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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/uaccess.h>
49#include <asm/branch.h>
50
51#include "ieee754.h"
52
53/* Strap kernel emulator for full MIPS IV emulation */
54
55#ifdef __mips
56#undef __mips
57#endif
58#define __mips 4
59
60/* Function which emulates a floating point instruction. */
61
62static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
63 mips_instruction);
64
65#if __mips >= 4 && __mips != 32
66static int fpux_emu(struct pt_regs *,
67 struct mips_fpu_struct *, mips_instruction, void *__user *);
68#endif
69
70/* Further private data for which no space exists in mips_fpu_struct */
71
72#ifdef CONFIG_DEBUG_FS
73DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
74#endif
75
76/* Control registers */
77
78#define FPCREG_RID 0 /* $0 = revision id */
79#define FPCREG_CSR 31 /* $31 = csr */
80
81/* Determine rounding mode from the RM bits of the FCSR */
82#define modeindex(v) ((v) & FPU_CSR_RM)
83
84/* Convert Mips rounding mode (0..3) to IEEE library modes. */
85static const unsigned char ieee_rm[4] = {
86 [FPU_CSR_RN] = IEEE754_RN,
87 [FPU_CSR_RZ] = IEEE754_RZ,
88 [FPU_CSR_RU] = IEEE754_RU,
89 [FPU_CSR_RD] = IEEE754_RD,
90};
91/* Convert IEEE library modes to Mips rounding mode (0..3). */
92static const unsigned char mips_rm[4] = {
93 [IEEE754_RN] = FPU_CSR_RN,
94 [IEEE754_RZ] = FPU_CSR_RZ,
95 [IEEE754_RD] = FPU_CSR_RD,
96 [IEEE754_RU] = FPU_CSR_RU,
97};
98
99#if __mips >= 4
100/* convert condition code register number to csr bit */
101static const unsigned int fpucondbit[8] = {
102 FPU_CSR_COND0,
103 FPU_CSR_COND1,
104 FPU_CSR_COND2,
105 FPU_CSR_COND3,
106 FPU_CSR_COND4,
107 FPU_CSR_COND5,
108 FPU_CSR_COND6,
109 FPU_CSR_COND7
110};
111#endif
112
113
114/*
115 * Redundant with logic already in kernel/branch.c,
116 * embedded in compute_return_epc. At some point,
117 * a single subroutine should be used across both
118 * modules.
119 */
120static int isBranchInstr(mips_instruction * i)
121{
122 switch (MIPSInst_OPCODE(*i)) {
123 case spec_op:
124 switch (MIPSInst_FUNC(*i)) {
125 case jalr_op:
126 case jr_op:
127 return 1;
128 }
129 break;
130
131 case bcond_op:
132 switch (MIPSInst_RT(*i)) {
133 case bltz_op:
134 case bgez_op:
135 case bltzl_op:
136 case bgezl_op:
137 case bltzal_op:
138 case bgezal_op:
139 case bltzall_op:
140 case bgezall_op:
141 return 1;
142 }
143 break;
144
145 case j_op:
146 case jal_op:
147 case jalx_op:
148 case beq_op:
149 case bne_op:
150 case blez_op:
151 case bgtz_op:
152 case beql_op:
153 case bnel_op:
154 case blezl_op:
155 case bgtzl_op:
156 return 1;
157
158 case cop0_op:
159 case cop1_op:
160 case cop2_op:
161 case cop1x_op:
162 if (MIPSInst_RS(*i) == bc_op)
163 return 1;
164 break;
165 }
166
167 return 0;
168}
169
170/*
171 * In the Linux kernel, we support selection of FPR format on the
172 * basis of the Status.FR bit. If an FPU is not present, the FR bit
173 * is hardwired to zero, which would imply a 32-bit FPU even for
174 * 64-bit CPUs. For 64-bit kernels with no FPU we use TIF_32BIT_REGS
175 * as a proxy for the FR bit so that a 64-bit FPU is emulated. In any
176 * case, for a 32-bit kernel which uses the O32 MIPS ABI, only the
177 * even FPRs are used (Status.FR = 0).
178 */
179static inline int cop1_64bit(struct pt_regs *xcp)
180{
181 if (cpu_has_fpu)
182 return xcp->cp0_status & ST0_FR;
183#ifdef CONFIG_64BIT
184 return !test_thread_flag(TIF_32BIT_REGS);
185#else
186 return 0;
187#endif
188}
189
190#define SIFROMREG(si, x) ((si) = cop1_64bit(xcp) || !(x & 1) ? \
191 (int)ctx->fpr[x] : (int)(ctx->fpr[x & ~1] >> 32))
192
193#define SITOREG(si, x) (ctx->fpr[x & ~(cop1_64bit(xcp) == 0)] = \
194 cop1_64bit(xcp) || !(x & 1) ? \
195 ctx->fpr[x & ~1] >> 32 << 32 | (u32)(si) : \
196 ctx->fpr[x & ~1] << 32 >> 32 | (u64)(si) << 32)
197
198#define DIFROMREG(di, x) ((di) = ctx->fpr[x & ~(cop1_64bit(xcp) == 0)])
199#define DITOREG(di, x) (ctx->fpr[x & ~(cop1_64bit(xcp) == 0)] = (di))
200
201#define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
202#define SPTOREG(sp, x) SITOREG((sp).bits, x)
203#define DPFROMREG(dp, x) DIFROMREG((dp).bits, x)
204#define DPTOREG(dp, x) DITOREG((dp).bits, x)
205
206/*
207 * Emulate the single floating point instruction pointed at by EPC.
208 * Two instructions if the instruction is in a branch delay slot.
209 */
210
211static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
212 void *__user *fault_addr)
213{
214 mips_instruction ir;
215 unsigned long emulpc, contpc;
216 unsigned int cond;
217
218 if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) {
219 MIPS_FPU_EMU_INC_STATS(errors);
220 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
221 return SIGBUS;
222 }
223 if (__get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) {
224 MIPS_FPU_EMU_INC_STATS(errors);
225 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
226 return SIGSEGV;
227 }
228
229 /* XXX NEC Vr54xx bug workaround */
230 if ((xcp->cp0_cause & CAUSEF_BD) && !isBranchInstr(&ir))
231 xcp->cp0_cause &= ~CAUSEF_BD;
232
233 if (xcp->cp0_cause & CAUSEF_BD) {
234 /*
235 * The instruction to be emulated is in a branch delay slot
236 * which means that we have to emulate the branch instruction
237 * BEFORE we do the cop1 instruction.
238 *
239 * This branch could be a COP1 branch, but in that case we
240 * would have had a trap for that instruction, and would not
241 * come through this route.
242 *
243 * Linux MIPS branch emulator operates on context, updating the
244 * cp0_epc.
245 */
246 emulpc = xcp->cp0_epc + 4; /* Snapshot emulation target */
247
248 if (__compute_return_epc(xcp)) {
249#ifdef CP1DBG
250 printk("failed to emulate branch at %p\n",
251 (void *) (xcp->cp0_epc));
252#endif
253 return SIGILL;
254 }
255 if (!access_ok(VERIFY_READ, emulpc, sizeof(mips_instruction))) {
256 MIPS_FPU_EMU_INC_STATS(errors);
257 *fault_addr = (mips_instruction __user *)emulpc;
258 return SIGBUS;
259 }
260 if (__get_user(ir, (mips_instruction __user *) emulpc)) {
261 MIPS_FPU_EMU_INC_STATS(errors);
262 *fault_addr = (mips_instruction __user *)emulpc;
263 return SIGSEGV;
264 }
265 /* __compute_return_epc() will have updated cp0_epc */
266 contpc = xcp->cp0_epc;
267 /* In order not to confuse ptrace() et al, tweak context */
268 xcp->cp0_epc = emulpc - 4;
269 } else {
270 emulpc = xcp->cp0_epc;
271 contpc = xcp->cp0_epc + 4;
272 }
273
274 emul:
275 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
276 MIPS_FPU_EMU_INC_STATS(emulated);
277 switch (MIPSInst_OPCODE(ir)) {
278 case ldc1_op:{
279 u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
280 MIPSInst_SIMM(ir));
281 u64 val;
282
283 MIPS_FPU_EMU_INC_STATS(loads);
284
285 if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
286 MIPS_FPU_EMU_INC_STATS(errors);
287 *fault_addr = va;
288 return SIGBUS;
289 }
290 if (__get_user(val, va)) {
291 MIPS_FPU_EMU_INC_STATS(errors);
292 *fault_addr = va;
293 return SIGSEGV;
294 }
295 DITOREG(val, MIPSInst_RT(ir));
296 break;
297 }
298
299 case sdc1_op:{
300 u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
301 MIPSInst_SIMM(ir));
302 u64 val;
303
304 MIPS_FPU_EMU_INC_STATS(stores);
305 DIFROMREG(val, MIPSInst_RT(ir));
306 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
307 MIPS_FPU_EMU_INC_STATS(errors);
308 *fault_addr = va;
309 return SIGBUS;
310 }
311 if (__put_user(val, va)) {
312 MIPS_FPU_EMU_INC_STATS(errors);
313 *fault_addr = va;
314 return SIGSEGV;
315 }
316 break;
317 }
318
319 case lwc1_op:{
320 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
321 MIPSInst_SIMM(ir));
322 u32 val;
323
324 MIPS_FPU_EMU_INC_STATS(loads);
325 if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
326 MIPS_FPU_EMU_INC_STATS(errors);
327 *fault_addr = va;
328 return SIGBUS;
329 }
330 if (__get_user(val, va)) {
331 MIPS_FPU_EMU_INC_STATS(errors);
332 *fault_addr = va;
333 return SIGSEGV;
334 }
335 SITOREG(val, MIPSInst_RT(ir));
336 break;
337 }
338
339 case swc1_op:{
340 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
341 MIPSInst_SIMM(ir));
342 u32 val;
343
344 MIPS_FPU_EMU_INC_STATS(stores);
345 SIFROMREG(val, MIPSInst_RT(ir));
346 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
347 MIPS_FPU_EMU_INC_STATS(errors);
348 *fault_addr = va;
349 return SIGBUS;
350 }
351 if (__put_user(val, va)) {
352 MIPS_FPU_EMU_INC_STATS(errors);
353 *fault_addr = va;
354 return SIGSEGV;
355 }
356 break;
357 }
358
359 case cop1_op:
360 switch (MIPSInst_RS(ir)) {
361
362#if defined(__mips64)
363 case dmfc_op:
364 /* copregister fs -> gpr[rt] */
365 if (MIPSInst_RT(ir) != 0) {
366 DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
367 MIPSInst_RD(ir));
368 }
369 break;
370
371 case dmtc_op:
372 /* copregister fs <- rt */
373 DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
374 break;
375#endif
376
377 case mfc_op:
378 /* copregister rd -> gpr[rt] */
379 if (MIPSInst_RT(ir) != 0) {
380 SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
381 MIPSInst_RD(ir));
382 }
383 break;
384
385 case mtc_op:
386 /* copregister rd <- rt */
387 SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
388 break;
389
390 case cfc_op:{
391 /* cop control register rd -> gpr[rt] */
392 u32 value;
393
394 if (MIPSInst_RD(ir) == FPCREG_CSR) {
395 value = ctx->fcr31;
396 value = (value & ~FPU_CSR_RM) |
397 mips_rm[modeindex(value)];
398#ifdef CSRTRACE
399 printk("%p gpr[%d]<-csr=%08x\n",
400 (void *) (xcp->cp0_epc),
401 MIPSInst_RT(ir), value);
402#endif
403 }
404 else if (MIPSInst_RD(ir) == FPCREG_RID)
405 value = 0;
406 else
407 value = 0;
408 if (MIPSInst_RT(ir))
409 xcp->regs[MIPSInst_RT(ir)] = value;
410 break;
411 }
412
413 case ctc_op:{
414 /* copregister rd <- rt */
415 u32 value;
416
417 if (MIPSInst_RT(ir) == 0)
418 value = 0;
419 else
420 value = xcp->regs[MIPSInst_RT(ir)];
421
422 /* we only have one writable control reg
423 */
424 if (MIPSInst_RD(ir) == FPCREG_CSR) {
425#ifdef CSRTRACE
426 printk("%p gpr[%d]->csr=%08x\n",
427 (void *) (xcp->cp0_epc),
428 MIPSInst_RT(ir), value);
429#endif
430
431 /*
432 * Don't write reserved bits,
433 * and convert to ieee library modes
434 */
435 ctx->fcr31 = (value &
436 ~(FPU_CSR_RSVD | FPU_CSR_RM)) |
437 ieee_rm[modeindex(value)];
438 }
439 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
440 return SIGFPE;
441 }
442 break;
443 }
444
445 case bc_op:{
446 int likely = 0;
447
448 if (xcp->cp0_cause & CAUSEF_BD)
449 return SIGILL;
450
451#if __mips >= 4
452 cond = ctx->fcr31 & fpucondbit[MIPSInst_RT(ir) >> 2];
453#else
454 cond = ctx->fcr31 & FPU_CSR_COND;
455#endif
456 switch (MIPSInst_RT(ir) & 3) {
457 case bcfl_op:
458 likely = 1;
459 case bcf_op:
460 cond = !cond;
461 break;
462 case bctl_op:
463 likely = 1;
464 case bct_op:
465 break;
466 default:
467 /* thats an illegal instruction */
468 return SIGILL;
469 }
470
471 xcp->cp0_cause |= CAUSEF_BD;
472 if (cond) {
473 /* branch taken: emulate dslot
474 * instruction
475 */
476 xcp->cp0_epc += 4;
477 contpc = (xcp->cp0_epc +
478 (MIPSInst_SIMM(ir) << 2));
479
480 if (!access_ok(VERIFY_READ, xcp->cp0_epc,
481 sizeof(mips_instruction))) {
482 MIPS_FPU_EMU_INC_STATS(errors);
483 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
484 return SIGBUS;
485 }
486 if (__get_user(ir,
487 (mips_instruction __user *) xcp->cp0_epc)) {
488 MIPS_FPU_EMU_INC_STATS(errors);
489 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
490 return SIGSEGV;
491 }
492
493 switch (MIPSInst_OPCODE(ir)) {
494 case lwc1_op:
495 case swc1_op:
496#if (__mips >= 2 || defined(__mips64))
497 case ldc1_op:
498 case sdc1_op:
499#endif
500 case cop1_op:
501#if __mips >= 4 && __mips != 32
502 case cop1x_op:
503#endif
504 /* its one of ours */
505 goto emul;
506#if __mips >= 4
507 case spec_op:
508 if (MIPSInst_FUNC(ir) == movc_op)
509 goto emul;
510 break;
511#endif
512 }
513
514 /*
515 * Single step the non-cp1
516 * instruction in the dslot
517 */
518 return mips_dsemul(xcp, ir, contpc);
519 }
520 else {
521 /* branch not taken */
522 if (likely) {
523 /*
524 * branch likely nullifies
525 * dslot if not taken
526 */
527 xcp->cp0_epc += 4;
528 contpc += 4;
529 /*
530 * else continue & execute
531 * dslot as normal insn
532 */
533 }
534 }
535 break;
536 }
537
538 default:
539 if (!(MIPSInst_RS(ir) & 0x10))
540 return SIGILL;
541 {
542 int sig;
543
544 /* a real fpu computation instruction */
545 if ((sig = fpu_emu(xcp, ctx, ir)))
546 return sig;
547 }
548 }
549 break;
550
551#if __mips >= 4 && __mips != 32
552 case cop1x_op:{
553 int sig = fpux_emu(xcp, ctx, ir, fault_addr);
554 if (sig)
555 return sig;
556 break;
557 }
558#endif
559
560#if __mips >= 4
561 case spec_op:
562 if (MIPSInst_FUNC(ir) != movc_op)
563 return SIGILL;
564 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
565 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
566 xcp->regs[MIPSInst_RD(ir)] =
567 xcp->regs[MIPSInst_RS(ir)];
568 break;
569#endif
570
571 default:
572 return SIGILL;
573 }
574
575 /* we did it !! */
576 xcp->cp0_epc = contpc;
577 xcp->cp0_cause &= ~CAUSEF_BD;
578
579 return 0;
580}
581
582/*
583 * Conversion table from MIPS compare ops 48-63
584 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
585 */
586static const unsigned char cmptab[8] = {
587 0, /* cmp_0 (sig) cmp_sf */
588 IEEE754_CUN, /* cmp_un (sig) cmp_ngle */
589 IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */
590 IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */
591 IEEE754_CLT, /* cmp_olt (sig) cmp_lt */
592 IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */
593 IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */
594 IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */
595};
596
597
598#if __mips >= 4 && __mips != 32
599
600/*
601 * Additional MIPS4 instructions
602 */
603
604#define DEF3OP(name, p, f1, f2, f3) \
605static ieee754##p fpemu_##p##_##name(ieee754##p r, ieee754##p s, \
606 ieee754##p t) \
607{ \
608 struct _ieee754_csr ieee754_csr_save; \
609 s = f1(s, t); \
610 ieee754_csr_save = ieee754_csr; \
611 s = f2(s, r); \
612 ieee754_csr_save.cx |= ieee754_csr.cx; \
613 ieee754_csr_save.sx |= ieee754_csr.sx; \
614 s = f3(s); \
615 ieee754_csr.cx |= ieee754_csr_save.cx; \
616 ieee754_csr.sx |= ieee754_csr_save.sx; \
617 return s; \
618}
619
620static ieee754dp fpemu_dp_recip(ieee754dp d)
621{
622 return ieee754dp_div(ieee754dp_one(0), d);
623}
624
625static ieee754dp fpemu_dp_rsqrt(ieee754dp d)
626{
627 return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
628}
629
630static ieee754sp fpemu_sp_recip(ieee754sp s)
631{
632 return ieee754sp_div(ieee754sp_one(0), s);
633}
634
635static ieee754sp fpemu_sp_rsqrt(ieee754sp s)
636{
637 return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
638}
639
640DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
641DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
642DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
643DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
644DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
645DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
646DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
647DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
648
649static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
650 mips_instruction ir, void *__user *fault_addr)
651{
652 unsigned rcsr = 0; /* resulting csr */
653
654 MIPS_FPU_EMU_INC_STATS(cp1xops);
655
656 switch (MIPSInst_FMA_FFMT(ir)) {
657 case s_fmt:{ /* 0 */
658
659 ieee754sp(*handler) (ieee754sp, ieee754sp, ieee754sp);
660 ieee754sp fd, fr, fs, ft;
661 u32 __user *va;
662 u32 val;
663
664 switch (MIPSInst_FUNC(ir)) {
665 case lwxc1_op:
666 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
667 xcp->regs[MIPSInst_FT(ir)]);
668
669 MIPS_FPU_EMU_INC_STATS(loads);
670 if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
671 MIPS_FPU_EMU_INC_STATS(errors);
672 *fault_addr = va;
673 return SIGBUS;
674 }
675 if (__get_user(val, va)) {
676 MIPS_FPU_EMU_INC_STATS(errors);
677 *fault_addr = va;
678 return SIGSEGV;
679 }
680 SITOREG(val, MIPSInst_FD(ir));
681 break;
682
683 case swxc1_op:
684 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
685 xcp->regs[MIPSInst_FT(ir)]);
686
687 MIPS_FPU_EMU_INC_STATS(stores);
688
689 SIFROMREG(val, MIPSInst_FS(ir));
690 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
691 MIPS_FPU_EMU_INC_STATS(errors);
692 *fault_addr = va;
693 return SIGBUS;
694 }
695 if (put_user(val, va)) {
696 MIPS_FPU_EMU_INC_STATS(errors);
697 *fault_addr = va;
698 return SIGSEGV;
699 }
700 break;
701
702 case madd_s_op:
703 handler = fpemu_sp_madd;
704 goto scoptop;
705 case msub_s_op:
706 handler = fpemu_sp_msub;
707 goto scoptop;
708 case nmadd_s_op:
709 handler = fpemu_sp_nmadd;
710 goto scoptop;
711 case nmsub_s_op:
712 handler = fpemu_sp_nmsub;
713 goto scoptop;
714
715 scoptop:
716 SPFROMREG(fr, MIPSInst_FR(ir));
717 SPFROMREG(fs, MIPSInst_FS(ir));
718 SPFROMREG(ft, MIPSInst_FT(ir));
719 fd = (*handler) (fr, fs, ft);
720 SPTOREG(fd, MIPSInst_FD(ir));
721
722 copcsr:
723 if (ieee754_cxtest(IEEE754_INEXACT))
724 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
725 if (ieee754_cxtest(IEEE754_UNDERFLOW))
726 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
727 if (ieee754_cxtest(IEEE754_OVERFLOW))
728 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
729 if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
730 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
731
732 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
733 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
734 /*printk ("SIGFPE: fpu csr = %08x\n",
735 ctx->fcr31); */
736 return SIGFPE;
737 }
738
739 break;
740
741 default:
742 return SIGILL;
743 }
744 break;
745 }
746
747 case d_fmt:{ /* 1 */
748 ieee754dp(*handler) (ieee754dp, ieee754dp, ieee754dp);
749 ieee754dp fd, fr, fs, ft;
750 u64 __user *va;
751 u64 val;
752
753 switch (MIPSInst_FUNC(ir)) {
754 case ldxc1_op:
755 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
756 xcp->regs[MIPSInst_FT(ir)]);
757
758 MIPS_FPU_EMU_INC_STATS(loads);
759 if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
760 MIPS_FPU_EMU_INC_STATS(errors);
761 *fault_addr = va;
762 return SIGBUS;
763 }
764 if (__get_user(val, va)) {
765 MIPS_FPU_EMU_INC_STATS(errors);
766 *fault_addr = va;
767 return SIGSEGV;
768 }
769 DITOREG(val, MIPSInst_FD(ir));
770 break;
771
772 case sdxc1_op:
773 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
774 xcp->regs[MIPSInst_FT(ir)]);
775
776 MIPS_FPU_EMU_INC_STATS(stores);
777 DIFROMREG(val, MIPSInst_FS(ir));
778 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
779 MIPS_FPU_EMU_INC_STATS(errors);
780 *fault_addr = va;
781 return SIGBUS;
782 }
783 if (__put_user(val, va)) {
784 MIPS_FPU_EMU_INC_STATS(errors);
785 *fault_addr = va;
786 return SIGSEGV;
787 }
788 break;
789
790 case madd_d_op:
791 handler = fpemu_dp_madd;
792 goto dcoptop;
793 case msub_d_op:
794 handler = fpemu_dp_msub;
795 goto dcoptop;
796 case nmadd_d_op:
797 handler = fpemu_dp_nmadd;
798 goto dcoptop;
799 case nmsub_d_op:
800 handler = fpemu_dp_nmsub;
801 goto dcoptop;
802
803 dcoptop:
804 DPFROMREG(fr, MIPSInst_FR(ir));
805 DPFROMREG(fs, MIPSInst_FS(ir));
806 DPFROMREG(ft, MIPSInst_FT(ir));
807 fd = (*handler) (fr, fs, ft);
808 DPTOREG(fd, MIPSInst_FD(ir));
809 goto copcsr;
810
811 default:
812 return SIGILL;
813 }
814 break;
815 }
816
817 case 0x7: /* 7 */
818 if (MIPSInst_FUNC(ir) != pfetch_op) {
819 return SIGILL;
820 }
821 /* ignore prefx operation */
822 break;
823
824 default:
825 return SIGILL;
826 }
827
828 return 0;
829}
830#endif
831
832
833
834/*
835 * Emulate a single COP1 arithmetic instruction.
836 */
837static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
838 mips_instruction ir)
839{
840 int rfmt; /* resulting format */
841 unsigned rcsr = 0; /* resulting csr */
842 unsigned cond;
843 union {
844 ieee754dp d;
845 ieee754sp s;
846 int w;
847#ifdef __mips64
848 s64 l;
849#endif
850 } rv; /* resulting value */
851
852 MIPS_FPU_EMU_INC_STATS(cp1ops);
853 switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
854 case s_fmt:{ /* 0 */
855 union {
856 ieee754sp(*b) (ieee754sp, ieee754sp);
857 ieee754sp(*u) (ieee754sp);
858 } handler;
859
860 switch (MIPSInst_FUNC(ir)) {
861 /* binary ops */
862 case fadd_op:
863 handler.b = ieee754sp_add;
864 goto scopbop;
865 case fsub_op:
866 handler.b = ieee754sp_sub;
867 goto scopbop;
868 case fmul_op:
869 handler.b = ieee754sp_mul;
870 goto scopbop;
871 case fdiv_op:
872 handler.b = ieee754sp_div;
873 goto scopbop;
874
875 /* unary ops */
876#if __mips >= 2 || defined(__mips64)
877 case fsqrt_op:
878 handler.u = ieee754sp_sqrt;
879 goto scopuop;
880#endif
881#if __mips >= 4 && __mips != 32
882 case frsqrt_op:
883 handler.u = fpemu_sp_rsqrt;
884 goto scopuop;
885 case frecip_op:
886 handler.u = fpemu_sp_recip;
887 goto scopuop;
888#endif
889#if __mips >= 4
890 case fmovc_op:
891 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
892 if (((ctx->fcr31 & cond) != 0) !=
893 ((MIPSInst_FT(ir) & 1) != 0))
894 return 0;
895 SPFROMREG(rv.s, MIPSInst_FS(ir));
896 break;
897 case fmovz_op:
898 if (xcp->regs[MIPSInst_FT(ir)] != 0)
899 return 0;
900 SPFROMREG(rv.s, MIPSInst_FS(ir));
901 break;
902 case fmovn_op:
903 if (xcp->regs[MIPSInst_FT(ir)] == 0)
904 return 0;
905 SPFROMREG(rv.s, MIPSInst_FS(ir));
906 break;
907#endif
908 case fabs_op:
909 handler.u = ieee754sp_abs;
910 goto scopuop;
911 case fneg_op:
912 handler.u = ieee754sp_neg;
913 goto scopuop;
914 case fmov_op:
915 /* an easy one */
916 SPFROMREG(rv.s, MIPSInst_FS(ir));
917 goto copcsr;
918
919 /* binary op on handler */
920 scopbop:
921 {
922 ieee754sp fs, ft;
923
924 SPFROMREG(fs, MIPSInst_FS(ir));
925 SPFROMREG(ft, MIPSInst_FT(ir));
926
927 rv.s = (*handler.b) (fs, ft);
928 goto copcsr;
929 }
930 scopuop:
931 {
932 ieee754sp fs;
933
934 SPFROMREG(fs, MIPSInst_FS(ir));
935 rv.s = (*handler.u) (fs);
936 goto copcsr;
937 }
938 copcsr:
939 if (ieee754_cxtest(IEEE754_INEXACT))
940 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
941 if (ieee754_cxtest(IEEE754_UNDERFLOW))
942 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
943 if (ieee754_cxtest(IEEE754_OVERFLOW))
944 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
945 if (ieee754_cxtest(IEEE754_ZERO_DIVIDE))
946 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
947 if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
948 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
949 break;
950
951 /* unary conv ops */
952 case fcvts_op:
953 return SIGILL; /* not defined */
954 case fcvtd_op:{
955 ieee754sp fs;
956
957 SPFROMREG(fs, MIPSInst_FS(ir));
958 rv.d = ieee754dp_fsp(fs);
959 rfmt = d_fmt;
960 goto copcsr;
961 }
962 case fcvtw_op:{
963 ieee754sp fs;
964
965 SPFROMREG(fs, MIPSInst_FS(ir));
966 rv.w = ieee754sp_tint(fs);
967 rfmt = w_fmt;
968 goto copcsr;
969 }
970
971#if __mips >= 2 || defined(__mips64)
972 case fround_op:
973 case ftrunc_op:
974 case fceil_op:
975 case ffloor_op:{
976 unsigned int oldrm = ieee754_csr.rm;
977 ieee754sp fs;
978
979 SPFROMREG(fs, MIPSInst_FS(ir));
980 ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
981 rv.w = ieee754sp_tint(fs);
982 ieee754_csr.rm = oldrm;
983 rfmt = w_fmt;
984 goto copcsr;
985 }
986#endif /* __mips >= 2 */
987
988#if defined(__mips64)
989 case fcvtl_op:{
990 ieee754sp fs;
991
992 SPFROMREG(fs, MIPSInst_FS(ir));
993 rv.l = ieee754sp_tlong(fs);
994 rfmt = l_fmt;
995 goto copcsr;
996 }
997
998 case froundl_op:
999 case ftruncl_op:
1000 case fceill_op:
1001 case ffloorl_op:{
1002 unsigned int oldrm = ieee754_csr.rm;
1003 ieee754sp fs;
1004
1005 SPFROMREG(fs, MIPSInst_FS(ir));
1006 ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1007 rv.l = ieee754sp_tlong(fs);
1008 ieee754_csr.rm = oldrm;
1009 rfmt = l_fmt;
1010 goto copcsr;
1011 }
1012#endif /* defined(__mips64) */
1013
1014 default:
1015 if (MIPSInst_FUNC(ir) >= fcmp_op) {
1016 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1017 ieee754sp fs, ft;
1018
1019 SPFROMREG(fs, MIPSInst_FS(ir));
1020 SPFROMREG(ft, MIPSInst_FT(ir));
1021 rv.w = ieee754sp_cmp(fs, ft,
1022 cmptab[cmpop & 0x7], cmpop & 0x8);
1023 rfmt = -1;
1024 if ((cmpop & 0x8) && ieee754_cxtest
1025 (IEEE754_INVALID_OPERATION))
1026 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1027 else
1028 goto copcsr;
1029
1030 }
1031 else {
1032 return SIGILL;
1033 }
1034 break;
1035 }
1036 break;
1037 }
1038
1039 case d_fmt:{
1040 union {
1041 ieee754dp(*b) (ieee754dp, ieee754dp);
1042 ieee754dp(*u) (ieee754dp);
1043 } handler;
1044
1045 switch (MIPSInst_FUNC(ir)) {
1046 /* binary ops */
1047 case fadd_op:
1048 handler.b = ieee754dp_add;
1049 goto dcopbop;
1050 case fsub_op:
1051 handler.b = ieee754dp_sub;
1052 goto dcopbop;
1053 case fmul_op:
1054 handler.b = ieee754dp_mul;
1055 goto dcopbop;
1056 case fdiv_op:
1057 handler.b = ieee754dp_div;
1058 goto dcopbop;
1059
1060 /* unary ops */
1061#if __mips >= 2 || defined(__mips64)
1062 case fsqrt_op:
1063 handler.u = ieee754dp_sqrt;
1064 goto dcopuop;
1065#endif
1066#if __mips >= 4 && __mips != 32
1067 case frsqrt_op:
1068 handler.u = fpemu_dp_rsqrt;
1069 goto dcopuop;
1070 case frecip_op:
1071 handler.u = fpemu_dp_recip;
1072 goto dcopuop;
1073#endif
1074#if __mips >= 4
1075 case fmovc_op:
1076 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1077 if (((ctx->fcr31 & cond) != 0) !=
1078 ((MIPSInst_FT(ir) & 1) != 0))
1079 return 0;
1080 DPFROMREG(rv.d, MIPSInst_FS(ir));
1081 break;
1082 case fmovz_op:
1083 if (xcp->regs[MIPSInst_FT(ir)] != 0)
1084 return 0;
1085 DPFROMREG(rv.d, MIPSInst_FS(ir));
1086 break;
1087 case fmovn_op:
1088 if (xcp->regs[MIPSInst_FT(ir)] == 0)
1089 return 0;
1090 DPFROMREG(rv.d, MIPSInst_FS(ir));
1091 break;
1092#endif
1093 case fabs_op:
1094 handler.u = ieee754dp_abs;
1095 goto dcopuop;
1096
1097 case fneg_op:
1098 handler.u = ieee754dp_neg;
1099 goto dcopuop;
1100
1101 case fmov_op:
1102 /* an easy one */
1103 DPFROMREG(rv.d, MIPSInst_FS(ir));
1104 goto copcsr;
1105
1106 /* binary op on handler */
1107 dcopbop:{
1108 ieee754dp fs, ft;
1109
1110 DPFROMREG(fs, MIPSInst_FS(ir));
1111 DPFROMREG(ft, MIPSInst_FT(ir));
1112
1113 rv.d = (*handler.b) (fs, ft);
1114 goto copcsr;
1115 }
1116 dcopuop:{
1117 ieee754dp fs;
1118
1119 DPFROMREG(fs, MIPSInst_FS(ir));
1120 rv.d = (*handler.u) (fs);
1121 goto copcsr;
1122 }
1123
1124 /* unary conv ops */
1125 case fcvts_op:{
1126 ieee754dp fs;
1127
1128 DPFROMREG(fs, MIPSInst_FS(ir));
1129 rv.s = ieee754sp_fdp(fs);
1130 rfmt = s_fmt;
1131 goto copcsr;
1132 }
1133 case fcvtd_op:
1134 return SIGILL; /* not defined */
1135
1136 case fcvtw_op:{
1137 ieee754dp fs;
1138
1139 DPFROMREG(fs, MIPSInst_FS(ir));
1140 rv.w = ieee754dp_tint(fs); /* wrong */
1141 rfmt = w_fmt;
1142 goto copcsr;
1143 }
1144
1145#if __mips >= 2 || defined(__mips64)
1146 case fround_op:
1147 case ftrunc_op:
1148 case fceil_op:
1149 case ffloor_op:{
1150 unsigned int oldrm = ieee754_csr.rm;
1151 ieee754dp fs;
1152
1153 DPFROMREG(fs, MIPSInst_FS(ir));
1154 ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1155 rv.w = ieee754dp_tint(fs);
1156 ieee754_csr.rm = oldrm;
1157 rfmt = w_fmt;
1158 goto copcsr;
1159 }
1160#endif
1161
1162#if defined(__mips64)
1163 case fcvtl_op:{
1164 ieee754dp fs;
1165
1166 DPFROMREG(fs, MIPSInst_FS(ir));
1167 rv.l = ieee754dp_tlong(fs);
1168 rfmt = l_fmt;
1169 goto copcsr;
1170 }
1171
1172 case froundl_op:
1173 case ftruncl_op:
1174 case fceill_op:
1175 case ffloorl_op:{
1176 unsigned int oldrm = ieee754_csr.rm;
1177 ieee754dp fs;
1178
1179 DPFROMREG(fs, MIPSInst_FS(ir));
1180 ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1181 rv.l = ieee754dp_tlong(fs);
1182 ieee754_csr.rm = oldrm;
1183 rfmt = l_fmt;
1184 goto copcsr;
1185 }
1186#endif /* __mips >= 3 */
1187
1188 default:
1189 if (MIPSInst_FUNC(ir) >= fcmp_op) {
1190 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1191 ieee754dp fs, ft;
1192
1193 DPFROMREG(fs, MIPSInst_FS(ir));
1194 DPFROMREG(ft, MIPSInst_FT(ir));
1195 rv.w = ieee754dp_cmp(fs, ft,
1196 cmptab[cmpop & 0x7], cmpop & 0x8);
1197 rfmt = -1;
1198 if ((cmpop & 0x8)
1199 &&
1200 ieee754_cxtest
1201 (IEEE754_INVALID_OPERATION))
1202 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1203 else
1204 goto copcsr;
1205
1206 }
1207 else {
1208 return SIGILL;
1209 }
1210 break;
1211 }
1212 break;
1213 }
1214
1215 case w_fmt:{
1216 ieee754sp fs;
1217
1218 switch (MIPSInst_FUNC(ir)) {
1219 case fcvts_op:
1220 /* convert word to single precision real */
1221 SPFROMREG(fs, MIPSInst_FS(ir));
1222 rv.s = ieee754sp_fint(fs.bits);
1223 rfmt = s_fmt;
1224 goto copcsr;
1225 case fcvtd_op:
1226 /* convert word to double precision real */
1227 SPFROMREG(fs, MIPSInst_FS(ir));
1228 rv.d = ieee754dp_fint(fs.bits);
1229 rfmt = d_fmt;
1230 goto copcsr;
1231 default:
1232 return SIGILL;
1233 }
1234 break;
1235 }
1236
1237#if defined(__mips64)
1238 case l_fmt:{
1239 switch (MIPSInst_FUNC(ir)) {
1240 case fcvts_op:
1241 /* convert long to single precision real */
1242 rv.s = ieee754sp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1243 rfmt = s_fmt;
1244 goto copcsr;
1245 case fcvtd_op:
1246 /* convert long to double precision real */
1247 rv.d = ieee754dp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1248 rfmt = d_fmt;
1249 goto copcsr;
1250 default:
1251 return SIGILL;
1252 }
1253 break;
1254 }
1255#endif
1256
1257 default:
1258 return SIGILL;
1259 }
1260
1261 /*
1262 * Update the fpu CSR register for this operation.
1263 * If an exception is required, generate a tidy SIGFPE exception,
1264 * without updating the result register.
1265 * Note: cause exception bits do not accumulate, they are rewritten
1266 * for each op; only the flag/sticky bits accumulate.
1267 */
1268 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1269 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1270 /*printk ("SIGFPE: fpu csr = %08x\n",ctx->fcr31); */
1271 return SIGFPE;
1272 }
1273
1274 /*
1275 * Now we can safely write the result back to the register file.
1276 */
1277 switch (rfmt) {
1278 case -1:{
1279#if __mips >= 4
1280 cond = fpucondbit[MIPSInst_FD(ir) >> 2];
1281#else
1282 cond = FPU_CSR_COND;
1283#endif
1284 if (rv.w)
1285 ctx->fcr31 |= cond;
1286 else
1287 ctx->fcr31 &= ~cond;
1288 break;
1289 }
1290 case d_fmt:
1291 DPTOREG(rv.d, MIPSInst_FD(ir));
1292 break;
1293 case s_fmt:
1294 SPTOREG(rv.s, MIPSInst_FD(ir));
1295 break;
1296 case w_fmt:
1297 SITOREG(rv.w, MIPSInst_FD(ir));
1298 break;
1299#if defined(__mips64)
1300 case l_fmt:
1301 DITOREG(rv.l, MIPSInst_FD(ir));
1302 break;
1303#endif
1304 default:
1305 return SIGILL;
1306 }
1307
1308 return 0;
1309}
1310
1311int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1312 int has_fpu, void *__user *fault_addr)
1313{
1314 unsigned long oldepc, prevepc;
1315 mips_instruction insn;
1316 int sig = 0;
1317
1318 oldepc = xcp->cp0_epc;
1319 do {
1320 prevepc = xcp->cp0_epc;
1321
1322 if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) {
1323 MIPS_FPU_EMU_INC_STATS(errors);
1324 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
1325 return SIGBUS;
1326 }
1327 if (__get_user(insn, (mips_instruction __user *) xcp->cp0_epc)) {
1328 MIPS_FPU_EMU_INC_STATS(errors);
1329 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
1330 return SIGSEGV;
1331 }
1332 if (insn == 0)
1333 xcp->cp0_epc += 4; /* skip nops */
1334 else {
1335 /*
1336 * The 'ieee754_csr' is an alias of
1337 * ctx->fcr31. No need to copy ctx->fcr31 to
1338 * ieee754_csr. But ieee754_csr.rm is ieee
1339 * library modes. (not mips rounding mode)
1340 */
1341 /* convert to ieee library modes */
1342 ieee754_csr.rm = ieee_rm[ieee754_csr.rm];
1343 sig = cop1Emulate(xcp, ctx, fault_addr);
1344 /* revert to mips rounding mode */
1345 ieee754_csr.rm = mips_rm[ieee754_csr.rm];
1346 }
1347
1348 if (has_fpu)
1349 break;
1350 if (sig)
1351 break;
1352
1353 cond_resched();
1354 } while (xcp->cp0_epc > prevepc);
1355
1356 /* SIGILL indicates a non-fpu instruction */
1357 if (sig == SIGILL && xcp->cp0_epc != oldepc)
1358 /* but if epc has advanced, then ignore it */
1359 sig = 0;
1360
1361 return sig;
1362}
1363
1364#ifdef CONFIG_DEBUG_FS
1365
1366static int fpuemu_stat_get(void *data, u64 *val)
1367{
1368 int cpu;
1369 unsigned long sum = 0;
1370 for_each_online_cpu(cpu) {
1371 struct mips_fpu_emulator_stats *ps;
1372 local_t *pv;
1373 ps = &per_cpu(fpuemustats, cpu);
1374 pv = (void *)ps + (unsigned long)data;
1375 sum += local_read(pv);
1376 }
1377 *val = sum;
1378 return 0;
1379}
1380DEFINE_SIMPLE_ATTRIBUTE(fops_fpuemu_stat, fpuemu_stat_get, NULL, "%llu\n");
1381
1382extern struct dentry *mips_debugfs_dir;
1383static int __init debugfs_fpuemu(void)
1384{
1385 struct dentry *d, *dir;
1386
1387 if (!mips_debugfs_dir)
1388 return -ENODEV;
1389 dir = debugfs_create_dir("fpuemustats", mips_debugfs_dir);
1390 if (!dir)
1391 return -ENOMEM;
1392
1393#define FPU_STAT_CREATE(M) \
1394 do { \
1395 d = debugfs_create_file(#M , S_IRUGO, dir, \
1396 (void *)offsetof(struct mips_fpu_emulator_stats, M), \
1397 &fops_fpuemu_stat); \
1398 if (!d) \
1399 return -ENOMEM; \
1400 } while (0)
1401
1402 FPU_STAT_CREATE(emulated);
1403 FPU_STAT_CREATE(loads);
1404 FPU_STAT_CREATE(stores);
1405 FPU_STAT_CREATE(cp1ops);
1406 FPU_STAT_CREATE(cp1xops);
1407 FPU_STAT_CREATE(errors);
1408
1409 return 0;
1410}
1411__initcall(debugfs_fpuemu);
1412#endif
1/*
2 * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator
3 *
4 * MIPS floating point support
5 * Copyright (C) 1994-2000 Algorithmics Ltd.
6 *
7 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
8 * Copyright (C) 2000 MIPS Technologies, Inc.
9 *
10 * This program is free software; you can distribute it and/or modify it
11 * under the terms of the GNU General Public License (Version 2) as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 * for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
22 *
23 * A complete emulator for MIPS coprocessor 1 instructions. This is
24 * required for #float(switch) or #float(trap), where it catches all
25 * COP1 instructions via the "CoProcessor Unusable" exception.
26 *
27 * More surprisingly it is also required for #float(ieee), to help out
28 * the hardware FPU at the boundaries of the IEEE-754 representation
29 * (denormalised values, infinities, underflow, etc). It is made
30 * quite nasty because emulation of some non-COP1 instructions is
31 * required, e.g. in branch delay slots.
32 *
33 * Note if you know that you won't have an FPU, then you'll get much
34 * better performance by compiling with -msoft-float!
35 */
36#include <linux/sched.h>
37#include <linux/debugfs.h>
38#include <linux/percpu-defs.h>
39#include <linux/perf_event.h>
40
41#include <asm/branch.h>
42#include <asm/inst.h>
43#include <asm/ptrace.h>
44#include <asm/signal.h>
45#include <linux/uaccess.h>
46
47#include <asm/cpu-info.h>
48#include <asm/processor.h>
49#include <asm/fpu_emulator.h>
50#include <asm/fpu.h>
51#include <asm/mips-r2-to-r6-emul.h>
52
53#include "ieee754.h"
54
55/* Function which emulates a floating point instruction. */
56
57static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
58 mips_instruction);
59
60static int fpux_emu(struct pt_regs *,
61 struct mips_fpu_struct *, mips_instruction, void *__user *);
62
63/* Control registers */
64
65#define FPCREG_RID 0 /* $0 = revision id */
66#define FPCREG_FCCR 25 /* $25 = fccr */
67#define FPCREG_FEXR 26 /* $26 = fexr */
68#define FPCREG_FENR 28 /* $28 = fenr */
69#define FPCREG_CSR 31 /* $31 = csr */
70
71/* convert condition code register number to csr bit */
72const unsigned int fpucondbit[8] = {
73 FPU_CSR_COND,
74 FPU_CSR_COND1,
75 FPU_CSR_COND2,
76 FPU_CSR_COND3,
77 FPU_CSR_COND4,
78 FPU_CSR_COND5,
79 FPU_CSR_COND6,
80 FPU_CSR_COND7
81};
82
83/* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
84static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
85static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
86static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
87static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
88
89/*
90 * This functions translates a 32-bit microMIPS instruction
91 * into a 32-bit MIPS32 instruction. Returns 0 on success
92 * and SIGILL otherwise.
93 */
94static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
95{
96 union mips_instruction insn = *insn_ptr;
97 union mips_instruction mips32_insn = insn;
98 int func, fmt, op;
99
100 switch (insn.mm_i_format.opcode) {
101 case mm_ldc132_op:
102 mips32_insn.mm_i_format.opcode = ldc1_op;
103 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
104 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
105 break;
106 case mm_lwc132_op:
107 mips32_insn.mm_i_format.opcode = lwc1_op;
108 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
109 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
110 break;
111 case mm_sdc132_op:
112 mips32_insn.mm_i_format.opcode = sdc1_op;
113 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
114 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
115 break;
116 case mm_swc132_op:
117 mips32_insn.mm_i_format.opcode = swc1_op;
118 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
119 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
120 break;
121 case mm_pool32i_op:
122 /* NOTE: offset is << by 1 if in microMIPS mode. */
123 if ((insn.mm_i_format.rt == mm_bc1f_op) ||
124 (insn.mm_i_format.rt == mm_bc1t_op)) {
125 mips32_insn.fb_format.opcode = cop1_op;
126 mips32_insn.fb_format.bc = bc_op;
127 mips32_insn.fb_format.flag =
128 (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
129 } else
130 return SIGILL;
131 break;
132 case mm_pool32f_op:
133 switch (insn.mm_fp0_format.func) {
134 case mm_32f_01_op:
135 case mm_32f_11_op:
136 case mm_32f_02_op:
137 case mm_32f_12_op:
138 case mm_32f_41_op:
139 case mm_32f_51_op:
140 case mm_32f_42_op:
141 case mm_32f_52_op:
142 op = insn.mm_fp0_format.func;
143 if (op == mm_32f_01_op)
144 func = madd_s_op;
145 else if (op == mm_32f_11_op)
146 func = madd_d_op;
147 else if (op == mm_32f_02_op)
148 func = nmadd_s_op;
149 else if (op == mm_32f_12_op)
150 func = nmadd_d_op;
151 else if (op == mm_32f_41_op)
152 func = msub_s_op;
153 else if (op == mm_32f_51_op)
154 func = msub_d_op;
155 else if (op == mm_32f_42_op)
156 func = nmsub_s_op;
157 else
158 func = nmsub_d_op;
159 mips32_insn.fp6_format.opcode = cop1x_op;
160 mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
161 mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
162 mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
163 mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
164 mips32_insn.fp6_format.func = func;
165 break;
166 case mm_32f_10_op:
167 func = -1; /* Invalid */
168 op = insn.mm_fp5_format.op & 0x7;
169 if (op == mm_ldxc1_op)
170 func = ldxc1_op;
171 else if (op == mm_sdxc1_op)
172 func = sdxc1_op;
173 else if (op == mm_lwxc1_op)
174 func = lwxc1_op;
175 else if (op == mm_swxc1_op)
176 func = swxc1_op;
177
178 if (func != -1) {
179 mips32_insn.r_format.opcode = cop1x_op;
180 mips32_insn.r_format.rs =
181 insn.mm_fp5_format.base;
182 mips32_insn.r_format.rt =
183 insn.mm_fp5_format.index;
184 mips32_insn.r_format.rd = 0;
185 mips32_insn.r_format.re = insn.mm_fp5_format.fd;
186 mips32_insn.r_format.func = func;
187 } else
188 return SIGILL;
189 break;
190 case mm_32f_40_op:
191 op = -1; /* Invalid */
192 if (insn.mm_fp2_format.op == mm_fmovt_op)
193 op = 1;
194 else if (insn.mm_fp2_format.op == mm_fmovf_op)
195 op = 0;
196 if (op != -1) {
197 mips32_insn.fp0_format.opcode = cop1_op;
198 mips32_insn.fp0_format.fmt =
199 sdps_format[insn.mm_fp2_format.fmt];
200 mips32_insn.fp0_format.ft =
201 (insn.mm_fp2_format.cc<<2) + op;
202 mips32_insn.fp0_format.fs =
203 insn.mm_fp2_format.fs;
204 mips32_insn.fp0_format.fd =
205 insn.mm_fp2_format.fd;
206 mips32_insn.fp0_format.func = fmovc_op;
207 } else
208 return SIGILL;
209 break;
210 case mm_32f_60_op:
211 func = -1; /* Invalid */
212 if (insn.mm_fp0_format.op == mm_fadd_op)
213 func = fadd_op;
214 else if (insn.mm_fp0_format.op == mm_fsub_op)
215 func = fsub_op;
216 else if (insn.mm_fp0_format.op == mm_fmul_op)
217 func = fmul_op;
218 else if (insn.mm_fp0_format.op == mm_fdiv_op)
219 func = fdiv_op;
220 if (func != -1) {
221 mips32_insn.fp0_format.opcode = cop1_op;
222 mips32_insn.fp0_format.fmt =
223 sdps_format[insn.mm_fp0_format.fmt];
224 mips32_insn.fp0_format.ft =
225 insn.mm_fp0_format.ft;
226 mips32_insn.fp0_format.fs =
227 insn.mm_fp0_format.fs;
228 mips32_insn.fp0_format.fd =
229 insn.mm_fp0_format.fd;
230 mips32_insn.fp0_format.func = func;
231 } else
232 return SIGILL;
233 break;
234 case mm_32f_70_op:
235 func = -1; /* Invalid */
236 if (insn.mm_fp0_format.op == mm_fmovn_op)
237 func = fmovn_op;
238 else if (insn.mm_fp0_format.op == mm_fmovz_op)
239 func = fmovz_op;
240 if (func != -1) {
241 mips32_insn.fp0_format.opcode = cop1_op;
242 mips32_insn.fp0_format.fmt =
243 sdps_format[insn.mm_fp0_format.fmt];
244 mips32_insn.fp0_format.ft =
245 insn.mm_fp0_format.ft;
246 mips32_insn.fp0_format.fs =
247 insn.mm_fp0_format.fs;
248 mips32_insn.fp0_format.fd =
249 insn.mm_fp0_format.fd;
250 mips32_insn.fp0_format.func = func;
251 } else
252 return SIGILL;
253 break;
254 case mm_32f_73_op: /* POOL32FXF */
255 switch (insn.mm_fp1_format.op) {
256 case mm_movf0_op:
257 case mm_movf1_op:
258 case mm_movt0_op:
259 case mm_movt1_op:
260 if ((insn.mm_fp1_format.op & 0x7f) ==
261 mm_movf0_op)
262 op = 0;
263 else
264 op = 1;
265 mips32_insn.r_format.opcode = spec_op;
266 mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
267 mips32_insn.r_format.rt =
268 (insn.mm_fp4_format.cc << 2) + op;
269 mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
270 mips32_insn.r_format.re = 0;
271 mips32_insn.r_format.func = movc_op;
272 break;
273 case mm_fcvtd0_op:
274 case mm_fcvtd1_op:
275 case mm_fcvts0_op:
276 case mm_fcvts1_op:
277 if ((insn.mm_fp1_format.op & 0x7f) ==
278 mm_fcvtd0_op) {
279 func = fcvtd_op;
280 fmt = swl_format[insn.mm_fp3_format.fmt];
281 } else {
282 func = fcvts_op;
283 fmt = dwl_format[insn.mm_fp3_format.fmt];
284 }
285 mips32_insn.fp0_format.opcode = cop1_op;
286 mips32_insn.fp0_format.fmt = fmt;
287 mips32_insn.fp0_format.ft = 0;
288 mips32_insn.fp0_format.fs =
289 insn.mm_fp3_format.fs;
290 mips32_insn.fp0_format.fd =
291 insn.mm_fp3_format.rt;
292 mips32_insn.fp0_format.func = func;
293 break;
294 case mm_fmov0_op:
295 case mm_fmov1_op:
296 case mm_fabs0_op:
297 case mm_fabs1_op:
298 case mm_fneg0_op:
299 case mm_fneg1_op:
300 if ((insn.mm_fp1_format.op & 0x7f) ==
301 mm_fmov0_op)
302 func = fmov_op;
303 else if ((insn.mm_fp1_format.op & 0x7f) ==
304 mm_fabs0_op)
305 func = fabs_op;
306 else
307 func = fneg_op;
308 mips32_insn.fp0_format.opcode = cop1_op;
309 mips32_insn.fp0_format.fmt =
310 sdps_format[insn.mm_fp3_format.fmt];
311 mips32_insn.fp0_format.ft = 0;
312 mips32_insn.fp0_format.fs =
313 insn.mm_fp3_format.fs;
314 mips32_insn.fp0_format.fd =
315 insn.mm_fp3_format.rt;
316 mips32_insn.fp0_format.func = func;
317 break;
318 case mm_ffloorl_op:
319 case mm_ffloorw_op:
320 case mm_fceill_op:
321 case mm_fceilw_op:
322 case mm_ftruncl_op:
323 case mm_ftruncw_op:
324 case mm_froundl_op:
325 case mm_froundw_op:
326 case mm_fcvtl_op:
327 case mm_fcvtw_op:
328 if (insn.mm_fp1_format.op == mm_ffloorl_op)
329 func = ffloorl_op;
330 else if (insn.mm_fp1_format.op == mm_ffloorw_op)
331 func = ffloor_op;
332 else if (insn.mm_fp1_format.op == mm_fceill_op)
333 func = fceill_op;
334 else if (insn.mm_fp1_format.op == mm_fceilw_op)
335 func = fceil_op;
336 else if (insn.mm_fp1_format.op == mm_ftruncl_op)
337 func = ftruncl_op;
338 else if (insn.mm_fp1_format.op == mm_ftruncw_op)
339 func = ftrunc_op;
340 else if (insn.mm_fp1_format.op == mm_froundl_op)
341 func = froundl_op;
342 else if (insn.mm_fp1_format.op == mm_froundw_op)
343 func = fround_op;
344 else if (insn.mm_fp1_format.op == mm_fcvtl_op)
345 func = fcvtl_op;
346 else
347 func = fcvtw_op;
348 mips32_insn.fp0_format.opcode = cop1_op;
349 mips32_insn.fp0_format.fmt =
350 sd_format[insn.mm_fp1_format.fmt];
351 mips32_insn.fp0_format.ft = 0;
352 mips32_insn.fp0_format.fs =
353 insn.mm_fp1_format.fs;
354 mips32_insn.fp0_format.fd =
355 insn.mm_fp1_format.rt;
356 mips32_insn.fp0_format.func = func;
357 break;
358 case mm_frsqrt_op:
359 case mm_fsqrt_op:
360 case mm_frecip_op:
361 if (insn.mm_fp1_format.op == mm_frsqrt_op)
362 func = frsqrt_op;
363 else if (insn.mm_fp1_format.op == mm_fsqrt_op)
364 func = fsqrt_op;
365 else
366 func = frecip_op;
367 mips32_insn.fp0_format.opcode = cop1_op;
368 mips32_insn.fp0_format.fmt =
369 sdps_format[insn.mm_fp1_format.fmt];
370 mips32_insn.fp0_format.ft = 0;
371 mips32_insn.fp0_format.fs =
372 insn.mm_fp1_format.fs;
373 mips32_insn.fp0_format.fd =
374 insn.mm_fp1_format.rt;
375 mips32_insn.fp0_format.func = func;
376 break;
377 case mm_mfc1_op:
378 case mm_mtc1_op:
379 case mm_cfc1_op:
380 case mm_ctc1_op:
381 case mm_mfhc1_op:
382 case mm_mthc1_op:
383 if (insn.mm_fp1_format.op == mm_mfc1_op)
384 op = mfc_op;
385 else if (insn.mm_fp1_format.op == mm_mtc1_op)
386 op = mtc_op;
387 else if (insn.mm_fp1_format.op == mm_cfc1_op)
388 op = cfc_op;
389 else if (insn.mm_fp1_format.op == mm_ctc1_op)
390 op = ctc_op;
391 else if (insn.mm_fp1_format.op == mm_mfhc1_op)
392 op = mfhc_op;
393 else
394 op = mthc_op;
395 mips32_insn.fp1_format.opcode = cop1_op;
396 mips32_insn.fp1_format.op = op;
397 mips32_insn.fp1_format.rt =
398 insn.mm_fp1_format.rt;
399 mips32_insn.fp1_format.fs =
400 insn.mm_fp1_format.fs;
401 mips32_insn.fp1_format.fd = 0;
402 mips32_insn.fp1_format.func = 0;
403 break;
404 default:
405 return SIGILL;
406 }
407 break;
408 case mm_32f_74_op: /* c.cond.fmt */
409 mips32_insn.fp0_format.opcode = cop1_op;
410 mips32_insn.fp0_format.fmt =
411 sdps_format[insn.mm_fp4_format.fmt];
412 mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
413 mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
414 mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
415 mips32_insn.fp0_format.func =
416 insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
417 break;
418 default:
419 return SIGILL;
420 }
421 break;
422 default:
423 return SIGILL;
424 }
425
426 *insn_ptr = mips32_insn;
427 return 0;
428}
429
430/*
431 * Redundant with logic already in kernel/branch.c,
432 * embedded in compute_return_epc. At some point,
433 * a single subroutine should be used across both
434 * modules.
435 */
436int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
437 unsigned long *contpc)
438{
439 union mips_instruction insn = (union mips_instruction)dec_insn.insn;
440 unsigned int fcr31;
441 unsigned int bit = 0;
442
443 switch (insn.i_format.opcode) {
444 case spec_op:
445 switch (insn.r_format.func) {
446 case jalr_op:
447 if (insn.r_format.rd != 0) {
448 regs->regs[insn.r_format.rd] =
449 regs->cp0_epc + dec_insn.pc_inc +
450 dec_insn.next_pc_inc;
451 }
452 /* Fall through */
453 case jr_op:
454 /* For R6, JR already emulated in jalr_op */
455 if (NO_R6EMU && insn.r_format.func == jr_op)
456 break;
457 *contpc = regs->regs[insn.r_format.rs];
458 return 1;
459 }
460 break;
461 case bcond_op:
462 switch (insn.i_format.rt) {
463 case bltzal_op:
464 case bltzall_op:
465 if (NO_R6EMU && (insn.i_format.rs ||
466 insn.i_format.rt == bltzall_op))
467 break;
468
469 regs->regs[31] = regs->cp0_epc +
470 dec_insn.pc_inc +
471 dec_insn.next_pc_inc;
472 /* Fall through */
473 case bltzl_op:
474 if (NO_R6EMU)
475 break;
476 case bltz_op:
477 if ((long)regs->regs[insn.i_format.rs] < 0)
478 *contpc = regs->cp0_epc +
479 dec_insn.pc_inc +
480 (insn.i_format.simmediate << 2);
481 else
482 *contpc = regs->cp0_epc +
483 dec_insn.pc_inc +
484 dec_insn.next_pc_inc;
485 return 1;
486 case bgezal_op:
487 case bgezall_op:
488 if (NO_R6EMU && (insn.i_format.rs ||
489 insn.i_format.rt == bgezall_op))
490 break;
491
492 regs->regs[31] = regs->cp0_epc +
493 dec_insn.pc_inc +
494 dec_insn.next_pc_inc;
495 /* Fall through */
496 case bgezl_op:
497 if (NO_R6EMU)
498 break;
499 case bgez_op:
500 if ((long)regs->regs[insn.i_format.rs] >= 0)
501 *contpc = regs->cp0_epc +
502 dec_insn.pc_inc +
503 (insn.i_format.simmediate << 2);
504 else
505 *contpc = regs->cp0_epc +
506 dec_insn.pc_inc +
507 dec_insn.next_pc_inc;
508 return 1;
509 }
510 break;
511 case jalx_op:
512 set_isa16_mode(bit);
513 case jal_op:
514 regs->regs[31] = regs->cp0_epc +
515 dec_insn.pc_inc +
516 dec_insn.next_pc_inc;
517 /* Fall through */
518 case j_op:
519 *contpc = regs->cp0_epc + dec_insn.pc_inc;
520 *contpc >>= 28;
521 *contpc <<= 28;
522 *contpc |= (insn.j_format.target << 2);
523 /* Set microMIPS mode bit: XOR for jalx. */
524 *contpc ^= bit;
525 return 1;
526 case beql_op:
527 if (NO_R6EMU)
528 break;
529 case beq_op:
530 if (regs->regs[insn.i_format.rs] ==
531 regs->regs[insn.i_format.rt])
532 *contpc = regs->cp0_epc +
533 dec_insn.pc_inc +
534 (insn.i_format.simmediate << 2);
535 else
536 *contpc = regs->cp0_epc +
537 dec_insn.pc_inc +
538 dec_insn.next_pc_inc;
539 return 1;
540 case bnel_op:
541 if (NO_R6EMU)
542 break;
543 case bne_op:
544 if (regs->regs[insn.i_format.rs] !=
545 regs->regs[insn.i_format.rt])
546 *contpc = regs->cp0_epc +
547 dec_insn.pc_inc +
548 (insn.i_format.simmediate << 2);
549 else
550 *contpc = regs->cp0_epc +
551 dec_insn.pc_inc +
552 dec_insn.next_pc_inc;
553 return 1;
554 case blezl_op:
555 if (!insn.i_format.rt && NO_R6EMU)
556 break;
557 case blez_op:
558
559 /*
560 * Compact branches for R6 for the
561 * blez and blezl opcodes.
562 * BLEZ | rs = 0 | rt != 0 == BLEZALC
563 * BLEZ | rs = rt != 0 == BGEZALC
564 * BLEZ | rs != 0 | rt != 0 == BGEUC
565 * BLEZL | rs = 0 | rt != 0 == BLEZC
566 * BLEZL | rs = rt != 0 == BGEZC
567 * BLEZL | rs != 0 | rt != 0 == BGEC
568 *
569 * For real BLEZ{,L}, rt is always 0.
570 */
571 if (cpu_has_mips_r6 && insn.i_format.rt) {
572 if ((insn.i_format.opcode == blez_op) &&
573 ((!insn.i_format.rs && insn.i_format.rt) ||
574 (insn.i_format.rs == insn.i_format.rt)))
575 regs->regs[31] = regs->cp0_epc +
576 dec_insn.pc_inc;
577 *contpc = regs->cp0_epc + dec_insn.pc_inc +
578 dec_insn.next_pc_inc;
579
580 return 1;
581 }
582 if ((long)regs->regs[insn.i_format.rs] <= 0)
583 *contpc = regs->cp0_epc +
584 dec_insn.pc_inc +
585 (insn.i_format.simmediate << 2);
586 else
587 *contpc = regs->cp0_epc +
588 dec_insn.pc_inc +
589 dec_insn.next_pc_inc;
590 return 1;
591 case bgtzl_op:
592 if (!insn.i_format.rt && NO_R6EMU)
593 break;
594 case bgtz_op:
595 /*
596 * Compact branches for R6 for the
597 * bgtz and bgtzl opcodes.
598 * BGTZ | rs = 0 | rt != 0 == BGTZALC
599 * BGTZ | rs = rt != 0 == BLTZALC
600 * BGTZ | rs != 0 | rt != 0 == BLTUC
601 * BGTZL | rs = 0 | rt != 0 == BGTZC
602 * BGTZL | rs = rt != 0 == BLTZC
603 * BGTZL | rs != 0 | rt != 0 == BLTC
604 *
605 * *ZALC varint for BGTZ &&& rt != 0
606 * For real GTZ{,L}, rt is always 0.
607 */
608 if (cpu_has_mips_r6 && insn.i_format.rt) {
609 if ((insn.i_format.opcode == blez_op) &&
610 ((!insn.i_format.rs && insn.i_format.rt) ||
611 (insn.i_format.rs == insn.i_format.rt)))
612 regs->regs[31] = regs->cp0_epc +
613 dec_insn.pc_inc;
614 *contpc = regs->cp0_epc + dec_insn.pc_inc +
615 dec_insn.next_pc_inc;
616
617 return 1;
618 }
619
620 if ((long)regs->regs[insn.i_format.rs] > 0)
621 *contpc = regs->cp0_epc +
622 dec_insn.pc_inc +
623 (insn.i_format.simmediate << 2);
624 else
625 *contpc = regs->cp0_epc +
626 dec_insn.pc_inc +
627 dec_insn.next_pc_inc;
628 return 1;
629 case pop10_op:
630 case pop30_op:
631 if (!cpu_has_mips_r6)
632 break;
633 if (insn.i_format.rt && !insn.i_format.rs)
634 regs->regs[31] = regs->cp0_epc + 4;
635 *contpc = regs->cp0_epc + dec_insn.pc_inc +
636 dec_insn.next_pc_inc;
637
638 return 1;
639#ifdef CONFIG_CPU_CAVIUM_OCTEON
640 case lwc2_op: /* This is bbit0 on Octeon */
641 if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
642 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
643 else
644 *contpc = regs->cp0_epc + 8;
645 return 1;
646 case ldc2_op: /* This is bbit032 on Octeon */
647 if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
648 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
649 else
650 *contpc = regs->cp0_epc + 8;
651 return 1;
652 case swc2_op: /* This is bbit1 on Octeon */
653 if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
654 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
655 else
656 *contpc = regs->cp0_epc + 8;
657 return 1;
658 case sdc2_op: /* This is bbit132 on Octeon */
659 if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
660 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
661 else
662 *contpc = regs->cp0_epc + 8;
663 return 1;
664#else
665 case bc6_op:
666 /*
667 * Only valid for MIPS R6 but we can still end up
668 * here from a broken userland so just tell emulator
669 * this is not a branch and let it break later on.
670 */
671 if (!cpu_has_mips_r6)
672 break;
673 *contpc = regs->cp0_epc + dec_insn.pc_inc +
674 dec_insn.next_pc_inc;
675
676 return 1;
677 case balc6_op:
678 if (!cpu_has_mips_r6)
679 break;
680 regs->regs[31] = regs->cp0_epc + 4;
681 *contpc = regs->cp0_epc + dec_insn.pc_inc +
682 dec_insn.next_pc_inc;
683
684 return 1;
685 case pop66_op:
686 if (!cpu_has_mips_r6)
687 break;
688 *contpc = regs->cp0_epc + dec_insn.pc_inc +
689 dec_insn.next_pc_inc;
690
691 return 1;
692 case pop76_op:
693 if (!cpu_has_mips_r6)
694 break;
695 if (!insn.i_format.rs)
696 regs->regs[31] = regs->cp0_epc + 4;
697 *contpc = regs->cp0_epc + dec_insn.pc_inc +
698 dec_insn.next_pc_inc;
699
700 return 1;
701#endif
702 case cop0_op:
703 case cop1_op:
704 /* Need to check for R6 bc1nez and bc1eqz branches */
705 if (cpu_has_mips_r6 &&
706 ((insn.i_format.rs == bc1eqz_op) ||
707 (insn.i_format.rs == bc1nez_op))) {
708 bit = 0;
709 switch (insn.i_format.rs) {
710 case bc1eqz_op:
711 if (get_fpr32(¤t->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1)
712 bit = 1;
713 break;
714 case bc1nez_op:
715 if (!(get_fpr32(¤t->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1))
716 bit = 1;
717 break;
718 }
719 if (bit)
720 *contpc = regs->cp0_epc +
721 dec_insn.pc_inc +
722 (insn.i_format.simmediate << 2);
723 else
724 *contpc = regs->cp0_epc +
725 dec_insn.pc_inc +
726 dec_insn.next_pc_inc;
727
728 return 1;
729 }
730 /* R2/R6 compatible cop1 instruction. Fall through */
731 case cop2_op:
732 case cop1x_op:
733 if (insn.i_format.rs == bc_op) {
734 preempt_disable();
735 if (is_fpu_owner())
736 fcr31 = read_32bit_cp1_register(CP1_STATUS);
737 else
738 fcr31 = current->thread.fpu.fcr31;
739 preempt_enable();
740
741 bit = (insn.i_format.rt >> 2);
742 bit += (bit != 0);
743 bit += 23;
744 switch (insn.i_format.rt & 3) {
745 case 0: /* bc1f */
746 case 2: /* bc1fl */
747 if (~fcr31 & (1 << bit))
748 *contpc = regs->cp0_epc +
749 dec_insn.pc_inc +
750 (insn.i_format.simmediate << 2);
751 else
752 *contpc = regs->cp0_epc +
753 dec_insn.pc_inc +
754 dec_insn.next_pc_inc;
755 return 1;
756 case 1: /* bc1t */
757 case 3: /* bc1tl */
758 if (fcr31 & (1 << bit))
759 *contpc = regs->cp0_epc +
760 dec_insn.pc_inc +
761 (insn.i_format.simmediate << 2);
762 else
763 *contpc = regs->cp0_epc +
764 dec_insn.pc_inc +
765 dec_insn.next_pc_inc;
766 return 1;
767 }
768 }
769 break;
770 }
771 return 0;
772}
773
774/*
775 * In the Linux kernel, we support selection of FPR format on the
776 * basis of the Status.FR bit. If an FPU is not present, the FR bit
777 * is hardwired to zero, which would imply a 32-bit FPU even for
778 * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
779 * FPU emu is slow and bulky and optimizing this function offers fairly
780 * sizeable benefits so we try to be clever and make this function return
781 * a constant whenever possible, that is on 64-bit kernels without O32
782 * compatibility enabled and on 32-bit without 64-bit FPU support.
783 */
784static inline int cop1_64bit(struct pt_regs *xcp)
785{
786 if (IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_MIPS32_O32))
787 return 1;
788 else if (IS_ENABLED(CONFIG_32BIT) &&
789 !IS_ENABLED(CONFIG_MIPS_O32_FP64_SUPPORT))
790 return 0;
791
792 return !test_thread_flag(TIF_32BIT_FPREGS);
793}
794
795static inline bool hybrid_fprs(void)
796{
797 return test_thread_flag(TIF_HYBRID_FPREGS);
798}
799
800#define SIFROMREG(si, x) \
801do { \
802 if (cop1_64bit(xcp) && !hybrid_fprs()) \
803 (si) = (int)get_fpr32(&ctx->fpr[x], 0); \
804 else \
805 (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \
806} while (0)
807
808#define SITOREG(si, x) \
809do { \
810 if (cop1_64bit(xcp) && !hybrid_fprs()) { \
811 unsigned i; \
812 set_fpr32(&ctx->fpr[x], 0, si); \
813 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
814 set_fpr32(&ctx->fpr[x], i, 0); \
815 } else { \
816 set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si); \
817 } \
818} while (0)
819
820#define SIFROMHREG(si, x) ((si) = (int)get_fpr32(&ctx->fpr[x], 1))
821
822#define SITOHREG(si, x) \
823do { \
824 unsigned i; \
825 set_fpr32(&ctx->fpr[x], 1, si); \
826 for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
827 set_fpr32(&ctx->fpr[x], i, 0); \
828} while (0)
829
830#define DIFROMREG(di, x) \
831 ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0))
832
833#define DITOREG(di, x) \
834do { \
835 unsigned fpr, i; \
836 fpr = (x) & ~(cop1_64bit(xcp) == 0); \
837 set_fpr64(&ctx->fpr[fpr], 0, di); \
838 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++) \
839 set_fpr64(&ctx->fpr[fpr], i, 0); \
840} while (0)
841
842#define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
843#define SPTOREG(sp, x) SITOREG((sp).bits, x)
844#define DPFROMREG(dp, x) DIFROMREG((dp).bits, x)
845#define DPTOREG(dp, x) DITOREG((dp).bits, x)
846
847/*
848 * Emulate a CFC1 instruction.
849 */
850static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
851 mips_instruction ir)
852{
853 u32 fcr31 = ctx->fcr31;
854 u32 value = 0;
855
856 switch (MIPSInst_RD(ir)) {
857 case FPCREG_CSR:
858 value = fcr31;
859 pr_debug("%p gpr[%d]<-csr=%08x\n",
860 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
861 break;
862
863 case FPCREG_FENR:
864 if (!cpu_has_mips_r)
865 break;
866 value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
867 MIPS_FENR_FS;
868 value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM);
869 pr_debug("%p gpr[%d]<-enr=%08x\n",
870 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
871 break;
872
873 case FPCREG_FEXR:
874 if (!cpu_has_mips_r)
875 break;
876 value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
877 pr_debug("%p gpr[%d]<-exr=%08x\n",
878 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
879 break;
880
881 case FPCREG_FCCR:
882 if (!cpu_has_mips_r)
883 break;
884 value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
885 MIPS_FCCR_COND0;
886 value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
887 (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0);
888 pr_debug("%p gpr[%d]<-ccr=%08x\n",
889 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
890 break;
891
892 case FPCREG_RID:
893 value = boot_cpu_data.fpu_id;
894 break;
895
896 default:
897 break;
898 }
899
900 if (MIPSInst_RT(ir))
901 xcp->regs[MIPSInst_RT(ir)] = value;
902}
903
904/*
905 * Emulate a CTC1 instruction.
906 */
907static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
908 mips_instruction ir)
909{
910 u32 fcr31 = ctx->fcr31;
911 u32 value;
912 u32 mask;
913
914 if (MIPSInst_RT(ir) == 0)
915 value = 0;
916 else
917 value = xcp->regs[MIPSInst_RT(ir)];
918
919 switch (MIPSInst_RD(ir)) {
920 case FPCREG_CSR:
921 pr_debug("%p gpr[%d]->csr=%08x\n",
922 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
923
924 /* Preserve read-only bits. */
925 mask = boot_cpu_data.fpu_msk31;
926 fcr31 = (value & ~mask) | (fcr31 & mask);
927 break;
928
929 case FPCREG_FENR:
930 if (!cpu_has_mips_r)
931 break;
932 pr_debug("%p gpr[%d]->enr=%08x\n",
933 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
934 fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM);
935 fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
936 FPU_CSR_FS;
937 fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM);
938 break;
939
940 case FPCREG_FEXR:
941 if (!cpu_has_mips_r)
942 break;
943 pr_debug("%p gpr[%d]->exr=%08x\n",
944 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
945 fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S);
946 fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
947 break;
948
949 case FPCREG_FCCR:
950 if (!cpu_has_mips_r)
951 break;
952 pr_debug("%p gpr[%d]->ccr=%08x\n",
953 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
954 fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND);
955 fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
956 FPU_CSR_COND;
957 fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
958 FPU_CSR_CONDX;
959 break;
960
961 default:
962 break;
963 }
964
965 ctx->fcr31 = fcr31;
966}
967
968/*
969 * Emulate the single floating point instruction pointed at by EPC.
970 * Two instructions if the instruction is in a branch delay slot.
971 */
972
973static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
974 struct mm_decoded_insn dec_insn, void *__user *fault_addr)
975{
976 unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
977 unsigned int cond, cbit, bit0;
978 mips_instruction ir;
979 int likely, pc_inc;
980 union fpureg *fpr;
981 u32 __user *wva;
982 u64 __user *dva;
983 u32 wval;
984 u64 dval;
985 int sig;
986
987 /*
988 * These are giving gcc a gentle hint about what to expect in
989 * dec_inst in order to do better optimization.
990 */
991 if (!cpu_has_mmips && dec_insn.micro_mips_mode)
992 unreachable();
993
994 /* XXX NEC Vr54xx bug workaround */
995 if (delay_slot(xcp)) {
996 if (dec_insn.micro_mips_mode) {
997 if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
998 clear_delay_slot(xcp);
999 } else {
1000 if (!isBranchInstr(xcp, dec_insn, &contpc))
1001 clear_delay_slot(xcp);
1002 }
1003 }
1004
1005 if (delay_slot(xcp)) {
1006 /*
1007 * The instruction to be emulated is in a branch delay slot
1008 * which means that we have to emulate the branch instruction
1009 * BEFORE we do the cop1 instruction.
1010 *
1011 * This branch could be a COP1 branch, but in that case we
1012 * would have had a trap for that instruction, and would not
1013 * come through this route.
1014 *
1015 * Linux MIPS branch emulator operates on context, updating the
1016 * cp0_epc.
1017 */
1018 ir = dec_insn.next_insn; /* process delay slot instr */
1019 pc_inc = dec_insn.next_pc_inc;
1020 } else {
1021 ir = dec_insn.insn; /* process current instr */
1022 pc_inc = dec_insn.pc_inc;
1023 }
1024
1025 /*
1026 * Since microMIPS FPU instructios are a subset of MIPS32 FPU
1027 * instructions, we want to convert microMIPS FPU instructions
1028 * into MIPS32 instructions so that we could reuse all of the
1029 * FPU emulation code.
1030 *
1031 * NOTE: We cannot do this for branch instructions since they
1032 * are not a subset. Example: Cannot emulate a 16-bit
1033 * aligned target address with a MIPS32 instruction.
1034 */
1035 if (dec_insn.micro_mips_mode) {
1036 /*
1037 * If next instruction is a 16-bit instruction, then it
1038 * it cannot be a FPU instruction. This could happen
1039 * since we can be called for non-FPU instructions.
1040 */
1041 if ((pc_inc == 2) ||
1042 (microMIPS32_to_MIPS32((union mips_instruction *)&ir)
1043 == SIGILL))
1044 return SIGILL;
1045 }
1046
1047emul:
1048 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
1049 MIPS_FPU_EMU_INC_STATS(emulated);
1050 switch (MIPSInst_OPCODE(ir)) {
1051 case ldc1_op:
1052 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1053 MIPSInst_SIMM(ir));
1054 MIPS_FPU_EMU_INC_STATS(loads);
1055
1056 if (!access_ok(VERIFY_READ, dva, sizeof(u64))) {
1057 MIPS_FPU_EMU_INC_STATS(errors);
1058 *fault_addr = dva;
1059 return SIGBUS;
1060 }
1061 if (__get_user(dval, dva)) {
1062 MIPS_FPU_EMU_INC_STATS(errors);
1063 *fault_addr = dva;
1064 return SIGSEGV;
1065 }
1066 DITOREG(dval, MIPSInst_RT(ir));
1067 break;
1068
1069 case sdc1_op:
1070 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1071 MIPSInst_SIMM(ir));
1072 MIPS_FPU_EMU_INC_STATS(stores);
1073 DIFROMREG(dval, MIPSInst_RT(ir));
1074 if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) {
1075 MIPS_FPU_EMU_INC_STATS(errors);
1076 *fault_addr = dva;
1077 return SIGBUS;
1078 }
1079 if (__put_user(dval, dva)) {
1080 MIPS_FPU_EMU_INC_STATS(errors);
1081 *fault_addr = dva;
1082 return SIGSEGV;
1083 }
1084 break;
1085
1086 case lwc1_op:
1087 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1088 MIPSInst_SIMM(ir));
1089 MIPS_FPU_EMU_INC_STATS(loads);
1090 if (!access_ok(VERIFY_READ, wva, sizeof(u32))) {
1091 MIPS_FPU_EMU_INC_STATS(errors);
1092 *fault_addr = wva;
1093 return SIGBUS;
1094 }
1095 if (__get_user(wval, wva)) {
1096 MIPS_FPU_EMU_INC_STATS(errors);
1097 *fault_addr = wva;
1098 return SIGSEGV;
1099 }
1100 SITOREG(wval, MIPSInst_RT(ir));
1101 break;
1102
1103 case swc1_op:
1104 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1105 MIPSInst_SIMM(ir));
1106 MIPS_FPU_EMU_INC_STATS(stores);
1107 SIFROMREG(wval, MIPSInst_RT(ir));
1108 if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) {
1109 MIPS_FPU_EMU_INC_STATS(errors);
1110 *fault_addr = wva;
1111 return SIGBUS;
1112 }
1113 if (__put_user(wval, wva)) {
1114 MIPS_FPU_EMU_INC_STATS(errors);
1115 *fault_addr = wva;
1116 return SIGSEGV;
1117 }
1118 break;
1119
1120 case cop1_op:
1121 switch (MIPSInst_RS(ir)) {
1122 case dmfc_op:
1123 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1124 return SIGILL;
1125
1126 /* copregister fs -> gpr[rt] */
1127 if (MIPSInst_RT(ir) != 0) {
1128 DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1129 MIPSInst_RD(ir));
1130 }
1131 break;
1132
1133 case dmtc_op:
1134 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1135 return SIGILL;
1136
1137 /* copregister fs <- rt */
1138 DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1139 break;
1140
1141 case mfhc_op:
1142 if (!cpu_has_mips_r2_r6)
1143 goto sigill;
1144
1145 /* copregister rd -> gpr[rt] */
1146 if (MIPSInst_RT(ir) != 0) {
1147 SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
1148 MIPSInst_RD(ir));
1149 }
1150 break;
1151
1152 case mthc_op:
1153 if (!cpu_has_mips_r2_r6)
1154 goto sigill;
1155
1156 /* copregister rd <- gpr[rt] */
1157 SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1158 break;
1159
1160 case mfc_op:
1161 /* copregister rd -> gpr[rt] */
1162 if (MIPSInst_RT(ir) != 0) {
1163 SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1164 MIPSInst_RD(ir));
1165 }
1166 break;
1167
1168 case mtc_op:
1169 /* copregister rd <- rt */
1170 SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1171 break;
1172
1173 case cfc_op:
1174 /* cop control register rd -> gpr[rt] */
1175 cop1_cfc(xcp, ctx, ir);
1176 break;
1177
1178 case ctc_op:
1179 /* copregister rd <- rt */
1180 cop1_ctc(xcp, ctx, ir);
1181 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1182 return SIGFPE;
1183 }
1184 break;
1185
1186 case bc1eqz_op:
1187 case bc1nez_op:
1188 if (!cpu_has_mips_r6 || delay_slot(xcp))
1189 return SIGILL;
1190
1191 cond = likely = 0;
1192 fpr = ¤t->thread.fpu.fpr[MIPSInst_RT(ir)];
1193 bit0 = get_fpr32(fpr, 0) & 0x1;
1194 switch (MIPSInst_RS(ir)) {
1195 case bc1eqz_op:
1196 cond = bit0 == 0;
1197 break;
1198 case bc1nez_op:
1199 cond = bit0 != 0;
1200 break;
1201 }
1202 goto branch_common;
1203
1204 case bc_op:
1205 if (delay_slot(xcp))
1206 return SIGILL;
1207
1208 if (cpu_has_mips_4_5_r)
1209 cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
1210 else
1211 cbit = FPU_CSR_COND;
1212 cond = ctx->fcr31 & cbit;
1213
1214 likely = 0;
1215 switch (MIPSInst_RT(ir) & 3) {
1216 case bcfl_op:
1217 if (cpu_has_mips_2_3_4_5_r)
1218 likely = 1;
1219 /* Fall through */
1220 case bcf_op:
1221 cond = !cond;
1222 break;
1223 case bctl_op:
1224 if (cpu_has_mips_2_3_4_5_r)
1225 likely = 1;
1226 /* Fall through */
1227 case bct_op:
1228 break;
1229 }
1230branch_common:
1231 set_delay_slot(xcp);
1232 if (cond) {
1233 /*
1234 * Branch taken: emulate dslot instruction
1235 */
1236 unsigned long bcpc;
1237
1238 /*
1239 * Remember EPC at the branch to point back
1240 * at so that any delay-slot instruction
1241 * signal is not silently ignored.
1242 */
1243 bcpc = xcp->cp0_epc;
1244 xcp->cp0_epc += dec_insn.pc_inc;
1245
1246 contpc = MIPSInst_SIMM(ir);
1247 ir = dec_insn.next_insn;
1248 if (dec_insn.micro_mips_mode) {
1249 contpc = (xcp->cp0_epc + (contpc << 1));
1250
1251 /* If 16-bit instruction, not FPU. */
1252 if ((dec_insn.next_pc_inc == 2) ||
1253 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
1254
1255 /*
1256 * Since this instruction will
1257 * be put on the stack with
1258 * 32-bit words, get around
1259 * this problem by putting a
1260 * NOP16 as the second one.
1261 */
1262 if (dec_insn.next_pc_inc == 2)
1263 ir = (ir & (~0xffff)) | MM_NOP16;
1264
1265 /*
1266 * Single step the non-CP1
1267 * instruction in the dslot.
1268 */
1269 sig = mips_dsemul(xcp, ir,
1270 bcpc, contpc);
1271 if (sig < 0)
1272 break;
1273 if (sig)
1274 xcp->cp0_epc = bcpc;
1275 /*
1276 * SIGILL forces out of
1277 * the emulation loop.
1278 */
1279 return sig ? sig : SIGILL;
1280 }
1281 } else
1282 contpc = (xcp->cp0_epc + (contpc << 2));
1283
1284 switch (MIPSInst_OPCODE(ir)) {
1285 case lwc1_op:
1286 case swc1_op:
1287 goto emul;
1288
1289 case ldc1_op:
1290 case sdc1_op:
1291 if (cpu_has_mips_2_3_4_5_r)
1292 goto emul;
1293
1294 goto bc_sigill;
1295
1296 case cop1_op:
1297 goto emul;
1298
1299 case cop1x_op:
1300 if (cpu_has_mips_4_5_64_r2_r6)
1301 /* its one of ours */
1302 goto emul;
1303
1304 goto bc_sigill;
1305
1306 case spec_op:
1307 switch (MIPSInst_FUNC(ir)) {
1308 case movc_op:
1309 if (cpu_has_mips_4_5_r)
1310 goto emul;
1311
1312 goto bc_sigill;
1313 }
1314 break;
1315
1316 bc_sigill:
1317 xcp->cp0_epc = bcpc;
1318 return SIGILL;
1319 }
1320
1321 /*
1322 * Single step the non-cp1
1323 * instruction in the dslot
1324 */
1325 sig = mips_dsemul(xcp, ir, bcpc, contpc);
1326 if (sig < 0)
1327 break;
1328 if (sig)
1329 xcp->cp0_epc = bcpc;
1330 /* SIGILL forces out of the emulation loop. */
1331 return sig ? sig : SIGILL;
1332 } else if (likely) { /* branch not taken */
1333 /*
1334 * branch likely nullifies
1335 * dslot if not taken
1336 */
1337 xcp->cp0_epc += dec_insn.pc_inc;
1338 contpc += dec_insn.pc_inc;
1339 /*
1340 * else continue & execute
1341 * dslot as normal insn
1342 */
1343 }
1344 break;
1345
1346 default:
1347 if (!(MIPSInst_RS(ir) & 0x10))
1348 return SIGILL;
1349
1350 /* a real fpu computation instruction */
1351 if ((sig = fpu_emu(xcp, ctx, ir)))
1352 return sig;
1353 }
1354 break;
1355
1356 case cop1x_op:
1357 if (!cpu_has_mips_4_5_64_r2_r6)
1358 return SIGILL;
1359
1360 sig = fpux_emu(xcp, ctx, ir, fault_addr);
1361 if (sig)
1362 return sig;
1363 break;
1364
1365 case spec_op:
1366 if (!cpu_has_mips_4_5_r)
1367 return SIGILL;
1368
1369 if (MIPSInst_FUNC(ir) != movc_op)
1370 return SIGILL;
1371 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
1372 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
1373 xcp->regs[MIPSInst_RD(ir)] =
1374 xcp->regs[MIPSInst_RS(ir)];
1375 break;
1376 default:
1377sigill:
1378 return SIGILL;
1379 }
1380
1381 /* we did it !! */
1382 xcp->cp0_epc = contpc;
1383 clear_delay_slot(xcp);
1384
1385 return 0;
1386}
1387
1388/*
1389 * Conversion table from MIPS compare ops 48-63
1390 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
1391 */
1392static const unsigned char cmptab[8] = {
1393 0, /* cmp_0 (sig) cmp_sf */
1394 IEEE754_CUN, /* cmp_un (sig) cmp_ngle */
1395 IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */
1396 IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */
1397 IEEE754_CLT, /* cmp_olt (sig) cmp_lt */
1398 IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */
1399 IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */
1400 IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */
1401};
1402
1403static const unsigned char negative_cmptab[8] = {
1404 0, /* Reserved */
1405 IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ,
1406 IEEE754_CLT | IEEE754_CGT | IEEE754_CUN,
1407 IEEE754_CLT | IEEE754_CGT,
1408 /* Reserved */
1409};
1410
1411
1412/*
1413 * Additional MIPS4 instructions
1414 */
1415
1416#define DEF3OP(name, p, f1, f2, f3) \
1417static union ieee754##p fpemu_##p##_##name(union ieee754##p r, \
1418 union ieee754##p s, union ieee754##p t) \
1419{ \
1420 struct _ieee754_csr ieee754_csr_save; \
1421 s = f1(s, t); \
1422 ieee754_csr_save = ieee754_csr; \
1423 s = f2(s, r); \
1424 ieee754_csr_save.cx |= ieee754_csr.cx; \
1425 ieee754_csr_save.sx |= ieee754_csr.sx; \
1426 s = f3(s); \
1427 ieee754_csr.cx |= ieee754_csr_save.cx; \
1428 ieee754_csr.sx |= ieee754_csr_save.sx; \
1429 return s; \
1430}
1431
1432static union ieee754dp fpemu_dp_recip(union ieee754dp d)
1433{
1434 return ieee754dp_div(ieee754dp_one(0), d);
1435}
1436
1437static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
1438{
1439 return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
1440}
1441
1442static union ieee754sp fpemu_sp_recip(union ieee754sp s)
1443{
1444 return ieee754sp_div(ieee754sp_one(0), s);
1445}
1446
1447static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s)
1448{
1449 return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
1450}
1451
1452DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
1453DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
1454DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
1455DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
1456DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
1457DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
1458DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
1459DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
1460
1461static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1462 mips_instruction ir, void *__user *fault_addr)
1463{
1464 unsigned rcsr = 0; /* resulting csr */
1465
1466 MIPS_FPU_EMU_INC_STATS(cp1xops);
1467
1468 switch (MIPSInst_FMA_FFMT(ir)) {
1469 case s_fmt:{ /* 0 */
1470
1471 union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
1472 union ieee754sp fd, fr, fs, ft;
1473 u32 __user *va;
1474 u32 val;
1475
1476 switch (MIPSInst_FUNC(ir)) {
1477 case lwxc1_op:
1478 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1479 xcp->regs[MIPSInst_FT(ir)]);
1480
1481 MIPS_FPU_EMU_INC_STATS(loads);
1482 if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
1483 MIPS_FPU_EMU_INC_STATS(errors);
1484 *fault_addr = va;
1485 return SIGBUS;
1486 }
1487 if (__get_user(val, va)) {
1488 MIPS_FPU_EMU_INC_STATS(errors);
1489 *fault_addr = va;
1490 return SIGSEGV;
1491 }
1492 SITOREG(val, MIPSInst_FD(ir));
1493 break;
1494
1495 case swxc1_op:
1496 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1497 xcp->regs[MIPSInst_FT(ir)]);
1498
1499 MIPS_FPU_EMU_INC_STATS(stores);
1500
1501 SIFROMREG(val, MIPSInst_FS(ir));
1502 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
1503 MIPS_FPU_EMU_INC_STATS(errors);
1504 *fault_addr = va;
1505 return SIGBUS;
1506 }
1507 if (put_user(val, va)) {
1508 MIPS_FPU_EMU_INC_STATS(errors);
1509 *fault_addr = va;
1510 return SIGSEGV;
1511 }
1512 break;
1513
1514 case madd_s_op:
1515 handler = fpemu_sp_madd;
1516 goto scoptop;
1517 case msub_s_op:
1518 handler = fpemu_sp_msub;
1519 goto scoptop;
1520 case nmadd_s_op:
1521 handler = fpemu_sp_nmadd;
1522 goto scoptop;
1523 case nmsub_s_op:
1524 handler = fpemu_sp_nmsub;
1525 goto scoptop;
1526
1527 scoptop:
1528 SPFROMREG(fr, MIPSInst_FR(ir));
1529 SPFROMREG(fs, MIPSInst_FS(ir));
1530 SPFROMREG(ft, MIPSInst_FT(ir));
1531 fd = (*handler) (fr, fs, ft);
1532 SPTOREG(fd, MIPSInst_FD(ir));
1533
1534 copcsr:
1535 if (ieee754_cxtest(IEEE754_INEXACT)) {
1536 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1537 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1538 }
1539 if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1540 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1541 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1542 }
1543 if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1544 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1545 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1546 }
1547 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1548 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1549 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1550 }
1551
1552 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1553 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1554 /*printk ("SIGFPE: FPU csr = %08x\n",
1555 ctx->fcr31); */
1556 return SIGFPE;
1557 }
1558
1559 break;
1560
1561 default:
1562 return SIGILL;
1563 }
1564 break;
1565 }
1566
1567 case d_fmt:{ /* 1 */
1568 union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
1569 union ieee754dp fd, fr, fs, ft;
1570 u64 __user *va;
1571 u64 val;
1572
1573 switch (MIPSInst_FUNC(ir)) {
1574 case ldxc1_op:
1575 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1576 xcp->regs[MIPSInst_FT(ir)]);
1577
1578 MIPS_FPU_EMU_INC_STATS(loads);
1579 if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
1580 MIPS_FPU_EMU_INC_STATS(errors);
1581 *fault_addr = va;
1582 return SIGBUS;
1583 }
1584 if (__get_user(val, va)) {
1585 MIPS_FPU_EMU_INC_STATS(errors);
1586 *fault_addr = va;
1587 return SIGSEGV;
1588 }
1589 DITOREG(val, MIPSInst_FD(ir));
1590 break;
1591
1592 case sdxc1_op:
1593 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1594 xcp->regs[MIPSInst_FT(ir)]);
1595
1596 MIPS_FPU_EMU_INC_STATS(stores);
1597 DIFROMREG(val, MIPSInst_FS(ir));
1598 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
1599 MIPS_FPU_EMU_INC_STATS(errors);
1600 *fault_addr = va;
1601 return SIGBUS;
1602 }
1603 if (__put_user(val, va)) {
1604 MIPS_FPU_EMU_INC_STATS(errors);
1605 *fault_addr = va;
1606 return SIGSEGV;
1607 }
1608 break;
1609
1610 case madd_d_op:
1611 handler = fpemu_dp_madd;
1612 goto dcoptop;
1613 case msub_d_op:
1614 handler = fpemu_dp_msub;
1615 goto dcoptop;
1616 case nmadd_d_op:
1617 handler = fpemu_dp_nmadd;
1618 goto dcoptop;
1619 case nmsub_d_op:
1620 handler = fpemu_dp_nmsub;
1621 goto dcoptop;
1622
1623 dcoptop:
1624 DPFROMREG(fr, MIPSInst_FR(ir));
1625 DPFROMREG(fs, MIPSInst_FS(ir));
1626 DPFROMREG(ft, MIPSInst_FT(ir));
1627 fd = (*handler) (fr, fs, ft);
1628 DPTOREG(fd, MIPSInst_FD(ir));
1629 goto copcsr;
1630
1631 default:
1632 return SIGILL;
1633 }
1634 break;
1635 }
1636
1637 case 0x3:
1638 if (MIPSInst_FUNC(ir) != pfetch_op)
1639 return SIGILL;
1640
1641 /* ignore prefx operation */
1642 break;
1643
1644 default:
1645 return SIGILL;
1646 }
1647
1648 return 0;
1649}
1650
1651
1652
1653/*
1654 * Emulate a single COP1 arithmetic instruction.
1655 */
1656static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1657 mips_instruction ir)
1658{
1659 int rfmt; /* resulting format */
1660 unsigned rcsr = 0; /* resulting csr */
1661 unsigned int oldrm;
1662 unsigned int cbit;
1663 unsigned cond;
1664 union {
1665 union ieee754dp d;
1666 union ieee754sp s;
1667 int w;
1668 s64 l;
1669 } rv; /* resulting value */
1670 u64 bits;
1671
1672 MIPS_FPU_EMU_INC_STATS(cp1ops);
1673 switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
1674 case s_fmt: { /* 0 */
1675 union {
1676 union ieee754sp(*b) (union ieee754sp, union ieee754sp);
1677 union ieee754sp(*u) (union ieee754sp);
1678 } handler;
1679 union ieee754sp fd, fs, ft;
1680
1681 switch (MIPSInst_FUNC(ir)) {
1682 /* binary ops */
1683 case fadd_op:
1684 handler.b = ieee754sp_add;
1685 goto scopbop;
1686 case fsub_op:
1687 handler.b = ieee754sp_sub;
1688 goto scopbop;
1689 case fmul_op:
1690 handler.b = ieee754sp_mul;
1691 goto scopbop;
1692 case fdiv_op:
1693 handler.b = ieee754sp_div;
1694 goto scopbop;
1695
1696 /* unary ops */
1697 case fsqrt_op:
1698 if (!cpu_has_mips_2_3_4_5_r)
1699 return SIGILL;
1700
1701 handler.u = ieee754sp_sqrt;
1702 goto scopuop;
1703
1704 /*
1705 * Note that on some MIPS IV implementations such as the
1706 * R5000 and R8000 the FSQRT and FRECIP instructions do not
1707 * achieve full IEEE-754 accuracy - however this emulator does.
1708 */
1709 case frsqrt_op:
1710 if (!cpu_has_mips_4_5_64_r2_r6)
1711 return SIGILL;
1712
1713 handler.u = fpemu_sp_rsqrt;
1714 goto scopuop;
1715
1716 case frecip_op:
1717 if (!cpu_has_mips_4_5_64_r2_r6)
1718 return SIGILL;
1719
1720 handler.u = fpemu_sp_recip;
1721 goto scopuop;
1722
1723 case fmovc_op:
1724 if (!cpu_has_mips_4_5_r)
1725 return SIGILL;
1726
1727 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1728 if (((ctx->fcr31 & cond) != 0) !=
1729 ((MIPSInst_FT(ir) & 1) != 0))
1730 return 0;
1731 SPFROMREG(rv.s, MIPSInst_FS(ir));
1732 break;
1733
1734 case fmovz_op:
1735 if (!cpu_has_mips_4_5_r)
1736 return SIGILL;
1737
1738 if (xcp->regs[MIPSInst_FT(ir)] != 0)
1739 return 0;
1740 SPFROMREG(rv.s, MIPSInst_FS(ir));
1741 break;
1742
1743 case fmovn_op:
1744 if (!cpu_has_mips_4_5_r)
1745 return SIGILL;
1746
1747 if (xcp->regs[MIPSInst_FT(ir)] == 0)
1748 return 0;
1749 SPFROMREG(rv.s, MIPSInst_FS(ir));
1750 break;
1751
1752 case fseleqz_op:
1753 if (!cpu_has_mips_r6)
1754 return SIGILL;
1755
1756 SPFROMREG(rv.s, MIPSInst_FT(ir));
1757 if (rv.w & 0x1)
1758 rv.w = 0;
1759 else
1760 SPFROMREG(rv.s, MIPSInst_FS(ir));
1761 break;
1762
1763 case fselnez_op:
1764 if (!cpu_has_mips_r6)
1765 return SIGILL;
1766
1767 SPFROMREG(rv.s, MIPSInst_FT(ir));
1768 if (rv.w & 0x1)
1769 SPFROMREG(rv.s, MIPSInst_FS(ir));
1770 else
1771 rv.w = 0;
1772 break;
1773
1774 case fmaddf_op: {
1775 union ieee754sp ft, fs, fd;
1776
1777 if (!cpu_has_mips_r6)
1778 return SIGILL;
1779
1780 SPFROMREG(ft, MIPSInst_FT(ir));
1781 SPFROMREG(fs, MIPSInst_FS(ir));
1782 SPFROMREG(fd, MIPSInst_FD(ir));
1783 rv.s = ieee754sp_maddf(fd, fs, ft);
1784 break;
1785 }
1786
1787 case fmsubf_op: {
1788 union ieee754sp ft, fs, fd;
1789
1790 if (!cpu_has_mips_r6)
1791 return SIGILL;
1792
1793 SPFROMREG(ft, MIPSInst_FT(ir));
1794 SPFROMREG(fs, MIPSInst_FS(ir));
1795 SPFROMREG(fd, MIPSInst_FD(ir));
1796 rv.s = ieee754sp_msubf(fd, fs, ft);
1797 break;
1798 }
1799
1800 case frint_op: {
1801 union ieee754sp fs;
1802
1803 if (!cpu_has_mips_r6)
1804 return SIGILL;
1805
1806 SPFROMREG(fs, MIPSInst_FS(ir));
1807 rv.l = ieee754sp_tlong(fs);
1808 rv.s = ieee754sp_flong(rv.l);
1809 goto copcsr;
1810 }
1811
1812 case fclass_op: {
1813 union ieee754sp fs;
1814
1815 if (!cpu_has_mips_r6)
1816 return SIGILL;
1817
1818 SPFROMREG(fs, MIPSInst_FS(ir));
1819 rv.w = ieee754sp_2008class(fs);
1820 rfmt = w_fmt;
1821 break;
1822 }
1823
1824 case fmin_op: {
1825 union ieee754sp fs, ft;
1826
1827 if (!cpu_has_mips_r6)
1828 return SIGILL;
1829
1830 SPFROMREG(ft, MIPSInst_FT(ir));
1831 SPFROMREG(fs, MIPSInst_FS(ir));
1832 rv.s = ieee754sp_fmin(fs, ft);
1833 break;
1834 }
1835
1836 case fmina_op: {
1837 union ieee754sp fs, ft;
1838
1839 if (!cpu_has_mips_r6)
1840 return SIGILL;
1841
1842 SPFROMREG(ft, MIPSInst_FT(ir));
1843 SPFROMREG(fs, MIPSInst_FS(ir));
1844 rv.s = ieee754sp_fmina(fs, ft);
1845 break;
1846 }
1847
1848 case fmax_op: {
1849 union ieee754sp fs, ft;
1850
1851 if (!cpu_has_mips_r6)
1852 return SIGILL;
1853
1854 SPFROMREG(ft, MIPSInst_FT(ir));
1855 SPFROMREG(fs, MIPSInst_FS(ir));
1856 rv.s = ieee754sp_fmax(fs, ft);
1857 break;
1858 }
1859
1860 case fmaxa_op: {
1861 union ieee754sp fs, ft;
1862
1863 if (!cpu_has_mips_r6)
1864 return SIGILL;
1865
1866 SPFROMREG(ft, MIPSInst_FT(ir));
1867 SPFROMREG(fs, MIPSInst_FS(ir));
1868 rv.s = ieee754sp_fmaxa(fs, ft);
1869 break;
1870 }
1871
1872 case fabs_op:
1873 handler.u = ieee754sp_abs;
1874 goto scopuop;
1875
1876 case fneg_op:
1877 handler.u = ieee754sp_neg;
1878 goto scopuop;
1879
1880 case fmov_op:
1881 /* an easy one */
1882 SPFROMREG(rv.s, MIPSInst_FS(ir));
1883 goto copcsr;
1884
1885 /* binary op on handler */
1886scopbop:
1887 SPFROMREG(fs, MIPSInst_FS(ir));
1888 SPFROMREG(ft, MIPSInst_FT(ir));
1889
1890 rv.s = (*handler.b) (fs, ft);
1891 goto copcsr;
1892scopuop:
1893 SPFROMREG(fs, MIPSInst_FS(ir));
1894 rv.s = (*handler.u) (fs);
1895 goto copcsr;
1896copcsr:
1897 if (ieee754_cxtest(IEEE754_INEXACT)) {
1898 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1899 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1900 }
1901 if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1902 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1903 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1904 }
1905 if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1906 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1907 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1908 }
1909 if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) {
1910 MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv);
1911 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
1912 }
1913 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1914 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1915 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1916 }
1917 break;
1918
1919 /* unary conv ops */
1920 case fcvts_op:
1921 return SIGILL; /* not defined */
1922
1923 case fcvtd_op:
1924 SPFROMREG(fs, MIPSInst_FS(ir));
1925 rv.d = ieee754dp_fsp(fs);
1926 rfmt = d_fmt;
1927 goto copcsr;
1928
1929 case fcvtw_op:
1930 SPFROMREG(fs, MIPSInst_FS(ir));
1931 rv.w = ieee754sp_tint(fs);
1932 rfmt = w_fmt;
1933 goto copcsr;
1934
1935 case fround_op:
1936 case ftrunc_op:
1937 case fceil_op:
1938 case ffloor_op:
1939 if (!cpu_has_mips_2_3_4_5_r)
1940 return SIGILL;
1941
1942 oldrm = ieee754_csr.rm;
1943 SPFROMREG(fs, MIPSInst_FS(ir));
1944 ieee754_csr.rm = MIPSInst_FUNC(ir);
1945 rv.w = ieee754sp_tint(fs);
1946 ieee754_csr.rm = oldrm;
1947 rfmt = w_fmt;
1948 goto copcsr;
1949
1950 case fsel_op:
1951 if (!cpu_has_mips_r6)
1952 return SIGILL;
1953
1954 SPFROMREG(fd, MIPSInst_FD(ir));
1955 if (fd.bits & 0x1)
1956 SPFROMREG(rv.s, MIPSInst_FT(ir));
1957 else
1958 SPFROMREG(rv.s, MIPSInst_FS(ir));
1959 break;
1960
1961 case fcvtl_op:
1962 if (!cpu_has_mips_3_4_5_64_r2_r6)
1963 return SIGILL;
1964
1965 SPFROMREG(fs, MIPSInst_FS(ir));
1966 rv.l = ieee754sp_tlong(fs);
1967 rfmt = l_fmt;
1968 goto copcsr;
1969
1970 case froundl_op:
1971 case ftruncl_op:
1972 case fceill_op:
1973 case ffloorl_op:
1974 if (!cpu_has_mips_3_4_5_64_r2_r6)
1975 return SIGILL;
1976
1977 oldrm = ieee754_csr.rm;
1978 SPFROMREG(fs, MIPSInst_FS(ir));
1979 ieee754_csr.rm = MIPSInst_FUNC(ir);
1980 rv.l = ieee754sp_tlong(fs);
1981 ieee754_csr.rm = oldrm;
1982 rfmt = l_fmt;
1983 goto copcsr;
1984
1985 default:
1986 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
1987 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1988 union ieee754sp fs, ft;
1989
1990 SPFROMREG(fs, MIPSInst_FS(ir));
1991 SPFROMREG(ft, MIPSInst_FT(ir));
1992 rv.w = ieee754sp_cmp(fs, ft,
1993 cmptab[cmpop & 0x7], cmpop & 0x8);
1994 rfmt = -1;
1995 if ((cmpop & 0x8) && ieee754_cxtest
1996 (IEEE754_INVALID_OPERATION))
1997 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1998 else
1999 goto copcsr;
2000
2001 } else
2002 return SIGILL;
2003 break;
2004 }
2005 break;
2006 }
2007
2008 case d_fmt: {
2009 union ieee754dp fd, fs, ft;
2010 union {
2011 union ieee754dp(*b) (union ieee754dp, union ieee754dp);
2012 union ieee754dp(*u) (union ieee754dp);
2013 } handler;
2014
2015 switch (MIPSInst_FUNC(ir)) {
2016 /* binary ops */
2017 case fadd_op:
2018 handler.b = ieee754dp_add;
2019 goto dcopbop;
2020 case fsub_op:
2021 handler.b = ieee754dp_sub;
2022 goto dcopbop;
2023 case fmul_op:
2024 handler.b = ieee754dp_mul;
2025 goto dcopbop;
2026 case fdiv_op:
2027 handler.b = ieee754dp_div;
2028 goto dcopbop;
2029
2030 /* unary ops */
2031 case fsqrt_op:
2032 if (!cpu_has_mips_2_3_4_5_r)
2033 return SIGILL;
2034
2035 handler.u = ieee754dp_sqrt;
2036 goto dcopuop;
2037 /*
2038 * Note that on some MIPS IV implementations such as the
2039 * R5000 and R8000 the FSQRT and FRECIP instructions do not
2040 * achieve full IEEE-754 accuracy - however this emulator does.
2041 */
2042 case frsqrt_op:
2043 if (!cpu_has_mips_4_5_64_r2_r6)
2044 return SIGILL;
2045
2046 handler.u = fpemu_dp_rsqrt;
2047 goto dcopuop;
2048 case frecip_op:
2049 if (!cpu_has_mips_4_5_64_r2_r6)
2050 return SIGILL;
2051
2052 handler.u = fpemu_dp_recip;
2053 goto dcopuop;
2054 case fmovc_op:
2055 if (!cpu_has_mips_4_5_r)
2056 return SIGILL;
2057
2058 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
2059 if (((ctx->fcr31 & cond) != 0) !=
2060 ((MIPSInst_FT(ir) & 1) != 0))
2061 return 0;
2062 DPFROMREG(rv.d, MIPSInst_FS(ir));
2063 break;
2064 case fmovz_op:
2065 if (!cpu_has_mips_4_5_r)
2066 return SIGILL;
2067
2068 if (xcp->regs[MIPSInst_FT(ir)] != 0)
2069 return 0;
2070 DPFROMREG(rv.d, MIPSInst_FS(ir));
2071 break;
2072 case fmovn_op:
2073 if (!cpu_has_mips_4_5_r)
2074 return SIGILL;
2075
2076 if (xcp->regs[MIPSInst_FT(ir)] == 0)
2077 return 0;
2078 DPFROMREG(rv.d, MIPSInst_FS(ir));
2079 break;
2080
2081 case fseleqz_op:
2082 if (!cpu_has_mips_r6)
2083 return SIGILL;
2084
2085 DPFROMREG(rv.d, MIPSInst_FT(ir));
2086 if (rv.l & 0x1)
2087 rv.l = 0;
2088 else
2089 DPFROMREG(rv.d, MIPSInst_FS(ir));
2090 break;
2091
2092 case fselnez_op:
2093 if (!cpu_has_mips_r6)
2094 return SIGILL;
2095
2096 DPFROMREG(rv.d, MIPSInst_FT(ir));
2097 if (rv.l & 0x1)
2098 DPFROMREG(rv.d, MIPSInst_FS(ir));
2099 else
2100 rv.l = 0;
2101 break;
2102
2103 case fmaddf_op: {
2104 union ieee754dp ft, fs, fd;
2105
2106 if (!cpu_has_mips_r6)
2107 return SIGILL;
2108
2109 DPFROMREG(ft, MIPSInst_FT(ir));
2110 DPFROMREG(fs, MIPSInst_FS(ir));
2111 DPFROMREG(fd, MIPSInst_FD(ir));
2112 rv.d = ieee754dp_maddf(fd, fs, ft);
2113 break;
2114 }
2115
2116 case fmsubf_op: {
2117 union ieee754dp ft, fs, fd;
2118
2119 if (!cpu_has_mips_r6)
2120 return SIGILL;
2121
2122 DPFROMREG(ft, MIPSInst_FT(ir));
2123 DPFROMREG(fs, MIPSInst_FS(ir));
2124 DPFROMREG(fd, MIPSInst_FD(ir));
2125 rv.d = ieee754dp_msubf(fd, fs, ft);
2126 break;
2127 }
2128
2129 case frint_op: {
2130 union ieee754dp fs;
2131
2132 if (!cpu_has_mips_r6)
2133 return SIGILL;
2134
2135 DPFROMREG(fs, MIPSInst_FS(ir));
2136 rv.l = ieee754dp_tlong(fs);
2137 rv.d = ieee754dp_flong(rv.l);
2138 goto copcsr;
2139 }
2140
2141 case fclass_op: {
2142 union ieee754dp fs;
2143
2144 if (!cpu_has_mips_r6)
2145 return SIGILL;
2146
2147 DPFROMREG(fs, MIPSInst_FS(ir));
2148 rv.w = ieee754dp_2008class(fs);
2149 rfmt = w_fmt;
2150 break;
2151 }
2152
2153 case fmin_op: {
2154 union ieee754dp fs, ft;
2155
2156 if (!cpu_has_mips_r6)
2157 return SIGILL;
2158
2159 DPFROMREG(ft, MIPSInst_FT(ir));
2160 DPFROMREG(fs, MIPSInst_FS(ir));
2161 rv.d = ieee754dp_fmin(fs, ft);
2162 break;
2163 }
2164
2165 case fmina_op: {
2166 union ieee754dp fs, ft;
2167
2168 if (!cpu_has_mips_r6)
2169 return SIGILL;
2170
2171 DPFROMREG(ft, MIPSInst_FT(ir));
2172 DPFROMREG(fs, MIPSInst_FS(ir));
2173 rv.d = ieee754dp_fmina(fs, ft);
2174 break;
2175 }
2176
2177 case fmax_op: {
2178 union ieee754dp fs, ft;
2179
2180 if (!cpu_has_mips_r6)
2181 return SIGILL;
2182
2183 DPFROMREG(ft, MIPSInst_FT(ir));
2184 DPFROMREG(fs, MIPSInst_FS(ir));
2185 rv.d = ieee754dp_fmax(fs, ft);
2186 break;
2187 }
2188
2189 case fmaxa_op: {
2190 union ieee754dp fs, ft;
2191
2192 if (!cpu_has_mips_r6)
2193 return SIGILL;
2194
2195 DPFROMREG(ft, MIPSInst_FT(ir));
2196 DPFROMREG(fs, MIPSInst_FS(ir));
2197 rv.d = ieee754dp_fmaxa(fs, ft);
2198 break;
2199 }
2200
2201 case fabs_op:
2202 handler.u = ieee754dp_abs;
2203 goto dcopuop;
2204
2205 case fneg_op:
2206 handler.u = ieee754dp_neg;
2207 goto dcopuop;
2208
2209 case fmov_op:
2210 /* an easy one */
2211 DPFROMREG(rv.d, MIPSInst_FS(ir));
2212 goto copcsr;
2213
2214 /* binary op on handler */
2215dcopbop:
2216 DPFROMREG(fs, MIPSInst_FS(ir));
2217 DPFROMREG(ft, MIPSInst_FT(ir));
2218
2219 rv.d = (*handler.b) (fs, ft);
2220 goto copcsr;
2221dcopuop:
2222 DPFROMREG(fs, MIPSInst_FS(ir));
2223 rv.d = (*handler.u) (fs);
2224 goto copcsr;
2225
2226 /*
2227 * unary conv ops
2228 */
2229 case fcvts_op:
2230 DPFROMREG(fs, MIPSInst_FS(ir));
2231 rv.s = ieee754sp_fdp(fs);
2232 rfmt = s_fmt;
2233 goto copcsr;
2234
2235 case fcvtd_op:
2236 return SIGILL; /* not defined */
2237
2238 case fcvtw_op:
2239 DPFROMREG(fs, MIPSInst_FS(ir));
2240 rv.w = ieee754dp_tint(fs); /* wrong */
2241 rfmt = w_fmt;
2242 goto copcsr;
2243
2244 case fround_op:
2245 case ftrunc_op:
2246 case fceil_op:
2247 case ffloor_op:
2248 if (!cpu_has_mips_2_3_4_5_r)
2249 return SIGILL;
2250
2251 oldrm = ieee754_csr.rm;
2252 DPFROMREG(fs, MIPSInst_FS(ir));
2253 ieee754_csr.rm = MIPSInst_FUNC(ir);
2254 rv.w = ieee754dp_tint(fs);
2255 ieee754_csr.rm = oldrm;
2256 rfmt = w_fmt;
2257 goto copcsr;
2258
2259 case fsel_op:
2260 if (!cpu_has_mips_r6)
2261 return SIGILL;
2262
2263 DPFROMREG(fd, MIPSInst_FD(ir));
2264 if (fd.bits & 0x1)
2265 DPFROMREG(rv.d, MIPSInst_FT(ir));
2266 else
2267 DPFROMREG(rv.d, MIPSInst_FS(ir));
2268 break;
2269
2270 case fcvtl_op:
2271 if (!cpu_has_mips_3_4_5_64_r2_r6)
2272 return SIGILL;
2273
2274 DPFROMREG(fs, MIPSInst_FS(ir));
2275 rv.l = ieee754dp_tlong(fs);
2276 rfmt = l_fmt;
2277 goto copcsr;
2278
2279 case froundl_op:
2280 case ftruncl_op:
2281 case fceill_op:
2282 case ffloorl_op:
2283 if (!cpu_has_mips_3_4_5_64_r2_r6)
2284 return SIGILL;
2285
2286 oldrm = ieee754_csr.rm;
2287 DPFROMREG(fs, MIPSInst_FS(ir));
2288 ieee754_csr.rm = MIPSInst_FUNC(ir);
2289 rv.l = ieee754dp_tlong(fs);
2290 ieee754_csr.rm = oldrm;
2291 rfmt = l_fmt;
2292 goto copcsr;
2293
2294 default:
2295 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2296 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2297 union ieee754dp fs, ft;
2298
2299 DPFROMREG(fs, MIPSInst_FS(ir));
2300 DPFROMREG(ft, MIPSInst_FT(ir));
2301 rv.w = ieee754dp_cmp(fs, ft,
2302 cmptab[cmpop & 0x7], cmpop & 0x8);
2303 rfmt = -1;
2304 if ((cmpop & 0x8)
2305 &&
2306 ieee754_cxtest
2307 (IEEE754_INVALID_OPERATION))
2308 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2309 else
2310 goto copcsr;
2311
2312 }
2313 else {
2314 return SIGILL;
2315 }
2316 break;
2317 }
2318 break;
2319 }
2320
2321 case w_fmt: {
2322 union ieee754dp fs;
2323
2324 switch (MIPSInst_FUNC(ir)) {
2325 case fcvts_op:
2326 /* convert word to single precision real */
2327 SPFROMREG(fs, MIPSInst_FS(ir));
2328 rv.s = ieee754sp_fint(fs.bits);
2329 rfmt = s_fmt;
2330 goto copcsr;
2331 case fcvtd_op:
2332 /* convert word to double precision real */
2333 SPFROMREG(fs, MIPSInst_FS(ir));
2334 rv.d = ieee754dp_fint(fs.bits);
2335 rfmt = d_fmt;
2336 goto copcsr;
2337 default: {
2338 /* Emulating the new CMP.condn.fmt R6 instruction */
2339#define CMPOP_MASK 0x7
2340#define SIGN_BIT (0x1 << 3)
2341#define PREDICATE_BIT (0x1 << 4)
2342
2343 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2344 int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2345 union ieee754sp fs, ft;
2346
2347 /* This is an R6 only instruction */
2348 if (!cpu_has_mips_r6 ||
2349 (MIPSInst_FUNC(ir) & 0x20))
2350 return SIGILL;
2351
2352 /* fmt is w_fmt for single precision so fix it */
2353 rfmt = s_fmt;
2354 /* default to false */
2355 rv.w = 0;
2356
2357 /* CMP.condn.S */
2358 SPFROMREG(fs, MIPSInst_FS(ir));
2359 SPFROMREG(ft, MIPSInst_FT(ir));
2360
2361 /* positive predicates */
2362 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2363 if (ieee754sp_cmp(fs, ft, cmptab[cmpop],
2364 sig))
2365 rv.w = -1; /* true, all 1s */
2366 if ((sig) &&
2367 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2368 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2369 else
2370 goto copcsr;
2371 } else {
2372 /* negative predicates */
2373 switch (cmpop) {
2374 case 1:
2375 case 2:
2376 case 3:
2377 if (ieee754sp_cmp(fs, ft,
2378 negative_cmptab[cmpop],
2379 sig))
2380 rv.w = -1; /* true, all 1s */
2381 if (sig &&
2382 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2383 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2384 else
2385 goto copcsr;
2386 break;
2387 default:
2388 /* Reserved R6 ops */
2389 pr_err("Reserved MIPS R6 CMP.condn.S operation\n");
2390 return SIGILL;
2391 }
2392 }
2393 break;
2394 }
2395 }
2396 }
2397
2398 case l_fmt:
2399
2400 if (!cpu_has_mips_3_4_5_64_r2_r6)
2401 return SIGILL;
2402
2403 DIFROMREG(bits, MIPSInst_FS(ir));
2404
2405 switch (MIPSInst_FUNC(ir)) {
2406 case fcvts_op:
2407 /* convert long to single precision real */
2408 rv.s = ieee754sp_flong(bits);
2409 rfmt = s_fmt;
2410 goto copcsr;
2411 case fcvtd_op:
2412 /* convert long to double precision real */
2413 rv.d = ieee754dp_flong(bits);
2414 rfmt = d_fmt;
2415 goto copcsr;
2416 default: {
2417 /* Emulating the new CMP.condn.fmt R6 instruction */
2418 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2419 int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2420 union ieee754dp fs, ft;
2421
2422 if (!cpu_has_mips_r6 ||
2423 (MIPSInst_FUNC(ir) & 0x20))
2424 return SIGILL;
2425
2426 /* fmt is l_fmt for double precision so fix it */
2427 rfmt = d_fmt;
2428 /* default to false */
2429 rv.l = 0;
2430
2431 /* CMP.condn.D */
2432 DPFROMREG(fs, MIPSInst_FS(ir));
2433 DPFROMREG(ft, MIPSInst_FT(ir));
2434
2435 /* positive predicates */
2436 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2437 if (ieee754dp_cmp(fs, ft,
2438 cmptab[cmpop], sig))
2439 rv.l = -1LL; /* true, all 1s */
2440 if (sig &&
2441 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2442 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2443 else
2444 goto copcsr;
2445 } else {
2446 /* negative predicates */
2447 switch (cmpop) {
2448 case 1:
2449 case 2:
2450 case 3:
2451 if (ieee754dp_cmp(fs, ft,
2452 negative_cmptab[cmpop],
2453 sig))
2454 rv.l = -1LL; /* true, all 1s */
2455 if (sig &&
2456 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2457 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2458 else
2459 goto copcsr;
2460 break;
2461 default:
2462 /* Reserved R6 ops */
2463 pr_err("Reserved MIPS R6 CMP.condn.D operation\n");
2464 return SIGILL;
2465 }
2466 }
2467 break;
2468 }
2469 }
2470 default:
2471 return SIGILL;
2472 }
2473
2474 /*
2475 * Update the fpu CSR register for this operation.
2476 * If an exception is required, generate a tidy SIGFPE exception,
2477 * without updating the result register.
2478 * Note: cause exception bits do not accumulate, they are rewritten
2479 * for each op; only the flag/sticky bits accumulate.
2480 */
2481 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
2482 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
2483 /*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */
2484 return SIGFPE;
2485 }
2486
2487 /*
2488 * Now we can safely write the result back to the register file.
2489 */
2490 switch (rfmt) {
2491 case -1:
2492
2493 if (cpu_has_mips_4_5_r)
2494 cbit = fpucondbit[MIPSInst_FD(ir) >> 2];
2495 else
2496 cbit = FPU_CSR_COND;
2497 if (rv.w)
2498 ctx->fcr31 |= cbit;
2499 else
2500 ctx->fcr31 &= ~cbit;
2501 break;
2502
2503 case d_fmt:
2504 DPTOREG(rv.d, MIPSInst_FD(ir));
2505 break;
2506 case s_fmt:
2507 SPTOREG(rv.s, MIPSInst_FD(ir));
2508 break;
2509 case w_fmt:
2510 SITOREG(rv.w, MIPSInst_FD(ir));
2511 break;
2512 case l_fmt:
2513 if (!cpu_has_mips_3_4_5_64_r2_r6)
2514 return SIGILL;
2515
2516 DITOREG(rv.l, MIPSInst_FD(ir));
2517 break;
2518 default:
2519 return SIGILL;
2520 }
2521
2522 return 0;
2523}
2524
2525int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
2526 int has_fpu, void *__user *fault_addr)
2527{
2528 unsigned long oldepc, prevepc;
2529 struct mm_decoded_insn dec_insn;
2530 u16 instr[4];
2531 u16 *instr_ptr;
2532 int sig = 0;
2533
2534 oldepc = xcp->cp0_epc;
2535 do {
2536 prevepc = xcp->cp0_epc;
2537
2538 if (get_isa16_mode(prevepc) && cpu_has_mmips) {
2539 /*
2540 * Get next 2 microMIPS instructions and convert them
2541 * into 32-bit instructions.
2542 */
2543 if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
2544 (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
2545 (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
2546 (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
2547 MIPS_FPU_EMU_INC_STATS(errors);
2548 return SIGBUS;
2549 }
2550 instr_ptr = instr;
2551
2552 /* Get first instruction. */
2553 if (mm_insn_16bit(*instr_ptr)) {
2554 /* Duplicate the half-word. */
2555 dec_insn.insn = (*instr_ptr << 16) |
2556 (*instr_ptr);
2557 /* 16-bit instruction. */
2558 dec_insn.pc_inc = 2;
2559 instr_ptr += 1;
2560 } else {
2561 dec_insn.insn = (*instr_ptr << 16) |
2562 *(instr_ptr+1);
2563 /* 32-bit instruction. */
2564 dec_insn.pc_inc = 4;
2565 instr_ptr += 2;
2566 }
2567 /* Get second instruction. */
2568 if (mm_insn_16bit(*instr_ptr)) {
2569 /* Duplicate the half-word. */
2570 dec_insn.next_insn = (*instr_ptr << 16) |
2571 (*instr_ptr);
2572 /* 16-bit instruction. */
2573 dec_insn.next_pc_inc = 2;
2574 } else {
2575 dec_insn.next_insn = (*instr_ptr << 16) |
2576 *(instr_ptr+1);
2577 /* 32-bit instruction. */
2578 dec_insn.next_pc_inc = 4;
2579 }
2580 dec_insn.micro_mips_mode = 1;
2581 } else {
2582 if ((get_user(dec_insn.insn,
2583 (mips_instruction __user *) xcp->cp0_epc)) ||
2584 (get_user(dec_insn.next_insn,
2585 (mips_instruction __user *)(xcp->cp0_epc+4)))) {
2586 MIPS_FPU_EMU_INC_STATS(errors);
2587 return SIGBUS;
2588 }
2589 dec_insn.pc_inc = 4;
2590 dec_insn.next_pc_inc = 4;
2591 dec_insn.micro_mips_mode = 0;
2592 }
2593
2594 if ((dec_insn.insn == 0) ||
2595 ((dec_insn.pc_inc == 2) &&
2596 ((dec_insn.insn & 0xffff) == MM_NOP16)))
2597 xcp->cp0_epc += dec_insn.pc_inc; /* Skip NOPs */
2598 else {
2599 /*
2600 * The 'ieee754_csr' is an alias of ctx->fcr31.
2601 * No need to copy ctx->fcr31 to ieee754_csr.
2602 */
2603 sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
2604 }
2605
2606 if (has_fpu)
2607 break;
2608 if (sig)
2609 break;
2610
2611 cond_resched();
2612 } while (xcp->cp0_epc > prevepc);
2613
2614 /* SIGILL indicates a non-fpu instruction */
2615 if (sig == SIGILL && xcp->cp0_epc != oldepc)
2616 /* but if EPC has advanced, then ignore it */
2617 sig = 0;
2618
2619 return sig;
2620}