xref: /openbmc/linux/arch/mips/math-emu/cp1emu.c (revision 84d517f3)
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  *  59 Temple Place - Suite 330, Boston MA 02111-1307, 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/module.h>
38 #include <linux/debugfs.h>
39 #include <linux/perf_event.h>
40 
41 #include <asm/inst.h>
42 #include <asm/bootinfo.h>
43 #include <asm/processor.h>
44 #include <asm/ptrace.h>
45 #include <asm/signal.h>
46 #include <asm/mipsregs.h>
47 #include <asm/fpu_emulator.h>
48 #include <asm/fpu.h>
49 #include <asm/uaccess.h>
50 #include <asm/branch.h>
51 
52 #include "ieee754.h"
53 
54 /* Strap kernel emulator for full MIPS IV emulation */
55 
56 #ifdef __mips
57 #undef __mips
58 #endif
59 #define __mips 4
60 
61 /* Function which emulates a floating point instruction. */
62 
63 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
64 	mips_instruction);
65 
66 #if __mips >= 4 && __mips != 32
67 static int fpux_emu(struct pt_regs *,
68 	struct mips_fpu_struct *, mips_instruction, void *__user *);
69 #endif
70 
71 /* Further private data for which no space exists in mips_fpu_struct */
72 
73 #ifdef CONFIG_DEBUG_FS
74 DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
75 #endif
76 
77 /* Control registers */
78 
79 #define FPCREG_RID	0	/* $0  = revision id */
80 #define FPCREG_CSR	31	/* $31 = csr */
81 
82 /* Determine rounding mode from the RM bits of the FCSR */
83 #define modeindex(v) ((v) & FPU_CSR_RM)
84 
85 /* microMIPS bitfields */
86 #define MM_POOL32A_MINOR_MASK	0x3f
87 #define MM_POOL32A_MINOR_SHIFT	0x6
88 #define MM_MIPS32_COND_FC	0x30
89 
90 /* Convert Mips rounding mode (0..3) to IEEE library modes. */
91 static const unsigned char ieee_rm[4] = {
92 	[FPU_CSR_RN] = IEEE754_RN,
93 	[FPU_CSR_RZ] = IEEE754_RZ,
94 	[FPU_CSR_RU] = IEEE754_RU,
95 	[FPU_CSR_RD] = IEEE754_RD,
96 };
97 /* Convert IEEE library modes to Mips rounding mode (0..3). */
98 static const unsigned char mips_rm[4] = {
99 	[IEEE754_RN] = FPU_CSR_RN,
100 	[IEEE754_RZ] = FPU_CSR_RZ,
101 	[IEEE754_RD] = FPU_CSR_RD,
102 	[IEEE754_RU] = FPU_CSR_RU,
103 };
104 
105 #if __mips >= 4
106 /* convert condition code register number to csr bit */
107 static const unsigned int fpucondbit[8] = {
108 	FPU_CSR_COND0,
109 	FPU_CSR_COND1,
110 	FPU_CSR_COND2,
111 	FPU_CSR_COND3,
112 	FPU_CSR_COND4,
113 	FPU_CSR_COND5,
114 	FPU_CSR_COND6,
115 	FPU_CSR_COND7
116 };
117 #endif
118 
119 /* (microMIPS) Convert 16-bit register encoding to 32-bit register encoding. */
120 static const unsigned int reg16to32map[8] = {16, 17, 2, 3, 4, 5, 6, 7};
121 
122 /* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
123 static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
124 static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
125 static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
126 static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
127 
128 /*
129  * This functions translates a 32-bit microMIPS instruction
130  * into a 32-bit MIPS32 instruction. Returns 0 on success
131  * and SIGILL otherwise.
132  */
133 static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
134 {
135 	union mips_instruction insn = *insn_ptr;
136 	union mips_instruction mips32_insn = insn;
137 	int func, fmt, op;
138 
139 	switch (insn.mm_i_format.opcode) {
140 	case mm_ldc132_op:
141 		mips32_insn.mm_i_format.opcode = ldc1_op;
142 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
143 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
144 		break;
145 	case mm_lwc132_op:
146 		mips32_insn.mm_i_format.opcode = lwc1_op;
147 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
148 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
149 		break;
150 	case mm_sdc132_op:
151 		mips32_insn.mm_i_format.opcode = sdc1_op;
152 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
153 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
154 		break;
155 	case mm_swc132_op:
156 		mips32_insn.mm_i_format.opcode = swc1_op;
157 		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
158 		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
159 		break;
160 	case mm_pool32i_op:
161 		/* NOTE: offset is << by 1 if in microMIPS mode. */
162 		if ((insn.mm_i_format.rt == mm_bc1f_op) ||
163 		    (insn.mm_i_format.rt == mm_bc1t_op)) {
164 			mips32_insn.fb_format.opcode = cop1_op;
165 			mips32_insn.fb_format.bc = bc_op;
166 			mips32_insn.fb_format.flag =
167 				(insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
168 		} else
169 			return SIGILL;
170 		break;
171 	case mm_pool32f_op:
172 		switch (insn.mm_fp0_format.func) {
173 		case mm_32f_01_op:
174 		case mm_32f_11_op:
175 		case mm_32f_02_op:
176 		case mm_32f_12_op:
177 		case mm_32f_41_op:
178 		case mm_32f_51_op:
179 		case mm_32f_42_op:
180 		case mm_32f_52_op:
181 			op = insn.mm_fp0_format.func;
182 			if (op == mm_32f_01_op)
183 				func = madd_s_op;
184 			else if (op == mm_32f_11_op)
185 				func = madd_d_op;
186 			else if (op == mm_32f_02_op)
187 				func = nmadd_s_op;
188 			else if (op == mm_32f_12_op)
189 				func = nmadd_d_op;
190 			else if (op == mm_32f_41_op)
191 				func = msub_s_op;
192 			else if (op == mm_32f_51_op)
193 				func = msub_d_op;
194 			else if (op == mm_32f_42_op)
195 				func = nmsub_s_op;
196 			else
197 				func = nmsub_d_op;
198 			mips32_insn.fp6_format.opcode = cop1x_op;
199 			mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
200 			mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
201 			mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
202 			mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
203 			mips32_insn.fp6_format.func = func;
204 			break;
205 		case mm_32f_10_op:
206 			func = -1;	/* Invalid */
207 			op = insn.mm_fp5_format.op & 0x7;
208 			if (op == mm_ldxc1_op)
209 				func = ldxc1_op;
210 			else if (op == mm_sdxc1_op)
211 				func = sdxc1_op;
212 			else if (op == mm_lwxc1_op)
213 				func = lwxc1_op;
214 			else if (op == mm_swxc1_op)
215 				func = swxc1_op;
216 
217 			if (func != -1) {
218 				mips32_insn.r_format.opcode = cop1x_op;
219 				mips32_insn.r_format.rs =
220 					insn.mm_fp5_format.base;
221 				mips32_insn.r_format.rt =
222 					insn.mm_fp5_format.index;
223 				mips32_insn.r_format.rd = 0;
224 				mips32_insn.r_format.re = insn.mm_fp5_format.fd;
225 				mips32_insn.r_format.func = func;
226 			} else
227 				return SIGILL;
228 			break;
229 		case mm_32f_40_op:
230 			op = -1;	/* Invalid */
231 			if (insn.mm_fp2_format.op == mm_fmovt_op)
232 				op = 1;
233 			else if (insn.mm_fp2_format.op == mm_fmovf_op)
234 				op = 0;
235 			if (op != -1) {
236 				mips32_insn.fp0_format.opcode = cop1_op;
237 				mips32_insn.fp0_format.fmt =
238 					sdps_format[insn.mm_fp2_format.fmt];
239 				mips32_insn.fp0_format.ft =
240 					(insn.mm_fp2_format.cc<<2) + op;
241 				mips32_insn.fp0_format.fs =
242 					insn.mm_fp2_format.fs;
243 				mips32_insn.fp0_format.fd =
244 					insn.mm_fp2_format.fd;
245 				mips32_insn.fp0_format.func = fmovc_op;
246 			} else
247 				return SIGILL;
248 			break;
249 		case mm_32f_60_op:
250 			func = -1;	/* Invalid */
251 			if (insn.mm_fp0_format.op == mm_fadd_op)
252 				func = fadd_op;
253 			else if (insn.mm_fp0_format.op == mm_fsub_op)
254 				func = fsub_op;
255 			else if (insn.mm_fp0_format.op == mm_fmul_op)
256 				func = fmul_op;
257 			else if (insn.mm_fp0_format.op == mm_fdiv_op)
258 				func = fdiv_op;
259 			if (func != -1) {
260 				mips32_insn.fp0_format.opcode = cop1_op;
261 				mips32_insn.fp0_format.fmt =
262 					sdps_format[insn.mm_fp0_format.fmt];
263 				mips32_insn.fp0_format.ft =
264 					insn.mm_fp0_format.ft;
265 				mips32_insn.fp0_format.fs =
266 					insn.mm_fp0_format.fs;
267 				mips32_insn.fp0_format.fd =
268 					insn.mm_fp0_format.fd;
269 				mips32_insn.fp0_format.func = func;
270 			} else
271 				return SIGILL;
272 			break;
273 		case mm_32f_70_op:
274 			func = -1;	/* Invalid */
275 			if (insn.mm_fp0_format.op == mm_fmovn_op)
276 				func = fmovn_op;
277 			else if (insn.mm_fp0_format.op == mm_fmovz_op)
278 				func = fmovz_op;
279 			if (func != -1) {
280 				mips32_insn.fp0_format.opcode = cop1_op;
281 				mips32_insn.fp0_format.fmt =
282 					sdps_format[insn.mm_fp0_format.fmt];
283 				mips32_insn.fp0_format.ft =
284 					insn.mm_fp0_format.ft;
285 				mips32_insn.fp0_format.fs =
286 					insn.mm_fp0_format.fs;
287 				mips32_insn.fp0_format.fd =
288 					insn.mm_fp0_format.fd;
289 				mips32_insn.fp0_format.func = func;
290 			} else
291 				return SIGILL;
292 			break;
293 		case mm_32f_73_op:    /* POOL32FXF */
294 			switch (insn.mm_fp1_format.op) {
295 			case mm_movf0_op:
296 			case mm_movf1_op:
297 			case mm_movt0_op:
298 			case mm_movt1_op:
299 				if ((insn.mm_fp1_format.op & 0x7f) ==
300 				    mm_movf0_op)
301 					op = 0;
302 				else
303 					op = 1;
304 				mips32_insn.r_format.opcode = spec_op;
305 				mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
306 				mips32_insn.r_format.rt =
307 					(insn.mm_fp4_format.cc << 2) + op;
308 				mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
309 				mips32_insn.r_format.re = 0;
310 				mips32_insn.r_format.func = movc_op;
311 				break;
312 			case mm_fcvtd0_op:
313 			case mm_fcvtd1_op:
314 			case mm_fcvts0_op:
315 			case mm_fcvts1_op:
316 				if ((insn.mm_fp1_format.op & 0x7f) ==
317 				    mm_fcvtd0_op) {
318 					func = fcvtd_op;
319 					fmt = swl_format[insn.mm_fp3_format.fmt];
320 				} else {
321 					func = fcvts_op;
322 					fmt = dwl_format[insn.mm_fp3_format.fmt];
323 				}
324 				mips32_insn.fp0_format.opcode = cop1_op;
325 				mips32_insn.fp0_format.fmt = fmt;
326 				mips32_insn.fp0_format.ft = 0;
327 				mips32_insn.fp0_format.fs =
328 					insn.mm_fp3_format.fs;
329 				mips32_insn.fp0_format.fd =
330 					insn.mm_fp3_format.rt;
331 				mips32_insn.fp0_format.func = func;
332 				break;
333 			case mm_fmov0_op:
334 			case mm_fmov1_op:
335 			case mm_fabs0_op:
336 			case mm_fabs1_op:
337 			case mm_fneg0_op:
338 			case mm_fneg1_op:
339 				if ((insn.mm_fp1_format.op & 0x7f) ==
340 				    mm_fmov0_op)
341 					func = fmov_op;
342 				else if ((insn.mm_fp1_format.op & 0x7f) ==
343 					 mm_fabs0_op)
344 					func = fabs_op;
345 				else
346 					func = fneg_op;
347 				mips32_insn.fp0_format.opcode = cop1_op;
348 				mips32_insn.fp0_format.fmt =
349 					sdps_format[insn.mm_fp3_format.fmt];
350 				mips32_insn.fp0_format.ft = 0;
351 				mips32_insn.fp0_format.fs =
352 					insn.mm_fp3_format.fs;
353 				mips32_insn.fp0_format.fd =
354 					insn.mm_fp3_format.rt;
355 				mips32_insn.fp0_format.func = func;
356 				break;
357 			case mm_ffloorl_op:
358 			case mm_ffloorw_op:
359 			case mm_fceill_op:
360 			case mm_fceilw_op:
361 			case mm_ftruncl_op:
362 			case mm_ftruncw_op:
363 			case mm_froundl_op:
364 			case mm_froundw_op:
365 			case mm_fcvtl_op:
366 			case mm_fcvtw_op:
367 				if (insn.mm_fp1_format.op == mm_ffloorl_op)
368 					func = ffloorl_op;
369 				else if (insn.mm_fp1_format.op == mm_ffloorw_op)
370 					func = ffloor_op;
371 				else if (insn.mm_fp1_format.op == mm_fceill_op)
372 					func = fceill_op;
373 				else if (insn.mm_fp1_format.op == mm_fceilw_op)
374 					func = fceil_op;
375 				else if (insn.mm_fp1_format.op == mm_ftruncl_op)
376 					func = ftruncl_op;
377 				else if (insn.mm_fp1_format.op == mm_ftruncw_op)
378 					func = ftrunc_op;
379 				else if (insn.mm_fp1_format.op == mm_froundl_op)
380 					func = froundl_op;
381 				else if (insn.mm_fp1_format.op == mm_froundw_op)
382 					func = fround_op;
383 				else if (insn.mm_fp1_format.op == mm_fcvtl_op)
384 					func = fcvtl_op;
385 				else
386 					func = fcvtw_op;
387 				mips32_insn.fp0_format.opcode = cop1_op;
388 				mips32_insn.fp0_format.fmt =
389 					sd_format[insn.mm_fp1_format.fmt];
390 				mips32_insn.fp0_format.ft = 0;
391 				mips32_insn.fp0_format.fs =
392 					insn.mm_fp1_format.fs;
393 				mips32_insn.fp0_format.fd =
394 					insn.mm_fp1_format.rt;
395 				mips32_insn.fp0_format.func = func;
396 				break;
397 			case mm_frsqrt_op:
398 			case mm_fsqrt_op:
399 			case mm_frecip_op:
400 				if (insn.mm_fp1_format.op == mm_frsqrt_op)
401 					func = frsqrt_op;
402 				else if (insn.mm_fp1_format.op == mm_fsqrt_op)
403 					func = fsqrt_op;
404 				else
405 					func = frecip_op;
406 				mips32_insn.fp0_format.opcode = cop1_op;
407 				mips32_insn.fp0_format.fmt =
408 					sdps_format[insn.mm_fp1_format.fmt];
409 				mips32_insn.fp0_format.ft = 0;
410 				mips32_insn.fp0_format.fs =
411 					insn.mm_fp1_format.fs;
412 				mips32_insn.fp0_format.fd =
413 					insn.mm_fp1_format.rt;
414 				mips32_insn.fp0_format.func = func;
415 				break;
416 			case mm_mfc1_op:
417 			case mm_mtc1_op:
418 			case mm_cfc1_op:
419 			case mm_ctc1_op:
420 			case mm_mfhc1_op:
421 			case mm_mthc1_op:
422 				if (insn.mm_fp1_format.op == mm_mfc1_op)
423 					op = mfc_op;
424 				else if (insn.mm_fp1_format.op == mm_mtc1_op)
425 					op = mtc_op;
426 				else if (insn.mm_fp1_format.op == mm_cfc1_op)
427 					op = cfc_op;
428 				else if (insn.mm_fp1_format.op == mm_ctc1_op)
429 					op = ctc_op;
430 				else if (insn.mm_fp1_format.op == mm_mfhc1_op)
431 					op = mfhc_op;
432 				else
433 					op = mthc_op;
434 				mips32_insn.fp1_format.opcode = cop1_op;
435 				mips32_insn.fp1_format.op = op;
436 				mips32_insn.fp1_format.rt =
437 					insn.mm_fp1_format.rt;
438 				mips32_insn.fp1_format.fs =
439 					insn.mm_fp1_format.fs;
440 				mips32_insn.fp1_format.fd = 0;
441 				mips32_insn.fp1_format.func = 0;
442 				break;
443 			default:
444 				return SIGILL;
445 			}
446 			break;
447 		case mm_32f_74_op:	/* c.cond.fmt */
448 			mips32_insn.fp0_format.opcode = cop1_op;
449 			mips32_insn.fp0_format.fmt =
450 				sdps_format[insn.mm_fp4_format.fmt];
451 			mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
452 			mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
453 			mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
454 			mips32_insn.fp0_format.func =
455 				insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
456 			break;
457 		default:
458 			return SIGILL;
459 		}
460 		break;
461 	default:
462 		return SIGILL;
463 	}
464 
465 	*insn_ptr = mips32_insn;
466 	return 0;
467 }
468 
469 int mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
470 		     unsigned long *contpc)
471 {
472 	union mips_instruction insn = (union mips_instruction)dec_insn.insn;
473 	int bc_false = 0;
474 	unsigned int fcr31;
475 	unsigned int bit;
476 
477 	if (!cpu_has_mmips)
478 		return 0;
479 
480 	switch (insn.mm_i_format.opcode) {
481 	case mm_pool32a_op:
482 		if ((insn.mm_i_format.simmediate & MM_POOL32A_MINOR_MASK) ==
483 		    mm_pool32axf_op) {
484 			switch (insn.mm_i_format.simmediate >>
485 				MM_POOL32A_MINOR_SHIFT) {
486 			case mm_jalr_op:
487 			case mm_jalrhb_op:
488 			case mm_jalrs_op:
489 			case mm_jalrshb_op:
490 				if (insn.mm_i_format.rt != 0)	/* Not mm_jr */
491 					regs->regs[insn.mm_i_format.rt] =
492 						regs->cp0_epc +
493 						dec_insn.pc_inc +
494 						dec_insn.next_pc_inc;
495 				*contpc = regs->regs[insn.mm_i_format.rs];
496 				return 1;
497 			}
498 		}
499 		break;
500 	case mm_pool32i_op:
501 		switch (insn.mm_i_format.rt) {
502 		case mm_bltzals_op:
503 		case mm_bltzal_op:
504 			regs->regs[31] = regs->cp0_epc +
505 				dec_insn.pc_inc +
506 				dec_insn.next_pc_inc;
507 			/* Fall through */
508 		case mm_bltz_op:
509 			if ((long)regs->regs[insn.mm_i_format.rs] < 0)
510 				*contpc = regs->cp0_epc +
511 					dec_insn.pc_inc +
512 					(insn.mm_i_format.simmediate << 1);
513 			else
514 				*contpc = regs->cp0_epc +
515 					dec_insn.pc_inc +
516 					dec_insn.next_pc_inc;
517 			return 1;
518 		case mm_bgezals_op:
519 		case mm_bgezal_op:
520 			regs->regs[31] = regs->cp0_epc +
521 					dec_insn.pc_inc +
522 					dec_insn.next_pc_inc;
523 			/* Fall through */
524 		case mm_bgez_op:
525 			if ((long)regs->regs[insn.mm_i_format.rs] >= 0)
526 				*contpc = regs->cp0_epc +
527 					dec_insn.pc_inc +
528 					(insn.mm_i_format.simmediate << 1);
529 			else
530 				*contpc = regs->cp0_epc +
531 					dec_insn.pc_inc +
532 					dec_insn.next_pc_inc;
533 			return 1;
534 		case mm_blez_op:
535 			if ((long)regs->regs[insn.mm_i_format.rs] <= 0)
536 				*contpc = regs->cp0_epc +
537 					dec_insn.pc_inc +
538 					(insn.mm_i_format.simmediate << 1);
539 			else
540 				*contpc = regs->cp0_epc +
541 					dec_insn.pc_inc +
542 					dec_insn.next_pc_inc;
543 			return 1;
544 		case mm_bgtz_op:
545 			if ((long)regs->regs[insn.mm_i_format.rs] <= 0)
546 				*contpc = regs->cp0_epc +
547 					dec_insn.pc_inc +
548 					(insn.mm_i_format.simmediate << 1);
549 			else
550 				*contpc = regs->cp0_epc +
551 					dec_insn.pc_inc +
552 					dec_insn.next_pc_inc;
553 			return 1;
554 		case mm_bc2f_op:
555 		case mm_bc1f_op:
556 			bc_false = 1;
557 			/* Fall through */
558 		case mm_bc2t_op:
559 		case mm_bc1t_op:
560 			preempt_disable();
561 			if (is_fpu_owner())
562 				asm volatile("cfc1\t%0,$31" : "=r" (fcr31));
563 			else
564 				fcr31 = current->thread.fpu.fcr31;
565 			preempt_enable();
566 
567 			if (bc_false)
568 				fcr31 = ~fcr31;
569 
570 			bit = (insn.mm_i_format.rs >> 2);
571 			bit += (bit != 0);
572 			bit += 23;
573 			if (fcr31 & (1 << bit))
574 				*contpc = regs->cp0_epc +
575 					dec_insn.pc_inc +
576 					(insn.mm_i_format.simmediate << 1);
577 			else
578 				*contpc = regs->cp0_epc +
579 					dec_insn.pc_inc + dec_insn.next_pc_inc;
580 			return 1;
581 		}
582 		break;
583 	case mm_pool16c_op:
584 		switch (insn.mm_i_format.rt) {
585 		case mm_jalr16_op:
586 		case mm_jalrs16_op:
587 			regs->regs[31] = regs->cp0_epc +
588 				dec_insn.pc_inc + dec_insn.next_pc_inc;
589 			/* Fall through */
590 		case mm_jr16_op:
591 			*contpc = regs->regs[insn.mm_i_format.rs];
592 			return 1;
593 		}
594 		break;
595 	case mm_beqz16_op:
596 		if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] == 0)
597 			*contpc = regs->cp0_epc +
598 				dec_insn.pc_inc +
599 				(insn.mm_b1_format.simmediate << 1);
600 		else
601 			*contpc = regs->cp0_epc +
602 				dec_insn.pc_inc + dec_insn.next_pc_inc;
603 		return 1;
604 	case mm_bnez16_op:
605 		if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] != 0)
606 			*contpc = regs->cp0_epc +
607 				dec_insn.pc_inc +
608 				(insn.mm_b1_format.simmediate << 1);
609 		else
610 			*contpc = regs->cp0_epc +
611 				dec_insn.pc_inc + dec_insn.next_pc_inc;
612 		return 1;
613 	case mm_b16_op:
614 		*contpc = regs->cp0_epc + dec_insn.pc_inc +
615 			 (insn.mm_b0_format.simmediate << 1);
616 		return 1;
617 	case mm_beq32_op:
618 		if (regs->regs[insn.mm_i_format.rs] ==
619 		    regs->regs[insn.mm_i_format.rt])
620 			*contpc = regs->cp0_epc +
621 				dec_insn.pc_inc +
622 				(insn.mm_i_format.simmediate << 1);
623 		else
624 			*contpc = regs->cp0_epc +
625 				dec_insn.pc_inc +
626 				dec_insn.next_pc_inc;
627 		return 1;
628 	case mm_bne32_op:
629 		if (regs->regs[insn.mm_i_format.rs] !=
630 		    regs->regs[insn.mm_i_format.rt])
631 			*contpc = regs->cp0_epc +
632 				dec_insn.pc_inc +
633 				(insn.mm_i_format.simmediate << 1);
634 		else
635 			*contpc = regs->cp0_epc +
636 				dec_insn.pc_inc + dec_insn.next_pc_inc;
637 		return 1;
638 	case mm_jalx32_op:
639 		regs->regs[31] = regs->cp0_epc +
640 			dec_insn.pc_inc + dec_insn.next_pc_inc;
641 		*contpc = regs->cp0_epc + dec_insn.pc_inc;
642 		*contpc >>= 28;
643 		*contpc <<= 28;
644 		*contpc |= (insn.j_format.target << 2);
645 		return 1;
646 	case mm_jals32_op:
647 	case mm_jal32_op:
648 		regs->regs[31] = regs->cp0_epc +
649 			dec_insn.pc_inc + dec_insn.next_pc_inc;
650 		/* Fall through */
651 	case mm_j32_op:
652 		*contpc = regs->cp0_epc + dec_insn.pc_inc;
653 		*contpc >>= 27;
654 		*contpc <<= 27;
655 		*contpc |= (insn.j_format.target << 1);
656 		set_isa16_mode(*contpc);
657 		return 1;
658 	}
659 	return 0;
660 }
661 
662 /*
663  * Redundant with logic already in kernel/branch.c,
664  * embedded in compute_return_epc.  At some point,
665  * a single subroutine should be used across both
666  * modules.
667  */
668 static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
669 			 unsigned long *contpc)
670 {
671 	union mips_instruction insn = (union mips_instruction)dec_insn.insn;
672 	unsigned int fcr31;
673 	unsigned int bit = 0;
674 
675 	switch (insn.i_format.opcode) {
676 	case spec_op:
677 		switch (insn.r_format.func) {
678 		case jalr_op:
679 			regs->regs[insn.r_format.rd] =
680 				regs->cp0_epc + dec_insn.pc_inc +
681 				dec_insn.next_pc_inc;
682 			/* Fall through */
683 		case jr_op:
684 			*contpc = regs->regs[insn.r_format.rs];
685 			return 1;
686 		}
687 		break;
688 	case bcond_op:
689 		switch (insn.i_format.rt) {
690 		case bltzal_op:
691 		case bltzall_op:
692 			regs->regs[31] = regs->cp0_epc +
693 				dec_insn.pc_inc +
694 				dec_insn.next_pc_inc;
695 			/* Fall through */
696 		case bltz_op:
697 		case bltzl_op:
698 			if ((long)regs->regs[insn.i_format.rs] < 0)
699 				*contpc = regs->cp0_epc +
700 					dec_insn.pc_inc +
701 					(insn.i_format.simmediate << 2);
702 			else
703 				*contpc = regs->cp0_epc +
704 					dec_insn.pc_inc +
705 					dec_insn.next_pc_inc;
706 			return 1;
707 		case bgezal_op:
708 		case bgezall_op:
709 			regs->regs[31] = regs->cp0_epc +
710 				dec_insn.pc_inc +
711 				dec_insn.next_pc_inc;
712 			/* Fall through */
713 		case bgez_op:
714 		case bgezl_op:
715 			if ((long)regs->regs[insn.i_format.rs] >= 0)
716 				*contpc = regs->cp0_epc +
717 					dec_insn.pc_inc +
718 					(insn.i_format.simmediate << 2);
719 			else
720 				*contpc = regs->cp0_epc +
721 					dec_insn.pc_inc +
722 					dec_insn.next_pc_inc;
723 			return 1;
724 		}
725 		break;
726 	case jalx_op:
727 		set_isa16_mode(bit);
728 	case jal_op:
729 		regs->regs[31] = regs->cp0_epc +
730 			dec_insn.pc_inc +
731 			dec_insn.next_pc_inc;
732 		/* Fall through */
733 	case j_op:
734 		*contpc = regs->cp0_epc + dec_insn.pc_inc;
735 		*contpc >>= 28;
736 		*contpc <<= 28;
737 		*contpc |= (insn.j_format.target << 2);
738 		/* Set microMIPS mode bit: XOR for jalx. */
739 		*contpc ^= bit;
740 		return 1;
741 	case beq_op:
742 	case beql_op:
743 		if (regs->regs[insn.i_format.rs] ==
744 		    regs->regs[insn.i_format.rt])
745 			*contpc = regs->cp0_epc +
746 				dec_insn.pc_inc +
747 				(insn.i_format.simmediate << 2);
748 		else
749 			*contpc = regs->cp0_epc +
750 				dec_insn.pc_inc +
751 				dec_insn.next_pc_inc;
752 		return 1;
753 	case bne_op:
754 	case bnel_op:
755 		if (regs->regs[insn.i_format.rs] !=
756 		    regs->regs[insn.i_format.rt])
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 	case blez_op:
766 	case blezl_op:
767 		if ((long)regs->regs[insn.i_format.rs] <= 0)
768 			*contpc = regs->cp0_epc +
769 				dec_insn.pc_inc +
770 				(insn.i_format.simmediate << 2);
771 		else
772 			*contpc = regs->cp0_epc +
773 				dec_insn.pc_inc +
774 				dec_insn.next_pc_inc;
775 		return 1;
776 	case bgtz_op:
777 	case bgtzl_op:
778 		if ((long)regs->regs[insn.i_format.rs] > 0)
779 			*contpc = regs->cp0_epc +
780 				dec_insn.pc_inc +
781 				(insn.i_format.simmediate << 2);
782 		else
783 			*contpc = regs->cp0_epc +
784 				dec_insn.pc_inc +
785 				dec_insn.next_pc_inc;
786 		return 1;
787 #ifdef CONFIG_CPU_CAVIUM_OCTEON
788 	case lwc2_op: /* This is bbit0 on Octeon */
789 		if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
790 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
791 		else
792 			*contpc = regs->cp0_epc + 8;
793 		return 1;
794 	case ldc2_op: /* This is bbit032 on Octeon */
795 		if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
796 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
797 		else
798 			*contpc = regs->cp0_epc + 8;
799 		return 1;
800 	case swc2_op: /* This is bbit1 on Octeon */
801 		if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
802 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
803 		else
804 			*contpc = regs->cp0_epc + 8;
805 		return 1;
806 	case sdc2_op: /* This is bbit132 on Octeon */
807 		if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
808 			*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
809 		else
810 			*contpc = regs->cp0_epc + 8;
811 		return 1;
812 #endif
813 	case cop0_op:
814 	case cop1_op:
815 	case cop2_op:
816 	case cop1x_op:
817 		if (insn.i_format.rs == bc_op) {
818 			preempt_disable();
819 			if (is_fpu_owner())
820 				asm volatile("cfc1\t%0,$31" : "=r" (fcr31));
821 			else
822 				fcr31 = current->thread.fpu.fcr31;
823 			preempt_enable();
824 
825 			bit = (insn.i_format.rt >> 2);
826 			bit += (bit != 0);
827 			bit += 23;
828 			switch (insn.i_format.rt & 3) {
829 			case 0:	/* bc1f */
830 			case 2:	/* bc1fl */
831 				if (~fcr31 & (1 << bit))
832 					*contpc = regs->cp0_epc +
833 						dec_insn.pc_inc +
834 						(insn.i_format.simmediate << 2);
835 				else
836 					*contpc = regs->cp0_epc +
837 						dec_insn.pc_inc +
838 						dec_insn.next_pc_inc;
839 				return 1;
840 			case 1:	/* bc1t */
841 			case 3:	/* bc1tl */
842 				if (fcr31 & (1 << bit))
843 					*contpc = regs->cp0_epc +
844 						dec_insn.pc_inc +
845 						(insn.i_format.simmediate << 2);
846 				else
847 					*contpc = regs->cp0_epc +
848 						dec_insn.pc_inc +
849 						dec_insn.next_pc_inc;
850 				return 1;
851 			}
852 		}
853 		break;
854 	}
855 	return 0;
856 }
857 
858 /*
859  * In the Linux kernel, we support selection of FPR format on the
860  * basis of the Status.FR bit.	If an FPU is not present, the FR bit
861  * is hardwired to zero, which would imply a 32-bit FPU even for
862  * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
863  * FPU emu is slow and bulky and optimizing this function offers fairly
864  * sizeable benefits so we try to be clever and make this function return
865  * a constant whenever possible, that is on 64-bit kernels without O32
866  * compatibility enabled and on 32-bit without 64-bit FPU support.
867  */
868 static inline int cop1_64bit(struct pt_regs *xcp)
869 {
870 #if defined(CONFIG_64BIT) && !defined(CONFIG_MIPS32_O32)
871 	return 1;
872 #elif defined(CONFIG_32BIT) && !defined(CONFIG_MIPS_O32_FP64_SUPPORT)
873 	return 0;
874 #else
875 	return !test_thread_flag(TIF_32BIT_FPREGS);
876 #endif
877 }
878 
879 #define SIFROMREG(si, x) do {						\
880 	if (cop1_64bit(xcp))						\
881 		(si) = get_fpr32(&ctx->fpr[x], 0);			\
882 	else								\
883 		(si) = get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1);		\
884 } while (0)
885 
886 #define SITOREG(si, x) do {						\
887 	if (cop1_64bit(xcp)) {						\
888 		unsigned i;						\
889 		set_fpr32(&ctx->fpr[x], 0, si);				\
890 		for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)	\
891 			set_fpr32(&ctx->fpr[x], i, 0);			\
892 	} else {							\
893 		set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si);		\
894 	}								\
895 } while (0)
896 
897 #define SIFROMHREG(si, x)	((si) = get_fpr32(&ctx->fpr[x], 1))
898 
899 #define SITOHREG(si, x) do {						\
900 	unsigned i;							\
901 	set_fpr32(&ctx->fpr[x], 1, si);					\
902 	for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)		\
903 		set_fpr32(&ctx->fpr[x], i, 0);				\
904 } while (0)
905 
906 #define DIFROMREG(di, x) \
907 	((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0))
908 
909 #define DITOREG(di, x) do {						\
910 	unsigned fpr, i;						\
911 	fpr = (x) & ~(cop1_64bit(xcp) == 0);				\
912 	set_fpr64(&ctx->fpr[fpr], 0, di);				\
913 	for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++)		\
914 		set_fpr64(&ctx->fpr[fpr], i, 0);			\
915 } while (0)
916 
917 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
918 #define SPTOREG(sp, x)	SITOREG((sp).bits, x)
919 #define DPFROMREG(dp, x)	DIFROMREG((dp).bits, x)
920 #define DPTOREG(dp, x)	DITOREG((dp).bits, x)
921 
922 /*
923  * Emulate the single floating point instruction pointed at by EPC.
924  * Two instructions if the instruction is in a branch delay slot.
925  */
926 
927 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
928 		struct mm_decoded_insn dec_insn, void *__user *fault_addr)
929 {
930 	mips_instruction ir;
931 	unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
932 	unsigned int cond;
933 	int pc_inc;
934 
935 	/* XXX NEC Vr54xx bug workaround */
936 	if (xcp->cp0_cause & CAUSEF_BD) {
937 		if (dec_insn.micro_mips_mode) {
938 			if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
939 				xcp->cp0_cause &= ~CAUSEF_BD;
940 		} else {
941 			if (!isBranchInstr(xcp, dec_insn, &contpc))
942 				xcp->cp0_cause &= ~CAUSEF_BD;
943 		}
944 	}
945 
946 	if (xcp->cp0_cause & CAUSEF_BD) {
947 		/*
948 		 * The instruction to be emulated is in a branch delay slot
949 		 * which means that we have to	emulate the branch instruction
950 		 * BEFORE we do the cop1 instruction.
951 		 *
952 		 * This branch could be a COP1 branch, but in that case we
953 		 * would have had a trap for that instruction, and would not
954 		 * come through this route.
955 		 *
956 		 * Linux MIPS branch emulator operates on context, updating the
957 		 * cp0_epc.
958 		 */
959 		ir = dec_insn.next_insn;  /* process delay slot instr */
960 		pc_inc = dec_insn.next_pc_inc;
961 	} else {
962 		ir = dec_insn.insn;       /* process current instr */
963 		pc_inc = dec_insn.pc_inc;
964 	}
965 
966 	/*
967 	 * Since microMIPS FPU instructios are a subset of MIPS32 FPU
968 	 * instructions, we want to convert microMIPS FPU instructions
969 	 * into MIPS32 instructions so that we could reuse all of the
970 	 * FPU emulation code.
971 	 *
972 	 * NOTE: We cannot do this for branch instructions since they
973 	 *       are not a subset. Example: Cannot emulate a 16-bit
974 	 *       aligned target address with a MIPS32 instruction.
975 	 */
976 	if (dec_insn.micro_mips_mode) {
977 		/*
978 		 * If next instruction is a 16-bit instruction, then it
979 		 * it cannot be a FPU instruction. This could happen
980 		 * since we can be called for non-FPU instructions.
981 		 */
982 		if ((pc_inc == 2) ||
983 			(microMIPS32_to_MIPS32((union mips_instruction *)&ir)
984 			 == SIGILL))
985 			return SIGILL;
986 	}
987 
988       emul:
989 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
990 	MIPS_FPU_EMU_INC_STATS(emulated);
991 	switch (MIPSInst_OPCODE(ir)) {
992 	case ldc1_op:{
993 		u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
994 			MIPSInst_SIMM(ir));
995 		u64 val;
996 
997 		MIPS_FPU_EMU_INC_STATS(loads);
998 
999 		if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
1000 			MIPS_FPU_EMU_INC_STATS(errors);
1001 			*fault_addr = va;
1002 			return SIGBUS;
1003 		}
1004 		if (__get_user(val, va)) {
1005 			MIPS_FPU_EMU_INC_STATS(errors);
1006 			*fault_addr = va;
1007 			return SIGSEGV;
1008 		}
1009 		DITOREG(val, MIPSInst_RT(ir));
1010 		break;
1011 	}
1012 
1013 	case sdc1_op:{
1014 		u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1015 			MIPSInst_SIMM(ir));
1016 		u64 val;
1017 
1018 		MIPS_FPU_EMU_INC_STATS(stores);
1019 		DIFROMREG(val, MIPSInst_RT(ir));
1020 		if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
1021 			MIPS_FPU_EMU_INC_STATS(errors);
1022 			*fault_addr = va;
1023 			return SIGBUS;
1024 		}
1025 		if (__put_user(val, va)) {
1026 			MIPS_FPU_EMU_INC_STATS(errors);
1027 			*fault_addr = va;
1028 			return SIGSEGV;
1029 		}
1030 		break;
1031 	}
1032 
1033 	case lwc1_op:{
1034 		u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1035 			MIPSInst_SIMM(ir));
1036 		u32 val;
1037 
1038 		MIPS_FPU_EMU_INC_STATS(loads);
1039 		if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
1040 			MIPS_FPU_EMU_INC_STATS(errors);
1041 			*fault_addr = va;
1042 			return SIGBUS;
1043 		}
1044 		if (__get_user(val, va)) {
1045 			MIPS_FPU_EMU_INC_STATS(errors);
1046 			*fault_addr = va;
1047 			return SIGSEGV;
1048 		}
1049 		SITOREG(val, MIPSInst_RT(ir));
1050 		break;
1051 	}
1052 
1053 	case swc1_op:{
1054 		u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1055 			MIPSInst_SIMM(ir));
1056 		u32 val;
1057 
1058 		MIPS_FPU_EMU_INC_STATS(stores);
1059 		SIFROMREG(val, MIPSInst_RT(ir));
1060 		if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
1061 			MIPS_FPU_EMU_INC_STATS(errors);
1062 			*fault_addr = va;
1063 			return SIGBUS;
1064 		}
1065 		if (__put_user(val, va)) {
1066 			MIPS_FPU_EMU_INC_STATS(errors);
1067 			*fault_addr = va;
1068 			return SIGSEGV;
1069 		}
1070 		break;
1071 	}
1072 
1073 	case cop1_op:
1074 		switch (MIPSInst_RS(ir)) {
1075 
1076 #if defined(__mips64)
1077 		case dmfc_op:
1078 			/* copregister fs -> gpr[rt] */
1079 			if (MIPSInst_RT(ir) != 0) {
1080 				DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1081 					MIPSInst_RD(ir));
1082 			}
1083 			break;
1084 
1085 		case dmtc_op:
1086 			/* copregister fs <- rt */
1087 			DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1088 			break;
1089 #endif
1090 
1091 		case mfhc_op:
1092 			if (!cpu_has_mips_r2)
1093 				goto sigill;
1094 
1095 			/* copregister rd -> gpr[rt] */
1096 			if (MIPSInst_RT(ir) != 0) {
1097 				SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
1098 					MIPSInst_RD(ir));
1099 			}
1100 			break;
1101 
1102 		case mthc_op:
1103 			if (!cpu_has_mips_r2)
1104 				goto sigill;
1105 
1106 			/* copregister rd <- gpr[rt] */
1107 			SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1108 			break;
1109 
1110 		case mfc_op:
1111 			/* copregister rd -> gpr[rt] */
1112 			if (MIPSInst_RT(ir) != 0) {
1113 				SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1114 					MIPSInst_RD(ir));
1115 			}
1116 			break;
1117 
1118 		case mtc_op:
1119 			/* copregister rd <- rt */
1120 			SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1121 			break;
1122 
1123 		case cfc_op:{
1124 			/* cop control register rd -> gpr[rt] */
1125 			u32 value;
1126 
1127 			if (MIPSInst_RD(ir) == FPCREG_CSR) {
1128 				value = ctx->fcr31;
1129 				value = (value & ~FPU_CSR_RM) |
1130 					mips_rm[modeindex(value)];
1131 #ifdef CSRTRACE
1132 				printk("%p gpr[%d]<-csr=%08x\n",
1133 					(void *) (xcp->cp0_epc),
1134 					MIPSInst_RT(ir), value);
1135 #endif
1136 			}
1137 			else if (MIPSInst_RD(ir) == FPCREG_RID)
1138 				value = 0;
1139 			else
1140 				value = 0;
1141 			if (MIPSInst_RT(ir))
1142 				xcp->regs[MIPSInst_RT(ir)] = value;
1143 			break;
1144 		}
1145 
1146 		case ctc_op:{
1147 			/* copregister rd <- rt */
1148 			u32 value;
1149 
1150 			if (MIPSInst_RT(ir) == 0)
1151 				value = 0;
1152 			else
1153 				value = xcp->regs[MIPSInst_RT(ir)];
1154 
1155 			/* we only have one writable control reg
1156 			 */
1157 			if (MIPSInst_RD(ir) == FPCREG_CSR) {
1158 #ifdef CSRTRACE
1159 				printk("%p gpr[%d]->csr=%08x\n",
1160 					(void *) (xcp->cp0_epc),
1161 					MIPSInst_RT(ir), value);
1162 #endif
1163 
1164 				/*
1165 				 * Don't write reserved bits,
1166 				 * and convert to ieee library modes
1167 				 */
1168 				ctx->fcr31 = (value &
1169 						~(FPU_CSR_RSVD | FPU_CSR_RM)) |
1170 						ieee_rm[modeindex(value)];
1171 			}
1172 			if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1173 				return SIGFPE;
1174 			}
1175 			break;
1176 		}
1177 
1178 		case bc_op:{
1179 			int likely = 0;
1180 
1181 			if (xcp->cp0_cause & CAUSEF_BD)
1182 				return SIGILL;
1183 
1184 #if __mips >= 4
1185 			cond = ctx->fcr31 & fpucondbit[MIPSInst_RT(ir) >> 2];
1186 #else
1187 			cond = ctx->fcr31 & FPU_CSR_COND;
1188 #endif
1189 			switch (MIPSInst_RT(ir) & 3) {
1190 			case bcfl_op:
1191 				likely = 1;
1192 			case bcf_op:
1193 				cond = !cond;
1194 				break;
1195 			case bctl_op:
1196 				likely = 1;
1197 			case bct_op:
1198 				break;
1199 			default:
1200 				/* thats an illegal instruction */
1201 				return SIGILL;
1202 			}
1203 
1204 			xcp->cp0_cause |= CAUSEF_BD;
1205 			if (cond) {
1206 				/* branch taken: emulate dslot
1207 				 * instruction
1208 				 */
1209 				xcp->cp0_epc += dec_insn.pc_inc;
1210 
1211 				contpc = MIPSInst_SIMM(ir);
1212 				ir = dec_insn.next_insn;
1213 				if (dec_insn.micro_mips_mode) {
1214 					contpc = (xcp->cp0_epc + (contpc << 1));
1215 
1216 					/* If 16-bit instruction, not FPU. */
1217 					if ((dec_insn.next_pc_inc == 2) ||
1218 						(microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
1219 
1220 						/*
1221 						 * Since this instruction will
1222 						 * be put on the stack with
1223 						 * 32-bit words, get around
1224 						 * this problem by putting a
1225 						 * NOP16 as the second one.
1226 						 */
1227 						if (dec_insn.next_pc_inc == 2)
1228 							ir = (ir & (~0xffff)) | MM_NOP16;
1229 
1230 						/*
1231 						 * Single step the non-CP1
1232 						 * instruction in the dslot.
1233 						 */
1234 						return mips_dsemul(xcp, ir, contpc);
1235 					}
1236 				} else
1237 					contpc = (xcp->cp0_epc + (contpc << 2));
1238 
1239 				switch (MIPSInst_OPCODE(ir)) {
1240 				case lwc1_op:
1241 				case swc1_op:
1242 #if (__mips >= 2 || defined(__mips64))
1243 				case ldc1_op:
1244 				case sdc1_op:
1245 #endif
1246 				case cop1_op:
1247 #if __mips >= 4 && __mips != 32
1248 				case cop1x_op:
1249 #endif
1250 					/* its one of ours */
1251 					goto emul;
1252 #if __mips >= 4
1253 				case spec_op:
1254 					if (MIPSInst_FUNC(ir) == movc_op)
1255 						goto emul;
1256 					break;
1257 #endif
1258 				}
1259 
1260 				/*
1261 				 * Single step the non-cp1
1262 				 * instruction in the dslot
1263 				 */
1264 				return mips_dsemul(xcp, ir, contpc);
1265 			}
1266 			else {
1267 				/* branch not taken */
1268 				if (likely) {
1269 					/*
1270 					 * branch likely nullifies
1271 					 * dslot if not taken
1272 					 */
1273 					xcp->cp0_epc += dec_insn.pc_inc;
1274 					contpc += dec_insn.pc_inc;
1275 					/*
1276 					 * else continue & execute
1277 					 * dslot as normal insn
1278 					 */
1279 				}
1280 			}
1281 			break;
1282 		}
1283 
1284 		default:
1285 			if (!(MIPSInst_RS(ir) & 0x10))
1286 				return SIGILL;
1287 			{
1288 				int sig;
1289 
1290 				/* a real fpu computation instruction */
1291 				if ((sig = fpu_emu(xcp, ctx, ir)))
1292 					return sig;
1293 			}
1294 		}
1295 		break;
1296 
1297 #if __mips >= 4 && __mips != 32
1298 	case cop1x_op:{
1299 		int sig = fpux_emu(xcp, ctx, ir, fault_addr);
1300 		if (sig)
1301 			return sig;
1302 		break;
1303 	}
1304 #endif
1305 
1306 #if __mips >= 4
1307 	case spec_op:
1308 		if (MIPSInst_FUNC(ir) != movc_op)
1309 			return SIGILL;
1310 		cond = fpucondbit[MIPSInst_RT(ir) >> 2];
1311 		if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
1312 			xcp->regs[MIPSInst_RD(ir)] =
1313 				xcp->regs[MIPSInst_RS(ir)];
1314 		break;
1315 #endif
1316 
1317 	default:
1318 sigill:
1319 		return SIGILL;
1320 	}
1321 
1322 	/* we did it !! */
1323 	xcp->cp0_epc = contpc;
1324 	xcp->cp0_cause &= ~CAUSEF_BD;
1325 
1326 	return 0;
1327 }
1328 
1329 /*
1330  * Conversion table from MIPS compare ops 48-63
1331  * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
1332  */
1333 static const unsigned char cmptab[8] = {
1334 	0,			/* cmp_0 (sig) cmp_sf */
1335 	IEEE754_CUN,		/* cmp_un (sig) cmp_ngle */
1336 	IEEE754_CEQ,		/* cmp_eq (sig) cmp_seq */
1337 	IEEE754_CEQ | IEEE754_CUN,	/* cmp_ueq (sig) cmp_ngl  */
1338 	IEEE754_CLT,		/* cmp_olt (sig) cmp_lt */
1339 	IEEE754_CLT | IEEE754_CUN,	/* cmp_ult (sig) cmp_nge */
1340 	IEEE754_CLT | IEEE754_CEQ,	/* cmp_ole (sig) cmp_le */
1341 	IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN,	/* cmp_ule (sig) cmp_ngt */
1342 };
1343 
1344 
1345 #if __mips >= 4 && __mips != 32
1346 
1347 /*
1348  * Additional MIPS4 instructions
1349  */
1350 
1351 #define DEF3OP(name, p, f1, f2, f3) \
1352 static ieee754##p fpemu_##p##_##name(ieee754##p r, ieee754##p s, \
1353     ieee754##p t) \
1354 { \
1355 	struct _ieee754_csr ieee754_csr_save; \
1356 	s = f1(s, t); \
1357 	ieee754_csr_save = ieee754_csr; \
1358 	s = f2(s, r); \
1359 	ieee754_csr_save.cx |= ieee754_csr.cx; \
1360 	ieee754_csr_save.sx |= ieee754_csr.sx; \
1361 	s = f3(s); \
1362 	ieee754_csr.cx |= ieee754_csr_save.cx; \
1363 	ieee754_csr.sx |= ieee754_csr_save.sx; \
1364 	return s; \
1365 }
1366 
1367 static ieee754dp fpemu_dp_recip(ieee754dp d)
1368 {
1369 	return ieee754dp_div(ieee754dp_one(0), d);
1370 }
1371 
1372 static ieee754dp fpemu_dp_rsqrt(ieee754dp d)
1373 {
1374 	return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
1375 }
1376 
1377 static ieee754sp fpemu_sp_recip(ieee754sp s)
1378 {
1379 	return ieee754sp_div(ieee754sp_one(0), s);
1380 }
1381 
1382 static ieee754sp fpemu_sp_rsqrt(ieee754sp s)
1383 {
1384 	return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
1385 }
1386 
1387 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
1388 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
1389 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
1390 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
1391 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
1392 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
1393 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
1394 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
1395 
1396 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1397 	mips_instruction ir, void *__user *fault_addr)
1398 {
1399 	unsigned rcsr = 0;	/* resulting csr */
1400 
1401 	MIPS_FPU_EMU_INC_STATS(cp1xops);
1402 
1403 	switch (MIPSInst_FMA_FFMT(ir)) {
1404 	case s_fmt:{		/* 0 */
1405 
1406 		ieee754sp(*handler) (ieee754sp, ieee754sp, ieee754sp);
1407 		ieee754sp fd, fr, fs, ft;
1408 		u32 __user *va;
1409 		u32 val;
1410 
1411 		switch (MIPSInst_FUNC(ir)) {
1412 		case lwxc1_op:
1413 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1414 				xcp->regs[MIPSInst_FT(ir)]);
1415 
1416 			MIPS_FPU_EMU_INC_STATS(loads);
1417 			if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
1418 				MIPS_FPU_EMU_INC_STATS(errors);
1419 				*fault_addr = va;
1420 				return SIGBUS;
1421 			}
1422 			if (__get_user(val, va)) {
1423 				MIPS_FPU_EMU_INC_STATS(errors);
1424 				*fault_addr = va;
1425 				return SIGSEGV;
1426 			}
1427 			SITOREG(val, MIPSInst_FD(ir));
1428 			break;
1429 
1430 		case swxc1_op:
1431 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1432 				xcp->regs[MIPSInst_FT(ir)]);
1433 
1434 			MIPS_FPU_EMU_INC_STATS(stores);
1435 
1436 			SIFROMREG(val, MIPSInst_FS(ir));
1437 			if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
1438 				MIPS_FPU_EMU_INC_STATS(errors);
1439 				*fault_addr = va;
1440 				return SIGBUS;
1441 			}
1442 			if (put_user(val, va)) {
1443 				MIPS_FPU_EMU_INC_STATS(errors);
1444 				*fault_addr = va;
1445 				return SIGSEGV;
1446 			}
1447 			break;
1448 
1449 		case madd_s_op:
1450 			handler = fpemu_sp_madd;
1451 			goto scoptop;
1452 		case msub_s_op:
1453 			handler = fpemu_sp_msub;
1454 			goto scoptop;
1455 		case nmadd_s_op:
1456 			handler = fpemu_sp_nmadd;
1457 			goto scoptop;
1458 		case nmsub_s_op:
1459 			handler = fpemu_sp_nmsub;
1460 			goto scoptop;
1461 
1462 		      scoptop:
1463 			SPFROMREG(fr, MIPSInst_FR(ir));
1464 			SPFROMREG(fs, MIPSInst_FS(ir));
1465 			SPFROMREG(ft, MIPSInst_FT(ir));
1466 			fd = (*handler) (fr, fs, ft);
1467 			SPTOREG(fd, MIPSInst_FD(ir));
1468 
1469 		      copcsr:
1470 			if (ieee754_cxtest(IEEE754_INEXACT))
1471 				rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1472 			if (ieee754_cxtest(IEEE754_UNDERFLOW))
1473 				rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1474 			if (ieee754_cxtest(IEEE754_OVERFLOW))
1475 				rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1476 			if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
1477 				rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1478 
1479 			ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1480 			if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1481 				/*printk ("SIGFPE: fpu csr = %08x\n",
1482 				   ctx->fcr31); */
1483 				return SIGFPE;
1484 			}
1485 
1486 			break;
1487 
1488 		default:
1489 			return SIGILL;
1490 		}
1491 		break;
1492 	}
1493 
1494 	case d_fmt:{		/* 1 */
1495 		ieee754dp(*handler) (ieee754dp, ieee754dp, ieee754dp);
1496 		ieee754dp fd, fr, fs, ft;
1497 		u64 __user *va;
1498 		u64 val;
1499 
1500 		switch (MIPSInst_FUNC(ir)) {
1501 		case ldxc1_op:
1502 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1503 				xcp->regs[MIPSInst_FT(ir)]);
1504 
1505 			MIPS_FPU_EMU_INC_STATS(loads);
1506 			if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
1507 				MIPS_FPU_EMU_INC_STATS(errors);
1508 				*fault_addr = va;
1509 				return SIGBUS;
1510 			}
1511 			if (__get_user(val, va)) {
1512 				MIPS_FPU_EMU_INC_STATS(errors);
1513 				*fault_addr = va;
1514 				return SIGSEGV;
1515 			}
1516 			DITOREG(val, MIPSInst_FD(ir));
1517 			break;
1518 
1519 		case sdxc1_op:
1520 			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1521 				xcp->regs[MIPSInst_FT(ir)]);
1522 
1523 			MIPS_FPU_EMU_INC_STATS(stores);
1524 			DIFROMREG(val, MIPSInst_FS(ir));
1525 			if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
1526 				MIPS_FPU_EMU_INC_STATS(errors);
1527 				*fault_addr = va;
1528 				return SIGBUS;
1529 			}
1530 			if (__put_user(val, va)) {
1531 				MIPS_FPU_EMU_INC_STATS(errors);
1532 				*fault_addr = va;
1533 				return SIGSEGV;
1534 			}
1535 			break;
1536 
1537 		case madd_d_op:
1538 			handler = fpemu_dp_madd;
1539 			goto dcoptop;
1540 		case msub_d_op:
1541 			handler = fpemu_dp_msub;
1542 			goto dcoptop;
1543 		case nmadd_d_op:
1544 			handler = fpemu_dp_nmadd;
1545 			goto dcoptop;
1546 		case nmsub_d_op:
1547 			handler = fpemu_dp_nmsub;
1548 			goto dcoptop;
1549 
1550 		      dcoptop:
1551 			DPFROMREG(fr, MIPSInst_FR(ir));
1552 			DPFROMREG(fs, MIPSInst_FS(ir));
1553 			DPFROMREG(ft, MIPSInst_FT(ir));
1554 			fd = (*handler) (fr, fs, ft);
1555 			DPTOREG(fd, MIPSInst_FD(ir));
1556 			goto copcsr;
1557 
1558 		default:
1559 			return SIGILL;
1560 		}
1561 		break;
1562 	}
1563 
1564 	case 0x3:
1565 		if (MIPSInst_FUNC(ir) != pfetch_op)
1566 			return SIGILL;
1567 
1568 		/* ignore prefx operation */
1569 		break;
1570 
1571 	default:
1572 		return SIGILL;
1573 	}
1574 
1575 	return 0;
1576 }
1577 #endif
1578 
1579 
1580 
1581 /*
1582  * Emulate a single COP1 arithmetic instruction.
1583  */
1584 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1585 	mips_instruction ir)
1586 {
1587 	int rfmt;		/* resulting format */
1588 	unsigned rcsr = 0;	/* resulting csr */
1589 	unsigned cond;
1590 	union {
1591 		ieee754dp d;
1592 		ieee754sp s;
1593 		int w;
1594 #ifdef __mips64
1595 		s64 l;
1596 #endif
1597 	} rv;			/* resulting value */
1598 
1599 	MIPS_FPU_EMU_INC_STATS(cp1ops);
1600 	switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
1601 	case s_fmt:{		/* 0 */
1602 		union {
1603 			ieee754sp(*b) (ieee754sp, ieee754sp);
1604 			ieee754sp(*u) (ieee754sp);
1605 		} handler;
1606 
1607 		switch (MIPSInst_FUNC(ir)) {
1608 			/* binary ops */
1609 		case fadd_op:
1610 			handler.b = ieee754sp_add;
1611 			goto scopbop;
1612 		case fsub_op:
1613 			handler.b = ieee754sp_sub;
1614 			goto scopbop;
1615 		case fmul_op:
1616 			handler.b = ieee754sp_mul;
1617 			goto scopbop;
1618 		case fdiv_op:
1619 			handler.b = ieee754sp_div;
1620 			goto scopbop;
1621 
1622 			/* unary  ops */
1623 #if __mips >= 2 || defined(__mips64)
1624 		case fsqrt_op:
1625 			handler.u = ieee754sp_sqrt;
1626 			goto scopuop;
1627 #endif
1628 #if __mips >= 4 && __mips != 32
1629 		case frsqrt_op:
1630 			handler.u = fpemu_sp_rsqrt;
1631 			goto scopuop;
1632 		case frecip_op:
1633 			handler.u = fpemu_sp_recip;
1634 			goto scopuop;
1635 #endif
1636 #if __mips >= 4
1637 		case fmovc_op:
1638 			cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1639 			if (((ctx->fcr31 & cond) != 0) !=
1640 				((MIPSInst_FT(ir) & 1) != 0))
1641 				return 0;
1642 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1643 			break;
1644 		case fmovz_op:
1645 			if (xcp->regs[MIPSInst_FT(ir)] != 0)
1646 				return 0;
1647 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1648 			break;
1649 		case fmovn_op:
1650 			if (xcp->regs[MIPSInst_FT(ir)] == 0)
1651 				return 0;
1652 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1653 			break;
1654 #endif
1655 		case fabs_op:
1656 			handler.u = ieee754sp_abs;
1657 			goto scopuop;
1658 		case fneg_op:
1659 			handler.u = ieee754sp_neg;
1660 			goto scopuop;
1661 		case fmov_op:
1662 			/* an easy one */
1663 			SPFROMREG(rv.s, MIPSInst_FS(ir));
1664 			goto copcsr;
1665 
1666 			/* binary op on handler */
1667 		      scopbop:
1668 			{
1669 				ieee754sp fs, ft;
1670 
1671 				SPFROMREG(fs, MIPSInst_FS(ir));
1672 				SPFROMREG(ft, MIPSInst_FT(ir));
1673 
1674 				rv.s = (*handler.b) (fs, ft);
1675 				goto copcsr;
1676 			}
1677 		      scopuop:
1678 			{
1679 				ieee754sp fs;
1680 
1681 				SPFROMREG(fs, MIPSInst_FS(ir));
1682 				rv.s = (*handler.u) (fs);
1683 				goto copcsr;
1684 			}
1685 		      copcsr:
1686 			if (ieee754_cxtest(IEEE754_INEXACT))
1687 				rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1688 			if (ieee754_cxtest(IEEE754_UNDERFLOW))
1689 				rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1690 			if (ieee754_cxtest(IEEE754_OVERFLOW))
1691 				rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1692 			if (ieee754_cxtest(IEEE754_ZERO_DIVIDE))
1693 				rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
1694 			if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
1695 				rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1696 			break;
1697 
1698 			/* unary conv ops */
1699 		case fcvts_op:
1700 			return SIGILL;	/* not defined */
1701 		case fcvtd_op:{
1702 			ieee754sp fs;
1703 
1704 			SPFROMREG(fs, MIPSInst_FS(ir));
1705 			rv.d = ieee754dp_fsp(fs);
1706 			rfmt = d_fmt;
1707 			goto copcsr;
1708 		}
1709 		case fcvtw_op:{
1710 			ieee754sp fs;
1711 
1712 			SPFROMREG(fs, MIPSInst_FS(ir));
1713 			rv.w = ieee754sp_tint(fs);
1714 			rfmt = w_fmt;
1715 			goto copcsr;
1716 		}
1717 
1718 #if __mips >= 2 || defined(__mips64)
1719 		case fround_op:
1720 		case ftrunc_op:
1721 		case fceil_op:
1722 		case ffloor_op:{
1723 			unsigned int oldrm = ieee754_csr.rm;
1724 			ieee754sp fs;
1725 
1726 			SPFROMREG(fs, MIPSInst_FS(ir));
1727 			ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1728 			rv.w = ieee754sp_tint(fs);
1729 			ieee754_csr.rm = oldrm;
1730 			rfmt = w_fmt;
1731 			goto copcsr;
1732 		}
1733 #endif /* __mips >= 2 */
1734 
1735 #if defined(__mips64)
1736 		case fcvtl_op:{
1737 			ieee754sp fs;
1738 
1739 			SPFROMREG(fs, MIPSInst_FS(ir));
1740 			rv.l = ieee754sp_tlong(fs);
1741 			rfmt = l_fmt;
1742 			goto copcsr;
1743 		}
1744 
1745 		case froundl_op:
1746 		case ftruncl_op:
1747 		case fceill_op:
1748 		case ffloorl_op:{
1749 			unsigned int oldrm = ieee754_csr.rm;
1750 			ieee754sp fs;
1751 
1752 			SPFROMREG(fs, MIPSInst_FS(ir));
1753 			ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1754 			rv.l = ieee754sp_tlong(fs);
1755 			ieee754_csr.rm = oldrm;
1756 			rfmt = l_fmt;
1757 			goto copcsr;
1758 		}
1759 #endif /* defined(__mips64) */
1760 
1761 		default:
1762 			if (MIPSInst_FUNC(ir) >= fcmp_op) {
1763 				unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1764 				ieee754sp fs, ft;
1765 
1766 				SPFROMREG(fs, MIPSInst_FS(ir));
1767 				SPFROMREG(ft, MIPSInst_FT(ir));
1768 				rv.w = ieee754sp_cmp(fs, ft,
1769 					cmptab[cmpop & 0x7], cmpop & 0x8);
1770 				rfmt = -1;
1771 				if ((cmpop & 0x8) && ieee754_cxtest
1772 					(IEEE754_INVALID_OPERATION))
1773 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1774 				else
1775 					goto copcsr;
1776 
1777 			}
1778 			else {
1779 				return SIGILL;
1780 			}
1781 			break;
1782 		}
1783 		break;
1784 	}
1785 
1786 	case d_fmt:{
1787 		union {
1788 			ieee754dp(*b) (ieee754dp, ieee754dp);
1789 			ieee754dp(*u) (ieee754dp);
1790 		} handler;
1791 
1792 		switch (MIPSInst_FUNC(ir)) {
1793 			/* binary ops */
1794 		case fadd_op:
1795 			handler.b = ieee754dp_add;
1796 			goto dcopbop;
1797 		case fsub_op:
1798 			handler.b = ieee754dp_sub;
1799 			goto dcopbop;
1800 		case fmul_op:
1801 			handler.b = ieee754dp_mul;
1802 			goto dcopbop;
1803 		case fdiv_op:
1804 			handler.b = ieee754dp_div;
1805 			goto dcopbop;
1806 
1807 			/* unary  ops */
1808 #if __mips >= 2 || defined(__mips64)
1809 		case fsqrt_op:
1810 			handler.u = ieee754dp_sqrt;
1811 			goto dcopuop;
1812 #endif
1813 #if __mips >= 4 && __mips != 32
1814 		case frsqrt_op:
1815 			handler.u = fpemu_dp_rsqrt;
1816 			goto dcopuop;
1817 		case frecip_op:
1818 			handler.u = fpemu_dp_recip;
1819 			goto dcopuop;
1820 #endif
1821 #if __mips >= 4
1822 		case fmovc_op:
1823 			cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1824 			if (((ctx->fcr31 & cond) != 0) !=
1825 				((MIPSInst_FT(ir) & 1) != 0))
1826 				return 0;
1827 			DPFROMREG(rv.d, MIPSInst_FS(ir));
1828 			break;
1829 		case fmovz_op:
1830 			if (xcp->regs[MIPSInst_FT(ir)] != 0)
1831 				return 0;
1832 			DPFROMREG(rv.d, MIPSInst_FS(ir));
1833 			break;
1834 		case fmovn_op:
1835 			if (xcp->regs[MIPSInst_FT(ir)] == 0)
1836 				return 0;
1837 			DPFROMREG(rv.d, MIPSInst_FS(ir));
1838 			break;
1839 #endif
1840 		case fabs_op:
1841 			handler.u = ieee754dp_abs;
1842 			goto dcopuop;
1843 
1844 		case fneg_op:
1845 			handler.u = ieee754dp_neg;
1846 			goto dcopuop;
1847 
1848 		case fmov_op:
1849 			/* an easy one */
1850 			DPFROMREG(rv.d, MIPSInst_FS(ir));
1851 			goto copcsr;
1852 
1853 			/* binary op on handler */
1854 		      dcopbop:{
1855 				ieee754dp fs, ft;
1856 
1857 				DPFROMREG(fs, MIPSInst_FS(ir));
1858 				DPFROMREG(ft, MIPSInst_FT(ir));
1859 
1860 				rv.d = (*handler.b) (fs, ft);
1861 				goto copcsr;
1862 			}
1863 		      dcopuop:{
1864 				ieee754dp fs;
1865 
1866 				DPFROMREG(fs, MIPSInst_FS(ir));
1867 				rv.d = (*handler.u) (fs);
1868 				goto copcsr;
1869 			}
1870 
1871 			/* unary conv ops */
1872 		case fcvts_op:{
1873 			ieee754dp fs;
1874 
1875 			DPFROMREG(fs, MIPSInst_FS(ir));
1876 			rv.s = ieee754sp_fdp(fs);
1877 			rfmt = s_fmt;
1878 			goto copcsr;
1879 		}
1880 		case fcvtd_op:
1881 			return SIGILL;	/* not defined */
1882 
1883 		case fcvtw_op:{
1884 			ieee754dp fs;
1885 
1886 			DPFROMREG(fs, MIPSInst_FS(ir));
1887 			rv.w = ieee754dp_tint(fs);	/* wrong */
1888 			rfmt = w_fmt;
1889 			goto copcsr;
1890 		}
1891 
1892 #if __mips >= 2 || defined(__mips64)
1893 		case fround_op:
1894 		case ftrunc_op:
1895 		case fceil_op:
1896 		case ffloor_op:{
1897 			unsigned int oldrm = ieee754_csr.rm;
1898 			ieee754dp fs;
1899 
1900 			DPFROMREG(fs, MIPSInst_FS(ir));
1901 			ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1902 			rv.w = ieee754dp_tint(fs);
1903 			ieee754_csr.rm = oldrm;
1904 			rfmt = w_fmt;
1905 			goto copcsr;
1906 		}
1907 #endif
1908 
1909 #if defined(__mips64)
1910 		case fcvtl_op:{
1911 			ieee754dp fs;
1912 
1913 			DPFROMREG(fs, MIPSInst_FS(ir));
1914 			rv.l = ieee754dp_tlong(fs);
1915 			rfmt = l_fmt;
1916 			goto copcsr;
1917 		}
1918 
1919 		case froundl_op:
1920 		case ftruncl_op:
1921 		case fceill_op:
1922 		case ffloorl_op:{
1923 			unsigned int oldrm = ieee754_csr.rm;
1924 			ieee754dp fs;
1925 
1926 			DPFROMREG(fs, MIPSInst_FS(ir));
1927 			ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1928 			rv.l = ieee754dp_tlong(fs);
1929 			ieee754_csr.rm = oldrm;
1930 			rfmt = l_fmt;
1931 			goto copcsr;
1932 		}
1933 #endif /* __mips >= 3 */
1934 
1935 		default:
1936 			if (MIPSInst_FUNC(ir) >= fcmp_op) {
1937 				unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1938 				ieee754dp fs, ft;
1939 
1940 				DPFROMREG(fs, MIPSInst_FS(ir));
1941 				DPFROMREG(ft, MIPSInst_FT(ir));
1942 				rv.w = ieee754dp_cmp(fs, ft,
1943 					cmptab[cmpop & 0x7], cmpop & 0x8);
1944 				rfmt = -1;
1945 				if ((cmpop & 0x8)
1946 					&&
1947 					ieee754_cxtest
1948 					(IEEE754_INVALID_OPERATION))
1949 					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1950 				else
1951 					goto copcsr;
1952 
1953 			}
1954 			else {
1955 				return SIGILL;
1956 			}
1957 			break;
1958 		}
1959 		break;
1960 	}
1961 
1962 	case w_fmt:{
1963 		ieee754sp fs;
1964 
1965 		switch (MIPSInst_FUNC(ir)) {
1966 		case fcvts_op:
1967 			/* convert word to single precision real */
1968 			SPFROMREG(fs, MIPSInst_FS(ir));
1969 			rv.s = ieee754sp_fint(fs.bits);
1970 			rfmt = s_fmt;
1971 			goto copcsr;
1972 		case fcvtd_op:
1973 			/* convert word to double precision real */
1974 			SPFROMREG(fs, MIPSInst_FS(ir));
1975 			rv.d = ieee754dp_fint(fs.bits);
1976 			rfmt = d_fmt;
1977 			goto copcsr;
1978 		default:
1979 			return SIGILL;
1980 		}
1981 		break;
1982 	}
1983 
1984 #if defined(__mips64)
1985 	case l_fmt:{
1986 		u64 bits;
1987 		DIFROMREG(bits, MIPSInst_FS(ir));
1988 
1989 		switch (MIPSInst_FUNC(ir)) {
1990 		case fcvts_op:
1991 			/* convert long to single precision real */
1992 			rv.s = ieee754sp_flong(bits);
1993 			rfmt = s_fmt;
1994 			goto copcsr;
1995 		case fcvtd_op:
1996 			/* convert long to double precision real */
1997 			rv.d = ieee754dp_flong(bits);
1998 			rfmt = d_fmt;
1999 			goto copcsr;
2000 		default:
2001 			return SIGILL;
2002 		}
2003 		break;
2004 	}
2005 #endif
2006 
2007 	default:
2008 		return SIGILL;
2009 	}
2010 
2011 	/*
2012 	 * Update the fpu CSR register for this operation.
2013 	 * If an exception is required, generate a tidy SIGFPE exception,
2014 	 * without updating the result register.
2015 	 * Note: cause exception bits do not accumulate, they are rewritten
2016 	 * for each op; only the flag/sticky bits accumulate.
2017 	 */
2018 	ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
2019 	if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
2020 		/*printk ("SIGFPE: fpu csr = %08x\n",ctx->fcr31); */
2021 		return SIGFPE;
2022 	}
2023 
2024 	/*
2025 	 * Now we can safely write the result back to the register file.
2026 	 */
2027 	switch (rfmt) {
2028 	case -1:{
2029 #if __mips >= 4
2030 		cond = fpucondbit[MIPSInst_FD(ir) >> 2];
2031 #else
2032 		cond = FPU_CSR_COND;
2033 #endif
2034 		if (rv.w)
2035 			ctx->fcr31 |= cond;
2036 		else
2037 			ctx->fcr31 &= ~cond;
2038 		break;
2039 	}
2040 	case d_fmt:
2041 		DPTOREG(rv.d, MIPSInst_FD(ir));
2042 		break;
2043 	case s_fmt:
2044 		SPTOREG(rv.s, MIPSInst_FD(ir));
2045 		break;
2046 	case w_fmt:
2047 		SITOREG(rv.w, MIPSInst_FD(ir));
2048 		break;
2049 #if defined(__mips64)
2050 	case l_fmt:
2051 		DITOREG(rv.l, MIPSInst_FD(ir));
2052 		break;
2053 #endif
2054 	default:
2055 		return SIGILL;
2056 	}
2057 
2058 	return 0;
2059 }
2060 
2061 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
2062 	int has_fpu, void *__user *fault_addr)
2063 {
2064 	unsigned long oldepc, prevepc;
2065 	struct mm_decoded_insn dec_insn;
2066 	u16 instr[4];
2067 	u16 *instr_ptr;
2068 	int sig = 0;
2069 
2070 	oldepc = xcp->cp0_epc;
2071 	do {
2072 		prevepc = xcp->cp0_epc;
2073 
2074 		if (get_isa16_mode(prevepc) && cpu_has_mmips) {
2075 			/*
2076 			 * Get next 2 microMIPS instructions and convert them
2077 			 * into 32-bit instructions.
2078 			 */
2079 			if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
2080 			    (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
2081 			    (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
2082 			    (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
2083 				MIPS_FPU_EMU_INC_STATS(errors);
2084 				return SIGBUS;
2085 			}
2086 			instr_ptr = instr;
2087 
2088 			/* Get first instruction. */
2089 			if (mm_insn_16bit(*instr_ptr)) {
2090 				/* Duplicate the half-word. */
2091 				dec_insn.insn = (*instr_ptr << 16) |
2092 					(*instr_ptr);
2093 				/* 16-bit instruction. */
2094 				dec_insn.pc_inc = 2;
2095 				instr_ptr += 1;
2096 			} else {
2097 				dec_insn.insn = (*instr_ptr << 16) |
2098 					*(instr_ptr+1);
2099 				/* 32-bit instruction. */
2100 				dec_insn.pc_inc = 4;
2101 				instr_ptr += 2;
2102 			}
2103 			/* Get second instruction. */
2104 			if (mm_insn_16bit(*instr_ptr)) {
2105 				/* Duplicate the half-word. */
2106 				dec_insn.next_insn = (*instr_ptr << 16) |
2107 					(*instr_ptr);
2108 				/* 16-bit instruction. */
2109 				dec_insn.next_pc_inc = 2;
2110 			} else {
2111 				dec_insn.next_insn = (*instr_ptr << 16) |
2112 					*(instr_ptr+1);
2113 				/* 32-bit instruction. */
2114 				dec_insn.next_pc_inc = 4;
2115 			}
2116 			dec_insn.micro_mips_mode = 1;
2117 		} else {
2118 			if ((get_user(dec_insn.insn,
2119 			    (mips_instruction __user *) xcp->cp0_epc)) ||
2120 			    (get_user(dec_insn.next_insn,
2121 			    (mips_instruction __user *)(xcp->cp0_epc+4)))) {
2122 				MIPS_FPU_EMU_INC_STATS(errors);
2123 				return SIGBUS;
2124 			}
2125 			dec_insn.pc_inc = 4;
2126 			dec_insn.next_pc_inc = 4;
2127 			dec_insn.micro_mips_mode = 0;
2128 		}
2129 
2130 		if ((dec_insn.insn == 0) ||
2131 		   ((dec_insn.pc_inc == 2) &&
2132 		   ((dec_insn.insn & 0xffff) == MM_NOP16)))
2133 			xcp->cp0_epc += dec_insn.pc_inc;	/* Skip NOPs */
2134 		else {
2135 			/*
2136 			 * The 'ieee754_csr' is an alias of
2137 			 * ctx->fcr31.	No need to copy ctx->fcr31 to
2138 			 * ieee754_csr.	 But ieee754_csr.rm is ieee
2139 			 * library modes. (not mips rounding mode)
2140 			 */
2141 			/* convert to ieee library modes */
2142 			ieee754_csr.rm = ieee_rm[ieee754_csr.rm];
2143 			sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
2144 			/* revert to mips rounding mode */
2145 			ieee754_csr.rm = mips_rm[ieee754_csr.rm];
2146 		}
2147 
2148 		if (has_fpu)
2149 			break;
2150 		if (sig)
2151 			break;
2152 
2153 		cond_resched();
2154 	} while (xcp->cp0_epc > prevepc);
2155 
2156 	/* SIGILL indicates a non-fpu instruction */
2157 	if (sig == SIGILL && xcp->cp0_epc != oldepc)
2158 		/* but if epc has advanced, then ignore it */
2159 		sig = 0;
2160 
2161 	return sig;
2162 }
2163 
2164 #ifdef CONFIG_DEBUG_FS
2165 
2166 static int fpuemu_stat_get(void *data, u64 *val)
2167 {
2168 	int cpu;
2169 	unsigned long sum = 0;
2170 	for_each_online_cpu(cpu) {
2171 		struct mips_fpu_emulator_stats *ps;
2172 		local_t *pv;
2173 		ps = &per_cpu(fpuemustats, cpu);
2174 		pv = (void *)ps + (unsigned long)data;
2175 		sum += local_read(pv);
2176 	}
2177 	*val = sum;
2178 	return 0;
2179 }
2180 DEFINE_SIMPLE_ATTRIBUTE(fops_fpuemu_stat, fpuemu_stat_get, NULL, "%llu\n");
2181 
2182 extern struct dentry *mips_debugfs_dir;
2183 static int __init debugfs_fpuemu(void)
2184 {
2185 	struct dentry *d, *dir;
2186 
2187 	if (!mips_debugfs_dir)
2188 		return -ENODEV;
2189 	dir = debugfs_create_dir("fpuemustats", mips_debugfs_dir);
2190 	if (!dir)
2191 		return -ENOMEM;
2192 
2193 #define FPU_STAT_CREATE(M)						\
2194 	do {								\
2195 		d = debugfs_create_file(#M , S_IRUGO, dir,		\
2196 			(void *)offsetof(struct mips_fpu_emulator_stats, M), \
2197 			&fops_fpuemu_stat);				\
2198 		if (!d)							\
2199 			return -ENOMEM;					\
2200 	} while (0)
2201 
2202 	FPU_STAT_CREATE(emulated);
2203 	FPU_STAT_CREATE(loads);
2204 	FPU_STAT_CREATE(stores);
2205 	FPU_STAT_CREATE(cp1ops);
2206 	FPU_STAT_CREATE(cp1xops);
2207 	FPU_STAT_CREATE(errors);
2208 
2209 	return 0;
2210 }
2211 __initcall(debugfs_fpuemu);
2212 #endif
2213