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Merge branches 'acpica-fixes', 'acpi-pci-fixes' and 'acpi-debug-fixes'
[mirror_ubuntu-artful-kernel.git] / arch / mips / math-emu / cp1emu.c
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/kconfig.h>
39 #include <linux/percpu-defs.h>
40 #include <linux/perf_event.h>
41
42 #include <asm/branch.h>
43 #include <asm/inst.h>
44 #include <asm/ptrace.h>
45 #include <asm/signal.h>
46 #include <asm/uaccess.h>
47
48 #include <asm/cpu-info.h>
49 #include <asm/processor.h>
50 #include <asm/fpu_emulator.h>
51 #include <asm/fpu.h>
52 #include <asm/mips-r2-to-r6-emul.h>
53
54 #include "ieee754.h"
55
56 /* Function which emulates a floating point instruction. */
57
58 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
59 mips_instruction);
60
61 static int fpux_emu(struct pt_regs *,
62 struct mips_fpu_struct *, mips_instruction, void *__user *);
63
64 /* Control registers */
65
66 #define FPCREG_RID 0 /* $0 = revision id */
67 #define FPCREG_FCCR 25 /* $25 = fccr */
68 #define FPCREG_FEXR 26 /* $26 = fexr */
69 #define FPCREG_FENR 28 /* $28 = fenr */
70 #define FPCREG_CSR 31 /* $31 = csr */
71
72 /* convert condition code register number to csr bit */
73 const unsigned int fpucondbit[8] = {
74 FPU_CSR_COND,
75 FPU_CSR_COND1,
76 FPU_CSR_COND2,
77 FPU_CSR_COND3,
78 FPU_CSR_COND4,
79 FPU_CSR_COND5,
80 FPU_CSR_COND6,
81 FPU_CSR_COND7
82 };
83
84 /* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
85 static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
86 static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
87 static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
88 static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
89
90 /*
91 * This functions translates a 32-bit microMIPS instruction
92 * into a 32-bit MIPS32 instruction. Returns 0 on success
93 * and SIGILL otherwise.
94 */
95 static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
96 {
97 union mips_instruction insn = *insn_ptr;
98 union mips_instruction mips32_insn = insn;
99 int func, fmt, op;
100
101 switch (insn.mm_i_format.opcode) {
102 case mm_ldc132_op:
103 mips32_insn.mm_i_format.opcode = ldc1_op;
104 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
105 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
106 break;
107 case mm_lwc132_op:
108 mips32_insn.mm_i_format.opcode = lwc1_op;
109 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
110 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
111 break;
112 case mm_sdc132_op:
113 mips32_insn.mm_i_format.opcode = sdc1_op;
114 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
115 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
116 break;
117 case mm_swc132_op:
118 mips32_insn.mm_i_format.opcode = swc1_op;
119 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
120 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
121 break;
122 case mm_pool32i_op:
123 /* NOTE: offset is << by 1 if in microMIPS mode. */
124 if ((insn.mm_i_format.rt == mm_bc1f_op) ||
125 (insn.mm_i_format.rt == mm_bc1t_op)) {
126 mips32_insn.fb_format.opcode = cop1_op;
127 mips32_insn.fb_format.bc = bc_op;
128 mips32_insn.fb_format.flag =
129 (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
130 } else
131 return SIGILL;
132 break;
133 case mm_pool32f_op:
134 switch (insn.mm_fp0_format.func) {
135 case mm_32f_01_op:
136 case mm_32f_11_op:
137 case mm_32f_02_op:
138 case mm_32f_12_op:
139 case mm_32f_41_op:
140 case mm_32f_51_op:
141 case mm_32f_42_op:
142 case mm_32f_52_op:
143 op = insn.mm_fp0_format.func;
144 if (op == mm_32f_01_op)
145 func = madd_s_op;
146 else if (op == mm_32f_11_op)
147 func = madd_d_op;
148 else if (op == mm_32f_02_op)
149 func = nmadd_s_op;
150 else if (op == mm_32f_12_op)
151 func = nmadd_d_op;
152 else if (op == mm_32f_41_op)
153 func = msub_s_op;
154 else if (op == mm_32f_51_op)
155 func = msub_d_op;
156 else if (op == mm_32f_42_op)
157 func = nmsub_s_op;
158 else
159 func = nmsub_d_op;
160 mips32_insn.fp6_format.opcode = cop1x_op;
161 mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
162 mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
163 mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
164 mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
165 mips32_insn.fp6_format.func = func;
166 break;
167 case mm_32f_10_op:
168 func = -1; /* Invalid */
169 op = insn.mm_fp5_format.op & 0x7;
170 if (op == mm_ldxc1_op)
171 func = ldxc1_op;
172 else if (op == mm_sdxc1_op)
173 func = sdxc1_op;
174 else if (op == mm_lwxc1_op)
175 func = lwxc1_op;
176 else if (op == mm_swxc1_op)
177 func = swxc1_op;
178
179 if (func != -1) {
180 mips32_insn.r_format.opcode = cop1x_op;
181 mips32_insn.r_format.rs =
182 insn.mm_fp5_format.base;
183 mips32_insn.r_format.rt =
184 insn.mm_fp5_format.index;
185 mips32_insn.r_format.rd = 0;
186 mips32_insn.r_format.re = insn.mm_fp5_format.fd;
187 mips32_insn.r_format.func = func;
188 } else
189 return SIGILL;
190 break;
191 case mm_32f_40_op:
192 op = -1; /* Invalid */
193 if (insn.mm_fp2_format.op == mm_fmovt_op)
194 op = 1;
195 else if (insn.mm_fp2_format.op == mm_fmovf_op)
196 op = 0;
197 if (op != -1) {
198 mips32_insn.fp0_format.opcode = cop1_op;
199 mips32_insn.fp0_format.fmt =
200 sdps_format[insn.mm_fp2_format.fmt];
201 mips32_insn.fp0_format.ft =
202 (insn.mm_fp2_format.cc<<2) + op;
203 mips32_insn.fp0_format.fs =
204 insn.mm_fp2_format.fs;
205 mips32_insn.fp0_format.fd =
206 insn.mm_fp2_format.fd;
207 mips32_insn.fp0_format.func = fmovc_op;
208 } else
209 return SIGILL;
210 break;
211 case mm_32f_60_op:
212 func = -1; /* Invalid */
213 if (insn.mm_fp0_format.op == mm_fadd_op)
214 func = fadd_op;
215 else if (insn.mm_fp0_format.op == mm_fsub_op)
216 func = fsub_op;
217 else if (insn.mm_fp0_format.op == mm_fmul_op)
218 func = fmul_op;
219 else if (insn.mm_fp0_format.op == mm_fdiv_op)
220 func = fdiv_op;
221 if (func != -1) {
222 mips32_insn.fp0_format.opcode = cop1_op;
223 mips32_insn.fp0_format.fmt =
224 sdps_format[insn.mm_fp0_format.fmt];
225 mips32_insn.fp0_format.ft =
226 insn.mm_fp0_format.ft;
227 mips32_insn.fp0_format.fs =
228 insn.mm_fp0_format.fs;
229 mips32_insn.fp0_format.fd =
230 insn.mm_fp0_format.fd;
231 mips32_insn.fp0_format.func = func;
232 } else
233 return SIGILL;
234 break;
235 case mm_32f_70_op:
236 func = -1; /* Invalid */
237 if (insn.mm_fp0_format.op == mm_fmovn_op)
238 func = fmovn_op;
239 else if (insn.mm_fp0_format.op == mm_fmovz_op)
240 func = fmovz_op;
241 if (func != -1) {
242 mips32_insn.fp0_format.opcode = cop1_op;
243 mips32_insn.fp0_format.fmt =
244 sdps_format[insn.mm_fp0_format.fmt];
245 mips32_insn.fp0_format.ft =
246 insn.mm_fp0_format.ft;
247 mips32_insn.fp0_format.fs =
248 insn.mm_fp0_format.fs;
249 mips32_insn.fp0_format.fd =
250 insn.mm_fp0_format.fd;
251 mips32_insn.fp0_format.func = func;
252 } else
253 return SIGILL;
254 break;
255 case mm_32f_73_op: /* POOL32FXF */
256 switch (insn.mm_fp1_format.op) {
257 case mm_movf0_op:
258 case mm_movf1_op:
259 case mm_movt0_op:
260 case mm_movt1_op:
261 if ((insn.mm_fp1_format.op & 0x7f) ==
262 mm_movf0_op)
263 op = 0;
264 else
265 op = 1;
266 mips32_insn.r_format.opcode = spec_op;
267 mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
268 mips32_insn.r_format.rt =
269 (insn.mm_fp4_format.cc << 2) + op;
270 mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
271 mips32_insn.r_format.re = 0;
272 mips32_insn.r_format.func = movc_op;
273 break;
274 case mm_fcvtd0_op:
275 case mm_fcvtd1_op:
276 case mm_fcvts0_op:
277 case mm_fcvts1_op:
278 if ((insn.mm_fp1_format.op & 0x7f) ==
279 mm_fcvtd0_op) {
280 func = fcvtd_op;
281 fmt = swl_format[insn.mm_fp3_format.fmt];
282 } else {
283 func = fcvts_op;
284 fmt = dwl_format[insn.mm_fp3_format.fmt];
285 }
286 mips32_insn.fp0_format.opcode = cop1_op;
287 mips32_insn.fp0_format.fmt = fmt;
288 mips32_insn.fp0_format.ft = 0;
289 mips32_insn.fp0_format.fs =
290 insn.mm_fp3_format.fs;
291 mips32_insn.fp0_format.fd =
292 insn.mm_fp3_format.rt;
293 mips32_insn.fp0_format.func = func;
294 break;
295 case mm_fmov0_op:
296 case mm_fmov1_op:
297 case mm_fabs0_op:
298 case mm_fabs1_op:
299 case mm_fneg0_op:
300 case mm_fneg1_op:
301 if ((insn.mm_fp1_format.op & 0x7f) ==
302 mm_fmov0_op)
303 func = fmov_op;
304 else if ((insn.mm_fp1_format.op & 0x7f) ==
305 mm_fabs0_op)
306 func = fabs_op;
307 else
308 func = fneg_op;
309 mips32_insn.fp0_format.opcode = cop1_op;
310 mips32_insn.fp0_format.fmt =
311 sdps_format[insn.mm_fp3_format.fmt];
312 mips32_insn.fp0_format.ft = 0;
313 mips32_insn.fp0_format.fs =
314 insn.mm_fp3_format.fs;
315 mips32_insn.fp0_format.fd =
316 insn.mm_fp3_format.rt;
317 mips32_insn.fp0_format.func = func;
318 break;
319 case mm_ffloorl_op:
320 case mm_ffloorw_op:
321 case mm_fceill_op:
322 case mm_fceilw_op:
323 case mm_ftruncl_op:
324 case mm_ftruncw_op:
325 case mm_froundl_op:
326 case mm_froundw_op:
327 case mm_fcvtl_op:
328 case mm_fcvtw_op:
329 if (insn.mm_fp1_format.op == mm_ffloorl_op)
330 func = ffloorl_op;
331 else if (insn.mm_fp1_format.op == mm_ffloorw_op)
332 func = ffloor_op;
333 else if (insn.mm_fp1_format.op == mm_fceill_op)
334 func = fceill_op;
335 else if (insn.mm_fp1_format.op == mm_fceilw_op)
336 func = fceil_op;
337 else if (insn.mm_fp1_format.op == mm_ftruncl_op)
338 func = ftruncl_op;
339 else if (insn.mm_fp1_format.op == mm_ftruncw_op)
340 func = ftrunc_op;
341 else if (insn.mm_fp1_format.op == mm_froundl_op)
342 func = froundl_op;
343 else if (insn.mm_fp1_format.op == mm_froundw_op)
344 func = fround_op;
345 else if (insn.mm_fp1_format.op == mm_fcvtl_op)
346 func = fcvtl_op;
347 else
348 func = fcvtw_op;
349 mips32_insn.fp0_format.opcode = cop1_op;
350 mips32_insn.fp0_format.fmt =
351 sd_format[insn.mm_fp1_format.fmt];
352 mips32_insn.fp0_format.ft = 0;
353 mips32_insn.fp0_format.fs =
354 insn.mm_fp1_format.fs;
355 mips32_insn.fp0_format.fd =
356 insn.mm_fp1_format.rt;
357 mips32_insn.fp0_format.func = func;
358 break;
359 case mm_frsqrt_op:
360 case mm_fsqrt_op:
361 case mm_frecip_op:
362 if (insn.mm_fp1_format.op == mm_frsqrt_op)
363 func = frsqrt_op;
364 else if (insn.mm_fp1_format.op == mm_fsqrt_op)
365 func = fsqrt_op;
366 else
367 func = frecip_op;
368 mips32_insn.fp0_format.opcode = cop1_op;
369 mips32_insn.fp0_format.fmt =
370 sdps_format[insn.mm_fp1_format.fmt];
371 mips32_insn.fp0_format.ft = 0;
372 mips32_insn.fp0_format.fs =
373 insn.mm_fp1_format.fs;
374 mips32_insn.fp0_format.fd =
375 insn.mm_fp1_format.rt;
376 mips32_insn.fp0_format.func = func;
377 break;
378 case mm_mfc1_op:
379 case mm_mtc1_op:
380 case mm_cfc1_op:
381 case mm_ctc1_op:
382 case mm_mfhc1_op:
383 case mm_mthc1_op:
384 if (insn.mm_fp1_format.op == mm_mfc1_op)
385 op = mfc_op;
386 else if (insn.mm_fp1_format.op == mm_mtc1_op)
387 op = mtc_op;
388 else if (insn.mm_fp1_format.op == mm_cfc1_op)
389 op = cfc_op;
390 else if (insn.mm_fp1_format.op == mm_ctc1_op)
391 op = ctc_op;
392 else if (insn.mm_fp1_format.op == mm_mfhc1_op)
393 op = mfhc_op;
394 else
395 op = mthc_op;
396 mips32_insn.fp1_format.opcode = cop1_op;
397 mips32_insn.fp1_format.op = op;
398 mips32_insn.fp1_format.rt =
399 insn.mm_fp1_format.rt;
400 mips32_insn.fp1_format.fs =
401 insn.mm_fp1_format.fs;
402 mips32_insn.fp1_format.fd = 0;
403 mips32_insn.fp1_format.func = 0;
404 break;
405 default:
406 return SIGILL;
407 }
408 break;
409 case mm_32f_74_op: /* c.cond.fmt */
410 mips32_insn.fp0_format.opcode = cop1_op;
411 mips32_insn.fp0_format.fmt =
412 sdps_format[insn.mm_fp4_format.fmt];
413 mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
414 mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
415 mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
416 mips32_insn.fp0_format.func =
417 insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
418 break;
419 default:
420 return SIGILL;
421 }
422 break;
423 default:
424 return SIGILL;
425 }
426
427 *insn_ptr = mips32_insn;
428 return 0;
429 }
430
431 /*
432 * Redundant with logic already in kernel/branch.c,
433 * embedded in compute_return_epc. At some point,
434 * a single subroutine should be used across both
435 * modules.
436 */
437 static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
438 unsigned long *contpc)
439 {
440 union mips_instruction insn = (union mips_instruction)dec_insn.insn;
441 unsigned int fcr31;
442 unsigned int bit = 0;
443
444 switch (insn.i_format.opcode) {
445 case spec_op:
446 switch (insn.r_format.func) {
447 case jalr_op:
448 if (insn.r_format.rd != 0) {
449 regs->regs[insn.r_format.rd] =
450 regs->cp0_epc + dec_insn.pc_inc +
451 dec_insn.next_pc_inc;
452 }
453 /* Fall through */
454 case jr_op:
455 /* For R6, JR already emulated in jalr_op */
456 if (NO_R6EMU && insn.r_format.func == jr_op)
457 break;
458 *contpc = regs->regs[insn.r_format.rs];
459 return 1;
460 }
461 break;
462 case bcond_op:
463 switch (insn.i_format.rt) {
464 case bltzal_op:
465 case bltzall_op:
466 if (NO_R6EMU && (insn.i_format.rs ||
467 insn.i_format.rt == bltzall_op))
468 break;
469
470 regs->regs[31] = regs->cp0_epc +
471 dec_insn.pc_inc +
472 dec_insn.next_pc_inc;
473 /* Fall through */
474 case bltzl_op:
475 if (NO_R6EMU)
476 break;
477 case bltz_op:
478 if ((long)regs->regs[insn.i_format.rs] < 0)
479 *contpc = regs->cp0_epc +
480 dec_insn.pc_inc +
481 (insn.i_format.simmediate << 2);
482 else
483 *contpc = regs->cp0_epc +
484 dec_insn.pc_inc +
485 dec_insn.next_pc_inc;
486 return 1;
487 case bgezal_op:
488 case bgezall_op:
489 if (NO_R6EMU && (insn.i_format.rs ||
490 insn.i_format.rt == bgezall_op))
491 break;
492
493 regs->regs[31] = regs->cp0_epc +
494 dec_insn.pc_inc +
495 dec_insn.next_pc_inc;
496 /* Fall through */
497 case bgezl_op:
498 if (NO_R6EMU)
499 break;
500 case bgez_op:
501 if ((long)regs->regs[insn.i_format.rs] >= 0)
502 *contpc = regs->cp0_epc +
503 dec_insn.pc_inc +
504 (insn.i_format.simmediate << 2);
505 else
506 *contpc = regs->cp0_epc +
507 dec_insn.pc_inc +
508 dec_insn.next_pc_inc;
509 return 1;
510 }
511 break;
512 case jalx_op:
513 set_isa16_mode(bit);
514 case jal_op:
515 regs->regs[31] = regs->cp0_epc +
516 dec_insn.pc_inc +
517 dec_insn.next_pc_inc;
518 /* Fall through */
519 case j_op:
520 *contpc = regs->cp0_epc + dec_insn.pc_inc;
521 *contpc >>= 28;
522 *contpc <<= 28;
523 *contpc |= (insn.j_format.target << 2);
524 /* Set microMIPS mode bit: XOR for jalx. */
525 *contpc ^= bit;
526 return 1;
527 case beql_op:
528 if (NO_R6EMU)
529 break;
530 case beq_op:
531 if (regs->regs[insn.i_format.rs] ==
532 regs->regs[insn.i_format.rt])
533 *contpc = regs->cp0_epc +
534 dec_insn.pc_inc +
535 (insn.i_format.simmediate << 2);
536 else
537 *contpc = regs->cp0_epc +
538 dec_insn.pc_inc +
539 dec_insn.next_pc_inc;
540 return 1;
541 case bnel_op:
542 if (NO_R6EMU)
543 break;
544 case bne_op:
545 if (regs->regs[insn.i_format.rs] !=
546 regs->regs[insn.i_format.rt])
547 *contpc = regs->cp0_epc +
548 dec_insn.pc_inc +
549 (insn.i_format.simmediate << 2);
550 else
551 *contpc = regs->cp0_epc +
552 dec_insn.pc_inc +
553 dec_insn.next_pc_inc;
554 return 1;
555 case blezl_op:
556 if (!insn.i_format.rt && NO_R6EMU)
557 break;
558 case blez_op:
559
560 /*
561 * Compact branches for R6 for the
562 * blez and blezl opcodes.
563 * BLEZ | rs = 0 | rt != 0 == BLEZALC
564 * BLEZ | rs = rt != 0 == BGEZALC
565 * BLEZ | rs != 0 | rt != 0 == BGEUC
566 * BLEZL | rs = 0 | rt != 0 == BLEZC
567 * BLEZL | rs = rt != 0 == BGEZC
568 * BLEZL | rs != 0 | rt != 0 == BGEC
569 *
570 * For real BLEZ{,L}, rt is always 0.
571 */
572 if (cpu_has_mips_r6 && insn.i_format.rt) {
573 if ((insn.i_format.opcode == blez_op) &&
574 ((!insn.i_format.rs && insn.i_format.rt) ||
575 (insn.i_format.rs == insn.i_format.rt)))
576 regs->regs[31] = regs->cp0_epc +
577 dec_insn.pc_inc;
578 *contpc = regs->cp0_epc + dec_insn.pc_inc +
579 dec_insn.next_pc_inc;
580
581 return 1;
582 }
583 if ((long)regs->regs[insn.i_format.rs] <= 0)
584 *contpc = regs->cp0_epc +
585 dec_insn.pc_inc +
586 (insn.i_format.simmediate << 2);
587 else
588 *contpc = regs->cp0_epc +
589 dec_insn.pc_inc +
590 dec_insn.next_pc_inc;
591 return 1;
592 case bgtzl_op:
593 if (!insn.i_format.rt && NO_R6EMU)
594 break;
595 case bgtz_op:
596 /*
597 * Compact branches for R6 for the
598 * bgtz and bgtzl opcodes.
599 * BGTZ | rs = 0 | rt != 0 == BGTZALC
600 * BGTZ | rs = rt != 0 == BLTZALC
601 * BGTZ | rs != 0 | rt != 0 == BLTUC
602 * BGTZL | rs = 0 | rt != 0 == BGTZC
603 * BGTZL | rs = rt != 0 == BLTZC
604 * BGTZL | rs != 0 | rt != 0 == BLTC
605 *
606 * *ZALC varint for BGTZ &&& rt != 0
607 * For real GTZ{,L}, rt is always 0.
608 */
609 if (cpu_has_mips_r6 && insn.i_format.rt) {
610 if ((insn.i_format.opcode == blez_op) &&
611 ((!insn.i_format.rs && insn.i_format.rt) ||
612 (insn.i_format.rs == insn.i_format.rt)))
613 regs->regs[31] = regs->cp0_epc +
614 dec_insn.pc_inc;
615 *contpc = regs->cp0_epc + dec_insn.pc_inc +
616 dec_insn.next_pc_inc;
617
618 return 1;
619 }
620
621 if ((long)regs->regs[insn.i_format.rs] > 0)
622 *contpc = regs->cp0_epc +
623 dec_insn.pc_inc +
624 (insn.i_format.simmediate << 2);
625 else
626 *contpc = regs->cp0_epc +
627 dec_insn.pc_inc +
628 dec_insn.next_pc_inc;
629 return 1;
630 case cbcond0_op:
631 case cbcond1_op:
632 if (!cpu_has_mips_r6)
633 break;
634 if (insn.i_format.rt && !insn.i_format.rs)
635 regs->regs[31] = regs->cp0_epc + 4;
636 *contpc = regs->cp0_epc + dec_insn.pc_inc +
637 dec_insn.next_pc_inc;
638
639 return 1;
640 #ifdef CONFIG_CPU_CAVIUM_OCTEON
641 case lwc2_op: /* This is bbit0 on Octeon */
642 if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
643 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
644 else
645 *contpc = regs->cp0_epc + 8;
646 return 1;
647 case ldc2_op: /* This is bbit032 on Octeon */
648 if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
649 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
650 else
651 *contpc = regs->cp0_epc + 8;
652 return 1;
653 case swc2_op: /* This is bbit1 on Octeon */
654 if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
655 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
656 else
657 *contpc = regs->cp0_epc + 8;
658 return 1;
659 case sdc2_op: /* This is bbit132 on Octeon */
660 if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
661 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
662 else
663 *contpc = regs->cp0_epc + 8;
664 return 1;
665 #else
666 case bc6_op:
667 /*
668 * Only valid for MIPS R6 but we can still end up
669 * here from a broken userland so just tell emulator
670 * this is not a branch and let it break later on.
671 */
672 if (!cpu_has_mips_r6)
673 break;
674 *contpc = regs->cp0_epc + dec_insn.pc_inc +
675 dec_insn.next_pc_inc;
676
677 return 1;
678 case balc6_op:
679 if (!cpu_has_mips_r6)
680 break;
681 regs->regs[31] = regs->cp0_epc + 4;
682 *contpc = regs->cp0_epc + dec_insn.pc_inc +
683 dec_insn.next_pc_inc;
684
685 return 1;
686 case beqzcjic_op:
687 if (!cpu_has_mips_r6)
688 break;
689 *contpc = regs->cp0_epc + dec_insn.pc_inc +
690 dec_insn.next_pc_inc;
691
692 return 1;
693 case bnezcjialc_op:
694 if (!cpu_has_mips_r6)
695 break;
696 if (!insn.i_format.rs)
697 regs->regs[31] = regs->cp0_epc + 4;
698 *contpc = regs->cp0_epc + dec_insn.pc_inc +
699 dec_insn.next_pc_inc;
700
701 return 1;
702 #endif
703 case cop0_op:
704 case cop1_op:
705 /* Need to check for R6 bc1nez and bc1eqz branches */
706 if (cpu_has_mips_r6 &&
707 ((insn.i_format.rs == bc1eqz_op) ||
708 (insn.i_format.rs == bc1nez_op))) {
709 bit = 0;
710 switch (insn.i_format.rs) {
711 case bc1eqz_op:
712 if (get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1)
713 bit = 1;
714 break;
715 case bc1nez_op:
716 if (!(get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1))
717 bit = 1;
718 break;
719 }
720 if (bit)
721 *contpc = regs->cp0_epc +
722 dec_insn.pc_inc +
723 (insn.i_format.simmediate << 2);
724 else
725 *contpc = regs->cp0_epc +
726 dec_insn.pc_inc +
727 dec_insn.next_pc_inc;
728
729 return 1;
730 }
731 /* R2/R6 compatible cop1 instruction. Fall through */
732 case cop2_op:
733 case cop1x_op:
734 if (insn.i_format.rs == bc_op) {
735 preempt_disable();
736 if (is_fpu_owner())
737 fcr31 = read_32bit_cp1_register(CP1_STATUS);
738 else
739 fcr31 = current->thread.fpu.fcr31;
740 preempt_enable();
741
742 bit = (insn.i_format.rt >> 2);
743 bit += (bit != 0);
744 bit += 23;
745 switch (insn.i_format.rt & 3) {
746 case 0: /* bc1f */
747 case 2: /* bc1fl */
748 if (~fcr31 & (1 << bit))
749 *contpc = regs->cp0_epc +
750 dec_insn.pc_inc +
751 (insn.i_format.simmediate << 2);
752 else
753 *contpc = regs->cp0_epc +
754 dec_insn.pc_inc +
755 dec_insn.next_pc_inc;
756 return 1;
757 case 1: /* bc1t */
758 case 3: /* bc1tl */
759 if (fcr31 & (1 << bit))
760 *contpc = regs->cp0_epc +
761 dec_insn.pc_inc +
762 (insn.i_format.simmediate << 2);
763 else
764 *contpc = regs->cp0_epc +
765 dec_insn.pc_inc +
766 dec_insn.next_pc_inc;
767 return 1;
768 }
769 }
770 break;
771 }
772 return 0;
773 }
774
775 /*
776 * In the Linux kernel, we support selection of FPR format on the
777 * basis of the Status.FR bit. If an FPU is not present, the FR bit
778 * is hardwired to zero, which would imply a 32-bit FPU even for
779 * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
780 * FPU emu is slow and bulky and optimizing this function offers fairly
781 * sizeable benefits so we try to be clever and make this function return
782 * a constant whenever possible, that is on 64-bit kernels without O32
783 * compatibility enabled and on 32-bit without 64-bit FPU support.
784 */
785 static inline int cop1_64bit(struct pt_regs *xcp)
786 {
787 if (config_enabled(CONFIG_64BIT) && !config_enabled(CONFIG_MIPS32_O32))
788 return 1;
789 else if (config_enabled(CONFIG_32BIT) &&
790 !config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT))
791 return 0;
792
793 return !test_thread_flag(TIF_32BIT_FPREGS);
794 }
795
796 static inline bool hybrid_fprs(void)
797 {
798 return test_thread_flag(TIF_HYBRID_FPREGS);
799 }
800
801 #define SIFROMREG(si, x) \
802 do { \
803 if (cop1_64bit(xcp) && !hybrid_fprs()) \
804 (si) = (int)get_fpr32(&ctx->fpr[x], 0); \
805 else \
806 (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \
807 } while (0)
808
809 #define SITOREG(si, x) \
810 do { \
811 if (cop1_64bit(xcp) && !hybrid_fprs()) { \
812 unsigned i; \
813 set_fpr32(&ctx->fpr[x], 0, si); \
814 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
815 set_fpr32(&ctx->fpr[x], i, 0); \
816 } else { \
817 set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si); \
818 } \
819 } while (0)
820
821 #define SIFROMHREG(si, x) ((si) = (int)get_fpr32(&ctx->fpr[x], 1))
822
823 #define SITOHREG(si, x) \
824 do { \
825 unsigned i; \
826 set_fpr32(&ctx->fpr[x], 1, si); \
827 for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
828 set_fpr32(&ctx->fpr[x], i, 0); \
829 } while (0)
830
831 #define DIFROMREG(di, x) \
832 ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0))
833
834 #define DITOREG(di, x) \
835 do { \
836 unsigned fpr, i; \
837 fpr = (x) & ~(cop1_64bit(xcp) == 0); \
838 set_fpr64(&ctx->fpr[fpr], 0, di); \
839 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++) \
840 set_fpr64(&ctx->fpr[fpr], i, 0); \
841 } while (0)
842
843 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
844 #define SPTOREG(sp, x) SITOREG((sp).bits, x)
845 #define DPFROMREG(dp, x) DIFROMREG((dp).bits, x)
846 #define DPTOREG(dp, x) DITOREG((dp).bits, x)
847
848 /*
849 * Emulate a CFC1 instruction.
850 */
851 static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
852 mips_instruction ir)
853 {
854 u32 fcr31 = ctx->fcr31;
855 u32 value = 0;
856
857 switch (MIPSInst_RD(ir)) {
858 case FPCREG_CSR:
859 value = fcr31;
860 pr_debug("%p gpr[%d]<-csr=%08x\n",
861 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
862 break;
863
864 case FPCREG_FENR:
865 if (!cpu_has_mips_r)
866 break;
867 value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
868 MIPS_FENR_FS;
869 value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM);
870 pr_debug("%p gpr[%d]<-enr=%08x\n",
871 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
872 break;
873
874 case FPCREG_FEXR:
875 if (!cpu_has_mips_r)
876 break;
877 value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
878 pr_debug("%p gpr[%d]<-exr=%08x\n",
879 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
880 break;
881
882 case FPCREG_FCCR:
883 if (!cpu_has_mips_r)
884 break;
885 value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
886 MIPS_FCCR_COND0;
887 value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
888 (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0);
889 pr_debug("%p gpr[%d]<-ccr=%08x\n",
890 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
891 break;
892
893 case FPCREG_RID:
894 value = boot_cpu_data.fpu_id;
895 break;
896
897 default:
898 break;
899 }
900
901 if (MIPSInst_RT(ir))
902 xcp->regs[MIPSInst_RT(ir)] = value;
903 }
904
905 /*
906 * Emulate a CTC1 instruction.
907 */
908 static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
909 mips_instruction ir)
910 {
911 u32 fcr31 = ctx->fcr31;
912 u32 value;
913 u32 mask;
914
915 if (MIPSInst_RT(ir) == 0)
916 value = 0;
917 else
918 value = xcp->regs[MIPSInst_RT(ir)];
919
920 switch (MIPSInst_RD(ir)) {
921 case FPCREG_CSR:
922 pr_debug("%p gpr[%d]->csr=%08x\n",
923 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
924
925 /* Preserve read-only bits. */
926 mask = boot_cpu_data.fpu_msk31;
927 fcr31 = (value & ~mask) | (fcr31 & mask);
928 break;
929
930 case FPCREG_FENR:
931 if (!cpu_has_mips_r)
932 break;
933 pr_debug("%p gpr[%d]->enr=%08x\n",
934 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
935 fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM);
936 fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
937 FPU_CSR_FS;
938 fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM);
939 break;
940
941 case FPCREG_FEXR:
942 if (!cpu_has_mips_r)
943 break;
944 pr_debug("%p gpr[%d]->exr=%08x\n",
945 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
946 fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S);
947 fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
948 break;
949
950 case FPCREG_FCCR:
951 if (!cpu_has_mips_r)
952 break;
953 pr_debug("%p gpr[%d]->ccr=%08x\n",
954 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
955 fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND);
956 fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
957 FPU_CSR_COND;
958 fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
959 FPU_CSR_CONDX;
960 break;
961
962 default:
963 break;
964 }
965
966 ctx->fcr31 = fcr31;
967 }
968
969 /*
970 * Emulate the single floating point instruction pointed at by EPC.
971 * Two instructions if the instruction is in a branch delay slot.
972 */
973
974 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
975 struct mm_decoded_insn dec_insn, void *__user *fault_addr)
976 {
977 unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
978 unsigned int cond, cbit, bit0;
979 mips_instruction ir;
980 int likely, pc_inc;
981 union fpureg *fpr;
982 u32 __user *wva;
983 u64 __user *dva;
984 u32 wval;
985 u64 dval;
986 int sig;
987
988 /*
989 * These are giving gcc a gentle hint about what to expect in
990 * dec_inst in order to do better optimization.
991 */
992 if (!cpu_has_mmips && dec_insn.micro_mips_mode)
993 unreachable();
994
995 /* XXX NEC Vr54xx bug workaround */
996 if (delay_slot(xcp)) {
997 if (dec_insn.micro_mips_mode) {
998 if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
999 clear_delay_slot(xcp);
1000 } else {
1001 if (!isBranchInstr(xcp, dec_insn, &contpc))
1002 clear_delay_slot(xcp);
1003 }
1004 }
1005
1006 if (delay_slot(xcp)) {
1007 /*
1008 * The instruction to be emulated is in a branch delay slot
1009 * which means that we have to emulate the branch instruction
1010 * BEFORE we do the cop1 instruction.
1011 *
1012 * This branch could be a COP1 branch, but in that case we
1013 * would have had a trap for that instruction, and would not
1014 * come through this route.
1015 *
1016 * Linux MIPS branch emulator operates on context, updating the
1017 * cp0_epc.
1018 */
1019 ir = dec_insn.next_insn; /* process delay slot instr */
1020 pc_inc = dec_insn.next_pc_inc;
1021 } else {
1022 ir = dec_insn.insn; /* process current instr */
1023 pc_inc = dec_insn.pc_inc;
1024 }
1025
1026 /*
1027 * Since microMIPS FPU instructios are a subset of MIPS32 FPU
1028 * instructions, we want to convert microMIPS FPU instructions
1029 * into MIPS32 instructions so that we could reuse all of the
1030 * FPU emulation code.
1031 *
1032 * NOTE: We cannot do this for branch instructions since they
1033 * are not a subset. Example: Cannot emulate a 16-bit
1034 * aligned target address with a MIPS32 instruction.
1035 */
1036 if (dec_insn.micro_mips_mode) {
1037 /*
1038 * If next instruction is a 16-bit instruction, then it
1039 * it cannot be a FPU instruction. This could happen
1040 * since we can be called for non-FPU instructions.
1041 */
1042 if ((pc_inc == 2) ||
1043 (microMIPS32_to_MIPS32((union mips_instruction *)&ir)
1044 == SIGILL))
1045 return SIGILL;
1046 }
1047
1048 emul:
1049 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
1050 MIPS_FPU_EMU_INC_STATS(emulated);
1051 switch (MIPSInst_OPCODE(ir)) {
1052 case ldc1_op:
1053 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1054 MIPSInst_SIMM(ir));
1055 MIPS_FPU_EMU_INC_STATS(loads);
1056
1057 if (!access_ok(VERIFY_READ, dva, sizeof(u64))) {
1058 MIPS_FPU_EMU_INC_STATS(errors);
1059 *fault_addr = dva;
1060 return SIGBUS;
1061 }
1062 if (__get_user(dval, dva)) {
1063 MIPS_FPU_EMU_INC_STATS(errors);
1064 *fault_addr = dva;
1065 return SIGSEGV;
1066 }
1067 DITOREG(dval, MIPSInst_RT(ir));
1068 break;
1069
1070 case sdc1_op:
1071 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1072 MIPSInst_SIMM(ir));
1073 MIPS_FPU_EMU_INC_STATS(stores);
1074 DIFROMREG(dval, MIPSInst_RT(ir));
1075 if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) {
1076 MIPS_FPU_EMU_INC_STATS(errors);
1077 *fault_addr = dva;
1078 return SIGBUS;
1079 }
1080 if (__put_user(dval, dva)) {
1081 MIPS_FPU_EMU_INC_STATS(errors);
1082 *fault_addr = dva;
1083 return SIGSEGV;
1084 }
1085 break;
1086
1087 case lwc1_op:
1088 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1089 MIPSInst_SIMM(ir));
1090 MIPS_FPU_EMU_INC_STATS(loads);
1091 if (!access_ok(VERIFY_READ, wva, sizeof(u32))) {
1092 MIPS_FPU_EMU_INC_STATS(errors);
1093 *fault_addr = wva;
1094 return SIGBUS;
1095 }
1096 if (__get_user(wval, wva)) {
1097 MIPS_FPU_EMU_INC_STATS(errors);
1098 *fault_addr = wva;
1099 return SIGSEGV;
1100 }
1101 SITOREG(wval, MIPSInst_RT(ir));
1102 break;
1103
1104 case swc1_op:
1105 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1106 MIPSInst_SIMM(ir));
1107 MIPS_FPU_EMU_INC_STATS(stores);
1108 SIFROMREG(wval, MIPSInst_RT(ir));
1109 if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) {
1110 MIPS_FPU_EMU_INC_STATS(errors);
1111 *fault_addr = wva;
1112 return SIGBUS;
1113 }
1114 if (__put_user(wval, wva)) {
1115 MIPS_FPU_EMU_INC_STATS(errors);
1116 *fault_addr = wva;
1117 return SIGSEGV;
1118 }
1119 break;
1120
1121 case cop1_op:
1122 switch (MIPSInst_RS(ir)) {
1123 case dmfc_op:
1124 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1125 return SIGILL;
1126
1127 /* copregister fs -> gpr[rt] */
1128 if (MIPSInst_RT(ir) != 0) {
1129 DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1130 MIPSInst_RD(ir));
1131 }
1132 break;
1133
1134 case dmtc_op:
1135 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1136 return SIGILL;
1137
1138 /* copregister fs <- rt */
1139 DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1140 break;
1141
1142 case mfhc_op:
1143 if (!cpu_has_mips_r2_r6)
1144 goto sigill;
1145
1146 /* copregister rd -> gpr[rt] */
1147 if (MIPSInst_RT(ir) != 0) {
1148 SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
1149 MIPSInst_RD(ir));
1150 }
1151 break;
1152
1153 case mthc_op:
1154 if (!cpu_has_mips_r2_r6)
1155 goto sigill;
1156
1157 /* copregister rd <- gpr[rt] */
1158 SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1159 break;
1160
1161 case mfc_op:
1162 /* copregister rd -> gpr[rt] */
1163 if (MIPSInst_RT(ir) != 0) {
1164 SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1165 MIPSInst_RD(ir));
1166 }
1167 break;
1168
1169 case mtc_op:
1170 /* copregister rd <- rt */
1171 SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1172 break;
1173
1174 case cfc_op:
1175 /* cop control register rd -> gpr[rt] */
1176 cop1_cfc(xcp, ctx, ir);
1177 break;
1178
1179 case ctc_op:
1180 /* copregister rd <- rt */
1181 cop1_ctc(xcp, ctx, ir);
1182 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1183 return SIGFPE;
1184 }
1185 break;
1186
1187 case bc1eqz_op:
1188 case bc1nez_op:
1189 if (!cpu_has_mips_r6 || delay_slot(xcp))
1190 return SIGILL;
1191
1192 cond = likely = 0;
1193 fpr = &current->thread.fpu.fpr[MIPSInst_RT(ir)];
1194 bit0 = get_fpr32(fpr, 0) & 0x1;
1195 switch (MIPSInst_RS(ir)) {
1196 case bc1eqz_op:
1197 cond = bit0 == 0;
1198 break;
1199 case bc1nez_op:
1200 cond = bit0 != 0;
1201 break;
1202 }
1203 goto branch_common;
1204
1205 case bc_op:
1206 if (delay_slot(xcp))
1207 return SIGILL;
1208
1209 if (cpu_has_mips_4_5_r)
1210 cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
1211 else
1212 cbit = FPU_CSR_COND;
1213 cond = ctx->fcr31 & cbit;
1214
1215 likely = 0;
1216 switch (MIPSInst_RT(ir) & 3) {
1217 case bcfl_op:
1218 if (cpu_has_mips_2_3_4_5_r)
1219 likely = 1;
1220 /* Fall through */
1221 case bcf_op:
1222 cond = !cond;
1223 break;
1224 case bctl_op:
1225 if (cpu_has_mips_2_3_4_5_r)
1226 likely = 1;
1227 /* Fall through */
1228 case bct_op:
1229 break;
1230 }
1231 branch_common:
1232 set_delay_slot(xcp);
1233 if (cond) {
1234 /*
1235 * Branch taken: emulate dslot instruction
1236 */
1237 unsigned long bcpc;
1238
1239 /*
1240 * Remember EPC at the branch to point back
1241 * at so that any delay-slot instruction
1242 * signal is not silently ignored.
1243 */
1244 bcpc = xcp->cp0_epc;
1245 xcp->cp0_epc += dec_insn.pc_inc;
1246
1247 contpc = MIPSInst_SIMM(ir);
1248 ir = dec_insn.next_insn;
1249 if (dec_insn.micro_mips_mode) {
1250 contpc = (xcp->cp0_epc + (contpc << 1));
1251
1252 /* If 16-bit instruction, not FPU. */
1253 if ((dec_insn.next_pc_inc == 2) ||
1254 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
1255
1256 /*
1257 * Since this instruction will
1258 * be put on the stack with
1259 * 32-bit words, get around
1260 * this problem by putting a
1261 * NOP16 as the second one.
1262 */
1263 if (dec_insn.next_pc_inc == 2)
1264 ir = (ir & (~0xffff)) | MM_NOP16;
1265
1266 /*
1267 * Single step the non-CP1
1268 * instruction in the dslot.
1269 */
1270 sig = mips_dsemul(xcp, ir,
1271 contpc);
1272 if (sig < 0)
1273 break;
1274 if (sig)
1275 xcp->cp0_epc = bcpc;
1276 /*
1277 * SIGILL forces out of
1278 * the emulation loop.
1279 */
1280 return sig ? sig : SIGILL;
1281 }
1282 } else
1283 contpc = (xcp->cp0_epc + (contpc << 2));
1284
1285 switch (MIPSInst_OPCODE(ir)) {
1286 case lwc1_op:
1287 case swc1_op:
1288 goto emul;
1289
1290 case ldc1_op:
1291 case sdc1_op:
1292 if (cpu_has_mips_2_3_4_5_r)
1293 goto emul;
1294
1295 goto bc_sigill;
1296
1297 case cop1_op:
1298 goto emul;
1299
1300 case cop1x_op:
1301 if (cpu_has_mips_4_5_64_r2_r6)
1302 /* its one of ours */
1303 goto emul;
1304
1305 goto bc_sigill;
1306
1307 case spec_op:
1308 switch (MIPSInst_FUNC(ir)) {
1309 case movc_op:
1310 if (cpu_has_mips_4_5_r)
1311 goto emul;
1312
1313 goto bc_sigill;
1314 }
1315 break;
1316
1317 bc_sigill:
1318 xcp->cp0_epc = bcpc;
1319 return SIGILL;
1320 }
1321
1322 /*
1323 * Single step the non-cp1
1324 * instruction in the dslot
1325 */
1326 sig = mips_dsemul(xcp, ir, contpc);
1327 if (sig < 0)
1328 break;
1329 if (sig)
1330 xcp->cp0_epc = bcpc;
1331 /* SIGILL forces out of the emulation loop. */
1332 return sig ? sig : SIGILL;
1333 } else if (likely) { /* branch not taken */
1334 /*
1335 * branch likely nullifies
1336 * dslot if not taken
1337 */
1338 xcp->cp0_epc += dec_insn.pc_inc;
1339 contpc += dec_insn.pc_inc;
1340 /*
1341 * else continue & execute
1342 * dslot as normal insn
1343 */
1344 }
1345 break;
1346
1347 default:
1348 if (!(MIPSInst_RS(ir) & 0x10))
1349 return SIGILL;
1350
1351 /* a real fpu computation instruction */
1352 if ((sig = fpu_emu(xcp, ctx, ir)))
1353 return sig;
1354 }
1355 break;
1356
1357 case cop1x_op:
1358 if (!cpu_has_mips_4_5_64_r2_r6)
1359 return SIGILL;
1360
1361 sig = fpux_emu(xcp, ctx, ir, fault_addr);
1362 if (sig)
1363 return sig;
1364 break;
1365
1366 case spec_op:
1367 if (!cpu_has_mips_4_5_r)
1368 return SIGILL;
1369
1370 if (MIPSInst_FUNC(ir) != movc_op)
1371 return SIGILL;
1372 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
1373 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
1374 xcp->regs[MIPSInst_RD(ir)] =
1375 xcp->regs[MIPSInst_RS(ir)];
1376 break;
1377 default:
1378 sigill:
1379 return SIGILL;
1380 }
1381
1382 /* we did it !! */
1383 xcp->cp0_epc = contpc;
1384 clear_delay_slot(xcp);
1385
1386 return 0;
1387 }
1388
1389 /*
1390 * Conversion table from MIPS compare ops 48-63
1391 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
1392 */
1393 static const unsigned char cmptab[8] = {
1394 0, /* cmp_0 (sig) cmp_sf */
1395 IEEE754_CUN, /* cmp_un (sig) cmp_ngle */
1396 IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */
1397 IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */
1398 IEEE754_CLT, /* cmp_olt (sig) cmp_lt */
1399 IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */
1400 IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */
1401 IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */
1402 };
1403
1404 static const unsigned char negative_cmptab[8] = {
1405 0, /* Reserved */
1406 IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ,
1407 IEEE754_CLT | IEEE754_CGT | IEEE754_CUN,
1408 IEEE754_CLT | IEEE754_CGT,
1409 /* Reserved */
1410 };
1411
1412
1413 /*
1414 * Additional MIPS4 instructions
1415 */
1416
1417 #define DEF3OP(name, p, f1, f2, f3) \
1418 static union ieee754##p fpemu_##p##_##name(union ieee754##p r, \
1419 union ieee754##p s, union ieee754##p t) \
1420 { \
1421 struct _ieee754_csr ieee754_csr_save; \
1422 s = f1(s, t); \
1423 ieee754_csr_save = ieee754_csr; \
1424 s = f2(s, r); \
1425 ieee754_csr_save.cx |= ieee754_csr.cx; \
1426 ieee754_csr_save.sx |= ieee754_csr.sx; \
1427 s = f3(s); \
1428 ieee754_csr.cx |= ieee754_csr_save.cx; \
1429 ieee754_csr.sx |= ieee754_csr_save.sx; \
1430 return s; \
1431 }
1432
1433 static union ieee754dp fpemu_dp_recip(union ieee754dp d)
1434 {
1435 return ieee754dp_div(ieee754dp_one(0), d);
1436 }
1437
1438 static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
1439 {
1440 return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
1441 }
1442
1443 static union ieee754sp fpemu_sp_recip(union ieee754sp s)
1444 {
1445 return ieee754sp_div(ieee754sp_one(0), s);
1446 }
1447
1448 static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s)
1449 {
1450 return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
1451 }
1452
1453 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
1454 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
1455 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
1456 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
1457 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
1458 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
1459 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
1460 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
1461
1462 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1463 mips_instruction ir, void *__user *fault_addr)
1464 {
1465 unsigned rcsr = 0; /* resulting csr */
1466
1467 MIPS_FPU_EMU_INC_STATS(cp1xops);
1468
1469 switch (MIPSInst_FMA_FFMT(ir)) {
1470 case s_fmt:{ /* 0 */
1471
1472 union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
1473 union ieee754sp fd, fr, fs, ft;
1474 u32 __user *va;
1475 u32 val;
1476
1477 switch (MIPSInst_FUNC(ir)) {
1478 case lwxc1_op:
1479 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1480 xcp->regs[MIPSInst_FT(ir)]);
1481
1482 MIPS_FPU_EMU_INC_STATS(loads);
1483 if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
1484 MIPS_FPU_EMU_INC_STATS(errors);
1485 *fault_addr = va;
1486 return SIGBUS;
1487 }
1488 if (__get_user(val, va)) {
1489 MIPS_FPU_EMU_INC_STATS(errors);
1490 *fault_addr = va;
1491 return SIGSEGV;
1492 }
1493 SITOREG(val, MIPSInst_FD(ir));
1494 break;
1495
1496 case swxc1_op:
1497 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1498 xcp->regs[MIPSInst_FT(ir)]);
1499
1500 MIPS_FPU_EMU_INC_STATS(stores);
1501
1502 SIFROMREG(val, MIPSInst_FS(ir));
1503 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
1504 MIPS_FPU_EMU_INC_STATS(errors);
1505 *fault_addr = va;
1506 return SIGBUS;
1507 }
1508 if (put_user(val, va)) {
1509 MIPS_FPU_EMU_INC_STATS(errors);
1510 *fault_addr = va;
1511 return SIGSEGV;
1512 }
1513 break;
1514
1515 case madd_s_op:
1516 handler = fpemu_sp_madd;
1517 goto scoptop;
1518 case msub_s_op:
1519 handler = fpemu_sp_msub;
1520 goto scoptop;
1521 case nmadd_s_op:
1522 handler = fpemu_sp_nmadd;
1523 goto scoptop;
1524 case nmsub_s_op:
1525 handler = fpemu_sp_nmsub;
1526 goto scoptop;
1527
1528 scoptop:
1529 SPFROMREG(fr, MIPSInst_FR(ir));
1530 SPFROMREG(fs, MIPSInst_FS(ir));
1531 SPFROMREG(ft, MIPSInst_FT(ir));
1532 fd = (*handler) (fr, fs, ft);
1533 SPTOREG(fd, MIPSInst_FD(ir));
1534
1535 copcsr:
1536 if (ieee754_cxtest(IEEE754_INEXACT)) {
1537 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1538 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1539 }
1540 if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1541 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1542 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1543 }
1544 if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1545 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1546 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1547 }
1548 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1549 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1550 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1551 }
1552
1553 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1554 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1555 /*printk ("SIGFPE: FPU csr = %08x\n",
1556 ctx->fcr31); */
1557 return SIGFPE;
1558 }
1559
1560 break;
1561
1562 default:
1563 return SIGILL;
1564 }
1565 break;
1566 }
1567
1568 case d_fmt:{ /* 1 */
1569 union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
1570 union ieee754dp fd, fr, fs, ft;
1571 u64 __user *va;
1572 u64 val;
1573
1574 switch (MIPSInst_FUNC(ir)) {
1575 case ldxc1_op:
1576 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1577 xcp->regs[MIPSInst_FT(ir)]);
1578
1579 MIPS_FPU_EMU_INC_STATS(loads);
1580 if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
1581 MIPS_FPU_EMU_INC_STATS(errors);
1582 *fault_addr = va;
1583 return SIGBUS;
1584 }
1585 if (__get_user(val, va)) {
1586 MIPS_FPU_EMU_INC_STATS(errors);
1587 *fault_addr = va;
1588 return SIGSEGV;
1589 }
1590 DITOREG(val, MIPSInst_FD(ir));
1591 break;
1592
1593 case sdxc1_op:
1594 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1595 xcp->regs[MIPSInst_FT(ir)]);
1596
1597 MIPS_FPU_EMU_INC_STATS(stores);
1598 DIFROMREG(val, MIPSInst_FS(ir));
1599 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
1600 MIPS_FPU_EMU_INC_STATS(errors);
1601 *fault_addr = va;
1602 return SIGBUS;
1603 }
1604 if (__put_user(val, va)) {
1605 MIPS_FPU_EMU_INC_STATS(errors);
1606 *fault_addr = va;
1607 return SIGSEGV;
1608 }
1609 break;
1610
1611 case madd_d_op:
1612 handler = fpemu_dp_madd;
1613 goto dcoptop;
1614 case msub_d_op:
1615 handler = fpemu_dp_msub;
1616 goto dcoptop;
1617 case nmadd_d_op:
1618 handler = fpemu_dp_nmadd;
1619 goto dcoptop;
1620 case nmsub_d_op:
1621 handler = fpemu_dp_nmsub;
1622 goto dcoptop;
1623
1624 dcoptop:
1625 DPFROMREG(fr, MIPSInst_FR(ir));
1626 DPFROMREG(fs, MIPSInst_FS(ir));
1627 DPFROMREG(ft, MIPSInst_FT(ir));
1628 fd = (*handler) (fr, fs, ft);
1629 DPTOREG(fd, MIPSInst_FD(ir));
1630 goto copcsr;
1631
1632 default:
1633 return SIGILL;
1634 }
1635 break;
1636 }
1637
1638 case 0x3:
1639 if (MIPSInst_FUNC(ir) != pfetch_op)
1640 return SIGILL;
1641
1642 /* ignore prefx operation */
1643 break;
1644
1645 default:
1646 return SIGILL;
1647 }
1648
1649 return 0;
1650 }
1651
1652
1653
1654 /*
1655 * Emulate a single COP1 arithmetic instruction.
1656 */
1657 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1658 mips_instruction ir)
1659 {
1660 int rfmt; /* resulting format */
1661 unsigned rcsr = 0; /* resulting csr */
1662 unsigned int oldrm;
1663 unsigned int cbit;
1664 unsigned cond;
1665 union {
1666 union ieee754dp d;
1667 union ieee754sp s;
1668 int w;
1669 s64 l;
1670 } rv; /* resulting value */
1671 u64 bits;
1672
1673 MIPS_FPU_EMU_INC_STATS(cp1ops);
1674 switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
1675 case s_fmt: { /* 0 */
1676 union {
1677 union ieee754sp(*b) (union ieee754sp, union ieee754sp);
1678 union ieee754sp(*u) (union ieee754sp);
1679 } handler;
1680 union ieee754sp fd, fs, ft;
1681
1682 switch (MIPSInst_FUNC(ir)) {
1683 /* binary ops */
1684 case fadd_op:
1685 handler.b = ieee754sp_add;
1686 goto scopbop;
1687 case fsub_op:
1688 handler.b = ieee754sp_sub;
1689 goto scopbop;
1690 case fmul_op:
1691 handler.b = ieee754sp_mul;
1692 goto scopbop;
1693 case fdiv_op:
1694 handler.b = ieee754sp_div;
1695 goto scopbop;
1696
1697 /* unary ops */
1698 case fsqrt_op:
1699 if (!cpu_has_mips_2_3_4_5_r)
1700 return SIGILL;
1701
1702 handler.u = ieee754sp_sqrt;
1703 goto scopuop;
1704
1705 /*
1706 * Note that on some MIPS IV implementations such as the
1707 * R5000 and R8000 the FSQRT and FRECIP instructions do not
1708 * achieve full IEEE-754 accuracy - however this emulator does.
1709 */
1710 case frsqrt_op:
1711 if (!cpu_has_mips_4_5_64_r2_r6)
1712 return SIGILL;
1713
1714 handler.u = fpemu_sp_rsqrt;
1715 goto scopuop;
1716
1717 case frecip_op:
1718 if (!cpu_has_mips_4_5_64_r2_r6)
1719 return SIGILL;
1720
1721 handler.u = fpemu_sp_recip;
1722 goto scopuop;
1723
1724 case fmovc_op:
1725 if (!cpu_has_mips_4_5_r)
1726 return SIGILL;
1727
1728 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1729 if (((ctx->fcr31 & cond) != 0) !=
1730 ((MIPSInst_FT(ir) & 1) != 0))
1731 return 0;
1732 SPFROMREG(rv.s, MIPSInst_FS(ir));
1733 break;
1734
1735 case fmovz_op:
1736 if (!cpu_has_mips_4_5_r)
1737 return SIGILL;
1738
1739 if (xcp->regs[MIPSInst_FT(ir)] != 0)
1740 return 0;
1741 SPFROMREG(rv.s, MIPSInst_FS(ir));
1742 break;
1743
1744 case fmovn_op:
1745 if (!cpu_has_mips_4_5_r)
1746 return SIGILL;
1747
1748 if (xcp->regs[MIPSInst_FT(ir)] == 0)
1749 return 0;
1750 SPFROMREG(rv.s, MIPSInst_FS(ir));
1751 break;
1752
1753 case fseleqz_op:
1754 if (!cpu_has_mips_r6)
1755 return SIGILL;
1756
1757 SPFROMREG(rv.s, MIPSInst_FT(ir));
1758 if (rv.w & 0x1)
1759 rv.w = 0;
1760 else
1761 SPFROMREG(rv.s, MIPSInst_FS(ir));
1762 break;
1763
1764 case fselnez_op:
1765 if (!cpu_has_mips_r6)
1766 return SIGILL;
1767
1768 SPFROMREG(rv.s, MIPSInst_FT(ir));
1769 if (rv.w & 0x1)
1770 SPFROMREG(rv.s, MIPSInst_FS(ir));
1771 else
1772 rv.w = 0;
1773 break;
1774
1775 case fmaddf_op: {
1776 union ieee754sp ft, fs, fd;
1777
1778 if (!cpu_has_mips_r6)
1779 return SIGILL;
1780
1781 SPFROMREG(ft, MIPSInst_FT(ir));
1782 SPFROMREG(fs, MIPSInst_FS(ir));
1783 SPFROMREG(fd, MIPSInst_FD(ir));
1784 rv.s = ieee754sp_maddf(fd, fs, ft);
1785 break;
1786 }
1787
1788 case fmsubf_op: {
1789 union ieee754sp ft, fs, fd;
1790
1791 if (!cpu_has_mips_r6)
1792 return SIGILL;
1793
1794 SPFROMREG(ft, MIPSInst_FT(ir));
1795 SPFROMREG(fs, MIPSInst_FS(ir));
1796 SPFROMREG(fd, MIPSInst_FD(ir));
1797 rv.s = ieee754sp_msubf(fd, fs, ft);
1798 break;
1799 }
1800
1801 case frint_op: {
1802 union ieee754sp fs;
1803
1804 if (!cpu_has_mips_r6)
1805 return SIGILL;
1806
1807 SPFROMREG(fs, MIPSInst_FS(ir));
1808 rv.l = ieee754sp_tlong(fs);
1809 rv.s = ieee754sp_flong(rv.l);
1810 goto copcsr;
1811 }
1812
1813 case fclass_op: {
1814 union ieee754sp fs;
1815
1816 if (!cpu_has_mips_r6)
1817 return SIGILL;
1818
1819 SPFROMREG(fs, MIPSInst_FS(ir));
1820 rv.w = ieee754sp_2008class(fs);
1821 rfmt = w_fmt;
1822 break;
1823 }
1824
1825 case fmin_op: {
1826 union ieee754sp fs, ft;
1827
1828 if (!cpu_has_mips_r6)
1829 return SIGILL;
1830
1831 SPFROMREG(ft, MIPSInst_FT(ir));
1832 SPFROMREG(fs, MIPSInst_FS(ir));
1833 rv.s = ieee754sp_fmin(fs, ft);
1834 break;
1835 }
1836
1837 case fmina_op: {
1838 union ieee754sp fs, ft;
1839
1840 if (!cpu_has_mips_r6)
1841 return SIGILL;
1842
1843 SPFROMREG(ft, MIPSInst_FT(ir));
1844 SPFROMREG(fs, MIPSInst_FS(ir));
1845 rv.s = ieee754sp_fmina(fs, ft);
1846 break;
1847 }
1848
1849 case fmax_op: {
1850 union ieee754sp fs, ft;
1851
1852 if (!cpu_has_mips_r6)
1853 return SIGILL;
1854
1855 SPFROMREG(ft, MIPSInst_FT(ir));
1856 SPFROMREG(fs, MIPSInst_FS(ir));
1857 rv.s = ieee754sp_fmax(fs, ft);
1858 break;
1859 }
1860
1861 case fmaxa_op: {
1862 union ieee754sp fs, ft;
1863
1864 if (!cpu_has_mips_r6)
1865 return SIGILL;
1866
1867 SPFROMREG(ft, MIPSInst_FT(ir));
1868 SPFROMREG(fs, MIPSInst_FS(ir));
1869 rv.s = ieee754sp_fmaxa(fs, ft);
1870 break;
1871 }
1872
1873 case fabs_op:
1874 handler.u = ieee754sp_abs;
1875 goto scopuop;
1876
1877 case fneg_op:
1878 handler.u = ieee754sp_neg;
1879 goto scopuop;
1880
1881 case fmov_op:
1882 /* an easy one */
1883 SPFROMREG(rv.s, MIPSInst_FS(ir));
1884 goto copcsr;
1885
1886 /* binary op on handler */
1887 scopbop:
1888 SPFROMREG(fs, MIPSInst_FS(ir));
1889 SPFROMREG(ft, MIPSInst_FT(ir));
1890
1891 rv.s = (*handler.b) (fs, ft);
1892 goto copcsr;
1893 scopuop:
1894 SPFROMREG(fs, MIPSInst_FS(ir));
1895 rv.s = (*handler.u) (fs);
1896 goto copcsr;
1897 copcsr:
1898 if (ieee754_cxtest(IEEE754_INEXACT)) {
1899 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1900 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1901 }
1902 if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1903 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1904 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1905 }
1906 if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1907 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1908 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1909 }
1910 if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) {
1911 MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv);
1912 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
1913 }
1914 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1915 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1916 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1917 }
1918 break;
1919
1920 /* unary conv ops */
1921 case fcvts_op:
1922 return SIGILL; /* not defined */
1923
1924 case fcvtd_op:
1925 SPFROMREG(fs, MIPSInst_FS(ir));
1926 rv.d = ieee754dp_fsp(fs);
1927 rfmt = d_fmt;
1928 goto copcsr;
1929
1930 case fcvtw_op:
1931 SPFROMREG(fs, MIPSInst_FS(ir));
1932 rv.w = ieee754sp_tint(fs);
1933 rfmt = w_fmt;
1934 goto copcsr;
1935
1936 case fround_op:
1937 case ftrunc_op:
1938 case fceil_op:
1939 case ffloor_op:
1940 if (!cpu_has_mips_2_3_4_5_r)
1941 return SIGILL;
1942
1943 oldrm = ieee754_csr.rm;
1944 SPFROMREG(fs, MIPSInst_FS(ir));
1945 ieee754_csr.rm = MIPSInst_FUNC(ir);
1946 rv.w = ieee754sp_tint(fs);
1947 ieee754_csr.rm = oldrm;
1948 rfmt = w_fmt;
1949 goto copcsr;
1950
1951 case fsel_op:
1952 if (!cpu_has_mips_r6)
1953 return SIGILL;
1954
1955 SPFROMREG(fd, MIPSInst_FD(ir));
1956 if (fd.bits & 0x1)
1957 SPFROMREG(rv.s, MIPSInst_FT(ir));
1958 else
1959 SPFROMREG(rv.s, MIPSInst_FS(ir));
1960 break;
1961
1962 case fcvtl_op:
1963 if (!cpu_has_mips_3_4_5_64_r2_r6)
1964 return SIGILL;
1965
1966 SPFROMREG(fs, MIPSInst_FS(ir));
1967 rv.l = ieee754sp_tlong(fs);
1968 rfmt = l_fmt;
1969 goto copcsr;
1970
1971 case froundl_op:
1972 case ftruncl_op:
1973 case fceill_op:
1974 case ffloorl_op:
1975 if (!cpu_has_mips_3_4_5_64_r2_r6)
1976 return SIGILL;
1977
1978 oldrm = ieee754_csr.rm;
1979 SPFROMREG(fs, MIPSInst_FS(ir));
1980 ieee754_csr.rm = MIPSInst_FUNC(ir);
1981 rv.l = ieee754sp_tlong(fs);
1982 ieee754_csr.rm = oldrm;
1983 rfmt = l_fmt;
1984 goto copcsr;
1985
1986 default:
1987 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
1988 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1989 union ieee754sp fs, ft;
1990
1991 SPFROMREG(fs, MIPSInst_FS(ir));
1992 SPFROMREG(ft, MIPSInst_FT(ir));
1993 rv.w = ieee754sp_cmp(fs, ft,
1994 cmptab[cmpop & 0x7], cmpop & 0x8);
1995 rfmt = -1;
1996 if ((cmpop & 0x8) && ieee754_cxtest
1997 (IEEE754_INVALID_OPERATION))
1998 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1999 else
2000 goto copcsr;
2001
2002 } else
2003 return SIGILL;
2004 break;
2005 }
2006 break;
2007 }
2008
2009 case d_fmt: {
2010 union ieee754dp fd, fs, ft;
2011 union {
2012 union ieee754dp(*b) (union ieee754dp, union ieee754dp);
2013 union ieee754dp(*u) (union ieee754dp);
2014 } handler;
2015
2016 switch (MIPSInst_FUNC(ir)) {
2017 /* binary ops */
2018 case fadd_op:
2019 handler.b = ieee754dp_add;
2020 goto dcopbop;
2021 case fsub_op:
2022 handler.b = ieee754dp_sub;
2023 goto dcopbop;
2024 case fmul_op:
2025 handler.b = ieee754dp_mul;
2026 goto dcopbop;
2027 case fdiv_op:
2028 handler.b = ieee754dp_div;
2029 goto dcopbop;
2030
2031 /* unary ops */
2032 case fsqrt_op:
2033 if (!cpu_has_mips_2_3_4_5_r)
2034 return SIGILL;
2035
2036 handler.u = ieee754dp_sqrt;
2037 goto dcopuop;
2038 /*
2039 * Note that on some MIPS IV implementations such as the
2040 * R5000 and R8000 the FSQRT and FRECIP instructions do not
2041 * achieve full IEEE-754 accuracy - however this emulator does.
2042 */
2043 case frsqrt_op:
2044 if (!cpu_has_mips_4_5_64_r2_r6)
2045 return SIGILL;
2046
2047 handler.u = fpemu_dp_rsqrt;
2048 goto dcopuop;
2049 case frecip_op:
2050 if (!cpu_has_mips_4_5_64_r2_r6)
2051 return SIGILL;
2052
2053 handler.u = fpemu_dp_recip;
2054 goto dcopuop;
2055 case fmovc_op:
2056 if (!cpu_has_mips_4_5_r)
2057 return SIGILL;
2058
2059 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
2060 if (((ctx->fcr31 & cond) != 0) !=
2061 ((MIPSInst_FT(ir) & 1) != 0))
2062 return 0;
2063 DPFROMREG(rv.d, MIPSInst_FS(ir));
2064 break;
2065 case fmovz_op:
2066 if (!cpu_has_mips_4_5_r)
2067 return SIGILL;
2068
2069 if (xcp->regs[MIPSInst_FT(ir)] != 0)
2070 return 0;
2071 DPFROMREG(rv.d, MIPSInst_FS(ir));
2072 break;
2073 case fmovn_op:
2074 if (!cpu_has_mips_4_5_r)
2075 return SIGILL;
2076
2077 if (xcp->regs[MIPSInst_FT(ir)] == 0)
2078 return 0;
2079 DPFROMREG(rv.d, MIPSInst_FS(ir));
2080 break;
2081
2082 case fseleqz_op:
2083 if (!cpu_has_mips_r6)
2084 return SIGILL;
2085
2086 DPFROMREG(rv.d, MIPSInst_FT(ir));
2087 if (rv.l & 0x1)
2088 rv.l = 0;
2089 else
2090 DPFROMREG(rv.d, MIPSInst_FS(ir));
2091 break;
2092
2093 case fselnez_op:
2094 if (!cpu_has_mips_r6)
2095 return SIGILL;
2096
2097 DPFROMREG(rv.d, MIPSInst_FT(ir));
2098 if (rv.l & 0x1)
2099 DPFROMREG(rv.d, MIPSInst_FS(ir));
2100 else
2101 rv.l = 0;
2102 break;
2103
2104 case fmaddf_op: {
2105 union ieee754dp ft, fs, fd;
2106
2107 if (!cpu_has_mips_r6)
2108 return SIGILL;
2109
2110 DPFROMREG(ft, MIPSInst_FT(ir));
2111 DPFROMREG(fs, MIPSInst_FS(ir));
2112 DPFROMREG(fd, MIPSInst_FD(ir));
2113 rv.d = ieee754dp_maddf(fd, fs, ft);
2114 break;
2115 }
2116
2117 case fmsubf_op: {
2118 union ieee754dp ft, fs, fd;
2119
2120 if (!cpu_has_mips_r6)
2121 return SIGILL;
2122
2123 DPFROMREG(ft, MIPSInst_FT(ir));
2124 DPFROMREG(fs, MIPSInst_FS(ir));
2125 DPFROMREG(fd, MIPSInst_FD(ir));
2126 rv.d = ieee754dp_msubf(fd, fs, ft);
2127 break;
2128 }
2129
2130 case frint_op: {
2131 union ieee754dp fs;
2132
2133 if (!cpu_has_mips_r6)
2134 return SIGILL;
2135
2136 DPFROMREG(fs, MIPSInst_FS(ir));
2137 rv.l = ieee754dp_tlong(fs);
2138 rv.d = ieee754dp_flong(rv.l);
2139 goto copcsr;
2140 }
2141
2142 case fclass_op: {
2143 union ieee754dp fs;
2144
2145 if (!cpu_has_mips_r6)
2146 return SIGILL;
2147
2148 DPFROMREG(fs, MIPSInst_FS(ir));
2149 rv.w = ieee754dp_2008class(fs);
2150 rfmt = w_fmt;
2151 break;
2152 }
2153
2154 case fmin_op: {
2155 union ieee754dp fs, ft;
2156
2157 if (!cpu_has_mips_r6)
2158 return SIGILL;
2159
2160 DPFROMREG(ft, MIPSInst_FT(ir));
2161 DPFROMREG(fs, MIPSInst_FS(ir));
2162 rv.d = ieee754dp_fmin(fs, ft);
2163 break;
2164 }
2165
2166 case fmina_op: {
2167 union ieee754dp fs, ft;
2168
2169 if (!cpu_has_mips_r6)
2170 return SIGILL;
2171
2172 DPFROMREG(ft, MIPSInst_FT(ir));
2173 DPFROMREG(fs, MIPSInst_FS(ir));
2174 rv.d = ieee754dp_fmina(fs, ft);
2175 break;
2176 }
2177
2178 case fmax_op: {
2179 union ieee754dp fs, ft;
2180
2181 if (!cpu_has_mips_r6)
2182 return SIGILL;
2183
2184 DPFROMREG(ft, MIPSInst_FT(ir));
2185 DPFROMREG(fs, MIPSInst_FS(ir));
2186 rv.d = ieee754dp_fmax(fs, ft);
2187 break;
2188 }
2189
2190 case fmaxa_op: {
2191 union ieee754dp fs, ft;
2192
2193 if (!cpu_has_mips_r6)
2194 return SIGILL;
2195
2196 DPFROMREG(ft, MIPSInst_FT(ir));
2197 DPFROMREG(fs, MIPSInst_FS(ir));
2198 rv.d = ieee754dp_fmaxa(fs, ft);
2199 break;
2200 }
2201
2202 case fabs_op:
2203 handler.u = ieee754dp_abs;
2204 goto dcopuop;
2205
2206 case fneg_op:
2207 handler.u = ieee754dp_neg;
2208 goto dcopuop;
2209
2210 case fmov_op:
2211 /* an easy one */
2212 DPFROMREG(rv.d, MIPSInst_FS(ir));
2213 goto copcsr;
2214
2215 /* binary op on handler */
2216 dcopbop:
2217 DPFROMREG(fs, MIPSInst_FS(ir));
2218 DPFROMREG(ft, MIPSInst_FT(ir));
2219
2220 rv.d = (*handler.b) (fs, ft);
2221 goto copcsr;
2222 dcopuop:
2223 DPFROMREG(fs, MIPSInst_FS(ir));
2224 rv.d = (*handler.u) (fs);
2225 goto copcsr;
2226
2227 /*
2228 * unary conv ops
2229 */
2230 case fcvts_op:
2231 DPFROMREG(fs, MIPSInst_FS(ir));
2232 rv.s = ieee754sp_fdp(fs);
2233 rfmt = s_fmt;
2234 goto copcsr;
2235
2236 case fcvtd_op:
2237 return SIGILL; /* not defined */
2238
2239 case fcvtw_op:
2240 DPFROMREG(fs, MIPSInst_FS(ir));
2241 rv.w = ieee754dp_tint(fs); /* wrong */
2242 rfmt = w_fmt;
2243 goto copcsr;
2244
2245 case fround_op:
2246 case ftrunc_op:
2247 case fceil_op:
2248 case ffloor_op:
2249 if (!cpu_has_mips_2_3_4_5_r)
2250 return SIGILL;
2251
2252 oldrm = ieee754_csr.rm;
2253 DPFROMREG(fs, MIPSInst_FS(ir));
2254 ieee754_csr.rm = MIPSInst_FUNC(ir);
2255 rv.w = ieee754dp_tint(fs);
2256 ieee754_csr.rm = oldrm;
2257 rfmt = w_fmt;
2258 goto copcsr;
2259
2260 case fsel_op:
2261 if (!cpu_has_mips_r6)
2262 return SIGILL;
2263
2264 DPFROMREG(fd, MIPSInst_FD(ir));
2265 if (fd.bits & 0x1)
2266 DPFROMREG(rv.d, MIPSInst_FT(ir));
2267 else
2268 DPFROMREG(rv.d, MIPSInst_FS(ir));
2269 break;
2270
2271 case fcvtl_op:
2272 if (!cpu_has_mips_3_4_5_64_r2_r6)
2273 return SIGILL;
2274
2275 DPFROMREG(fs, MIPSInst_FS(ir));
2276 rv.l = ieee754dp_tlong(fs);
2277 rfmt = l_fmt;
2278 goto copcsr;
2279
2280 case froundl_op:
2281 case ftruncl_op:
2282 case fceill_op:
2283 case ffloorl_op:
2284 if (!cpu_has_mips_3_4_5_64_r2_r6)
2285 return SIGILL;
2286
2287 oldrm = ieee754_csr.rm;
2288 DPFROMREG(fs, MIPSInst_FS(ir));
2289 ieee754_csr.rm = MIPSInst_FUNC(ir);
2290 rv.l = ieee754dp_tlong(fs);
2291 ieee754_csr.rm = oldrm;
2292 rfmt = l_fmt;
2293 goto copcsr;
2294
2295 default:
2296 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2297 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2298 union ieee754dp fs, ft;
2299
2300 DPFROMREG(fs, MIPSInst_FS(ir));
2301 DPFROMREG(ft, MIPSInst_FT(ir));
2302 rv.w = ieee754dp_cmp(fs, ft,
2303 cmptab[cmpop & 0x7], cmpop & 0x8);
2304 rfmt = -1;
2305 if ((cmpop & 0x8)
2306 &&
2307 ieee754_cxtest
2308 (IEEE754_INVALID_OPERATION))
2309 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2310 else
2311 goto copcsr;
2312
2313 }
2314 else {
2315 return SIGILL;
2316 }
2317 break;
2318 }
2319 break;
2320 }
2321
2322 case w_fmt: {
2323 union ieee754dp fs;
2324
2325 switch (MIPSInst_FUNC(ir)) {
2326 case fcvts_op:
2327 /* convert word to single precision real */
2328 SPFROMREG(fs, MIPSInst_FS(ir));
2329 rv.s = ieee754sp_fint(fs.bits);
2330 rfmt = s_fmt;
2331 goto copcsr;
2332 case fcvtd_op:
2333 /* convert word to double precision real */
2334 SPFROMREG(fs, MIPSInst_FS(ir));
2335 rv.d = ieee754dp_fint(fs.bits);
2336 rfmt = d_fmt;
2337 goto copcsr;
2338 default: {
2339 /* Emulating the new CMP.condn.fmt R6 instruction */
2340 #define CMPOP_MASK 0x7
2341 #define SIGN_BIT (0x1 << 3)
2342 #define PREDICATE_BIT (0x1 << 4)
2343
2344 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2345 int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2346 union ieee754sp fs, ft;
2347
2348 /* This is an R6 only instruction */
2349 if (!cpu_has_mips_r6 ||
2350 (MIPSInst_FUNC(ir) & 0x20))
2351 return SIGILL;
2352
2353 /* fmt is w_fmt for single precision so fix it */
2354 rfmt = s_fmt;
2355 /* default to false */
2356 rv.w = 0;
2357
2358 /* CMP.condn.S */
2359 SPFROMREG(fs, MIPSInst_FS(ir));
2360 SPFROMREG(ft, MIPSInst_FT(ir));
2361
2362 /* positive predicates */
2363 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2364 if (ieee754sp_cmp(fs, ft, cmptab[cmpop],
2365 sig))
2366 rv.w = -1; /* true, all 1s */
2367 if ((sig) &&
2368 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2369 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2370 else
2371 goto copcsr;
2372 } else {
2373 /* negative predicates */
2374 switch (cmpop) {
2375 case 1:
2376 case 2:
2377 case 3:
2378 if (ieee754sp_cmp(fs, ft,
2379 negative_cmptab[cmpop],
2380 sig))
2381 rv.w = -1; /* true, all 1s */
2382 if (sig &&
2383 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2384 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2385 else
2386 goto copcsr;
2387 break;
2388 default:
2389 /* Reserved R6 ops */
2390 pr_err("Reserved MIPS R6 CMP.condn.S operation\n");
2391 return SIGILL;
2392 }
2393 }
2394 break;
2395 }
2396 }
2397 }
2398
2399 case l_fmt:
2400
2401 if (!cpu_has_mips_3_4_5_64_r2_r6)
2402 return SIGILL;
2403
2404 DIFROMREG(bits, MIPSInst_FS(ir));
2405
2406 switch (MIPSInst_FUNC(ir)) {
2407 case fcvts_op:
2408 /* convert long to single precision real */
2409 rv.s = ieee754sp_flong(bits);
2410 rfmt = s_fmt;
2411 goto copcsr;
2412 case fcvtd_op:
2413 /* convert long to double precision real */
2414 rv.d = ieee754dp_flong(bits);
2415 rfmt = d_fmt;
2416 goto copcsr;
2417 default: {
2418 /* Emulating the new CMP.condn.fmt R6 instruction */
2419 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2420 int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2421 union ieee754dp fs, ft;
2422
2423 if (!cpu_has_mips_r6 ||
2424 (MIPSInst_FUNC(ir) & 0x20))
2425 return SIGILL;
2426
2427 /* fmt is l_fmt for double precision so fix it */
2428 rfmt = d_fmt;
2429 /* default to false */
2430 rv.l = 0;
2431
2432 /* CMP.condn.D */
2433 DPFROMREG(fs, MIPSInst_FS(ir));
2434 DPFROMREG(ft, MIPSInst_FT(ir));
2435
2436 /* positive predicates */
2437 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2438 if (ieee754dp_cmp(fs, ft,
2439 cmptab[cmpop], sig))
2440 rv.l = -1LL; /* true, all 1s */
2441 if (sig &&
2442 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2443 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2444 else
2445 goto copcsr;
2446 } else {
2447 /* negative predicates */
2448 switch (cmpop) {
2449 case 1:
2450 case 2:
2451 case 3:
2452 if (ieee754dp_cmp(fs, ft,
2453 negative_cmptab[cmpop],
2454 sig))
2455 rv.l = -1LL; /* true, all 1s */
2456 if (sig &&
2457 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2458 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2459 else
2460 goto copcsr;
2461 break;
2462 default:
2463 /* Reserved R6 ops */
2464 pr_err("Reserved MIPS R6 CMP.condn.D operation\n");
2465 return SIGILL;
2466 }
2467 }
2468 break;
2469 }
2470 }
2471 default:
2472 return SIGILL;
2473 }
2474
2475 /*
2476 * Update the fpu CSR register for this operation.
2477 * If an exception is required, generate a tidy SIGFPE exception,
2478 * without updating the result register.
2479 * Note: cause exception bits do not accumulate, they are rewritten
2480 * for each op; only the flag/sticky bits accumulate.
2481 */
2482 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
2483 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
2484 /*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */
2485 return SIGFPE;
2486 }
2487
2488 /*
2489 * Now we can safely write the result back to the register file.
2490 */
2491 switch (rfmt) {
2492 case -1:
2493
2494 if (cpu_has_mips_4_5_r)
2495 cbit = fpucondbit[MIPSInst_FD(ir) >> 2];
2496 else
2497 cbit = FPU_CSR_COND;
2498 if (rv.w)
2499 ctx->fcr31 |= cbit;
2500 else
2501 ctx->fcr31 &= ~cbit;
2502 break;
2503
2504 case d_fmt:
2505 DPTOREG(rv.d, MIPSInst_FD(ir));
2506 break;
2507 case s_fmt:
2508 SPTOREG(rv.s, MIPSInst_FD(ir));
2509 break;
2510 case w_fmt:
2511 SITOREG(rv.w, MIPSInst_FD(ir));
2512 break;
2513 case l_fmt:
2514 if (!cpu_has_mips_3_4_5_64_r2_r6)
2515 return SIGILL;
2516
2517 DITOREG(rv.l, MIPSInst_FD(ir));
2518 break;
2519 default:
2520 return SIGILL;
2521 }
2522
2523 return 0;
2524 }
2525
2526 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
2527 int has_fpu, void *__user *fault_addr)
2528 {
2529 unsigned long oldepc, prevepc;
2530 struct mm_decoded_insn dec_insn;
2531 u16 instr[4];
2532 u16 *instr_ptr;
2533 int sig = 0;
2534
2535 oldepc = xcp->cp0_epc;
2536 do {
2537 prevepc = xcp->cp0_epc;
2538
2539 if (get_isa16_mode(prevepc) && cpu_has_mmips) {
2540 /*
2541 * Get next 2 microMIPS instructions and convert them
2542 * into 32-bit instructions.
2543 */
2544 if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
2545 (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
2546 (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
2547 (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
2548 MIPS_FPU_EMU_INC_STATS(errors);
2549 return SIGBUS;
2550 }
2551 instr_ptr = instr;
2552
2553 /* Get first instruction. */
2554 if (mm_insn_16bit(*instr_ptr)) {
2555 /* Duplicate the half-word. */
2556 dec_insn.insn = (*instr_ptr << 16) |
2557 (*instr_ptr);
2558 /* 16-bit instruction. */
2559 dec_insn.pc_inc = 2;
2560 instr_ptr += 1;
2561 } else {
2562 dec_insn.insn = (*instr_ptr << 16) |
2563 *(instr_ptr+1);
2564 /* 32-bit instruction. */
2565 dec_insn.pc_inc = 4;
2566 instr_ptr += 2;
2567 }
2568 /* Get second instruction. */
2569 if (mm_insn_16bit(*instr_ptr)) {
2570 /* Duplicate the half-word. */
2571 dec_insn.next_insn = (*instr_ptr << 16) |
2572 (*instr_ptr);
2573 /* 16-bit instruction. */
2574 dec_insn.next_pc_inc = 2;
2575 } else {
2576 dec_insn.next_insn = (*instr_ptr << 16) |
2577 *(instr_ptr+1);
2578 /* 32-bit instruction. */
2579 dec_insn.next_pc_inc = 4;
2580 }
2581 dec_insn.micro_mips_mode = 1;
2582 } else {
2583 if ((get_user(dec_insn.insn,
2584 (mips_instruction __user *) xcp->cp0_epc)) ||
2585 (get_user(dec_insn.next_insn,
2586 (mips_instruction __user *)(xcp->cp0_epc+4)))) {
2587 MIPS_FPU_EMU_INC_STATS(errors);
2588 return SIGBUS;
2589 }
2590 dec_insn.pc_inc = 4;
2591 dec_insn.next_pc_inc = 4;
2592 dec_insn.micro_mips_mode = 0;
2593 }
2594
2595 if ((dec_insn.insn == 0) ||
2596 ((dec_insn.pc_inc == 2) &&
2597 ((dec_insn.insn & 0xffff) == MM_NOP16)))
2598 xcp->cp0_epc += dec_insn.pc_inc; /* Skip NOPs */
2599 else {
2600 /*
2601 * The 'ieee754_csr' is an alias of ctx->fcr31.
2602 * No need to copy ctx->fcr31 to ieee754_csr.
2603 */
2604 sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
2605 }
2606
2607 if (has_fpu)
2608 break;
2609 if (sig)
2610 break;
2611
2612 cond_resched();
2613 } while (xcp->cp0_epc > prevepc);
2614
2615 /* SIGILL indicates a non-fpu instruction */
2616 if (sig == SIGILL && xcp->cp0_epc != oldepc)
2617 /* but if EPC has advanced, then ignore it */
2618 sig = 0;
2619
2620 return sig;
2621 }
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