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Linux 3.16-rc2
[linux/fpc-iii.git] / arch / powerpc / math-emu / math_efp.c
blob28337c9709ae60c326bbe9e67364b9fe3c19796e
1 /*
2 * arch/powerpc/math-emu/math_efp.c
3 *
4 * Copyright (C) 2006-2008, 2010 Freescale Semiconductor, Inc.
5 *
6 * Author: Ebony Zhu, <ebony.zhu@freescale.com>
7 * Yu Liu, <yu.liu@freescale.com>
8 *
9 * Derived from arch/alpha/math-emu/math.c
10 * arch/powerpc/math-emu/math.c
11 *
12 * Description:
13 * This file is the exception handler to make E500 SPE instructions
14 * fully comply with IEEE-754 floating point standard.
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
20 */
21
22 #include <linux/types.h>
23 #include <linux/prctl.h>
24
25 #include <asm/uaccess.h>
26 #include <asm/reg.h>
27
28 #define FP_EX_BOOKE_E500_SPE
29 #include <asm/sfp-machine.h>
30
31 #include <math-emu/soft-fp.h>
32 #include <math-emu/single.h>
33 #include <math-emu/double.h>
34
35 #define EFAPU 0x4
36
37 #define VCT 0x4
38 #define SPFP 0x6
39 #define DPFP 0x7
40
41 #define EFSADD 0x2c0
42 #define EFSSUB 0x2c1
43 #define EFSABS 0x2c4
44 #define EFSNABS 0x2c5
45 #define EFSNEG 0x2c6
46 #define EFSMUL 0x2c8
47 #define EFSDIV 0x2c9
48 #define EFSCMPGT 0x2cc
49 #define EFSCMPLT 0x2cd
50 #define EFSCMPEQ 0x2ce
51 #define EFSCFD 0x2cf
52 #define EFSCFSI 0x2d1
53 #define EFSCTUI 0x2d4
54 #define EFSCTSI 0x2d5
55 #define EFSCTUF 0x2d6
56 #define EFSCTSF 0x2d7
57 #define EFSCTUIZ 0x2d8
58 #define EFSCTSIZ 0x2da
59
60 #define EVFSADD 0x280
61 #define EVFSSUB 0x281
62 #define EVFSABS 0x284
63 #define EVFSNABS 0x285
64 #define EVFSNEG 0x286
65 #define EVFSMUL 0x288
66 #define EVFSDIV 0x289
67 #define EVFSCMPGT 0x28c
68 #define EVFSCMPLT 0x28d
69 #define EVFSCMPEQ 0x28e
70 #define EVFSCTUI 0x294
71 #define EVFSCTSI 0x295
72 #define EVFSCTUF 0x296
73 #define EVFSCTSF 0x297
74 #define EVFSCTUIZ 0x298
75 #define EVFSCTSIZ 0x29a
76
77 #define EFDADD 0x2e0
78 #define EFDSUB 0x2e1
79 #define EFDABS 0x2e4
80 #define EFDNABS 0x2e5
81 #define EFDNEG 0x2e6
82 #define EFDMUL 0x2e8
83 #define EFDDIV 0x2e9
84 #define EFDCTUIDZ 0x2ea
85 #define EFDCTSIDZ 0x2eb
86 #define EFDCMPGT 0x2ec
87 #define EFDCMPLT 0x2ed
88 #define EFDCMPEQ 0x2ee
89 #define EFDCFS 0x2ef
90 #define EFDCTUI 0x2f4
91 #define EFDCTSI 0x2f5
92 #define EFDCTUF 0x2f6
93 #define EFDCTSF 0x2f7
94 #define EFDCTUIZ 0x2f8
95 #define EFDCTSIZ 0x2fa
96
97 #define AB 2
98 #define XA 3
99 #define XB 4
100 #define XCR 5
101 #define NOTYPE 0
102
103 #define SIGN_BIT_S (1UL << 31)
104 #define SIGN_BIT_D (1ULL << 63)
105 #define FP_EX_MASK (FP_EX_INEXACT | FP_EX_INVALID | FP_EX_DIVZERO | \
106 FP_EX_UNDERFLOW | FP_EX_OVERFLOW)
107
108 static int have_e500_cpu_a005_erratum;
109
110 union dw_union {
111 u64 dp[1];
112 u32 wp[2];
113 };
114
115 static unsigned long insn_type(unsigned long speinsn)
116 {
117 unsigned long ret = NOTYPE;
118
119 switch (speinsn & 0x7ff) {
120 case EFSABS: ret = XA; break;
121 case EFSADD: ret = AB; break;
122 case EFSCFD: ret = XB; break;
123 case EFSCMPEQ: ret = XCR; break;
124 case EFSCMPGT: ret = XCR; break;
125 case EFSCMPLT: ret = XCR; break;
126 case EFSCTSF: ret = XB; break;
127 case EFSCTSI: ret = XB; break;
128 case EFSCTSIZ: ret = XB; break;
129 case EFSCTUF: ret = XB; break;
130 case EFSCTUI: ret = XB; break;
131 case EFSCTUIZ: ret = XB; break;
132 case EFSDIV: ret = AB; break;
133 case EFSMUL: ret = AB; break;
134 case EFSNABS: ret = XA; break;
135 case EFSNEG: ret = XA; break;
136 case EFSSUB: ret = AB; break;
137 case EFSCFSI: ret = XB; break;
138
139 case EVFSABS: ret = XA; break;
140 case EVFSADD: ret = AB; break;
141 case EVFSCMPEQ: ret = XCR; break;
142 case EVFSCMPGT: ret = XCR; break;
143 case EVFSCMPLT: ret = XCR; break;
144 case EVFSCTSF: ret = XB; break;
145 case EVFSCTSI: ret = XB; break;
146 case EVFSCTSIZ: ret = XB; break;
147 case EVFSCTUF: ret = XB; break;
148 case EVFSCTUI: ret = XB; break;
149 case EVFSCTUIZ: ret = XB; break;
150 case EVFSDIV: ret = AB; break;
151 case EVFSMUL: ret = AB; break;
152 case EVFSNABS: ret = XA; break;
153 case EVFSNEG: ret = XA; break;
154 case EVFSSUB: ret = AB; break;
155
156 case EFDABS: ret = XA; break;
157 case EFDADD: ret = AB; break;
158 case EFDCFS: ret = XB; break;
159 case EFDCMPEQ: ret = XCR; break;
160 case EFDCMPGT: ret = XCR; break;
161 case EFDCMPLT: ret = XCR; break;
162 case EFDCTSF: ret = XB; break;
163 case EFDCTSI: ret = XB; break;
164 case EFDCTSIDZ: ret = XB; break;
165 case EFDCTSIZ: ret = XB; break;
166 case EFDCTUF: ret = XB; break;
167 case EFDCTUI: ret = XB; break;
168 case EFDCTUIDZ: ret = XB; break;
169 case EFDCTUIZ: ret = XB; break;
170 case EFDDIV: ret = AB; break;
171 case EFDMUL: ret = AB; break;
172 case EFDNABS: ret = XA; break;
173 case EFDNEG: ret = XA; break;
174 case EFDSUB: ret = AB; break;
175 }
176
177 return ret;
178 }
179
180 int do_spe_mathemu(struct pt_regs *regs)
181 {
182 FP_DECL_EX;
183 int IR, cmp;
184
185 unsigned long type, func, fc, fa, fb, src, speinsn;
186 union dw_union vc, va, vb;
187
188 if (get_user(speinsn, (unsigned int __user *) regs->nip))
189 return -EFAULT;
190 if ((speinsn >> 26) != EFAPU)
191 return -EINVAL; /* not an spe instruction */
192
193 type = insn_type(speinsn);
194 if (type == NOTYPE)
195 goto illegal;
196
197 func = speinsn & 0x7ff;
198 fc = (speinsn >> 21) & 0x1f;
199 fa = (speinsn >> 16) & 0x1f;
200 fb = (speinsn >> 11) & 0x1f;
201 src = (speinsn >> 5) & 0x7;
202
203 vc.wp[0] = current->thread.evr[fc];
204 vc.wp[1] = regs->gpr[fc];
205 va.wp[0] = current->thread.evr[fa];
206 va.wp[1] = regs->gpr[fa];
207 vb.wp[0] = current->thread.evr[fb];
208 vb.wp[1] = regs->gpr[fb];
209
210 __FPU_FPSCR = mfspr(SPRN_SPEFSCR);
211
212 pr_debug("speinsn:%08lx spefscr:%08lx\n", speinsn, __FPU_FPSCR);
213 pr_debug("vc: %08x %08x\n", vc.wp[0], vc.wp[1]);
214 pr_debug("va: %08x %08x\n", va.wp[0], va.wp[1]);
215 pr_debug("vb: %08x %08x\n", vb.wp[0], vb.wp[1]);
216
217 switch (src) {
218 case SPFP: {
219 FP_DECL_S(SA); FP_DECL_S(SB); FP_DECL_S(SR);
220
221 switch (type) {
222 case AB:
223 case XCR:
224 FP_UNPACK_SP(SA, va.wp + 1);
225 case XB:
226 FP_UNPACK_SP(SB, vb.wp + 1);
227 break;
228 case XA:
229 FP_UNPACK_SP(SA, va.wp + 1);
230 break;
231 }
232
233 pr_debug("SA: %ld %08lx %ld (%ld)\n", SA_s, SA_f, SA_e, SA_c);
234 pr_debug("SB: %ld %08lx %ld (%ld)\n", SB_s, SB_f, SB_e, SB_c);
235
236 switch (func) {
237 case EFSABS:
238 vc.wp[1] = va.wp[1] & ~SIGN_BIT_S;
239 goto update_regs;
240
241 case EFSNABS:
242 vc.wp[1] = va.wp[1] | SIGN_BIT_S;
243 goto update_regs;
244
245 case EFSNEG:
246 vc.wp[1] = va.wp[1] ^ SIGN_BIT_S;
247 goto update_regs;
248
249 case EFSADD:
250 FP_ADD_S(SR, SA, SB);
251 goto pack_s;
252
253 case EFSSUB:
254 FP_SUB_S(SR, SA, SB);
255 goto pack_s;
256
257 case EFSMUL:
258 FP_MUL_S(SR, SA, SB);
259 goto pack_s;
260
261 case EFSDIV:
262 FP_DIV_S(SR, SA, SB);
263 goto pack_s;
264
265 case EFSCMPEQ:
266 cmp = 0;
267 goto cmp_s;
268
269 case EFSCMPGT:
270 cmp = 1;
271 goto cmp_s;
272
273 case EFSCMPLT:
274 cmp = -1;
275 goto cmp_s;
276
277 case EFSCTSF:
278 case EFSCTUF:
279 if (SB_c == FP_CLS_NAN) {
280 vc.wp[1] = 0;
281 FP_SET_EXCEPTION(FP_EX_INVALID);
282 } else {
283 SB_e += (func == EFSCTSF ? 31 : 32);
284 FP_TO_INT_ROUND_S(vc.wp[1], SB, 32,
285 (func == EFSCTSF));
286 }
287 goto update_regs;
288
289 case EFSCFD: {
290 FP_DECL_D(DB);
291 FP_CLEAR_EXCEPTIONS;
292 FP_UNPACK_DP(DB, vb.dp);
293
294 pr_debug("DB: %ld %08lx %08lx %ld (%ld)\n",
295 DB_s, DB_f1, DB_f0, DB_e, DB_c);
296
297 FP_CONV(S, D, 1, 2, SR, DB);
298 goto pack_s;
299 }
300
301 case EFSCTSI:
302 case EFSCTUI:
303 if (SB_c == FP_CLS_NAN) {
304 vc.wp[1] = 0;
305 FP_SET_EXCEPTION(FP_EX_INVALID);
306 } else {
307 FP_TO_INT_ROUND_S(vc.wp[1], SB, 32,
308 ((func & 0x3) != 0));
309 }
310 goto update_regs;
311
312 case EFSCTSIZ:
313 case EFSCTUIZ:
314 if (SB_c == FP_CLS_NAN) {
315 vc.wp[1] = 0;
316 FP_SET_EXCEPTION(FP_EX_INVALID);
317 } else {
318 FP_TO_INT_S(vc.wp[1], SB, 32,
319 ((func & 0x3) != 0));
320 }
321 goto update_regs;
322
323 default:
324 goto illegal;
325 }
326 break;
327
328 pack_s:
329 pr_debug("SR: %ld %08lx %ld (%ld)\n", SR_s, SR_f, SR_e, SR_c);
330
331 FP_PACK_SP(vc.wp + 1, SR);
332 goto update_regs;
333
334 cmp_s:
335 FP_CMP_S(IR, SA, SB, 3);
336 if (IR == 3 && (FP_ISSIGNAN_S(SA) || FP_ISSIGNAN_S(SB)))
337 FP_SET_EXCEPTION(FP_EX_INVALID);
338 if (IR == cmp) {
339 IR = 0x4;
340 } else {
341 IR = 0;
342 }
343 goto update_ccr;
344 }
345
346 case DPFP: {
347 FP_DECL_D(DA); FP_DECL_D(DB); FP_DECL_D(DR);
348
349 switch (type) {
350 case AB:
351 case XCR:
352 FP_UNPACK_DP(DA, va.dp);
353 case XB:
354 FP_UNPACK_DP(DB, vb.dp);
355 break;
356 case XA:
357 FP_UNPACK_DP(DA, va.dp);
358 break;
359 }
360
361 pr_debug("DA: %ld %08lx %08lx %ld (%ld)\n",
362 DA_s, DA_f1, DA_f0, DA_e, DA_c);
363 pr_debug("DB: %ld %08lx %08lx %ld (%ld)\n",
364 DB_s, DB_f1, DB_f0, DB_e, DB_c);
365
366 switch (func) {
367 case EFDABS:
368 vc.dp[0] = va.dp[0] & ~SIGN_BIT_D;
369 goto update_regs;
370
371 case EFDNABS:
372 vc.dp[0] = va.dp[0] | SIGN_BIT_D;
373 goto update_regs;
374
375 case EFDNEG:
376 vc.dp[0] = va.dp[0] ^ SIGN_BIT_D;
377 goto update_regs;
378
379 case EFDADD:
380 FP_ADD_D(DR, DA, DB);
381 goto pack_d;
382
383 case EFDSUB:
384 FP_SUB_D(DR, DA, DB);
385 goto pack_d;
386
387 case EFDMUL:
388 FP_MUL_D(DR, DA, DB);
389 goto pack_d;
390
391 case EFDDIV:
392 FP_DIV_D(DR, DA, DB);
393 goto pack_d;
394
395 case EFDCMPEQ:
396 cmp = 0;
397 goto cmp_d;
398
399 case EFDCMPGT:
400 cmp = 1;
401 goto cmp_d;
402
403 case EFDCMPLT:
404 cmp = -1;
405 goto cmp_d;
406
407 case EFDCTSF:
408 case EFDCTUF:
409 if (DB_c == FP_CLS_NAN) {
410 vc.wp[1] = 0;
411 FP_SET_EXCEPTION(FP_EX_INVALID);
412 } else {
413 DB_e += (func == EFDCTSF ? 31 : 32);
414 FP_TO_INT_ROUND_D(vc.wp[1], DB, 32,
415 (func == EFDCTSF));
416 }
417 goto update_regs;
418
419 case EFDCFS: {
420 FP_DECL_S(SB);
421 FP_CLEAR_EXCEPTIONS;
422 FP_UNPACK_SP(SB, vb.wp + 1);
423
424 pr_debug("SB: %ld %08lx %ld (%ld)\n",
425 SB_s, SB_f, SB_e, SB_c);
426
427 FP_CONV(D, S, 2, 1, DR, SB);
428 goto pack_d;
429 }
430
431 case EFDCTUIDZ:
432 case EFDCTSIDZ:
433 if (DB_c == FP_CLS_NAN) {
434 vc.dp[0] = 0;
435 FP_SET_EXCEPTION(FP_EX_INVALID);
436 } else {
437 FP_TO_INT_D(vc.dp[0], DB, 64,
438 ((func & 0x1) == 0));
439 }
440 goto update_regs;
441
442 case EFDCTUI:
443 case EFDCTSI:
444 if (DB_c == FP_CLS_NAN) {
445 vc.wp[1] = 0;
446 FP_SET_EXCEPTION(FP_EX_INVALID);
447 } else {
448 FP_TO_INT_ROUND_D(vc.wp[1], DB, 32,
449 ((func & 0x3) != 0));
450 }
451 goto update_regs;
452
453 case EFDCTUIZ:
454 case EFDCTSIZ:
455 if (DB_c == FP_CLS_NAN) {
456 vc.wp[1] = 0;
457 FP_SET_EXCEPTION(FP_EX_INVALID);
458 } else {
459 FP_TO_INT_D(vc.wp[1], DB, 32,
460 ((func & 0x3) != 0));
461 }
462 goto update_regs;
463
464 default:
465 goto illegal;
466 }
467 break;
468
469 pack_d:
470 pr_debug("DR: %ld %08lx %08lx %ld (%ld)\n",
471 DR_s, DR_f1, DR_f0, DR_e, DR_c);
472
473 FP_PACK_DP(vc.dp, DR);
474 goto update_regs;
475
476 cmp_d:
477 FP_CMP_D(IR, DA, DB, 3);
478 if (IR == 3 && (FP_ISSIGNAN_D(DA) || FP_ISSIGNAN_D(DB)))
479 FP_SET_EXCEPTION(FP_EX_INVALID);
480 if (IR == cmp) {
481 IR = 0x4;
482 } else {
483 IR = 0;
484 }
485 goto update_ccr;
486
487 }
488
489 case VCT: {
490 FP_DECL_S(SA0); FP_DECL_S(SB0); FP_DECL_S(SR0);
491 FP_DECL_S(SA1); FP_DECL_S(SB1); FP_DECL_S(SR1);
492 int IR0, IR1;
493
494 switch (type) {
495 case AB:
496 case XCR:
497 FP_UNPACK_SP(SA0, va.wp);
498 FP_UNPACK_SP(SA1, va.wp + 1);
499 case XB:
500 FP_UNPACK_SP(SB0, vb.wp);
501 FP_UNPACK_SP(SB1, vb.wp + 1);
502 break;
503 case XA:
504 FP_UNPACK_SP(SA0, va.wp);
505 FP_UNPACK_SP(SA1, va.wp + 1);
506 break;
507 }
508
509 pr_debug("SA0: %ld %08lx %ld (%ld)\n",
510 SA0_s, SA0_f, SA0_e, SA0_c);
511 pr_debug("SA1: %ld %08lx %ld (%ld)\n",
512 SA1_s, SA1_f, SA1_e, SA1_c);
513 pr_debug("SB0: %ld %08lx %ld (%ld)\n",
514 SB0_s, SB0_f, SB0_e, SB0_c);
515 pr_debug("SB1: %ld %08lx %ld (%ld)\n",
516 SB1_s, SB1_f, SB1_e, SB1_c);
517
518 switch (func) {
519 case EVFSABS:
520 vc.wp[0] = va.wp[0] & ~SIGN_BIT_S;
521 vc.wp[1] = va.wp[1] & ~SIGN_BIT_S;
522 goto update_regs;
523
524 case EVFSNABS:
525 vc.wp[0] = va.wp[0] | SIGN_BIT_S;
526 vc.wp[1] = va.wp[1] | SIGN_BIT_S;
527 goto update_regs;
528
529 case EVFSNEG:
530 vc.wp[0] = va.wp[0] ^ SIGN_BIT_S;
531 vc.wp[1] = va.wp[1] ^ SIGN_BIT_S;
532 goto update_regs;
533
534 case EVFSADD:
535 FP_ADD_S(SR0, SA0, SB0);
536 FP_ADD_S(SR1, SA1, SB1);
537 goto pack_vs;
538
539 case EVFSSUB:
540 FP_SUB_S(SR0, SA0, SB0);
541 FP_SUB_S(SR1, SA1, SB1);
542 goto pack_vs;
543
544 case EVFSMUL:
545 FP_MUL_S(SR0, SA0, SB0);
546 FP_MUL_S(SR1, SA1, SB1);
547 goto pack_vs;
548
549 case EVFSDIV:
550 FP_DIV_S(SR0, SA0, SB0);
551 FP_DIV_S(SR1, SA1, SB1);
552 goto pack_vs;
553
554 case EVFSCMPEQ:
555 cmp = 0;
556 goto cmp_vs;
557
558 case EVFSCMPGT:
559 cmp = 1;
560 goto cmp_vs;
561
562 case EVFSCMPLT:
563 cmp = -1;
564 goto cmp_vs;
565
566 case EVFSCTUF:
567 case EVFSCTSF:
568 if (SB0_c == FP_CLS_NAN) {
569 vc.wp[0] = 0;
570 FP_SET_EXCEPTION(FP_EX_INVALID);
571 } else {
572 SB0_e += (func == EVFSCTSF ? 31 : 32);
573 FP_TO_INT_ROUND_S(vc.wp[0], SB0, 32,
574 (func == EVFSCTSF));
575 }
576 if (SB1_c == FP_CLS_NAN) {
577 vc.wp[1] = 0;
578 FP_SET_EXCEPTION(FP_EX_INVALID);
579 } else {
580 SB1_e += (func == EVFSCTSF ? 31 : 32);
581 FP_TO_INT_ROUND_S(vc.wp[1], SB1, 32,
582 (func == EVFSCTSF));
583 }
584 goto update_regs;
585
586 case EVFSCTUI:
587 case EVFSCTSI:
588 if (SB0_c == FP_CLS_NAN) {
589 vc.wp[0] = 0;
590 FP_SET_EXCEPTION(FP_EX_INVALID);
591 } else {
592 FP_TO_INT_ROUND_S(vc.wp[0], SB0, 32,
593 ((func & 0x3) != 0));
594 }
595 if (SB1_c == FP_CLS_NAN) {
596 vc.wp[1] = 0;
597 FP_SET_EXCEPTION(FP_EX_INVALID);
598 } else {
599 FP_TO_INT_ROUND_S(vc.wp[1], SB1, 32,
600 ((func & 0x3) != 0));
601 }
602 goto update_regs;
603
604 case EVFSCTUIZ:
605 case EVFSCTSIZ:
606 if (SB0_c == FP_CLS_NAN) {
607 vc.wp[0] = 0;
608 FP_SET_EXCEPTION(FP_EX_INVALID);
609 } else {
610 FP_TO_INT_S(vc.wp[0], SB0, 32,
611 ((func & 0x3) != 0));
612 }
613 if (SB1_c == FP_CLS_NAN) {
614 vc.wp[1] = 0;
615 FP_SET_EXCEPTION(FP_EX_INVALID);
616 } else {
617 FP_TO_INT_S(vc.wp[1], SB1, 32,
618 ((func & 0x3) != 0));
619 }
620 goto update_regs;
621
622 default:
623 goto illegal;
624 }
625 break;
626
627 pack_vs:
628 pr_debug("SR0: %ld %08lx %ld (%ld)\n",
629 SR0_s, SR0_f, SR0_e, SR0_c);
630 pr_debug("SR1: %ld %08lx %ld (%ld)\n",
631 SR1_s, SR1_f, SR1_e, SR1_c);
632
633 FP_PACK_SP(vc.wp, SR0);
634 FP_PACK_SP(vc.wp + 1, SR1);
635 goto update_regs;
636
637 cmp_vs:
638 {
639 int ch, cl;
640
641 FP_CMP_S(IR0, SA0, SB0, 3);
642 FP_CMP_S(IR1, SA1, SB1, 3);
643 if (IR0 == 3 && (FP_ISSIGNAN_S(SA0) || FP_ISSIGNAN_S(SB0)))
644 FP_SET_EXCEPTION(FP_EX_INVALID);
645 if (IR1 == 3 && (FP_ISSIGNAN_S(SA1) || FP_ISSIGNAN_S(SB1)))
646 FP_SET_EXCEPTION(FP_EX_INVALID);
647 ch = (IR0 == cmp) ? 1 : 0;
648 cl = (IR1 == cmp) ? 1 : 0;
649 IR = (ch << 3) | (cl << 2) | ((ch | cl) << 1) |
650 ((ch & cl) << 0);
651 goto update_ccr;
652 }
653 }
654 default:
655 return -EINVAL;
656 }
657
658 update_ccr:
659 regs->ccr &= ~(15 << ((7 - ((speinsn >> 23) & 0x7)) << 2));
660 regs->ccr |= (IR << ((7 - ((speinsn >> 23) & 0x7)) << 2));
661
662 update_regs:
663 /*
664 * If the "invalid" exception sticky bit was set by the
665 * processor for non-finite input, but was not set before the
666 * instruction being emulated, clear it. Likewise for the
667 * "underflow" bit, which may have been set by the processor
668 * for exact underflow, not just inexact underflow when the
669 * flag should be set for IEEE 754 semantics. Other sticky
670 * exceptions will only be set by the processor when they are
671 * correct according to IEEE 754 semantics, and we must not
672 * clear sticky bits that were already set before the emulated
673 * instruction as they represent the user-visible sticky
674 * exception status. "inexact" traps to kernel are not
675 * required for IEEE semantics and are not enabled by default,
676 * so the "inexact" sticky bit may have been set by a previous
677 * instruction without the kernel being aware of it.
678 */
679 __FPU_FPSCR
680 &= ~(FP_EX_INVALID | FP_EX_UNDERFLOW) | current->thread.spefscr_last;
681 __FPU_FPSCR |= (FP_CUR_EXCEPTIONS & FP_EX_MASK);
682 mtspr(SPRN_SPEFSCR, __FPU_FPSCR);
683 current->thread.spefscr_last = __FPU_FPSCR;
684
685 current->thread.evr[fc] = vc.wp[0];
686 regs->gpr[fc] = vc.wp[1];
687
688 pr_debug("ccr = %08lx\n", regs->ccr);
689 pr_debug("cur exceptions = %08x spefscr = %08lx\n",
690 FP_CUR_EXCEPTIONS, __FPU_FPSCR);
691 pr_debug("vc: %08x %08x\n", vc.wp[0], vc.wp[1]);
692 pr_debug("va: %08x %08x\n", va.wp[0], va.wp[1]);
693 pr_debug("vb: %08x %08x\n", vb.wp[0], vb.wp[1]);
694
695 if (current->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) {
696 if ((FP_CUR_EXCEPTIONS & FP_EX_DIVZERO)
697 && (current->thread.fpexc_mode & PR_FP_EXC_DIV))
698 return 1;
699 if ((FP_CUR_EXCEPTIONS & FP_EX_OVERFLOW)
700 && (current->thread.fpexc_mode & PR_FP_EXC_OVF))
701 return 1;
702 if ((FP_CUR_EXCEPTIONS & FP_EX_UNDERFLOW)
703 && (current->thread.fpexc_mode & PR_FP_EXC_UND))
704 return 1;
705 if ((FP_CUR_EXCEPTIONS & FP_EX_INEXACT)
706 && (current->thread.fpexc_mode & PR_FP_EXC_RES))
707 return 1;
708 if ((FP_CUR_EXCEPTIONS & FP_EX_INVALID)
709 && (current->thread.fpexc_mode & PR_FP_EXC_INV))
710 return 1;
711 }
712 return 0;
713
714 illegal:
715 if (have_e500_cpu_a005_erratum) {
716 /* according to e500 cpu a005 erratum, reissue efp inst */
717 regs->nip -= 4;
718 pr_debug("re-issue efp inst: %08lx\n", speinsn);
719 return 0;
720 }
721
722 printk(KERN_ERR "\nOoops! IEEE-754 compliance handler encountered un-supported instruction.\ninst code: %08lx\n", speinsn);
723 return -ENOSYS;
724 }
725
726 int speround_handler(struct pt_regs *regs)
727 {
728 union dw_union fgpr;
729 int s_lo, s_hi;
730 int lo_inexact, hi_inexact;
731 int fp_result;
732 unsigned long speinsn, type, fb, fc, fptype, func;
733
734 if (get_user(speinsn, (unsigned int __user *) regs->nip))
735 return -EFAULT;
736 if ((speinsn >> 26) != 4)
737 return -EINVAL; /* not an spe instruction */
738
739 func = speinsn & 0x7ff;
740 type = insn_type(func);
741 if (type == XCR) return -ENOSYS;
742
743 __FPU_FPSCR = mfspr(SPRN_SPEFSCR);
744 pr_debug("speinsn:%08lx spefscr:%08lx\n", speinsn, __FPU_FPSCR);
745
746 fptype = (speinsn >> 5) & 0x7;
747
748 /* No need to round if the result is exact */
749 lo_inexact = __FPU_FPSCR & (SPEFSCR_FG | SPEFSCR_FX);
750 hi_inexact = __FPU_FPSCR & (SPEFSCR_FGH | SPEFSCR_FXH);
751 if (!(lo_inexact || (hi_inexact && fptype == VCT)))
752 return 0;
753
754 fc = (speinsn >> 21) & 0x1f;
755 s_lo = regs->gpr[fc] & SIGN_BIT_S;
756 s_hi = current->thread.evr[fc] & SIGN_BIT_S;
757 fgpr.wp[0] = current->thread.evr[fc];
758 fgpr.wp[1] = regs->gpr[fc];
759
760 fb = (speinsn >> 11) & 0x1f;
761 switch (func) {
762 case EFSCTUIZ:
763 case EFSCTSIZ:
764 case EVFSCTUIZ:
765 case EVFSCTSIZ:
766 case EFDCTUIDZ:
767 case EFDCTSIDZ:
768 case EFDCTUIZ:
769 case EFDCTSIZ:
770 /*
771 * These instructions always round to zero,
772 * independent of the rounding mode.
773 */
774 return 0;
775
776 case EFSCTUI:
777 case EFSCTUF:
778 case EVFSCTUI:
779 case EVFSCTUF:
780 case EFDCTUI:
781 case EFDCTUF:
782 fp_result = 0;
783 s_lo = 0;
784 s_hi = 0;
785 break;
786
787 case EFSCTSI:
788 case EFSCTSF:
789 fp_result = 0;
790 /* Recover the sign of a zero result if possible. */
791 if (fgpr.wp[1] == 0)
792 s_lo = regs->gpr[fb] & SIGN_BIT_S;
793 break;
794
795 case EVFSCTSI:
796 case EVFSCTSF:
797 fp_result = 0;
798 /* Recover the sign of a zero result if possible. */
799 if (fgpr.wp[1] == 0)
800 s_lo = regs->gpr[fb] & SIGN_BIT_S;
801 if (fgpr.wp[0] == 0)
802 s_hi = current->thread.evr[fb] & SIGN_BIT_S;
803 break;
804
805 case EFDCTSI:
806 case EFDCTSF:
807 fp_result = 0;
808 s_hi = s_lo;
809 /* Recover the sign of a zero result if possible. */
810 if (fgpr.wp[1] == 0)
811 s_hi = current->thread.evr[fb] & SIGN_BIT_S;
812 break;
813
814 default:
815 fp_result = 1;
816 break;
817 }
818
819 pr_debug("round fgpr: %08x %08x\n", fgpr.wp[0], fgpr.wp[1]);
820
821 switch (fptype) {
822 /* Since SPE instructions on E500 core can handle round to nearest
823 * and round toward zero with IEEE-754 complied, we just need
824 * to handle round toward +Inf and round toward -Inf by software.
825 */
826 case SPFP:
827 if ((FP_ROUNDMODE) == FP_RND_PINF) {
828 if (!s_lo) fgpr.wp[1]++; /* Z > 0, choose Z1 */
829 } else { /* round to -Inf */
830 if (s_lo) {
831 if (fp_result)
832 fgpr.wp[1]++; /* Z < 0, choose Z2 */
833 else
834 fgpr.wp[1]--; /* Z < 0, choose Z2 */
835 }
836 }
837 break;
838
839 case DPFP:
840 if (FP_ROUNDMODE == FP_RND_PINF) {
841 if (!s_hi) {
842 if (fp_result)
843 fgpr.dp[0]++; /* Z > 0, choose Z1 */
844 else
845 fgpr.wp[1]++; /* Z > 0, choose Z1 */
846 }
847 } else { /* round to -Inf */
848 if (s_hi) {
849 if (fp_result)
850 fgpr.dp[0]++; /* Z < 0, choose Z2 */
851 else
852 fgpr.wp[1]--; /* Z < 0, choose Z2 */
853 }
854 }
855 break;
856
857 case VCT:
858 if (FP_ROUNDMODE == FP_RND_PINF) {
859 if (lo_inexact && !s_lo)
860 fgpr.wp[1]++; /* Z_low > 0, choose Z1 */
861 if (hi_inexact && !s_hi)
862 fgpr.wp[0]++; /* Z_high word > 0, choose Z1 */
863 } else { /* round to -Inf */
864 if (lo_inexact && s_lo) {
865 if (fp_result)
866 fgpr.wp[1]++; /* Z_low < 0, choose Z2 */
867 else
868 fgpr.wp[1]--; /* Z_low < 0, choose Z2 */
869 }
870 if (hi_inexact && s_hi) {
871 if (fp_result)
872 fgpr.wp[0]++; /* Z_high < 0, choose Z2 */
873 else
874 fgpr.wp[0]--; /* Z_high < 0, choose Z2 */
875 }
876 }
877 break;
878
879 default:
880 return -EINVAL;
881 }
882
883 current->thread.evr[fc] = fgpr.wp[0];
884 regs->gpr[fc] = fgpr.wp[1];
885
886 pr_debug(" to fgpr: %08x %08x\n", fgpr.wp[0], fgpr.wp[1]);
887
888 if (current->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
889 return (current->thread.fpexc_mode & PR_FP_EXC_RES) ? 1 : 0;
890 return 0;
891 }
892
893 int __init spe_mathemu_init(void)
894 {
895 u32 pvr, maj, min;
896
897 pvr = mfspr(SPRN_PVR);
898
899 if ((PVR_VER(pvr) == PVR_VER_E500V1) ||
900 (PVR_VER(pvr) == PVR_VER_E500V2)) {
901 maj = PVR_MAJ(pvr);
902 min = PVR_MIN(pvr);
903
904 /*
905 * E500 revision below 1.1, 2.3, 3.1, 4.1, 5.1
906 * need cpu a005 errata workaround
907 */
908 switch (maj) {
909 case 1:
910 if (min < 1)
911 have_e500_cpu_a005_erratum = 1;
912 break;
913 case 2:
914 if (min < 3)
915 have_e500_cpu_a005_erratum = 1;
916 break;
917 case 3:
918 case 4:
919 case 5:
920 if (min < 1)
921 have_e500_cpu_a005_erratum = 1;
922 break;
923 default:
924 break;
925 }
926 }
927
928 return 0;
929 }
930
931 module_init(spe_mathemu_init);
Linux with added FPC-III support