			if (err) {
997 				err = SIGSEGV;
998 				break;
999 			}
1000 			/*
1001 			 * This will probably be optimized away when
1002 			 * CONFIG_DEBUG_FS is not enabled
1003 			 */
1004 			switch (rt) {
1005 			case bltzl_op:
1006 				MIPS_R2BR_STATS(bltzl);
1007 				break;
1008 			case bgezl_op:
1009 				MIPS_R2BR_STATS(bgezl);
1010 				break;
1011 			case bltzall_op:
1012 				MIPS_R2BR_STATS(bltzall);
1013 				break;
1014 			case bgezall_op:
1015 				MIPS_R2BR_STATS(bgezall);
1016 				break;
1017 			}
1018 
1019 			switch (MIPSInst_OPCODE(nir)) {
1020 			case cop1_op:
1021 			case cop1x_op:
1022 			case lwc1_op:
1023 			case swc1_op:
1024 				regs->cp0_cause |= CAUSEF_BD;
1025 				goto fpu_emul;
1026 			}
1027 			if (nir) {
1028 				err = mipsr6_emul(regs, nir);
1029 				if (err > 0) {
1030 					err = mips_dsemul(regs, nir, cpc);
1031 					if (err == SIGILL)
1032 						err = SIGEMT;
1033 					MIPS_R2_STATS(dsemul);
1034 				}
1035 			}
1036 			break;
1037 		case bltzal_op:
1038 		case bgezal_op:
1039 			if (delay_slot(regs)) {
1040 				err = SIGILL;
1041 				break;
1042 			}
1043 			regs->regs[31] = r31;
1044 			regs->cp0_epc = epc;
1045 			err = __compute_return_epc(regs);
1046 			if (err < 0)
1047 				return SIGEMT;
1048 			cpc = regs->cp0_epc;
1049 			nepc = epc + 4;
1050 			err = __get_user(nir, (u32 __user *)nepc);
1051 			if (err) {
1052 				err = SIGSEGV;
1053 				break;
1054 			}
1055 			/*
1056 			 * This will probably be optimized away when
1057 			 * CONFIG_DEBUG_FS is not enabled
1058 			 */
1059 			switch (rt) {
1060 			case bltzal_op:
1061 				MIPS_R2BR_STATS(bltzal);
1062 				break;
1063 			case bgezal_op:
1064 				MIPS_R2BR_STATS(bgezal);
1065 				break;
1066 			}
1067 
1068 			switch (MIPSInst_OPCODE(nir)) {
1069 			case cop1_op:
1070 			case cop1x_op:
1071 			case lwc1_op:
1072 			case swc1_op:
1073 				regs->cp0_cause |= CAUSEF_BD;
1074 				goto fpu_emul;
1075 			}
1076 			if (nir) {
1077 				err = mipsr6_emul(regs, nir);
1078 				if (err > 0) {
1079 					err = mips_dsemul(regs, nir, cpc);
1080 					if (err == SIGILL)
1081 						err = SIGEMT;
1082 					MIPS_R2_STATS(dsemul);
1083 				}
1084 			}
1085 			break;
1086 		default:
1087 			regs->regs[31] = r31;
1088 			regs->cp0_epc = epc;
1089 			err = SIGILL;
1090 			break;
1091 		}
1092 		break;
1093 
1094 	case beql_op:
1095 	case bnel_op:
1096 	case blezl_op:
1097 	case bgtzl_op:
1098 		if (delay_slot(regs)) {
1099 			err = SIGILL;
1100 			break;
1101 		}
1102 		regs->regs[31] = r31;
1103 		regs->cp0_epc = epc;
1104 		err = __compute_return_epc(regs);
1105 		if (err < 0)
1106 			return SIGEMT;
1107 		if (err != BRANCH_LIKELY_TAKEN)
1108 			break;
1109 		cpc = regs->cp0_epc;
1110 		nepc = epc + 4;
1111 		err = __get_user(nir, (u32 __user *)nepc);
1112 		if (err) {
1113 			err = SIGSEGV;
1114 			break;
1115 		}
1116 		/*
1117 		 * This will probably be optimized away when
1118 		 * CONFIG_DEBUG_FS is not enabled
1119 		 */
1120 		switch (MIPSInst_OPCODE(inst)) {
1121 		case beql_op:
1122 			MIPS_R2BR_STATS(beql);
1123 			break;
1124 		case bnel_op:
1125 			MIPS_R2BR_STATS(bnel);
1126 			break;
1127 		case blezl_op:
1128 			MIPS_R2BR_STATS(blezl);
1129 			break;
1130 		case bgtzl_op:
1131 			MIPS_R2BR_STATS(bgtzl);
1132 			break;
1133 		}
1134 
1135 		switch (MIPSInst_OPCODE(nir)) {
1136 		case cop1_op:
1137 		case cop1x_op:
1138 		case lwc1_op:
1139 		case swc1_op:
1140 			regs->cp0_cause |= CAUSEF_BD;
1141 			goto fpu_emul;
1142 		}
1143 		if (nir) {
1144 			err = mipsr6_emul(regs, nir);
1145 			if (err > 0) {
1146 				err = mips_dsemul(regs, nir, cpc);
1147 				if (err == SIGILL)
1148 					err = SIGEMT;
1149 				MIPS_R2_STATS(dsemul);
1150 			}
1151 		}
1152 		break;
1153 	case lwc1_op:
1154 	case swc1_op:
1155 	case cop1_op:
1156 	case cop1x_op:
1157 fpu_emul:
1158 		regs->regs[31] = r31;
1159 		regs->cp0_epc = epc;
1160 		if (!used_math()) {     /* First time FPU user.  */
1161 			err = init_fpu();
1162 			set_used_math();
1163 		}
1164 		lose_fpu(1);    /* Save FPU state for the emulator. */
1165 
1166 		err = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
1167 					       &fault_addr);
1168 
1169 		/*
1170 		 * this is a tricky issue - lose_fpu() uses LL/SC atomics
1171 		 * if FPU is owned and effectively cancels user level LL/SC.
1172 		 * So, it could be logical to don't restore FPU ownership here.
1173 		 * But the sequence of multiple FPU instructions is much much
1174 		 * more often than LL-FPU-SC and I prefer loop here until
1175 		 * next scheduler cycle cancels FPU ownership
1176 		 */
1177 		own_fpu(1);	/* Restore FPU state. */
1178 
1179 		if (err)
1180 			current->thread.cp0_baduaddr = (unsigned long)fault_addr;
1181 
1182 		MIPS_R2_STATS(fpus);
1183 
1184 		break;
1185 
1186 	case lwl_op:
1187 		rt = regs->regs[MIPSInst_RT(inst)];
1188 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1189 		if (!access_ok(VERIFY_READ, vaddr, 4)) {
1190 			current->thread.cp0_baduaddr = vaddr;
1191 			err = SIGSEGV;
1192 			break;
1193 		}
1194 		__asm__ __volatile__(
1195 			"	.set	push\n"
1196 			"	.set	reorder\n"
1197 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1198 			"1:"	LB	"%1, 0(%2)\n"
1199 				INS	"%0, %1, 24, 8\n"
1200 			"	andi	%1, %2, 0x3\n"
1201 			"	beq	$0, %1, 9f\n"
1202 				ADDIU	"%2, %2, -1\n"
1203 			"2:"	LB	"%1, 0(%2)\n"
1204 				INS	"%0, %1, 16, 8\n"
1205 			"	andi	%1, %2, 0x3\n"
1206 			"	beq	$0, %1, 9f\n"
1207 				ADDIU	"%2, %2, -1\n"
1208 			"3:"	LB	"%1, 0(%2)\n"
1209 				INS	"%0, %1, 8, 8\n"
1210 			"	andi	%1, %2, 0x3\n"
1211 			"	beq	$0, %1, 9f\n"
1212 				ADDIU	"%2, %2, -1\n"
1213 			"4:"	LB	"%1, 0(%2)\n"
1214 				INS	"%0, %1, 0, 8\n"
1215 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1216 			"1:"	LB	"%1, 0(%2)\n"
1217 				INS	"%0, %1, 24, 8\n"
1218 				ADDIU	"%2, %2, 1\n"
1219 			"	andi	%1, %2, 0x3\n"
1220 			"	beq	$0, %1, 9f\n"
1221 			"2:"	LB	"%1, 0(%2)\n"
1222 				INS	"%0, %1, 16, 8\n"
1223 				ADDIU	"%2, %2, 1\n"
1224 			"	andi	%1, %2, 0x3\n"
1225 			"	beq	$0, %1, 9f\n"
1226 			"3:"	LB	"%1, 0(%2)\n"
1227 				INS	"%0, %1, 8, 8\n"
1228 				ADDIU	"%2, %2, 1\n"
1229 			"	andi	%1, %2, 0x3\n"
1230 			"	beq	$0, %1, 9f\n"
1231 			"4:"	LB	"%1, 0(%2)\n"
1232 				INS	"%0, %1, 0, 8\n"
1233 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1234 			"9:	sll	%0, %0, 0\n"
1235 			"10:\n"
1236 			"	.insn\n"
1237 			"	.section	.fixup,\"ax\"\n"
1238 			"8:	li	%3,%4\n"
1239 			"	j	10b\n"
1240 			"	.previous\n"
1241 			"	.section	__ex_table,\"a\"\n"
1242 			"	.word	1b,8b\n"
1243 			"	.word	2b,8b\n"
1244 			"	.word	3b,8b\n"
1245 			"	.word	4b,8b\n"
1246 			"	.previous\n"
1247 			"	.set	pop\n"
1248 			: "+&r"(rt), "=&r"(rs),
1249 			  "+&r"(vaddr), "+&r"(err)
1250 			: "i"(SIGSEGV));
1251 
1252 		if (MIPSInst_RT(inst) && !err)
1253 			regs->regs[MIPSInst_RT(inst)] = rt;
1254 
1255 		MIPS_R2_STATS(loads);
1256 
1257 		break;
1258 
1259 	case lwr_op:
1260 		rt = regs->regs[MIPSInst_RT(inst)];
1261 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1262 		if (!access_ok(VERIFY_READ, vaddr, 4)) {
1263 			current->thread.cp0_baduaddr = vaddr;
1264 			err = SIGSEGV;
1265 			break;
1266 		}
1267 		__asm__ __volatile__(
1268 			"       .set	push\n"
1269 			"       .set	reorder\n"
1270 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1271 			"1:"    LB	"%1, 0(%2)\n"
1272 				INS	"%0, %1, 0, 8\n"
1273 				ADDIU	"%2, %2, 1\n"
1274 			"       andi	%1, %2, 0x3\n"
1275 			"       beq	$0, %1, 9f\n"
1276 			"2:"    LB	"%1, 0(%2)\n"
1277 				INS	"%0, %1, 8, 8\n"
1278 				ADDIU	"%2, %2, 1\n"
1279 			"       andi	%1, %2, 0x3\n"
1280 			"       beq	$0, %1, 9f\n"
1281 			"3:"    LB	"%1, 0(%2)\n"
1282 				INS	"%0, %1, 16, 8\n"
1283 				ADDIU	"%2, %2, 1\n"
1284 			"       andi	%1, %2, 0x3\n"
1285 			"       beq	$0, %1, 9f\n"
1286 			"4:"    LB	"%1, 0(%2)\n"
1287 				INS	"%0, %1, 24, 8\n"
1288 			"       sll	%0, %0, 0\n"
1289 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1290 			"1:"    LB	"%1, 0(%2)\n"
1291 				INS	"%0, %1, 0, 8\n"
1292 			"       andi	%1, %2, 0x3\n"
1293 			"       beq	$0, %1, 9f\n"
1294 				ADDIU	"%2, %2, -1\n"
1295 			"2:"    LB	"%1, 0(%2)\n"
1296 				INS	"%0, %1, 8, 8\n"
1297 			"       andi	%1, %2, 0x3\n"
1298 			"       beq	$0, %1, 9f\n"
1299 				ADDIU	"%2, %2, -1\n"
1300 			"3:"    LB	"%1, 0(%2)\n"
1301 				INS	"%0, %1, 16, 8\n"
1302 			"       andi	%1, %2, 0x3\n"
1303 			"       beq	$0, %1, 9f\n"
1304 				ADDIU	"%2, %2, -1\n"
1305 			"4:"    LB	"%1, 0(%2)\n"
1306 				INS	"%0, %1, 24, 8\n"
1307 			"       sll	%0, %0, 0\n"
1308 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1309 			"9:\n"
1310 			"10:\n"
1311 			"	.insn\n"
1312 			"	.section	.fixup,\"ax\"\n"
1313 			"8:	li	%3,%4\n"
1314 			"	j	10b\n"
1315 			"       .previous\n"
1316 			"	.section	__ex_table,\"a\"\n"
1317 			"	.word	1b,8b\n"
1318 			"	.word	2b,8b\n"
1319 			"	.word	3b,8b\n"
1320 			"	.word	4b,8b\n"
1321 			"	.previous\n"
1322 			"	.set	pop\n"
1323 			: "+&r"(rt), "=&r"(rs),
1324 			  "+&r"(vaddr), "+&r"(err)
1325 			: "i"(SIGSEGV));
1326 		if (MIPSInst_RT(inst) && !err)
1327 			regs->regs[MIPSInst_RT(inst)] = rt;
1328 
1329 		MIPS_R2_STATS(loads);
1330 
1331 		break;
1332 
1333 	case swl_op:
1334 		rt = regs->regs[MIPSInst_RT(inst)];
1335 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1336 		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
1337 			current->thread.cp0_baduaddr = vaddr;
1338 			err = SIGSEGV;
1339 			break;
1340 		}
1341 		__asm__ __volatile__(
1342 			"	.set	push\n"
1343 			"	.set	reorder\n"
1344 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1345 				EXT	"%1, %0, 24, 8\n"
1346 			"1:"	SB	"%1, 0(%2)\n"
1347 			"	andi	%1, %2, 0x3\n"
1348 			"	beq	$0, %1, 9f\n"
1349 				ADDIU	"%2, %2, -1\n"
1350 				EXT	"%1, %0, 16, 8\n"
1351 			"2:"	SB	"%1, 0(%2)\n"
1352 			"	andi	%1, %2, 0x3\n"
1353 			"	beq	$0, %1, 9f\n"
1354 				ADDIU	"%2, %2, -1\n"
1355 				EXT	"%1, %0, 8, 8\n"
1356 			"3:"	SB	"%1, 0(%2)\n"
1357 			"	andi	%1, %2, 0x3\n"
1358 			"	beq	$0, %1, 9f\n"
1359 				ADDIU	"%2, %2, -1\n"
1360 				EXT	"%1, %0, 0, 8\n"
1361 			"4:"	SB	"%1, 0(%2)\n"
1362 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1363 				EXT	"%1, %0, 24, 8\n"
1364 			"1:"	SB	"%1, 0(%2)\n"
1365 				ADDIU	"%2, %2, 1\n"
1366 			"	andi	%1, %2, 0x3\n"
1367 			"	beq	$0, %1, 9f\n"
1368 				EXT	"%1, %0, 16, 8\n"
1369 			"2:"	SB	"%1, 0(%2)\n"
1370 				ADDIU	"%2, %2, 1\n"
1371 			"	andi	%1, %2, 0x3\n"
1372 			"	beq	$0, %1, 9f\n"
1373 				EXT	"%1, %0, 8, 8\n"
1374 			"3:"	SB	"%1, 0(%2)\n"
1375 				ADDIU	"%2, %2, 1\n"
1376 			"	andi	%1, %2, 0x3\n"
1377 			"	beq	$0, %1, 9f\n"
1378 				EXT	"%1, %0, 0, 8\n"
1379 			"4:"	SB	"%1, 0(%2)\n"
1380 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1381 			"9:\n"
1382 			"	.insn\n"
1383 			"       .section        .fixup,\"ax\"\n"
1384 			"8:	li	%3,%4\n"
1385 			"	j	9b\n"
1386 			"	.previous\n"
1387 			"	.section        __ex_table,\"a\"\n"
1388 			"	.word	1b,8b\n"
1389 			"	.word	2b,8b\n"
1390 			"	.word	3b,8b\n"
1391 			"	.word	4b,8b\n"
1392 			"	.previous\n"
1393 			"	.set	pop\n"
1394 			: "+&r"(rt), "=&r"(rs),
1395 			  "+&r"(vaddr), "+&r"(err)
1396 			: "i"(SIGSEGV)
1397 			: "memory");
1398 
1399 		MIPS_R2_STATS(stores);
1400 
1401 		break;
1402 
1403 	case swr_op:
1404 		rt = regs->regs[MIPSInst_RT(inst)];
1405 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1406 		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
1407 			current->thread.cp0_baduaddr = vaddr;
1408 			err = SIGSEGV;
1409 			break;
1410 		}
1411 		__asm__ __volatile__(
1412 			"	.set	push\n"
1413 			"	.set	reorder\n"
1414 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1415 				EXT	"%1, %0, 0, 8\n"
1416 			"1:"	SB	"%1, 0(%2)\n"
1417 				ADDIU	"%2, %2, 1\n"
1418 			"	andi	%1, %2, 0x3\n"
1419 			"	beq	$0, %1, 9f\n"
1420 				EXT	"%1, %0, 8, 8\n"
1421 			"2:"	SB	"%1, 0(%2)\n"
1422 				ADDIU	"%2, %2, 1\n"
1423 			"	andi	%1, %2, 0x3\n"
1424 			"	beq	$0, %1, 9f\n"
1425 				EXT	"%1, %0, 16, 8\n"
1426 			"3:"	SB	"%1, 0(%2)\n"
1427 				ADDIU	"%2, %2, 1\n"
1428 			"	andi	%1, %2, 0x3\n"
1429 			"	beq	$0, %1, 9f\n"
1430 				EXT	"%1, %0, 24, 8\n"
1431 			"4:"	SB	"%1, 0(%2)\n"
1432 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1433 				EXT	"%1, %0, 0, 8\n"
1434 			"1:"	SB	"%1, 0(%2)\n"
1435 			"	andi	%1, %2, 0x3\n"
1436 			"	beq	$0, %1, 9f\n"
1437 				ADDIU	"%2, %2, -1\n"
1438 				EXT	"%1, %0, 8, 8\n"
1439 			"2:"	SB	"%1, 0(%2)\n"
1440 			"	andi	%1, %2, 0x3\n"
1441 			"	beq	$0, %1, 9f\n"
1442 				ADDIU	"%2, %2, -1\n"
1443 				EXT	"%1, %0, 16, 8\n"
1444 			"3:"	SB	"%1, 0(%2)\n"
1445 			"	andi	%1, %2, 0x3\n"
1446 			"	beq	$0, %1, 9f\n"
1447 				ADDIU	"%2, %2, -1\n"
1448 				EXT	"%1, %0, 24, 8\n"
1449 			"4:"	SB	"%1, 0(%2)\n"
1450 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1451 			"9:\n"
1452 			"	.insn\n"
1453 			"	.section        .fixup,\"ax\"\n"
1454 			"8:	li	%3,%4\n"
1455 			"	j	9b\n"
1456 			"	.previous\n"
1457 			"	.section        __ex_table,\"a\"\n"
1458 			"	.word	1b,8b\n"
1459 			"	.word	2b,8b\n"
1460 			"	.word	3b,8b\n"
1461 			"	.word	4b,8b\n"
1462 			"	.previous\n"
1463 			"	.set	pop\n"
1464 			: "+&r"(rt), "=&r"(rs),
1465 			  "+&r"(vaddr), "+&r"(err)
1466 			: "i"(SIGSEGV)
1467 			: "memory");
1468 
1469 		MIPS_R2_STATS(stores);
1470 
1471 		break;
1472 
1473 	case ldl_op:
1474 		if (config_enabled(CONFIG_32BIT)) {
1475 		    err = SIGILL;
1476 		    break;
1477 		}
1478 
1479 		rt = regs->regs[MIPSInst_RT(inst)];
1480 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1481 		if (!access_ok(VERIFY_READ, vaddr, 8)) {
1482 			current->thread.cp0_baduaddr = vaddr;
1483 			err = SIGSEGV;
1484 			break;
1485 		}
1486 		__asm__ __volatile__(
1487 			"	.set    push\n"
1488 			"	.set    reorder\n"
1489 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1490 			"1:	lb	%1, 0(%2)\n"
1491 			"	dinsu	%0, %1, 56, 8\n"
1492 			"	andi	%1, %2, 0x7\n"
1493 			"	beq	$0, %1, 9f\n"
1494 			"	daddiu	%2, %2, -1\n"
1495 			"2:	lb	%1, 0(%2)\n"
1496 			"	dinsu	%0, %1, 48, 8\n"
1497 			"	andi	%1, %2, 0x7\n"
1498 			"	beq	$0, %1, 9f\n"
1499 			"	daddiu	%2, %2, -1\n"
1500 			"3:	lb	%1, 0(%2)\n"
1501 			"	dinsu	%0, %1, 40, 8\n"
1502 			"	andi	%1, %2, 0x7\n"
1503 			"	beq	$0, %1, 9f\n"
1504 			"	daddiu	%2, %2, -1\n"
1505 			"4:	lb	%1, 0(%2)\n"
1506 			"	dinsu	%0, %1, 32, 8\n"
1507 			"	andi	%1, %2, 0x7\n"
1508 			"	beq	$0, %1, 9f\n"
1509 			"	daddiu	%2, %2, -1\n"
1510 			"5:	lb	%1, 0(%2)\n"
1511 			"	dins	%0, %1, 24, 8\n"
1512 			"	andi	%1, %2, 0x7\n"
1513 			"	beq	$0, %1, 9f\n"
1514 			"	daddiu	%2, %2, -1\n"
1515 			"6:	lb	%1, 0(%2)\n"
1516 			"	dins	%0, %1, 16, 8\n"
1517 			"	andi	%1, %2, 0x7\n"
1518 			"	beq	$0, %1, 9f\n"
1519 			"	daddiu	%2, %2, -1\n"
1520 			"7:	lb	%1, 0(%2)\n"
1521 			"	dins	%0, %1, 8, 8\n"
1522 			"	andi	%1, %2, 0x7\n"
1523 			"	beq	$0, %1, 9f\n"
1524 			"	daddiu	%2, %2, -1\n"
1525 			"0:	lb	%1, 0(%2)\n"
1526 			"	dins	%0, %1, 0, 8\n"
1527 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1528 			"1:	lb	%1, 0(%2)\n"
1529 			"	dinsu	%0, %1, 56, 8\n"
1530 			"	daddiu	%2, %2, 1\n"
1531 			"	andi	%1, %2, 0x7\n"
1532 			"	beq	$0, %1, 9f\n"
1533 			"2:	lb	%1, 0(%2)\n"
1534 			"	dinsu	%0, %1, 48, 8\n"
1535 			"	daddiu	%2, %2, 1\n"
1536 			"	andi	%1, %2, 0x7\n"
1537 			"	beq	$0, %1, 9f\n"
1538 			"3:	lb	%1, 0(%2)\n"
1539 			"	dinsu	%0, %1, 40, 8\n"
1540 			"	daddiu  %2, %2, 1\n"
1541 			"	andi	%1, %2, 0x7\n"
1542 			"	beq	$0, %1, 9f\n"
1543 			"4:	lb	%1, 0(%2)\n"
1544 			"	dinsu	%0, %1, 32, 8\n"
1545 			"	daddiu	%2, %2, 1\n"
1546 			"	andi	%1, %2, 0x7\n"
1547 			"	beq	$0, %1, 9f\n"
1548 			"5:	lb	%1, 0(%2)\n"
1549 			"	dins	%0, %1, 24, 8\n"
1550 			"	daddiu	%2, %2, 1\n"
1551 			"	andi	%1, %2, 0x7\n"
1552 			"	beq	$0, %1, 9f\n"
1553 			"6:	lb	%1, 0(%2)\n"
1554 			"	dins	%0, %1, 16, 8\n"
1555 			"	daddiu	%2, %2, 1\n"
1556 			"	andi	%1, %2, 0x7\n"
1557 			"	beq	$0, %1, 9f\n"
1558 			"7:	lb	%1, 0(%2)\n"
1559 			"	dins	%0, %1, 8, 8\n"
1560 			"	daddiu	%2, %2, 1\n"
1561 			"	andi	%1, %2, 0x7\n"
1562 			"	beq	$0, %1, 9f\n"
1563 			"0:	lb	%1, 0(%2)\n"
1564 			"	dins	%0, %1, 0, 8\n"
1565 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1566 			"9:\n"
1567 			"	.insn\n"
1568 			"	.section        .fixup,\"ax\"\n"
1569 			"8:	li	%3,%4\n"
1570 			"	j	9b\n"
1571 			"	.previous\n"
1572 			"	.section        __ex_table,\"a\"\n"
1573 			"	.word	1b,8b\n"
1574 			"	.word	2b,8b\n"
1575 			"	.word	3b,8b\n"
1576 			"	.word	4b,8b\n"
1577 			"	.word	5b,8b\n"
1578 			"	.word	6b,8b\n"
1579 			"	.word	7b,8b\n"
1580 			"	.word	0b,8b\n"
1581 			"	.previous\n"
1582 			"	.set	pop\n"
1583 			: "+&r"(rt), "=&r"(rs),
1584 			  "+&r"(vaddr), "+&r"(err)
1585 			: "i"(SIGSEGV));
1586 		if (MIPSInst_RT(inst) && !err)
1587 			regs->regs[MIPSInst_RT(inst)] = rt;
1588 
1589 		MIPS_R2_STATS(loads);
1590 		break;
1591 
1592 	case ldr_op:
1593 		if (config_enabled(CONFIG_32BIT)) {
1594 		    err = SIGILL;
1595 		    break;
1596 		}
1597 
1598 		rt = regs->regs[MIPSInst_RT(inst)];
1599 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1600 		if (!access_ok(VERIFY_READ, vaddr, 8)) {
1601 			current->thread.cp0_baduaddr = vaddr;
1602 			err = SIGSEGV;
1603 			break;
1604 		}
1605 		__asm__ __volatile__(
1606 			"	.set    push\n"
1607 			"	.set    reorder\n"
1608 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1609 			"1:	lb      %1, 0(%2)\n"
1610 			"	dins   %0, %1, 0, 8\n"
1611 			"	daddiu  %2, %2, 1\n"
1612 			"	andi    %1, %2, 0x7\n"
1613 			"	beq     $0, %1, 9f\n"
1614 			"2:	lb      %1, 0(%2)\n"
1615 			"	dins   %0, %1, 8, 8\n"
1616 			"	daddiu  %2, %2, 1\n"
1617 			"	andi    %1, %2, 0x7\n"
1618 			"	beq     $0, %1, 9f\n"
1619 			"3:	lb      %1, 0(%2)\n"
1620 			"	dins   %0, %1, 16, 8\n"
1621 			"	daddiu  %2, %2, 1\n"
1622 			"	andi    %1, %2, 0x7\n"
1623 			"	beq     $0, %1, 9f\n"
1624 			"4:	lb      %1, 0(%2)\n"
1625 			"	dins   %0, %1, 24, 8\n"
1626 			"	daddiu  %2, %2, 1\n"
1627 			"	andi    %1, %2, 0x7\n"
1628 			"	beq     $0, %1, 9f\n"
1629 			"5:	lb      %1, 0(%2)\n"
1630 			"	dinsu    %0, %1, 32, 8\n"
1631 			"	daddiu  %2, %2, 1\n"
1632 			"	andi    %1, %2, 0x7\n"
1633 			"	beq     $0, %1, 9f\n"
1634 			"6:	lb      %1, 0(%2)\n"
1635 			"	dinsu    %0, %1, 40, 8\n"
1636 			"	daddiu  %2, %2, 1\n"
1637 			"	andi    %1, %2, 0x7\n"
1638 			"	beq     $0, %1, 9f\n"
1639 			"7:	lb      %1, 0(%2)\n"
1640 			"	dinsu    %0, %1, 48, 8\n"
1641 			"	daddiu  %2, %2, 1\n"
1642 			"	andi    %1, %2, 0x7\n"
1643 			"	beq     $0, %1, 9f\n"
1644 			"0:	lb      %1, 0(%2)\n"
1645 			"	dinsu    %0, %1, 56, 8\n"
1646 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1647 			"1:	lb      %1, 0(%2)\n"
1648 			"	dins   %0, %1, 0, 8\n"
1649 			"	andi    %1, %2, 0x7\n"
1650 			"	beq     $0, %1, 9f\n"
1651 			"	daddiu  %2, %2, -1\n"
1652 			"2:	lb      %1, 0(%2)\n"
1653 			"	dins   %0, %1, 8, 8\n"
1654 			"	andi    %1, %2, 0x7\n"
1655 			"	beq     $0, %1, 9f\n"
1656 			"	daddiu  %2, %2, -1\n"
1657 			"3:	lb      %1, 0(%2)\n"
1658 			"	dins   %0, %1, 16, 8\n"
1659 			"	andi    %1, %2, 0x7\n"
1660 			"	beq     $0, %1, 9f\n"
1661 			"	daddiu  %2, %2, -1\n"
1662 			"4:	lb      %1, 0(%2)\n"
1663 			"	dins   %0, %1, 24, 8\n"
1664 			"	andi    %1, %2, 0x7\n"
1665 			"	beq     $0, %1, 9f\n"
1666 			"	daddiu  %2, %2, -1\n"
1667 			"5:	lb      %1, 0(%2)\n"
1668 			"	dinsu    %0, %1, 32, 8\n"
1669 			"	andi    %1, %2, 0x7\n"
1670 			"	beq     $0, %1, 9f\n"
1671 			"	daddiu  %2, %2, -1\n"
1672 			"6:	lb      %1, 0(%2)\n"
1673 			"	dinsu    %0, %1, 40, 8\n"
1674 			"	andi    %1, %2, 0x7\n"
1675 			"	beq     $0, %1, 9f\n"
1676 			"	daddiu  %2, %2, -1\n"
1677 			"7:	lb      %1, 0(%2)\n"
1678 			"	dinsu    %0, %1, 48, 8\n"
1679 			"	andi    %1, %2, 0x7\n"
1680 			"	beq     $0, %1, 9f\n"
1681 			"	daddiu  %2, %2, -1\n"
1682 			"0:	lb      %1, 0(%2)\n"
1683 			"	dinsu    %0, %1, 56, 8\n"
1684 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1685 			"9:\n"
1686 			"	.insn\n"
1687 			"	.section        .fixup,\"ax\"\n"
1688 			"8:	li     %3,%4\n"
1689 			"	j      9b\n"
1690 			"	.previous\n"
1691 			"	.section        __ex_table,\"a\"\n"
1692 			"	.word  1b,8b\n"
1693 			"	.word  2b,8b\n"
1694 			"	.word  3b,8b\n"
1695 			"	.word  4b,8b\n"
1696 			"	.word  5b,8b\n"
1697 			"	.word  6b,8b\n"
1698 			"	.word  7b,8b\n"
1699 			"	.word  0b,8b\n"
1700 			"	.previous\n"
1701 			"	.set    pop\n"
1702 			: "+&r"(rt), "=&r"(rs),
1703 			  "+&r"(vaddr), "+&r"(err)
1704 			: "i"(SIGSEGV));
1705 		if (MIPSInst_RT(inst) && !err)
1706 			regs->regs[MIPSInst_RT(inst)] = rt;
1707 
1708 		MIPS_R2_STATS(loads);
1709 		break;
1710 
1711 	case sdl_op:
1712 		if (config_enabled(CONFIG_32BIT)) {
1713 		    err = SIGILL;
1714 		    break;
1715 		}
1716 
1717 		rt = regs->regs[MIPSInst_RT(inst)];
1718 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1719 		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
1720 			current->thread.cp0_baduaddr = vaddr;
1721 			err = SIGSEGV;
1722 			break;
1723 		}
1724 		__asm__ __volatile__(
1725 			"	.set	push\n"
1726 			"	.set	reorder\n"
1727 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1728 			"	dextu	%1, %0, 56, 8\n"
1729 			"1:	sb	%1, 0(%2)\n"
1730 			"	andi	%1, %2, 0x7\n"
1731 			"	beq	$0, %1, 9f\n"
1732 			"	daddiu	%2, %2, -1\n"
1733 			"	dextu	%1, %0, 48, 8\n"
1734 			"2:	sb	%1, 0(%2)\n"
1735 			"	andi	%1, %2, 0x7\n"
1736 			"	beq	$0, %1, 9f\n"
1737 			"	daddiu	%2, %2, -1\n"
1738 			"	dextu	%1, %0, 40, 8\n"
1739 			"3:	sb	%1, 0(%2)\n"
1740 			"	andi	%1, %2, 0x7\n"
1741 			"	beq	$0, %1, 9f\n"
1742 			"	daddiu	%2, %2, -1\n"
1743 			"	dextu	%1, %0, 32, 8\n"
1744 			"4:	sb	%1, 0(%2)\n"
1745 			"	andi	%1, %2, 0x7\n"
1746 			"	beq	$0, %1, 9f\n"
1747 			"	daddiu	%2, %2, -1\n"
1748 			"	dext	%1, %0, 24, 8\n"
1749 			"5:	sb	%1, 0(%2)\n"
1750 			"	andi	%1, %2, 0x7\n"
1751 			"	beq	$0, %1, 9f\n"
1752 			"	daddiu	%2, %2, -1\n"
1753 			"	dext	%1, %0, 16, 8\n"
1754 			"6:	sb	%1, 0(%2)\n"
1755 			"	andi	%1, %2, 0x7\n"
1756 			"	beq	$0, %1, 9f\n"
1757 			"	daddiu	%2, %2, -1\n"
1758 			"	dext	%1, %0, 8, 8\n"
1759 			"7:	sb	%1, 0(%2)\n"
1760 			"	andi	%1, %2, 0x7\n"
1761 			"	beq	$0, %1, 9f\n"
1762 			"	daddiu	%2, %2, -1\n"
1763 			"	dext	%1, %0, 0, 8\n"
1764 			"0:	sb	%1, 0(%2)\n"
1765 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1766 			"	dextu	%1, %0, 56, 8\n"
1767 			"1:	sb	%1, 0(%2)\n"
1768 			"	daddiu	%2, %2, 1\n"
1769 			"	andi	%1, %2, 0x7\n"
1770 			"	beq	$0, %1, 9f\n"
1771 			"	dextu	%1, %0, 48, 8\n"
1772 			"2:	sb	%1, 0(%2)\n"
1773 			"	daddiu	%2, %2, 1\n"
1774 			"	andi	%1, %2, 0x7\n"
1775 			"	beq	$0, %1, 9f\n"
1776 			"	dextu	%1, %0, 40, 8\n"
1777 			"3:	sb	%1, 0(%2)\n"
1778 			"	daddiu	%2, %2, 1\n"
1779 			"	andi	%1, %2, 0x7\n"
1780 			"	beq	$0, %1, 9f\n"
1781 			"	dextu	%1, %0, 32, 8\n"
1782 			"4:	sb	%1, 0(%2)\n"
1783 			"	daddiu	%2, %2, 1\n"
1784 			"	andi	%1, %2, 0x7\n"
1785 			"	beq	$0, %1, 9f\n"
1786 			"	dext	%1, %0, 24, 8\n"
1787 			"5:	sb	%1, 0(%2)\n"
1788 			"	daddiu	%2, %2, 1\n"
1789 			"	andi	%1, %2, 0x7\n"
1790 			"	beq	$0, %1, 9f\n"
1791 			"	dext	%1, %0, 16, 8\n"
1792 			"6:	sb	%1, 0(%2)\n"
1793 			"	daddiu	%2, %2, 1\n"
1794 			"	andi	%1, %2, 0x7\n"
1795 			"	beq	$0, %1, 9f\n"
1796 			"	dext	%1, %0, 8, 8\n"
1797 			"7:	sb	%1, 0(%2)\n"
1798 			"	daddiu	%2, %2, 1\n"
1799 			"	andi	%1, %2, 0x7\n"
1800 			"	beq	$0, %1, 9f\n"
1801 			"	dext	%1, %0, 0, 8\n"
1802 			"0:	sb	%1, 0(%2)\n"
1803 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1804 			"9:\n"
1805 			"	.insn\n"
1806 			"	.section        .fixup,\"ax\"\n"
1807 			"8:	li	%3,%4\n"
1808 			"	j	9b\n"
1809 			"	.previous\n"
1810 			"	.section        __ex_table,\"a\"\n"
1811 			"	.word	1b,8b\n"
1812 			"	.word	2b,8b\n"
1813 			"	.word	3b,8b\n"
1814 			"	.word	4b,8b\n"
1815 			"	.word	5b,8b\n"
1816 			"	.word	6b,8b\n"
1817 			"	.word	7b,8b\n"
1818 			"	.word	0b,8b\n"
1819 			"	.previous\n"
1820 			"	.set	pop\n"
1821 			: "+&r"(rt), "=&r"(rs),
1822 			  "+&r"(vaddr), "+&r"(err)
1823 			: "i"(SIGSEGV)
1824 			: "memory");
1825 
1826 		MIPS_R2_STATS(stores);
1827 		break;
1828 
1829 	case sdr_op:
1830 		if (config_enabled(CONFIG_32BIT)) {
1831 		    err = SIGILL;
1832 		    break;
1833 		}
1834 
1835 		rt = regs->regs[MIPSInst_RT(inst)];
1836 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1837 		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
1838 			current->thread.cp0_baduaddr = vaddr;
1839 			err = SIGSEGV;
1840 			break;
1841 		}
1842 		__asm__ __volatile__(
1843 			"       .set	push\n"
1844 			"       .set	reorder\n"
1845 #ifdef CONFIG_CPU_LITTLE_ENDIAN
1846 			"       dext	%1, %0, 0, 8\n"
1847 			"1:     sb	%1, 0(%2)\n"
1848 			"       daddiu	%2, %2, 1\n"
1849 			"       andi	%1, %2, 0x7\n"
1850 			"       beq	$0, %1, 9f\n"
1851 			"       dext	%1, %0, 8, 8\n"
1852 			"2:     sb	%1, 0(%2)\n"
1853 			"       daddiu	%2, %2, 1\n"
1854 			"       andi	%1, %2, 0x7\n"
1855 			"       beq	$0, %1, 9f\n"
1856 			"       dext	%1, %0, 16, 8\n"
1857 			"3:     sb	%1, 0(%2)\n"
1858 			"       daddiu	%2, %2, 1\n"
1859 			"       andi	%1, %2, 0x7\n"
1860 			"       beq	$0, %1, 9f\n"
1861 			"       dext	%1, %0, 24, 8\n"
1862 			"4:     sb	%1, 0(%2)\n"
1863 			"       daddiu	%2, %2, 1\n"
1864 			"       andi	%1, %2, 0x7\n"
1865 			"       beq	$0, %1, 9f\n"
1866 			"       dextu	%1, %0, 32, 8\n"
1867 			"5:     sb	%1, 0(%2)\n"
1868 			"       daddiu	%2, %2, 1\n"
1869 			"       andi	%1, %2, 0x7\n"
1870 			"       beq	$0, %1, 9f\n"
1871 			"       dextu	%1, %0, 40, 8\n"
1872 			"6:     sb	%1, 0(%2)\n"
1873 			"       daddiu	%2, %2, 1\n"
1874 			"       andi	%1, %2, 0x7\n"
1875 			"       beq	$0, %1, 9f\n"
1876 			"       dextu	%1, %0, 48, 8\n"
1877 			"7:     sb	%1, 0(%2)\n"
1878 			"       daddiu	%2, %2, 1\n"
1879 			"       andi	%1, %2, 0x7\n"
1880 			"       beq	$0, %1, 9f\n"
1881 			"       dextu	%1, %0, 56, 8\n"
1882 			"0:     sb	%1, 0(%2)\n"
1883 #else /* !CONFIG_CPU_LITTLE_ENDIAN */
1884 			"       dext	%1, %0, 0, 8\n"
1885 			"1:     sb	%1, 0(%2)\n"
1886 			"       andi	%1, %2, 0x7\n"
1887 			"       beq	$0, %1, 9f\n"
1888 			"       daddiu	%2, %2, -1\n"
1889 			"       dext	%1, %0, 8, 8\n"
1890 			"2:     sb	%1, 0(%2)\n"
1891 			"       andi	%1, %2, 0x7\n"
1892 			"       beq	$0, %1, 9f\n"
1893 			"       daddiu	%2, %2, -1\n"
1894 			"       dext	%1, %0, 16, 8\n"
1895 			"3:     sb	%1, 0(%2)\n"
1896 			"       andi	%1, %2, 0x7\n"
1897 			"       beq	$0, %1, 9f\n"
1898 			"       daddiu	%2, %2, -1\n"
1899 			"       dext	%1, %0, 24, 8\n"
1900 			"4:     sb	%1, 0(%2)\n"
1901 			"       andi	%1, %2, 0x7\n"
1902 			"       beq	$0, %1, 9f\n"
1903 			"       daddiu	%2, %2, -1\n"
1904 			"       dextu	%1, %0, 32, 8\n"
1905 			"5:     sb	%1, 0(%2)\n"
1906 			"       andi	%1, %2, 0x7\n"
1907 			"       beq	$0, %1, 9f\n"
1908 			"       daddiu	%2, %2, -1\n"
1909 			"       dextu	%1, %0, 40, 8\n"
1910 			"6:     sb	%1, 0(%2)\n"
1911 			"       andi	%1, %2, 0x7\n"
1912 			"       beq	$0, %1, 9f\n"
1913 			"       daddiu	%2, %2, -1\n"
1914 			"       dextu	%1, %0, 48, 8\n"
1915 			"7:     sb	%1, 0(%2)\n"
1916 			"       andi	%1, %2, 0x7\n"
1917 			"       beq	$0, %1, 9f\n"
1918 			"       daddiu	%2, %2, -1\n"
1919 			"       dextu	%1, %0, 56, 8\n"
1920 			"0:     sb	%1, 0(%2)\n"
1921 #endif /* CONFIG_CPU_LITTLE_ENDIAN */
1922 			"9:\n"
1923 			"       .insn\n"
1924 			"       .section        .fixup,\"ax\"\n"
1925 			"8:     li	%3,%4\n"
1926 			"       j	9b\n"
1927 			"       .previous\n"
1928 			"       .section        __ex_table,\"a\"\n"
1929 			"       .word	1b,8b\n"
1930 			"       .word	2b,8b\n"
1931 			"       .word	3b,8b\n"
1932 			"       .word	4b,8b\n"
1933 			"       .word	5b,8b\n"
1934 			"       .word	6b,8b\n"
1935 			"       .word	7b,8b\n"
1936 			"       .word	0b,8b\n"
1937 			"       .previous\n"
1938 			"       .set	pop\n"
1939 			: "+&r"(rt), "=&r"(rs),
1940 			  "+&r"(vaddr), "+&r"(err)
1941 			: "i"(SIGSEGV)
1942 			: "memory");
1943 
1944 		MIPS_R2_STATS(stores);
1945 
1946 		break;
1947 	case ll_op:
1948 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
1949 		if (vaddr & 0x3) {
1950 			current->thread.cp0_baduaddr = vaddr;
1951 			err = SIGBUS;
1952 			break;
1953 		}
1954 		if (!access_ok(VERIFY_READ, vaddr, 4)) {
1955 			current->thread.cp0_baduaddr = vaddr;
1956 			err = SIGBUS;
1957 			break;
1958 		}
1959 
1960 		if (!cpu_has_rw_llb) {
1961 			/*
1962 			 * An LL/SC block can't be safely emulated without
1963 			 * a Config5/LLB availability. So it's probably time to
1964 			 * kill our process before things get any worse. This is
1965 			 * because Config5/LLB allows us to use ERETNC so that
1966 			 * the LLAddr/LLB bit is not cleared when we return from
1967 			 * an exception. MIPS R2 LL/SC instructions trap with an
1968 			 * RI exception so once we emulate them here, we return
1969 			 * back to userland with ERETNC. That preserves the
1970 			 * LLAddr/LLB so the subsequent SC instruction will
1971 			 * succeed preserving the atomic semantics of the LL/SC
1972 			 * block. Without that, there is no safe way to emulate
1973 			 * an LL/SC block in MIPSR2 userland.
1974 			 */
1975 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
1976 			err = SIGKILL;
1977 			break;
1978 		}
1979 
1980 		__asm__ __volatile__(
1981 			"1:\n"
1982 			"ll	%0, 0(%2)\n"
1983 			"2:\n"
1984 			".insn\n"
1985 			".section        .fixup,\"ax\"\n"
1986 			"3:\n"
1987 			"li	%1, %3\n"
1988 			"j	2b\n"
1989 			".previous\n"
1990 			".section        __ex_table,\"a\"\n"
1991 			".word  1b, 3b\n"
1992 			".previous\n"
1993 			: "=&r"(res), "+&r"(err)
1994 			: "r"(vaddr), "i"(SIGSEGV)
1995 			: "memory");
1996 
1997 		if (MIPSInst_RT(inst) && !err)
1998 			regs->regs[MIPSInst_RT(inst)] = res;
1999 		MIPS_R2_STATS(llsc);
2000 
2001 		break;
2002 
2003 	case sc_op:
2004 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
2005 		if (vaddr & 0x3) {
2006 			current->thread.cp0_baduaddr = vaddr;
2007 			err = SIGBUS;
2008 			break;
2009 		}
2010 		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
2011 			current->thread.cp0_baduaddr = vaddr;
2012 			err = SIGBUS;
2013 			break;
2014 		}
2015 
2016 		if (!cpu_has_rw_llb) {
2017 			/*
2018 			 * An LL/SC block can't be safely emulated without
2019 			 * a Config5/LLB availability. So it's probably time to
2020 			 * kill our process before things get any worse. This is
2021 			 * because Config5/LLB allows us to use ERETNC so that
2022 			 * the LLAddr/LLB bit is not cleared when we return from
2023 			 * an exception. MIPS R2 LL/SC instructions trap with an
2024 			 * RI exception so once we emulate them here, we return
2025 			 * back to userland with ERETNC. That preserves the
2026 			 * LLAddr/LLB so the subsequent SC instruction will
2027 			 * succeed preserving the atomic semantics of the LL/SC
2028 			 * block. Without that, there is no safe way to emulate
2029 			 * an LL/SC block in MIPSR2 userland.
2030 			 */
2031 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
2032 			err = SIGKILL;
2033 			break;
2034 		}
2035 
2036 		res = regs->regs[MIPSInst_RT(inst)];
2037 
2038 		__asm__ __volatile__(
2039 			"1:\n"
2040 			"sc	%0, 0(%2)\n"
2041 			"2:\n"
2042 			".insn\n"
2043 			".section        .fixup,\"ax\"\n"
2044 			"3:\n"
2045 			"li	%1, %3\n"
2046 			"j	2b\n"
2047 			".previous\n"
2048 			".section        __ex_table,\"a\"\n"
2049 			".word	1b, 3b\n"
2050 			".previous\n"
2051 			: "+&r"(res), "+&r"(err)
2052 			: "r"(vaddr), "i"(SIGSEGV));
2053 
2054 		if (MIPSInst_RT(inst) && !err)
2055 			regs->regs[MIPSInst_RT(inst)] = res;
2056 
2057 		MIPS_R2_STATS(llsc);
2058 
2059 		break;
2060 
2061 	case lld_op:
2062 		if (config_enabled(CONFIG_32BIT)) {
2063 		    err = SIGILL;
2064 		    break;
2065 		}
2066 
2067 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
2068 		if (vaddr & 0x7) {
2069 			current->thread.cp0_baduaddr = vaddr;
2070 			err = SIGBUS;
2071 			break;
2072 		}
2073 		if (!access_ok(VERIFY_READ, vaddr, 8)) {
2074 			current->thread.cp0_baduaddr = vaddr;
2075 			err = SIGBUS;
2076 			break;
2077 		}
2078 
2079 		if (!cpu_has_rw_llb) {
2080 			/*
2081 			 * An LL/SC block can't be safely emulated without
2082 			 * a Config5/LLB availability. So it's probably time to
2083 			 * kill our process before things get any worse. This is
2084 			 * because Config5/LLB allows us to use ERETNC so that
2085 			 * the LLAddr/LLB bit is not cleared when we return from
2086 			 * an exception. MIPS R2 LL/SC instructions trap with an
2087 			 * RI exception so once we emulate them here, we return
2088 			 * back to userland with ERETNC. That preserves the
2089 			 * LLAddr/LLB so the subsequent SC instruction will
2090 			 * succeed preserving the atomic semantics of the LL/SC
2091 			 * block. Without that, there is no safe way to emulate
2092 			 * an LL/SC block in MIPSR2 userland.
2093 			 */
2094 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
2095 			err = SIGKILL;
2096 			break;
2097 		}
2098 
2099 		__asm__ __volatile__(
2100 			"1:\n"
2101 			"lld	%0, 0(%2)\n"
2102 			"2:\n"
2103 			".insn\n"
2104 			".section        .fixup,\"ax\"\n"
2105 			"3:\n"
2106 			"li	%1, %3\n"
2107 			"j	2b\n"
2108 			".previous\n"
2109 			".section        __ex_table,\"a\"\n"
2110 			".word  1b, 3b\n"
2111 			".previous\n"
2112 			: "=&r"(res), "+&r"(err)
2113 			: "r"(vaddr), "i"(SIGSEGV)
2114 			: "memory");
2115 		if (MIPSInst_RT(inst) && !err)
2116 			regs->regs[MIPSInst_RT(inst)] = res;
2117 
2118 		MIPS_R2_STATS(llsc);
2119 
2120 		break;
2121 
2122 	case scd_op:
2123 		if (config_enabled(CONFIG_32BIT)) {
2124 		    err = SIGILL;
2125 		    break;
2126 		}
2127 
2128 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
2129 		if (vaddr & 0x7) {
2130 			current->thread.cp0_baduaddr = vaddr;
2131 			err = SIGBUS;
2132 			break;
2133 		}
2134 		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
2135 			current->thread.cp0_baduaddr = vaddr;
2136 			err = SIGBUS;
2137 			break;
2138 		}
2139 
2140 		if (!cpu_has_rw_llb) {
2141 			/*
2142 			 * An LL/SC block can't be safely emulated without
2143 			 * a Config5/LLB availability. So it's probably time to
2144 			 * kill our process before things get any worse. This is
2145 			 * because Config5/LLB allows us to use ERETNC so that
2146 			 * the LLAddr/LLB bit is not cleared when we return from
2147 			 * an exception. MIPS R2 LL/SC instructions trap with an
2148 			 * RI exception so once we emulate them here, we return
2149 			 * back to userland with ERETNC. That preserves the
2150 			 * LLAddr/LLB so the subsequent SC instruction will
2151 			 * succeed preserving the atomic semantics of the LL/SC
2152 			 * block. Without that, there is no safe way to emulate
2153 			 * an LL/SC block in MIPSR2 userland.
2154 			 */
2155 			pr_err("Can't emulate MIPSR2 LL/SC without Config5/LLB\n");
2156 			err = SIGKILL;
2157 			break;
2158 		}
2159 
2160 		res = regs->regs[MIPSInst_RT(inst)];
2161 
2162 		__asm__ __volatile__(
2163 			"1:\n"
2164 			"scd	%0, 0(%2)\n"
2165 			"2:\n"
2166 			".insn\n"
2167 			".section        .fixup,\"ax\"\n"
2168 			"3:\n"
2169 			"li	%1, %3\n"
2170 			"j	2b\n"
2171 			".previous\n"
2172 			".section        __ex_table,\"a\"\n"
2173 			".word	1b, 3b\n"
2174 			".previous\n"
2175 			: "+&r"(res), "+&r"(err)
2176 			: "r"(vaddr), "i"(SIGSEGV));
2177 
2178 		if (MIPSInst_RT(inst) && !err)
2179 			regs->regs[MIPSInst_RT(inst)] = res;
2180 
2181 		MIPS_R2_STATS(llsc);
2182 
2183 		break;
2184 	case pref_op:
2185 		/* skip it */
2186 		break;
2187 	default:
2188 		err = SIGILL;
2189 	}
2190 
2191 	/*
2192 	 * Lets not return to userland just yet. It's constly and
2193 	 * it's likely we have more R2 instructions to emulate
2194 	 */
2195 	if (!err && (pass++ < MIPS_R2_EMUL_TOTAL_PASS)) {
2196 		regs->cp0_cause &= ~CAUSEF_BD;
2197 		err = get_user(inst, (u32 __user *)regs->cp0_epc);
2198 		if (!err)
2199 			goto repeat;
2200 
2201 		if (err < 0)
2202 			err = SIGSEGV;
2203 	}
2204 
2205 	if (err && (err != SIGEMT)) {
2206 		regs->regs[31] = r31;
2207 		regs->cp0_epc = epc;
2208 	}
2209 
2210 	/* Likely a MIPS R6 compatible instruction */
2211 	if (pass && (err == SIGILL))
2212 		err = 0;
2213 
2214 	return err;
2215 }
2216 
2217 #ifdef CONFIG_DEBUG_FS
2218 
2219 static int mipsr2_stats_show(struct seq_file *s, void *unused)
2220 {
2221 
2222 	seq_printf(s, "Instruction\tTotal\tBDslot\n------------------------------\n");
2223 	seq_printf(s, "movs\t\t%ld\t%ld\n",
2224 		   (unsigned long)__this_cpu_read(mipsr2emustats.movs),
2225 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.movs));
2226 	seq_printf(s, "hilo\t\t%ld\t%ld\n",
2227 		   (unsigned long)__this_cpu_read(mipsr2emustats.hilo),
2228 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.hilo));
2229 	seq_printf(s, "muls\t\t%ld\t%ld\n",
2230 		   (unsigned long)__this_cpu_read(mipsr2emustats.muls),
2231 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.muls));
2232 	seq_printf(s, "divs\t\t%ld\t%ld\n",
2233 		   (unsigned long)__this_cpu_read(mipsr2emustats.divs),
2234 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.divs));
2235 	seq_printf(s, "dsps\t\t%ld\t%ld\n",
2236 		   (unsigned long)__this_cpu_read(mipsr2emustats.dsps),
2237 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.dsps));
2238 	seq_printf(s, "bops\t\t%ld\t%ld\n",
2239 		   (unsigned long)__this_cpu_read(mipsr2emustats.bops),
2240 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.bops));
2241 	seq_printf(s, "traps\t\t%ld\t%ld\n",
2242 		   (unsigned long)__this_cpu_read(mipsr2emustats.traps),
2243 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.traps));
2244 	seq_printf(s, "fpus\t\t%ld\t%ld\n",
2245 		   (unsigned long)__this_cpu_read(mipsr2emustats.fpus),
2246 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.fpus));
2247 	seq_printf(s, "loads\t\t%ld\t%ld\n",
2248 		   (unsigned long)__this_cpu_read(mipsr2emustats.loads),
2249 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.loads));
2250 	seq_printf(s, "stores\t\t%ld\t%ld\n",
2251 		   (unsigned long)__this_cpu_read(mipsr2emustats.stores),
2252 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.stores));
2253 	seq_printf(s, "llsc\t\t%ld\t%ld\n",
2254 		   (unsigned long)__this_cpu_read(mipsr2emustats.llsc),
2255 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.llsc));
2256 	seq_printf(s, "dsemul\t\t%ld\t%ld\n",
2257 		   (unsigned long)__this_cpu_read(mipsr2emustats.dsemul),
2258 		   (unsigned long)__this_cpu_read(mipsr2bdemustats.dsemul));
2259 	seq_printf(s, "jr\t\t%ld\n",
2260 		   (unsigned long)__this_cpu_read(mipsr2bremustats.jrs));
2261 	seq_printf(s, "bltzl\t\t%ld\n",
2262 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bltzl));
2263 	seq_printf(s, "bgezl\t\t%ld\n",
2264 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgezl));
2265 	seq_printf(s, "bltzll\t\t%ld\n",
2266 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bltzll));
2267 	seq_printf(s, "bgezll\t\t%ld\n",
2268 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgezll));
2269 	seq_printf(s, "bltzal\t\t%ld\n",
2270 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bltzal));
2271 	seq_printf(s, "bgezal\t\t%ld\n",
2272 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgezal));
2273 	seq_printf(s, "beql\t\t%ld\n",
2274 		   (unsigned long)__this_cpu_read(mipsr2bremustats.beql));
2275 	seq_printf(s, "bnel\t\t%ld\n",
2276 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bnel));
2277 	seq_printf(s, "blezl\t\t%ld\n",
2278 		   (unsigned long)__this_cpu_read(mipsr2bremustats.blezl));
2279 	seq_printf(s, "bgtzl\t\t%ld\n",
2280 		   (unsigned long)__this_cpu_read(mipsr2bremustats.bgtzl));
2281 
2282 	return 0;
2283 }
2284 
2285 static int mipsr2_stats_clear_show(struct seq_file *s, void *unused)
2286 {
2287 	mipsr2_stats_show(s, unused);
2288 
2289 	__this_cpu_write((mipsr2emustats).movs, 0);
2290 	__this_cpu_write((mipsr2bdemustats).movs, 0);
2291 	__this_cpu_write((mipsr2emustats).hilo, 0);
2292 	__this_cpu_write((mipsr2bdemustats).hilo, 0);
2293 	__this_cpu_write((mipsr2emustats).muls, 0);
2294 	__this_cpu_write((mipsr2bdemustats).muls, 0);
2295 	__this_cpu_write((mipsr2emustats).divs, 0);
2296 	__this_cpu_write((mipsr2bdemustats).divs, 0);
2297 	__this_cpu_write((mipsr2emustats).dsps, 0);
2298 	__this_cpu_write((mipsr2bdemustats).dsps, 0);
2299 	__this_cpu_write((mipsr2emustats).bops, 0);
2300 	__this_cpu_write((mipsr2bdemustats).bops, 0);
2301 	__this_cpu_write((mipsr2emustats).traps, 0);
2302 	__this_cpu_write((mipsr2bdemustats).traps, 0);
2303 	__this_cpu_write((mipsr2emustats).fpus, 0);
2304 	__this_cpu_write((mipsr2bdemustats).fpus, 0);
2305 	__this_cpu_write((mipsr2emustats).loads, 0);
2306 	__this_cpu_write((mipsr2bdemustats).loads, 0);
2307 	__this_cpu_write((mipsr2emustats).stores, 0);
2308 	__this_cpu_write((mipsr2bdemustats).stores, 0);
2309 	__this_cpu_write((mipsr2emustats).llsc, 0);
2310 	__this_cpu_write((mipsr2bdemustats).llsc, 0);
2311 	__this_cpu_write((mipsr2emustats).dsemul, 0);
2312 	__this_cpu_write((mipsr2bdemustats).dsemul, 0);
2313 	__this_cpu_write((mipsr2bremustats).jrs, 0);
2314 	__this_cpu_write((mipsr2bremustats).bltzl, 0);
2315 	__this_cpu_write((mipsr2bremustats).bgezl, 0);
2316 	__this_cpu_write((mipsr2bremustats).bltzll, 0);
2317 	__this_cpu_write((mipsr2bremustats).bgezll, 0);
2318 	__this_cpu_write((mipsr2bremustats).bltzal, 0);
2319 	__this_cpu_write((mipsr2bremustats).bgezal, 0);
2320 	__this_cpu_write((mipsr2bremustats).beql, 0);
2321 	__this_cpu_write((mipsr2bremustats).bnel, 0);
2322 	__this_cpu_write((mipsr2bremustats).blezl, 0);
2323 	__this_cpu_write((mipsr2bremustats).bgtzl, 0);
2324 
2325 	return 0;
2326 }
2327 
2328 static int mipsr2_stats_open(struct inode *inode, struct file *file)
2329 {
2330 	return single_open(file, mipsr2_stats_show, inode->i_private);
2331 }
2332 
2333 static int mipsr2_stats_clear_open(struct inode *inode, struct file *file)
2334 {
2335 	return single_open(file, mipsr2_stats_clear_show, inode->i_private);
2336 }
2337 
2338 static const struct file_operations mipsr2_emul_fops = {
2339 	.open                   = mipsr2_stats_open,
2340 	.read			= seq_read,
2341 	.llseek			= seq_lseek,
2342 	.release		= single_release,
2343 };
2344 
2345 static const struct file_operations mipsr2_clear_fops = {
2346 	.open                   = mipsr2_stats_clear_open,
2347 	.read			= seq_read,
2348 	.llseek			= seq_lseek,
2349 	.release		= single_release,
2350 };
2351 
2352 
2353 static int __init mipsr2_init_debugfs(void)
2354 {
2355 	extern struct dentry	*mips_debugfs_dir;
2356 	struct dentry		*mipsr2_emul;
2357 
2358 	if (!mips_debugfs_dir)
2359 		return -ENODEV;
2360 
2361 	mipsr2_emul = debugfs_create_file("r2_emul_stats", S_IRUGO,
2362 					  mips_debugfs_dir, NULL,
2363 					  &mipsr2_emul_fops);
2364 	if (!mipsr2_emul)
2365 		return -ENOMEM;
2366 
2367 	mipsr2_emul = debugfs_create_file("r2_emul_stats_clear", S_IRUGO,
2368 					  mips_debugfs_dir, NULL,
2369 					  &mipsr2_clear_fops);
2370 	if (!mipsr2_emul)
2371 		return -ENOMEM;
2372 
2373 	return 0;
2374 }
2375 
2376 device_initcall(mipsr2_init_debugfs);
2377 
2378 #endif /* CONFIG_DEBUG_FS */
2379