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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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator
4 *
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd.
7 *
8 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
9 * Copyright (C) 2000 MIPS Technologies, Inc.
10 *
11 * A complete emulator for MIPS coprocessor 1 instructions. This is
12 * required for #float(switch) or #float(trap), where it catches all
13 * COP1 instructions via the "CoProcessor Unusable" exception.
14 *
15 * More surprisingly it is also required for #float(ieee), to help out
16 * the hardware FPU at the boundaries of the IEEE-754 representation
17 * (denormalised values, infinities, underflow, etc). It is made
18 * quite nasty because emulation of some non-COP1 instructions is
19 * required, e.g. in branch delay slots.
20 *
21 * Note if you know that you won't have an FPU, then you'll get much
22 * better performance by compiling with -msoft-float!
23 */
24#include <linux/sched.h>
25#include <linux/debugfs.h>
26#include <linux/percpu-defs.h>
27#include <linux/perf_event.h>
28
29#include <asm/branch.h>
30#include <asm/inst.h>
31#include <asm/ptrace.h>
32#include <asm/signal.h>
33#include <linux/uaccess.h>
34
35#include <asm/cpu-info.h>
36#include <asm/processor.h>
37#include <asm/fpu_emulator.h>
38#include <asm/fpu.h>
39#include <asm/mips-r2-to-r6-emul.h>
40
41#include "ieee754.h"
42
43/* Function which emulates a floating point instruction. */
44
45static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
46 mips_instruction);
47
48static int fpux_emu(struct pt_regs *,
49 struct mips_fpu_struct *, mips_instruction, void __user **);
50
51/* Control registers */
52
53#define FPCREG_RID 0 /* $0 = revision id */
54#define FPCREG_FCCR 25 /* $25 = fccr */
55#define FPCREG_FEXR 26 /* $26 = fexr */
56#define FPCREG_FENR 28 /* $28 = fenr */
57#define FPCREG_CSR 31 /* $31 = csr */
58
59/* convert condition code register number to csr bit */
60const unsigned int fpucondbit[8] = {
61 FPU_CSR_COND,
62 FPU_CSR_COND1,
63 FPU_CSR_COND2,
64 FPU_CSR_COND3,
65 FPU_CSR_COND4,
66 FPU_CSR_COND5,
67 FPU_CSR_COND6,
68 FPU_CSR_COND7
69};
70
71/* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
72static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
73static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
74static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
75static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
76
77/*
78 * This functions translates a 32-bit microMIPS instruction
79 * into a 32-bit MIPS32 instruction. Returns 0 on success
80 * and SIGILL otherwise.
81 */
82static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
83{
84 union mips_instruction insn = *insn_ptr;
85 union mips_instruction mips32_insn = insn;
86 int func, fmt, op;
87
88 switch (insn.mm_i_format.opcode) {
89 case mm_ldc132_op:
90 mips32_insn.mm_i_format.opcode = ldc1_op;
91 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
92 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
93 break;
94 case mm_lwc132_op:
95 mips32_insn.mm_i_format.opcode = lwc1_op;
96 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
97 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
98 break;
99 case mm_sdc132_op:
100 mips32_insn.mm_i_format.opcode = sdc1_op;
101 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
102 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
103 break;
104 case mm_swc132_op:
105 mips32_insn.mm_i_format.opcode = swc1_op;
106 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
107 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
108 break;
109 case mm_pool32i_op:
110 /* NOTE: offset is << by 1 if in microMIPS mode. */
111 if ((insn.mm_i_format.rt == mm_bc1f_op) ||
112 (insn.mm_i_format.rt == mm_bc1t_op)) {
113 mips32_insn.fb_format.opcode = cop1_op;
114 mips32_insn.fb_format.bc = bc_op;
115 mips32_insn.fb_format.flag =
116 (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
117 } else
118 return SIGILL;
119 break;
120 case mm_pool32f_op:
121 switch (insn.mm_fp0_format.func) {
122 case mm_32f_01_op:
123 case mm_32f_11_op:
124 case mm_32f_02_op:
125 case mm_32f_12_op:
126 case mm_32f_41_op:
127 case mm_32f_51_op:
128 case mm_32f_42_op:
129 case mm_32f_52_op:
130 op = insn.mm_fp0_format.func;
131 if (op == mm_32f_01_op)
132 func = madd_s_op;
133 else if (op == mm_32f_11_op)
134 func = madd_d_op;
135 else if (op == mm_32f_02_op)
136 func = nmadd_s_op;
137 else if (op == mm_32f_12_op)
138 func = nmadd_d_op;
139 else if (op == mm_32f_41_op)
140 func = msub_s_op;
141 else if (op == mm_32f_51_op)
142 func = msub_d_op;
143 else if (op == mm_32f_42_op)
144 func = nmsub_s_op;
145 else
146 func = nmsub_d_op;
147 mips32_insn.fp6_format.opcode = cop1x_op;
148 mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
149 mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
150 mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
151 mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
152 mips32_insn.fp6_format.func = func;
153 break;
154 case mm_32f_10_op:
155 func = -1; /* Invalid */
156 op = insn.mm_fp5_format.op & 0x7;
157 if (op == mm_ldxc1_op)
158 func = ldxc1_op;
159 else if (op == mm_sdxc1_op)
160 func = sdxc1_op;
161 else if (op == mm_lwxc1_op)
162 func = lwxc1_op;
163 else if (op == mm_swxc1_op)
164 func = swxc1_op;
165
166 if (func != -1) {
167 mips32_insn.r_format.opcode = cop1x_op;
168 mips32_insn.r_format.rs =
169 insn.mm_fp5_format.base;
170 mips32_insn.r_format.rt =
171 insn.mm_fp5_format.index;
172 mips32_insn.r_format.rd = 0;
173 mips32_insn.r_format.re = insn.mm_fp5_format.fd;
174 mips32_insn.r_format.func = func;
175 } else
176 return SIGILL;
177 break;
178 case mm_32f_40_op:
179 op = -1; /* Invalid */
180 if (insn.mm_fp2_format.op == mm_fmovt_op)
181 op = 1;
182 else if (insn.mm_fp2_format.op == mm_fmovf_op)
183 op = 0;
184 if (op != -1) {
185 mips32_insn.fp0_format.opcode = cop1_op;
186 mips32_insn.fp0_format.fmt =
187 sdps_format[insn.mm_fp2_format.fmt];
188 mips32_insn.fp0_format.ft =
189 (insn.mm_fp2_format.cc<<2) + op;
190 mips32_insn.fp0_format.fs =
191 insn.mm_fp2_format.fs;
192 mips32_insn.fp0_format.fd =
193 insn.mm_fp2_format.fd;
194 mips32_insn.fp0_format.func = fmovc_op;
195 } else
196 return SIGILL;
197 break;
198 case mm_32f_60_op:
199 func = -1; /* Invalid */
200 if (insn.mm_fp0_format.op == mm_fadd_op)
201 func = fadd_op;
202 else if (insn.mm_fp0_format.op == mm_fsub_op)
203 func = fsub_op;
204 else if (insn.mm_fp0_format.op == mm_fmul_op)
205 func = fmul_op;
206 else if (insn.mm_fp0_format.op == mm_fdiv_op)
207 func = fdiv_op;
208 if (func != -1) {
209 mips32_insn.fp0_format.opcode = cop1_op;
210 mips32_insn.fp0_format.fmt =
211 sdps_format[insn.mm_fp0_format.fmt];
212 mips32_insn.fp0_format.ft =
213 insn.mm_fp0_format.ft;
214 mips32_insn.fp0_format.fs =
215 insn.mm_fp0_format.fs;
216 mips32_insn.fp0_format.fd =
217 insn.mm_fp0_format.fd;
218 mips32_insn.fp0_format.func = func;
219 } else
220 return SIGILL;
221 break;
222 case mm_32f_70_op:
223 func = -1; /* Invalid */
224 if (insn.mm_fp0_format.op == mm_fmovn_op)
225 func = fmovn_op;
226 else if (insn.mm_fp0_format.op == mm_fmovz_op)
227 func = fmovz_op;
228 if (func != -1) {
229 mips32_insn.fp0_format.opcode = cop1_op;
230 mips32_insn.fp0_format.fmt =
231 sdps_format[insn.mm_fp0_format.fmt];
232 mips32_insn.fp0_format.ft =
233 insn.mm_fp0_format.ft;
234 mips32_insn.fp0_format.fs =
235 insn.mm_fp0_format.fs;
236 mips32_insn.fp0_format.fd =
237 insn.mm_fp0_format.fd;
238 mips32_insn.fp0_format.func = func;
239 } else
240 return SIGILL;
241 break;
242 case mm_32f_73_op: /* POOL32FXF */
243 switch (insn.mm_fp1_format.op) {
244 case mm_movf0_op:
245 case mm_movf1_op:
246 case mm_movt0_op:
247 case mm_movt1_op:
248 if ((insn.mm_fp1_format.op & 0x7f) ==
249 mm_movf0_op)
250 op = 0;
251 else
252 op = 1;
253 mips32_insn.r_format.opcode = spec_op;
254 mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
255 mips32_insn.r_format.rt =
256 (insn.mm_fp4_format.cc << 2) + op;
257 mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
258 mips32_insn.r_format.re = 0;
259 mips32_insn.r_format.func = movc_op;
260 break;
261 case mm_fcvtd0_op:
262 case mm_fcvtd1_op:
263 case mm_fcvts0_op:
264 case mm_fcvts1_op:
265 if ((insn.mm_fp1_format.op & 0x7f) ==
266 mm_fcvtd0_op) {
267 func = fcvtd_op;
268 fmt = swl_format[insn.mm_fp3_format.fmt];
269 } else {
270 func = fcvts_op;
271 fmt = dwl_format[insn.mm_fp3_format.fmt];
272 }
273 mips32_insn.fp0_format.opcode = cop1_op;
274 mips32_insn.fp0_format.fmt = fmt;
275 mips32_insn.fp0_format.ft = 0;
276 mips32_insn.fp0_format.fs =
277 insn.mm_fp3_format.fs;
278 mips32_insn.fp0_format.fd =
279 insn.mm_fp3_format.rt;
280 mips32_insn.fp0_format.func = func;
281 break;
282 case mm_fmov0_op:
283 case mm_fmov1_op:
284 case mm_fabs0_op:
285 case mm_fabs1_op:
286 case mm_fneg0_op:
287 case mm_fneg1_op:
288 if ((insn.mm_fp1_format.op & 0x7f) ==
289 mm_fmov0_op)
290 func = fmov_op;
291 else if ((insn.mm_fp1_format.op & 0x7f) ==
292 mm_fabs0_op)
293 func = fabs_op;
294 else
295 func = fneg_op;
296 mips32_insn.fp0_format.opcode = cop1_op;
297 mips32_insn.fp0_format.fmt =
298 sdps_format[insn.mm_fp3_format.fmt];
299 mips32_insn.fp0_format.ft = 0;
300 mips32_insn.fp0_format.fs =
301 insn.mm_fp3_format.fs;
302 mips32_insn.fp0_format.fd =
303 insn.mm_fp3_format.rt;
304 mips32_insn.fp0_format.func = func;
305 break;
306 case mm_ffloorl_op:
307 case mm_ffloorw_op:
308 case mm_fceill_op:
309 case mm_fceilw_op:
310 case mm_ftruncl_op:
311 case mm_ftruncw_op:
312 case mm_froundl_op:
313 case mm_froundw_op:
314 case mm_fcvtl_op:
315 case mm_fcvtw_op:
316 if (insn.mm_fp1_format.op == mm_ffloorl_op)
317 func = ffloorl_op;
318 else if (insn.mm_fp1_format.op == mm_ffloorw_op)
319 func = ffloor_op;
320 else if (insn.mm_fp1_format.op == mm_fceill_op)
321 func = fceill_op;
322 else if (insn.mm_fp1_format.op == mm_fceilw_op)
323 func = fceil_op;
324 else if (insn.mm_fp1_format.op == mm_ftruncl_op)
325 func = ftruncl_op;
326 else if (insn.mm_fp1_format.op == mm_ftruncw_op)
327 func = ftrunc_op;
328 else if (insn.mm_fp1_format.op == mm_froundl_op)
329 func = froundl_op;
330 else if (insn.mm_fp1_format.op == mm_froundw_op)
331 func = fround_op;
332 else if (insn.mm_fp1_format.op == mm_fcvtl_op)
333 func = fcvtl_op;
334 else
335 func = fcvtw_op;
336 mips32_insn.fp0_format.opcode = cop1_op;
337 mips32_insn.fp0_format.fmt =
338 sd_format[insn.mm_fp1_format.fmt];
339 mips32_insn.fp0_format.ft = 0;
340 mips32_insn.fp0_format.fs =
341 insn.mm_fp1_format.fs;
342 mips32_insn.fp0_format.fd =
343 insn.mm_fp1_format.rt;
344 mips32_insn.fp0_format.func = func;
345 break;
346 case mm_frsqrt_op:
347 case mm_fsqrt_op:
348 case mm_frecip_op:
349 if (insn.mm_fp1_format.op == mm_frsqrt_op)
350 func = frsqrt_op;
351 else if (insn.mm_fp1_format.op == mm_fsqrt_op)
352 func = fsqrt_op;
353 else
354 func = frecip_op;
355 mips32_insn.fp0_format.opcode = cop1_op;
356 mips32_insn.fp0_format.fmt =
357 sdps_format[insn.mm_fp1_format.fmt];
358 mips32_insn.fp0_format.ft = 0;
359 mips32_insn.fp0_format.fs =
360 insn.mm_fp1_format.fs;
361 mips32_insn.fp0_format.fd =
362 insn.mm_fp1_format.rt;
363 mips32_insn.fp0_format.func = func;
364 break;
365 case mm_mfc1_op:
366 case mm_mtc1_op:
367 case mm_cfc1_op:
368 case mm_ctc1_op:
369 case mm_mfhc1_op:
370 case mm_mthc1_op:
371 if (insn.mm_fp1_format.op == mm_mfc1_op)
372 op = mfc_op;
373 else if (insn.mm_fp1_format.op == mm_mtc1_op)
374 op = mtc_op;
375 else if (insn.mm_fp1_format.op == mm_cfc1_op)
376 op = cfc_op;
377 else if (insn.mm_fp1_format.op == mm_ctc1_op)
378 op = ctc_op;
379 else if (insn.mm_fp1_format.op == mm_mfhc1_op)
380 op = mfhc_op;
381 else
382 op = mthc_op;
383 mips32_insn.fp1_format.opcode = cop1_op;
384 mips32_insn.fp1_format.op = op;
385 mips32_insn.fp1_format.rt =
386 insn.mm_fp1_format.rt;
387 mips32_insn.fp1_format.fs =
388 insn.mm_fp1_format.fs;
389 mips32_insn.fp1_format.fd = 0;
390 mips32_insn.fp1_format.func = 0;
391 break;
392 default:
393 return SIGILL;
394 }
395 break;
396 case mm_32f_74_op: /* c.cond.fmt */
397 mips32_insn.fp0_format.opcode = cop1_op;
398 mips32_insn.fp0_format.fmt =
399 sdps_format[insn.mm_fp4_format.fmt];
400 mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
401 mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
402 mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
403 mips32_insn.fp0_format.func =
404 insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
405 break;
406 default:
407 return SIGILL;
408 }
409 break;
410 default:
411 return SIGILL;
412 }
413
414 *insn_ptr = mips32_insn;
415 return 0;
416}
417
418/*
419 * Redundant with logic already in kernel/branch.c,
420 * embedded in compute_return_epc. At some point,
421 * a single subroutine should be used across both
422 * modules.
423 */
424int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
425 unsigned long *contpc)
426{
427 union mips_instruction insn = (union mips_instruction)dec_insn.insn;
428 unsigned int fcr31;
429 unsigned int bit = 0;
430 unsigned int bit0;
431 union fpureg *fpr;
432
433 switch (insn.i_format.opcode) {
434 case spec_op:
435 switch (insn.r_format.func) {
436 case jalr_op:
437 if (insn.r_format.rd != 0) {
438 regs->regs[insn.r_format.rd] =
439 regs->cp0_epc + dec_insn.pc_inc +
440 dec_insn.next_pc_inc;
441 }
442 fallthrough;
443 case jr_op:
444 /* For R6, JR already emulated in jalr_op */
445 if (NO_R6EMU && insn.r_format.func == jr_op)
446 break;
447 *contpc = regs->regs[insn.r_format.rs];
448 return 1;
449 }
450 break;
451 case bcond_op:
452 switch (insn.i_format.rt) {
453 case bltzal_op:
454 case bltzall_op:
455 if (NO_R6EMU && (insn.i_format.rs ||
456 insn.i_format.rt == bltzall_op))
457 break;
458
459 regs->regs[31] = regs->cp0_epc +
460 dec_insn.pc_inc +
461 dec_insn.next_pc_inc;
462 fallthrough;
463 case bltzl_op:
464 if (NO_R6EMU)
465 break;
466 fallthrough;
467 case bltz_op:
468 if ((long)regs->regs[insn.i_format.rs] < 0)
469 *contpc = regs->cp0_epc +
470 dec_insn.pc_inc +
471 (insn.i_format.simmediate << 2);
472 else
473 *contpc = regs->cp0_epc +
474 dec_insn.pc_inc +
475 dec_insn.next_pc_inc;
476 return 1;
477 case bgezal_op:
478 case bgezall_op:
479 if (NO_R6EMU && (insn.i_format.rs ||
480 insn.i_format.rt == bgezall_op))
481 break;
482
483 regs->regs[31] = regs->cp0_epc +
484 dec_insn.pc_inc +
485 dec_insn.next_pc_inc;
486 fallthrough;
487 case bgezl_op:
488 if (NO_R6EMU)
489 break;
490 fallthrough;
491 case bgez_op:
492 if ((long)regs->regs[insn.i_format.rs] >= 0)
493 *contpc = regs->cp0_epc +
494 dec_insn.pc_inc +
495 (insn.i_format.simmediate << 2);
496 else
497 *contpc = regs->cp0_epc +
498 dec_insn.pc_inc +
499 dec_insn.next_pc_inc;
500 return 1;
501 }
502 break;
503 case jalx_op:
504 set_isa16_mode(bit);
505 fallthrough;
506 case jal_op:
507 regs->regs[31] = regs->cp0_epc +
508 dec_insn.pc_inc +
509 dec_insn.next_pc_inc;
510 fallthrough;
511 case j_op:
512 *contpc = regs->cp0_epc + dec_insn.pc_inc;
513 *contpc >>= 28;
514 *contpc <<= 28;
515 *contpc |= (insn.j_format.target << 2);
516 /* Set microMIPS mode bit: XOR for jalx. */
517 *contpc ^= bit;
518 return 1;
519 case beql_op:
520 if (NO_R6EMU)
521 break;
522 fallthrough;
523 case beq_op:
524 if (regs->regs[insn.i_format.rs] ==
525 regs->regs[insn.i_format.rt])
526 *contpc = regs->cp0_epc +
527 dec_insn.pc_inc +
528 (insn.i_format.simmediate << 2);
529 else
530 *contpc = regs->cp0_epc +
531 dec_insn.pc_inc +
532 dec_insn.next_pc_inc;
533 return 1;
534 case bnel_op:
535 if (NO_R6EMU)
536 break;
537 fallthrough;
538 case bne_op:
539 if (regs->regs[insn.i_format.rs] !=
540 regs->regs[insn.i_format.rt])
541 *contpc = regs->cp0_epc +
542 dec_insn.pc_inc +
543 (insn.i_format.simmediate << 2);
544 else
545 *contpc = regs->cp0_epc +
546 dec_insn.pc_inc +
547 dec_insn.next_pc_inc;
548 return 1;
549 case blezl_op:
550 if (!insn.i_format.rt && NO_R6EMU)
551 break;
552 fallthrough;
553 case blez_op:
554
555 /*
556 * Compact branches for R6 for the
557 * blez and blezl opcodes.
558 * BLEZ | rs = 0 | rt != 0 == BLEZALC
559 * BLEZ | rs = rt != 0 == BGEZALC
560 * BLEZ | rs != 0 | rt != 0 == BGEUC
561 * BLEZL | rs = 0 | rt != 0 == BLEZC
562 * BLEZL | rs = rt != 0 == BGEZC
563 * BLEZL | rs != 0 | rt != 0 == BGEC
564 *
565 * For real BLEZ{,L}, rt is always 0.
566 */
567 if (cpu_has_mips_r6 && insn.i_format.rt) {
568 if ((insn.i_format.opcode == blez_op) &&
569 ((!insn.i_format.rs && insn.i_format.rt) ||
570 (insn.i_format.rs == insn.i_format.rt)))
571 regs->regs[31] = regs->cp0_epc +
572 dec_insn.pc_inc;
573 *contpc = regs->cp0_epc + dec_insn.pc_inc +
574 dec_insn.next_pc_inc;
575
576 return 1;
577 }
578 if ((long)regs->regs[insn.i_format.rs] <= 0)
579 *contpc = regs->cp0_epc +
580 dec_insn.pc_inc +
581 (insn.i_format.simmediate << 2);
582 else
583 *contpc = regs->cp0_epc +
584 dec_insn.pc_inc +
585 dec_insn.next_pc_inc;
586 return 1;
587 case bgtzl_op:
588 if (!insn.i_format.rt && NO_R6EMU)
589 break;
590 fallthrough;
591 case bgtz_op:
592 /*
593 * Compact branches for R6 for the
594 * bgtz and bgtzl opcodes.
595 * BGTZ | rs = 0 | rt != 0 == BGTZALC
596 * BGTZ | rs = rt != 0 == BLTZALC
597 * BGTZ | rs != 0 | rt != 0 == BLTUC
598 * BGTZL | rs = 0 | rt != 0 == BGTZC
599 * BGTZL | rs = rt != 0 == BLTZC
600 * BGTZL | rs != 0 | rt != 0 == BLTC
601 *
602 * *ZALC varint for BGTZ &&& rt != 0
603 * For real GTZ{,L}, rt is always 0.
604 */
605 if (cpu_has_mips_r6 && insn.i_format.rt) {
606 if ((insn.i_format.opcode == blez_op) &&
607 ((!insn.i_format.rs && insn.i_format.rt) ||
608 (insn.i_format.rs == insn.i_format.rt)))
609 regs->regs[31] = regs->cp0_epc +
610 dec_insn.pc_inc;
611 *contpc = regs->cp0_epc + dec_insn.pc_inc +
612 dec_insn.next_pc_inc;
613
614 return 1;
615 }
616
617 if ((long)regs->regs[insn.i_format.rs] > 0)
618 *contpc = regs->cp0_epc +
619 dec_insn.pc_inc +
620 (insn.i_format.simmediate << 2);
621 else
622 *contpc = regs->cp0_epc +
623 dec_insn.pc_inc +
624 dec_insn.next_pc_inc;
625 return 1;
626 case pop10_op:
627 case pop30_op:
628 if (!cpu_has_mips_r6)
629 break;
630 if (insn.i_format.rt && !insn.i_format.rs)
631 regs->regs[31] = regs->cp0_epc + 4;
632 *contpc = regs->cp0_epc + dec_insn.pc_inc +
633 dec_insn.next_pc_inc;
634
635 return 1;
636#ifdef CONFIG_CPU_CAVIUM_OCTEON
637 case lwc2_op: /* This is bbit0 on Octeon */
638 if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
639 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
640 else
641 *contpc = regs->cp0_epc + 8;
642 return 1;
643 case ldc2_op: /* This is bbit032 on Octeon */
644 if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
645 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
646 else
647 *contpc = regs->cp0_epc + 8;
648 return 1;
649 case swc2_op: /* This is bbit1 on Octeon */
650 if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
651 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
652 else
653 *contpc = regs->cp0_epc + 8;
654 return 1;
655 case sdc2_op: /* This is bbit132 on Octeon */
656 if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
657 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
658 else
659 *contpc = regs->cp0_epc + 8;
660 return 1;
661#else
662 case bc6_op:
663 /*
664 * Only valid for MIPS R6 but we can still end up
665 * here from a broken userland so just tell emulator
666 * this is not a branch and let it break later on.
667 */
668 if (!cpu_has_mips_r6)
669 break;
670 *contpc = regs->cp0_epc + dec_insn.pc_inc +
671 dec_insn.next_pc_inc;
672
673 return 1;
674 case balc6_op:
675 if (!cpu_has_mips_r6)
676 break;
677 regs->regs[31] = regs->cp0_epc + 4;
678 *contpc = regs->cp0_epc + dec_insn.pc_inc +
679 dec_insn.next_pc_inc;
680
681 return 1;
682 case pop66_op:
683 if (!cpu_has_mips_r6)
684 break;
685 *contpc = regs->cp0_epc + dec_insn.pc_inc +
686 dec_insn.next_pc_inc;
687
688 return 1;
689 case pop76_op:
690 if (!cpu_has_mips_r6)
691 break;
692 if (!insn.i_format.rs)
693 regs->regs[31] = regs->cp0_epc + 4;
694 *contpc = regs->cp0_epc + dec_insn.pc_inc +
695 dec_insn.next_pc_inc;
696
697 return 1;
698#endif
699 case cop0_op:
700 case cop1_op:
701 /* Need to check for R6 bc1nez and bc1eqz branches */
702 if (cpu_has_mips_r6 &&
703 ((insn.i_format.rs == bc1eqz_op) ||
704 (insn.i_format.rs == bc1nez_op))) {
705 bit = 0;
706 fpr = ¤t->thread.fpu.fpr[insn.i_format.rt];
707 bit0 = get_fpr32(fpr, 0) & 0x1;
708 switch (insn.i_format.rs) {
709 case bc1eqz_op:
710 bit = bit0 == 0;
711 break;
712 case bc1nez_op:
713 bit = bit0 != 0;
714 break;
715 }
716 if (bit)
717 *contpc = regs->cp0_epc +
718 dec_insn.pc_inc +
719 (insn.i_format.simmediate << 2);
720 else
721 *contpc = regs->cp0_epc +
722 dec_insn.pc_inc +
723 dec_insn.next_pc_inc;
724
725 return 1;
726 }
727 /* R2/R6 compatible cop1 instruction */
728 fallthrough;
729 case cop2_op:
730 case cop1x_op:
731 if (insn.i_format.rs == bc_op) {
732 preempt_disable();
733 if (is_fpu_owner())
734 fcr31 = read_32bit_cp1_register(CP1_STATUS);
735 else
736 fcr31 = current->thread.fpu.fcr31;
737 preempt_enable();
738
739 bit = (insn.i_format.rt >> 2);
740 bit += (bit != 0);
741 bit += 23;
742 switch (insn.i_format.rt & 3) {
743 case 0: /* bc1f */
744 case 2: /* bc1fl */
745 if (~fcr31 & (1 << bit))
746 *contpc = regs->cp0_epc +
747 dec_insn.pc_inc +
748 (insn.i_format.simmediate << 2);
749 else
750 *contpc = regs->cp0_epc +
751 dec_insn.pc_inc +
752 dec_insn.next_pc_inc;
753 return 1;
754 case 1: /* bc1t */
755 case 3: /* bc1tl */
756 if (fcr31 & (1 << bit))
757 *contpc = regs->cp0_epc +
758 dec_insn.pc_inc +
759 (insn.i_format.simmediate << 2);
760 else
761 *contpc = regs->cp0_epc +
762 dec_insn.pc_inc +
763 dec_insn.next_pc_inc;
764 return 1;
765 }
766 }
767 break;
768 }
769 return 0;
770}
771
772/*
773 * In the Linux kernel, we support selection of FPR format on the
774 * basis of the Status.FR bit. If an FPU is not present, the FR bit
775 * is hardwired to zero, which would imply a 32-bit FPU even for
776 * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
777 * FPU emu is slow and bulky and optimizing this function offers fairly
778 * sizeable benefits so we try to be clever and make this function return
779 * a constant whenever possible, that is on 64-bit kernels without O32
780 * compatibility enabled and on 32-bit without 64-bit FPU support.
781 */
782static inline int cop1_64bit(struct pt_regs *xcp)
783{
784 if (IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_MIPS32_O32))
785 return 1;
786 else if (IS_ENABLED(CONFIG_32BIT) &&
787 !IS_ENABLED(CONFIG_MIPS_O32_FP64_SUPPORT))
788 return 0;
789
790 return !test_thread_flag(TIF_32BIT_FPREGS);
791}
792
793static inline bool hybrid_fprs(void)
794{
795 return test_thread_flag(TIF_HYBRID_FPREGS);
796}
797
798#define SIFROMREG(si, x) \
799do { \
800 if (cop1_64bit(xcp) && !hybrid_fprs()) \
801 (si) = (int)get_fpr32(&ctx->fpr[x], 0); \
802 else \
803 (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \
804} while (0)
805
806#define SITOREG(si, x) \
807do { \
808 if (cop1_64bit(xcp) && !hybrid_fprs()) { \
809 unsigned int i; \
810 set_fpr32(&ctx->fpr[x], 0, si); \
811 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
812 set_fpr32(&ctx->fpr[x], i, 0); \
813 } else { \
814 set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si); \
815 } \
816} while (0)
817
818#define SIFROMHREG(si, x) ((si) = (int)get_fpr32(&ctx->fpr[x], 1))
819
820#define SITOHREG(si, x) \
821do { \
822 unsigned int i; \
823 set_fpr32(&ctx->fpr[x], 1, si); \
824 for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
825 set_fpr32(&ctx->fpr[x], i, 0); \
826} while (0)
827
828#define DIFROMREG(di, x) \
829 ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) ^ 1)], 0))
830
831#define DITOREG(di, x) \
832do { \
833 unsigned int fpr, i; \
834 fpr = (x) & ~(cop1_64bit(xcp) ^ 1); \
835 set_fpr64(&ctx->fpr[fpr], 0, di); \
836 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++) \
837 set_fpr64(&ctx->fpr[fpr], i, 0); \
838} while (0)
839
840#define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
841#define SPTOREG(sp, x) SITOREG((sp).bits, x)
842#define DPFROMREG(dp, x) DIFROMREG((dp).bits, x)
843#define DPTOREG(dp, x) DITOREG((dp).bits, x)
844
845/*
846 * Emulate a CFC1 instruction.
847 */
848static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
849 mips_instruction ir)
850{
851 u32 fcr31 = ctx->fcr31;
852 u32 value = 0;
853
854 switch (MIPSInst_RD(ir)) {
855 case FPCREG_CSR:
856 value = fcr31;
857 pr_debug("%p gpr[%d]<-csr=%08x\n",
858 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
859 break;
860
861 case FPCREG_FENR:
862 if (!cpu_has_mips_r)
863 break;
864 value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
865 MIPS_FENR_FS;
866 value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM);
867 pr_debug("%p gpr[%d]<-enr=%08x\n",
868 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
869 break;
870
871 case FPCREG_FEXR:
872 if (!cpu_has_mips_r)
873 break;
874 value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
875 pr_debug("%p gpr[%d]<-exr=%08x\n",
876 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
877 break;
878
879 case FPCREG_FCCR:
880 if (!cpu_has_mips_r)
881 break;
882 value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
883 MIPS_FCCR_COND0;
884 value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
885 (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0);
886 pr_debug("%p gpr[%d]<-ccr=%08x\n",
887 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
888 break;
889
890 case FPCREG_RID:
891 value = boot_cpu_data.fpu_id;
892 break;
893
894 default:
895 break;
896 }
897
898 if (MIPSInst_RT(ir))
899 xcp->regs[MIPSInst_RT(ir)] = value;
900}
901
902/*
903 * Emulate a CTC1 instruction.
904 */
905static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
906 mips_instruction ir)
907{
908 u32 fcr31 = ctx->fcr31;
909 u32 value;
910 u32 mask;
911
912 if (MIPSInst_RT(ir) == 0)
913 value = 0;
914 else
915 value = xcp->regs[MIPSInst_RT(ir)];
916
917 switch (MIPSInst_RD(ir)) {
918 case FPCREG_CSR:
919 pr_debug("%p gpr[%d]->csr=%08x\n",
920 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
921
922 /* Preserve read-only bits. */
923 mask = boot_cpu_data.fpu_msk31;
924 fcr31 = (value & ~mask) | (fcr31 & mask);
925 break;
926
927 case FPCREG_FENR:
928 if (!cpu_has_mips_r)
929 break;
930 pr_debug("%p gpr[%d]->enr=%08x\n",
931 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
932 fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM);
933 fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
934 FPU_CSR_FS;
935 fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM);
936 break;
937
938 case FPCREG_FEXR:
939 if (!cpu_has_mips_r)
940 break;
941 pr_debug("%p gpr[%d]->exr=%08x\n",
942 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
943 fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S);
944 fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
945 break;
946
947 case FPCREG_FCCR:
948 if (!cpu_has_mips_r)
949 break;
950 pr_debug("%p gpr[%d]->ccr=%08x\n",
951 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
952 fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND);
953 fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
954 FPU_CSR_COND;
955 fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
956 FPU_CSR_CONDX;
957 break;
958
959 default:
960 break;
961 }
962
963 ctx->fcr31 = fcr31;
964}
965
966/*
967 * Emulate the single floating point instruction pointed at by EPC.
968 * Two instructions if the instruction is in a branch delay slot.
969 */
970
971static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
972 struct mm_decoded_insn dec_insn, void __user **fault_addr)
973{
974 unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
975 unsigned int cond, cbit, bit0;
976 mips_instruction ir;
977 int likely, pc_inc;
978 union fpureg *fpr;
979 u32 __user *wva;
980 u64 __user *dva;
981 u32 wval;
982 u64 dval;
983 int sig;
984
985 /*
986 * These are giving gcc a gentle hint about what to expect in
987 * dec_inst in order to do better optimization.
988 */
989 if (!cpu_has_mmips && dec_insn.micro_mips_mode)
990 unreachable();
991
992 /* XXX NEC Vr54xx bug workaround */
993 if (delay_slot(xcp)) {
994 if (dec_insn.micro_mips_mode) {
995 if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
996 clear_delay_slot(xcp);
997 } else {
998 if (!isBranchInstr(xcp, dec_insn, &contpc))
999 clear_delay_slot(xcp);
1000 }
1001 }
1002
1003 if (delay_slot(xcp)) {
1004 /*
1005 * The instruction to be emulated is in a branch delay slot
1006 * which means that we have to emulate the branch instruction
1007 * BEFORE we do the cop1 instruction.
1008 *
1009 * This branch could be a COP1 branch, but in that case we
1010 * would have had a trap for that instruction, and would not
1011 * come through this route.
1012 *
1013 * Linux MIPS branch emulator operates on context, updating the
1014 * cp0_epc.
1015 */
1016 ir = dec_insn.next_insn; /* process delay slot instr */
1017 pc_inc = dec_insn.next_pc_inc;
1018 } else {
1019 ir = dec_insn.insn; /* process current instr */
1020 pc_inc = dec_insn.pc_inc;
1021 }
1022
1023 /*
1024 * Since microMIPS FPU instructios are a subset of MIPS32 FPU
1025 * instructions, we want to convert microMIPS FPU instructions
1026 * into MIPS32 instructions so that we could reuse all of the
1027 * FPU emulation code.
1028 *
1029 * NOTE: We cannot do this for branch instructions since they
1030 * are not a subset. Example: Cannot emulate a 16-bit
1031 * aligned target address with a MIPS32 instruction.
1032 */
1033 if (dec_insn.micro_mips_mode) {
1034 /*
1035 * If next instruction is a 16-bit instruction, then
1036 * it cannot be a FPU instruction. This could happen
1037 * since we can be called for non-FPU instructions.
1038 */
1039 if ((pc_inc == 2) ||
1040 (microMIPS32_to_MIPS32((union mips_instruction *)&ir)
1041 == SIGILL))
1042 return SIGILL;
1043 }
1044
1045emul:
1046 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
1047 MIPS_FPU_EMU_INC_STATS(emulated);
1048 switch (MIPSInst_OPCODE(ir)) {
1049 case ldc1_op:
1050 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1051 MIPSInst_SIMM(ir));
1052 MIPS_FPU_EMU_INC_STATS(loads);
1053
1054 if (!access_ok(dva, sizeof(u64))) {
1055 MIPS_FPU_EMU_INC_STATS(errors);
1056 *fault_addr = dva;
1057 return SIGBUS;
1058 }
1059 if (__get_user(dval, dva)) {
1060 MIPS_FPU_EMU_INC_STATS(errors);
1061 *fault_addr = dva;
1062 return SIGSEGV;
1063 }
1064 DITOREG(dval, MIPSInst_RT(ir));
1065 break;
1066
1067 case sdc1_op:
1068 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1069 MIPSInst_SIMM(ir));
1070 MIPS_FPU_EMU_INC_STATS(stores);
1071 DIFROMREG(dval, MIPSInst_RT(ir));
1072 if (!access_ok(dva, sizeof(u64))) {
1073 MIPS_FPU_EMU_INC_STATS(errors);
1074 *fault_addr = dva;
1075 return SIGBUS;
1076 }
1077 if (__put_user(dval, dva)) {
1078 MIPS_FPU_EMU_INC_STATS(errors);
1079 *fault_addr = dva;
1080 return SIGSEGV;
1081 }
1082 break;
1083
1084 case lwc1_op:
1085 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1086 MIPSInst_SIMM(ir));
1087 MIPS_FPU_EMU_INC_STATS(loads);
1088 if (!access_ok(wva, sizeof(u32))) {
1089 MIPS_FPU_EMU_INC_STATS(errors);
1090 *fault_addr = wva;
1091 return SIGBUS;
1092 }
1093 if (__get_user(wval, wva)) {
1094 MIPS_FPU_EMU_INC_STATS(errors);
1095 *fault_addr = wva;
1096 return SIGSEGV;
1097 }
1098 SITOREG(wval, MIPSInst_RT(ir));
1099 break;
1100
1101 case swc1_op:
1102 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1103 MIPSInst_SIMM(ir));
1104 MIPS_FPU_EMU_INC_STATS(stores);
1105 SIFROMREG(wval, MIPSInst_RT(ir));
1106 if (!access_ok(wva, sizeof(u32))) {
1107 MIPS_FPU_EMU_INC_STATS(errors);
1108 *fault_addr = wva;
1109 return SIGBUS;
1110 }
1111 if (__put_user(wval, wva)) {
1112 MIPS_FPU_EMU_INC_STATS(errors);
1113 *fault_addr = wva;
1114 return SIGSEGV;
1115 }
1116 break;
1117
1118 case cop1_op:
1119 switch (MIPSInst_RS(ir)) {
1120 case dmfc_op:
1121 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1122 return SIGILL;
1123
1124 /* copregister fs -> gpr[rt] */
1125 if (MIPSInst_RT(ir) != 0) {
1126 DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1127 MIPSInst_RD(ir));
1128 }
1129 break;
1130
1131 case dmtc_op:
1132 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1133 return SIGILL;
1134
1135 /* copregister fs <- rt */
1136 DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1137 break;
1138
1139 case mfhc_op:
1140 if (!cpu_has_mips_r2_r6)
1141 return SIGILL;
1142
1143 /* copregister rd -> gpr[rt] */
1144 if (MIPSInst_RT(ir) != 0) {
1145 SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
1146 MIPSInst_RD(ir));
1147 }
1148 break;
1149
1150 case mthc_op:
1151 if (!cpu_has_mips_r2_r6)
1152 return SIGILL;
1153
1154 /* copregister rd <- gpr[rt] */
1155 SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1156 break;
1157
1158 case mfc_op:
1159 /* copregister rd -> gpr[rt] */
1160 if (MIPSInst_RT(ir) != 0) {
1161 SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1162 MIPSInst_RD(ir));
1163 }
1164 break;
1165
1166 case mtc_op:
1167 /* copregister rd <- rt */
1168 SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1169 break;
1170
1171 case cfc_op:
1172 /* cop control register rd -> gpr[rt] */
1173 cop1_cfc(xcp, ctx, ir);
1174 break;
1175
1176 case ctc_op:
1177 /* copregister rd <- rt */
1178 cop1_ctc(xcp, ctx, ir);
1179 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1180 return SIGFPE;
1181 }
1182 break;
1183
1184 case bc1eqz_op:
1185 case bc1nez_op:
1186 if (!cpu_has_mips_r6 || delay_slot(xcp))
1187 return SIGILL;
1188
1189 likely = 0;
1190 cond = 0;
1191 fpr = ¤t->thread.fpu.fpr[MIPSInst_RT(ir)];
1192 bit0 = get_fpr32(fpr, 0) & 0x1;
1193 switch (MIPSInst_RS(ir)) {
1194 case bc1eqz_op:
1195 MIPS_FPU_EMU_INC_STATS(bc1eqz);
1196 cond = bit0 == 0;
1197 break;
1198 case bc1nez_op:
1199 MIPS_FPU_EMU_INC_STATS(bc1nez);
1200 cond = bit0 != 0;
1201 break;
1202 }
1203 goto branch_common;
1204
1205 case bc_op:
1206 if (delay_slot(xcp))
1207 return SIGILL;
1208
1209 if (cpu_has_mips_4_5_r)
1210 cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
1211 else
1212 cbit = FPU_CSR_COND;
1213 cond = ctx->fcr31 & cbit;
1214
1215 likely = 0;
1216 switch (MIPSInst_RT(ir) & 3) {
1217 case bcfl_op:
1218 if (cpu_has_mips_2_3_4_5_r)
1219 likely = 1;
1220 fallthrough;
1221 case bcf_op:
1222 cond = !cond;
1223 break;
1224 case bctl_op:
1225 if (cpu_has_mips_2_3_4_5_r)
1226 likely = 1;
1227 fallthrough;
1228 case bct_op:
1229 break;
1230 }
1231branch_common:
1232 MIPS_FPU_EMU_INC_STATS(branches);
1233 set_delay_slot(xcp);
1234 if (cond) {
1235 /*
1236 * Branch taken: emulate dslot instruction
1237 */
1238 unsigned long bcpc;
1239
1240 /*
1241 * Remember EPC at the branch to point back
1242 * at so that any delay-slot instruction
1243 * signal is not silently ignored.
1244 */
1245 bcpc = xcp->cp0_epc;
1246 xcp->cp0_epc += dec_insn.pc_inc;
1247
1248 contpc = MIPSInst_SIMM(ir);
1249 ir = dec_insn.next_insn;
1250 if (dec_insn.micro_mips_mode) {
1251 contpc = (xcp->cp0_epc + (contpc << 1));
1252
1253 /* If 16-bit instruction, not FPU. */
1254 if ((dec_insn.next_pc_inc == 2) ||
1255 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
1256
1257 /*
1258 * Since this instruction will
1259 * be put on the stack with
1260 * 32-bit words, get around
1261 * this problem by putting a
1262 * NOP16 as the second one.
1263 */
1264 if (dec_insn.next_pc_inc == 2)
1265 ir = (ir & (~0xffff)) | MM_NOP16;
1266
1267 /*
1268 * Single step the non-CP1
1269 * instruction in the dslot.
1270 */
1271 sig = mips_dsemul(xcp, ir,
1272 bcpc, contpc);
1273 if (sig < 0)
1274 break;
1275 if (sig)
1276 xcp->cp0_epc = bcpc;
1277 /*
1278 * SIGILL forces out of
1279 * the emulation loop.
1280 */
1281 return sig ? sig : SIGILL;
1282 }
1283 } else
1284 contpc = (xcp->cp0_epc + (contpc << 2));
1285
1286 switch (MIPSInst_OPCODE(ir)) {
1287 case lwc1_op:
1288 case swc1_op:
1289 goto emul;
1290
1291 case ldc1_op:
1292 case sdc1_op:
1293 if (cpu_has_mips_2_3_4_5_r)
1294 goto emul;
1295
1296 goto bc_sigill;
1297
1298 case cop1_op:
1299 goto emul;
1300
1301 case cop1x_op:
1302 if (cpu_has_mips_4_5_64_r2_r6)
1303 /* its one of ours */
1304 goto emul;
1305
1306 goto bc_sigill;
1307
1308 case spec_op:
1309 switch (MIPSInst_FUNC(ir)) {
1310 case movc_op:
1311 if (cpu_has_mips_4_5_r)
1312 goto emul;
1313
1314 goto bc_sigill;
1315 }
1316 break;
1317
1318 bc_sigill:
1319 xcp->cp0_epc = bcpc;
1320 return SIGILL;
1321 }
1322
1323 /*
1324 * Single step the non-cp1
1325 * instruction in the dslot
1326 */
1327 sig = mips_dsemul(xcp, ir, bcpc, contpc);
1328 if (sig < 0)
1329 break;
1330 if (sig)
1331 xcp->cp0_epc = bcpc;
1332 /* SIGILL forces out of the emulation loop. */
1333 return sig ? sig : SIGILL;
1334 } else if (likely) { /* branch not taken */
1335 /*
1336 * branch likely nullifies
1337 * dslot if not taken
1338 */
1339 xcp->cp0_epc += dec_insn.pc_inc;
1340 contpc += dec_insn.pc_inc;
1341 /*
1342 * else continue & execute
1343 * dslot as normal insn
1344 */
1345 }
1346 break;
1347
1348 default:
1349 if (!(MIPSInst_RS(ir) & 0x10))
1350 return SIGILL;
1351
1352 /* a real fpu computation instruction */
1353 sig = fpu_emu(xcp, ctx, ir);
1354 if (sig)
1355 return sig;
1356 }
1357 break;
1358
1359 case cop1x_op:
1360 if (!cpu_has_mips_4_5_64_r2_r6)
1361 return SIGILL;
1362
1363 sig = fpux_emu(xcp, ctx, ir, fault_addr);
1364 if (sig)
1365 return sig;
1366 break;
1367
1368 case spec_op:
1369 if (!cpu_has_mips_4_5_r)
1370 return SIGILL;
1371
1372 if (MIPSInst_FUNC(ir) != movc_op)
1373 return SIGILL;
1374 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
1375 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
1376 xcp->regs[MIPSInst_RD(ir)] =
1377 xcp->regs[MIPSInst_RS(ir)];
1378 break;
1379 default:
1380 return SIGILL;
1381 }
1382
1383 /* we did it !! */
1384 xcp->cp0_epc = contpc;
1385 clear_delay_slot(xcp);
1386
1387 return 0;
1388}
1389
1390/*
1391 * Conversion table from MIPS compare ops 48-63
1392 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
1393 */
1394static const unsigned char cmptab[8] = {
1395 0, /* cmp_0 (sig) cmp_sf */
1396 IEEE754_CUN, /* cmp_un (sig) cmp_ngle */
1397 IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */
1398 IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */
1399 IEEE754_CLT, /* cmp_olt (sig) cmp_lt */
1400 IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */
1401 IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */
1402 IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */
1403};
1404
1405static const unsigned char negative_cmptab[8] = {
1406 0, /* Reserved */
1407 IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ,
1408 IEEE754_CLT | IEEE754_CGT | IEEE754_CUN,
1409 IEEE754_CLT | IEEE754_CGT,
1410 /* Reserved */
1411};
1412
1413
1414/*
1415 * Additional MIPS4 instructions
1416 */
1417
1418#define DEF3OP(name, p, f1, f2, f3) \
1419static union ieee754##p fpemu_##p##_##name(union ieee754##p r, \
1420 union ieee754##p s, union ieee754##p t) \
1421{ \
1422 struct _ieee754_csr ieee754_csr_save; \
1423 s = f1(s, t); \
1424 ieee754_csr_save = ieee754_csr; \
1425 s = f2(s, r); \
1426 ieee754_csr_save.cx |= ieee754_csr.cx; \
1427 ieee754_csr_save.sx |= ieee754_csr.sx; \
1428 s = f3(s); \
1429 ieee754_csr.cx |= ieee754_csr_save.cx; \
1430 ieee754_csr.sx |= ieee754_csr_save.sx; \
1431 return s; \
1432}
1433
1434static union ieee754dp fpemu_dp_recip(union ieee754dp d)
1435{
1436 return ieee754dp_div(ieee754dp_one(0), d);
1437}
1438
1439static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
1440{
1441 return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
1442}
1443
1444static union ieee754sp fpemu_sp_recip(union ieee754sp s)
1445{
1446 return ieee754sp_div(ieee754sp_one(0), s);
1447}
1448
1449static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s)
1450{
1451 return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
1452}
1453
1454DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
1455DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
1456DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
1457DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
1458DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
1459DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
1460DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
1461DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
1462
1463static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1464 mips_instruction ir, void __user **fault_addr)
1465{
1466 unsigned int rcsr = 0; /* resulting csr */
1467
1468 MIPS_FPU_EMU_INC_STATS(cp1xops);
1469
1470 switch (MIPSInst_FMA_FFMT(ir)) {
1471 case s_fmt:{ /* 0 */
1472
1473 union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
1474 union ieee754sp fd, fr, fs, ft;
1475 u32 __user *va;
1476 u32 val;
1477
1478 switch (MIPSInst_FUNC(ir)) {
1479 case lwxc1_op:
1480 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1481 xcp->regs[MIPSInst_FT(ir)]);
1482
1483 MIPS_FPU_EMU_INC_STATS(loads);
1484 if (!access_ok(va, sizeof(u32))) {
1485 MIPS_FPU_EMU_INC_STATS(errors);
1486 *fault_addr = va;
1487 return SIGBUS;
1488 }
1489 if (__get_user(val, va)) {
1490 MIPS_FPU_EMU_INC_STATS(errors);
1491 *fault_addr = va;
1492 return SIGSEGV;
1493 }
1494 SITOREG(val, MIPSInst_FD(ir));
1495 break;
1496
1497 case swxc1_op:
1498 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1499 xcp->regs[MIPSInst_FT(ir)]);
1500
1501 MIPS_FPU_EMU_INC_STATS(stores);
1502
1503 SIFROMREG(val, MIPSInst_FS(ir));
1504 if (!access_ok(va, sizeof(u32))) {
1505 MIPS_FPU_EMU_INC_STATS(errors);
1506 *fault_addr = va;
1507 return SIGBUS;
1508 }
1509 if (put_user(val, va)) {
1510 MIPS_FPU_EMU_INC_STATS(errors);
1511 *fault_addr = va;
1512 return SIGSEGV;
1513 }
1514 break;
1515
1516 case madd_s_op:
1517 if (cpu_has_mac2008_only)
1518 handler = ieee754sp_madd;
1519 else
1520 handler = fpemu_sp_madd;
1521 goto scoptop;
1522 case msub_s_op:
1523 if (cpu_has_mac2008_only)
1524 handler = ieee754sp_msub;
1525 else
1526 handler = fpemu_sp_msub;
1527 goto scoptop;
1528 case nmadd_s_op:
1529 if (cpu_has_mac2008_only)
1530 handler = ieee754sp_nmadd;
1531 else
1532 handler = fpemu_sp_nmadd;
1533 goto scoptop;
1534 case nmsub_s_op:
1535 if (cpu_has_mac2008_only)
1536 handler = ieee754sp_nmsub;
1537 else
1538 handler = fpemu_sp_nmsub;
1539 goto scoptop;
1540
1541 scoptop:
1542 SPFROMREG(fr, MIPSInst_FR(ir));
1543 SPFROMREG(fs, MIPSInst_FS(ir));
1544 SPFROMREG(ft, MIPSInst_FT(ir));
1545 fd = (*handler) (fr, fs, ft);
1546 SPTOREG(fd, MIPSInst_FD(ir));
1547
1548 copcsr:
1549 if (ieee754_cxtest(IEEE754_INEXACT)) {
1550 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1551 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1552 }
1553 if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1554 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1555 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1556 }
1557 if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1558 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1559 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1560 }
1561 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1562 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1563 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1564 }
1565
1566 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1567 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1568 /*printk ("SIGFPE: FPU csr = %08x\n",
1569 ctx->fcr31); */
1570 return SIGFPE;
1571 }
1572
1573 break;
1574
1575 default:
1576 return SIGILL;
1577 }
1578 break;
1579 }
1580
1581 case d_fmt:{ /* 1 */
1582 union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
1583 union ieee754dp fd, fr, fs, ft;
1584 u64 __user *va;
1585 u64 val;
1586
1587 switch (MIPSInst_FUNC(ir)) {
1588 case ldxc1_op:
1589 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1590 xcp->regs[MIPSInst_FT(ir)]);
1591
1592 MIPS_FPU_EMU_INC_STATS(loads);
1593 if (!access_ok(va, sizeof(u64))) {
1594 MIPS_FPU_EMU_INC_STATS(errors);
1595 *fault_addr = va;
1596 return SIGBUS;
1597 }
1598 if (__get_user(val, va)) {
1599 MIPS_FPU_EMU_INC_STATS(errors);
1600 *fault_addr = va;
1601 return SIGSEGV;
1602 }
1603 DITOREG(val, MIPSInst_FD(ir));
1604 break;
1605
1606 case sdxc1_op:
1607 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1608 xcp->regs[MIPSInst_FT(ir)]);
1609
1610 MIPS_FPU_EMU_INC_STATS(stores);
1611 DIFROMREG(val, MIPSInst_FS(ir));
1612 if (!access_ok(va, sizeof(u64))) {
1613 MIPS_FPU_EMU_INC_STATS(errors);
1614 *fault_addr = va;
1615 return SIGBUS;
1616 }
1617 if (__put_user(val, va)) {
1618 MIPS_FPU_EMU_INC_STATS(errors);
1619 *fault_addr = va;
1620 return SIGSEGV;
1621 }
1622 break;
1623
1624 case madd_d_op:
1625 if (cpu_has_mac2008_only)
1626 handler = ieee754dp_madd;
1627 else
1628 handler = fpemu_dp_madd;
1629 goto dcoptop;
1630 case msub_d_op:
1631 if (cpu_has_mac2008_only)
1632 handler = ieee754dp_msub;
1633 else
1634 handler = fpemu_dp_msub;
1635 goto dcoptop;
1636 case nmadd_d_op:
1637 if (cpu_has_mac2008_only)
1638 handler = ieee754dp_nmadd;
1639 else
1640 handler = fpemu_dp_nmadd;
1641 goto dcoptop;
1642 case nmsub_d_op:
1643 if (cpu_has_mac2008_only)
1644 handler = ieee754dp_nmsub;
1645 else
1646 handler = fpemu_dp_nmsub;
1647 goto dcoptop;
1648
1649 dcoptop:
1650 DPFROMREG(fr, MIPSInst_FR(ir));
1651 DPFROMREG(fs, MIPSInst_FS(ir));
1652 DPFROMREG(ft, MIPSInst_FT(ir));
1653 fd = (*handler) (fr, fs, ft);
1654 DPTOREG(fd, MIPSInst_FD(ir));
1655 goto copcsr;
1656
1657 default:
1658 return SIGILL;
1659 }
1660 break;
1661 }
1662
1663 case 0x3:
1664 if (MIPSInst_FUNC(ir) != pfetch_op)
1665 return SIGILL;
1666
1667 /* ignore prefx operation */
1668 break;
1669
1670 default:
1671 return SIGILL;
1672 }
1673
1674 return 0;
1675}
1676
1677
1678
1679/*
1680 * Emulate a single COP1 arithmetic instruction.
1681 */
1682static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1683 mips_instruction ir)
1684{
1685 int rfmt; /* resulting format */
1686 unsigned int rcsr = 0; /* resulting csr */
1687 unsigned int oldrm;
1688 unsigned int cbit;
1689 unsigned int cond;
1690 union {
1691 union ieee754dp d;
1692 union ieee754sp s;
1693 int w;
1694 s64 l;
1695 } rv; /* resulting value */
1696 u64 bits;
1697
1698 MIPS_FPU_EMU_INC_STATS(cp1ops);
1699 switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
1700 case s_fmt: { /* 0 */
1701 union {
1702 union ieee754sp(*b) (union ieee754sp, union ieee754sp);
1703 union ieee754sp(*u) (union ieee754sp);
1704 } handler;
1705 union ieee754sp fd, fs, ft;
1706
1707 switch (MIPSInst_FUNC(ir)) {
1708 /* binary ops */
1709 case fadd_op:
1710 MIPS_FPU_EMU_INC_STATS(add_s);
1711 handler.b = ieee754sp_add;
1712 goto scopbop;
1713 case fsub_op:
1714 MIPS_FPU_EMU_INC_STATS(sub_s);
1715 handler.b = ieee754sp_sub;
1716 goto scopbop;
1717 case fmul_op:
1718 MIPS_FPU_EMU_INC_STATS(mul_s);
1719 handler.b = ieee754sp_mul;
1720 goto scopbop;
1721 case fdiv_op:
1722 MIPS_FPU_EMU_INC_STATS(div_s);
1723 handler.b = ieee754sp_div;
1724 goto scopbop;
1725
1726 /* unary ops */
1727 case fsqrt_op:
1728 if (!cpu_has_mips_2_3_4_5_r)
1729 return SIGILL;
1730
1731 MIPS_FPU_EMU_INC_STATS(sqrt_s);
1732 handler.u = ieee754sp_sqrt;
1733 goto scopuop;
1734
1735 /*
1736 * Note that on some MIPS IV implementations such as the
1737 * R5000 and R8000 the FSQRT and FRECIP instructions do not
1738 * achieve full IEEE-754 accuracy - however this emulator does.
1739 */
1740 case frsqrt_op:
1741 if (!cpu_has_mips_4_5_64_r2_r6)
1742 return SIGILL;
1743
1744 MIPS_FPU_EMU_INC_STATS(rsqrt_s);
1745 handler.u = fpemu_sp_rsqrt;
1746 goto scopuop;
1747
1748 case frecip_op:
1749 if (!cpu_has_mips_4_5_64_r2_r6)
1750 return SIGILL;
1751
1752 MIPS_FPU_EMU_INC_STATS(recip_s);
1753 handler.u = fpemu_sp_recip;
1754 goto scopuop;
1755
1756 case fmovc_op:
1757 if (!cpu_has_mips_4_5_r)
1758 return SIGILL;
1759
1760 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1761 if (((ctx->fcr31 & cond) != 0) !=
1762 ((MIPSInst_FT(ir) & 1) != 0))
1763 return 0;
1764 SPFROMREG(rv.s, MIPSInst_FS(ir));
1765 break;
1766
1767 case fmovz_op:
1768 if (!cpu_has_mips_4_5_r)
1769 return SIGILL;
1770
1771 if (xcp->regs[MIPSInst_FT(ir)] != 0)
1772 return 0;
1773 SPFROMREG(rv.s, MIPSInst_FS(ir));
1774 break;
1775
1776 case fmovn_op:
1777 if (!cpu_has_mips_4_5_r)
1778 return SIGILL;
1779
1780 if (xcp->regs[MIPSInst_FT(ir)] == 0)
1781 return 0;
1782 SPFROMREG(rv.s, MIPSInst_FS(ir));
1783 break;
1784
1785 case fseleqz_op:
1786 if (!cpu_has_mips_r6)
1787 return SIGILL;
1788
1789 MIPS_FPU_EMU_INC_STATS(seleqz_s);
1790 SPFROMREG(rv.s, MIPSInst_FT(ir));
1791 if (rv.w & 0x1)
1792 rv.w = 0;
1793 else
1794 SPFROMREG(rv.s, MIPSInst_FS(ir));
1795 break;
1796
1797 case fselnez_op:
1798 if (!cpu_has_mips_r6)
1799 return SIGILL;
1800
1801 MIPS_FPU_EMU_INC_STATS(selnez_s);
1802 SPFROMREG(rv.s, MIPSInst_FT(ir));
1803 if (rv.w & 0x1)
1804 SPFROMREG(rv.s, MIPSInst_FS(ir));
1805 else
1806 rv.w = 0;
1807 break;
1808
1809 case fmaddf_op: {
1810 union ieee754sp ft, fs, fd;
1811
1812 if (!cpu_has_mips_r6)
1813 return SIGILL;
1814
1815 MIPS_FPU_EMU_INC_STATS(maddf_s);
1816 SPFROMREG(ft, MIPSInst_FT(ir));
1817 SPFROMREG(fs, MIPSInst_FS(ir));
1818 SPFROMREG(fd, MIPSInst_FD(ir));
1819 rv.s = ieee754sp_maddf(fd, fs, ft);
1820 goto copcsr;
1821 }
1822
1823 case fmsubf_op: {
1824 union ieee754sp ft, fs, fd;
1825
1826 if (!cpu_has_mips_r6)
1827 return SIGILL;
1828
1829 MIPS_FPU_EMU_INC_STATS(msubf_s);
1830 SPFROMREG(ft, MIPSInst_FT(ir));
1831 SPFROMREG(fs, MIPSInst_FS(ir));
1832 SPFROMREG(fd, MIPSInst_FD(ir));
1833 rv.s = ieee754sp_msubf(fd, fs, ft);
1834 goto copcsr;
1835 }
1836
1837 case frint_op: {
1838 union ieee754sp fs;
1839
1840 if (!cpu_has_mips_r6)
1841 return SIGILL;
1842
1843 MIPS_FPU_EMU_INC_STATS(rint_s);
1844 SPFROMREG(fs, MIPSInst_FS(ir));
1845 rv.s = ieee754sp_rint(fs);
1846 goto copcsr;
1847 }
1848
1849 case fclass_op: {
1850 union ieee754sp fs;
1851
1852 if (!cpu_has_mips_r6)
1853 return SIGILL;
1854
1855 MIPS_FPU_EMU_INC_STATS(class_s);
1856 SPFROMREG(fs, MIPSInst_FS(ir));
1857 rv.w = ieee754sp_2008class(fs);
1858 rfmt = w_fmt;
1859 goto copcsr;
1860 }
1861
1862 case fmin_op: {
1863 union ieee754sp fs, ft;
1864
1865 if (!cpu_has_mips_r6)
1866 return SIGILL;
1867
1868 MIPS_FPU_EMU_INC_STATS(min_s);
1869 SPFROMREG(ft, MIPSInst_FT(ir));
1870 SPFROMREG(fs, MIPSInst_FS(ir));
1871 rv.s = ieee754sp_fmin(fs, ft);
1872 goto copcsr;
1873 }
1874
1875 case fmina_op: {
1876 union ieee754sp fs, ft;
1877
1878 if (!cpu_has_mips_r6)
1879 return SIGILL;
1880
1881 MIPS_FPU_EMU_INC_STATS(mina_s);
1882 SPFROMREG(ft, MIPSInst_FT(ir));
1883 SPFROMREG(fs, MIPSInst_FS(ir));
1884 rv.s = ieee754sp_fmina(fs, ft);
1885 goto copcsr;
1886 }
1887
1888 case fmax_op: {
1889 union ieee754sp fs, ft;
1890
1891 if (!cpu_has_mips_r6)
1892 return SIGILL;
1893
1894 MIPS_FPU_EMU_INC_STATS(max_s);
1895 SPFROMREG(ft, MIPSInst_FT(ir));
1896 SPFROMREG(fs, MIPSInst_FS(ir));
1897 rv.s = ieee754sp_fmax(fs, ft);
1898 goto copcsr;
1899 }
1900
1901 case fmaxa_op: {
1902 union ieee754sp fs, ft;
1903
1904 if (!cpu_has_mips_r6)
1905 return SIGILL;
1906
1907 MIPS_FPU_EMU_INC_STATS(maxa_s);
1908 SPFROMREG(ft, MIPSInst_FT(ir));
1909 SPFROMREG(fs, MIPSInst_FS(ir));
1910 rv.s = ieee754sp_fmaxa(fs, ft);
1911 goto copcsr;
1912 }
1913
1914 case fabs_op:
1915 MIPS_FPU_EMU_INC_STATS(abs_s);
1916 handler.u = ieee754sp_abs;
1917 goto scopuop;
1918
1919 case fneg_op:
1920 MIPS_FPU_EMU_INC_STATS(neg_s);
1921 handler.u = ieee754sp_neg;
1922 goto scopuop;
1923
1924 case fmov_op:
1925 /* an easy one */
1926 MIPS_FPU_EMU_INC_STATS(mov_s);
1927 SPFROMREG(rv.s, MIPSInst_FS(ir));
1928 goto copcsr;
1929
1930 /* binary op on handler */
1931scopbop:
1932 SPFROMREG(fs, MIPSInst_FS(ir));
1933 SPFROMREG(ft, MIPSInst_FT(ir));
1934
1935 rv.s = (*handler.b) (fs, ft);
1936 goto copcsr;
1937scopuop:
1938 SPFROMREG(fs, MIPSInst_FS(ir));
1939 rv.s = (*handler.u) (fs);
1940 goto copcsr;
1941copcsr:
1942 if (ieee754_cxtest(IEEE754_INEXACT)) {
1943 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1944 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1945 }
1946 if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1947 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1948 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1949 }
1950 if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1951 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1952 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1953 }
1954 if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) {
1955 MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv);
1956 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
1957 }
1958 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1959 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1960 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1961 }
1962 break;
1963
1964 /* unary conv ops */
1965 case fcvts_op:
1966 return SIGILL; /* not defined */
1967
1968 case fcvtd_op:
1969 MIPS_FPU_EMU_INC_STATS(cvt_d_s);
1970 SPFROMREG(fs, MIPSInst_FS(ir));
1971 rv.d = ieee754dp_fsp(fs);
1972 rfmt = d_fmt;
1973 goto copcsr;
1974
1975 case fcvtw_op:
1976 MIPS_FPU_EMU_INC_STATS(cvt_w_s);
1977 SPFROMREG(fs, MIPSInst_FS(ir));
1978 rv.w = ieee754sp_tint(fs);
1979 rfmt = w_fmt;
1980 goto copcsr;
1981
1982 case fround_op:
1983 case ftrunc_op:
1984 case fceil_op:
1985 case ffloor_op:
1986 if (!cpu_has_mips_2_3_4_5_r)
1987 return SIGILL;
1988
1989 if (MIPSInst_FUNC(ir) == fceil_op)
1990 MIPS_FPU_EMU_INC_STATS(ceil_w_s);
1991 if (MIPSInst_FUNC(ir) == ffloor_op)
1992 MIPS_FPU_EMU_INC_STATS(floor_w_s);
1993 if (MIPSInst_FUNC(ir) == fround_op)
1994 MIPS_FPU_EMU_INC_STATS(round_w_s);
1995 if (MIPSInst_FUNC(ir) == ftrunc_op)
1996 MIPS_FPU_EMU_INC_STATS(trunc_w_s);
1997
1998 oldrm = ieee754_csr.rm;
1999 SPFROMREG(fs, MIPSInst_FS(ir));
2000 ieee754_csr.rm = MIPSInst_FUNC(ir);
2001 rv.w = ieee754sp_tint(fs);
2002 ieee754_csr.rm = oldrm;
2003 rfmt = w_fmt;
2004 goto copcsr;
2005
2006 case fsel_op:
2007 if (!cpu_has_mips_r6)
2008 return SIGILL;
2009
2010 MIPS_FPU_EMU_INC_STATS(sel_s);
2011 SPFROMREG(fd, MIPSInst_FD(ir));
2012 if (fd.bits & 0x1)
2013 SPFROMREG(rv.s, MIPSInst_FT(ir));
2014 else
2015 SPFROMREG(rv.s, MIPSInst_FS(ir));
2016 break;
2017
2018 case fcvtl_op:
2019 if (!cpu_has_mips_3_4_5_64_r2_r6)
2020 return SIGILL;
2021
2022 MIPS_FPU_EMU_INC_STATS(cvt_l_s);
2023 SPFROMREG(fs, MIPSInst_FS(ir));
2024 rv.l = ieee754sp_tlong(fs);
2025 rfmt = l_fmt;
2026 goto copcsr;
2027
2028 case froundl_op:
2029 case ftruncl_op:
2030 case fceill_op:
2031 case ffloorl_op:
2032 if (!cpu_has_mips_3_4_5_64_r2_r6)
2033 return SIGILL;
2034
2035 if (MIPSInst_FUNC(ir) == fceill_op)
2036 MIPS_FPU_EMU_INC_STATS(ceil_l_s);
2037 if (MIPSInst_FUNC(ir) == ffloorl_op)
2038 MIPS_FPU_EMU_INC_STATS(floor_l_s);
2039 if (MIPSInst_FUNC(ir) == froundl_op)
2040 MIPS_FPU_EMU_INC_STATS(round_l_s);
2041 if (MIPSInst_FUNC(ir) == ftruncl_op)
2042 MIPS_FPU_EMU_INC_STATS(trunc_l_s);
2043
2044 oldrm = ieee754_csr.rm;
2045 SPFROMREG(fs, MIPSInst_FS(ir));
2046 ieee754_csr.rm = MIPSInst_FUNC(ir);
2047 rv.l = ieee754sp_tlong(fs);
2048 ieee754_csr.rm = oldrm;
2049 rfmt = l_fmt;
2050 goto copcsr;
2051
2052 default:
2053 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2054 unsigned int cmpop;
2055 union ieee754sp fs, ft;
2056
2057 cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2058 SPFROMREG(fs, MIPSInst_FS(ir));
2059 SPFROMREG(ft, MIPSInst_FT(ir));
2060 rv.w = ieee754sp_cmp(fs, ft,
2061 cmptab[cmpop & 0x7], cmpop & 0x8);
2062 rfmt = -1;
2063 if ((cmpop & 0x8) && ieee754_cxtest
2064 (IEEE754_INVALID_OPERATION))
2065 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2066 else
2067 goto copcsr;
2068
2069 } else
2070 return SIGILL;
2071 break;
2072 }
2073 break;
2074 }
2075
2076 case d_fmt: {
2077 union ieee754dp fd, fs, ft;
2078 union {
2079 union ieee754dp(*b) (union ieee754dp, union ieee754dp);
2080 union ieee754dp(*u) (union ieee754dp);
2081 } handler;
2082
2083 switch (MIPSInst_FUNC(ir)) {
2084 /* binary ops */
2085 case fadd_op:
2086 MIPS_FPU_EMU_INC_STATS(add_d);
2087 handler.b = ieee754dp_add;
2088 goto dcopbop;
2089 case fsub_op:
2090 MIPS_FPU_EMU_INC_STATS(sub_d);
2091 handler.b = ieee754dp_sub;
2092 goto dcopbop;
2093 case fmul_op:
2094 MIPS_FPU_EMU_INC_STATS(mul_d);
2095 handler.b = ieee754dp_mul;
2096 goto dcopbop;
2097 case fdiv_op:
2098 MIPS_FPU_EMU_INC_STATS(div_d);
2099 handler.b = ieee754dp_div;
2100 goto dcopbop;
2101
2102 /* unary ops */
2103 case fsqrt_op:
2104 if (!cpu_has_mips_2_3_4_5_r)
2105 return SIGILL;
2106
2107 MIPS_FPU_EMU_INC_STATS(sqrt_d);
2108 handler.u = ieee754dp_sqrt;
2109 goto dcopuop;
2110 /*
2111 * Note that on some MIPS IV implementations such as the
2112 * R5000 and R8000 the FSQRT and FRECIP instructions do not
2113 * achieve full IEEE-754 accuracy - however this emulator does.
2114 */
2115 case frsqrt_op:
2116 if (!cpu_has_mips_4_5_64_r2_r6)
2117 return SIGILL;
2118
2119 MIPS_FPU_EMU_INC_STATS(rsqrt_d);
2120 handler.u = fpemu_dp_rsqrt;
2121 goto dcopuop;
2122 case frecip_op:
2123 if (!cpu_has_mips_4_5_64_r2_r6)
2124 return SIGILL;
2125
2126 MIPS_FPU_EMU_INC_STATS(recip_d);
2127 handler.u = fpemu_dp_recip;
2128 goto dcopuop;
2129 case fmovc_op:
2130 if (!cpu_has_mips_4_5_r)
2131 return SIGILL;
2132
2133 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
2134 if (((ctx->fcr31 & cond) != 0) !=
2135 ((MIPSInst_FT(ir) & 1) != 0))
2136 return 0;
2137 DPFROMREG(rv.d, MIPSInst_FS(ir));
2138 break;
2139 case fmovz_op:
2140 if (!cpu_has_mips_4_5_r)
2141 return SIGILL;
2142
2143 if (xcp->regs[MIPSInst_FT(ir)] != 0)
2144 return 0;
2145 DPFROMREG(rv.d, MIPSInst_FS(ir));
2146 break;
2147 case fmovn_op:
2148 if (!cpu_has_mips_4_5_r)
2149 return SIGILL;
2150
2151 if (xcp->regs[MIPSInst_FT(ir)] == 0)
2152 return 0;
2153 DPFROMREG(rv.d, MIPSInst_FS(ir));
2154 break;
2155
2156 case fseleqz_op:
2157 if (!cpu_has_mips_r6)
2158 return SIGILL;
2159
2160 MIPS_FPU_EMU_INC_STATS(seleqz_d);
2161 DPFROMREG(rv.d, MIPSInst_FT(ir));
2162 if (rv.l & 0x1)
2163 rv.l = 0;
2164 else
2165 DPFROMREG(rv.d, MIPSInst_FS(ir));
2166 break;
2167
2168 case fselnez_op:
2169 if (!cpu_has_mips_r6)
2170 return SIGILL;
2171
2172 MIPS_FPU_EMU_INC_STATS(selnez_d);
2173 DPFROMREG(rv.d, MIPSInst_FT(ir));
2174 if (rv.l & 0x1)
2175 DPFROMREG(rv.d, MIPSInst_FS(ir));
2176 else
2177 rv.l = 0;
2178 break;
2179
2180 case fmaddf_op: {
2181 union ieee754dp ft, fs, fd;
2182
2183 if (!cpu_has_mips_r6)
2184 return SIGILL;
2185
2186 MIPS_FPU_EMU_INC_STATS(maddf_d);
2187 DPFROMREG(ft, MIPSInst_FT(ir));
2188 DPFROMREG(fs, MIPSInst_FS(ir));
2189 DPFROMREG(fd, MIPSInst_FD(ir));
2190 rv.d = ieee754dp_maddf(fd, fs, ft);
2191 goto copcsr;
2192 }
2193
2194 case fmsubf_op: {
2195 union ieee754dp ft, fs, fd;
2196
2197 if (!cpu_has_mips_r6)
2198 return SIGILL;
2199
2200 MIPS_FPU_EMU_INC_STATS(msubf_d);
2201 DPFROMREG(ft, MIPSInst_FT(ir));
2202 DPFROMREG(fs, MIPSInst_FS(ir));
2203 DPFROMREG(fd, MIPSInst_FD(ir));
2204 rv.d = ieee754dp_msubf(fd, fs, ft);
2205 goto copcsr;
2206 }
2207
2208 case frint_op: {
2209 union ieee754dp fs;
2210
2211 if (!cpu_has_mips_r6)
2212 return SIGILL;
2213
2214 MIPS_FPU_EMU_INC_STATS(rint_d);
2215 DPFROMREG(fs, MIPSInst_FS(ir));
2216 rv.d = ieee754dp_rint(fs);
2217 goto copcsr;
2218 }
2219
2220 case fclass_op: {
2221 union ieee754dp fs;
2222
2223 if (!cpu_has_mips_r6)
2224 return SIGILL;
2225
2226 MIPS_FPU_EMU_INC_STATS(class_d);
2227 DPFROMREG(fs, MIPSInst_FS(ir));
2228 rv.l = ieee754dp_2008class(fs);
2229 rfmt = l_fmt;
2230 goto copcsr;
2231 }
2232
2233 case fmin_op: {
2234 union ieee754dp fs, ft;
2235
2236 if (!cpu_has_mips_r6)
2237 return SIGILL;
2238
2239 MIPS_FPU_EMU_INC_STATS(min_d);
2240 DPFROMREG(ft, MIPSInst_FT(ir));
2241 DPFROMREG(fs, MIPSInst_FS(ir));
2242 rv.d = ieee754dp_fmin(fs, ft);
2243 goto copcsr;
2244 }
2245
2246 case fmina_op: {
2247 union ieee754dp fs, ft;
2248
2249 if (!cpu_has_mips_r6)
2250 return SIGILL;
2251
2252 MIPS_FPU_EMU_INC_STATS(mina_d);
2253 DPFROMREG(ft, MIPSInst_FT(ir));
2254 DPFROMREG(fs, MIPSInst_FS(ir));
2255 rv.d = ieee754dp_fmina(fs, ft);
2256 goto copcsr;
2257 }
2258
2259 case fmax_op: {
2260 union ieee754dp fs, ft;
2261
2262 if (!cpu_has_mips_r6)
2263 return SIGILL;
2264
2265 MIPS_FPU_EMU_INC_STATS(max_d);
2266 DPFROMREG(ft, MIPSInst_FT(ir));
2267 DPFROMREG(fs, MIPSInst_FS(ir));
2268 rv.d = ieee754dp_fmax(fs, ft);
2269 goto copcsr;
2270 }
2271
2272 case fmaxa_op: {
2273 union ieee754dp fs, ft;
2274
2275 if (!cpu_has_mips_r6)
2276 return SIGILL;
2277
2278 MIPS_FPU_EMU_INC_STATS(maxa_d);
2279 DPFROMREG(ft, MIPSInst_FT(ir));
2280 DPFROMREG(fs, MIPSInst_FS(ir));
2281 rv.d = ieee754dp_fmaxa(fs, ft);
2282 goto copcsr;
2283 }
2284
2285 case fabs_op:
2286 MIPS_FPU_EMU_INC_STATS(abs_d);
2287 handler.u = ieee754dp_abs;
2288 goto dcopuop;
2289
2290 case fneg_op:
2291 MIPS_FPU_EMU_INC_STATS(neg_d);
2292 handler.u = ieee754dp_neg;
2293 goto dcopuop;
2294
2295 case fmov_op:
2296 /* an easy one */
2297 MIPS_FPU_EMU_INC_STATS(mov_d);
2298 DPFROMREG(rv.d, MIPSInst_FS(ir));
2299 goto copcsr;
2300
2301 /* binary op on handler */
2302dcopbop:
2303 DPFROMREG(fs, MIPSInst_FS(ir));
2304 DPFROMREG(ft, MIPSInst_FT(ir));
2305
2306 rv.d = (*handler.b) (fs, ft);
2307 goto copcsr;
2308dcopuop:
2309 DPFROMREG(fs, MIPSInst_FS(ir));
2310 rv.d = (*handler.u) (fs);
2311 goto copcsr;
2312
2313 /*
2314 * unary conv ops
2315 */
2316 case fcvts_op:
2317 MIPS_FPU_EMU_INC_STATS(cvt_s_d);
2318 DPFROMREG(fs, MIPSInst_FS(ir));
2319 rv.s = ieee754sp_fdp(fs);
2320 rfmt = s_fmt;
2321 goto copcsr;
2322
2323 case fcvtd_op:
2324 return SIGILL; /* not defined */
2325
2326 case fcvtw_op:
2327 MIPS_FPU_EMU_INC_STATS(cvt_w_d);
2328 DPFROMREG(fs, MIPSInst_FS(ir));
2329 rv.w = ieee754dp_tint(fs); /* wrong */
2330 rfmt = w_fmt;
2331 goto copcsr;
2332
2333 case fround_op:
2334 case ftrunc_op:
2335 case fceil_op:
2336 case ffloor_op:
2337 if (!cpu_has_mips_2_3_4_5_r)
2338 return SIGILL;
2339
2340 if (MIPSInst_FUNC(ir) == fceil_op)
2341 MIPS_FPU_EMU_INC_STATS(ceil_w_d);
2342 if (MIPSInst_FUNC(ir) == ffloor_op)
2343 MIPS_FPU_EMU_INC_STATS(floor_w_d);
2344 if (MIPSInst_FUNC(ir) == fround_op)
2345 MIPS_FPU_EMU_INC_STATS(round_w_d);
2346 if (MIPSInst_FUNC(ir) == ftrunc_op)
2347 MIPS_FPU_EMU_INC_STATS(trunc_w_d);
2348
2349 oldrm = ieee754_csr.rm;
2350 DPFROMREG(fs, MIPSInst_FS(ir));
2351 ieee754_csr.rm = MIPSInst_FUNC(ir);
2352 rv.w = ieee754dp_tint(fs);
2353 ieee754_csr.rm = oldrm;
2354 rfmt = w_fmt;
2355 goto copcsr;
2356
2357 case fsel_op:
2358 if (!cpu_has_mips_r6)
2359 return SIGILL;
2360
2361 MIPS_FPU_EMU_INC_STATS(sel_d);
2362 DPFROMREG(fd, MIPSInst_FD(ir));
2363 if (fd.bits & 0x1)
2364 DPFROMREG(rv.d, MIPSInst_FT(ir));
2365 else
2366 DPFROMREG(rv.d, MIPSInst_FS(ir));
2367 break;
2368
2369 case fcvtl_op:
2370 if (!cpu_has_mips_3_4_5_64_r2_r6)
2371 return SIGILL;
2372
2373 MIPS_FPU_EMU_INC_STATS(cvt_l_d);
2374 DPFROMREG(fs, MIPSInst_FS(ir));
2375 rv.l = ieee754dp_tlong(fs);
2376 rfmt = l_fmt;
2377 goto copcsr;
2378
2379 case froundl_op:
2380 case ftruncl_op:
2381 case fceill_op:
2382 case ffloorl_op:
2383 if (!cpu_has_mips_3_4_5_64_r2_r6)
2384 return SIGILL;
2385
2386 if (MIPSInst_FUNC(ir) == fceill_op)
2387 MIPS_FPU_EMU_INC_STATS(ceil_l_d);
2388 if (MIPSInst_FUNC(ir) == ffloorl_op)
2389 MIPS_FPU_EMU_INC_STATS(floor_l_d);
2390 if (MIPSInst_FUNC(ir) == froundl_op)
2391 MIPS_FPU_EMU_INC_STATS(round_l_d);
2392 if (MIPSInst_FUNC(ir) == ftruncl_op)
2393 MIPS_FPU_EMU_INC_STATS(trunc_l_d);
2394
2395 oldrm = ieee754_csr.rm;
2396 DPFROMREG(fs, MIPSInst_FS(ir));
2397 ieee754_csr.rm = MIPSInst_FUNC(ir);
2398 rv.l = ieee754dp_tlong(fs);
2399 ieee754_csr.rm = oldrm;
2400 rfmt = l_fmt;
2401 goto copcsr;
2402
2403 default:
2404 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2405 unsigned int cmpop;
2406 union ieee754dp fs, ft;
2407
2408 cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2409 DPFROMREG(fs, MIPSInst_FS(ir));
2410 DPFROMREG(ft, MIPSInst_FT(ir));
2411 rv.w = ieee754dp_cmp(fs, ft,
2412 cmptab[cmpop & 0x7], cmpop & 0x8);
2413 rfmt = -1;
2414 if ((cmpop & 0x8)
2415 &&
2416 ieee754_cxtest
2417 (IEEE754_INVALID_OPERATION))
2418 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2419 else
2420 goto copcsr;
2421
2422 }
2423 else {
2424 return SIGILL;
2425 }
2426 break;
2427 }
2428 break;
2429 }
2430
2431 case w_fmt: {
2432 union ieee754dp fs;
2433
2434 switch (MIPSInst_FUNC(ir)) {
2435 case fcvts_op:
2436 /* convert word to single precision real */
2437 MIPS_FPU_EMU_INC_STATS(cvt_s_w);
2438 SPFROMREG(fs, MIPSInst_FS(ir));
2439 rv.s = ieee754sp_fint(fs.bits);
2440 rfmt = s_fmt;
2441 goto copcsr;
2442 case fcvtd_op:
2443 /* convert word to double precision real */
2444 MIPS_FPU_EMU_INC_STATS(cvt_d_w);
2445 SPFROMREG(fs, MIPSInst_FS(ir));
2446 rv.d = ieee754dp_fint(fs.bits);
2447 rfmt = d_fmt;
2448 goto copcsr;
2449 default: {
2450 /* Emulating the new CMP.condn.fmt R6 instruction */
2451#define CMPOP_MASK 0x7
2452#define SIGN_BIT (0x1 << 3)
2453#define PREDICATE_BIT (0x1 << 4)
2454
2455 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2456 int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2457 union ieee754sp fs, ft;
2458
2459 /* This is an R6 only instruction */
2460 if (!cpu_has_mips_r6 ||
2461 (MIPSInst_FUNC(ir) & 0x20))
2462 return SIGILL;
2463
2464 if (!sig) {
2465 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2466 switch (cmpop) {
2467 case 0:
2468 MIPS_FPU_EMU_INC_STATS(cmp_af_s);
2469 break;
2470 case 1:
2471 MIPS_FPU_EMU_INC_STATS(cmp_un_s);
2472 break;
2473 case 2:
2474 MIPS_FPU_EMU_INC_STATS(cmp_eq_s);
2475 break;
2476 case 3:
2477 MIPS_FPU_EMU_INC_STATS(cmp_ueq_s);
2478 break;
2479 case 4:
2480 MIPS_FPU_EMU_INC_STATS(cmp_lt_s);
2481 break;
2482 case 5:
2483 MIPS_FPU_EMU_INC_STATS(cmp_ult_s);
2484 break;
2485 case 6:
2486 MIPS_FPU_EMU_INC_STATS(cmp_le_s);
2487 break;
2488 case 7:
2489 MIPS_FPU_EMU_INC_STATS(cmp_ule_s);
2490 break;
2491 }
2492 } else {
2493 switch (cmpop) {
2494 case 1:
2495 MIPS_FPU_EMU_INC_STATS(cmp_or_s);
2496 break;
2497 case 2:
2498 MIPS_FPU_EMU_INC_STATS(cmp_une_s);
2499 break;
2500 case 3:
2501 MIPS_FPU_EMU_INC_STATS(cmp_ne_s);
2502 break;
2503 }
2504 }
2505 } else {
2506 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2507 switch (cmpop) {
2508 case 0:
2509 MIPS_FPU_EMU_INC_STATS(cmp_saf_s);
2510 break;
2511 case 1:
2512 MIPS_FPU_EMU_INC_STATS(cmp_sun_s);
2513 break;
2514 case 2:
2515 MIPS_FPU_EMU_INC_STATS(cmp_seq_s);
2516 break;
2517 case 3:
2518 MIPS_FPU_EMU_INC_STATS(cmp_sueq_s);
2519 break;
2520 case 4:
2521 MIPS_FPU_EMU_INC_STATS(cmp_slt_s);
2522 break;
2523 case 5:
2524 MIPS_FPU_EMU_INC_STATS(cmp_sult_s);
2525 break;
2526 case 6:
2527 MIPS_FPU_EMU_INC_STATS(cmp_sle_s);
2528 break;
2529 case 7:
2530 MIPS_FPU_EMU_INC_STATS(cmp_sule_s);
2531 break;
2532 }
2533 } else {
2534 switch (cmpop) {
2535 case 1:
2536 MIPS_FPU_EMU_INC_STATS(cmp_sor_s);
2537 break;
2538 case 2:
2539 MIPS_FPU_EMU_INC_STATS(cmp_sune_s);
2540 break;
2541 case 3:
2542 MIPS_FPU_EMU_INC_STATS(cmp_sne_s);
2543 break;
2544 }
2545 }
2546 }
2547
2548 /* fmt is w_fmt for single precision so fix it */
2549 rfmt = s_fmt;
2550 /* default to false */
2551 rv.w = 0;
2552
2553 /* CMP.condn.S */
2554 SPFROMREG(fs, MIPSInst_FS(ir));
2555 SPFROMREG(ft, MIPSInst_FT(ir));
2556
2557 /* positive predicates */
2558 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2559 if (ieee754sp_cmp(fs, ft, cmptab[cmpop],
2560 sig))
2561 rv.w = -1; /* true, all 1s */
2562 if ((sig) &&
2563 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2564 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2565 else
2566 goto copcsr;
2567 } else {
2568 /* negative predicates */
2569 switch (cmpop) {
2570 case 1:
2571 case 2:
2572 case 3:
2573 if (ieee754sp_cmp(fs, ft,
2574 negative_cmptab[cmpop],
2575 sig))
2576 rv.w = -1; /* true, all 1s */
2577 if (sig &&
2578 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2579 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2580 else
2581 goto copcsr;
2582 break;
2583 default:
2584 /* Reserved R6 ops */
2585 return SIGILL;
2586 }
2587 }
2588 break;
2589 }
2590 }
2591 break;
2592 }
2593
2594 case l_fmt:
2595
2596 if (!cpu_has_mips_3_4_5_64_r2_r6)
2597 return SIGILL;
2598
2599 DIFROMREG(bits, MIPSInst_FS(ir));
2600
2601 switch (MIPSInst_FUNC(ir)) {
2602 case fcvts_op:
2603 /* convert long to single precision real */
2604 MIPS_FPU_EMU_INC_STATS(cvt_s_l);
2605 rv.s = ieee754sp_flong(bits);
2606 rfmt = s_fmt;
2607 goto copcsr;
2608 case fcvtd_op:
2609 /* convert long to double precision real */
2610 MIPS_FPU_EMU_INC_STATS(cvt_d_l);
2611 rv.d = ieee754dp_flong(bits);
2612 rfmt = d_fmt;
2613 goto copcsr;
2614 default: {
2615 /* Emulating the new CMP.condn.fmt R6 instruction */
2616 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2617 int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2618 union ieee754dp fs, ft;
2619
2620 if (!cpu_has_mips_r6 ||
2621 (MIPSInst_FUNC(ir) & 0x20))
2622 return SIGILL;
2623
2624 if (!sig) {
2625 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2626 switch (cmpop) {
2627 case 0:
2628 MIPS_FPU_EMU_INC_STATS(cmp_af_d);
2629 break;
2630 case 1:
2631 MIPS_FPU_EMU_INC_STATS(cmp_un_d);
2632 break;
2633 case 2:
2634 MIPS_FPU_EMU_INC_STATS(cmp_eq_d);
2635 break;
2636 case 3:
2637 MIPS_FPU_EMU_INC_STATS(cmp_ueq_d);
2638 break;
2639 case 4:
2640 MIPS_FPU_EMU_INC_STATS(cmp_lt_d);
2641 break;
2642 case 5:
2643 MIPS_FPU_EMU_INC_STATS(cmp_ult_d);
2644 break;
2645 case 6:
2646 MIPS_FPU_EMU_INC_STATS(cmp_le_d);
2647 break;
2648 case 7:
2649 MIPS_FPU_EMU_INC_STATS(cmp_ule_d);
2650 break;
2651 }
2652 } else {
2653 switch (cmpop) {
2654 case 1:
2655 MIPS_FPU_EMU_INC_STATS(cmp_or_d);
2656 break;
2657 case 2:
2658 MIPS_FPU_EMU_INC_STATS(cmp_une_d);
2659 break;
2660 case 3:
2661 MIPS_FPU_EMU_INC_STATS(cmp_ne_d);
2662 break;
2663 }
2664 }
2665 } else {
2666 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2667 switch (cmpop) {
2668 case 0:
2669 MIPS_FPU_EMU_INC_STATS(cmp_saf_d);
2670 break;
2671 case 1:
2672 MIPS_FPU_EMU_INC_STATS(cmp_sun_d);
2673 break;
2674 case 2:
2675 MIPS_FPU_EMU_INC_STATS(cmp_seq_d);
2676 break;
2677 case 3:
2678 MIPS_FPU_EMU_INC_STATS(cmp_sueq_d);
2679 break;
2680 case 4:
2681 MIPS_FPU_EMU_INC_STATS(cmp_slt_d);
2682 break;
2683 case 5:
2684 MIPS_FPU_EMU_INC_STATS(cmp_sult_d);
2685 break;
2686 case 6:
2687 MIPS_FPU_EMU_INC_STATS(cmp_sle_d);
2688 break;
2689 case 7:
2690 MIPS_FPU_EMU_INC_STATS(cmp_sule_d);
2691 break;
2692 }
2693 } else {
2694 switch (cmpop) {
2695 case 1:
2696 MIPS_FPU_EMU_INC_STATS(cmp_sor_d);
2697 break;
2698 case 2:
2699 MIPS_FPU_EMU_INC_STATS(cmp_sune_d);
2700 break;
2701 case 3:
2702 MIPS_FPU_EMU_INC_STATS(cmp_sne_d);
2703 break;
2704 }
2705 }
2706 }
2707
2708 /* fmt is l_fmt for double precision so fix it */
2709 rfmt = d_fmt;
2710 /* default to false */
2711 rv.l = 0;
2712
2713 /* CMP.condn.D */
2714 DPFROMREG(fs, MIPSInst_FS(ir));
2715 DPFROMREG(ft, MIPSInst_FT(ir));
2716
2717 /* positive predicates */
2718 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2719 if (ieee754dp_cmp(fs, ft,
2720 cmptab[cmpop], sig))
2721 rv.l = -1LL; /* true, all 1s */
2722 if (sig &&
2723 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2724 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2725 else
2726 goto copcsr;
2727 } else {
2728 /* negative predicates */
2729 switch (cmpop) {
2730 case 1:
2731 case 2:
2732 case 3:
2733 if (ieee754dp_cmp(fs, ft,
2734 negative_cmptab[cmpop],
2735 sig))
2736 rv.l = -1LL; /* true, all 1s */
2737 if (sig &&
2738 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2739 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2740 else
2741 goto copcsr;
2742 break;
2743 default:
2744 /* Reserved R6 ops */
2745 return SIGILL;
2746 }
2747 }
2748 break;
2749 }
2750 }
2751 break;
2752
2753 default:
2754 return SIGILL;
2755 }
2756
2757 /*
2758 * Update the fpu CSR register for this operation.
2759 * If an exception is required, generate a tidy SIGFPE exception,
2760 * without updating the result register.
2761 * Note: cause exception bits do not accumulate, they are rewritten
2762 * for each op; only the flag/sticky bits accumulate.
2763 */
2764 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
2765 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
2766 /*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */
2767 return SIGFPE;
2768 }
2769
2770 /*
2771 * Now we can safely write the result back to the register file.
2772 */
2773 switch (rfmt) {
2774 case -1:
2775
2776 if (cpu_has_mips_4_5_r)
2777 cbit = fpucondbit[MIPSInst_FD(ir) >> 2];
2778 else
2779 cbit = FPU_CSR_COND;
2780 if (rv.w)
2781 ctx->fcr31 |= cbit;
2782 else
2783 ctx->fcr31 &= ~cbit;
2784 break;
2785
2786 case d_fmt:
2787 DPTOREG(rv.d, MIPSInst_FD(ir));
2788 break;
2789 case s_fmt:
2790 SPTOREG(rv.s, MIPSInst_FD(ir));
2791 break;
2792 case w_fmt:
2793 SITOREG(rv.w, MIPSInst_FD(ir));
2794 break;
2795 case l_fmt:
2796 if (!cpu_has_mips_3_4_5_64_r2_r6)
2797 return SIGILL;
2798
2799 DITOREG(rv.l, MIPSInst_FD(ir));
2800 break;
2801 default:
2802 return SIGILL;
2803 }
2804
2805 return 0;
2806}
2807
2808/*
2809 * Emulate FPU instructions.
2810 *
2811 * If we use FPU hardware, then we have been typically called to handle
2812 * an unimplemented operation, such as where an operand is a NaN or
2813 * denormalized. In that case exit the emulation loop after a single
2814 * iteration so as to let hardware execute any subsequent instructions.
2815 *
2816 * If we have no FPU hardware or it has been disabled, then continue
2817 * emulating floating-point instructions until one of these conditions
2818 * has occurred:
2819 *
2820 * - a non-FPU instruction has been encountered,
2821 *
2822 * - an attempt to emulate has ended with a signal,
2823 *
2824 * - the ISA mode has been switched.
2825 *
2826 * We need to terminate the emulation loop if we got switched to the
2827 * MIPS16 mode, whether supported or not, so that we do not attempt
2828 * to emulate a MIPS16 instruction as a regular MIPS FPU instruction.
2829 * Similarly if we got switched to the microMIPS mode and only the
2830 * regular MIPS mode is supported, so that we do not attempt to emulate
2831 * a microMIPS instruction as a regular MIPS FPU instruction. Or if
2832 * we got switched to the regular MIPS mode and only the microMIPS mode
2833 * is supported, so that we do not attempt to emulate a regular MIPS
2834 * instruction that should cause an Address Error exception instead.
2835 * For simplicity we always terminate upon an ISA mode switch.
2836 */
2837int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
2838 int has_fpu, void __user **fault_addr)
2839{
2840 unsigned long oldepc, prevepc;
2841 struct mm_decoded_insn dec_insn;
2842 u16 instr[4];
2843 u16 *instr_ptr;
2844 int sig = 0;
2845
2846 /*
2847 * Initialize context if it hasn't been used already, otherwise ensure
2848 * it has been saved to struct thread_struct.
2849 */
2850 if (!init_fp_ctx(current))
2851 lose_fpu(1);
2852
2853 oldepc = xcp->cp0_epc;
2854 do {
2855 prevepc = xcp->cp0_epc;
2856
2857 if (get_isa16_mode(prevepc) && cpu_has_mmips) {
2858 /*
2859 * Get next 2 microMIPS instructions and convert them
2860 * into 32-bit instructions.
2861 */
2862 if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
2863 (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
2864 (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
2865 (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
2866 MIPS_FPU_EMU_INC_STATS(errors);
2867 return SIGBUS;
2868 }
2869 instr_ptr = instr;
2870
2871 /* Get first instruction. */
2872 if (mm_insn_16bit(*instr_ptr)) {
2873 /* Duplicate the half-word. */
2874 dec_insn.insn = (*instr_ptr << 16) |
2875 (*instr_ptr);
2876 /* 16-bit instruction. */
2877 dec_insn.pc_inc = 2;
2878 instr_ptr += 1;
2879 } else {
2880 dec_insn.insn = (*instr_ptr << 16) |
2881 *(instr_ptr+1);
2882 /* 32-bit instruction. */
2883 dec_insn.pc_inc = 4;
2884 instr_ptr += 2;
2885 }
2886 /* Get second instruction. */
2887 if (mm_insn_16bit(*instr_ptr)) {
2888 /* Duplicate the half-word. */
2889 dec_insn.next_insn = (*instr_ptr << 16) |
2890 (*instr_ptr);
2891 /* 16-bit instruction. */
2892 dec_insn.next_pc_inc = 2;
2893 } else {
2894 dec_insn.next_insn = (*instr_ptr << 16) |
2895 *(instr_ptr+1);
2896 /* 32-bit instruction. */
2897 dec_insn.next_pc_inc = 4;
2898 }
2899 dec_insn.micro_mips_mode = 1;
2900 } else {
2901 if ((get_user(dec_insn.insn,
2902 (mips_instruction __user *) xcp->cp0_epc)) ||
2903 (get_user(dec_insn.next_insn,
2904 (mips_instruction __user *)(xcp->cp0_epc+4)))) {
2905 MIPS_FPU_EMU_INC_STATS(errors);
2906 return SIGBUS;
2907 }
2908 dec_insn.pc_inc = 4;
2909 dec_insn.next_pc_inc = 4;
2910 dec_insn.micro_mips_mode = 0;
2911 }
2912
2913 if ((dec_insn.insn == 0) ||
2914 ((dec_insn.pc_inc == 2) &&
2915 ((dec_insn.insn & 0xffff) == MM_NOP16)))
2916 xcp->cp0_epc += dec_insn.pc_inc; /* Skip NOPs */
2917 else {
2918 /*
2919 * The 'ieee754_csr' is an alias of ctx->fcr31.
2920 * No need to copy ctx->fcr31 to ieee754_csr.
2921 */
2922 sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
2923 }
2924
2925 if (has_fpu)
2926 break;
2927 if (sig)
2928 break;
2929 /*
2930 * We have to check for the ISA bit explicitly here,
2931 * because `get_isa16_mode' may return 0 if support
2932 * for code compression has been globally disabled,
2933 * or otherwise we may produce the wrong signal or
2934 * even proceed successfully where we must not.
2935 */
2936 if ((xcp->cp0_epc ^ prevepc) & 0x1)
2937 break;
2938
2939 cond_resched();
2940 } while (xcp->cp0_epc > prevepc);
2941
2942 /* SIGILL indicates a non-fpu instruction */
2943 if (sig == SIGILL && xcp->cp0_epc != oldepc)
2944 /* but if EPC has advanced, then ignore it */
2945 sig = 0;
2946
2947 return sig;
2948}