xref: /openbmc/linux/arch/mips/math-emu/cp1emu.c (revision be709d48)
1 /*
2  * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator
3  *
4  * MIPS floating point support
5  * Copyright (C) 1994-2000 Algorithmics Ltd.
6  *
7  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
8  * Copyright (C) 2000  MIPS Technologies, Inc.
9  *
10  *  This program is free software; you can distribute it and/or modify it
11  *  under the terms of the GNU General Public License (Version 2) as
12  *  published by the Free Software Foundation.
13  *
14  *  This program is distributed in the hope it will be useful, but WITHOUT
15  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
17  *  for more details.
18  *
19  *  You should have received a copy of the GNU General Public License along
20  *  with this program; if not, write to the Free Software Foundation, Inc.,
21  *  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA.
22  *
23  * A complete emulator for MIPS coprocessor 1 instructions.  This is
24  * required for #float(switch) or #float(trap), where it catches all
25  * COP1 instructions via the "CoProcessor Unusable" exception.
26  *
27  * More surprisingly it is also required for #float(ieee), to help out
28  * the hardware FPU at the boundaries of the IEEE-754 representation
29  * (denormalised values, infinities, underflow, etc).  It is made
30  * quite nasty because emulation of some non-COP1 instructions is
31  * required, e.g. in branch delay slots.
32  *
33  * Note if you know that you won't have an FPU, then you'll get much
34  * better performance by compiling with -msoft-float!
35  */
36 #include <linux/sched.h>
37 #include <linux/debugfs.h>
38 #include <linux/percpu-defs.h>
39 #include <linux/perf_event.h>
40 
41 #include <asm/branch.h>
42 #include <asm/inst.h>
43 #include <asm/ptrace.h>
44 #include <asm/signal.h>
45 #include <linux/uaccess.h>
46 
47 #include <asm/cpu-info.h>
48 #include <asm/processor.h>
49 #include <asm/fpu_emulator.h>
50 #include <asm/fpu.h>
51 #include <asm/mips-r2-to-r6-emul.h>
52 
53 #include "ieee754.h"
54 
55 /* Function which emulates a floating point instruction. */
56 
57 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
58 	mips_instruction);
59 
60 static int fpux_emu(struct pt_regs *,
61 	struct mips_fpu_struct *, mips_instruction, void __user **);
62 
63 /* Control registers */
64 
65 #define FPCREG_RID	0	/* $0  = revision id */
66 #define FPCREG_FCCR	25	/* $25 = fccr */
67 #define FPCREG_FEXR	26	/* $26 = fexr */
68 #define FPCREG_FENR	28	/* $28 = fenr */
69 #define FPCREG_CSR	31	/* $31 = csr */
70 
71 /* convert condition code register number to csr bit */
72 const unsigned int fpucondbit[8] = {
73 	FPU_CSR_COND,
74 	FPU_CSR_COND1,
75 	FPU_CSR_COND2,
76 	FPU_CSR_COND3,
77 	FPU_CSR_COND4,
78 	FPU_CSR_COND5,
79 	FPU_CSR_COND6,
80 	FPU_CSR_COND7
81 };
82 
83 /* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
84 static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
85 static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
86 static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
87 static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
88 
89 /*
90  * This functions translates a 32-bit microMIPS instruction
91  * into a 32-bit MIPS32 instruction. Returns 0 on success
92  * and SIGILL otherwise.
93  */
94 static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
95 {
96 	union mips_instruction insn = *insn_ptr;
97 	union mips_instruction mips32_insn = insn;
98 	int func, fmt, op;
99 
100 	switch (insn.mm_i_format.opcode) {
101 	case mm_ldc132_op:
102 		mips32_insn.mm_i_format.opcode = ldc1_op;
103 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
104 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
105 		break;
106 	case mm_lwc132_op:
107 		mips32_insn.mm_i_format.opcode = lwc1_op;
108 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
109 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
110 		break;
111 	case mm_sdc132_op:
112 		mips32_insn.mm_i_format.opcode = sdc1_op;
113 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
114 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
115 		break;
116 	case mm_swc132_op:
117 		mips32_insn.mm_i_format.opcode = swc1_op;
118 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
119 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
120 		break;
121 	case mm_pool32i_op:
122 		/* NOTE: offset is << by 1 if in microMIPS mode. */
123 		if ((insn.mm_i_format.rt == mm_bc1f_op) ||
124 		    (insn.mm_i_format.rt == mm_bc1t_op)) {
125 			mips32_insn.fb_format.opcode = cop1_op;
126 			mips32_insn.fb_format.bc = bc_op;
127 			mips32_insn.fb_format.flag =
128 				(insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
129 		} else
130 			return SIGILL;
131 		break;
132 	case mm_pool32f_op:
133 		switch (insn.mm_fp0_format.func) {
134 		case mm_32f_01_op:
135 		case mm_32f_11_op:
136 		case mm_32f_02_op:
137 		case mm_32f_12_op:
138 		case mm_32f_41_op:
139 		case mm_32f_51_op:
140 		case mm_32f_42_op:
141 		case mm_32f_52_op:
142 			op = insn.mm_fp0_format.func;
143 			if (op == mm_32f_01_op)
144 				func = madd_s_op;
145 			else if (op == mm_32f_11_op)
146 				func = madd_d_op;
147 			else if (op == mm_32f_02_op)
148 				func = nmadd_s_op;
149 			else if (op == mm_32f_12_op)
150 				func = nmadd_d_op;
151 			else if (op == mm_32f_41_op)
152 				func = msub_s_op;
153 			else if (op == mm_32f_51_op)
154 				func = msub_d_op;
155 			else if (op == mm_32f_42_op)
156 				func = nmsub_s_op;
157 			else
158 				func = nmsub_d_op;
159 			mips32_insn.fp6_format.opcode = cop1x_op;
160 			mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
161 			mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
162 			mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
163 			mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
164 			mips32_insn.fp6_format.func = func;
165 			break;
166 		case mm_32f_10_op:
167 			func = -1;	/* Invalid */
168 			op = insn.mm_fp5_format.op & 0x7;
169 			if (op == mm_ldxc1_op)
170 				func = ldxc1_op;
171 			else if (op == mm_sdxc1_op)
172 				func = sdxc1_op;
173 			else if (op == mm_lwxc1_op)
174 				func = lwxc1_op;
175 			else if (op == mm_swxc1_op)
176 				func = swxc1_op;
177 
178 			if (func != -1) {
179 				mips32_insn.r_format.opcode = cop1x_op;
180 				mips32_insn.r_format.rs =
181 					insn.mm_fp5_format.base;
182 				mips32_insn.r_format.rt =
183 					insn.mm_fp5_format.index;
184 				mips32_insn.r_format.rd = 0;
185 				mips32_insn.r_format.re = insn.mm_fp5_format.fd;
186 				mips32_insn.r_format.func = func;
187 			} else
188 				return SIGILL;
189 			break;
190 		case mm_32f_40_op:
191 			op = -1;	/* Invalid */
192 			if (insn.mm_fp2_format.op == mm_fmovt_op)
193 				op = 1;
194 			else if (insn.mm_fp2_format.op == mm_fmovf_op)
195 				op = 0;
196 			if (op != -1) {
197 				mips32_insn.fp0_format.opcode = cop1_op;
198 				mips32_insn.fp0_format.fmt =
199 					sdps_format[insn.mm_fp2_format.fmt];
200 				mips32_insn.fp0_format.ft =
201 					(insn.mm_fp2_format.cc<<2) + op;
202 				mips32_insn.fp0_format.fs =
203 					insn.mm_fp2_format.fs;
204 				mips32_insn.fp0_format.fd =
205 					insn.mm_fp2_format.fd;
206 				mips32_insn.fp0_format.func = fmovc_op;
207 			} else
208 				return SIGILL;
209 			break;
210 		case mm_32f_60_op:
211 			func = -1;	/* Invalid */
212 			if (insn.mm_fp0_format.op == mm_fadd_op)
213 				func = fadd_op;
214 			else if (insn.mm_fp0_format.op == mm_fsub_op)
215 				func = fsub_op;
216 			else if (insn.mm_fp0_format.op == mm_fmul_op)
217 				func = fmul_op;
218 			else if (insn.mm_fp0_format.op == mm_fdiv_op)
219 				func = fdiv_op;
220 			if (func != -1) {
221 				mips32_insn.fp0_format.opcode = cop1_op;
222 				mips32_insn.fp0_format.fmt =
223 					sdps_format[insn.mm_fp0_format.fmt];
224 				mips32_insn.fp0_format.ft =
225 					insn.mm_fp0_format.ft;
226 				mips32_insn.fp0_format.fs =
227 					insn.mm_fp0_format.fs;
228 				mips32_insn.fp0_format.fd =
229 					insn.mm_fp0_format.fd;
230 				mips32_insn.fp0_format.func = func;
231 			} else
232 				return SIGILL;
233 			break;
234 		case mm_32f_70_op:
235 			func = -1;	/* Invalid */
236 			if (insn.mm_fp0_format.op == mm_fmovn_op)
237 				func = fmovn_op;
238 			else if (insn.mm_fp0_format.op == mm_fmovz_op)
239 				func = fmovz_op;
240 			if (func != -1) {
241 				mips32_insn.fp0_format.opcode = cop1_op;
242 				mips32_insn.fp0_format.fmt =
243 					sdps_format[insn.mm_fp0_format.fmt];
244 				mips32_insn.fp0_format.ft =
245 					insn.mm_fp0_format.ft;
246 				mips32_insn.fp0_format.fs =
247 					insn.mm_fp0_format.fs;
248 				mips32_insn.fp0_format.fd =
249 					insn.mm_fp0_format.fd;
250 				mips32_insn.fp0_format.func = func;
251 			} else
252 				return SIGILL;
253 			break;
254 		case mm_32f_73_op:    /* POOL32FXF */
255 			switch (insn.mm_fp1_format.op) {
256 			case mm_movf0_op:
257 			case mm_movf1_op:
258 			case mm_movt0_op:
259 			case mm_movt1_op:
260 				if ((insn.mm_fp1_format.op & 0x7f) ==
261 				    mm_movf0_op)
262 					op = 0;
263 				else
264 					op = 1;
265 				mips32_insn.r_format.opcode = spec_op;
266 				mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
267 				mips32_insn.r_format.rt =
268 					(insn.mm_fp4_format.cc << 2) + op;
269 				mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
270 				mips32_insn.r_format.re = 0;
271 				mips32_insn.r_format.func = movc_op;
272 				break;
273 			case mm_fcvtd0_op:
274 			case mm_fcvtd1_op:
275 			case mm_fcvts0_op:
276 			case mm_fcvts1_op:
277 				if ((insn.mm_fp1_format.op & 0x7f) ==
278 				    mm_fcvtd0_op) {
279 					func = fcvtd_op;
280 					fmt = swl_format[insn.mm_fp3_format.fmt];
281 				} else {
282 					func = fcvts_op;
283 					fmt = dwl_format[insn.mm_fp3_format.fmt];
284 				}
285 				mips32_insn.fp0_format.opcode = cop1_op;
286 				mips32_insn.fp0_format.fmt = fmt;
287 				mips32_insn.fp0_format.ft = 0;
288 				mips32_insn.fp0_format.fs =
289 					insn.mm_fp3_format.fs;
290 				mips32_insn.fp0_format.fd =
291 					insn.mm_fp3_format.rt;
292 				mips32_insn.fp0_format.func = func;
293 				break;
294 			case mm_fmov0_op:
295 			case mm_fmov1_op:
296 			case mm_fabs0_op:
297 			case mm_fabs1_op:
298 			case mm_fneg0_op:
299 			case mm_fneg1_op:
300 				if ((insn.mm_fp1_format.op & 0x7f) ==
301 				    mm_fmov0_op)
302 					func = fmov_op;
303 				else if ((insn.mm_fp1_format.op & 0x7f) ==
304 					 mm_fabs0_op)
305 					func = fabs_op;
306 				else
307 					func = fneg_op;
308 				mips32_insn.fp0_format.opcode = cop1_op;
309 				mips32_insn.fp0_format.fmt =
310 					sdps_format[insn.mm_fp3_format.fmt];
311 				mips32_insn.fp0_format.ft = 0;
312 				mips32_insn.fp0_format.fs =
313 					insn.mm_fp3_format.fs;
314 				mips32_insn.fp0_format.fd =
315 					insn.mm_fp3_format.rt;
316 				mips32_insn.fp0_format.func = func;
317 				break;
318 			case mm_ffloorl_op:
319 			case mm_ffloorw_op:
320 			case mm_fceill_op:
321 			case mm_fceilw_op:
322 			case mm_ftruncl_op:
323 			case mm_ftruncw_op:
324 			case mm_froundl_op:
325 			case mm_froundw_op:
326 			case mm_fcvtl_op:
327 			case mm_fcvtw_op:
328 				if (insn.mm_fp1_format.op == mm_ffloorl_op)
329 					func = ffloorl_op;
330 				else if (insn.mm_fp1_format.op == mm_ffloorw_op)
331 					func = ffloor_op;
332 				else if (insn.mm_fp1_format.op == mm_fceill_op)
333 					func = fceill_op;
334 				else if (insn.mm_fp1_format.op == mm_fceilw_op)
335 					func = fceil_op;
336 				else if (insn.mm_fp1_format.op == mm_ftruncl_op)
337 					func = ftruncl_op;
338 				else if (insn.mm_fp1_format.op == mm_ftruncw_op)
339 					func = ftrunc_op;
340 				else if (insn.mm_fp1_format.op == mm_froundl_op)
341 					func = froundl_op;
342 				else if (insn.mm_fp1_format.op == mm_froundw_op)
343 					func = fround_op;
344 				else if (insn.mm_fp1_format.op == mm_fcvtl_op)
345 					func = fcvtl_op;
346 				else
347 					func = fcvtw_op;
348 				mips32_insn.fp0_format.opcode = cop1_op;
349 				mips32_insn.fp0_format.fmt =
350 					sd_format[insn.mm_fp1_format.fmt];
351 				mips32_insn.fp0_format.ft = 0;
352 				mips32_insn.fp0_format.fs =
353 					insn.mm_fp1_format.fs;
354 				mips32_insn.fp0_format.fd =
355 					insn.mm_fp1_format.rt;
356 				mips32_insn.fp0_format.func = func;
357 				break;
358 			case mm_frsqrt_op:
359 			case mm_fsqrt_op:
360 			case mm_frecip_op:
361 				if (insn.mm_fp1_format.op == mm_frsqrt_op)
362 					func = frsqrt_op;
363 				else if (insn.mm_fp1_format.op == mm_fsqrt_op)
364 					func = fsqrt_op;
365 				else
366 					func = frecip_op;
367 				mips32_insn.fp0_format.opcode = cop1_op;
368 				mips32_insn.fp0_format.fmt =
369 					sdps_format[insn.mm_fp1_format.fmt];
370 				mips32_insn.fp0_format.ft = 0;
371 				mips32_insn.fp0_format.fs =
372 					insn.mm_fp1_format.fs;
373 				mips32_insn.fp0_format.fd =
374 					insn.mm_fp1_format.rt;
375 				mips32_insn.fp0_format.func = func;
376 				break;
377 			case mm_mfc1_op:
378 			case mm_mtc1_op:
379 			case mm_cfc1_op:
380 			case mm_ctc1_op:
381 			case mm_mfhc1_op:
382 			case mm_mthc1_op:
383 				if (insn.mm_fp1_format.op == mm_mfc1_op)
384 					op = mfc_op;
385 				else if (insn.mm_fp1_format.op == mm_mtc1_op)
386 					op = mtc_op;
387 				else if (insn.mm_fp1_format.op == mm_cfc1_op)
388 					op = cfc_op;
389 				else if (insn.mm_fp1_format.op == mm_ctc1_op)
390 					op = ctc_op;
391 				else if (insn.mm_fp1_format.op == mm_mfhc1_op)
392 					op = mfhc_op;
393 				else
394 					op = mthc_op;
395 				mips32_insn.fp1_format.opcode = cop1_op;
396 				mips32_insn.fp1_format.op = op;
397 				mips32_insn.fp1_format.rt =
398 					insn.mm_fp1_format.rt;
399 				mips32_insn.fp1_format.fs =
400 					insn.mm_fp1_format.fs;
401 				mips32_insn.fp1_format.fd = 0;
402 				mips32_insn.fp1_format.func = 0;
403 				break;
404 			default:
405 				return SIGILL;
406 			}
407 			break;
408 		case mm_32f_74_op:	/* c.cond.fmt */
409 			mips32_insn.fp0_format.opcode = cop1_op;
410 			mips32_insn.fp0_format.fmt =
411 				sdps_format[insn.mm_fp4_format.fmt];
412 			mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
413 			mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
414 			mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
415 			mips32_insn.fp0_format.func =
416 				insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
417 			break;
418 		default:
419 			return SIGILL;
420 		}
421 		break;
422 	default:
423 		return SIGILL;
424 	}
425 
426 	*insn_ptr = mips32_insn;
427 	return 0;
428 }
429 
430 /*
431  * Redundant with logic already in kernel/branch.c,
432  * embedded in compute_return_epc.  At some point,
433  * a single subroutine should be used across both
434  * modules.
435  */
436 int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
437 		  unsigned long *contpc)
438 {
439 	union mips_instruction insn = (union mips_instruction)dec_insn.insn;
440 	unsigned int fcr31;
441 	unsigned int bit = 0;
442 	unsigned int bit0;
443 	union fpureg *fpr;
444 
445 	switch (insn.i_format.opcode) {
446 	case spec_op:
447 		switch (insn.r_format.func) {
448 		case jalr_op:
449 			if (insn.r_format.rd != 0) {
450 				regs->regs[insn.r_format.rd] =
451 					regs->cp0_epc + dec_insn.pc_inc +
452 					dec_insn.next_pc_inc;
453 			}
454 			/* fall through */
455 		case jr_op:
456 			/* For R6, JR already emulated in jalr_op */
457 			if (NO_R6EMU && insn.r_format.func == jr_op)
458 				break;
459 			*contpc = regs->regs[insn.r_format.rs];
460 			return 1;
461 		}
462 		break;
463 	case bcond_op:
464 		switch (insn.i_format.rt) {
465 		case bltzal_op:
466 		case bltzall_op:
467 			if (NO_R6EMU && (insn.i_format.rs ||
468 			    insn.i_format.rt == bltzall_op))
469 				break;
470 
471 			regs->regs[31] = regs->cp0_epc +
472 				dec_insn.pc_inc +
473 				dec_insn.next_pc_inc;
474 			/* fall through */
475 		case bltzl_op:
476 			if (NO_R6EMU)
477 				break;
478 			/* fall through */
479 		case bltz_op:
480 			if ((long)regs->regs[insn.i_format.rs] < 0)
481 				*contpc = regs->cp0_epc +
482 					dec_insn.pc_inc +
483 					(insn.i_format.simmediate << 2);
484 			else
485 				*contpc = regs->cp0_epc +
486 					dec_insn.pc_inc +
487 					dec_insn.next_pc_inc;
488 			return 1;
489 		case bgezal_op:
490 		case bgezall_op:
491 			if (NO_R6EMU && (insn.i_format.rs ||
492 			    insn.i_format.rt == bgezall_op))
493 				break;
494 
495 			regs->regs[31] = regs->cp0_epc +
496 				dec_insn.pc_inc +
497 				dec_insn.next_pc_inc;
498 			/* fall through */
499 		case bgezl_op:
500 			if (NO_R6EMU)
501 				break;
502 			/* fall through */
503 		case bgez_op:
504 			if ((long)regs->regs[insn.i_format.rs] >= 0)
505 				*contpc = regs->cp0_epc +
506 					dec_insn.pc_inc +
507 					(insn.i_format.simmediate << 2);
508 			else
509 				*contpc = regs->cp0_epc +
510 					dec_insn.pc_inc +
511 					dec_insn.next_pc_inc;
512 			return 1;
513 		}
514 		break;
515 	case jalx_op:
516 		set_isa16_mode(bit);
517 		/* fall through */
518 	case jal_op:
519 		regs->regs[31] = regs->cp0_epc +
520 			dec_insn.pc_inc +
521 			dec_insn.next_pc_inc;
522 		/* fall through */
523 	case j_op:
524 		*contpc = regs->cp0_epc + dec_insn.pc_inc;
525 		*contpc >>= 28;
526 		*contpc <<= 28;
527 		*contpc |= (insn.j_format.target << 2);
528 		/* Set microMIPS mode bit: XOR for jalx. */
529 		*contpc ^= bit;
530 		return 1;
531 	case beql_op:
532 		if (NO_R6EMU)
533 			break;
534 		/* fall through */
535 	case beq_op:
536 		if (regs->regs[insn.i_format.rs] ==
537 		    regs->regs[insn.i_format.rt])
538 			*contpc = regs->cp0_epc +
539 				dec_insn.pc_inc +
540 				(insn.i_format.simmediate << 2);
541 		else
542 			*contpc = regs->cp0_epc +
543 				dec_insn.pc_inc +
544 				dec_insn.next_pc_inc;
545 		return 1;
546 	case bnel_op:
547 		if (NO_R6EMU)
548 			break;
549 		/* fall through */
550 	case bne_op:
551 		if (regs->regs[insn.i_format.rs] !=
552 		    regs->regs[insn.i_format.rt])
553 			*contpc = regs->cp0_epc +
554 				dec_insn.pc_inc +
555 				(insn.i_format.simmediate << 2);
556 		else
557 			*contpc = regs->cp0_epc +
558 				dec_insn.pc_inc +
559 				dec_insn.next_pc_inc;
560 		return 1;
561 	case blezl_op:
562 		if (!insn.i_format.rt && NO_R6EMU)
563 			break;
564 		/* fall through */
565 	case blez_op:
566 
567 		/*
568 		 * Compact branches for R6 for the
569 		 * blez and blezl opcodes.
570 		 * BLEZ  | rs = 0 | rt != 0  == BLEZALC
571 		 * BLEZ  | rs = rt != 0      == BGEZALC
572 		 * BLEZ  | rs != 0 | rt != 0 == BGEUC
573 		 * BLEZL | rs = 0 | rt != 0  == BLEZC
574 		 * BLEZL | rs = rt != 0      == BGEZC
575 		 * BLEZL | rs != 0 | rt != 0 == BGEC
576 		 *
577 		 * For real BLEZ{,L}, rt is always 0.
578 		 */
579 		if (cpu_has_mips_r6 && insn.i_format.rt) {
580 			if ((insn.i_format.opcode == blez_op) &&
581 			    ((!insn.i_format.rs && insn.i_format.rt) ||
582 			     (insn.i_format.rs == insn.i_format.rt)))
583 				regs->regs[31] = regs->cp0_epc +
584 					dec_insn.pc_inc;
585 			*contpc = regs->cp0_epc + dec_insn.pc_inc +
586 				dec_insn.next_pc_inc;
587 
588 			return 1;
589 		}
590 		if ((long)regs->regs[insn.i_format.rs] <= 0)
591 			*contpc = regs->cp0_epc +
592 				dec_insn.pc_inc +
593 				(insn.i_format.simmediate << 2);
594 		else
595 			*contpc = regs->cp0_epc +
596 				dec_insn.pc_inc +
597 				dec_insn.next_pc_inc;
598 		return 1;
599 	case bgtzl_op:
600 		if (!insn.i_format.rt && NO_R6EMU)
601 			break;
602 		/* fall through */
603 	case bgtz_op:
604 		/*
605 		 * Compact branches for R6 for the
606 		 * bgtz and bgtzl opcodes.
607 		 * BGTZ  | rs = 0 | rt != 0  == BGTZALC
608 		 * BGTZ  | rs = rt != 0      == BLTZALC
609 		 * BGTZ  | rs != 0 | rt != 0 == BLTUC
610 		 * BGTZL | rs = 0 | rt != 0  == BGTZC
611 		 * BGTZL | rs = rt != 0      == BLTZC
612 		 * BGTZL | rs != 0 | rt != 0 == BLTC
613 		 *
614 		 * *ZALC varint for BGTZ &&& rt != 0
615 		 * For real GTZ{,L}, rt is always 0.
616 		 */
617 		if (cpu_has_mips_r6 && insn.i_format.rt) {
618 			if ((insn.i_format.opcode == blez_op) &&
619 			    ((!insn.i_format.rs && insn.i_format.rt) ||
620 			     (insn.i_format.rs == insn.i_format.rt)))
621 				regs->regs[31] = regs->cp0_epc +
622 					dec_insn.pc_inc;
623 			*contpc = regs->cp0_epc + dec_insn.pc_inc +
624 				dec_insn.next_pc_inc;
625 
626 			return 1;
627 		}
628 
629 		if ((long)regs->regs[insn.i_format.rs] > 0)
630 			*contpc = regs->cp0_epc +
631 				dec_insn.pc_inc +
632 				(insn.i_format.simmediate << 2);
633 		else
634 			*contpc = regs->cp0_epc +
635 				dec_insn.pc_inc +
636 				dec_insn.next_pc_inc;
637 		return 1;
638 	case pop10_op:
639 	case pop30_op:
640 		if (!cpu_has_mips_r6)
641 			break;
642 		if (insn.i_format.rt && !insn.i_format.rs)
643 			regs->regs[31] = regs->cp0_epc + 4;
644 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
645 			dec_insn.next_pc_inc;
646 
647 		return 1;
648 #ifdef CONFIG_CPU_CAVIUM_OCTEON
649 	case lwc2_op: /* This is bbit0 on Octeon */
650 		if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
651 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
652 		else
653 			*contpc = regs->cp0_epc + 8;
654 		return 1;
655 	case ldc2_op: /* This is bbit032 on Octeon */
656 		if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
657 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
658 		else
659 			*contpc = regs->cp0_epc + 8;
660 		return 1;
661 	case swc2_op: /* This is bbit1 on Octeon */
662 		if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
663 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
664 		else
665 			*contpc = regs->cp0_epc + 8;
666 		return 1;
667 	case sdc2_op: /* This is bbit132 on Octeon */
668 		if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
669 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
670 		else
671 			*contpc = regs->cp0_epc + 8;
672 		return 1;
673 #else
674 	case bc6_op:
675 		/*
676 		 * Only valid for MIPS R6 but we can still end up
677 		 * here from a broken userland so just tell emulator
678 		 * this is not a branch and let it break later on.
679 		 */
680 		if  (!cpu_has_mips_r6)
681 			break;
682 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
683 			dec_insn.next_pc_inc;
684 
685 		return 1;
686 	case balc6_op:
687 		if (!cpu_has_mips_r6)
688 			break;
689 		regs->regs[31] = regs->cp0_epc + 4;
690 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
691 			dec_insn.next_pc_inc;
692 
693 		return 1;
694 	case pop66_op:
695 		if (!cpu_has_mips_r6)
696 			break;
697 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
698 			dec_insn.next_pc_inc;
699 
700 		return 1;
701 	case pop76_op:
702 		if (!cpu_has_mips_r6)
703 			break;
704 		if (!insn.i_format.rs)
705 			regs->regs[31] = regs->cp0_epc + 4;
706 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
707 			dec_insn.next_pc_inc;
708 
709 		return 1;
710 #endif
711 	case cop0_op:
712 	case cop1_op:
713 		/* Need to check for R6 bc1nez and bc1eqz branches */
714 		if (cpu_has_mips_r6 &&
715 		    ((insn.i_format.rs == bc1eqz_op) ||
716 		     (insn.i_format.rs == bc1nez_op))) {
717 			bit = 0;
718 			fpr = &current->thread.fpu.fpr[insn.i_format.rt];
719 			bit0 = get_fpr32(fpr, 0) & 0x1;
720 			switch (insn.i_format.rs) {
721 			case bc1eqz_op:
722 				bit = bit0 == 0;
723 				break;
724 			case bc1nez_op:
725 				bit = bit0 != 0;
726 				break;
727 			}
728 			if (bit)
729 				*contpc = regs->cp0_epc +
730 					dec_insn.pc_inc +
731 					(insn.i_format.simmediate << 2);
732 			else
733 				*contpc = regs->cp0_epc +
734 					dec_insn.pc_inc +
735 					dec_insn.next_pc_inc;
736 
737 			return 1;
738 		}
739 		/* R2/R6 compatible cop1 instruction */
740 		/* fall through */
741 	case cop2_op:
742 	case cop1x_op:
743 		if (insn.i_format.rs == bc_op) {
744 			preempt_disable();
745 			if (is_fpu_owner())
746 			        fcr31 = read_32bit_cp1_register(CP1_STATUS);
747 			else
748 				fcr31 = current->thread.fpu.fcr31;
749 			preempt_enable();
750 
751 			bit = (insn.i_format.rt >> 2);
752 			bit += (bit != 0);
753 			bit += 23;
754 			switch (insn.i_format.rt & 3) {
755 			case 0:	/* bc1f */
756 			case 2:	/* bc1fl */
757 				if (~fcr31 & (1 << bit))
758 					*contpc = regs->cp0_epc +
759 						dec_insn.pc_inc +
760 						(insn.i_format.simmediate << 2);
761 				else
762 					*contpc = regs->cp0_epc +
763 						dec_insn.pc_inc +
764 						dec_insn.next_pc_inc;
765 				return 1;
766 			case 1:	/* bc1t */
767 			case 3:	/* bc1tl */
768 				if (fcr31 & (1 << bit))
769 					*contpc = regs->cp0_epc +
770 						dec_insn.pc_inc +
771 						(insn.i_format.simmediate << 2);
772 				else
773 					*contpc = regs->cp0_epc +
774 						dec_insn.pc_inc +
775 						dec_insn.next_pc_inc;
776 				return 1;
777 			}
778 		}
779 		break;
780 	}
781 	return 0;
782 }
783 
784 /*
785  * In the Linux kernel, we support selection of FPR format on the
786  * basis of the Status.FR bit.	If an FPU is not present, the FR bit
787  * is hardwired to zero, which would imply a 32-bit FPU even for
788  * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
789  * FPU emu is slow and bulky and optimizing this function offers fairly
790  * sizeable benefits so we try to be clever and make this function return
791  * a constant whenever possible, that is on 64-bit kernels without O32
792  * compatibility enabled and on 32-bit without 64-bit FPU support.
793  */
794 static inline int cop1_64bit(struct pt_regs *xcp)
795 {
796 	if (IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_MIPS32_O32))
797 		return 1;
798 	else if (IS_ENABLED(CONFIG_32BIT) &&
799 		 !IS_ENABLED(CONFIG_MIPS_O32_FP64_SUPPORT))
800 		return 0;
801 
802 	return !test_thread_flag(TIF_32BIT_FPREGS);
803 }
804 
805 static inline bool hybrid_fprs(void)
806 {
807 	return test_thread_flag(TIF_HYBRID_FPREGS);
808 }
809 
810 #define SIFROMREG(si, x)						\
811 do {									\
812 	if (cop1_64bit(xcp) && !hybrid_fprs())				\
813 		(si) = (int)get_fpr32(&ctx->fpr[x], 0);			\
814 	else								\
815 		(si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1);	\
816 } while (0)
817 
818 #define SITOREG(si, x)							\
819 do {									\
820 	if (cop1_64bit(xcp) && !hybrid_fprs()) {			\
821 		unsigned int i;						\
822 		set_fpr32(&ctx->fpr[x], 0, si);				\
823 		for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)	\
824 			set_fpr32(&ctx->fpr[x], i, 0);			\
825 	} else {							\
826 		set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si);		\
827 	}								\
828 } while (0)
829 
830 #define SIFROMHREG(si, x)	((si) = (int)get_fpr32(&ctx->fpr[x], 1))
831 
832 #define SITOHREG(si, x)							\
833 do {									\
834 	unsigned int i;							\
835 	set_fpr32(&ctx->fpr[x], 1, si);					\
836 	for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)		\
837 		set_fpr32(&ctx->fpr[x], i, 0);				\
838 } while (0)
839 
840 #define DIFROMREG(di, x)						\
841 	((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) ^ 1)], 0))
842 
843 #define DITOREG(di, x)							\
844 do {									\
845 	unsigned int fpr, i;						\
846 	fpr = (x) & ~(cop1_64bit(xcp) ^ 1);				\
847 	set_fpr64(&ctx->fpr[fpr], 0, di);				\
848 	for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++)		\
849 		set_fpr64(&ctx->fpr[fpr], i, 0);			\
850 } while (0)
851 
852 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
853 #define SPTOREG(sp, x)	SITOREG((sp).bits, x)
854 #define DPFROMREG(dp, x)	DIFROMREG((dp).bits, x)
855 #define DPTOREG(dp, x)	DITOREG((dp).bits, x)
856 
857 /*
858  * Emulate a CFC1 instruction.
859  */
860 static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
861 			    mips_instruction ir)
862 {
863 	u32 fcr31 = ctx->fcr31;
864 	u32 value = 0;
865 
866 	switch (MIPSInst_RD(ir)) {
867 	case FPCREG_CSR:
868 		value = fcr31;
869 		pr_debug("%p gpr[%d]<-csr=%08x\n",
870 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
871 		break;
872 
873 	case FPCREG_FENR:
874 		if (!cpu_has_mips_r)
875 			break;
876 		value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
877 			MIPS_FENR_FS;
878 		value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM);
879 		pr_debug("%p gpr[%d]<-enr=%08x\n",
880 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
881 		break;
882 
883 	case FPCREG_FEXR:
884 		if (!cpu_has_mips_r)
885 			break;
886 		value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
887 		pr_debug("%p gpr[%d]<-exr=%08x\n",
888 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
889 		break;
890 
891 	case FPCREG_FCCR:
892 		if (!cpu_has_mips_r)
893 			break;
894 		value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
895 			MIPS_FCCR_COND0;
896 		value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
897 			 (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0);
898 		pr_debug("%p gpr[%d]<-ccr=%08x\n",
899 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
900 		break;
901 
902 	case FPCREG_RID:
903 		value = boot_cpu_data.fpu_id;
904 		break;
905 
906 	default:
907 		break;
908 	}
909 
910 	if (MIPSInst_RT(ir))
911 		xcp->regs[MIPSInst_RT(ir)] = value;
912 }
913 
914 /*
915  * Emulate a CTC1 instruction.
916  */
917 static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
918 			    mips_instruction ir)
919 {
920 	u32 fcr31 = ctx->fcr31;
921 	u32 value;
922 	u32 mask;
923 
924 	if (MIPSInst_RT(ir) == 0)
925 		value = 0;
926 	else
927 		value = xcp->regs[MIPSInst_RT(ir)];
928 
929 	switch (MIPSInst_RD(ir)) {
930 	case FPCREG_CSR:
931 		pr_debug("%p gpr[%d]->csr=%08x\n",
932 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
933 
934 		/* Preserve read-only bits.  */
935 		mask = boot_cpu_data.fpu_msk31;
936 		fcr31 = (value & ~mask) | (fcr31 & mask);
937 		break;
938 
939 	case FPCREG_FENR:
940 		if (!cpu_has_mips_r)
941 			break;
942 		pr_debug("%p gpr[%d]->enr=%08x\n",
943 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
944 		fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM);
945 		fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
946 			 FPU_CSR_FS;
947 		fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM);
948 		break;
949 
950 	case FPCREG_FEXR:
951 		if (!cpu_has_mips_r)
952 			break;
953 		pr_debug("%p gpr[%d]->exr=%08x\n",
954 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
955 		fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S);
956 		fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
957 		break;
958 
959 	case FPCREG_FCCR:
960 		if (!cpu_has_mips_r)
961 			break;
962 		pr_debug("%p gpr[%d]->ccr=%08x\n",
963 			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
964 		fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND);
965 		fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
966 			 FPU_CSR_COND;
967 		fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
968 			 FPU_CSR_CONDX;
969 		break;
970 
971 	default:
972 		break;
973 	}
974 
975 	ctx->fcr31 = fcr31;
976 }
977 
978 /*
979  * Emulate the single floating point instruction pointed at by EPC.
980  * Two instructions if the instruction is in a branch delay slot.
981  */
982 
983 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
984 		struct mm_decoded_insn dec_insn, void __user **fault_addr)
985 {
986 	unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
987 	unsigned int cond, cbit, bit0;
988 	mips_instruction ir;
989 	int likely, pc_inc;
990 	union fpureg *fpr;
991 	u32 __user *wva;
992 	u64 __user *dva;
993 	u32 wval;
994 	u64 dval;
995 	int sig;
996 
997 	/*
998 	 * These are giving gcc a gentle hint about what to expect in
999 	 * dec_inst in order to do better optimization.
1000 	 */
1001 	if (!cpu_has_mmips && dec_insn.micro_mips_mode)
1002 		unreachable();
1003 
1004 	/* XXX NEC Vr54xx bug workaround */
1005 	if (delay_slot(xcp)) {
1006 		if (dec_insn.micro_mips_mode) {
1007 			if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
1008 				clear_delay_slot(xcp);
1009 		} else {
1010 			if (!isBranchInstr(xcp, dec_insn, &contpc))
1011 				clear_delay_slot(xcp);
1012 		}
1013 	}
1014 
1015 	if (delay_slot(xcp)) {
1016 		/*
1017 		 * The instruction to be emulated is in a branch delay slot
1018 		 * which means that we have to	emulate the branch instruction
1019 		 * BEFORE we do the cop1 instruction.
1020 		 *
1021 		 * This branch could be a COP1 branch, but in that case we
1022 		 * would have had a trap for that instruction, and would not
1023 		 * come through this route.
1024 		 *
1025 		 * Linux MIPS branch emulator operates on context, updating the
1026 		 * cp0_epc.
1027 		 */
1028 		ir = dec_insn.next_insn;  /* process delay slot instr */
1029 		pc_inc = dec_insn.next_pc_inc;
1030 	} else {
1031 		ir = dec_insn.insn;       /* process current instr */
1032 		pc_inc = dec_insn.pc_inc;
1033 	}
1034 
1035 	/*
1036 	 * Since microMIPS FPU instructios are a subset of MIPS32 FPU
1037 	 * instructions, we want to convert microMIPS FPU instructions
1038 	 * into MIPS32 instructions so that we could reuse all of the
1039 	 * FPU emulation code.
1040 	 *
1041 	 * NOTE: We cannot do this for branch instructions since they
1042 	 *       are not a subset. Example: Cannot emulate a 16-bit
1043 	 *       aligned target address with a MIPS32 instruction.
1044 	 */
1045 	if (dec_insn.micro_mips_mode) {
1046 		/*
1047 		 * If next instruction is a 16-bit instruction, then it
1048 		 * it cannot be a FPU instruction. This could happen
1049 		 * since we can be called for non-FPU instructions.
1050 		 */
1051 		if ((pc_inc == 2) ||
1052 			(microMIPS32_to_MIPS32((union mips_instruction *)&ir)
1053 			 == SIGILL))
1054 			return SIGILL;
1055 	}
1056 
1057 emul:
1058 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
1059 	MIPS_FPU_EMU_INC_STATS(emulated);
1060 	switch (MIPSInst_OPCODE(ir)) {
1061 	case ldc1_op:
1062 		dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1063 				     MIPSInst_SIMM(ir));
1064 		MIPS_FPU_EMU_INC_STATS(loads);
1065 
1066 		if (!access_ok(dva, sizeof(u64))) {
1067 			MIPS_FPU_EMU_INC_STATS(errors);
1068 			*fault_addr = dva;
1069 			return SIGBUS;
1070 		}
1071 		if (__get_user(dval, dva)) {
1072 			MIPS_FPU_EMU_INC_STATS(errors);
1073 			*fault_addr = dva;
1074 			return SIGSEGV;
1075 		}
1076 		DITOREG(dval, MIPSInst_RT(ir));
1077 		break;
1078 
1079 	case sdc1_op:
1080 		dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1081 				      MIPSInst_SIMM(ir));
1082 		MIPS_FPU_EMU_INC_STATS(stores);
1083 		DIFROMREG(dval, MIPSInst_RT(ir));
1084 		if (!access_ok(dva, sizeof(u64))) {
1085 			MIPS_FPU_EMU_INC_STATS(errors);
1086 			*fault_addr = dva;
1087 			return SIGBUS;
1088 		}
1089 		if (__put_user(dval, dva)) {
1090 			MIPS_FPU_EMU_INC_STATS(errors);
1091 			*fault_addr = dva;
1092 			return SIGSEGV;
1093 		}
1094 		break;
1095 
1096 	case lwc1_op:
1097 		wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1098 				      MIPSInst_SIMM(ir));
1099 		MIPS_FPU_EMU_INC_STATS(loads);
1100 		if (!access_ok(wva, sizeof(u32))) {
1101 			MIPS_FPU_EMU_INC_STATS(errors);
1102 			*fault_addr = wva;
1103 			return SIGBUS;
1104 		}
1105 		if (__get_user(wval, wva)) {
1106 			MIPS_FPU_EMU_INC_STATS(errors);
1107 			*fault_addr = wva;
1108 			return SIGSEGV;
1109 		}
1110 		SITOREG(wval, MIPSInst_RT(ir));
1111 		break;
1112 
1113 	case swc1_op:
1114 		wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1115 				      MIPSInst_SIMM(ir));
1116 		MIPS_FPU_EMU_INC_STATS(stores);
1117 		SIFROMREG(wval, MIPSInst_RT(ir));
1118 		if (!access_ok(wva, sizeof(u32))) {
1119 			MIPS_FPU_EMU_INC_STATS(errors);
1120 			*fault_addr = wva;
1121 			return SIGBUS;
1122 		}
1123 		if (__put_user(wval, wva)) {
1124 			MIPS_FPU_EMU_INC_STATS(errors);
1125 			*fault_addr = wva;
1126 			return SIGSEGV;
1127 		}
1128 		break;
1129 
1130 	case cop1_op:
1131 		switch (MIPSInst_RS(ir)) {
1132 		case dmfc_op:
1133 			if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1134 				return SIGILL;
1135 
1136 			/* copregister fs -> gpr[rt] */
1137 			if (MIPSInst_RT(ir) != 0) {
1138 				DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1139 					MIPSInst_RD(ir));
1140 			}
1141 			break;
1142 
1143 		case dmtc_op:
1144 			if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1145 				return SIGILL;
1146 
1147 			/* copregister fs <- rt */
1148 			DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1149 			break;
1150 
1151 		case mfhc_op:
1152 			if (!cpu_has_mips_r2_r6)
1153 				return SIGILL;
1154 
1155 			/* copregister rd -> gpr[rt] */
1156 			if (MIPSInst_RT(ir) != 0) {
1157 				SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
1158 					MIPSInst_RD(ir));
1159 			}
1160 			break;
1161 
1162 		case mthc_op:
1163 			if (!cpu_has_mips_r2_r6)
1164 				return SIGILL;
1165 
1166 			/* copregister rd <- gpr[rt] */
1167 			SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1168 			break;
1169 
1170 		case mfc_op:
1171 			/* copregister rd -> gpr[rt] */
1172 			if (MIPSInst_RT(ir) != 0) {
1173 				SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1174 					MIPSInst_RD(ir));
1175 			}
1176 			break;
1177 
1178 		case mtc_op:
1179 			/* copregister rd <- rt */
1180 			SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1181 			break;
1182 
1183 		case cfc_op:
1184 			/* cop control register rd -> gpr[rt] */
1185 			cop1_cfc(xcp, ctx, ir);
1186 			break;
1187 
1188 		case ctc_op:
1189 			/* copregister rd <- rt */
1190 			cop1_ctc(xcp, ctx, ir);
1191 			if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1192 				return SIGFPE;
1193 			}
1194 			break;
1195 
1196 		case bc1eqz_op:
1197 		case bc1nez_op:
1198 			if (!cpu_has_mips_r6 || delay_slot(xcp))
1199 				return SIGILL;
1200 
1201 			likely = 0;
1202 			cond = 0;
1203 			fpr = &current->thread.fpu.fpr[MIPSInst_RT(ir)];
1204 			bit0 = get_fpr32(fpr, 0) & 0x1;
1205 			switch (MIPSInst_RS(ir)) {
1206 			case bc1eqz_op:
1207 				MIPS_FPU_EMU_INC_STATS(bc1eqz);
1208 				cond = bit0 == 0;
1209 				break;
1210 			case bc1nez_op:
1211 				MIPS_FPU_EMU_INC_STATS(bc1nez);
1212 				cond = bit0 != 0;
1213 				break;
1214 			}
1215 			goto branch_common;
1216 
1217 		case bc_op:
1218 			if (delay_slot(xcp))
1219 				return SIGILL;
1220 
1221 			if (cpu_has_mips_4_5_r)
1222 				cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
1223 			else
1224 				cbit = FPU_CSR_COND;
1225 			cond = ctx->fcr31 & cbit;
1226 
1227 			likely = 0;
1228 			switch (MIPSInst_RT(ir) & 3) {
1229 			case bcfl_op:
1230 				if (cpu_has_mips_2_3_4_5_r)
1231 					likely = 1;
1232 				/* fall through */
1233 			case bcf_op:
1234 				cond = !cond;
1235 				break;
1236 			case bctl_op:
1237 				if (cpu_has_mips_2_3_4_5_r)
1238 					likely = 1;
1239 				/* fall through */
1240 			case bct_op:
1241 				break;
1242 			}
1243 branch_common:
1244 			MIPS_FPU_EMU_INC_STATS(branches);
1245 			set_delay_slot(xcp);
1246 			if (cond) {
1247 				/*
1248 				 * Branch taken: emulate dslot instruction
1249 				 */
1250 				unsigned long bcpc;
1251 
1252 				/*
1253 				 * Remember EPC at the branch to point back
1254 				 * at so that any delay-slot instruction
1255 				 * signal is not silently ignored.
1256 				 */
1257 				bcpc = xcp->cp0_epc;
1258 				xcp->cp0_epc += dec_insn.pc_inc;
1259 
1260 				contpc = MIPSInst_SIMM(ir);
1261 				ir = dec_insn.next_insn;
1262 				if (dec_insn.micro_mips_mode) {
1263 					contpc = (xcp->cp0_epc + (contpc << 1));
1264 
1265 					/* If 16-bit instruction, not FPU. */
1266 					if ((dec_insn.next_pc_inc == 2) ||
1267 						(microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
1268 
1269 						/*
1270 						 * Since this instruction will
1271 						 * be put on the stack with
1272 						 * 32-bit words, get around
1273 						 * this problem by putting a
1274 						 * NOP16 as the second one.
1275 						 */
1276 						if (dec_insn.next_pc_inc == 2)
1277 							ir = (ir & (~0xffff)) | MM_NOP16;
1278 
1279 						/*
1280 						 * Single step the non-CP1
1281 						 * instruction in the dslot.
1282 						 */
1283 						sig = mips_dsemul(xcp, ir,
1284 								  bcpc, contpc);
1285 						if (sig < 0)
1286 							break;
1287 						if (sig)
1288 							xcp->cp0_epc = bcpc;
1289 						/*
1290 						 * SIGILL forces out of
1291 						 * the emulation loop.
1292 						 */
1293 						return sig ? sig : SIGILL;
1294 					}
1295 				} else
1296 					contpc = (xcp->cp0_epc + (contpc << 2));
1297 
1298 				switch (MIPSInst_OPCODE(ir)) {
1299 				case lwc1_op:
1300 				case swc1_op:
1301 					goto emul;
1302 
1303 				case ldc1_op:
1304 				case sdc1_op:
1305 					if (cpu_has_mips_2_3_4_5_r)
1306 						goto emul;
1307 
1308 					goto bc_sigill;
1309 
1310 				case cop1_op:
1311 					goto emul;
1312 
1313 				case cop1x_op:
1314 					if (cpu_has_mips_4_5_64_r2_r6)
1315 						/* its one of ours */
1316 						goto emul;
1317 
1318 					goto bc_sigill;
1319 
1320 				case spec_op:
1321 					switch (MIPSInst_FUNC(ir)) {
1322 					case movc_op:
1323 						if (cpu_has_mips_4_5_r)
1324 							goto emul;
1325 
1326 						goto bc_sigill;
1327 					}
1328 					break;
1329 
1330 				bc_sigill:
1331 					xcp->cp0_epc = bcpc;
1332 					return SIGILL;
1333 				}
1334 
1335 				/*
1336 				 * Single step the non-cp1
1337 				 * instruction in the dslot
1338 				 */
1339 				sig = mips_dsemul(xcp, ir, bcpc, contpc);
1340 				if (sig < 0)
1341 					break;
1342 				if (sig)
1343 					xcp->cp0_epc = bcpc;
1344 				/* SIGILL forces out of the emulation loop.  */
1345 				return sig ? sig : SIGILL;
1346 			} else if (likely) {	/* branch not taken */
1347 				/*
1348 				 * branch likely nullifies
1349 				 * dslot if not taken
1350 				 */
1351 				xcp->cp0_epc += dec_insn.pc_inc;
1352 				contpc += dec_insn.pc_inc;
1353 				/*
1354 				 * else continue & execute
1355 				 * dslot as normal insn
1356 				 */
1357 			}
1358 			break;
1359 
1360 		default:
1361 			if (!(MIPSInst_RS(ir) & 0x10))
1362 				return SIGILL;
1363 
1364 			/* a real fpu computation instruction */
1365 			sig = fpu_emu(xcp, ctx, ir);
1366 			if (sig)
1367 				return sig;
1368 		}
1369 		break;
1370 
1371 	case cop1x_op:
1372 		if (!cpu_has_mips_4_5_64_r2_r6)
1373 			return SIGILL;
1374 
1375 		sig = fpux_emu(xcp, ctx, ir, fault_addr);
1376 		if (sig)
1377 			return sig;
1378 		break;
1379 
1380 	case spec_op:
1381 		if (!cpu_has_mips_4_5_r)
1382 			return SIGILL;
1383 
1384 		if (MIPSInst_FUNC(ir) != movc_op)
1385 			return SIGILL;
1386 		cond = fpucondbit[MIPSInst_RT(ir) >> 2];
1387 		if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
1388 			xcp->regs[MIPSInst_RD(ir)] =
1389 				xcp->regs[MIPSInst_RS(ir)];
1390 		break;
1391 	default:
1392 		return SIGILL;
1393 	}
1394 
1395 	/* we did it !! */
1396 	xcp->cp0_epc = contpc;
1397 	clear_delay_slot(xcp);
1398 
1399 	return 0;
1400 }
1401 
1402 /*
1403  * Conversion table from MIPS compare ops 48-63
1404  * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
1405  */
1406 static const unsigned char cmptab[8] = {
1407 	0,			/* cmp_0 (sig) cmp_sf */
1408 	IEEE754_CUN,		/* cmp_un (sig) cmp_ngle */
1409 	IEEE754_CEQ,		/* cmp_eq (sig) cmp_seq */
1410 	IEEE754_CEQ | IEEE754_CUN,	/* cmp_ueq (sig) cmp_ngl  */
1411 	IEEE754_CLT,		/* cmp_olt (sig) cmp_lt */
1412 	IEEE754_CLT | IEEE754_CUN,	/* cmp_ult (sig) cmp_nge */
1413 	IEEE754_CLT | IEEE754_CEQ,	/* cmp_ole (sig) cmp_le */
1414 	IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN,	/* cmp_ule (sig) cmp_ngt */
1415 };
1416 
1417 static const unsigned char negative_cmptab[8] = {
1418 	0, /* Reserved */
1419 	IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ,
1420 	IEEE754_CLT | IEEE754_CGT | IEEE754_CUN,
1421 	IEEE754_CLT | IEEE754_CGT,
1422 	/* Reserved */
1423 };
1424 
1425 
1426 /*
1427  * Additional MIPS4 instructions
1428  */
1429 
1430 #define DEF3OP(name, p, f1, f2, f3)					\
1431 static union ieee754##p fpemu_##p##_##name(union ieee754##p r,		\
1432 	union ieee754##p s, union ieee754##p t)				\
1433 {									\
1434 	struct _ieee754_csr ieee754_csr_save;				\
1435 	s = f1(s, t);							\
1436 	ieee754_csr_save = ieee754_csr;					\
1437 	s = f2(s, r);							\
1438 	ieee754_csr_save.cx |= ieee754_csr.cx;				\
1439 	ieee754_csr_save.sx |= ieee754_csr.sx;				\
1440 	s = f3(s);							\
1441 	ieee754_csr.cx |= ieee754_csr_save.cx;				\
1442 	ieee754_csr.sx |= ieee754_csr_save.sx;				\
1443 	return s;							\
1444 }
1445 
1446 static union ieee754dp fpemu_dp_recip(union ieee754dp d)
1447 {
1448 	return ieee754dp_div(ieee754dp_one(0), d);
1449 }
1450 
1451 static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
1452 {
1453 	return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
1454 }
1455 
1456 static union ieee754sp fpemu_sp_recip(union ieee754sp s)
1457 {
1458 	return ieee754sp_div(ieee754sp_one(0), s);
1459 }
1460 
1461 static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s)
1462 {
1463 	return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
1464 }
1465 
1466 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
1467 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
1468 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
1469 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
1470 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
1471 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
1472 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
1473 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
1474 
1475 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1476 	mips_instruction ir, void __user **fault_addr)
1477 {
1478 	unsigned int rcsr = 0;	/* resulting csr */
1479 
1480 	MIPS_FPU_EMU_INC_STATS(cp1xops);
1481 
1482 	switch (MIPSInst_FMA_FFMT(ir)) {
1483 	case s_fmt:{		/* 0 */
1484 
1485 		union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
1486 		union ieee754sp fd, fr, fs, ft;
1487 		u32 __user *va;
1488 		u32 val;
1489 
1490 		switch (MIPSInst_FUNC(ir)) {
1491 		case lwxc1_op:
1492 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1493 				xcp->regs[MIPSInst_FT(ir)]);
1494 
1495 			MIPS_FPU_EMU_INC_STATS(loads);
1496 			if (!access_ok(va, sizeof(u32))) {
1497 				MIPS_FPU_EMU_INC_STATS(errors);
1498 				*fault_addr = va;
1499 				return SIGBUS;
1500 			}
1501 			if (__get_user(val, va)) {
1502 				MIPS_FPU_EMU_INC_STATS(errors);
1503 				*fault_addr = va;
1504 				return SIGSEGV;
1505 			}
1506 			SITOREG(val, MIPSInst_FD(ir));
1507 			break;
1508 
1509 		case swxc1_op:
1510 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1511 				xcp->regs[MIPSInst_FT(ir)]);
1512 
1513 			MIPS_FPU_EMU_INC_STATS(stores);
1514 
1515 			SIFROMREG(val, MIPSInst_FS(ir));
1516 			if (!access_ok(va, sizeof(u32))) {
1517 				MIPS_FPU_EMU_INC_STATS(errors);
1518 				*fault_addr = va;
1519 				return SIGBUS;
1520 			}
1521 			if (put_user(val, va)) {
1522 				MIPS_FPU_EMU_INC_STATS(errors);
1523 				*fault_addr = va;
1524 				return SIGSEGV;
1525 			}
1526 			break;
1527 
1528 		case madd_s_op:
1529 			handler = fpemu_sp_madd;
1530 			goto scoptop;
1531 		case msub_s_op:
1532 			handler = fpemu_sp_msub;
1533 			goto scoptop;
1534 		case nmadd_s_op:
1535 			handler = fpemu_sp_nmadd;
1536 			goto scoptop;
1537 		case nmsub_s_op:
1538 			handler = fpemu_sp_nmsub;
1539 			goto scoptop;
1540 
1541 		      scoptop:
1542 			SPFROMREG(fr, MIPSInst_FR(ir));
1543 			SPFROMREG(fs, MIPSInst_FS(ir));
1544 			SPFROMREG(ft, MIPSInst_FT(ir));
1545 			fd = (*handler) (fr, fs, ft);
1546 			SPTOREG(fd, MIPSInst_FD(ir));
1547 
1548 		      copcsr:
1549 			if (ieee754_cxtest(IEEE754_INEXACT)) {
1550 				MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1551 				rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1552 			}
1553 			if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1554 				MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1555 				rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1556 			}
1557 			if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1558 				MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1559 				rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1560 			}
1561 			if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1562 				MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1563 				rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1564 			}
1565 
1566 			ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1567 			if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1568 				/*printk ("SIGFPE: FPU csr = %08x\n",
1569 				   ctx->fcr31); */
1570 				return SIGFPE;
1571 			}
1572 
1573 			break;
1574 
1575 		default:
1576 			return SIGILL;
1577 		}
1578 		break;
1579 	}
1580 
1581 	case d_fmt:{		/* 1 */
1582 		union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
1583 		union ieee754dp fd, fr, fs, ft;
1584 		u64 __user *va;
1585 		u64 val;
1586 
1587 		switch (MIPSInst_FUNC(ir)) {
1588 		case ldxc1_op:
1589 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1590 				xcp->regs[MIPSInst_FT(ir)]);
1591 
1592 			MIPS_FPU_EMU_INC_STATS(loads);
1593 			if (!access_ok(va, sizeof(u64))) {
1594 				MIPS_FPU_EMU_INC_STATS(errors);
1595 				*fault_addr = va;
1596 				return SIGBUS;
1597 			}
1598 			if (__get_user(val, va)) {
1599 				MIPS_FPU_EMU_INC_STATS(errors);
1600 				*fault_addr = va;
1601 				return SIGSEGV;
1602 			}
1603 			DITOREG(val, MIPSInst_FD(ir));
1604 			break;
1605 
1606 		case sdxc1_op:
1607 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1608 				xcp->regs[MIPSInst_FT(ir)]);
1609 
1610 			MIPS_FPU_EMU_INC_STATS(stores);
1611 			DIFROMREG(val, MIPSInst_FS(ir));
1612 			if (!access_ok(va, sizeof(u64))) {
1613 				MIPS_FPU_EMU_INC_STATS(errors);
1614 				*fault_addr = va;
1615 				return SIGBUS;
1616 			}
1617 			if (__put_user(val, va)) {
1618 				MIPS_FPU_EMU_INC_STATS(errors);
1619 				*fault_addr = va;
1620 				return SIGSEGV;
1621 			}
1622 			break;
1623 
1624 		case madd_d_op:
1625 			handler = fpemu_dp_madd;
1626 			goto dcoptop;
1627 		case msub_d_op:
1628 			handler = fpemu_dp_msub;
1629 			goto dcoptop;
1630 		case nmadd_d_op:
1631 			handler = fpemu_dp_nmadd;
1632 			goto dcoptop;
1633 		case nmsub_d_op:
1634 			handler = fpemu_dp_nmsub;
1635 			goto dcoptop;
1636 
1637 		      dcoptop:
1638 			DPFROMREG(fr, MIPSInst_FR(ir));
1639 			DPFROMREG(fs, MIPSInst_FS(ir));
1640 			DPFROMREG(ft, MIPSInst_FT(ir));
1641 			fd = (*handler) (fr, fs, ft);
1642 			DPTOREG(fd, MIPSInst_FD(ir));
1643 			goto copcsr;
1644 
1645 		default:
1646 			return SIGILL;
1647 		}
1648 		break;
1649 	}
1650 
1651 	case 0x3:
1652 		if (MIPSInst_FUNC(ir) != pfetch_op)
1653 			return SIGILL;
1654 
1655 		/* ignore prefx operation */
1656 		break;
1657 
1658 	default:
1659 		return SIGILL;
1660 	}
1661 
1662 	return 0;
1663 }
1664 
1665 
1666 
1667 /*
1668  * Emulate a single COP1 arithmetic instruction.
1669  */
1670 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1671 	mips_instruction ir)
1672 {
1673 	int rfmt;		/* resulting format */
1674 	unsigned int rcsr = 0;	/* resulting csr */
1675 	unsigned int oldrm;
1676 	unsigned int cbit;
1677 	unsigned int cond;
1678 	union {
1679 		union ieee754dp d;
1680 		union ieee754sp s;
1681 		int w;
1682 		s64 l;
1683 	} rv;			/* resulting value */
1684 	u64 bits;
1685 
1686 	MIPS_FPU_EMU_INC_STATS(cp1ops);
1687 	switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
1688 	case s_fmt: {		/* 0 */
1689 		union {
1690 			union ieee754sp(*b) (union ieee754sp, union ieee754sp);
1691 			union ieee754sp(*u) (union ieee754sp);
1692 		} handler;
1693 		union ieee754sp fd, fs, ft;
1694 
1695 		switch (MIPSInst_FUNC(ir)) {
1696 			/* binary ops */
1697 		case fadd_op:
1698 			MIPS_FPU_EMU_INC_STATS(add_s);
1699 			handler.b = ieee754sp_add;
1700 			goto scopbop;
1701 		case fsub_op:
1702 			MIPS_FPU_EMU_INC_STATS(sub_s);
1703 			handler.b = ieee754sp_sub;
1704 			goto scopbop;
1705 		case fmul_op:
1706 			MIPS_FPU_EMU_INC_STATS(mul_s);
1707 			handler.b = ieee754sp_mul;
1708 			goto scopbop;
1709 		case fdiv_op:
1710 			MIPS_FPU_EMU_INC_STATS(div_s);
1711 			handler.b = ieee754sp_div;
1712 			goto scopbop;
1713 
1714 			/* unary  ops */
1715 		case fsqrt_op:
1716 			if (!cpu_has_mips_2_3_4_5_r)
1717 				return SIGILL;
1718 
1719 			MIPS_FPU_EMU_INC_STATS(sqrt_s);
1720 			handler.u = ieee754sp_sqrt;
1721 			goto scopuop;
1722 
1723 		/*
1724 		 * Note that on some MIPS IV implementations such as the
1725 		 * R5000 and R8000 the FSQRT and FRECIP instructions do not
1726 		 * achieve full IEEE-754 accuracy - however this emulator does.
1727 		 */
1728 		case frsqrt_op:
1729 			if (!cpu_has_mips_4_5_64_r2_r6)
1730 				return SIGILL;
1731 
1732 			MIPS_FPU_EMU_INC_STATS(rsqrt_s);
1733 			handler.u = fpemu_sp_rsqrt;
1734 			goto scopuop;
1735 
1736 		case frecip_op:
1737 			if (!cpu_has_mips_4_5_64_r2_r6)
1738 				return SIGILL;
1739 
1740 			MIPS_FPU_EMU_INC_STATS(recip_s);
1741 			handler.u = fpemu_sp_recip;
1742 			goto scopuop;
1743 
1744 		case fmovc_op:
1745 			if (!cpu_has_mips_4_5_r)
1746 				return SIGILL;
1747 
1748 			cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1749 			if (((ctx->fcr31 & cond) != 0) !=
1750 				((MIPSInst_FT(ir) & 1) != 0))
1751 				return 0;
1752 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1753 			break;
1754 
1755 		case fmovz_op:
1756 			if (!cpu_has_mips_4_5_r)
1757 				return SIGILL;
1758 
1759 			if (xcp->regs[MIPSInst_FT(ir)] != 0)
1760 				return 0;
1761 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1762 			break;
1763 
1764 		case fmovn_op:
1765 			if (!cpu_has_mips_4_5_r)
1766 				return SIGILL;
1767 
1768 			if (xcp->regs[MIPSInst_FT(ir)] == 0)
1769 				return 0;
1770 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1771 			break;
1772 
1773 		case fseleqz_op:
1774 			if (!cpu_has_mips_r6)
1775 				return SIGILL;
1776 
1777 			MIPS_FPU_EMU_INC_STATS(seleqz_s);
1778 			SPFROMREG(rv.s, MIPSInst_FT(ir));
1779 			if (rv.w & 0x1)
1780 				rv.w = 0;
1781 			else
1782 				SPFROMREG(rv.s, MIPSInst_FS(ir));
1783 			break;
1784 
1785 		case fselnez_op:
1786 			if (!cpu_has_mips_r6)
1787 				return SIGILL;
1788 
1789 			MIPS_FPU_EMU_INC_STATS(selnez_s);
1790 			SPFROMREG(rv.s, MIPSInst_FT(ir));
1791 			if (rv.w & 0x1)
1792 				SPFROMREG(rv.s, MIPSInst_FS(ir));
1793 			else
1794 				rv.w = 0;
1795 			break;
1796 
1797 		case fmaddf_op: {
1798 			union ieee754sp ft, fs, fd;
1799 
1800 			if (!cpu_has_mips_r6)
1801 				return SIGILL;
1802 
1803 			MIPS_FPU_EMU_INC_STATS(maddf_s);
1804 			SPFROMREG(ft, MIPSInst_FT(ir));
1805 			SPFROMREG(fs, MIPSInst_FS(ir));
1806 			SPFROMREG(fd, MIPSInst_FD(ir));
1807 			rv.s = ieee754sp_maddf(fd, fs, ft);
1808 			goto copcsr;
1809 		}
1810 
1811 		case fmsubf_op: {
1812 			union ieee754sp ft, fs, fd;
1813 
1814 			if (!cpu_has_mips_r6)
1815 				return SIGILL;
1816 
1817 			MIPS_FPU_EMU_INC_STATS(msubf_s);
1818 			SPFROMREG(ft, MIPSInst_FT(ir));
1819 			SPFROMREG(fs, MIPSInst_FS(ir));
1820 			SPFROMREG(fd, MIPSInst_FD(ir));
1821 			rv.s = ieee754sp_msubf(fd, fs, ft);
1822 			goto copcsr;
1823 		}
1824 
1825 		case frint_op: {
1826 			union ieee754sp fs;
1827 
1828 			if (!cpu_has_mips_r6)
1829 				return SIGILL;
1830 
1831 			MIPS_FPU_EMU_INC_STATS(rint_s);
1832 			SPFROMREG(fs, MIPSInst_FS(ir));
1833 			rv.s = ieee754sp_rint(fs);
1834 			goto copcsr;
1835 		}
1836 
1837 		case fclass_op: {
1838 			union ieee754sp fs;
1839 
1840 			if (!cpu_has_mips_r6)
1841 				return SIGILL;
1842 
1843 			MIPS_FPU_EMU_INC_STATS(class_s);
1844 			SPFROMREG(fs, MIPSInst_FS(ir));
1845 			rv.w = ieee754sp_2008class(fs);
1846 			rfmt = w_fmt;
1847 			goto copcsr;
1848 		}
1849 
1850 		case fmin_op: {
1851 			union ieee754sp fs, ft;
1852 
1853 			if (!cpu_has_mips_r6)
1854 				return SIGILL;
1855 
1856 			MIPS_FPU_EMU_INC_STATS(min_s);
1857 			SPFROMREG(ft, MIPSInst_FT(ir));
1858 			SPFROMREG(fs, MIPSInst_FS(ir));
1859 			rv.s = ieee754sp_fmin(fs, ft);
1860 			goto copcsr;
1861 		}
1862 
1863 		case fmina_op: {
1864 			union ieee754sp fs, ft;
1865 
1866 			if (!cpu_has_mips_r6)
1867 				return SIGILL;
1868 
1869 			MIPS_FPU_EMU_INC_STATS(mina_s);
1870 			SPFROMREG(ft, MIPSInst_FT(ir));
1871 			SPFROMREG(fs, MIPSInst_FS(ir));
1872 			rv.s = ieee754sp_fmina(fs, ft);
1873 			goto copcsr;
1874 		}
1875 
1876 		case fmax_op: {
1877 			union ieee754sp fs, ft;
1878 
1879 			if (!cpu_has_mips_r6)
1880 				return SIGILL;
1881 
1882 			MIPS_FPU_EMU_INC_STATS(max_s);
1883 			SPFROMREG(ft, MIPSInst_FT(ir));
1884 			SPFROMREG(fs, MIPSInst_FS(ir));
1885 			rv.s = ieee754sp_fmax(fs, ft);
1886 			goto copcsr;
1887 		}
1888 
1889 		case fmaxa_op: {
1890 			union ieee754sp fs, ft;
1891 
1892 			if (!cpu_has_mips_r6)
1893 				return SIGILL;
1894 
1895 			MIPS_FPU_EMU_INC_STATS(maxa_s);
1896 			SPFROMREG(ft, MIPSInst_FT(ir));
1897 			SPFROMREG(fs, MIPSInst_FS(ir));
1898 			rv.s = ieee754sp_fmaxa(fs, ft);
1899 			goto copcsr;
1900 		}
1901 
1902 		case fabs_op:
1903 			MIPS_FPU_EMU_INC_STATS(abs_s);
1904 			handler.u = ieee754sp_abs;
1905 			goto scopuop;
1906 
1907 		case fneg_op:
1908 			MIPS_FPU_EMU_INC_STATS(neg_s);
1909 			handler.u = ieee754sp_neg;
1910 			goto scopuop;
1911 
1912 		case fmov_op:
1913 			/* an easy one */
1914 			MIPS_FPU_EMU_INC_STATS(mov_s);
1915 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1916 			goto copcsr;
1917 
1918 			/* binary op on handler */
1919 scopbop:
1920 			SPFROMREG(fs, MIPSInst_FS(ir));
1921 			SPFROMREG(ft, MIPSInst_FT(ir));
1922 
1923 			rv.s = (*handler.b) (fs, ft);
1924 			goto copcsr;
1925 scopuop:
1926 			SPFROMREG(fs, MIPSInst_FS(ir));
1927 			rv.s = (*handler.u) (fs);
1928 			goto copcsr;
1929 copcsr:
1930 			if (ieee754_cxtest(IEEE754_INEXACT)) {
1931 				MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1932 				rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1933 			}
1934 			if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1935 				MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1936 				rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1937 			}
1938 			if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1939 				MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1940 				rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1941 			}
1942 			if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) {
1943 				MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv);
1944 				rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
1945 			}
1946 			if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1947 				MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1948 				rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1949 			}
1950 			break;
1951 
1952 			/* unary conv ops */
1953 		case fcvts_op:
1954 			return SIGILL;	/* not defined */
1955 
1956 		case fcvtd_op:
1957 			MIPS_FPU_EMU_INC_STATS(cvt_d_s);
1958 			SPFROMREG(fs, MIPSInst_FS(ir));
1959 			rv.d = ieee754dp_fsp(fs);
1960 			rfmt = d_fmt;
1961 			goto copcsr;
1962 
1963 		case fcvtw_op:
1964 			MIPS_FPU_EMU_INC_STATS(cvt_w_s);
1965 			SPFROMREG(fs, MIPSInst_FS(ir));
1966 			rv.w = ieee754sp_tint(fs);
1967 			rfmt = w_fmt;
1968 			goto copcsr;
1969 
1970 		case fround_op:
1971 		case ftrunc_op:
1972 		case fceil_op:
1973 		case ffloor_op:
1974 			if (!cpu_has_mips_2_3_4_5_r)
1975 				return SIGILL;
1976 
1977 			if (MIPSInst_FUNC(ir) == fceil_op)
1978 				MIPS_FPU_EMU_INC_STATS(ceil_w_s);
1979 			if (MIPSInst_FUNC(ir) == ffloor_op)
1980 				MIPS_FPU_EMU_INC_STATS(floor_w_s);
1981 			if (MIPSInst_FUNC(ir) == fround_op)
1982 				MIPS_FPU_EMU_INC_STATS(round_w_s);
1983 			if (MIPSInst_FUNC(ir) == ftrunc_op)
1984 				MIPS_FPU_EMU_INC_STATS(trunc_w_s);
1985 
1986 			oldrm = ieee754_csr.rm;
1987 			SPFROMREG(fs, MIPSInst_FS(ir));
1988 			ieee754_csr.rm = MIPSInst_FUNC(ir);
1989 			rv.w = ieee754sp_tint(fs);
1990 			ieee754_csr.rm = oldrm;
1991 			rfmt = w_fmt;
1992 			goto copcsr;
1993 
1994 		case fsel_op:
1995 			if (!cpu_has_mips_r6)
1996 				return SIGILL;
1997 
1998 			MIPS_FPU_EMU_INC_STATS(sel_s);
1999 			SPFROMREG(fd, MIPSInst_FD(ir));
2000 			if (fd.bits & 0x1)
2001 				SPFROMREG(rv.s, MIPSInst_FT(ir));
2002 			else
2003 				SPFROMREG(rv.s, MIPSInst_FS(ir));
2004 			break;
2005 
2006 		case fcvtl_op:
2007 			if (!cpu_has_mips_3_4_5_64_r2_r6)
2008 				return SIGILL;
2009 
2010 			MIPS_FPU_EMU_INC_STATS(cvt_l_s);
2011 			SPFROMREG(fs, MIPSInst_FS(ir));
2012 			rv.l = ieee754sp_tlong(fs);
2013 			rfmt = l_fmt;
2014 			goto copcsr;
2015 
2016 		case froundl_op:
2017 		case ftruncl_op:
2018 		case fceill_op:
2019 		case ffloorl_op:
2020 			if (!cpu_has_mips_3_4_5_64_r2_r6)
2021 				return SIGILL;
2022 
2023 			if (MIPSInst_FUNC(ir) == fceill_op)
2024 				MIPS_FPU_EMU_INC_STATS(ceil_l_s);
2025 			if (MIPSInst_FUNC(ir) == ffloorl_op)
2026 				MIPS_FPU_EMU_INC_STATS(floor_l_s);
2027 			if (MIPSInst_FUNC(ir) == froundl_op)
2028 				MIPS_FPU_EMU_INC_STATS(round_l_s);
2029 			if (MIPSInst_FUNC(ir) == ftruncl_op)
2030 				MIPS_FPU_EMU_INC_STATS(trunc_l_s);
2031 
2032 			oldrm = ieee754_csr.rm;
2033 			SPFROMREG(fs, MIPSInst_FS(ir));
2034 			ieee754_csr.rm = MIPSInst_FUNC(ir);
2035 			rv.l = ieee754sp_tlong(fs);
2036 			ieee754_csr.rm = oldrm;
2037 			rfmt = l_fmt;
2038 			goto copcsr;
2039 
2040 		default:
2041 			if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2042 				unsigned int cmpop;
2043 				union ieee754sp fs, ft;
2044 
2045 				cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2046 				SPFROMREG(fs, MIPSInst_FS(ir));
2047 				SPFROMREG(ft, MIPSInst_FT(ir));
2048 				rv.w = ieee754sp_cmp(fs, ft,
2049 					cmptab[cmpop & 0x7], cmpop & 0x8);
2050 				rfmt = -1;
2051 				if ((cmpop & 0x8) && ieee754_cxtest
2052 					(IEEE754_INVALID_OPERATION))
2053 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2054 				else
2055 					goto copcsr;
2056 
2057 			} else
2058 				return SIGILL;
2059 			break;
2060 		}
2061 		break;
2062 	}
2063 
2064 	case d_fmt: {
2065 		union ieee754dp fd, fs, ft;
2066 		union {
2067 			union ieee754dp(*b) (union ieee754dp, union ieee754dp);
2068 			union ieee754dp(*u) (union ieee754dp);
2069 		} handler;
2070 
2071 		switch (MIPSInst_FUNC(ir)) {
2072 			/* binary ops */
2073 		case fadd_op:
2074 			MIPS_FPU_EMU_INC_STATS(add_d);
2075 			handler.b = ieee754dp_add;
2076 			goto dcopbop;
2077 		case fsub_op:
2078 			MIPS_FPU_EMU_INC_STATS(sub_d);
2079 			handler.b = ieee754dp_sub;
2080 			goto dcopbop;
2081 		case fmul_op:
2082 			MIPS_FPU_EMU_INC_STATS(mul_d);
2083 			handler.b = ieee754dp_mul;
2084 			goto dcopbop;
2085 		case fdiv_op:
2086 			MIPS_FPU_EMU_INC_STATS(div_d);
2087 			handler.b = ieee754dp_div;
2088 			goto dcopbop;
2089 
2090 			/* unary  ops */
2091 		case fsqrt_op:
2092 			if (!cpu_has_mips_2_3_4_5_r)
2093 				return SIGILL;
2094 
2095 			MIPS_FPU_EMU_INC_STATS(sqrt_d);
2096 			handler.u = ieee754dp_sqrt;
2097 			goto dcopuop;
2098 		/*
2099 		 * Note that on some MIPS IV implementations such as the
2100 		 * R5000 and R8000 the FSQRT and FRECIP instructions do not
2101 		 * achieve full IEEE-754 accuracy - however this emulator does.
2102 		 */
2103 		case frsqrt_op:
2104 			if (!cpu_has_mips_4_5_64_r2_r6)
2105 				return SIGILL;
2106 
2107 			MIPS_FPU_EMU_INC_STATS(rsqrt_d);
2108 			handler.u = fpemu_dp_rsqrt;
2109 			goto dcopuop;
2110 		case frecip_op:
2111 			if (!cpu_has_mips_4_5_64_r2_r6)
2112 				return SIGILL;
2113 
2114 			MIPS_FPU_EMU_INC_STATS(recip_d);
2115 			handler.u = fpemu_dp_recip;
2116 			goto dcopuop;
2117 		case fmovc_op:
2118 			if (!cpu_has_mips_4_5_r)
2119 				return SIGILL;
2120 
2121 			cond = fpucondbit[MIPSInst_FT(ir) >> 2];
2122 			if (((ctx->fcr31 & cond) != 0) !=
2123 				((MIPSInst_FT(ir) & 1) != 0))
2124 				return 0;
2125 			DPFROMREG(rv.d, MIPSInst_FS(ir));
2126 			break;
2127 		case fmovz_op:
2128 			if (!cpu_has_mips_4_5_r)
2129 				return SIGILL;
2130 
2131 			if (xcp->regs[MIPSInst_FT(ir)] != 0)
2132 				return 0;
2133 			DPFROMREG(rv.d, MIPSInst_FS(ir));
2134 			break;
2135 		case fmovn_op:
2136 			if (!cpu_has_mips_4_5_r)
2137 				return SIGILL;
2138 
2139 			if (xcp->regs[MIPSInst_FT(ir)] == 0)
2140 				return 0;
2141 			DPFROMREG(rv.d, MIPSInst_FS(ir));
2142 			break;
2143 
2144 		case fseleqz_op:
2145 			if (!cpu_has_mips_r6)
2146 				return SIGILL;
2147 
2148 			MIPS_FPU_EMU_INC_STATS(seleqz_d);
2149 			DPFROMREG(rv.d, MIPSInst_FT(ir));
2150 			if (rv.l & 0x1)
2151 				rv.l = 0;
2152 			else
2153 				DPFROMREG(rv.d, MIPSInst_FS(ir));
2154 			break;
2155 
2156 		case fselnez_op:
2157 			if (!cpu_has_mips_r6)
2158 				return SIGILL;
2159 
2160 			MIPS_FPU_EMU_INC_STATS(selnez_d);
2161 			DPFROMREG(rv.d, MIPSInst_FT(ir));
2162 			if (rv.l & 0x1)
2163 				DPFROMREG(rv.d, MIPSInst_FS(ir));
2164 			else
2165 				rv.l = 0;
2166 			break;
2167 
2168 		case fmaddf_op: {
2169 			union ieee754dp ft, fs, fd;
2170 
2171 			if (!cpu_has_mips_r6)
2172 				return SIGILL;
2173 
2174 			MIPS_FPU_EMU_INC_STATS(maddf_d);
2175 			DPFROMREG(ft, MIPSInst_FT(ir));
2176 			DPFROMREG(fs, MIPSInst_FS(ir));
2177 			DPFROMREG(fd, MIPSInst_FD(ir));
2178 			rv.d = ieee754dp_maddf(fd, fs, ft);
2179 			goto copcsr;
2180 		}
2181 
2182 		case fmsubf_op: {
2183 			union ieee754dp ft, fs, fd;
2184 
2185 			if (!cpu_has_mips_r6)
2186 				return SIGILL;
2187 
2188 			MIPS_FPU_EMU_INC_STATS(msubf_d);
2189 			DPFROMREG(ft, MIPSInst_FT(ir));
2190 			DPFROMREG(fs, MIPSInst_FS(ir));
2191 			DPFROMREG(fd, MIPSInst_FD(ir));
2192 			rv.d = ieee754dp_msubf(fd, fs, ft);
2193 			goto copcsr;
2194 		}
2195 
2196 		case frint_op: {
2197 			union ieee754dp fs;
2198 
2199 			if (!cpu_has_mips_r6)
2200 				return SIGILL;
2201 
2202 			MIPS_FPU_EMU_INC_STATS(rint_d);
2203 			DPFROMREG(fs, MIPSInst_FS(ir));
2204 			rv.d = ieee754dp_rint(fs);
2205 			goto copcsr;
2206 		}
2207 
2208 		case fclass_op: {
2209 			union ieee754dp fs;
2210 
2211 			if (!cpu_has_mips_r6)
2212 				return SIGILL;
2213 
2214 			MIPS_FPU_EMU_INC_STATS(class_d);
2215 			DPFROMREG(fs, MIPSInst_FS(ir));
2216 			rv.l = ieee754dp_2008class(fs);
2217 			rfmt = l_fmt;
2218 			goto copcsr;
2219 		}
2220 
2221 		case fmin_op: {
2222 			union ieee754dp fs, ft;
2223 
2224 			if (!cpu_has_mips_r6)
2225 				return SIGILL;
2226 
2227 			MIPS_FPU_EMU_INC_STATS(min_d);
2228 			DPFROMREG(ft, MIPSInst_FT(ir));
2229 			DPFROMREG(fs, MIPSInst_FS(ir));
2230 			rv.d = ieee754dp_fmin(fs, ft);
2231 			goto copcsr;
2232 		}
2233 
2234 		case fmina_op: {
2235 			union ieee754dp fs, ft;
2236 
2237 			if (!cpu_has_mips_r6)
2238 				return SIGILL;
2239 
2240 			MIPS_FPU_EMU_INC_STATS(mina_d);
2241 			DPFROMREG(ft, MIPSInst_FT(ir));
2242 			DPFROMREG(fs, MIPSInst_FS(ir));
2243 			rv.d = ieee754dp_fmina(fs, ft);
2244 			goto copcsr;
2245 		}
2246 
2247 		case fmax_op: {
2248 			union ieee754dp fs, ft;
2249 
2250 			if (!cpu_has_mips_r6)
2251 				return SIGILL;
2252 
2253 			MIPS_FPU_EMU_INC_STATS(max_d);
2254 			DPFROMREG(ft, MIPSInst_FT(ir));
2255 			DPFROMREG(fs, MIPSInst_FS(ir));
2256 			rv.d = ieee754dp_fmax(fs, ft);
2257 			goto copcsr;
2258 		}
2259 
2260 		case fmaxa_op: {
2261 			union ieee754dp fs, ft;
2262 
2263 			if (!cpu_has_mips_r6)
2264 				return SIGILL;
2265 
2266 			MIPS_FPU_EMU_INC_STATS(maxa_d);
2267 			DPFROMREG(ft, MIPSInst_FT(ir));
2268 			DPFROMREG(fs, MIPSInst_FS(ir));
2269 			rv.d = ieee754dp_fmaxa(fs, ft);
2270 			goto copcsr;
2271 		}
2272 
2273 		case fabs_op:
2274 			MIPS_FPU_EMU_INC_STATS(abs_d);
2275 			handler.u = ieee754dp_abs;
2276 			goto dcopuop;
2277 
2278 		case fneg_op:
2279 			MIPS_FPU_EMU_INC_STATS(neg_d);
2280 			handler.u = ieee754dp_neg;
2281 			goto dcopuop;
2282 
2283 		case fmov_op:
2284 			/* an easy one */
2285 			MIPS_FPU_EMU_INC_STATS(mov_d);
2286 			DPFROMREG(rv.d, MIPSInst_FS(ir));
2287 			goto copcsr;
2288 
2289 			/* binary op on handler */
2290 dcopbop:
2291 			DPFROMREG(fs, MIPSInst_FS(ir));
2292 			DPFROMREG(ft, MIPSInst_FT(ir));
2293 
2294 			rv.d = (*handler.b) (fs, ft);
2295 			goto copcsr;
2296 dcopuop:
2297 			DPFROMREG(fs, MIPSInst_FS(ir));
2298 			rv.d = (*handler.u) (fs);
2299 			goto copcsr;
2300 
2301 		/*
2302 		 * unary conv ops
2303 		 */
2304 		case fcvts_op:
2305 			MIPS_FPU_EMU_INC_STATS(cvt_s_d);
2306 			DPFROMREG(fs, MIPSInst_FS(ir));
2307 			rv.s = ieee754sp_fdp(fs);
2308 			rfmt = s_fmt;
2309 			goto copcsr;
2310 
2311 		case fcvtd_op:
2312 			return SIGILL;	/* not defined */
2313 
2314 		case fcvtw_op:
2315 			MIPS_FPU_EMU_INC_STATS(cvt_w_d);
2316 			DPFROMREG(fs, MIPSInst_FS(ir));
2317 			rv.w = ieee754dp_tint(fs);	/* wrong */
2318 			rfmt = w_fmt;
2319 			goto copcsr;
2320 
2321 		case fround_op:
2322 		case ftrunc_op:
2323 		case fceil_op:
2324 		case ffloor_op:
2325 			if (!cpu_has_mips_2_3_4_5_r)
2326 				return SIGILL;
2327 
2328 			if (MIPSInst_FUNC(ir) == fceil_op)
2329 				MIPS_FPU_EMU_INC_STATS(ceil_w_d);
2330 			if (MIPSInst_FUNC(ir) == ffloor_op)
2331 				MIPS_FPU_EMU_INC_STATS(floor_w_d);
2332 			if (MIPSInst_FUNC(ir) == fround_op)
2333 				MIPS_FPU_EMU_INC_STATS(round_w_d);
2334 			if (MIPSInst_FUNC(ir) == ftrunc_op)
2335 				MIPS_FPU_EMU_INC_STATS(trunc_w_d);
2336 
2337 			oldrm = ieee754_csr.rm;
2338 			DPFROMREG(fs, MIPSInst_FS(ir));
2339 			ieee754_csr.rm = MIPSInst_FUNC(ir);
2340 			rv.w = ieee754dp_tint(fs);
2341 			ieee754_csr.rm = oldrm;
2342 			rfmt = w_fmt;
2343 			goto copcsr;
2344 
2345 		case fsel_op:
2346 			if (!cpu_has_mips_r6)
2347 				return SIGILL;
2348 
2349 			MIPS_FPU_EMU_INC_STATS(sel_d);
2350 			DPFROMREG(fd, MIPSInst_FD(ir));
2351 			if (fd.bits & 0x1)
2352 				DPFROMREG(rv.d, MIPSInst_FT(ir));
2353 			else
2354 				DPFROMREG(rv.d, MIPSInst_FS(ir));
2355 			break;
2356 
2357 		case fcvtl_op:
2358 			if (!cpu_has_mips_3_4_5_64_r2_r6)
2359 				return SIGILL;
2360 
2361 			MIPS_FPU_EMU_INC_STATS(cvt_l_d);
2362 			DPFROMREG(fs, MIPSInst_FS(ir));
2363 			rv.l = ieee754dp_tlong(fs);
2364 			rfmt = l_fmt;
2365 			goto copcsr;
2366 
2367 		case froundl_op:
2368 		case ftruncl_op:
2369 		case fceill_op:
2370 		case ffloorl_op:
2371 			if (!cpu_has_mips_3_4_5_64_r2_r6)
2372 				return SIGILL;
2373 
2374 			if (MIPSInst_FUNC(ir) == fceill_op)
2375 				MIPS_FPU_EMU_INC_STATS(ceil_l_d);
2376 			if (MIPSInst_FUNC(ir) == ffloorl_op)
2377 				MIPS_FPU_EMU_INC_STATS(floor_l_d);
2378 			if (MIPSInst_FUNC(ir) == froundl_op)
2379 				MIPS_FPU_EMU_INC_STATS(round_l_d);
2380 			if (MIPSInst_FUNC(ir) == ftruncl_op)
2381 				MIPS_FPU_EMU_INC_STATS(trunc_l_d);
2382 
2383 			oldrm = ieee754_csr.rm;
2384 			DPFROMREG(fs, MIPSInst_FS(ir));
2385 			ieee754_csr.rm = MIPSInst_FUNC(ir);
2386 			rv.l = ieee754dp_tlong(fs);
2387 			ieee754_csr.rm = oldrm;
2388 			rfmt = l_fmt;
2389 			goto copcsr;
2390 
2391 		default:
2392 			if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2393 				unsigned int cmpop;
2394 				union ieee754dp fs, ft;
2395 
2396 				cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2397 				DPFROMREG(fs, MIPSInst_FS(ir));
2398 				DPFROMREG(ft, MIPSInst_FT(ir));
2399 				rv.w = ieee754dp_cmp(fs, ft,
2400 					cmptab[cmpop & 0x7], cmpop & 0x8);
2401 				rfmt = -1;
2402 				if ((cmpop & 0x8)
2403 					&&
2404 					ieee754_cxtest
2405 					(IEEE754_INVALID_OPERATION))
2406 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2407 				else
2408 					goto copcsr;
2409 
2410 			}
2411 			else {
2412 				return SIGILL;
2413 			}
2414 			break;
2415 		}
2416 		break;
2417 	}
2418 
2419 	case w_fmt: {
2420 		union ieee754dp fs;
2421 
2422 		switch (MIPSInst_FUNC(ir)) {
2423 		case fcvts_op:
2424 			/* convert word to single precision real */
2425 			MIPS_FPU_EMU_INC_STATS(cvt_s_w);
2426 			SPFROMREG(fs, MIPSInst_FS(ir));
2427 			rv.s = ieee754sp_fint(fs.bits);
2428 			rfmt = s_fmt;
2429 			goto copcsr;
2430 		case fcvtd_op:
2431 			/* convert word to double precision real */
2432 			MIPS_FPU_EMU_INC_STATS(cvt_d_w);
2433 			SPFROMREG(fs, MIPSInst_FS(ir));
2434 			rv.d = ieee754dp_fint(fs.bits);
2435 			rfmt = d_fmt;
2436 			goto copcsr;
2437 		default: {
2438 			/* Emulating the new CMP.condn.fmt R6 instruction */
2439 #define CMPOP_MASK	0x7
2440 #define SIGN_BIT	(0x1 << 3)
2441 #define PREDICATE_BIT	(0x1 << 4)
2442 
2443 			int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2444 			int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2445 			union ieee754sp fs, ft;
2446 
2447 			/* This is an R6 only instruction */
2448 			if (!cpu_has_mips_r6 ||
2449 			    (MIPSInst_FUNC(ir) & 0x20))
2450 				return SIGILL;
2451 
2452 			if (!sig) {
2453 				if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2454 					switch (cmpop) {
2455 					case 0:
2456 					MIPS_FPU_EMU_INC_STATS(cmp_af_s);
2457 					break;
2458 					case 1:
2459 					MIPS_FPU_EMU_INC_STATS(cmp_un_s);
2460 					break;
2461 					case 2:
2462 					MIPS_FPU_EMU_INC_STATS(cmp_eq_s);
2463 					break;
2464 					case 3:
2465 					MIPS_FPU_EMU_INC_STATS(cmp_ueq_s);
2466 					break;
2467 					case 4:
2468 					MIPS_FPU_EMU_INC_STATS(cmp_lt_s);
2469 					break;
2470 					case 5:
2471 					MIPS_FPU_EMU_INC_STATS(cmp_ult_s);
2472 					break;
2473 					case 6:
2474 					MIPS_FPU_EMU_INC_STATS(cmp_le_s);
2475 					break;
2476 					case 7:
2477 					MIPS_FPU_EMU_INC_STATS(cmp_ule_s);
2478 					break;
2479 					}
2480 				} else {
2481 					switch (cmpop) {
2482 					case 1:
2483 					MIPS_FPU_EMU_INC_STATS(cmp_or_s);
2484 					break;
2485 					case 2:
2486 					MIPS_FPU_EMU_INC_STATS(cmp_une_s);
2487 					break;
2488 					case 3:
2489 					MIPS_FPU_EMU_INC_STATS(cmp_ne_s);
2490 					break;
2491 					}
2492 				}
2493 			} else {
2494 				if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2495 					switch (cmpop) {
2496 					case 0:
2497 					MIPS_FPU_EMU_INC_STATS(cmp_saf_s);
2498 					break;
2499 					case 1:
2500 					MIPS_FPU_EMU_INC_STATS(cmp_sun_s);
2501 					break;
2502 					case 2:
2503 					MIPS_FPU_EMU_INC_STATS(cmp_seq_s);
2504 					break;
2505 					case 3:
2506 					MIPS_FPU_EMU_INC_STATS(cmp_sueq_s);
2507 					break;
2508 					case 4:
2509 					MIPS_FPU_EMU_INC_STATS(cmp_slt_s);
2510 					break;
2511 					case 5:
2512 					MIPS_FPU_EMU_INC_STATS(cmp_sult_s);
2513 					break;
2514 					case 6:
2515 					MIPS_FPU_EMU_INC_STATS(cmp_sle_s);
2516 					break;
2517 					case 7:
2518 					MIPS_FPU_EMU_INC_STATS(cmp_sule_s);
2519 					break;
2520 					}
2521 				} else {
2522 					switch (cmpop) {
2523 					case 1:
2524 					MIPS_FPU_EMU_INC_STATS(cmp_sor_s);
2525 					break;
2526 					case 2:
2527 					MIPS_FPU_EMU_INC_STATS(cmp_sune_s);
2528 					break;
2529 					case 3:
2530 					MIPS_FPU_EMU_INC_STATS(cmp_sne_s);
2531 					break;
2532 					}
2533 				}
2534 			}
2535 
2536 			/* fmt is w_fmt for single precision so fix it */
2537 			rfmt = s_fmt;
2538 			/* default to false */
2539 			rv.w = 0;
2540 
2541 			/* CMP.condn.S */
2542 			SPFROMREG(fs, MIPSInst_FS(ir));
2543 			SPFROMREG(ft, MIPSInst_FT(ir));
2544 
2545 			/* positive predicates */
2546 			if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2547 				if (ieee754sp_cmp(fs, ft, cmptab[cmpop],
2548 						  sig))
2549 				    rv.w = -1; /* true, all 1s */
2550 				if ((sig) &&
2551 				    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2552 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2553 				else
2554 					goto copcsr;
2555 			} else {
2556 				/* negative predicates */
2557 				switch (cmpop) {
2558 				case 1:
2559 				case 2:
2560 				case 3:
2561 					if (ieee754sp_cmp(fs, ft,
2562 							  negative_cmptab[cmpop],
2563 							  sig))
2564 						rv.w = -1; /* true, all 1s */
2565 					if (sig &&
2566 					    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2567 						rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2568 					else
2569 						goto copcsr;
2570 					break;
2571 				default:
2572 					/* Reserved R6 ops */
2573 					return SIGILL;
2574 				}
2575 			}
2576 			break;
2577 			}
2578 		}
2579 		break;
2580 	}
2581 
2582 	case l_fmt:
2583 
2584 		if (!cpu_has_mips_3_4_5_64_r2_r6)
2585 			return SIGILL;
2586 
2587 		DIFROMREG(bits, MIPSInst_FS(ir));
2588 
2589 		switch (MIPSInst_FUNC(ir)) {
2590 		case fcvts_op:
2591 			/* convert long to single precision real */
2592 			MIPS_FPU_EMU_INC_STATS(cvt_s_l);
2593 			rv.s = ieee754sp_flong(bits);
2594 			rfmt = s_fmt;
2595 			goto copcsr;
2596 		case fcvtd_op:
2597 			/* convert long to double precision real */
2598 			MIPS_FPU_EMU_INC_STATS(cvt_d_l);
2599 			rv.d = ieee754dp_flong(bits);
2600 			rfmt = d_fmt;
2601 			goto copcsr;
2602 		default: {
2603 			/* Emulating the new CMP.condn.fmt R6 instruction */
2604 			int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2605 			int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2606 			union ieee754dp fs, ft;
2607 
2608 			if (!cpu_has_mips_r6 ||
2609 			    (MIPSInst_FUNC(ir) & 0x20))
2610 				return SIGILL;
2611 
2612 			if (!sig) {
2613 				if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2614 					switch (cmpop) {
2615 					case 0:
2616 					MIPS_FPU_EMU_INC_STATS(cmp_af_d);
2617 					break;
2618 					case 1:
2619 					MIPS_FPU_EMU_INC_STATS(cmp_un_d);
2620 					break;
2621 					case 2:
2622 					MIPS_FPU_EMU_INC_STATS(cmp_eq_d);
2623 					break;
2624 					case 3:
2625 					MIPS_FPU_EMU_INC_STATS(cmp_ueq_d);
2626 					break;
2627 					case 4:
2628 					MIPS_FPU_EMU_INC_STATS(cmp_lt_d);
2629 					break;
2630 					case 5:
2631 					MIPS_FPU_EMU_INC_STATS(cmp_ult_d);
2632 					break;
2633 					case 6:
2634 					MIPS_FPU_EMU_INC_STATS(cmp_le_d);
2635 					break;
2636 					case 7:
2637 					MIPS_FPU_EMU_INC_STATS(cmp_ule_d);
2638 					break;
2639 					}
2640 				} else {
2641 					switch (cmpop) {
2642 					case 1:
2643 					MIPS_FPU_EMU_INC_STATS(cmp_or_d);
2644 					break;
2645 					case 2:
2646 					MIPS_FPU_EMU_INC_STATS(cmp_une_d);
2647 					break;
2648 					case 3:
2649 					MIPS_FPU_EMU_INC_STATS(cmp_ne_d);
2650 					break;
2651 					}
2652 				}
2653 			} else {
2654 				if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2655 					switch (cmpop) {
2656 					case 0:
2657 					MIPS_FPU_EMU_INC_STATS(cmp_saf_d);
2658 					break;
2659 					case 1:
2660 					MIPS_FPU_EMU_INC_STATS(cmp_sun_d);
2661 					break;
2662 					case 2:
2663 					MIPS_FPU_EMU_INC_STATS(cmp_seq_d);
2664 					break;
2665 					case 3:
2666 					MIPS_FPU_EMU_INC_STATS(cmp_sueq_d);
2667 					break;
2668 					case 4:
2669 					MIPS_FPU_EMU_INC_STATS(cmp_slt_d);
2670 					break;
2671 					case 5:
2672 					MIPS_FPU_EMU_INC_STATS(cmp_sult_d);
2673 					break;
2674 					case 6:
2675 					MIPS_FPU_EMU_INC_STATS(cmp_sle_d);
2676 					break;
2677 					case 7:
2678 					MIPS_FPU_EMU_INC_STATS(cmp_sule_d);
2679 					break;
2680 					}
2681 				} else {
2682 					switch (cmpop) {
2683 					case 1:
2684 					MIPS_FPU_EMU_INC_STATS(cmp_sor_d);
2685 					break;
2686 					case 2:
2687 					MIPS_FPU_EMU_INC_STATS(cmp_sune_d);
2688 					break;
2689 					case 3:
2690 					MIPS_FPU_EMU_INC_STATS(cmp_sne_d);
2691 					break;
2692 					}
2693 				}
2694 			}
2695 
2696 			/* fmt is l_fmt for double precision so fix it */
2697 			rfmt = d_fmt;
2698 			/* default to false */
2699 			rv.l = 0;
2700 
2701 			/* CMP.condn.D */
2702 			DPFROMREG(fs, MIPSInst_FS(ir));
2703 			DPFROMREG(ft, MIPSInst_FT(ir));
2704 
2705 			/* positive predicates */
2706 			if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2707 				if (ieee754dp_cmp(fs, ft,
2708 						  cmptab[cmpop], sig))
2709 				    rv.l = -1LL; /* true, all 1s */
2710 				if (sig &&
2711 				    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2712 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2713 				else
2714 					goto copcsr;
2715 			} else {
2716 				/* negative predicates */
2717 				switch (cmpop) {
2718 				case 1:
2719 				case 2:
2720 				case 3:
2721 					if (ieee754dp_cmp(fs, ft,
2722 							  negative_cmptab[cmpop],
2723 							  sig))
2724 						rv.l = -1LL; /* true, all 1s */
2725 					if (sig &&
2726 					    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2727 						rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2728 					else
2729 						goto copcsr;
2730 					break;
2731 				default:
2732 					/* Reserved R6 ops */
2733 					return SIGILL;
2734 				}
2735 			}
2736 			break;
2737 			}
2738 		}
2739 		break;
2740 
2741 	default:
2742 		return SIGILL;
2743 	}
2744 
2745 	/*
2746 	 * Update the fpu CSR register for this operation.
2747 	 * If an exception is required, generate a tidy SIGFPE exception,
2748 	 * without updating the result register.
2749 	 * Note: cause exception bits do not accumulate, they are rewritten
2750 	 * for each op; only the flag/sticky bits accumulate.
2751 	 */
2752 	ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
2753 	if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
2754 		/*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */
2755 		return SIGFPE;
2756 	}
2757 
2758 	/*
2759 	 * Now we can safely write the result back to the register file.
2760 	 */
2761 	switch (rfmt) {
2762 	case -1:
2763 
2764 		if (cpu_has_mips_4_5_r)
2765 			cbit = fpucondbit[MIPSInst_FD(ir) >> 2];
2766 		else
2767 			cbit = FPU_CSR_COND;
2768 		if (rv.w)
2769 			ctx->fcr31 |= cbit;
2770 		else
2771 			ctx->fcr31 &= ~cbit;
2772 		break;
2773 
2774 	case d_fmt:
2775 		DPTOREG(rv.d, MIPSInst_FD(ir));
2776 		break;
2777 	case s_fmt:
2778 		SPTOREG(rv.s, MIPSInst_FD(ir));
2779 		break;
2780 	case w_fmt:
2781 		SITOREG(rv.w, MIPSInst_FD(ir));
2782 		break;
2783 	case l_fmt:
2784 		if (!cpu_has_mips_3_4_5_64_r2_r6)
2785 			return SIGILL;
2786 
2787 		DITOREG(rv.l, MIPSInst_FD(ir));
2788 		break;
2789 	default:
2790 		return SIGILL;
2791 	}
2792 
2793 	return 0;
2794 }
2795 
2796 /*
2797  * Emulate FPU instructions.
2798  *
2799  * If we use FPU hardware, then we have been typically called to handle
2800  * an unimplemented operation, such as where an operand is a NaN or
2801  * denormalized.  In that case exit the emulation loop after a single
2802  * iteration so as to let hardware execute any subsequent instructions.
2803  *
2804  * If we have no FPU hardware or it has been disabled, then continue
2805  * emulating floating-point instructions until one of these conditions
2806  * has occurred:
2807  *
2808  * - a non-FPU instruction has been encountered,
2809  *
2810  * - an attempt to emulate has ended with a signal,
2811  *
2812  * - the ISA mode has been switched.
2813  *
2814  * We need to terminate the emulation loop if we got switched to the
2815  * MIPS16 mode, whether supported or not, so that we do not attempt
2816  * to emulate a MIPS16 instruction as a regular MIPS FPU instruction.
2817  * Similarly if we got switched to the microMIPS mode and only the
2818  * regular MIPS mode is supported, so that we do not attempt to emulate
2819  * a microMIPS instruction as a regular MIPS FPU instruction.  Or if
2820  * we got switched to the regular MIPS mode and only the microMIPS mode
2821  * is supported, so that we do not attempt to emulate a regular MIPS
2822  * instruction that should cause an Address Error exception instead.
2823  * For simplicity we always terminate upon an ISA mode switch.
2824  */
2825 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
2826 	int has_fpu, void __user **fault_addr)
2827 {
2828 	unsigned long oldepc, prevepc;
2829 	struct mm_decoded_insn dec_insn;
2830 	u16 instr[4];
2831 	u16 *instr_ptr;
2832 	int sig = 0;
2833 
2834 	/*
2835 	 * Initialize context if it hasn't been used already, otherwise ensure
2836 	 * it has been saved to struct thread_struct.
2837 	 */
2838 	if (!init_fp_ctx(current))
2839 		lose_fpu(1);
2840 
2841 	oldepc = xcp->cp0_epc;
2842 	do {
2843 		prevepc = xcp->cp0_epc;
2844 
2845 		if (get_isa16_mode(prevepc) && cpu_has_mmips) {
2846 			/*
2847 			 * Get next 2 microMIPS instructions and convert them
2848 			 * into 32-bit instructions.
2849 			 */
2850 			if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
2851 			    (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
2852 			    (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
2853 			    (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
2854 				MIPS_FPU_EMU_INC_STATS(errors);
2855 				return SIGBUS;
2856 			}
2857 			instr_ptr = instr;
2858 
2859 			/* Get first instruction. */
2860 			if (mm_insn_16bit(*instr_ptr)) {
2861 				/* Duplicate the half-word. */
2862 				dec_insn.insn = (*instr_ptr << 16) |
2863 					(*instr_ptr);
2864 				/* 16-bit instruction. */
2865 				dec_insn.pc_inc = 2;
2866 				instr_ptr += 1;
2867 			} else {
2868 				dec_insn.insn = (*instr_ptr << 16) |
2869 					*(instr_ptr+1);
2870 				/* 32-bit instruction. */
2871 				dec_insn.pc_inc = 4;
2872 				instr_ptr += 2;
2873 			}
2874 			/* Get second instruction. */
2875 			if (mm_insn_16bit(*instr_ptr)) {
2876 				/* Duplicate the half-word. */
2877 				dec_insn.next_insn = (*instr_ptr << 16) |
2878 					(*instr_ptr);
2879 				/* 16-bit instruction. */
2880 				dec_insn.next_pc_inc = 2;
2881 			} else {
2882 				dec_insn.next_insn = (*instr_ptr << 16) |
2883 					*(instr_ptr+1);
2884 				/* 32-bit instruction. */
2885 				dec_insn.next_pc_inc = 4;
2886 			}
2887 			dec_insn.micro_mips_mode = 1;
2888 		} else {
2889 			if ((get_user(dec_insn.insn,
2890 			    (mips_instruction __user *) xcp->cp0_epc)) ||
2891 			    (get_user(dec_insn.next_insn,
2892 			    (mips_instruction __user *)(xcp->cp0_epc+4)))) {
2893 				MIPS_FPU_EMU_INC_STATS(errors);
2894 				return SIGBUS;
2895 			}
2896 			dec_insn.pc_inc = 4;
2897 			dec_insn.next_pc_inc = 4;
2898 			dec_insn.micro_mips_mode = 0;
2899 		}
2900 
2901 		if ((dec_insn.insn == 0) ||
2902 		   ((dec_insn.pc_inc == 2) &&
2903 		   ((dec_insn.insn & 0xffff) == MM_NOP16)))
2904 			xcp->cp0_epc += dec_insn.pc_inc;	/* Skip NOPs */
2905 		else {
2906 			/*
2907 			 * The 'ieee754_csr' is an alias of ctx->fcr31.
2908 			 * No need to copy ctx->fcr31 to ieee754_csr.
2909 			 */
2910 			sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
2911 		}
2912 
2913 		if (has_fpu)
2914 			break;
2915 		if (sig)
2916 			break;
2917 		/*
2918 		 * We have to check for the ISA bit explicitly here,
2919 		 * because `get_isa16_mode' may return 0 if support
2920 		 * for code compression has been globally disabled,
2921 		 * or otherwise we may produce the wrong signal or
2922 		 * even proceed successfully where we must not.
2923 		 */
2924 		if ((xcp->cp0_epc ^ prevepc) & 0x1)
2925 			break;
2926 
2927 		cond_resched();
2928 	} while (xcp->cp0_epc > prevepc);
2929 
2930 	/* SIGILL indicates a non-fpu instruction */
2931 	if (sig == SIGILL && xcp->cp0_epc != oldepc)
2932 		/* but if EPC has advanced, then ignore it */
2933 		sig = 0;
2934 
2935 	return sig;
2936 }
2937