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MIPS: math-emu: Add support for the MIPS R6 SELNEZ FPU instruction
[deliverable/linux.git] / arch / mips / math-emu / cp1emu.c
1 /*
2 * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator
3 *
4 * MIPS floating point support
5 * Copyright (C) 1994-2000 Algorithmics Ltd.
6 *
7 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
8 * Copyright (C) 2000 MIPS Technologies, Inc.
9 *
10 * This program is free software; you can distribute it and/or modify it
11 * under the terms of the GNU General Public License (Version 2) as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 * for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
22 *
23 * A complete emulator for MIPS coprocessor 1 instructions. This is
24 * required for #float(switch) or #float(trap), where it catches all
25 * COP1 instructions via the "CoProcessor Unusable" exception.
26 *
27 * More surprisingly it is also required for #float(ieee), to help out
28 * the hardware FPU at the boundaries of the IEEE-754 representation
29 * (denormalised values, infinities, underflow, etc). It is made
30 * quite nasty because emulation of some non-COP1 instructions is
31 * required, e.g. in branch delay slots.
32 *
33 * Note if you know that you won't have an FPU, then you'll get much
34 * better performance by compiling with -msoft-float!
35 */
36 #include <linux/sched.h>
37 #include <linux/debugfs.h>
38 #include <linux/kconfig.h>
39 #include <linux/percpu-defs.h>
40 #include <linux/perf_event.h>
41
42 #include <asm/branch.h>
43 #include <asm/inst.h>
44 #include <asm/ptrace.h>
45 #include <asm/signal.h>
46 #include <asm/uaccess.h>
47
48 #include <asm/cpu-info.h>
49 #include <asm/processor.h>
50 #include <asm/fpu_emulator.h>
51 #include <asm/fpu.h>
52 #include <asm/mips-r2-to-r6-emul.h>
53
54 #include "ieee754.h"
55
56 /* Function which emulates a floating point instruction. */
57
58 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
59 mips_instruction);
60
61 static int fpux_emu(struct pt_regs *,
62 struct mips_fpu_struct *, mips_instruction, void *__user *);
63
64 /* Control registers */
65
66 #define FPCREG_RID 0 /* $0 = revision id */
67 #define FPCREG_FCCR 25 /* $25 = fccr */
68 #define FPCREG_FEXR 26 /* $26 = fexr */
69 #define FPCREG_FENR 28 /* $28 = fenr */
70 #define FPCREG_CSR 31 /* $31 = csr */
71
72 /* convert condition code register number to csr bit */
73 const unsigned int fpucondbit[8] = {
74 FPU_CSR_COND,
75 FPU_CSR_COND1,
76 FPU_CSR_COND2,
77 FPU_CSR_COND3,
78 FPU_CSR_COND4,
79 FPU_CSR_COND5,
80 FPU_CSR_COND6,
81 FPU_CSR_COND7
82 };
83
84 /* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
85 static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
86 static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
87 static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
88 static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
89
90 /*
91 * This functions translates a 32-bit microMIPS instruction
92 * into a 32-bit MIPS32 instruction. Returns 0 on success
93 * and SIGILL otherwise.
94 */
95 static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
96 {
97 union mips_instruction insn = *insn_ptr;
98 union mips_instruction mips32_insn = insn;
99 int func, fmt, op;
100
101 switch (insn.mm_i_format.opcode) {
102 case mm_ldc132_op:
103 mips32_insn.mm_i_format.opcode = ldc1_op;
104 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
105 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
106 break;
107 case mm_lwc132_op:
108 mips32_insn.mm_i_format.opcode = lwc1_op;
109 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
110 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
111 break;
112 case mm_sdc132_op:
113 mips32_insn.mm_i_format.opcode = sdc1_op;
114 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
115 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
116 break;
117 case mm_swc132_op:
118 mips32_insn.mm_i_format.opcode = swc1_op;
119 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
120 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
121 break;
122 case mm_pool32i_op:
123 /* NOTE: offset is << by 1 if in microMIPS mode. */
124 if ((insn.mm_i_format.rt == mm_bc1f_op) ||
125 (insn.mm_i_format.rt == mm_bc1t_op)) {
126 mips32_insn.fb_format.opcode = cop1_op;
127 mips32_insn.fb_format.bc = bc_op;
128 mips32_insn.fb_format.flag =
129 (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
130 } else
131 return SIGILL;
132 break;
133 case mm_pool32f_op:
134 switch (insn.mm_fp0_format.func) {
135 case mm_32f_01_op:
136 case mm_32f_11_op:
137 case mm_32f_02_op:
138 case mm_32f_12_op:
139 case mm_32f_41_op:
140 case mm_32f_51_op:
141 case mm_32f_42_op:
142 case mm_32f_52_op:
143 op = insn.mm_fp0_format.func;
144 if (op == mm_32f_01_op)
145 func = madd_s_op;
146 else if (op == mm_32f_11_op)
147 func = madd_d_op;
148 else if (op == mm_32f_02_op)
149 func = nmadd_s_op;
150 else if (op == mm_32f_12_op)
151 func = nmadd_d_op;
152 else if (op == mm_32f_41_op)
153 func = msub_s_op;
154 else if (op == mm_32f_51_op)
155 func = msub_d_op;
156 else if (op == mm_32f_42_op)
157 func = nmsub_s_op;
158 else
159 func = nmsub_d_op;
160 mips32_insn.fp6_format.opcode = cop1x_op;
161 mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
162 mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
163 mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
164 mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
165 mips32_insn.fp6_format.func = func;
166 break;
167 case mm_32f_10_op:
168 func = -1; /* Invalid */
169 op = insn.mm_fp5_format.op & 0x7;
170 if (op == mm_ldxc1_op)
171 func = ldxc1_op;
172 else if (op == mm_sdxc1_op)
173 func = sdxc1_op;
174 else if (op == mm_lwxc1_op)
175 func = lwxc1_op;
176 else if (op == mm_swxc1_op)
177 func = swxc1_op;
178
179 if (func != -1) {
180 mips32_insn.r_format.opcode = cop1x_op;
181 mips32_insn.r_format.rs =
182 insn.mm_fp5_format.base;
183 mips32_insn.r_format.rt =
184 insn.mm_fp5_format.index;
185 mips32_insn.r_format.rd = 0;
186 mips32_insn.r_format.re = insn.mm_fp5_format.fd;
187 mips32_insn.r_format.func = func;
188 } else
189 return SIGILL;
190 break;
191 case mm_32f_40_op:
192 op = -1; /* Invalid */
193 if (insn.mm_fp2_format.op == mm_fmovt_op)
194 op = 1;
195 else if (insn.mm_fp2_format.op == mm_fmovf_op)
196 op = 0;
197 if (op != -1) {
198 mips32_insn.fp0_format.opcode = cop1_op;
199 mips32_insn.fp0_format.fmt =
200 sdps_format[insn.mm_fp2_format.fmt];
201 mips32_insn.fp0_format.ft =
202 (insn.mm_fp2_format.cc<<2) + op;
203 mips32_insn.fp0_format.fs =
204 insn.mm_fp2_format.fs;
205 mips32_insn.fp0_format.fd =
206 insn.mm_fp2_format.fd;
207 mips32_insn.fp0_format.func = fmovc_op;
208 } else
209 return SIGILL;
210 break;
211 case mm_32f_60_op:
212 func = -1; /* Invalid */
213 if (insn.mm_fp0_format.op == mm_fadd_op)
214 func = fadd_op;
215 else if (insn.mm_fp0_format.op == mm_fsub_op)
216 func = fsub_op;
217 else if (insn.mm_fp0_format.op == mm_fmul_op)
218 func = fmul_op;
219 else if (insn.mm_fp0_format.op == mm_fdiv_op)
220 func = fdiv_op;
221 if (func != -1) {
222 mips32_insn.fp0_format.opcode = cop1_op;
223 mips32_insn.fp0_format.fmt =
224 sdps_format[insn.mm_fp0_format.fmt];
225 mips32_insn.fp0_format.ft =
226 insn.mm_fp0_format.ft;
227 mips32_insn.fp0_format.fs =
228 insn.mm_fp0_format.fs;
229 mips32_insn.fp0_format.fd =
230 insn.mm_fp0_format.fd;
231 mips32_insn.fp0_format.func = func;
232 } else
233 return SIGILL;
234 break;
235 case mm_32f_70_op:
236 func = -1; /* Invalid */
237 if (insn.mm_fp0_format.op == mm_fmovn_op)
238 func = fmovn_op;
239 else if (insn.mm_fp0_format.op == mm_fmovz_op)
240 func = fmovz_op;
241 if (func != -1) {
242 mips32_insn.fp0_format.opcode = cop1_op;
243 mips32_insn.fp0_format.fmt =
244 sdps_format[insn.mm_fp0_format.fmt];
245 mips32_insn.fp0_format.ft =
246 insn.mm_fp0_format.ft;
247 mips32_insn.fp0_format.fs =
248 insn.mm_fp0_format.fs;
249 mips32_insn.fp0_format.fd =
250 insn.mm_fp0_format.fd;
251 mips32_insn.fp0_format.func = func;
252 } else
253 return SIGILL;
254 break;
255 case mm_32f_73_op: /* POOL32FXF */
256 switch (insn.mm_fp1_format.op) {
257 case mm_movf0_op:
258 case mm_movf1_op:
259 case mm_movt0_op:
260 case mm_movt1_op:
261 if ((insn.mm_fp1_format.op & 0x7f) ==
262 mm_movf0_op)
263 op = 0;
264 else
265 op = 1;
266 mips32_insn.r_format.opcode = spec_op;
267 mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
268 mips32_insn.r_format.rt =
269 (insn.mm_fp4_format.cc << 2) + op;
270 mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
271 mips32_insn.r_format.re = 0;
272 mips32_insn.r_format.func = movc_op;
273 break;
274 case mm_fcvtd0_op:
275 case mm_fcvtd1_op:
276 case mm_fcvts0_op:
277 case mm_fcvts1_op:
278 if ((insn.mm_fp1_format.op & 0x7f) ==
279 mm_fcvtd0_op) {
280 func = fcvtd_op;
281 fmt = swl_format[insn.mm_fp3_format.fmt];
282 } else {
283 func = fcvts_op;
284 fmt = dwl_format[insn.mm_fp3_format.fmt];
285 }
286 mips32_insn.fp0_format.opcode = cop1_op;
287 mips32_insn.fp0_format.fmt = fmt;
288 mips32_insn.fp0_format.ft = 0;
289 mips32_insn.fp0_format.fs =
290 insn.mm_fp3_format.fs;
291 mips32_insn.fp0_format.fd =
292 insn.mm_fp3_format.rt;
293 mips32_insn.fp0_format.func = func;
294 break;
295 case mm_fmov0_op:
296 case mm_fmov1_op:
297 case mm_fabs0_op:
298 case mm_fabs1_op:
299 case mm_fneg0_op:
300 case mm_fneg1_op:
301 if ((insn.mm_fp1_format.op & 0x7f) ==
302 mm_fmov0_op)
303 func = fmov_op;
304 else if ((insn.mm_fp1_format.op & 0x7f) ==
305 mm_fabs0_op)
306 func = fabs_op;
307 else
308 func = fneg_op;
309 mips32_insn.fp0_format.opcode = cop1_op;
310 mips32_insn.fp0_format.fmt =
311 sdps_format[insn.mm_fp3_format.fmt];
312 mips32_insn.fp0_format.ft = 0;
313 mips32_insn.fp0_format.fs =
314 insn.mm_fp3_format.fs;
315 mips32_insn.fp0_format.fd =
316 insn.mm_fp3_format.rt;
317 mips32_insn.fp0_format.func = func;
318 break;
319 case mm_ffloorl_op:
320 case mm_ffloorw_op:
321 case mm_fceill_op:
322 case mm_fceilw_op:
323 case mm_ftruncl_op:
324 case mm_ftruncw_op:
325 case mm_froundl_op:
326 case mm_froundw_op:
327 case mm_fcvtl_op:
328 case mm_fcvtw_op:
329 if (insn.mm_fp1_format.op == mm_ffloorl_op)
330 func = ffloorl_op;
331 else if (insn.mm_fp1_format.op == mm_ffloorw_op)
332 func = ffloor_op;
333 else if (insn.mm_fp1_format.op == mm_fceill_op)
334 func = fceill_op;
335 else if (insn.mm_fp1_format.op == mm_fceilw_op)
336 func = fceil_op;
337 else if (insn.mm_fp1_format.op == mm_ftruncl_op)
338 func = ftruncl_op;
339 else if (insn.mm_fp1_format.op == mm_ftruncw_op)
340 func = ftrunc_op;
341 else if (insn.mm_fp1_format.op == mm_froundl_op)
342 func = froundl_op;
343 else if (insn.mm_fp1_format.op == mm_froundw_op)
344 func = fround_op;
345 else if (insn.mm_fp1_format.op == mm_fcvtl_op)
346 func = fcvtl_op;
347 else
348 func = fcvtw_op;
349 mips32_insn.fp0_format.opcode = cop1_op;
350 mips32_insn.fp0_format.fmt =
351 sd_format[insn.mm_fp1_format.fmt];
352 mips32_insn.fp0_format.ft = 0;
353 mips32_insn.fp0_format.fs =
354 insn.mm_fp1_format.fs;
355 mips32_insn.fp0_format.fd =
356 insn.mm_fp1_format.rt;
357 mips32_insn.fp0_format.func = func;
358 break;
359 case mm_frsqrt_op:
360 case mm_fsqrt_op:
361 case mm_frecip_op:
362 if (insn.mm_fp1_format.op == mm_frsqrt_op)
363 func = frsqrt_op;
364 else if (insn.mm_fp1_format.op == mm_fsqrt_op)
365 func = fsqrt_op;
366 else
367 func = frecip_op;
368 mips32_insn.fp0_format.opcode = cop1_op;
369 mips32_insn.fp0_format.fmt =
370 sdps_format[insn.mm_fp1_format.fmt];
371 mips32_insn.fp0_format.ft = 0;
372 mips32_insn.fp0_format.fs =
373 insn.mm_fp1_format.fs;
374 mips32_insn.fp0_format.fd =
375 insn.mm_fp1_format.rt;
376 mips32_insn.fp0_format.func = func;
377 break;
378 case mm_mfc1_op:
379 case mm_mtc1_op:
380 case mm_cfc1_op:
381 case mm_ctc1_op:
382 case mm_mfhc1_op:
383 case mm_mthc1_op:
384 if (insn.mm_fp1_format.op == mm_mfc1_op)
385 op = mfc_op;
386 else if (insn.mm_fp1_format.op == mm_mtc1_op)
387 op = mtc_op;
388 else if (insn.mm_fp1_format.op == mm_cfc1_op)
389 op = cfc_op;
390 else if (insn.mm_fp1_format.op == mm_ctc1_op)
391 op = ctc_op;
392 else if (insn.mm_fp1_format.op == mm_mfhc1_op)
393 op = mfhc_op;
394 else
395 op = mthc_op;
396 mips32_insn.fp1_format.opcode = cop1_op;
397 mips32_insn.fp1_format.op = op;
398 mips32_insn.fp1_format.rt =
399 insn.mm_fp1_format.rt;
400 mips32_insn.fp1_format.fs =
401 insn.mm_fp1_format.fs;
402 mips32_insn.fp1_format.fd = 0;
403 mips32_insn.fp1_format.func = 0;
404 break;
405 default:
406 return SIGILL;
407 }
408 break;
409 case mm_32f_74_op: /* c.cond.fmt */
410 mips32_insn.fp0_format.opcode = cop1_op;
411 mips32_insn.fp0_format.fmt =
412 sdps_format[insn.mm_fp4_format.fmt];
413 mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
414 mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
415 mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
416 mips32_insn.fp0_format.func =
417 insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
418 break;
419 default:
420 return SIGILL;
421 }
422 break;
423 default:
424 return SIGILL;
425 }
426
427 *insn_ptr = mips32_insn;
428 return 0;
429 }
430
431 /*
432 * Redundant with logic already in kernel/branch.c,
433 * embedded in compute_return_epc. At some point,
434 * a single subroutine should be used across both
435 * modules.
436 */
437 static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
438 unsigned long *contpc)
439 {
440 union mips_instruction insn = (union mips_instruction)dec_insn.insn;
441 unsigned int fcr31;
442 unsigned int bit = 0;
443
444 switch (insn.i_format.opcode) {
445 case spec_op:
446 switch (insn.r_format.func) {
447 case jalr_op:
448 regs->regs[insn.r_format.rd] =
449 regs->cp0_epc + dec_insn.pc_inc +
450 dec_insn.next_pc_inc;
451 /* Fall through */
452 case jr_op:
453 /* For R6, JR already emulated in jalr_op */
454 if (NO_R6EMU && insn.r_format.func == jr_op)
455 break;
456 *contpc = regs->regs[insn.r_format.rs];
457 return 1;
458 }
459 break;
460 case bcond_op:
461 switch (insn.i_format.rt) {
462 case bltzal_op:
463 case bltzall_op:
464 if (NO_R6EMU && (insn.i_format.rs ||
465 insn.i_format.rt == bltzall_op))
466 break;
467
468 regs->regs[31] = regs->cp0_epc +
469 dec_insn.pc_inc +
470 dec_insn.next_pc_inc;
471 /* Fall through */
472 case bltzl_op:
473 if (NO_R6EMU)
474 break;
475 case bltz_op:
476 if ((long)regs->regs[insn.i_format.rs] < 0)
477 *contpc = regs->cp0_epc +
478 dec_insn.pc_inc +
479 (insn.i_format.simmediate << 2);
480 else
481 *contpc = regs->cp0_epc +
482 dec_insn.pc_inc +
483 dec_insn.next_pc_inc;
484 return 1;
485 case bgezal_op:
486 case bgezall_op:
487 if (NO_R6EMU && (insn.i_format.rs ||
488 insn.i_format.rt == bgezall_op))
489 break;
490
491 regs->regs[31] = regs->cp0_epc +
492 dec_insn.pc_inc +
493 dec_insn.next_pc_inc;
494 /* Fall through */
495 case bgezl_op:
496 if (NO_R6EMU)
497 break;
498 case bgez_op:
499 if ((long)regs->regs[insn.i_format.rs] >= 0)
500 *contpc = regs->cp0_epc +
501 dec_insn.pc_inc +
502 (insn.i_format.simmediate << 2);
503 else
504 *contpc = regs->cp0_epc +
505 dec_insn.pc_inc +
506 dec_insn.next_pc_inc;
507 return 1;
508 }
509 break;
510 case jalx_op:
511 set_isa16_mode(bit);
512 case jal_op:
513 regs->regs[31] = regs->cp0_epc +
514 dec_insn.pc_inc +
515 dec_insn.next_pc_inc;
516 /* Fall through */
517 case j_op:
518 *contpc = regs->cp0_epc + dec_insn.pc_inc;
519 *contpc >>= 28;
520 *contpc <<= 28;
521 *contpc |= (insn.j_format.target << 2);
522 /* Set microMIPS mode bit: XOR for jalx. */
523 *contpc ^= bit;
524 return 1;
525 case beql_op:
526 if (NO_R6EMU)
527 break;
528 case beq_op:
529 if (regs->regs[insn.i_format.rs] ==
530 regs->regs[insn.i_format.rt])
531 *contpc = regs->cp0_epc +
532 dec_insn.pc_inc +
533 (insn.i_format.simmediate << 2);
534 else
535 *contpc = regs->cp0_epc +
536 dec_insn.pc_inc +
537 dec_insn.next_pc_inc;
538 return 1;
539 case bnel_op:
540 if (NO_R6EMU)
541 break;
542 case bne_op:
543 if (regs->regs[insn.i_format.rs] !=
544 regs->regs[insn.i_format.rt])
545 *contpc = regs->cp0_epc +
546 dec_insn.pc_inc +
547 (insn.i_format.simmediate << 2);
548 else
549 *contpc = regs->cp0_epc +
550 dec_insn.pc_inc +
551 dec_insn.next_pc_inc;
552 return 1;
553 case blezl_op:
554 if (!insn.i_format.rt && NO_R6EMU)
555 break;
556 case blez_op:
557
558 /*
559 * Compact branches for R6 for the
560 * blez and blezl opcodes.
561 * BLEZ | rs = 0 | rt != 0 == BLEZALC
562 * BLEZ | rs = rt != 0 == BGEZALC
563 * BLEZ | rs != 0 | rt != 0 == BGEUC
564 * BLEZL | rs = 0 | rt != 0 == BLEZC
565 * BLEZL | rs = rt != 0 == BGEZC
566 * BLEZL | rs != 0 | rt != 0 == BGEC
567 *
568 * For real BLEZ{,L}, rt is always 0.
569 */
570 if (cpu_has_mips_r6 && insn.i_format.rt) {
571 if ((insn.i_format.opcode == blez_op) &&
572 ((!insn.i_format.rs && insn.i_format.rt) ||
573 (insn.i_format.rs == insn.i_format.rt)))
574 regs->regs[31] = regs->cp0_epc +
575 dec_insn.pc_inc;
576 *contpc = regs->cp0_epc + dec_insn.pc_inc +
577 dec_insn.next_pc_inc;
578
579 return 1;
580 }
581 if ((long)regs->regs[insn.i_format.rs] <= 0)
582 *contpc = regs->cp0_epc +
583 dec_insn.pc_inc +
584 (insn.i_format.simmediate << 2);
585 else
586 *contpc = regs->cp0_epc +
587 dec_insn.pc_inc +
588 dec_insn.next_pc_inc;
589 return 1;
590 case bgtzl_op:
591 if (!insn.i_format.rt && NO_R6EMU)
592 break;
593 case bgtz_op:
594 /*
595 * Compact branches for R6 for the
596 * bgtz and bgtzl opcodes.
597 * BGTZ | rs = 0 | rt != 0 == BGTZALC
598 * BGTZ | rs = rt != 0 == BLTZALC
599 * BGTZ | rs != 0 | rt != 0 == BLTUC
600 * BGTZL | rs = 0 | rt != 0 == BGTZC
601 * BGTZL | rs = rt != 0 == BLTZC
602 * BGTZL | rs != 0 | rt != 0 == BLTC
603 *
604 * *ZALC varint for BGTZ &&& rt != 0
605 * For real GTZ{,L}, rt is always 0.
606 */
607 if (cpu_has_mips_r6 && insn.i_format.rt) {
608 if ((insn.i_format.opcode == blez_op) &&
609 ((!insn.i_format.rs && insn.i_format.rt) ||
610 (insn.i_format.rs == insn.i_format.rt)))
611 regs->regs[31] = regs->cp0_epc +
612 dec_insn.pc_inc;
613 *contpc = regs->cp0_epc + dec_insn.pc_inc +
614 dec_insn.next_pc_inc;
615
616 return 1;
617 }
618
619 if ((long)regs->regs[insn.i_format.rs] > 0)
620 *contpc = regs->cp0_epc +
621 dec_insn.pc_inc +
622 (insn.i_format.simmediate << 2);
623 else
624 *contpc = regs->cp0_epc +
625 dec_insn.pc_inc +
626 dec_insn.next_pc_inc;
627 return 1;
628 case cbcond0_op:
629 case cbcond1_op:
630 if (!cpu_has_mips_r6)
631 break;
632 if (insn.i_format.rt && !insn.i_format.rs)
633 regs->regs[31] = regs->cp0_epc + 4;
634 *contpc = regs->cp0_epc + dec_insn.pc_inc +
635 dec_insn.next_pc_inc;
636
637 return 1;
638 #ifdef CONFIG_CPU_CAVIUM_OCTEON
639 case lwc2_op: /* This is bbit0 on Octeon */
640 if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
641 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
642 else
643 *contpc = regs->cp0_epc + 8;
644 return 1;
645 case ldc2_op: /* This is bbit032 on Octeon */
646 if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
647 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
648 else
649 *contpc = regs->cp0_epc + 8;
650 return 1;
651 case swc2_op: /* This is bbit1 on Octeon */
652 if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
653 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
654 else
655 *contpc = regs->cp0_epc + 8;
656 return 1;
657 case sdc2_op: /* This is bbit132 on Octeon */
658 if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
659 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
660 else
661 *contpc = regs->cp0_epc + 8;
662 return 1;
663 #else
664 case bc6_op:
665 /*
666 * Only valid for MIPS R6 but we can still end up
667 * here from a broken userland so just tell emulator
668 * this is not a branch and let it break later on.
669 */
670 if (!cpu_has_mips_r6)
671 break;
672 *contpc = regs->cp0_epc + dec_insn.pc_inc +
673 dec_insn.next_pc_inc;
674
675 return 1;
676 case balc6_op:
677 if (!cpu_has_mips_r6)
678 break;
679 regs->regs[31] = regs->cp0_epc + 4;
680 *contpc = regs->cp0_epc + dec_insn.pc_inc +
681 dec_insn.next_pc_inc;
682
683 return 1;
684 case beqzcjic_op:
685 if (!cpu_has_mips_r6)
686 break;
687 *contpc = regs->cp0_epc + dec_insn.pc_inc +
688 dec_insn.next_pc_inc;
689
690 return 1;
691 case bnezcjialc_op:
692 if (!cpu_has_mips_r6)
693 break;
694 if (!insn.i_format.rs)
695 regs->regs[31] = regs->cp0_epc + 4;
696 *contpc = regs->cp0_epc + dec_insn.pc_inc +
697 dec_insn.next_pc_inc;
698
699 return 1;
700 #endif
701 case cop0_op:
702 case cop1_op:
703 /* Need to check for R6 bc1nez and bc1eqz branches */
704 if (cpu_has_mips_r6 &&
705 ((insn.i_format.rs == bc1eqz_op) ||
706 (insn.i_format.rs == bc1nez_op))) {
707 bit = 0;
708 switch (insn.i_format.rs) {
709 case bc1eqz_op:
710 if (get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1)
711 bit = 1;
712 break;
713 case bc1nez_op:
714 if (!(get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1))
715 bit = 1;
716 break;
717 }
718 if (bit)
719 *contpc = regs->cp0_epc +
720 dec_insn.pc_inc +
721 (insn.i_format.simmediate << 2);
722 else
723 *contpc = regs->cp0_epc +
724 dec_insn.pc_inc +
725 dec_insn.next_pc_inc;
726
727 return 1;
728 }
729 /* R2/R6 compatible cop1 instruction. Fall through */
730 case cop2_op:
731 case cop1x_op:
732 if (insn.i_format.rs == bc_op) {
733 preempt_disable();
734 if (is_fpu_owner())
735 fcr31 = read_32bit_cp1_register(CP1_STATUS);
736 else
737 fcr31 = current->thread.fpu.fcr31;
738 preempt_enable();
739
740 bit = (insn.i_format.rt >> 2);
741 bit += (bit != 0);
742 bit += 23;
743 switch (insn.i_format.rt & 3) {
744 case 0: /* bc1f */
745 case 2: /* bc1fl */
746 if (~fcr31 & (1 << bit))
747 *contpc = regs->cp0_epc +
748 dec_insn.pc_inc +
749 (insn.i_format.simmediate << 2);
750 else
751 *contpc = regs->cp0_epc +
752 dec_insn.pc_inc +
753 dec_insn.next_pc_inc;
754 return 1;
755 case 1: /* bc1t */
756 case 3: /* bc1tl */
757 if (fcr31 & (1 << bit))
758 *contpc = regs->cp0_epc +
759 dec_insn.pc_inc +
760 (insn.i_format.simmediate << 2);
761 else
762 *contpc = regs->cp0_epc +
763 dec_insn.pc_inc +
764 dec_insn.next_pc_inc;
765 return 1;
766 }
767 }
768 break;
769 }
770 return 0;
771 }
772
773 /*
774 * In the Linux kernel, we support selection of FPR format on the
775 * basis of the Status.FR bit. If an FPU is not present, the FR bit
776 * is hardwired to zero, which would imply a 32-bit FPU even for
777 * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
778 * FPU emu is slow and bulky and optimizing this function offers fairly
779 * sizeable benefits so we try to be clever and make this function return
780 * a constant whenever possible, that is on 64-bit kernels without O32
781 * compatibility enabled and on 32-bit without 64-bit FPU support.
782 */
783 static inline int cop1_64bit(struct pt_regs *xcp)
784 {
785 if (config_enabled(CONFIG_64BIT) && !config_enabled(CONFIG_MIPS32_O32))
786 return 1;
787 else if (config_enabled(CONFIG_32BIT) &&
788 !config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT))
789 return 0;
790
791 return !test_thread_flag(TIF_32BIT_FPREGS);
792 }
793
794 static inline bool hybrid_fprs(void)
795 {
796 return test_thread_flag(TIF_HYBRID_FPREGS);
797 }
798
799 #define SIFROMREG(si, x) \
800 do { \
801 if (cop1_64bit(xcp) && !hybrid_fprs()) \
802 (si) = (int)get_fpr32(&ctx->fpr[x], 0); \
803 else \
804 (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \
805 } while (0)
806
807 #define SITOREG(si, x) \
808 do { \
809 if (cop1_64bit(xcp) && !hybrid_fprs()) { \
810 unsigned i; \
811 set_fpr32(&ctx->fpr[x], 0, si); \
812 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
813 set_fpr32(&ctx->fpr[x], i, 0); \
814 } else { \
815 set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si); \
816 } \
817 } while (0)
818
819 #define SIFROMHREG(si, x) ((si) = (int)get_fpr32(&ctx->fpr[x], 1))
820
821 #define SITOHREG(si, x) \
822 do { \
823 unsigned i; \
824 set_fpr32(&ctx->fpr[x], 1, si); \
825 for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
826 set_fpr32(&ctx->fpr[x], i, 0); \
827 } while (0)
828
829 #define DIFROMREG(di, x) \
830 ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0))
831
832 #define DITOREG(di, x) \
833 do { \
834 unsigned fpr, i; \
835 fpr = (x) & ~(cop1_64bit(xcp) == 0); \
836 set_fpr64(&ctx->fpr[fpr], 0, di); \
837 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++) \
838 set_fpr64(&ctx->fpr[fpr], i, 0); \
839 } while (0)
840
841 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
842 #define SPTOREG(sp, x) SITOREG((sp).bits, x)
843 #define DPFROMREG(dp, x) DIFROMREG((dp).bits, x)
844 #define DPTOREG(dp, x) DITOREG((dp).bits, x)
845
846 /*
847 * Emulate a CFC1 instruction.
848 */
849 static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
850 mips_instruction ir)
851 {
852 u32 fcr31 = ctx->fcr31;
853 u32 value = 0;
854
855 switch (MIPSInst_RD(ir)) {
856 case FPCREG_CSR:
857 value = fcr31;
858 pr_debug("%p gpr[%d]<-csr=%08x\n",
859 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
860 break;
861
862 case FPCREG_FENR:
863 if (!cpu_has_mips_r)
864 break;
865 value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
866 MIPS_FENR_FS;
867 value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM);
868 pr_debug("%p gpr[%d]<-enr=%08x\n",
869 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
870 break;
871
872 case FPCREG_FEXR:
873 if (!cpu_has_mips_r)
874 break;
875 value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
876 pr_debug("%p gpr[%d]<-exr=%08x\n",
877 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
878 break;
879
880 case FPCREG_FCCR:
881 if (!cpu_has_mips_r)
882 break;
883 value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
884 MIPS_FCCR_COND0;
885 value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
886 (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0);
887 pr_debug("%p gpr[%d]<-ccr=%08x\n",
888 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
889 break;
890
891 case FPCREG_RID:
892 value = boot_cpu_data.fpu_id;
893 break;
894
895 default:
896 break;
897 }
898
899 if (MIPSInst_RT(ir))
900 xcp->regs[MIPSInst_RT(ir)] = value;
901 }
902
903 /*
904 * Emulate a CTC1 instruction.
905 */
906 static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
907 mips_instruction ir)
908 {
909 u32 fcr31 = ctx->fcr31;
910 u32 value;
911 u32 mask;
912
913 if (MIPSInst_RT(ir) == 0)
914 value = 0;
915 else
916 value = xcp->regs[MIPSInst_RT(ir)];
917
918 switch (MIPSInst_RD(ir)) {
919 case FPCREG_CSR:
920 pr_debug("%p gpr[%d]->csr=%08x\n",
921 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
922
923 /* Preserve read-only bits. */
924 mask = boot_cpu_data.fpu_msk31;
925 fcr31 = (value & ~mask) | (fcr31 & mask);
926 break;
927
928 case FPCREG_FENR:
929 if (!cpu_has_mips_r)
930 break;
931 pr_debug("%p gpr[%d]->enr=%08x\n",
932 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
933 fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM);
934 fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
935 FPU_CSR_FS;
936 fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM);
937 break;
938
939 case FPCREG_FEXR:
940 if (!cpu_has_mips_r)
941 break;
942 pr_debug("%p gpr[%d]->exr=%08x\n",
943 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
944 fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S);
945 fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
946 break;
947
948 case FPCREG_FCCR:
949 if (!cpu_has_mips_r)
950 break;
951 pr_debug("%p gpr[%d]->ccr=%08x\n",
952 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
953 fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND);
954 fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
955 FPU_CSR_COND;
956 fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
957 FPU_CSR_CONDX;
958 break;
959
960 default:
961 break;
962 }
963
964 ctx->fcr31 = fcr31;
965 }
966
967 /*
968 * Emulate the single floating point instruction pointed at by EPC.
969 * Two instructions if the instruction is in a branch delay slot.
970 */
971
972 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
973 struct mm_decoded_insn dec_insn, void *__user *fault_addr)
974 {
975 unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
976 unsigned int cond, cbit;
977 mips_instruction ir;
978 int likely, pc_inc;
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 it
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
1045 emul:
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(VERIFY_READ, 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(VERIFY_WRITE, 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(VERIFY_READ, 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(VERIFY_WRITE, 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 goto 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 goto 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 cond = likely = 0;
1190 switch (MIPSInst_RS(ir)) {
1191 case bc1eqz_op:
1192 if (get_fpr32(&current->thread.fpu.fpr[MIPSInst_RT(ir)], 0) & 0x1)
1193 cond = 1;
1194 break;
1195 case bc1nez_op:
1196 if (!(get_fpr32(&current->thread.fpu.fpr[MIPSInst_RT(ir)], 0) & 0x1))
1197 cond = 1;
1198 break;
1199 }
1200 goto branch_common;
1201
1202 case bc_op:
1203 if (delay_slot(xcp))
1204 return SIGILL;
1205
1206 if (cpu_has_mips_4_5_r)
1207 cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
1208 else
1209 cbit = FPU_CSR_COND;
1210 cond = ctx->fcr31 & cbit;
1211
1212 likely = 0;
1213 switch (MIPSInst_RT(ir) & 3) {
1214 case bcfl_op:
1215 if (cpu_has_mips_2_3_4_5_r)
1216 likely = 1;
1217 /* Fall through */
1218 case bcf_op:
1219 cond = !cond;
1220 break;
1221 case bctl_op:
1222 if (cpu_has_mips_2_3_4_5_r)
1223 likely = 1;
1224 /* Fall through */
1225 case bct_op:
1226 break;
1227 }
1228 branch_common:
1229 set_delay_slot(xcp);
1230 if (cond) {
1231 /*
1232 * Branch taken: emulate dslot instruction
1233 */
1234 unsigned long bcpc;
1235
1236 /*
1237 * Remember EPC at the branch to point back
1238 * at so that any delay-slot instruction
1239 * signal is not silently ignored.
1240 */
1241 bcpc = xcp->cp0_epc;
1242 xcp->cp0_epc += dec_insn.pc_inc;
1243
1244 contpc = MIPSInst_SIMM(ir);
1245 ir = dec_insn.next_insn;
1246 if (dec_insn.micro_mips_mode) {
1247 contpc = (xcp->cp0_epc + (contpc << 1));
1248
1249 /* If 16-bit instruction, not FPU. */
1250 if ((dec_insn.next_pc_inc == 2) ||
1251 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
1252
1253 /*
1254 * Since this instruction will
1255 * be put on the stack with
1256 * 32-bit words, get around
1257 * this problem by putting a
1258 * NOP16 as the second one.
1259 */
1260 if (dec_insn.next_pc_inc == 2)
1261 ir = (ir & (~0xffff)) | MM_NOP16;
1262
1263 /*
1264 * Single step the non-CP1
1265 * instruction in the dslot.
1266 */
1267 sig = mips_dsemul(xcp, ir,
1268 contpc);
1269 if (sig)
1270 xcp->cp0_epc = bcpc;
1271 /*
1272 * SIGILL forces out of
1273 * the emulation loop.
1274 */
1275 return sig ? sig : SIGILL;
1276 }
1277 } else
1278 contpc = (xcp->cp0_epc + (contpc << 2));
1279
1280 switch (MIPSInst_OPCODE(ir)) {
1281 case lwc1_op:
1282 case swc1_op:
1283 goto emul;
1284
1285 case ldc1_op:
1286 case sdc1_op:
1287 if (cpu_has_mips_2_3_4_5_r)
1288 goto emul;
1289
1290 goto bc_sigill;
1291
1292 case cop1_op:
1293 goto emul;
1294
1295 case cop1x_op:
1296 if (cpu_has_mips_4_5_64_r2_r6)
1297 /* its one of ours */
1298 goto emul;
1299
1300 goto bc_sigill;
1301
1302 case spec_op:
1303 switch (MIPSInst_FUNC(ir)) {
1304 case movc_op:
1305 if (cpu_has_mips_4_5_r)
1306 goto emul;
1307
1308 goto bc_sigill;
1309 }
1310 break;
1311
1312 bc_sigill:
1313 xcp->cp0_epc = bcpc;
1314 return SIGILL;
1315 }
1316
1317 /*
1318 * Single step the non-cp1
1319 * instruction in the dslot
1320 */
1321 sig = mips_dsemul(xcp, ir, contpc);
1322 if (sig)
1323 xcp->cp0_epc = bcpc;
1324 /* SIGILL forces out of the emulation loop. */
1325 return sig ? sig : SIGILL;
1326 } else if (likely) { /* branch not taken */
1327 /*
1328 * branch likely nullifies
1329 * dslot if not taken
1330 */
1331 xcp->cp0_epc += dec_insn.pc_inc;
1332 contpc += dec_insn.pc_inc;
1333 /*
1334 * else continue & execute
1335 * dslot as normal insn
1336 */
1337 }
1338 break;
1339
1340 default:
1341 if (!(MIPSInst_RS(ir) & 0x10))
1342 return SIGILL;
1343
1344 /* a real fpu computation instruction */
1345 if ((sig = fpu_emu(xcp, ctx, ir)))
1346 return sig;
1347 }
1348 break;
1349
1350 case cop1x_op:
1351 if (!cpu_has_mips_4_5_64_r2_r6)
1352 return SIGILL;
1353
1354 sig = fpux_emu(xcp, ctx, ir, fault_addr);
1355 if (sig)
1356 return sig;
1357 break;
1358
1359 case spec_op:
1360 if (!cpu_has_mips_4_5_r)
1361 return SIGILL;
1362
1363 if (MIPSInst_FUNC(ir) != movc_op)
1364 return SIGILL;
1365 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
1366 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
1367 xcp->regs[MIPSInst_RD(ir)] =
1368 xcp->regs[MIPSInst_RS(ir)];
1369 break;
1370 default:
1371 sigill:
1372 return SIGILL;
1373 }
1374
1375 /* we did it !! */
1376 xcp->cp0_epc = contpc;
1377 clear_delay_slot(xcp);
1378
1379 return 0;
1380 }
1381
1382 /*
1383 * Conversion table from MIPS compare ops 48-63
1384 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
1385 */
1386 static const unsigned char cmptab[8] = {
1387 0, /* cmp_0 (sig) cmp_sf */
1388 IEEE754_CUN, /* cmp_un (sig) cmp_ngle */
1389 IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */
1390 IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */
1391 IEEE754_CLT, /* cmp_olt (sig) cmp_lt */
1392 IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */
1393 IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */
1394 IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */
1395 };
1396
1397 static const unsigned char negative_cmptab[8] = {
1398 0, /* Reserved */
1399 IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ,
1400 IEEE754_CLT | IEEE754_CGT | IEEE754_CUN,
1401 IEEE754_CLT | IEEE754_CGT,
1402 /* Reserved */
1403 };
1404
1405
1406 /*
1407 * Additional MIPS4 instructions
1408 */
1409
1410 #define DEF3OP(name, p, f1, f2, f3) \
1411 static union ieee754##p fpemu_##p##_##name(union ieee754##p r, \
1412 union ieee754##p s, union ieee754##p t) \
1413 { \
1414 struct _ieee754_csr ieee754_csr_save; \
1415 s = f1(s, t); \
1416 ieee754_csr_save = ieee754_csr; \
1417 s = f2(s, r); \
1418 ieee754_csr_save.cx |= ieee754_csr.cx; \
1419 ieee754_csr_save.sx |= ieee754_csr.sx; \
1420 s = f3(s); \
1421 ieee754_csr.cx |= ieee754_csr_save.cx; \
1422 ieee754_csr.sx |= ieee754_csr_save.sx; \
1423 return s; \
1424 }
1425
1426 static union ieee754dp fpemu_dp_recip(union ieee754dp d)
1427 {
1428 return ieee754dp_div(ieee754dp_one(0), d);
1429 }
1430
1431 static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
1432 {
1433 return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
1434 }
1435
1436 static union ieee754sp fpemu_sp_recip(union ieee754sp s)
1437 {
1438 return ieee754sp_div(ieee754sp_one(0), s);
1439 }
1440
1441 static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s)
1442 {
1443 return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
1444 }
1445
1446 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
1447 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
1448 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
1449 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
1450 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
1451 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
1452 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
1453 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
1454
1455 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1456 mips_instruction ir, void *__user *fault_addr)
1457 {
1458 unsigned rcsr = 0; /* resulting csr */
1459
1460 MIPS_FPU_EMU_INC_STATS(cp1xops);
1461
1462 switch (MIPSInst_FMA_FFMT(ir)) {
1463 case s_fmt:{ /* 0 */
1464
1465 union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
1466 union ieee754sp fd, fr, fs, ft;
1467 u32 __user *va;
1468 u32 val;
1469
1470 switch (MIPSInst_FUNC(ir)) {
1471 case lwxc1_op:
1472 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1473 xcp->regs[MIPSInst_FT(ir)]);
1474
1475 MIPS_FPU_EMU_INC_STATS(loads);
1476 if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
1477 MIPS_FPU_EMU_INC_STATS(errors);
1478 *fault_addr = va;
1479 return SIGBUS;
1480 }
1481 if (__get_user(val, va)) {
1482 MIPS_FPU_EMU_INC_STATS(errors);
1483 *fault_addr = va;
1484 return SIGSEGV;
1485 }
1486 SITOREG(val, MIPSInst_FD(ir));
1487 break;
1488
1489 case swxc1_op:
1490 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1491 xcp->regs[MIPSInst_FT(ir)]);
1492
1493 MIPS_FPU_EMU_INC_STATS(stores);
1494
1495 SIFROMREG(val, MIPSInst_FS(ir));
1496 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
1497 MIPS_FPU_EMU_INC_STATS(errors);
1498 *fault_addr = va;
1499 return SIGBUS;
1500 }
1501 if (put_user(val, va)) {
1502 MIPS_FPU_EMU_INC_STATS(errors);
1503 *fault_addr = va;
1504 return SIGSEGV;
1505 }
1506 break;
1507
1508 case madd_s_op:
1509 handler = fpemu_sp_madd;
1510 goto scoptop;
1511 case msub_s_op:
1512 handler = fpemu_sp_msub;
1513 goto scoptop;
1514 case nmadd_s_op:
1515 handler = fpemu_sp_nmadd;
1516 goto scoptop;
1517 case nmsub_s_op:
1518 handler = fpemu_sp_nmsub;
1519 goto scoptop;
1520
1521 scoptop:
1522 SPFROMREG(fr, MIPSInst_FR(ir));
1523 SPFROMREG(fs, MIPSInst_FS(ir));
1524 SPFROMREG(ft, MIPSInst_FT(ir));
1525 fd = (*handler) (fr, fs, ft);
1526 SPTOREG(fd, MIPSInst_FD(ir));
1527
1528 copcsr:
1529 if (ieee754_cxtest(IEEE754_INEXACT)) {
1530 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1531 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1532 }
1533 if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1534 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1535 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1536 }
1537 if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1538 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1539 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1540 }
1541 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1542 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1543 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1544 }
1545
1546 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1547 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1548 /*printk ("SIGFPE: FPU csr = %08x\n",
1549 ctx->fcr31); */
1550 return SIGFPE;
1551 }
1552
1553 break;
1554
1555 default:
1556 return SIGILL;
1557 }
1558 break;
1559 }
1560
1561 case d_fmt:{ /* 1 */
1562 union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
1563 union ieee754dp fd, fr, fs, ft;
1564 u64 __user *va;
1565 u64 val;
1566
1567 switch (MIPSInst_FUNC(ir)) {
1568 case ldxc1_op:
1569 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1570 xcp->regs[MIPSInst_FT(ir)]);
1571
1572 MIPS_FPU_EMU_INC_STATS(loads);
1573 if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
1574 MIPS_FPU_EMU_INC_STATS(errors);
1575 *fault_addr = va;
1576 return SIGBUS;
1577 }
1578 if (__get_user(val, va)) {
1579 MIPS_FPU_EMU_INC_STATS(errors);
1580 *fault_addr = va;
1581 return SIGSEGV;
1582 }
1583 DITOREG(val, MIPSInst_FD(ir));
1584 break;
1585
1586 case sdxc1_op:
1587 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1588 xcp->regs[MIPSInst_FT(ir)]);
1589
1590 MIPS_FPU_EMU_INC_STATS(stores);
1591 DIFROMREG(val, MIPSInst_FS(ir));
1592 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
1593 MIPS_FPU_EMU_INC_STATS(errors);
1594 *fault_addr = va;
1595 return SIGBUS;
1596 }
1597 if (__put_user(val, va)) {
1598 MIPS_FPU_EMU_INC_STATS(errors);
1599 *fault_addr = va;
1600 return SIGSEGV;
1601 }
1602 break;
1603
1604 case madd_d_op:
1605 handler = fpemu_dp_madd;
1606 goto dcoptop;
1607 case msub_d_op:
1608 handler = fpemu_dp_msub;
1609 goto dcoptop;
1610 case nmadd_d_op:
1611 handler = fpemu_dp_nmadd;
1612 goto dcoptop;
1613 case nmsub_d_op:
1614 handler = fpemu_dp_nmsub;
1615 goto dcoptop;
1616
1617 dcoptop:
1618 DPFROMREG(fr, MIPSInst_FR(ir));
1619 DPFROMREG(fs, MIPSInst_FS(ir));
1620 DPFROMREG(ft, MIPSInst_FT(ir));
1621 fd = (*handler) (fr, fs, ft);
1622 DPTOREG(fd, MIPSInst_FD(ir));
1623 goto copcsr;
1624
1625 default:
1626 return SIGILL;
1627 }
1628 break;
1629 }
1630
1631 case 0x3:
1632 if (MIPSInst_FUNC(ir) != pfetch_op)
1633 return SIGILL;
1634
1635 /* ignore prefx operation */
1636 break;
1637
1638 default:
1639 return SIGILL;
1640 }
1641
1642 return 0;
1643 }
1644
1645
1646
1647 /*
1648 * Emulate a single COP1 arithmetic instruction.
1649 */
1650 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1651 mips_instruction ir)
1652 {
1653 int rfmt; /* resulting format */
1654 unsigned rcsr = 0; /* resulting csr */
1655 unsigned int oldrm;
1656 unsigned int cbit;
1657 unsigned cond;
1658 union {
1659 union ieee754dp d;
1660 union ieee754sp s;
1661 int w;
1662 s64 l;
1663 } rv; /* resulting value */
1664 u64 bits;
1665
1666 MIPS_FPU_EMU_INC_STATS(cp1ops);
1667 switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
1668 case s_fmt: { /* 0 */
1669 union {
1670 union ieee754sp(*b) (union ieee754sp, union ieee754sp);
1671 union ieee754sp(*u) (union ieee754sp);
1672 } handler;
1673 union ieee754sp fs, ft;
1674
1675 switch (MIPSInst_FUNC(ir)) {
1676 /* binary ops */
1677 case fadd_op:
1678 handler.b = ieee754sp_add;
1679 goto scopbop;
1680 case fsub_op:
1681 handler.b = ieee754sp_sub;
1682 goto scopbop;
1683 case fmul_op:
1684 handler.b = ieee754sp_mul;
1685 goto scopbop;
1686 case fdiv_op:
1687 handler.b = ieee754sp_div;
1688 goto scopbop;
1689
1690 /* unary ops */
1691 case fsqrt_op:
1692 if (!cpu_has_mips_2_3_4_5_r)
1693 return SIGILL;
1694
1695 handler.u = ieee754sp_sqrt;
1696 goto scopuop;
1697
1698 /*
1699 * Note that on some MIPS IV implementations such as the
1700 * R5000 and R8000 the FSQRT and FRECIP instructions do not
1701 * achieve full IEEE-754 accuracy - however this emulator does.
1702 */
1703 case frsqrt_op:
1704 if (!cpu_has_mips_4_5_64_r2_r6)
1705 return SIGILL;
1706
1707 handler.u = fpemu_sp_rsqrt;
1708 goto scopuop;
1709
1710 case frecip_op:
1711 if (!cpu_has_mips_4_5_64_r2_r6)
1712 return SIGILL;
1713
1714 handler.u = fpemu_sp_recip;
1715 goto scopuop;
1716
1717 case fmovc_op:
1718 if (!cpu_has_mips_4_5_r)
1719 return SIGILL;
1720
1721 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1722 if (((ctx->fcr31 & cond) != 0) !=
1723 ((MIPSInst_FT(ir) & 1) != 0))
1724 return 0;
1725 SPFROMREG(rv.s, MIPSInst_FS(ir));
1726 break;
1727
1728 case fmovz_op:
1729 if (!cpu_has_mips_4_5_r)
1730 return SIGILL;
1731
1732 if (xcp->regs[MIPSInst_FT(ir)] != 0)
1733 return 0;
1734 SPFROMREG(rv.s, MIPSInst_FS(ir));
1735 break;
1736
1737 case fmovn_op:
1738 if (!cpu_has_mips_4_5_r)
1739 return SIGILL;
1740
1741 if (xcp->regs[MIPSInst_FT(ir)] == 0)
1742 return 0;
1743 SPFROMREG(rv.s, MIPSInst_FS(ir));
1744 break;
1745
1746 case fseleqz_op:
1747 if (!cpu_has_mips_r6)
1748 return SIGILL;
1749
1750 SPFROMREG(rv.s, MIPSInst_FT(ir));
1751 if (rv.w & 0x1)
1752 rv.w = 0;
1753 else
1754 SPFROMREG(rv.s, MIPSInst_FS(ir));
1755 break;
1756
1757 case fselnez_op:
1758 if (!cpu_has_mips_r6)
1759 return SIGILL;
1760
1761 SPFROMREG(rv.s, MIPSInst_FT(ir));
1762 if (rv.w & 0x1)
1763 SPFROMREG(rv.s, MIPSInst_FS(ir));
1764 else
1765 rv.w = 0;
1766 break;
1767
1768 case fabs_op:
1769 handler.u = ieee754sp_abs;
1770 goto scopuop;
1771
1772 case fneg_op:
1773 handler.u = ieee754sp_neg;
1774 goto scopuop;
1775
1776 case fmov_op:
1777 /* an easy one */
1778 SPFROMREG(rv.s, MIPSInst_FS(ir));
1779 goto copcsr;
1780
1781 /* binary op on handler */
1782 scopbop:
1783 SPFROMREG(fs, MIPSInst_FS(ir));
1784 SPFROMREG(ft, MIPSInst_FT(ir));
1785
1786 rv.s = (*handler.b) (fs, ft);
1787 goto copcsr;
1788 scopuop:
1789 SPFROMREG(fs, MIPSInst_FS(ir));
1790 rv.s = (*handler.u) (fs);
1791 goto copcsr;
1792 copcsr:
1793 if (ieee754_cxtest(IEEE754_INEXACT)) {
1794 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1795 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1796 }
1797 if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1798 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1799 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1800 }
1801 if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1802 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1803 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1804 }
1805 if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) {
1806 MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv);
1807 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
1808 }
1809 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1810 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1811 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1812 }
1813 break;
1814
1815 /* unary conv ops */
1816 case fcvts_op:
1817 return SIGILL; /* not defined */
1818
1819 case fcvtd_op:
1820 SPFROMREG(fs, MIPSInst_FS(ir));
1821 rv.d = ieee754dp_fsp(fs);
1822 rfmt = d_fmt;
1823 goto copcsr;
1824
1825 case fcvtw_op:
1826 SPFROMREG(fs, MIPSInst_FS(ir));
1827 rv.w = ieee754sp_tint(fs);
1828 rfmt = w_fmt;
1829 goto copcsr;
1830
1831 case fround_op:
1832 case ftrunc_op:
1833 case fceil_op:
1834 case ffloor_op:
1835 if (!cpu_has_mips_2_3_4_5_r)
1836 return SIGILL;
1837
1838 oldrm = ieee754_csr.rm;
1839 SPFROMREG(fs, MIPSInst_FS(ir));
1840 ieee754_csr.rm = MIPSInst_FUNC(ir);
1841 rv.w = ieee754sp_tint(fs);
1842 ieee754_csr.rm = oldrm;
1843 rfmt = w_fmt;
1844 goto copcsr;
1845
1846 case fcvtl_op:
1847 if (!cpu_has_mips_3_4_5_64_r2_r6)
1848 return SIGILL;
1849
1850 SPFROMREG(fs, MIPSInst_FS(ir));
1851 rv.l = ieee754sp_tlong(fs);
1852 rfmt = l_fmt;
1853 goto copcsr;
1854
1855 case froundl_op:
1856 case ftruncl_op:
1857 case fceill_op:
1858 case ffloorl_op:
1859 if (!cpu_has_mips_3_4_5_64_r2_r6)
1860 return SIGILL;
1861
1862 oldrm = ieee754_csr.rm;
1863 SPFROMREG(fs, MIPSInst_FS(ir));
1864 ieee754_csr.rm = MIPSInst_FUNC(ir);
1865 rv.l = ieee754sp_tlong(fs);
1866 ieee754_csr.rm = oldrm;
1867 rfmt = l_fmt;
1868 goto copcsr;
1869
1870 default:
1871 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
1872 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1873 union ieee754sp fs, ft;
1874
1875 SPFROMREG(fs, MIPSInst_FS(ir));
1876 SPFROMREG(ft, MIPSInst_FT(ir));
1877 rv.w = ieee754sp_cmp(fs, ft,
1878 cmptab[cmpop & 0x7], cmpop & 0x8);
1879 rfmt = -1;
1880 if ((cmpop & 0x8) && ieee754_cxtest
1881 (IEEE754_INVALID_OPERATION))
1882 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1883 else
1884 goto copcsr;
1885
1886 } else
1887 return SIGILL;
1888 break;
1889 }
1890 break;
1891 }
1892
1893 case d_fmt: {
1894 union ieee754dp fs, ft;
1895 union {
1896 union ieee754dp(*b) (union ieee754dp, union ieee754dp);
1897 union ieee754dp(*u) (union ieee754dp);
1898 } handler;
1899
1900 switch (MIPSInst_FUNC(ir)) {
1901 /* binary ops */
1902 case fadd_op:
1903 handler.b = ieee754dp_add;
1904 goto dcopbop;
1905 case fsub_op:
1906 handler.b = ieee754dp_sub;
1907 goto dcopbop;
1908 case fmul_op:
1909 handler.b = ieee754dp_mul;
1910 goto dcopbop;
1911 case fdiv_op:
1912 handler.b = ieee754dp_div;
1913 goto dcopbop;
1914
1915 /* unary ops */
1916 case fsqrt_op:
1917 if (!cpu_has_mips_2_3_4_5_r)
1918 return SIGILL;
1919
1920 handler.u = ieee754dp_sqrt;
1921 goto dcopuop;
1922 /*
1923 * Note that on some MIPS IV implementations such as the
1924 * R5000 and R8000 the FSQRT and FRECIP instructions do not
1925 * achieve full IEEE-754 accuracy - however this emulator does.
1926 */
1927 case frsqrt_op:
1928 if (!cpu_has_mips_4_5_64_r2_r6)
1929 return SIGILL;
1930
1931 handler.u = fpemu_dp_rsqrt;
1932 goto dcopuop;
1933 case frecip_op:
1934 if (!cpu_has_mips_4_5_64_r2_r6)
1935 return SIGILL;
1936
1937 handler.u = fpemu_dp_recip;
1938 goto dcopuop;
1939 case fmovc_op:
1940 if (!cpu_has_mips_4_5_r)
1941 return SIGILL;
1942
1943 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1944 if (((ctx->fcr31 & cond) != 0) !=
1945 ((MIPSInst_FT(ir) & 1) != 0))
1946 return 0;
1947 DPFROMREG(rv.d, MIPSInst_FS(ir));
1948 break;
1949 case fmovz_op:
1950 if (!cpu_has_mips_4_5_r)
1951 return SIGILL;
1952
1953 if (xcp->regs[MIPSInst_FT(ir)] != 0)
1954 return 0;
1955 DPFROMREG(rv.d, MIPSInst_FS(ir));
1956 break;
1957 case fmovn_op:
1958 if (!cpu_has_mips_4_5_r)
1959 return SIGILL;
1960
1961 if (xcp->regs[MIPSInst_FT(ir)] == 0)
1962 return 0;
1963 DPFROMREG(rv.d, MIPSInst_FS(ir));
1964 break;
1965
1966 case fseleqz_op:
1967 if (!cpu_has_mips_r6)
1968 return SIGILL;
1969
1970 DPFROMREG(rv.d, MIPSInst_FT(ir));
1971 if (rv.l & 0x1)
1972 rv.l = 0;
1973 else
1974 DPFROMREG(rv.d, MIPSInst_FS(ir));
1975 break;
1976
1977 case fselnez_op:
1978 if (!cpu_has_mips_r6)
1979 return SIGILL;
1980
1981 DPFROMREG(rv.d, MIPSInst_FT(ir));
1982 if (rv.l & 0x1)
1983 DPFROMREG(rv.d, MIPSInst_FS(ir));
1984 else
1985 rv.l = 0;
1986 break;
1987
1988 case fabs_op:
1989 handler.u = ieee754dp_abs;
1990 goto dcopuop;
1991
1992 case fneg_op:
1993 handler.u = ieee754dp_neg;
1994 goto dcopuop;
1995
1996 case fmov_op:
1997 /* an easy one */
1998 DPFROMREG(rv.d, MIPSInst_FS(ir));
1999 goto copcsr;
2000
2001 /* binary op on handler */
2002 dcopbop:
2003 DPFROMREG(fs, MIPSInst_FS(ir));
2004 DPFROMREG(ft, MIPSInst_FT(ir));
2005
2006 rv.d = (*handler.b) (fs, ft);
2007 goto copcsr;
2008 dcopuop:
2009 DPFROMREG(fs, MIPSInst_FS(ir));
2010 rv.d = (*handler.u) (fs);
2011 goto copcsr;
2012
2013 /*
2014 * unary conv ops
2015 */
2016 case fcvts_op:
2017 DPFROMREG(fs, MIPSInst_FS(ir));
2018 rv.s = ieee754sp_fdp(fs);
2019 rfmt = s_fmt;
2020 goto copcsr;
2021
2022 case fcvtd_op:
2023 return SIGILL; /* not defined */
2024
2025 case fcvtw_op:
2026 DPFROMREG(fs, MIPSInst_FS(ir));
2027 rv.w = ieee754dp_tint(fs); /* wrong */
2028 rfmt = w_fmt;
2029 goto copcsr;
2030
2031 case fround_op:
2032 case ftrunc_op:
2033 case fceil_op:
2034 case ffloor_op:
2035 if (!cpu_has_mips_2_3_4_5_r)
2036 return SIGILL;
2037
2038 oldrm = ieee754_csr.rm;
2039 DPFROMREG(fs, MIPSInst_FS(ir));
2040 ieee754_csr.rm = MIPSInst_FUNC(ir);
2041 rv.w = ieee754dp_tint(fs);
2042 ieee754_csr.rm = oldrm;
2043 rfmt = w_fmt;
2044 goto copcsr;
2045
2046 case fcvtl_op:
2047 if (!cpu_has_mips_3_4_5_64_r2_r6)
2048 return SIGILL;
2049
2050 DPFROMREG(fs, MIPSInst_FS(ir));
2051 rv.l = ieee754dp_tlong(fs);
2052 rfmt = l_fmt;
2053 goto copcsr;
2054
2055 case froundl_op:
2056 case ftruncl_op:
2057 case fceill_op:
2058 case ffloorl_op:
2059 if (!cpu_has_mips_3_4_5_64_r2_r6)
2060 return SIGILL;
2061
2062 oldrm = ieee754_csr.rm;
2063 DPFROMREG(fs, MIPSInst_FS(ir));
2064 ieee754_csr.rm = MIPSInst_FUNC(ir);
2065 rv.l = ieee754dp_tlong(fs);
2066 ieee754_csr.rm = oldrm;
2067 rfmt = l_fmt;
2068 goto copcsr;
2069
2070 default:
2071 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2072 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2073 union ieee754dp fs, ft;
2074
2075 DPFROMREG(fs, MIPSInst_FS(ir));
2076 DPFROMREG(ft, MIPSInst_FT(ir));
2077 rv.w = ieee754dp_cmp(fs, ft,
2078 cmptab[cmpop & 0x7], cmpop & 0x8);
2079 rfmt = -1;
2080 if ((cmpop & 0x8)
2081 &&
2082 ieee754_cxtest
2083 (IEEE754_INVALID_OPERATION))
2084 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2085 else
2086 goto copcsr;
2087
2088 }
2089 else {
2090 return SIGILL;
2091 }
2092 break;
2093 }
2094 break;
2095 }
2096
2097 case w_fmt: {
2098 union ieee754dp fs;
2099
2100 switch (MIPSInst_FUNC(ir)) {
2101 case fcvts_op:
2102 /* convert word to single precision real */
2103 SPFROMREG(fs, MIPSInst_FS(ir));
2104 rv.s = ieee754sp_fint(fs.bits);
2105 rfmt = s_fmt;
2106 goto copcsr;
2107 case fcvtd_op:
2108 /* convert word to double precision real */
2109 SPFROMREG(fs, MIPSInst_FS(ir));
2110 rv.d = ieee754dp_fint(fs.bits);
2111 rfmt = d_fmt;
2112 goto copcsr;
2113 default: {
2114 /* Emulating the new CMP.condn.fmt R6 instruction */
2115 #define CMPOP_MASK 0x7
2116 #define SIGN_BIT (0x1 << 3)
2117 #define PREDICATE_BIT (0x1 << 4)
2118
2119 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2120 int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2121 union ieee754sp fs, ft;
2122
2123 /* This is an R6 only instruction */
2124 if (!cpu_has_mips_r6 ||
2125 (MIPSInst_FUNC(ir) & 0x20))
2126 return SIGILL;
2127
2128 /* fmt is w_fmt for single precision so fix it */
2129 rfmt = s_fmt;
2130 /* default to false */
2131 rv.w = 0;
2132
2133 /* CMP.condn.S */
2134 SPFROMREG(fs, MIPSInst_FS(ir));
2135 SPFROMREG(ft, MIPSInst_FT(ir));
2136
2137 /* positive predicates */
2138 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2139 if (ieee754sp_cmp(fs, ft, cmptab[cmpop],
2140 sig))
2141 rv.w = -1; /* true, all 1s */
2142 if ((sig) &&
2143 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2144 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2145 else
2146 goto copcsr;
2147 } else {
2148 /* negative predicates */
2149 switch (cmpop) {
2150 case 1:
2151 case 2:
2152 case 3:
2153 if (ieee754sp_cmp(fs, ft,
2154 negative_cmptab[cmpop],
2155 sig))
2156 rv.w = -1; /* true, all 1s */
2157 if (sig &&
2158 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2159 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2160 else
2161 goto copcsr;
2162 break;
2163 default:
2164 /* Reserved R6 ops */
2165 pr_err("Reserved MIPS R6 CMP.condn.S operation\n");
2166 return SIGILL;
2167 }
2168 }
2169 break;
2170 }
2171 }
2172 }
2173
2174 case l_fmt:
2175
2176 if (!cpu_has_mips_3_4_5_64_r2_r6)
2177 return SIGILL;
2178
2179 DIFROMREG(bits, MIPSInst_FS(ir));
2180
2181 switch (MIPSInst_FUNC(ir)) {
2182 case fcvts_op:
2183 /* convert long to single precision real */
2184 rv.s = ieee754sp_flong(bits);
2185 rfmt = s_fmt;
2186 goto copcsr;
2187 case fcvtd_op:
2188 /* convert long to double precision real */
2189 rv.d = ieee754dp_flong(bits);
2190 rfmt = d_fmt;
2191 goto copcsr;
2192 default: {
2193 /* Emulating the new CMP.condn.fmt R6 instruction */
2194 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2195 int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2196 union ieee754dp fs, ft;
2197
2198 if (!cpu_has_mips_r6 ||
2199 (MIPSInst_FUNC(ir) & 0x20))
2200 return SIGILL;
2201
2202 /* fmt is l_fmt for double precision so fix it */
2203 rfmt = d_fmt;
2204 /* default to false */
2205 rv.l = 0;
2206
2207 /* CMP.condn.D */
2208 DPFROMREG(fs, MIPSInst_FS(ir));
2209 DPFROMREG(ft, MIPSInst_FT(ir));
2210
2211 /* positive predicates */
2212 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2213 if (ieee754dp_cmp(fs, ft,
2214 cmptab[cmpop], sig))
2215 rv.l = -1LL; /* true, all 1s */
2216 if (sig &&
2217 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2218 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2219 else
2220 goto copcsr;
2221 } else {
2222 /* negative predicates */
2223 switch (cmpop) {
2224 case 1:
2225 case 2:
2226 case 3:
2227 if (ieee754dp_cmp(fs, ft,
2228 negative_cmptab[cmpop],
2229 sig))
2230 rv.l = -1LL; /* true, all 1s */
2231 if (sig &&
2232 ieee754_cxtest(IEEE754_INVALID_OPERATION))
2233 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2234 else
2235 goto copcsr;
2236 break;
2237 default:
2238 /* Reserved R6 ops */
2239 pr_err("Reserved MIPS R6 CMP.condn.D operation\n");
2240 return SIGILL;
2241 }
2242 }
2243 break;
2244 }
2245 }
2246 default:
2247 return SIGILL;
2248 }
2249
2250 /*
2251 * Update the fpu CSR register for this operation.
2252 * If an exception is required, generate a tidy SIGFPE exception,
2253 * without updating the result register.
2254 * Note: cause exception bits do not accumulate, they are rewritten
2255 * for each op; only the flag/sticky bits accumulate.
2256 */
2257 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
2258 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
2259 /*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */
2260 return SIGFPE;
2261 }
2262
2263 /*
2264 * Now we can safely write the result back to the register file.
2265 */
2266 switch (rfmt) {
2267 case -1:
2268
2269 if (cpu_has_mips_4_5_r)
2270 cbit = fpucondbit[MIPSInst_FD(ir) >> 2];
2271 else
2272 cbit = FPU_CSR_COND;
2273 if (rv.w)
2274 ctx->fcr31 |= cbit;
2275 else
2276 ctx->fcr31 &= ~cbit;
2277 break;
2278
2279 case d_fmt:
2280 DPTOREG(rv.d, MIPSInst_FD(ir));
2281 break;
2282 case s_fmt:
2283 SPTOREG(rv.s, MIPSInst_FD(ir));
2284 break;
2285 case w_fmt:
2286 SITOREG(rv.w, MIPSInst_FD(ir));
2287 break;
2288 case l_fmt:
2289 if (!cpu_has_mips_3_4_5_64_r2_r6)
2290 return SIGILL;
2291
2292 DITOREG(rv.l, MIPSInst_FD(ir));
2293 break;
2294 default:
2295 return SIGILL;
2296 }
2297
2298 return 0;
2299 }
2300
2301 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
2302 int has_fpu, void *__user *fault_addr)
2303 {
2304 unsigned long oldepc, prevepc;
2305 struct mm_decoded_insn dec_insn;
2306 u16 instr[4];
2307 u16 *instr_ptr;
2308 int sig = 0;
2309
2310 oldepc = xcp->cp0_epc;
2311 do {
2312 prevepc = xcp->cp0_epc;
2313
2314 if (get_isa16_mode(prevepc) && cpu_has_mmips) {
2315 /*
2316 * Get next 2 microMIPS instructions and convert them
2317 * into 32-bit instructions.
2318 */
2319 if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
2320 (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
2321 (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
2322 (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
2323 MIPS_FPU_EMU_INC_STATS(errors);
2324 return SIGBUS;
2325 }
2326 instr_ptr = instr;
2327
2328 /* Get first instruction. */
2329 if (mm_insn_16bit(*instr_ptr)) {
2330 /* Duplicate the half-word. */
2331 dec_insn.insn = (*instr_ptr << 16) |
2332 (*instr_ptr);
2333 /* 16-bit instruction. */
2334 dec_insn.pc_inc = 2;
2335 instr_ptr += 1;
2336 } else {
2337 dec_insn.insn = (*instr_ptr << 16) |
2338 *(instr_ptr+1);
2339 /* 32-bit instruction. */
2340 dec_insn.pc_inc = 4;
2341 instr_ptr += 2;
2342 }
2343 /* Get second instruction. */
2344 if (mm_insn_16bit(*instr_ptr)) {
2345 /* Duplicate the half-word. */
2346 dec_insn.next_insn = (*instr_ptr << 16) |
2347 (*instr_ptr);
2348 /* 16-bit instruction. */
2349 dec_insn.next_pc_inc = 2;
2350 } else {
2351 dec_insn.next_insn = (*instr_ptr << 16) |
2352 *(instr_ptr+1);
2353 /* 32-bit instruction. */
2354 dec_insn.next_pc_inc = 4;
2355 }
2356 dec_insn.micro_mips_mode = 1;
2357 } else {
2358 if ((get_user(dec_insn.insn,
2359 (mips_instruction __user *) xcp->cp0_epc)) ||
2360 (get_user(dec_insn.next_insn,
2361 (mips_instruction __user *)(xcp->cp0_epc+4)))) {
2362 MIPS_FPU_EMU_INC_STATS(errors);
2363 return SIGBUS;
2364 }
2365 dec_insn.pc_inc = 4;
2366 dec_insn.next_pc_inc = 4;
2367 dec_insn.micro_mips_mode = 0;
2368 }
2369
2370 if ((dec_insn.insn == 0) ||
2371 ((dec_insn.pc_inc == 2) &&
2372 ((dec_insn.insn & 0xffff) == MM_NOP16)))
2373 xcp->cp0_epc += dec_insn.pc_inc; /* Skip NOPs */
2374 else {
2375 /*
2376 * The 'ieee754_csr' is an alias of ctx->fcr31.
2377 * No need to copy ctx->fcr31 to ieee754_csr.
2378 */
2379 sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
2380 }
2381
2382 if (has_fpu)
2383 break;
2384 if (sig)
2385 break;
2386
2387 cond_resched();
2388 } while (xcp->cp0_epc > prevepc);
2389
2390 /* SIGILL indicates a non-fpu instruction */
2391 if (sig == SIGILL && xcp->cp0_epc != oldepc)
2392 /* but if EPC has advanced, then ignore it */
2393 sig = 0;
2394
2395 return sig;
2396 }
Linux kernel - Deliverables
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