xref: /linux/arch/mips/math-emu/cp1emu.c (revision d7929c1e13e3788e7cb741d75b5baec5e53eff21)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator
4  *
5  * MIPS floating point support
6  * Copyright (C) 1994-2000 Algorithmics Ltd.
7  *
8  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
9  * Copyright (C) 2000  MIPS Technologies, Inc.
10  *
11  * A complete emulator for MIPS coprocessor 1 instructions.  This is
12  * required for #float(switch) or #float(trap), where it catches all
13  * COP1 instructions via the "CoProcessor Unusable" exception.
14  *
15  * More surprisingly it is also required for #float(ieee), to help out
16  * the hardware FPU at the boundaries of the IEEE-754 representation
17  * (denormalised values, infinities, underflow, etc).  It is made
18  * quite nasty because emulation of some non-COP1 instructions is
19  * required, e.g. in branch delay slots.
20  *
21  * Note if you know that you won't have an FPU, then you'll get much
22  * better performance by compiling with -msoft-float!
23  */
24 #include <linux/sched.h>
25 #include <linux/debugfs.h>
26 #include <linux/percpu-defs.h>
27 #include <linux/perf_event.h>
28 
29 #include <asm/branch.h>
30 #include <asm/inst.h>
31 #include <asm/ptrace.h>
32 #include <asm/signal.h>
33 #include <linux/uaccess.h>
34 
35 #include <asm/cpu-info.h>
36 #include <asm/processor.h>
37 #include <asm/fpu_emulator.h>
38 #include <asm/fpu.h>
39 #include <asm/mips-r2-to-r6-emul.h>
40 
41 #include "ieee754.h"
42 
43 /* Function which emulates a floating point instruction. */
44 
45 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
46 	mips_instruction);
47 
48 static int fpux_emu(struct pt_regs *,
49 	struct mips_fpu_struct *, mips_instruction, void __user **);
50 
51 /* Control registers */
52 
53 #define FPCREG_RID	0	/* $0  = revision id */
54 #define FPCREG_FCCR	25	/* $25 = fccr */
55 #define FPCREG_FEXR	26	/* $26 = fexr */
56 #define FPCREG_FENR	28	/* $28 = fenr */
57 #define FPCREG_CSR	31	/* $31 = csr */
58 
59 /* convert condition code register number to csr bit */
60 const unsigned int fpucondbit[8] = {
61 	FPU_CSR_COND,
62 	FPU_CSR_COND1,
63 	FPU_CSR_COND2,
64 	FPU_CSR_COND3,
65 	FPU_CSR_COND4,
66 	FPU_CSR_COND5,
67 	FPU_CSR_COND6,
68 	FPU_CSR_COND7
69 };
70 
71 /* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
72 static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
73 static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
74 static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
75 static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
76 
77 /*
78  * This functions translates a 32-bit microMIPS instruction
79  * into a 32-bit MIPS32 instruction. Returns 0 on success
80  * and SIGILL otherwise.
81  */
82 static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
83 {
84 	union mips_instruction insn = *insn_ptr;
85 	union mips_instruction mips32_insn = insn;
86 	int func, fmt, op;
87 
88 	switch (insn.mm_i_format.opcode) {
89 	case mm_ldc132_op:
90 		mips32_insn.mm_i_format.opcode = ldc1_op;
91 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
92 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
93 		break;
94 	case mm_lwc132_op:
95 		mips32_insn.mm_i_format.opcode = lwc1_op;
96 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
97 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
98 		break;
99 	case mm_sdc132_op:
100 		mips32_insn.mm_i_format.opcode = sdc1_op;
101 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
102 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
103 		break;
104 	case mm_swc132_op:
105 		mips32_insn.mm_i_format.opcode = swc1_op;
106 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
107 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
108 		break;
109 	case mm_pool32i_op:
110 		/* NOTE: offset is << by 1 if in microMIPS mode. */
111 		if ((insn.mm_i_format.rt == mm_bc1f_op) ||
112 		    (insn.mm_i_format.rt == mm_bc1t_op)) {
113 			mips32_insn.fb_format.opcode = cop1_op;
114 			mips32_insn.fb_format.bc = bc_op;
115 			mips32_insn.fb_format.flag =
116 				(insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
117 		} else
118 			return SIGILL;
119 		break;
120 	case mm_pool32f_op:
121 		switch (insn.mm_fp0_format.func) {
122 		case mm_32f_01_op:
123 		case mm_32f_11_op:
124 		case mm_32f_02_op:
125 		case mm_32f_12_op:
126 		case mm_32f_41_op:
127 		case mm_32f_51_op:
128 		case mm_32f_42_op:
129 		case mm_32f_52_op:
130 			op = insn.mm_fp0_format.func;
131 			if (op == mm_32f_01_op)
132 				func = madd_s_op;
133 			else if (op == mm_32f_11_op)
134 				func = madd_d_op;
135 			else if (op == mm_32f_02_op)
136 				func = nmadd_s_op;
137 			else if (op == mm_32f_12_op)
138 				func = nmadd_d_op;
139 			else if (op == mm_32f_41_op)
140 				func = msub_s_op;
141 			else if (op == mm_32f_51_op)
142 				func = msub_d_op;
143 			else if (op == mm_32f_42_op)
144 				func = nmsub_s_op;
145 			else
146 				func = nmsub_d_op;
147 			mips32_insn.fp6_format.opcode = cop1x_op;
148 			mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
149 			mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
150 			mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
151 			mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
152 			mips32_insn.fp6_format.func = func;
153 			break;
154 		case mm_32f_10_op:
155 			func = -1;	/* Invalid */
156 			op = insn.mm_fp5_format.op & 0x7;
157 			if (op == mm_ldxc1_op)
158 				func = ldxc1_op;
159 			else if (op == mm_sdxc1_op)
160 				func = sdxc1_op;
161 			else if (op == mm_lwxc1_op)
162 				func = lwxc1_op;
163 			else if (op == mm_swxc1_op)
164 				func = swxc1_op;
165 
166 			if (func != -1) {
167 				mips32_insn.r_format.opcode = cop1x_op;
168 				mips32_insn.r_format.rs =
169 					insn.mm_fp5_format.base;
170 				mips32_insn.r_format.rt =
171 					insn.mm_fp5_format.index;
172 				mips32_insn.r_format.rd = 0;
173 				mips32_insn.r_format.re = insn.mm_fp5_format.fd;
174 				mips32_insn.r_format.func = func;
175 			} else
176 				return SIGILL;
177 			break;
178 		case mm_32f_40_op:
179 			op = -1;	/* Invalid */
180 			if (insn.mm_fp2_format.op == mm_fmovt_op)
181 				op = 1;
182 			else if (insn.mm_fp2_format.op == mm_fmovf_op)
183 				op = 0;
184 			if (op != -1) {
185 				mips32_insn.fp0_format.opcode = cop1_op;
186 				mips32_insn.fp0_format.fmt =
187 					sdps_format[insn.mm_fp2_format.fmt];
188 				mips32_insn.fp0_format.ft =
189 					(insn.mm_fp2_format.cc<<2) + op;
190 				mips32_insn.fp0_format.fs =
191 					insn.mm_fp2_format.fs;
192 				mips32_insn.fp0_format.fd =
193 					insn.mm_fp2_format.fd;
194 				mips32_insn.fp0_format.func = fmovc_op;
195 			} else
196 				return SIGILL;
197 			break;
198 		case mm_32f_60_op:
199 			func = -1;	/* Invalid */
200 			if (insn.mm_fp0_format.op == mm_fadd_op)
201 				func = fadd_op;
202 			else if (insn.mm_fp0_format.op == mm_fsub_op)
203 				func = fsub_op;
204 			else if (insn.mm_fp0_format.op == mm_fmul_op)
205 				func = fmul_op;
206 			else if (insn.mm_fp0_format.op == mm_fdiv_op)
207 				func = fdiv_op;
208 			if (func != -1) {
209 				mips32_insn.fp0_format.opcode = cop1_op;
210 				mips32_insn.fp0_format.fmt =
211 					sdps_format[insn.mm_fp0_format.fmt];
212 				mips32_insn.fp0_format.ft =
213 					insn.mm_fp0_format.ft;
214 				mips32_insn.fp0_format.fs =
215 					insn.mm_fp0_format.fs;
216 				mips32_insn.fp0_format.fd =
217 					insn.mm_fp0_format.fd;
218 				mips32_insn.fp0_format.func = func;
219 			} else
220 				return SIGILL;
221 			break;
222 		case mm_32f_70_op:
223 			func = -1;	/* Invalid */
224 			if (insn.mm_fp0_format.op == mm_fmovn_op)
225 				func = fmovn_op;
226 			else if (insn.mm_fp0_format.op == mm_fmovz_op)
227 				func = fmovz_op;
228 			if (func != -1) {
229 				mips32_insn.fp0_format.opcode = cop1_op;
230 				mips32_insn.fp0_format.fmt =
231 					sdps_format[insn.mm_fp0_format.fmt];
232 				mips32_insn.fp0_format.ft =
233 					insn.mm_fp0_format.ft;
234 				mips32_insn.fp0_format.fs =
235 					insn.mm_fp0_format.fs;
236 				mips32_insn.fp0_format.fd =
237 					insn.mm_fp0_format.fd;
238 				mips32_insn.fp0_format.func = func;
239 			} else
240 				return SIGILL;
241 			break;
242 		case mm_32f_73_op:    /* POOL32FXF */
243 			switch (insn.mm_fp1_format.op) {
244 			case mm_movf0_op:
245 			case mm_movf1_op:
246 			case mm_movt0_op:
247 			case mm_movt1_op:
248 				if ((insn.mm_fp1_format.op & 0x7f) ==
249 				    mm_movf0_op)
250 					op = 0;
251 				else
252 					op = 1;
253 				mips32_insn.r_format.opcode = spec_op;
254 				mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
255 				mips32_insn.r_format.rt =
256 					(insn.mm_fp4_format.cc << 2) + op;
257 				mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
258 				mips32_insn.r_format.re = 0;
259 				mips32_insn.r_format.func = movc_op;
260 				break;
261 			case mm_fcvtd0_op:
262 			case mm_fcvtd1_op:
263 			case mm_fcvts0_op:
264 			case mm_fcvts1_op:
265 				if ((insn.mm_fp1_format.op & 0x7f) ==
266 				    mm_fcvtd0_op) {
267 					func = fcvtd_op;
268 					fmt = swl_format[insn.mm_fp3_format.fmt];
269 				} else {
270 					func = fcvts_op;
271 					fmt = dwl_format[insn.mm_fp3_format.fmt];
272 				}
273 				mips32_insn.fp0_format.opcode = cop1_op;
274 				mips32_insn.fp0_format.fmt = fmt;
275 				mips32_insn.fp0_format.ft = 0;
276 				mips32_insn.fp0_format.fs =
277 					insn.mm_fp3_format.fs;
278 				mips32_insn.fp0_format.fd =
279 					insn.mm_fp3_format.rt;
280 				mips32_insn.fp0_format.func = func;
281 				break;
282 			case mm_fmov0_op:
283 			case mm_fmov1_op:
284 			case mm_fabs0_op:
285 			case mm_fabs1_op:
286 			case mm_fneg0_op:
287 			case mm_fneg1_op:
288 				if ((insn.mm_fp1_format.op & 0x7f) ==
289 				    mm_fmov0_op)
290 					func = fmov_op;
291 				else if ((insn.mm_fp1_format.op & 0x7f) ==
292 					 mm_fabs0_op)
293 					func = fabs_op;
294 				else
295 					func = fneg_op;
296 				mips32_insn.fp0_format.opcode = cop1_op;
297 				mips32_insn.fp0_format.fmt =
298 					sdps_format[insn.mm_fp3_format.fmt];
299 				mips32_insn.fp0_format.ft = 0;
300 				mips32_insn.fp0_format.fs =
301 					insn.mm_fp3_format.fs;
302 				mips32_insn.fp0_format.fd =
303 					insn.mm_fp3_format.rt;
304 				mips32_insn.fp0_format.func = func;
305 				break;
306 			case mm_ffloorl_op:
307 			case mm_ffloorw_op:
308 			case mm_fceill_op:
309 			case mm_fceilw_op:
310 			case mm_ftruncl_op:
311 			case mm_ftruncw_op:
312 			case mm_froundl_op:
313 			case mm_froundw_op:
314 			case mm_fcvtl_op:
315 			case mm_fcvtw_op:
316 				if (insn.mm_fp1_format.op == mm_ffloorl_op)
317 					func = ffloorl_op;
318 				else if (insn.mm_fp1_format.op == mm_ffloorw_op)
319 					func = ffloor_op;
320 				else if (insn.mm_fp1_format.op == mm_fceill_op)
321 					func = fceill_op;
322 				else if (insn.mm_fp1_format.op == mm_fceilw_op)
323 					func = fceil_op;
324 				else if (insn.mm_fp1_format.op == mm_ftruncl_op)
325 					func = ftruncl_op;
326 				else if (insn.mm_fp1_format.op == mm_ftruncw_op)
327 					func = ftrunc_op;
328 				else if (insn.mm_fp1_format.op == mm_froundl_op)
329 					func = froundl_op;
330 				else if (insn.mm_fp1_format.op == mm_froundw_op)
331 					func = fround_op;
332 				else if (insn.mm_fp1_format.op == mm_fcvtl_op)
333 					func = fcvtl_op;
334 				else
335 					func = fcvtw_op;
336 				mips32_insn.fp0_format.opcode = cop1_op;
337 				mips32_insn.fp0_format.fmt =
338 					sd_format[insn.mm_fp1_format.fmt];
339 				mips32_insn.fp0_format.ft = 0;
340 				mips32_insn.fp0_format.fs =
341 					insn.mm_fp1_format.fs;
342 				mips32_insn.fp0_format.fd =
343 					insn.mm_fp1_format.rt;
344 				mips32_insn.fp0_format.func = func;
345 				break;
346 			case mm_frsqrt_op:
347 			case mm_fsqrt_op:
348 			case mm_frecip_op:
349 				if (insn.mm_fp1_format.op == mm_frsqrt_op)
350 					func = frsqrt_op;
351 				else if (insn.mm_fp1_format.op == mm_fsqrt_op)
352 					func = fsqrt_op;
353 				else
354 					func = frecip_op;
355 				mips32_insn.fp0_format.opcode = cop1_op;
356 				mips32_insn.fp0_format.fmt =
357 					sdps_format[insn.mm_fp1_format.fmt];
358 				mips32_insn.fp0_format.ft = 0;
359 				mips32_insn.fp0_format.fs =
360 					insn.mm_fp1_format.fs;
361 				mips32_insn.fp0_format.fd =
362 					insn.mm_fp1_format.rt;
363 				mips32_insn.fp0_format.func = func;
364 				break;
365 			case mm_mfc1_op:
366 			case mm_mtc1_op:
367 			case mm_cfc1_op:
368 			case mm_ctc1_op:
369 			case mm_mfhc1_op:
370 			case mm_mthc1_op:
371 				if (insn.mm_fp1_format.op == mm_mfc1_op)
372 					op = mfc_op;
373 				else if (insn.mm_fp1_format.op == mm_mtc1_op)
374 					op = mtc_op;
375 				else if (insn.mm_fp1_format.op == mm_cfc1_op)
376 					op = cfc_op;
377 				else if (insn.mm_fp1_format.op == mm_ctc1_op)
378 					op = ctc_op;
379 				else if (insn.mm_fp1_format.op == mm_mfhc1_op)
380 					op = mfhc_op;
381 				else
382 					op = mthc_op;
383 				mips32_insn.fp1_format.opcode = cop1_op;
384 				mips32_insn.fp1_format.op = op;
385 				mips32_insn.fp1_format.rt =
386 					insn.mm_fp1_format.rt;
387 				mips32_insn.fp1_format.fs =
388 					insn.mm_fp1_format.fs;
389 				mips32_insn.fp1_format.fd = 0;
390 				mips32_insn.fp1_format.func = 0;
391 				break;
392 			default:
393 				return SIGILL;
394 			}
395 			break;
396 		case mm_32f_74_op:	/* c.cond.fmt */
397 			mips32_insn.fp0_format.opcode = cop1_op;
398 			mips32_insn.fp0_format.fmt =
399 				sdps_format[insn.mm_fp4_format.fmt];
400 			mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
401 			mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
402 			mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
403 			mips32_insn.fp0_format.func =
404 				insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
405 			break;
406 		default:
407 			return SIGILL;
408 		}
409 		break;
410 	default:
411 		return SIGILL;
412 	}
413 
414 	*insn_ptr = mips32_insn;
415 	return 0;
416 }
417 
418 /*
419  * Redundant with logic already in kernel/branch.c,
420  * embedded in compute_return_epc.  At some point,
421  * a single subroutine should be used across both
422  * modules.
423  */
424 int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
425 		  unsigned long *contpc)
426 {
427 	union mips_instruction insn = (union mips_instruction)dec_insn.insn;
428 	unsigned int fcr31;
429 	unsigned int bit = 0;
430 	unsigned int bit0;
431 	union fpureg *fpr;
432 
433 	switch (insn.i_format.opcode) {
434 	case spec_op:
435 		switch (insn.r_format.func) {
436 		case jalr_op:
437 			if (insn.r_format.rd != 0) {
438 				regs->regs[insn.r_format.rd] =
439 					regs->cp0_epc + dec_insn.pc_inc +
440 					dec_insn.next_pc_inc;
441 			}
442 			/* fall through */
443 		case jr_op:
444 			/* For R6, JR already emulated in jalr_op */
445 			if (NO_R6EMU && insn.r_format.func == jr_op)
446 				break;
447 			*contpc = regs->regs[insn.r_format.rs];
448 			return 1;
449 		}
450 		break;
451 	case bcond_op:
452 		switch (insn.i_format.rt) {
453 		case bltzal_op:
454 		case bltzall_op:
455 			if (NO_R6EMU && (insn.i_format.rs ||
456 			    insn.i_format.rt == bltzall_op))
457 				break;
458 
459 			regs->regs[31] = regs->cp0_epc +
460 				dec_insn.pc_inc +
461 				dec_insn.next_pc_inc;
462 			/* fall through */
463 		case bltzl_op:
464 			if (NO_R6EMU)
465 				break;
466 			/* fall through */
467 		case bltz_op:
468 			if ((long)regs->regs[insn.i_format.rs] < 0)
469 				*contpc = regs->cp0_epc +
470 					dec_insn.pc_inc +
471 					(insn.i_format.simmediate << 2);
472 			else
473 				*contpc = regs->cp0_epc +
474 					dec_insn.pc_inc +
475 					dec_insn.next_pc_inc;
476 			return 1;
477 		case bgezal_op:
478 		case bgezall_op:
479 			if (NO_R6EMU && (insn.i_format.rs ||
480 			    insn.i_format.rt == bgezall_op))
481 				break;
482 
483 			regs->regs[31] = regs->cp0_epc +
484 				dec_insn.pc_inc +
485 				dec_insn.next_pc_inc;
486 			/* fall through */
487 		case bgezl_op:
488 			if (NO_R6EMU)
489 				break;
490 			/* fall through */
491 		case bgez_op:
492 			if ((long)regs->regs[insn.i_format.rs] >= 0)
493 				*contpc = regs->cp0_epc +
494 					dec_insn.pc_inc +
495 					(insn.i_format.simmediate << 2);
496 			else
497 				*contpc = regs->cp0_epc +
498 					dec_insn.pc_inc +
499 					dec_insn.next_pc_inc;
500 			return 1;
501 		}
502 		break;
503 	case jalx_op:
504 		set_isa16_mode(bit);
505 		/* fall through */
506 	case jal_op:
507 		regs->regs[31] = regs->cp0_epc +
508 			dec_insn.pc_inc +
509 			dec_insn.next_pc_inc;
510 		/* fall through */
511 	case j_op:
512 		*contpc = regs->cp0_epc + dec_insn.pc_inc;
513 		*contpc >>= 28;
514 		*contpc <<= 28;
515 		*contpc |= (insn.j_format.target << 2);
516 		/* Set microMIPS mode bit: XOR for jalx. */
517 		*contpc ^= bit;
518 		return 1;
519 	case beql_op:
520 		if (NO_R6EMU)
521 			break;
522 		/* fall through */
523 	case beq_op:
524 		if (regs->regs[insn.i_format.rs] ==
525 		    regs->regs[insn.i_format.rt])
526 			*contpc = regs->cp0_epc +
527 				dec_insn.pc_inc +
528 				(insn.i_format.simmediate << 2);
529 		else
530 			*contpc = regs->cp0_epc +
531 				dec_insn.pc_inc +
532 				dec_insn.next_pc_inc;
533 		return 1;
534 	case bnel_op:
535 		if (NO_R6EMU)
536 			break;
537 		/* fall through */
538 	case bne_op:
539 		if (regs->regs[insn.i_format.rs] !=
540 		    regs->regs[insn.i_format.rt])
541 			*contpc = regs->cp0_epc +
542 				dec_insn.pc_inc +
543 				(insn.i_format.simmediate << 2);
544 		else
545 			*contpc = regs->cp0_epc +
546 				dec_insn.pc_inc +
547 				dec_insn.next_pc_inc;
548 		return 1;
549 	case blezl_op:
550 		if (!insn.i_format.rt && NO_R6EMU)
551 			break;
552 		/* fall through */
553 	case blez_op:
554 
555 		/*
556 		 * Compact branches for R6 for the
557 		 * blez and blezl opcodes.
558 		 * BLEZ  | rs = 0 | rt != 0  == BLEZALC
559 		 * BLEZ  | rs = rt != 0      == BGEZALC
560 		 * BLEZ  | rs != 0 | rt != 0 == BGEUC
561 		 * BLEZL | rs = 0 | rt != 0  == BLEZC
562 		 * BLEZL | rs = rt != 0      == BGEZC
563 		 * BLEZL | rs != 0 | rt != 0 == BGEC
564 		 *
565 		 * For real BLEZ{,L}, rt is always 0.
566 		 */
567 		if (cpu_has_mips_r6 && insn.i_format.rt) {
568 			if ((insn.i_format.opcode == blez_op) &&
569 			    ((!insn.i_format.rs && insn.i_format.rt) ||
570 			     (insn.i_format.rs == insn.i_format.rt)))
571 				regs->regs[31] = regs->cp0_epc +
572 					dec_insn.pc_inc;
573 			*contpc = regs->cp0_epc + dec_insn.pc_inc +
574 				dec_insn.next_pc_inc;
575 
576 			return 1;
577 		}
578 		if ((long)regs->regs[insn.i_format.rs] <= 0)
579 			*contpc = regs->cp0_epc +
580 				dec_insn.pc_inc +
581 				(insn.i_format.simmediate << 2);
582 		else
583 			*contpc = regs->cp0_epc +
584 				dec_insn.pc_inc +
585 				dec_insn.next_pc_inc;
586 		return 1;
587 	case bgtzl_op:
588 		if (!insn.i_format.rt && NO_R6EMU)
589 			break;
590 		/* fall through */
591 	case bgtz_op:
592 		/*
593 		 * Compact branches for R6 for the
594 		 * bgtz and bgtzl opcodes.
595 		 * BGTZ  | rs = 0 | rt != 0  == BGTZALC
596 		 * BGTZ  | rs = rt != 0      == BLTZALC
597 		 * BGTZ  | rs != 0 | rt != 0 == BLTUC
598 		 * BGTZL | rs = 0 | rt != 0  == BGTZC
599 		 * BGTZL | rs = rt != 0      == BLTZC
600 		 * BGTZL | rs != 0 | rt != 0 == BLTC
601 		 *
602 		 * *ZALC varint for BGTZ &&& rt != 0
603 		 * For real GTZ{,L}, rt is always 0.
604 		 */
605 		if (cpu_has_mips_r6 && insn.i_format.rt) {
606 			if ((insn.i_format.opcode == blez_op) &&
607 			    ((!insn.i_format.rs && insn.i_format.rt) ||
608 			     (insn.i_format.rs == insn.i_format.rt)))
609 				regs->regs[31] = regs->cp0_epc +
610 					dec_insn.pc_inc;
611 			*contpc = regs->cp0_epc + dec_insn.pc_inc +
612 				dec_insn.next_pc_inc;
613 
614 			return 1;
615 		}
616 
617 		if ((long)regs->regs[insn.i_format.rs] > 0)
618 			*contpc = regs->cp0_epc +
619 				dec_insn.pc_inc +
620 				(insn.i_format.simmediate << 2);
621 		else
622 			*contpc = regs->cp0_epc +
623 				dec_insn.pc_inc +
624 				dec_insn.next_pc_inc;
625 		return 1;
626 	case pop10_op:
627 	case pop30_op:
628 		if (!cpu_has_mips_r6)
629 			break;
630 		if (insn.i_format.rt && !insn.i_format.rs)
631 			regs->regs[31] = regs->cp0_epc + 4;
632 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
633 			dec_insn.next_pc_inc;
634 
635 		return 1;
636 #ifdef CONFIG_CPU_CAVIUM_OCTEON
637 	case lwc2_op: /* This is bbit0 on Octeon */
638 		if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
639 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
640 		else
641 			*contpc = regs->cp0_epc + 8;
642 		return 1;
643 	case ldc2_op: /* This is bbit032 on Octeon */
644 		if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
645 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
646 		else
647 			*contpc = regs->cp0_epc + 8;
648 		return 1;
649 	case swc2_op: /* This is bbit1 on Octeon */
650 		if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
651 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
652 		else
653 			*contpc = regs->cp0_epc + 8;
654 		return 1;
655 	case sdc2_op: /* This is bbit132 on Octeon */
656 		if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
657 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
658 		else
659 			*contpc = regs->cp0_epc + 8;
660 		return 1;
661 #else
662 	case bc6_op:
663 		/*
664 		 * Only valid for MIPS R6 but we can still end up
665 		 * here from a broken userland so just tell emulator
666 		 * this is not a branch and let it break later on.
667 		 */
668 		if  (!cpu_has_mips_r6)
669 			break;
670 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
671 			dec_insn.next_pc_inc;
672 
673 		return 1;
674 	case balc6_op:
675 		if (!cpu_has_mips_r6)
676 			break;
677 		regs->regs[31] = regs->cp0_epc + 4;
678 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
679 			dec_insn.next_pc_inc;
680 
681 		return 1;
682 	case pop66_op:
683 		if (!cpu_has_mips_r6)
684 			break;
685 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
686 			dec_insn.next_pc_inc;
687 
688 		return 1;
689 	case pop76_op:
690 		if (!cpu_has_mips_r6)
691 			break;
692 		if (!insn.i_format.rs)
693 			regs->regs[31] = regs->cp0_epc + 4;
694 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
695 			dec_insn.next_pc_inc;
696 
697 		return 1;
698 #endif
699 	case cop0_op:
700 	case cop1_op:
701 		/* Need to check for R6 bc1nez and bc1eqz branches */
702 		if (cpu_has_mips_r6 &&
703 		    ((insn.i_format.rs == bc1eqz_op) ||
704 		     (insn.i_format.rs == bc1nez_op))) {
705 			bit = 0;
706 			fpr = &current->thread.fpu.fpr[insn.i_format.rt];
707 			bit0 = get_fpr32(fpr, 0) & 0x1;
708 			switch (insn.i_format.rs) {
709 			case bc1eqz_op:
710 				bit = bit0 == 0;
711 				break;
712 			case bc1nez_op:
713 				bit = bit0 != 0;
714 				break;
715 			}
716 			if (bit)
717 				*contpc = regs->cp0_epc +
718 					dec_insn.pc_inc +
719 					(insn.i_format.simmediate << 2);
720 			else
721 				*contpc = regs->cp0_epc +
722 					dec_insn.pc_inc +
723 					dec_insn.next_pc_inc;
724 
725 			return 1;
726 		}
727 		/* R2/R6 compatible cop1 instruction */
728 		/* fall through */
729 	case cop2_op:
730 	case cop1x_op:
731 		if (insn.i_format.rs == bc_op) {
732 			preempt_disable();
733 			if (is_fpu_owner())
734 			        fcr31 = read_32bit_cp1_register(CP1_STATUS);
735 			else
736 				fcr31 = current->thread.fpu.fcr31;
737 			preempt_enable();
738 
739 			bit = (insn.i_format.rt >> 2);
740 			bit += (bit != 0);
741 			bit += 23;
742 			switch (insn.i_format.rt & 3) {
743 			case 0:	/* bc1f */
744 			case 2:	/* bc1fl */
745 				if (~fcr31 & (1 << bit))
746 					*contpc = regs->cp0_epc +
747 						dec_insn.pc_inc +
748 						(insn.i_format.simmediate << 2);
749 				else
750 					*contpc = regs->cp0_epc +
751 						dec_insn.pc_inc +
752 						dec_insn.next_pc_inc;
753 				return 1;
754 			case 1:	/* bc1t */
755 			case 3:	/* bc1tl */
756 				if (fcr31 & (1 << bit))
757 					*contpc = regs->cp0_epc +
758 						dec_insn.pc_inc +
759 						(insn.i_format.simmediate << 2);
760 				else
761 					*contpc = regs->cp0_epc +
762 						dec_insn.pc_inc +
763 						dec_insn.next_pc_inc;
764 				return 1;
765 			}
766 		}
767 		break;
768 	}
769 	return 0;
770 }
771 
772 /*
773  * In the Linux kernel, we support selection of FPR format on the
774  * basis of the Status.FR bit.	If an FPU is not present, the FR bit
775  * is hardwired to zero, which would imply a 32-bit FPU even for
776  * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
777  * FPU emu is slow and bulky and optimizing this function offers fairly
778  * sizeable benefits so we try to be clever and make this function return
779  * a constant whenever possible, that is on 64-bit kernels without O32
780  * compatibility enabled and on 32-bit without 64-bit FPU support.
781  */
782 static inline int cop1_64bit(struct pt_regs *xcp)
783 {
784 	if (IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_MIPS32_O32))
785 		return 1;
786 	else if (IS_ENABLED(CONFIG_32BIT) &&
787 		 !IS_ENABLED(CONFIG_MIPS_O32_FP64_SUPPORT))
788 		return 0;
789 
790 	return !test_thread_flag(TIF_32BIT_FPREGS);
791 }
792 
793 static inline bool hybrid_fprs(void)
794 {
795 	return test_thread_flag(TIF_HYBRID_FPREGS);
796 }
797 
798 #define SIFROMREG(si, x)						\
799 do {									\
800 	if (cop1_64bit(xcp) && !hybrid_fprs())				\
801 		(si) = (int)get_fpr32(&ctx->fpr[x], 0);			\
802 	else								\
803 		(si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1);	\
804 } while (0)
805 
806 #define SITOREG(si, x)							\
807 do {									\
808 	if (cop1_64bit(xcp) && !hybrid_fprs()) {			\
809 		unsigned int i;						\
810 		set_fpr32(&ctx->fpr[x], 0, si);				\
811 		for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)	\
812 			set_fpr32(&ctx->fpr[x], i, 0);			\
813 	} else {							\
814 		set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si);		\
815 	}								\
816 } while (0)
817 
818 #define SIFROMHREG(si, x)	((si) = (int)get_fpr32(&ctx->fpr[x], 1))
819 
820 #define SITOHREG(si, x)							\
821 do {									\
822 	unsigned int i;							\
823 	set_fpr32(&ctx->fpr[x], 1, si);					\
824 	for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)		\
825 		set_fpr32(&ctx->fpr[x], i, 0);				\
826 } while (0)
827 
828 #define DIFROMREG(di, x)						\
829 	((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) ^ 1)], 0))
830 
831 #define DITOREG(di, x)							\
832 do {									\
833 	unsigned int fpr, i;						\
834 	fpr = (x) & ~(cop1_64bit(xcp) ^ 1);				\
835 	set_fpr64(&ctx->fpr[fpr], 0, di);				\
836 	for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++)		\
837 		set_fpr64(&ctx->fpr[fpr], i, 0);			\
838 } while (0)
839 
840 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
841 #define SPTOREG(sp, x)	SITOREG((sp).bits, x)
842 #define DPFROMREG(dp, x)	DIFROMREG((dp).bits, x)
843 #define DPTOREG(dp, x)	DITOREG((dp).bits, x)
844 
845 /*
846  * Emulate a CFC1 instruction.
847  */
848 static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
849 			    mips_instruction ir)
850 {
851 	u32 fcr31 = ctx->fcr31;
852 	u32 value = 0;
853 
854 	switch (MIPSInst_RD(ir)) {
855 	case FPCREG_CSR:
856 		value = fcr31;
857 		pr_debug("%p gpr[%d]<-csr=%08x\n",
858 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
859 		break;
860 
861 	case FPCREG_FENR:
862 		if (!cpu_has_mips_r)
863 			break;
864 		value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
865 			MIPS_FENR_FS;
866 		value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM);
867 		pr_debug("%p gpr[%d]<-enr=%08x\n",
868 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
869 		break;
870 
871 	case FPCREG_FEXR:
872 		if (!cpu_has_mips_r)
873 			break;
874 		value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
875 		pr_debug("%p gpr[%d]<-exr=%08x\n",
876 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
877 		break;
878 
879 	case FPCREG_FCCR:
880 		if (!cpu_has_mips_r)
881 			break;
882 		value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
883 			MIPS_FCCR_COND0;
884 		value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
885 			 (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0);
886 		pr_debug("%p gpr[%d]<-ccr=%08x\n",
887 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
888 		break;
889 
890 	case FPCREG_RID:
891 		value = boot_cpu_data.fpu_id;
892 		break;
893 
894 	default:
895 		break;
896 	}
897 
898 	if (MIPSInst_RT(ir))
899 		xcp->regs[MIPSInst_RT(ir)] = value;
900 }
901 
902 /*
903  * Emulate a CTC1 instruction.
904  */
905 static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
906 			    mips_instruction ir)
907 {
908 	u32 fcr31 = ctx->fcr31;
909 	u32 value;
910 	u32 mask;
911 
912 	if (MIPSInst_RT(ir) == 0)
913 		value = 0;
914 	else
915 		value = xcp->regs[MIPSInst_RT(ir)];
916 
917 	switch (MIPSInst_RD(ir)) {
918 	case FPCREG_CSR:
919 		pr_debug("%p gpr[%d]->csr=%08x\n",
920 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
921 
922 		/* Preserve read-only bits.  */
923 		mask = boot_cpu_data.fpu_msk31;
924 		fcr31 = (value & ~mask) | (fcr31 & mask);
925 		break;
926 
927 	case FPCREG_FENR:
928 		if (!cpu_has_mips_r)
929 			break;
930 		pr_debug("%p gpr[%d]->enr=%08x\n",
931 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
932 		fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM);
933 		fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
934 			 FPU_CSR_FS;
935 		fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM);
936 		break;
937 
938 	case FPCREG_FEXR:
939 		if (!cpu_has_mips_r)
940 			break;
941 		pr_debug("%p gpr[%d]->exr=%08x\n",
942 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
943 		fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S);
944 		fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
945 		break;
946 
947 	case FPCREG_FCCR:
948 		if (!cpu_has_mips_r)
949 			break;
950 		pr_debug("%p gpr[%d]->ccr=%08x\n",
951 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
952 		fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND);
953 		fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
954 			 FPU_CSR_COND;
955 		fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
956 			 FPU_CSR_CONDX;
957 		break;
958 
959 	default:
960 		break;
961 	}
962 
963 	ctx->fcr31 = fcr31;
964 }
965 
966 /*
967  * Emulate the single floating point instruction pointed at by EPC.
968  * Two instructions if the instruction is in a branch delay slot.
969  */
970 
971 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
972 		struct mm_decoded_insn dec_insn, void __user **fault_addr)
973 {
974 	unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
975 	unsigned int cond, cbit, bit0;
976 	mips_instruction ir;
977 	int likely, pc_inc;
978 	union fpureg *fpr;
979 	u32 __user *wva;
980 	u64 __user *dva;
981 	u32 wval;
982 	u64 dval;
983 	int sig;
984 
985 	/*
986 	 * These are giving gcc a gentle hint about what to expect in
987 	 * dec_inst in order to do better optimization.
988 	 */
989 	if (!cpu_has_mmips && dec_insn.micro_mips_mode)
990 		unreachable();
991 
992 	/* XXX NEC Vr54xx bug workaround */
993 	if (delay_slot(xcp)) {
994 		if (dec_insn.micro_mips_mode) {
995 			if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
996 				clear_delay_slot(xcp);
997 		} else {
998 			if (!isBranchInstr(xcp, dec_insn, &contpc))
999 				clear_delay_slot(xcp);
1000 		}
1001 	}
1002 
1003 	if (delay_slot(xcp)) {
1004 		/*
1005 		 * The instruction to be emulated is in a branch delay slot
1006 		 * which means that we have to	emulate the branch instruction
1007 		 * BEFORE we do the cop1 instruction.
1008 		 *
1009 		 * This branch could be a COP1 branch, but in that case we
1010 		 * would have had a trap for that instruction, and would not
1011 		 * come through this route.
1012 		 *
1013 		 * Linux MIPS branch emulator operates on context, updating the
1014 		 * cp0_epc.
1015 		 */
1016 		ir = dec_insn.next_insn;  /* process delay slot instr */
1017 		pc_inc = dec_insn.next_pc_inc;
1018 	} else {
1019 		ir = dec_insn.insn;       /* process current instr */
1020 		pc_inc = dec_insn.pc_inc;
1021 	}
1022 
1023 	/*
1024 	 * Since microMIPS FPU instructios are a subset of MIPS32 FPU
1025 	 * instructions, we want to convert microMIPS FPU instructions
1026 	 * into MIPS32 instructions so that we could reuse all of the
1027 	 * FPU emulation code.
1028 	 *
1029 	 * NOTE: We cannot do this for branch instructions since they
1030 	 *       are not a subset. Example: Cannot emulate a 16-bit
1031 	 *       aligned target address with a MIPS32 instruction.
1032 	 */
1033 	if (dec_insn.micro_mips_mode) {
1034 		/*
1035 		 * If next instruction is a 16-bit instruction, then it
1036 		 * it cannot be a FPU instruction. This could happen
1037 		 * since we can be called for non-FPU instructions.
1038 		 */
1039 		if ((pc_inc == 2) ||
1040 			(microMIPS32_to_MIPS32((union mips_instruction *)&ir)
1041 			 == SIGILL))
1042 			return SIGILL;
1043 	}
1044 
1045 emul:
1046 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
1047 	MIPS_FPU_EMU_INC_STATS(emulated);
1048 	switch (MIPSInst_OPCODE(ir)) {
1049 	case ldc1_op:
1050 		dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1051 				     MIPSInst_SIMM(ir));
1052 		MIPS_FPU_EMU_INC_STATS(loads);
1053 
1054 		if (!access_ok(dva, sizeof(u64))) {
1055 			MIPS_FPU_EMU_INC_STATS(errors);
1056 			*fault_addr = dva;
1057 			return SIGBUS;
1058 		}
1059 		if (__get_user(dval, dva)) {
1060 			MIPS_FPU_EMU_INC_STATS(errors);
1061 			*fault_addr = dva;
1062 			return SIGSEGV;
1063 		}
1064 		DITOREG(dval, MIPSInst_RT(ir));
1065 		break;
1066 
1067 	case sdc1_op:
1068 		dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1069 				      MIPSInst_SIMM(ir));
1070 		MIPS_FPU_EMU_INC_STATS(stores);
1071 		DIFROMREG(dval, MIPSInst_RT(ir));
1072 		if (!access_ok(dva, sizeof(u64))) {
1073 			MIPS_FPU_EMU_INC_STATS(errors);
1074 			*fault_addr = dva;
1075 			return SIGBUS;
1076 		}
1077 		if (__put_user(dval, dva)) {
1078 			MIPS_FPU_EMU_INC_STATS(errors);
1079 			*fault_addr = dva;
1080 			return SIGSEGV;
1081 		}
1082 		break;
1083 
1084 	case lwc1_op:
1085 		wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1086 				      MIPSInst_SIMM(ir));
1087 		MIPS_FPU_EMU_INC_STATS(loads);
1088 		if (!access_ok(wva, sizeof(u32))) {
1089 			MIPS_FPU_EMU_INC_STATS(errors);
1090 			*fault_addr = wva;
1091 			return SIGBUS;
1092 		}
1093 		if (__get_user(wval, wva)) {
1094 			MIPS_FPU_EMU_INC_STATS(errors);
1095 			*fault_addr = wva;
1096 			return SIGSEGV;
1097 		}
1098 		SITOREG(wval, MIPSInst_RT(ir));
1099 		break;
1100 
1101 	case swc1_op:
1102 		wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1103 				      MIPSInst_SIMM(ir));
1104 		MIPS_FPU_EMU_INC_STATS(stores);
1105 		SIFROMREG(wval, MIPSInst_RT(ir));
1106 		if (!access_ok(wva, sizeof(u32))) {
1107 			MIPS_FPU_EMU_INC_STATS(errors);
1108 			*fault_addr = wva;
1109 			return SIGBUS;
1110 		}
1111 		if (__put_user(wval, wva)) {
1112 			MIPS_FPU_EMU_INC_STATS(errors);
1113 			*fault_addr = wva;
1114 			return SIGSEGV;
1115 		}
1116 		break;
1117 
1118 	case cop1_op:
1119 		switch (MIPSInst_RS(ir)) {
1120 		case dmfc_op:
1121 			if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1122 				return SIGILL;
1123 
1124 			/* copregister fs -> gpr[rt] */
1125 			if (MIPSInst_RT(ir) != 0) {
1126 				DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1127 					MIPSInst_RD(ir));
1128 			}
1129 			break;
1130 
1131 		case dmtc_op:
1132 			if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1133 				return SIGILL;
1134 
1135 			/* copregister fs <- rt */
1136 			DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1137 			break;
1138 
1139 		case mfhc_op:
1140 			if (!cpu_has_mips_r2_r6)
1141 				return SIGILL;
1142 
1143 			/* copregister rd -> gpr[rt] */
1144 			if (MIPSInst_RT(ir) != 0) {
1145 				SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
1146 					MIPSInst_RD(ir));
1147 			}
1148 			break;
1149 
1150 		case mthc_op:
1151 			if (!cpu_has_mips_r2_r6)
1152 				return SIGILL;
1153 
1154 			/* copregister rd <- gpr[rt] */
1155 			SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1156 			break;
1157 
1158 		case mfc_op:
1159 			/* copregister rd -> gpr[rt] */
1160 			if (MIPSInst_RT(ir) != 0) {
1161 				SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1162 					MIPSInst_RD(ir));
1163 			}
1164 			break;
1165 
1166 		case mtc_op:
1167 			/* copregister rd <- rt */
1168 			SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1169 			break;
1170 
1171 		case cfc_op:
1172 			/* cop control register rd -> gpr[rt] */
1173 			cop1_cfc(xcp, ctx, ir);
1174 			break;
1175 
1176 		case ctc_op:
1177 			/* copregister rd <- rt */
1178 			cop1_ctc(xcp, ctx, ir);
1179 			if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1180 				return SIGFPE;
1181 			}
1182 			break;
1183 
1184 		case bc1eqz_op:
1185 		case bc1nez_op:
1186 			if (!cpu_has_mips_r6 || delay_slot(xcp))
1187 				return SIGILL;
1188 
1189 			likely = 0;
1190 			cond = 0;
1191 			fpr = &current->thread.fpu.fpr[MIPSInst_RT(ir)];
1192 			bit0 = get_fpr32(fpr, 0) & 0x1;
1193 			switch (MIPSInst_RS(ir)) {
1194 			case bc1eqz_op:
1195 				MIPS_FPU_EMU_INC_STATS(bc1eqz);
1196 				cond = bit0 == 0;
1197 				break;
1198 			case bc1nez_op:
1199 				MIPS_FPU_EMU_INC_STATS(bc1nez);
1200 				cond = bit0 != 0;
1201 				break;
1202 			}
1203 			goto branch_common;
1204 
1205 		case bc_op:
1206 			if (delay_slot(xcp))
1207 				return SIGILL;
1208 
1209 			if (cpu_has_mips_4_5_r)
1210 				cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
1211 			else
1212 				cbit = FPU_CSR_COND;
1213 			cond = ctx->fcr31 & cbit;
1214 
1215 			likely = 0;
1216 			switch (MIPSInst_RT(ir) & 3) {
1217 			case bcfl_op:
1218 				if (cpu_has_mips_2_3_4_5_r)
1219 					likely = 1;
1220 				/* fall through */
1221 			case bcf_op:
1222 				cond = !cond;
1223 				break;
1224 			case bctl_op:
1225 				if (cpu_has_mips_2_3_4_5_r)
1226 					likely = 1;
1227 				/* fall through */
1228 			case bct_op:
1229 				break;
1230 			}
1231 branch_common:
1232 			MIPS_FPU_EMU_INC_STATS(branches);
1233 			set_delay_slot(xcp);
1234 			if (cond) {
1235 				/*
1236 				 * Branch taken: emulate dslot instruction
1237 				 */
1238 				unsigned long bcpc;
1239 
1240 				/*
1241 				 * Remember EPC at the branch to point back
1242 				 * at so that any delay-slot instruction
1243 				 * signal is not silently ignored.
1244 				 */
1245 				bcpc = xcp->cp0_epc;
1246 				xcp->cp0_epc += dec_insn.pc_inc;
1247 
1248 				contpc = MIPSInst_SIMM(ir);
1249 				ir = dec_insn.next_insn;
1250 				if (dec_insn.micro_mips_mode) {
1251 					contpc = (xcp->cp0_epc + (contpc << 1));
1252 
1253 					/* If 16-bit instruction, not FPU. */
1254 					if ((dec_insn.next_pc_inc == 2) ||
1255 						(microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
1256 
1257 						/*
1258 						 * Since this instruction will
1259 						 * be put on the stack with
1260 						 * 32-bit words, get around
1261 						 * this problem by putting a
1262 						 * NOP16 as the second one.
1263 						 */
1264 						if (dec_insn.next_pc_inc == 2)
1265 							ir = (ir & (~0xffff)) | MM_NOP16;
1266 
1267 						/*
1268 						 * Single step the non-CP1
1269 						 * instruction in the dslot.
1270 						 */
1271 						sig = mips_dsemul(xcp, ir,
1272 								  bcpc, contpc);
1273 						if (sig < 0)
1274 							break;
1275 						if (sig)
1276 							xcp->cp0_epc = bcpc;
1277 						/*
1278 						 * SIGILL forces out of
1279 						 * the emulation loop.
1280 						 */
1281 						return sig ? sig : SIGILL;
1282 					}
1283 				} else
1284 					contpc = (xcp->cp0_epc + (contpc << 2));
1285 
1286 				switch (MIPSInst_OPCODE(ir)) {
1287 				case lwc1_op:
1288 				case swc1_op:
1289 					goto emul;
1290 
1291 				case ldc1_op:
1292 				case sdc1_op:
1293 					if (cpu_has_mips_2_3_4_5_r)
1294 						goto emul;
1295 
1296 					goto bc_sigill;
1297 
1298 				case cop1_op:
1299 					goto emul;
1300 
1301 				case cop1x_op:
1302 					if (cpu_has_mips_4_5_64_r2_r6)
1303 						/* its one of ours */
1304 						goto emul;
1305 
1306 					goto bc_sigill;
1307 
1308 				case spec_op:
1309 					switch (MIPSInst_FUNC(ir)) {
1310 					case movc_op:
1311 						if (cpu_has_mips_4_5_r)
1312 							goto emul;
1313 
1314 						goto bc_sigill;
1315 					}
1316 					break;
1317 
1318 				bc_sigill:
1319 					xcp->cp0_epc = bcpc;
1320 					return SIGILL;
1321 				}
1322 
1323 				/*
1324 				 * Single step the non-cp1
1325 				 * instruction in the dslot
1326 				 */
1327 				sig = mips_dsemul(xcp, ir, bcpc, contpc);
1328 				if (sig < 0)
1329 					break;
1330 				if (sig)
1331 					xcp->cp0_epc = bcpc;
1332 				/* SIGILL forces out of the emulation loop.  */
1333 				return sig ? sig : SIGILL;
1334 			} else if (likely) {	/* branch not taken */
1335 				/*
1336 				 * branch likely nullifies
1337 				 * dslot if not taken
1338 				 */
1339 				xcp->cp0_epc += dec_insn.pc_inc;
1340 				contpc += dec_insn.pc_inc;
1341 				/*
1342 				 * else continue & execute
1343 				 * dslot as normal insn
1344 				 */
1345 			}
1346 			break;
1347 
1348 		default:
1349 			if (!(MIPSInst_RS(ir) & 0x10))
1350 				return SIGILL;
1351 
1352 			/* a real fpu computation instruction */
1353 			sig = fpu_emu(xcp, ctx, ir);
1354 			if (sig)
1355 				return sig;
1356 		}
1357 		break;
1358 
1359 	case cop1x_op:
1360 		if (!cpu_has_mips_4_5_64_r2_r6)
1361 			return SIGILL;
1362 
1363 		sig = fpux_emu(xcp, ctx, ir, fault_addr);
1364 		if (sig)
1365 			return sig;
1366 		break;
1367 
1368 	case spec_op:
1369 		if (!cpu_has_mips_4_5_r)
1370 			return SIGILL;
1371 
1372 		if (MIPSInst_FUNC(ir) != movc_op)
1373 			return SIGILL;
1374 		cond = fpucondbit[MIPSInst_RT(ir) >> 2];
1375 		if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
1376 			xcp->regs[MIPSInst_RD(ir)] =
1377 				xcp->regs[MIPSInst_RS(ir)];
1378 		break;
1379 	default:
1380 		return SIGILL;
1381 	}
1382 
1383 	/* we did it !! */
1384 	xcp->cp0_epc = contpc;
1385 	clear_delay_slot(xcp);
1386 
1387 	return 0;
1388 }
1389 
1390 /*
1391  * Conversion table from MIPS compare ops 48-63
1392  * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
1393  */
1394 static const unsigned char cmptab[8] = {
1395 	0,			/* cmp_0 (sig) cmp_sf */
1396 	IEEE754_CUN,		/* cmp_un (sig) cmp_ngle */
1397 	IEEE754_CEQ,		/* cmp_eq (sig) cmp_seq */
1398 	IEEE754_CEQ | IEEE754_CUN,	/* cmp_ueq (sig) cmp_ngl  */
1399 	IEEE754_CLT,		/* cmp_olt (sig) cmp_lt */
1400 	IEEE754_CLT | IEEE754_CUN,	/* cmp_ult (sig) cmp_nge */
1401 	IEEE754_CLT | IEEE754_CEQ,	/* cmp_ole (sig) cmp_le */
1402 	IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN,	/* cmp_ule (sig) cmp_ngt */
1403 };
1404 
1405 static const unsigned char negative_cmptab[8] = {
1406 	0, /* Reserved */
1407 	IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ,
1408 	IEEE754_CLT | IEEE754_CGT | IEEE754_CUN,
1409 	IEEE754_CLT | IEEE754_CGT,
1410 	/* Reserved */
1411 };
1412 
1413 
1414 /*
1415  * Additional MIPS4 instructions
1416  */
1417 
1418 #define DEF3OP(name, p, f1, f2, f3)					\
1419 static union ieee754##p fpemu_##p##_##name(union ieee754##p r,		\
1420 	union ieee754##p s, union ieee754##p t)				\
1421 {									\
1422 	struct _ieee754_csr ieee754_csr_save;				\
1423 	s = f1(s, t);							\
1424 	ieee754_csr_save = ieee754_csr;					\
1425 	s = f2(s, r);							\
1426 	ieee754_csr_save.cx |= ieee754_csr.cx;				\
1427 	ieee754_csr_save.sx |= ieee754_csr.sx;				\
1428 	s = f3(s);							\
1429 	ieee754_csr.cx |= ieee754_csr_save.cx;				\
1430 	ieee754_csr.sx |= ieee754_csr_save.sx;				\
1431 	return s;							\
1432 }
1433 
1434 static union ieee754dp fpemu_dp_recip(union ieee754dp d)
1435 {
1436 	return ieee754dp_div(ieee754dp_one(0), d);
1437 }
1438 
1439 static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
1440 {
1441 	return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
1442 }
1443 
1444 static union ieee754sp fpemu_sp_recip(union ieee754sp s)
1445 {
1446 	return ieee754sp_div(ieee754sp_one(0), s);
1447 }
1448 
1449 static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s)
1450 {
1451 	return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
1452 }
1453 
1454 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
1455 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
1456 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
1457 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
1458 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
1459 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
1460 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
1461 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
1462 
1463 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1464 	mips_instruction ir, void __user **fault_addr)
1465 {
1466 	unsigned int rcsr = 0;	/* resulting csr */
1467 
1468 	MIPS_FPU_EMU_INC_STATS(cp1xops);
1469 
1470 	switch (MIPSInst_FMA_FFMT(ir)) {
1471 	case s_fmt:{		/* 0 */
1472 
1473 		union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
1474 		union ieee754sp fd, fr, fs, ft;
1475 		u32 __user *va;
1476 		u32 val;
1477 
1478 		switch (MIPSInst_FUNC(ir)) {
1479 		case lwxc1_op:
1480 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1481 				xcp->regs[MIPSInst_FT(ir)]);
1482 
1483 			MIPS_FPU_EMU_INC_STATS(loads);
1484 			if (!access_ok(va, sizeof(u32))) {
1485 				MIPS_FPU_EMU_INC_STATS(errors);
1486 				*fault_addr = va;
1487 				return SIGBUS;
1488 			}
1489 			if (__get_user(val, va)) {
1490 				MIPS_FPU_EMU_INC_STATS(errors);
1491 				*fault_addr = va;
1492 				return SIGSEGV;
1493 			}
1494 			SITOREG(val, MIPSInst_FD(ir));
1495 			break;
1496 
1497 		case swxc1_op:
1498 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1499 				xcp->regs[MIPSInst_FT(ir)]);
1500 
1501 			MIPS_FPU_EMU_INC_STATS(stores);
1502 
1503 			SIFROMREG(val, MIPSInst_FS(ir));
1504 			if (!access_ok(va, sizeof(u32))) {
1505 				MIPS_FPU_EMU_INC_STATS(errors);
1506 				*fault_addr = va;
1507 				return SIGBUS;
1508 			}
1509 			if (put_user(val, va)) {
1510 				MIPS_FPU_EMU_INC_STATS(errors);
1511 				*fault_addr = va;
1512 				return SIGSEGV;
1513 			}
1514 			break;
1515 
1516 		case madd_s_op:
1517 			handler = fpemu_sp_madd;
1518 			goto scoptop;
1519 		case msub_s_op:
1520 			handler = fpemu_sp_msub;
1521 			goto scoptop;
1522 		case nmadd_s_op:
1523 			handler = fpemu_sp_nmadd;
1524 			goto scoptop;
1525 		case nmsub_s_op:
1526 			handler = fpemu_sp_nmsub;
1527 			goto scoptop;
1528 
1529 		      scoptop:
1530 			SPFROMREG(fr, MIPSInst_FR(ir));
1531 			SPFROMREG(fs, MIPSInst_FS(ir));
1532 			SPFROMREG(ft, MIPSInst_FT(ir));
1533 			fd = (*handler) (fr, fs, ft);
1534 			SPTOREG(fd, MIPSInst_FD(ir));
1535 
1536 		      copcsr:
1537 			if (ieee754_cxtest(IEEE754_INEXACT)) {
1538 				MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1539 				rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1540 			}
1541 			if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1542 				MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1543 				rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1544 			}
1545 			if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1546 				MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1547 				rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1548 			}
1549 			if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1550 				MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1551 				rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1552 			}
1553 
1554 			ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1555 			if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1556 				/*printk ("SIGFPE: FPU csr = %08x\n",
1557 				   ctx->fcr31); */
1558 				return SIGFPE;
1559 			}
1560 
1561 			break;
1562 
1563 		default:
1564 			return SIGILL;
1565 		}
1566 		break;
1567 	}
1568 
1569 	case d_fmt:{		/* 1 */
1570 		union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
1571 		union ieee754dp fd, fr, fs, ft;
1572 		u64 __user *va;
1573 		u64 val;
1574 
1575 		switch (MIPSInst_FUNC(ir)) {
1576 		case ldxc1_op:
1577 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1578 				xcp->regs[MIPSInst_FT(ir)]);
1579 
1580 			MIPS_FPU_EMU_INC_STATS(loads);
1581 			if (!access_ok(va, sizeof(u64))) {
1582 				MIPS_FPU_EMU_INC_STATS(errors);
1583 				*fault_addr = va;
1584 				return SIGBUS;
1585 			}
1586 			if (__get_user(val, va)) {
1587 				MIPS_FPU_EMU_INC_STATS(errors);
1588 				*fault_addr = va;
1589 				return SIGSEGV;
1590 			}
1591 			DITOREG(val, MIPSInst_FD(ir));
1592 			break;
1593 
1594 		case sdxc1_op:
1595 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1596 				xcp->regs[MIPSInst_FT(ir)]);
1597 
1598 			MIPS_FPU_EMU_INC_STATS(stores);
1599 			DIFROMREG(val, MIPSInst_FS(ir));
1600 			if (!access_ok(va, sizeof(u64))) {
1601 				MIPS_FPU_EMU_INC_STATS(errors);
1602 				*fault_addr = va;
1603 				return SIGBUS;
1604 			}
1605 			if (__put_user(val, va)) {
1606 				MIPS_FPU_EMU_INC_STATS(errors);
1607 				*fault_addr = va;
1608 				return SIGSEGV;
1609 			}
1610 			break;
1611 
1612 		case madd_d_op:
1613 			handler = fpemu_dp_madd;
1614 			goto dcoptop;
1615 		case msub_d_op:
1616 			handler = fpemu_dp_msub;
1617 			goto dcoptop;
1618 		case nmadd_d_op:
1619 			handler = fpemu_dp_nmadd;
1620 			goto dcoptop;
1621 		case nmsub_d_op:
1622 			handler = fpemu_dp_nmsub;
1623 			goto dcoptop;
1624 
1625 		      dcoptop:
1626 			DPFROMREG(fr, MIPSInst_FR(ir));
1627 			DPFROMREG(fs, MIPSInst_FS(ir));
1628 			DPFROMREG(ft, MIPSInst_FT(ir));
1629 			fd = (*handler) (fr, fs, ft);
1630 			DPTOREG(fd, MIPSInst_FD(ir));
1631 			goto copcsr;
1632 
1633 		default:
1634 			return SIGILL;
1635 		}
1636 		break;
1637 	}
1638 
1639 	case 0x3:
1640 		if (MIPSInst_FUNC(ir) != pfetch_op)
1641 			return SIGILL;
1642 
1643 		/* ignore prefx operation */
1644 		break;
1645 
1646 	default:
1647 		return SIGILL;
1648 	}
1649 
1650 	return 0;
1651 }
1652 
1653 
1654 
1655 /*
1656  * Emulate a single COP1 arithmetic instruction.
1657  */
1658 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1659 	mips_instruction ir)
1660 {
1661 	int rfmt;		/* resulting format */
1662 	unsigned int rcsr = 0;	/* resulting csr */
1663 	unsigned int oldrm;
1664 	unsigned int cbit;
1665 	unsigned int cond;
1666 	union {
1667 		union ieee754dp d;
1668 		union ieee754sp s;
1669 		int w;
1670 		s64 l;
1671 	} rv;			/* resulting value */
1672 	u64 bits;
1673 
1674 	MIPS_FPU_EMU_INC_STATS(cp1ops);
1675 	switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
1676 	case s_fmt: {		/* 0 */
1677 		union {
1678 			union ieee754sp(*b) (union ieee754sp, union ieee754sp);
1679 			union ieee754sp(*u) (union ieee754sp);
1680 		} handler;
1681 		union ieee754sp fd, fs, ft;
1682 
1683 		switch (MIPSInst_FUNC(ir)) {
1684 			/* binary ops */
1685 		case fadd_op:
1686 			MIPS_FPU_EMU_INC_STATS(add_s);
1687 			handler.b = ieee754sp_add;
1688 			goto scopbop;
1689 		case fsub_op:
1690 			MIPS_FPU_EMU_INC_STATS(sub_s);
1691 			handler.b = ieee754sp_sub;
1692 			goto scopbop;
1693 		case fmul_op:
1694 			MIPS_FPU_EMU_INC_STATS(mul_s);
1695 			handler.b = ieee754sp_mul;
1696 			goto scopbop;
1697 		case fdiv_op:
1698 			MIPS_FPU_EMU_INC_STATS(div_s);
1699 			handler.b = ieee754sp_div;
1700 			goto scopbop;
1701 
1702 			/* unary  ops */
1703 		case fsqrt_op:
1704 			if (!cpu_has_mips_2_3_4_5_r)
1705 				return SIGILL;
1706 
1707 			MIPS_FPU_EMU_INC_STATS(sqrt_s);
1708 			handler.u = ieee754sp_sqrt;
1709 			goto scopuop;
1710 
1711 		/*
1712 		 * Note that on some MIPS IV implementations such as the
1713 		 * R5000 and R8000 the FSQRT and FRECIP instructions do not
1714 		 * achieve full IEEE-754 accuracy - however this emulator does.
1715 		 */
1716 		case frsqrt_op:
1717 			if (!cpu_has_mips_4_5_64_r2_r6)
1718 				return SIGILL;
1719 
1720 			MIPS_FPU_EMU_INC_STATS(rsqrt_s);
1721 			handler.u = fpemu_sp_rsqrt;
1722 			goto scopuop;
1723 
1724 		case frecip_op:
1725 			if (!cpu_has_mips_4_5_64_r2_r6)
1726 				return SIGILL;
1727 
1728 			MIPS_FPU_EMU_INC_STATS(recip_s);
1729 			handler.u = fpemu_sp_recip;
1730 			goto scopuop;
1731 
1732 		case fmovc_op:
1733 			if (!cpu_has_mips_4_5_r)
1734 				return SIGILL;
1735 
1736 			cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1737 			if (((ctx->fcr31 & cond) != 0) !=
1738 				((MIPSInst_FT(ir) & 1) != 0))
1739 				return 0;
1740 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1741 			break;
1742 
1743 		case fmovz_op:
1744 			if (!cpu_has_mips_4_5_r)
1745 				return SIGILL;
1746 
1747 			if (xcp->regs[MIPSInst_FT(ir)] != 0)
1748 				return 0;
1749 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1750 			break;
1751 
1752 		case fmovn_op:
1753 			if (!cpu_has_mips_4_5_r)
1754 				return SIGILL;
1755 
1756 			if (xcp->regs[MIPSInst_FT(ir)] == 0)
1757 				return 0;
1758 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1759 			break;
1760 
1761 		case fseleqz_op:
1762 			if (!cpu_has_mips_r6)
1763 				return SIGILL;
1764 
1765 			MIPS_FPU_EMU_INC_STATS(seleqz_s);
1766 			SPFROMREG(rv.s, MIPSInst_FT(ir));
1767 			if (rv.w & 0x1)
1768 				rv.w = 0;
1769 			else
1770 				SPFROMREG(rv.s, MIPSInst_FS(ir));
1771 			break;
1772 
1773 		case fselnez_op:
1774 			if (!cpu_has_mips_r6)
1775 				return SIGILL;
1776 
1777 			MIPS_FPU_EMU_INC_STATS(selnez_s);
1778 			SPFROMREG(rv.s, MIPSInst_FT(ir));
1779 			if (rv.w & 0x1)
1780 				SPFROMREG(rv.s, MIPSInst_FS(ir));
1781 			else
1782 				rv.w = 0;
1783 			break;
1784 
1785 		case fmaddf_op: {
1786 			union ieee754sp ft, fs, fd;
1787 
1788 			if (!cpu_has_mips_r6)
1789 				return SIGILL;
1790 
1791 			MIPS_FPU_EMU_INC_STATS(maddf_s);
1792 			SPFROMREG(ft, MIPSInst_FT(ir));
1793 			SPFROMREG(fs, MIPSInst_FS(ir));
1794 			SPFROMREG(fd, MIPSInst_FD(ir));
1795 			rv.s = ieee754sp_maddf(fd, fs, ft);
1796 			goto copcsr;
1797 		}
1798 
1799 		case fmsubf_op: {
1800 			union ieee754sp ft, fs, fd;
1801 
1802 			if (!cpu_has_mips_r6)
1803 				return SIGILL;
1804 
1805 			MIPS_FPU_EMU_INC_STATS(msubf_s);
1806 			SPFROMREG(ft, MIPSInst_FT(ir));
1807 			SPFROMREG(fs, MIPSInst_FS(ir));
1808 			SPFROMREG(fd, MIPSInst_FD(ir));
1809 			rv.s = ieee754sp_msubf(fd, fs, ft);
1810 			goto copcsr;
1811 		}
1812 
1813 		case frint_op: {
1814 			union ieee754sp fs;
1815 
1816 			if (!cpu_has_mips_r6)
1817 				return SIGILL;
1818 
1819 			MIPS_FPU_EMU_INC_STATS(rint_s);
1820 			SPFROMREG(fs, MIPSInst_FS(ir));
1821 			rv.s = ieee754sp_rint(fs);
1822 			goto copcsr;
1823 		}
1824 
1825 		case fclass_op: {
1826 			union ieee754sp fs;
1827 
1828 			if (!cpu_has_mips_r6)
1829 				return SIGILL;
1830 
1831 			MIPS_FPU_EMU_INC_STATS(class_s);
1832 			SPFROMREG(fs, MIPSInst_FS(ir));
1833 			rv.w = ieee754sp_2008class(fs);
1834 			rfmt = w_fmt;
1835 			goto copcsr;
1836 		}
1837 
1838 		case fmin_op: {
1839 			union ieee754sp fs, ft;
1840 
1841 			if (!cpu_has_mips_r6)
1842 				return SIGILL;
1843 
1844 			MIPS_FPU_EMU_INC_STATS(min_s);
1845 			SPFROMREG(ft, MIPSInst_FT(ir));
1846 			SPFROMREG(fs, MIPSInst_FS(ir));
1847 			rv.s = ieee754sp_fmin(fs, ft);
1848 			goto copcsr;
1849 		}
1850 
1851 		case fmina_op: {
1852 			union ieee754sp fs, ft;
1853 
1854 			if (!cpu_has_mips_r6)
1855 				return SIGILL;
1856 
1857 			MIPS_FPU_EMU_INC_STATS(mina_s);
1858 			SPFROMREG(ft, MIPSInst_FT(ir));
1859 			SPFROMREG(fs, MIPSInst_FS(ir));
1860 			rv.s = ieee754sp_fmina(fs, ft);
1861 			goto copcsr;
1862 		}
1863 
1864 		case fmax_op: {
1865 			union ieee754sp fs, ft;
1866 
1867 			if (!cpu_has_mips_r6)
1868 				return SIGILL;
1869 
1870 			MIPS_FPU_EMU_INC_STATS(max_s);
1871 			SPFROMREG(ft, MIPSInst_FT(ir));
1872 			SPFROMREG(fs, MIPSInst_FS(ir));
1873 			rv.s = ieee754sp_fmax(fs, ft);
1874 			goto copcsr;
1875 		}
1876 
1877 		case fmaxa_op: {
1878 			union ieee754sp fs, ft;
1879 
1880 			if (!cpu_has_mips_r6)
1881 				return SIGILL;
1882 
1883 			MIPS_FPU_EMU_INC_STATS(maxa_s);
1884 			SPFROMREG(ft, MIPSInst_FT(ir));
1885 			SPFROMREG(fs, MIPSInst_FS(ir));
1886 			rv.s = ieee754sp_fmaxa(fs, ft);
1887 			goto copcsr;
1888 		}
1889 
1890 		case fabs_op:
1891 			MIPS_FPU_EMU_INC_STATS(abs_s);
1892 			handler.u = ieee754sp_abs;
1893 			goto scopuop;
1894 
1895 		case fneg_op:
1896 			MIPS_FPU_EMU_INC_STATS(neg_s);
1897 			handler.u = ieee754sp_neg;
1898 			goto scopuop;
1899 
1900 		case fmov_op:
1901 			/* an easy one */
1902 			MIPS_FPU_EMU_INC_STATS(mov_s);
1903 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1904 			goto copcsr;
1905 
1906 			/* binary op on handler */
1907 scopbop:
1908 			SPFROMREG(fs, MIPSInst_FS(ir));
1909 			SPFROMREG(ft, MIPSInst_FT(ir));
1910 
1911 			rv.s = (*handler.b) (fs, ft);
1912 			goto copcsr;
1913 scopuop:
1914 			SPFROMREG(fs, MIPSInst_FS(ir));
1915 			rv.s = (*handler.u) (fs);
1916 			goto copcsr;
1917 copcsr:
1918 			if (ieee754_cxtest(IEEE754_INEXACT)) {
1919 				MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1920 				rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1921 			}
1922 			if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1923 				MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1924 				rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1925 			}
1926 			if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1927 				MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1928 				rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1929 			}
1930 			if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) {
1931 				MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv);
1932 				rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
1933 			}
1934 			if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1935 				MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1936 				rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1937 			}
1938 			break;
1939 
1940 			/* unary conv ops */
1941 		case fcvts_op:
1942 			return SIGILL;	/* not defined */
1943 
1944 		case fcvtd_op:
1945 			MIPS_FPU_EMU_INC_STATS(cvt_d_s);
1946 			SPFROMREG(fs, MIPSInst_FS(ir));
1947 			rv.d = ieee754dp_fsp(fs);
1948 			rfmt = d_fmt;
1949 			goto copcsr;
1950 
1951 		case fcvtw_op:
1952 			MIPS_FPU_EMU_INC_STATS(cvt_w_s);
1953 			SPFROMREG(fs, MIPSInst_FS(ir));
1954 			rv.w = ieee754sp_tint(fs);
1955 			rfmt = w_fmt;
1956 			goto copcsr;
1957 
1958 		case fround_op:
1959 		case ftrunc_op:
1960 		case fceil_op:
1961 		case ffloor_op:
1962 			if (!cpu_has_mips_2_3_4_5_r)
1963 				return SIGILL;
1964 
1965 			if (MIPSInst_FUNC(ir) == fceil_op)
1966 				MIPS_FPU_EMU_INC_STATS(ceil_w_s);
1967 			if (MIPSInst_FUNC(ir) == ffloor_op)
1968 				MIPS_FPU_EMU_INC_STATS(floor_w_s);
1969 			if (MIPSInst_FUNC(ir) == fround_op)
1970 				MIPS_FPU_EMU_INC_STATS(round_w_s);
1971 			if (MIPSInst_FUNC(ir) == ftrunc_op)
1972 				MIPS_FPU_EMU_INC_STATS(trunc_w_s);
1973 
1974 			oldrm = ieee754_csr.rm;
1975 			SPFROMREG(fs, MIPSInst_FS(ir));
1976 			ieee754_csr.rm = MIPSInst_FUNC(ir);
1977 			rv.w = ieee754sp_tint(fs);
1978 			ieee754_csr.rm = oldrm;
1979 			rfmt = w_fmt;
1980 			goto copcsr;
1981 
1982 		case fsel_op:
1983 			if (!cpu_has_mips_r6)
1984 				return SIGILL;
1985 
1986 			MIPS_FPU_EMU_INC_STATS(sel_s);
1987 			SPFROMREG(fd, MIPSInst_FD(ir));
1988 			if (fd.bits & 0x1)
1989 				SPFROMREG(rv.s, MIPSInst_FT(ir));
1990 			else
1991 				SPFROMREG(rv.s, MIPSInst_FS(ir));
1992 			break;
1993 
1994 		case fcvtl_op:
1995 			if (!cpu_has_mips_3_4_5_64_r2_r6)
1996 				return SIGILL;
1997 
1998 			MIPS_FPU_EMU_INC_STATS(cvt_l_s);
1999 			SPFROMREG(fs, MIPSInst_FS(ir));
2000 			rv.l = ieee754sp_tlong(fs);
2001 			rfmt = l_fmt;
2002 			goto copcsr;
2003 
2004 		case froundl_op:
2005 		case ftruncl_op:
2006 		case fceill_op:
2007 		case ffloorl_op:
2008 			if (!cpu_has_mips_3_4_5_64_r2_r6)
2009 				return SIGILL;
2010 
2011 			if (MIPSInst_FUNC(ir) == fceill_op)
2012 				MIPS_FPU_EMU_INC_STATS(ceil_l_s);
2013 			if (MIPSInst_FUNC(ir) == ffloorl_op)
2014 				MIPS_FPU_EMU_INC_STATS(floor_l_s);
2015 			if (MIPSInst_FUNC(ir) == froundl_op)
2016 				MIPS_FPU_EMU_INC_STATS(round_l_s);
2017 			if (MIPSInst_FUNC(ir) == ftruncl_op)
2018 				MIPS_FPU_EMU_INC_STATS(trunc_l_s);
2019 
2020 			oldrm = ieee754_csr.rm;
2021 			SPFROMREG(fs, MIPSInst_FS(ir));
2022 			ieee754_csr.rm = MIPSInst_FUNC(ir);
2023 			rv.l = ieee754sp_tlong(fs);
2024 			ieee754_csr.rm = oldrm;
2025 			rfmt = l_fmt;
2026 			goto copcsr;
2027 
2028 		default:
2029 			if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2030 				unsigned int cmpop;
2031 				union ieee754sp fs, ft;
2032 
2033 				cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2034 				SPFROMREG(fs, MIPSInst_FS(ir));
2035 				SPFROMREG(ft, MIPSInst_FT(ir));
2036 				rv.w = ieee754sp_cmp(fs, ft,
2037 					cmptab[cmpop & 0x7], cmpop & 0x8);
2038 				rfmt = -1;
2039 				if ((cmpop & 0x8) && ieee754_cxtest
2040 					(IEEE754_INVALID_OPERATION))
2041 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2042 				else
2043 					goto copcsr;
2044 
2045 			} else
2046 				return SIGILL;
2047 			break;
2048 		}
2049 		break;
2050 	}
2051 
2052 	case d_fmt: {
2053 		union ieee754dp fd, fs, ft;
2054 		union {
2055 			union ieee754dp(*b) (union ieee754dp, union ieee754dp);
2056 			union ieee754dp(*u) (union ieee754dp);
2057 		} handler;
2058 
2059 		switch (MIPSInst_FUNC(ir)) {
2060 			/* binary ops */
2061 		case fadd_op:
2062 			MIPS_FPU_EMU_INC_STATS(add_d);
2063 			handler.b = ieee754dp_add;
2064 			goto dcopbop;
2065 		case fsub_op:
2066 			MIPS_FPU_EMU_INC_STATS(sub_d);
2067 			handler.b = ieee754dp_sub;
2068 			goto dcopbop;
2069 		case fmul_op:
2070 			MIPS_FPU_EMU_INC_STATS(mul_d);
2071 			handler.b = ieee754dp_mul;
2072 			goto dcopbop;
2073 		case fdiv_op:
2074 			MIPS_FPU_EMU_INC_STATS(div_d);
2075 			handler.b = ieee754dp_div;
2076 			goto dcopbop;
2077 
2078 			/* unary  ops */
2079 		case fsqrt_op:
2080 			if (!cpu_has_mips_2_3_4_5_r)
2081 				return SIGILL;
2082 
2083 			MIPS_FPU_EMU_INC_STATS(sqrt_d);
2084 			handler.u = ieee754dp_sqrt;
2085 			goto dcopuop;
2086 		/*
2087 		 * Note that on some MIPS IV implementations such as the
2088 		 * R5000 and R8000 the FSQRT and FRECIP instructions do not
2089 		 * achieve full IEEE-754 accuracy - however this emulator does.
2090 		 */
2091 		case frsqrt_op:
2092 			if (!cpu_has_mips_4_5_64_r2_r6)
2093 				return SIGILL;
2094 
2095 			MIPS_FPU_EMU_INC_STATS(rsqrt_d);
2096 			handler.u = fpemu_dp_rsqrt;
2097 			goto dcopuop;
2098 		case frecip_op:
2099 			if (!cpu_has_mips_4_5_64_r2_r6)
2100 				return SIGILL;
2101 
2102 			MIPS_FPU_EMU_INC_STATS(recip_d);
2103 			handler.u = fpemu_dp_recip;
2104 			goto dcopuop;
2105 		case fmovc_op:
2106 			if (!cpu_has_mips_4_5_r)
2107 				return SIGILL;
2108 
2109 			cond = fpucondbit[MIPSInst_FT(ir) >> 2];
2110 			if (((ctx->fcr31 & cond) != 0) !=
2111 				((MIPSInst_FT(ir) & 1) != 0))
2112 				return 0;
2113 			DPFROMREG(rv.d, MIPSInst_FS(ir));
2114 			break;
2115 		case fmovz_op:
2116 			if (!cpu_has_mips_4_5_r)
2117 				return SIGILL;
2118 
2119 			if (xcp->regs[MIPSInst_FT(ir)] != 0)
2120 				return 0;
2121 			DPFROMREG(rv.d, MIPSInst_FS(ir));
2122 			break;
2123 		case fmovn_op:
2124 			if (!cpu_has_mips_4_5_r)
2125 				return SIGILL;
2126 
2127 			if (xcp->regs[MIPSInst_FT(ir)] == 0)
2128 				return 0;
2129 			DPFROMREG(rv.d, MIPSInst_FS(ir));
2130 			break;
2131 
2132 		case fseleqz_op:
2133 			if (!cpu_has_mips_r6)
2134 				return SIGILL;
2135 
2136 			MIPS_FPU_EMU_INC_STATS(seleqz_d);
2137 			DPFROMREG(rv.d, MIPSInst_FT(ir));
2138 			if (rv.l & 0x1)
2139 				rv.l = 0;
2140 			else
2141 				DPFROMREG(rv.d, MIPSInst_FS(ir));
2142 			break;
2143 
2144 		case fselnez_op:
2145 			if (!cpu_has_mips_r6)
2146 				return SIGILL;
2147 
2148 			MIPS_FPU_EMU_INC_STATS(selnez_d);
2149 			DPFROMREG(rv.d, MIPSInst_FT(ir));
2150 			if (rv.l & 0x1)
2151 				DPFROMREG(rv.d, MIPSInst_FS(ir));
2152 			else
2153 				rv.l = 0;
2154 			break;
2155 
2156 		case fmaddf_op: {
2157 			union ieee754dp ft, fs, fd;
2158 
2159 			if (!cpu_has_mips_r6)
2160 				return SIGILL;
2161 
2162 			MIPS_FPU_EMU_INC_STATS(maddf_d);
2163 			DPFROMREG(ft, MIPSInst_FT(ir));
2164 			DPFROMREG(fs, MIPSInst_FS(ir));
2165 			DPFROMREG(fd, MIPSInst_FD(ir));
2166 			rv.d = ieee754dp_maddf(fd, fs, ft);
2167 			goto copcsr;
2168 		}
2169 
2170 		case fmsubf_op: {
2171 			union ieee754dp ft, fs, fd;
2172 
2173 			if (!cpu_has_mips_r6)
2174 				return SIGILL;
2175 
2176 			MIPS_FPU_EMU_INC_STATS(msubf_d);
2177 			DPFROMREG(ft, MIPSInst_FT(ir));
2178 			DPFROMREG(fs, MIPSInst_FS(ir));
2179 			DPFROMREG(fd, MIPSInst_FD(ir));
2180 			rv.d = ieee754dp_msubf(fd, fs, ft);
2181 			goto copcsr;
2182 		}
2183 
2184 		case frint_op: {
2185 			union ieee754dp fs;
2186 
2187 			if (!cpu_has_mips_r6)
2188 				return SIGILL;
2189 
2190 			MIPS_FPU_EMU_INC_STATS(rint_d);
2191 			DPFROMREG(fs, MIPSInst_FS(ir));
2192 			rv.d = ieee754dp_rint(fs);
2193 			goto copcsr;
2194 		}
2195 
2196 		case fclass_op: {
2197 			union ieee754dp fs;
2198 
2199 			if (!cpu_has_mips_r6)
2200 				return SIGILL;
2201 
2202 			MIPS_FPU_EMU_INC_STATS(class_d);
2203 			DPFROMREG(fs, MIPSInst_FS(ir));
2204 			rv.l = ieee754dp_2008class(fs);
2205 			rfmt = l_fmt;
2206 			goto copcsr;
2207 		}
2208 
2209 		case fmin_op: {
2210 			union ieee754dp fs, ft;
2211 
2212 			if (!cpu_has_mips_r6)
2213 				return SIGILL;
2214 
2215 			MIPS_FPU_EMU_INC_STATS(min_d);
2216 			DPFROMREG(ft, MIPSInst_FT(ir));
2217 			DPFROMREG(fs, MIPSInst_FS(ir));
2218 			rv.d = ieee754dp_fmin(fs, ft);
2219 			goto copcsr;
2220 		}
2221 
2222 		case fmina_op: {
2223 			union ieee754dp fs, ft;
2224 
2225 			if (!cpu_has_mips_r6)
2226 				return SIGILL;
2227 
2228 			MIPS_FPU_EMU_INC_STATS(mina_d);
2229 			DPFROMREG(ft, MIPSInst_FT(ir));
2230 			DPFROMREG(fs, MIPSInst_FS(ir));
2231 			rv.d = ieee754dp_fmina(fs, ft);
2232 			goto copcsr;
2233 		}
2234 
2235 		case fmax_op: {
2236 			union ieee754dp fs, ft;
2237 
2238 			if (!cpu_has_mips_r6)
2239 				return SIGILL;
2240 
2241 			MIPS_FPU_EMU_INC_STATS(max_d);
2242 			DPFROMREG(ft, MIPSInst_FT(ir));
2243 			DPFROMREG(fs, MIPSInst_FS(ir));
2244 			rv.d = ieee754dp_fmax(fs, ft);
2245 			goto copcsr;
2246 		}
2247 
2248 		case fmaxa_op: {
2249 			union ieee754dp fs, ft;
2250 
2251 			if (!cpu_has_mips_r6)
2252 				return SIGILL;
2253 
2254 			MIPS_FPU_EMU_INC_STATS(maxa_d);
2255 			DPFROMREG(ft, MIPSInst_FT(ir));
2256 			DPFROMREG(fs, MIPSInst_FS(ir));
2257 			rv.d = ieee754dp_fmaxa(fs, ft);
2258 			goto copcsr;
2259 		}
2260 
2261 		case fabs_op:
2262 			MIPS_FPU_EMU_INC_STATS(abs_d);
2263 			handler.u = ieee754dp_abs;
2264 			goto dcopuop;
2265 
2266 		case fneg_op:
2267 			MIPS_FPU_EMU_INC_STATS(neg_d);
2268 			handler.u = ieee754dp_neg;
2269 			goto dcopuop;
2270 
2271 		case fmov_op:
2272 			/* an easy one */
2273 			MIPS_FPU_EMU_INC_STATS(mov_d);
2274 			DPFROMREG(rv.d, MIPSInst_FS(ir));
2275 			goto copcsr;
2276 
2277 			/* binary op on handler */
2278 dcopbop:
2279 			DPFROMREG(fs, MIPSInst_FS(ir));
2280 			DPFROMREG(ft, MIPSInst_FT(ir));
2281 
2282 			rv.d = (*handler.b) (fs, ft);
2283 			goto copcsr;
2284 dcopuop:
2285 			DPFROMREG(fs, MIPSInst_FS(ir));
2286 			rv.d = (*handler.u) (fs);
2287 			goto copcsr;
2288 
2289 		/*
2290 		 * unary conv ops
2291 		 */
2292 		case fcvts_op:
2293 			MIPS_FPU_EMU_INC_STATS(cvt_s_d);
2294 			DPFROMREG(fs, MIPSInst_FS(ir));
2295 			rv.s = ieee754sp_fdp(fs);
2296 			rfmt = s_fmt;
2297 			goto copcsr;
2298 
2299 		case fcvtd_op:
2300 			return SIGILL;	/* not defined */
2301 
2302 		case fcvtw_op:
2303 			MIPS_FPU_EMU_INC_STATS(cvt_w_d);
2304 			DPFROMREG(fs, MIPSInst_FS(ir));
2305 			rv.w = ieee754dp_tint(fs);	/* wrong */
2306 			rfmt = w_fmt;
2307 			goto copcsr;
2308 
2309 		case fround_op:
2310 		case ftrunc_op:
2311 		case fceil_op:
2312 		case ffloor_op:
2313 			if (!cpu_has_mips_2_3_4_5_r)
2314 				return SIGILL;
2315 
2316 			if (MIPSInst_FUNC(ir) == fceil_op)
2317 				MIPS_FPU_EMU_INC_STATS(ceil_w_d);
2318 			if (MIPSInst_FUNC(ir) == ffloor_op)
2319 				MIPS_FPU_EMU_INC_STATS(floor_w_d);
2320 			if (MIPSInst_FUNC(ir) == fround_op)
2321 				MIPS_FPU_EMU_INC_STATS(round_w_d);
2322 			if (MIPSInst_FUNC(ir) == ftrunc_op)
2323 				MIPS_FPU_EMU_INC_STATS(trunc_w_d);
2324 
2325 			oldrm = ieee754_csr.rm;
2326 			DPFROMREG(fs, MIPSInst_FS(ir));
2327 			ieee754_csr.rm = MIPSInst_FUNC(ir);
2328 			rv.w = ieee754dp_tint(fs);
2329 			ieee754_csr.rm = oldrm;
2330 			rfmt = w_fmt;
2331 			goto copcsr;
2332 
2333 		case fsel_op:
2334 			if (!cpu_has_mips_r6)
2335 				return SIGILL;
2336 
2337 			MIPS_FPU_EMU_INC_STATS(sel_d);
2338 			DPFROMREG(fd, MIPSInst_FD(ir));
2339 			if (fd.bits & 0x1)
2340 				DPFROMREG(rv.d, MIPSInst_FT(ir));
2341 			else
2342 				DPFROMREG(rv.d, MIPSInst_FS(ir));
2343 			break;
2344 
2345 		case fcvtl_op:
2346 			if (!cpu_has_mips_3_4_5_64_r2_r6)
2347 				return SIGILL;
2348 
2349 			MIPS_FPU_EMU_INC_STATS(cvt_l_d);
2350 			DPFROMREG(fs, MIPSInst_FS(ir));
2351 			rv.l = ieee754dp_tlong(fs);
2352 			rfmt = l_fmt;
2353 			goto copcsr;
2354 
2355 		case froundl_op:
2356 		case ftruncl_op:
2357 		case fceill_op:
2358 		case ffloorl_op:
2359 			if (!cpu_has_mips_3_4_5_64_r2_r6)
2360 				return SIGILL;
2361 
2362 			if (MIPSInst_FUNC(ir) == fceill_op)
2363 				MIPS_FPU_EMU_INC_STATS(ceil_l_d);
2364 			if (MIPSInst_FUNC(ir) == ffloorl_op)
2365 				MIPS_FPU_EMU_INC_STATS(floor_l_d);
2366 			if (MIPSInst_FUNC(ir) == froundl_op)
2367 				MIPS_FPU_EMU_INC_STATS(round_l_d);
2368 			if (MIPSInst_FUNC(ir) == ftruncl_op)
2369 				MIPS_FPU_EMU_INC_STATS(trunc_l_d);
2370 
2371 			oldrm = ieee754_csr.rm;
2372 			DPFROMREG(fs, MIPSInst_FS(ir));
2373 			ieee754_csr.rm = MIPSInst_FUNC(ir);
2374 			rv.l = ieee754dp_tlong(fs);
2375 			ieee754_csr.rm = oldrm;
2376 			rfmt = l_fmt;
2377 			goto copcsr;
2378 
2379 		default:
2380 			if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2381 				unsigned int cmpop;
2382 				union ieee754dp fs, ft;
2383 
2384 				cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2385 				DPFROMREG(fs, MIPSInst_FS(ir));
2386 				DPFROMREG(ft, MIPSInst_FT(ir));
2387 				rv.w = ieee754dp_cmp(fs, ft,
2388 					cmptab[cmpop & 0x7], cmpop & 0x8);
2389 				rfmt = -1;
2390 				if ((cmpop & 0x8)
2391 					&&
2392 					ieee754_cxtest
2393 					(IEEE754_INVALID_OPERATION))
2394 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2395 				else
2396 					goto copcsr;
2397 
2398 			}
2399 			else {
2400 				return SIGILL;
2401 			}
2402 			break;
2403 		}
2404 		break;
2405 	}
2406 
2407 	case w_fmt: {
2408 		union ieee754dp fs;
2409 
2410 		switch (MIPSInst_FUNC(ir)) {
2411 		case fcvts_op:
2412 			/* convert word to single precision real */
2413 			MIPS_FPU_EMU_INC_STATS(cvt_s_w);
2414 			SPFROMREG(fs, MIPSInst_FS(ir));
2415 			rv.s = ieee754sp_fint(fs.bits);
2416 			rfmt = s_fmt;
2417 			goto copcsr;
2418 		case fcvtd_op:
2419 			/* convert word to double precision real */
2420 			MIPS_FPU_EMU_INC_STATS(cvt_d_w);
2421 			SPFROMREG(fs, MIPSInst_FS(ir));
2422 			rv.d = ieee754dp_fint(fs.bits);
2423 			rfmt = d_fmt;
2424 			goto copcsr;
2425 		default: {
2426 			/* Emulating the new CMP.condn.fmt R6 instruction */
2427 #define CMPOP_MASK	0x7
2428 #define SIGN_BIT	(0x1 << 3)
2429 #define PREDICATE_BIT	(0x1 << 4)
2430 
2431 			int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2432 			int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2433 			union ieee754sp fs, ft;
2434 
2435 			/* This is an R6 only instruction */
2436 			if (!cpu_has_mips_r6 ||
2437 			    (MIPSInst_FUNC(ir) & 0x20))
2438 				return SIGILL;
2439 
2440 			if (!sig) {
2441 				if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2442 					switch (cmpop) {
2443 					case 0:
2444 					MIPS_FPU_EMU_INC_STATS(cmp_af_s);
2445 					break;
2446 					case 1:
2447 					MIPS_FPU_EMU_INC_STATS(cmp_un_s);
2448 					break;
2449 					case 2:
2450 					MIPS_FPU_EMU_INC_STATS(cmp_eq_s);
2451 					break;
2452 					case 3:
2453 					MIPS_FPU_EMU_INC_STATS(cmp_ueq_s);
2454 					break;
2455 					case 4:
2456 					MIPS_FPU_EMU_INC_STATS(cmp_lt_s);
2457 					break;
2458 					case 5:
2459 					MIPS_FPU_EMU_INC_STATS(cmp_ult_s);
2460 					break;
2461 					case 6:
2462 					MIPS_FPU_EMU_INC_STATS(cmp_le_s);
2463 					break;
2464 					case 7:
2465 					MIPS_FPU_EMU_INC_STATS(cmp_ule_s);
2466 					break;
2467 					}
2468 				} else {
2469 					switch (cmpop) {
2470 					case 1:
2471 					MIPS_FPU_EMU_INC_STATS(cmp_or_s);
2472 					break;
2473 					case 2:
2474 					MIPS_FPU_EMU_INC_STATS(cmp_une_s);
2475 					break;
2476 					case 3:
2477 					MIPS_FPU_EMU_INC_STATS(cmp_ne_s);
2478 					break;
2479 					}
2480 				}
2481 			} else {
2482 				if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2483 					switch (cmpop) {
2484 					case 0:
2485 					MIPS_FPU_EMU_INC_STATS(cmp_saf_s);
2486 					break;
2487 					case 1:
2488 					MIPS_FPU_EMU_INC_STATS(cmp_sun_s);
2489 					break;
2490 					case 2:
2491 					MIPS_FPU_EMU_INC_STATS(cmp_seq_s);
2492 					break;
2493 					case 3:
2494 					MIPS_FPU_EMU_INC_STATS(cmp_sueq_s);
2495 					break;
2496 					case 4:
2497 					MIPS_FPU_EMU_INC_STATS(cmp_slt_s);
2498 					break;
2499 					case 5:
2500 					MIPS_FPU_EMU_INC_STATS(cmp_sult_s);
2501 					break;
2502 					case 6:
2503 					MIPS_FPU_EMU_INC_STATS(cmp_sle_s);
2504 					break;
2505 					case 7:
2506 					MIPS_FPU_EMU_INC_STATS(cmp_sule_s);
2507 					break;
2508 					}
2509 				} else {
2510 					switch (cmpop) {
2511 					case 1:
2512 					MIPS_FPU_EMU_INC_STATS(cmp_sor_s);
2513 					break;
2514 					case 2:
2515 					MIPS_FPU_EMU_INC_STATS(cmp_sune_s);
2516 					break;
2517 					case 3:
2518 					MIPS_FPU_EMU_INC_STATS(cmp_sne_s);
2519 					break;
2520 					}
2521 				}
2522 			}
2523 
2524 			/* fmt is w_fmt for single precision so fix it */
2525 			rfmt = s_fmt;
2526 			/* default to false */
2527 			rv.w = 0;
2528 
2529 			/* CMP.condn.S */
2530 			SPFROMREG(fs, MIPSInst_FS(ir));
2531 			SPFROMREG(ft, MIPSInst_FT(ir));
2532 
2533 			/* positive predicates */
2534 			if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2535 				if (ieee754sp_cmp(fs, ft, cmptab[cmpop],
2536 						  sig))
2537 				    rv.w = -1; /* true, all 1s */
2538 				if ((sig) &&
2539 				    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2540 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2541 				else
2542 					goto copcsr;
2543 			} else {
2544 				/* negative predicates */
2545 				switch (cmpop) {
2546 				case 1:
2547 				case 2:
2548 				case 3:
2549 					if (ieee754sp_cmp(fs, ft,
2550 							  negative_cmptab[cmpop],
2551 							  sig))
2552 						rv.w = -1; /* true, all 1s */
2553 					if (sig &&
2554 					    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2555 						rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2556 					else
2557 						goto copcsr;
2558 					break;
2559 				default:
2560 					/* Reserved R6 ops */
2561 					return SIGILL;
2562 				}
2563 			}
2564 			break;
2565 			}
2566 		}
2567 		break;
2568 	}
2569 
2570 	case l_fmt:
2571 
2572 		if (!cpu_has_mips_3_4_5_64_r2_r6)
2573 			return SIGILL;
2574 
2575 		DIFROMREG(bits, MIPSInst_FS(ir));
2576 
2577 		switch (MIPSInst_FUNC(ir)) {
2578 		case fcvts_op:
2579 			/* convert long to single precision real */
2580 			MIPS_FPU_EMU_INC_STATS(cvt_s_l);
2581 			rv.s = ieee754sp_flong(bits);
2582 			rfmt = s_fmt;
2583 			goto copcsr;
2584 		case fcvtd_op:
2585 			/* convert long to double precision real */
2586 			MIPS_FPU_EMU_INC_STATS(cvt_d_l);
2587 			rv.d = ieee754dp_flong(bits);
2588 			rfmt = d_fmt;
2589 			goto copcsr;
2590 		default: {
2591 			/* Emulating the new CMP.condn.fmt R6 instruction */
2592 			int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2593 			int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2594 			union ieee754dp fs, ft;
2595 
2596 			if (!cpu_has_mips_r6 ||
2597 			    (MIPSInst_FUNC(ir) & 0x20))
2598 				return SIGILL;
2599 
2600 			if (!sig) {
2601 				if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2602 					switch (cmpop) {
2603 					case 0:
2604 					MIPS_FPU_EMU_INC_STATS(cmp_af_d);
2605 					break;
2606 					case 1:
2607 					MIPS_FPU_EMU_INC_STATS(cmp_un_d);
2608 					break;
2609 					case 2:
2610 					MIPS_FPU_EMU_INC_STATS(cmp_eq_d);
2611 					break;
2612 					case 3:
2613 					MIPS_FPU_EMU_INC_STATS(cmp_ueq_d);
2614 					break;
2615 					case 4:
2616 					MIPS_FPU_EMU_INC_STATS(cmp_lt_d);
2617 					break;
2618 					case 5:
2619 					MIPS_FPU_EMU_INC_STATS(cmp_ult_d);
2620 					break;
2621 					case 6:
2622 					MIPS_FPU_EMU_INC_STATS(cmp_le_d);
2623 					break;
2624 					case 7:
2625 					MIPS_FPU_EMU_INC_STATS(cmp_ule_d);
2626 					break;
2627 					}
2628 				} else {
2629 					switch (cmpop) {
2630 					case 1:
2631 					MIPS_FPU_EMU_INC_STATS(cmp_or_d);
2632 					break;
2633 					case 2:
2634 					MIPS_FPU_EMU_INC_STATS(cmp_une_d);
2635 					break;
2636 					case 3:
2637 					MIPS_FPU_EMU_INC_STATS(cmp_ne_d);
2638 					break;
2639 					}
2640 				}
2641 			} else {
2642 				if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2643 					switch (cmpop) {
2644 					case 0:
2645 					MIPS_FPU_EMU_INC_STATS(cmp_saf_d);
2646 					break;
2647 					case 1:
2648 					MIPS_FPU_EMU_INC_STATS(cmp_sun_d);
2649 					break;
2650 					case 2:
2651 					MIPS_FPU_EMU_INC_STATS(cmp_seq_d);
2652 					break;
2653 					case 3:
2654 					MIPS_FPU_EMU_INC_STATS(cmp_sueq_d);
2655 					break;
2656 					case 4:
2657 					MIPS_FPU_EMU_INC_STATS(cmp_slt_d);
2658 					break;
2659 					case 5:
2660 					MIPS_FPU_EMU_INC_STATS(cmp_sult_d);
2661 					break;
2662 					case 6:
2663 					MIPS_FPU_EMU_INC_STATS(cmp_sle_d);
2664 					break;
2665 					case 7:
2666 					MIPS_FPU_EMU_INC_STATS(cmp_sule_d);
2667 					break;
2668 					}
2669 				} else {
2670 					switch (cmpop) {
2671 					case 1:
2672 					MIPS_FPU_EMU_INC_STATS(cmp_sor_d);
2673 					break;
2674 					case 2:
2675 					MIPS_FPU_EMU_INC_STATS(cmp_sune_d);
2676 					break;
2677 					case 3:
2678 					MIPS_FPU_EMU_INC_STATS(cmp_sne_d);
2679 					break;
2680 					}
2681 				}
2682 			}
2683 
2684 			/* fmt is l_fmt for double precision so fix it */
2685 			rfmt = d_fmt;
2686 			/* default to false */
2687 			rv.l = 0;
2688 
2689 			/* CMP.condn.D */
2690 			DPFROMREG(fs, MIPSInst_FS(ir));
2691 			DPFROMREG(ft, MIPSInst_FT(ir));
2692 
2693 			/* positive predicates */
2694 			if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2695 				if (ieee754dp_cmp(fs, ft,
2696 						  cmptab[cmpop], sig))
2697 				    rv.l = -1LL; /* true, all 1s */
2698 				if (sig &&
2699 				    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2700 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2701 				else
2702 					goto copcsr;
2703 			} else {
2704 				/* negative predicates */
2705 				switch (cmpop) {
2706 				case 1:
2707 				case 2:
2708 				case 3:
2709 					if (ieee754dp_cmp(fs, ft,
2710 							  negative_cmptab[cmpop],
2711 							  sig))
2712 						rv.l = -1LL; /* true, all 1s */
2713 					if (sig &&
2714 					    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2715 						rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2716 					else
2717 						goto copcsr;
2718 					break;
2719 				default:
2720 					/* Reserved R6 ops */
2721 					return SIGILL;
2722 				}
2723 			}
2724 			break;
2725 			}
2726 		}
2727 		break;
2728 
2729 	default:
2730 		return SIGILL;
2731 	}
2732 
2733 	/*
2734 	 * Update the fpu CSR register for this operation.
2735 	 * If an exception is required, generate a tidy SIGFPE exception,
2736 	 * without updating the result register.
2737 	 * Note: cause exception bits do not accumulate, they are rewritten
2738 	 * for each op; only the flag/sticky bits accumulate.
2739 	 */
2740 	ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
2741 	if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
2742 		/*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */
2743 		return SIGFPE;
2744 	}
2745 
2746 	/*
2747 	 * Now we can safely write the result back to the register file.
2748 	 */
2749 	switch (rfmt) {
2750 	case -1:
2751 
2752 		if (cpu_has_mips_4_5_r)
2753 			cbit = fpucondbit[MIPSInst_FD(ir) >> 2];
2754 		else
2755 			cbit = FPU_CSR_COND;
2756 		if (rv.w)
2757 			ctx->fcr31 |= cbit;
2758 		else
2759 			ctx->fcr31 &= ~cbit;
2760 		break;
2761 
2762 	case d_fmt:
2763 		DPTOREG(rv.d, MIPSInst_FD(ir));
2764 		break;
2765 	case s_fmt:
2766 		SPTOREG(rv.s, MIPSInst_FD(ir));
2767 		break;
2768 	case w_fmt:
2769 		SITOREG(rv.w, MIPSInst_FD(ir));
2770 		break;
2771 	case l_fmt:
2772 		if (!cpu_has_mips_3_4_5_64_r2_r6)
2773 			return SIGILL;
2774 
2775 		DITOREG(rv.l, MIPSInst_FD(ir));
2776 		break;
2777 	default:
2778 		return SIGILL;
2779 	}
2780 
2781 	return 0;
2782 }
2783 
2784 /*
2785  * Emulate FPU instructions.
2786  *
2787  * If we use FPU hardware, then we have been typically called to handle
2788  * an unimplemented operation, such as where an operand is a NaN or
2789  * denormalized.  In that case exit the emulation loop after a single
2790  * iteration so as to let hardware execute any subsequent instructions.
2791  *
2792  * If we have no FPU hardware or it has been disabled, then continue
2793  * emulating floating-point instructions until one of these conditions
2794  * has occurred:
2795  *
2796  * - a non-FPU instruction has been encountered,
2797  *
2798  * - an attempt to emulate has ended with a signal,
2799  *
2800  * - the ISA mode has been switched.
2801  *
2802  * We need to terminate the emulation loop if we got switched to the
2803  * MIPS16 mode, whether supported or not, so that we do not attempt
2804  * to emulate a MIPS16 instruction as a regular MIPS FPU instruction.
2805  * Similarly if we got switched to the microMIPS mode and only the
2806  * regular MIPS mode is supported, so that we do not attempt to emulate
2807  * a microMIPS instruction as a regular MIPS FPU instruction.  Or if
2808  * we got switched to the regular MIPS mode and only the microMIPS mode
2809  * is supported, so that we do not attempt to emulate a regular MIPS
2810  * instruction that should cause an Address Error exception instead.
2811  * For simplicity we always terminate upon an ISA mode switch.
2812  */
2813 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
2814 	int has_fpu, void __user **fault_addr)
2815 {
2816 	unsigned long oldepc, prevepc;
2817 	struct mm_decoded_insn dec_insn;
2818 	u16 instr[4];
2819 	u16 *instr_ptr;
2820 	int sig = 0;
2821 
2822 	/*
2823 	 * Initialize context if it hasn't been used already, otherwise ensure
2824 	 * it has been saved to struct thread_struct.
2825 	 */
2826 	if (!init_fp_ctx(current))
2827 		lose_fpu(1);
2828 
2829 	oldepc = xcp->cp0_epc;
2830 	do {
2831 		prevepc = xcp->cp0_epc;
2832 
2833 		if (get_isa16_mode(prevepc) && cpu_has_mmips) {
2834 			/*
2835 			 * Get next 2 microMIPS instructions and convert them
2836 			 * into 32-bit instructions.
2837 			 */
2838 			if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
2839 			    (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
2840 			    (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
2841 			    (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
2842 				MIPS_FPU_EMU_INC_STATS(errors);
2843 				return SIGBUS;
2844 			}
2845 			instr_ptr = instr;
2846 
2847 			/* Get first instruction. */
2848 			if (mm_insn_16bit(*instr_ptr)) {
2849 				/* Duplicate the half-word. */
2850 				dec_insn.insn = (*instr_ptr << 16) |
2851 					(*instr_ptr);
2852 				/* 16-bit instruction. */
2853 				dec_insn.pc_inc = 2;
2854 				instr_ptr += 1;
2855 			} else {
2856 				dec_insn.insn = (*instr_ptr << 16) |
2857 					*(instr_ptr+1);
2858 				/* 32-bit instruction. */
2859 				dec_insn.pc_inc = 4;
2860 				instr_ptr += 2;
2861 			}
2862 			/* Get second instruction. */
2863 			if (mm_insn_16bit(*instr_ptr)) {
2864 				/* Duplicate the half-word. */
2865 				dec_insn.next_insn = (*instr_ptr << 16) |
2866 					(*instr_ptr);
2867 				/* 16-bit instruction. */
2868 				dec_insn.next_pc_inc = 2;
2869 			} else {
2870 				dec_insn.next_insn = (*instr_ptr << 16) |
2871 					*(instr_ptr+1);
2872 				/* 32-bit instruction. */
2873 				dec_insn.next_pc_inc = 4;
2874 			}
2875 			dec_insn.micro_mips_mode = 1;
2876 		} else {
2877 			if ((get_user(dec_insn.insn,
2878 			    (mips_instruction __user *) xcp->cp0_epc)) ||
2879 			    (get_user(dec_insn.next_insn,
2880 			    (mips_instruction __user *)(xcp->cp0_epc+4)))) {
2881 				MIPS_FPU_EMU_INC_STATS(errors);
2882 				return SIGBUS;
2883 			}
2884 			dec_insn.pc_inc = 4;
2885 			dec_insn.next_pc_inc = 4;
2886 			dec_insn.micro_mips_mode = 0;
2887 		}
2888 
2889 		if ((dec_insn.insn == 0) ||
2890 		   ((dec_insn.pc_inc == 2) &&
2891 		   ((dec_insn.insn & 0xffff) == MM_NOP16)))
2892 			xcp->cp0_epc += dec_insn.pc_inc;	/* Skip NOPs */
2893 		else {
2894 			/*
2895 			 * The 'ieee754_csr' is an alias of ctx->fcr31.
2896 			 * No need to copy ctx->fcr31 to ieee754_csr.
2897 			 */
2898 			sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
2899 		}
2900 
2901 		if (has_fpu)
2902 			break;
2903 		if (sig)
2904 			break;
2905 		/*
2906 		 * We have to check for the ISA bit explicitly here,
2907 		 * because `get_isa16_mode' may return 0 if support
2908 		 * for code compression has been globally disabled,
2909 		 * or otherwise we may produce the wrong signal or
2910 		 * even proceed successfully where we must not.
2911 		 */
2912 		if ((xcp->cp0_epc ^ prevepc) & 0x1)
2913 			break;
2914 
2915 		cond_resched();
2916 	} while (xcp->cp0_epc > prevepc);
2917 
2918 	/* SIGILL indicates a non-fpu instruction */
2919 	if (sig == SIGILL && xcp->cp0_epc != oldepc)
2920 		/* but if EPC has advanced, then ignore it */
2921 		sig = 0;
2922 
2923 	return sig;
2924 }
2925