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hugetlb: introduce generic version of hugetlb_free_pgd_range
[linux/fpc-iii.git] / arch / x86 / math-emu / errors.c
blob6b468517ab7167fcffd0fed7f4f0134e71f70b50
1 // SPDX-License-Identifier: GPL-2.0
2 /*---------------------------------------------------------------------------+
3 | errors.c |
4 | |
5 | The error handling functions for wm-FPU-emu |
6 | |
7 | Copyright (C) 1992,1993,1994,1996 |
8 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
9 | E-mail billm@jacobi.maths.monash.edu.au |
10 | |
11 | |
12 +---------------------------------------------------------------------------*/
13
14 /*---------------------------------------------------------------------------+
15 | Note: |
16 | The file contains code which accesses user memory. |
17 | Emulator static data may change when user memory is accessed, due to |
18 | other processes using the emulator while swapping is in progress. |
19 +---------------------------------------------------------------------------*/
20
21 #include <linux/signal.h>
22
23 #include <linux/uaccess.h>
24
25 #include "fpu_emu.h"
26 #include "fpu_system.h"
27 #include "exception.h"
28 #include "status_w.h"
29 #include "control_w.h"
30 #include "reg_constant.h"
31 #include "version.h"
32
33 /* */
34 #undef PRINT_MESSAGES
35 /* */
36
37 #if 0
38 void Un_impl(void)
39 {
40 u_char byte1, FPU_modrm;
41 unsigned long address = FPU_ORIG_EIP;
42
43 RE_ENTRANT_CHECK_OFF;
44 /* No need to check access_ok(), we have previously fetched these bytes. */
45 printk("Unimplemented FPU Opcode at eip=%p : ", (void __user *)address);
46 if (FPU_CS == __USER_CS) {
47 while (1) {
48 FPU_get_user(byte1, (u_char __user *) address);
49 if ((byte1 & 0xf8) == 0xd8)
50 break;
51 printk("[%02x]", byte1);
52 address++;
53 }
54 printk("%02x ", byte1);
55 FPU_get_user(FPU_modrm, 1 + (u_char __user *) address);
56
57 if (FPU_modrm >= 0300)
58 printk("%02x (%02x+%d)\n", FPU_modrm, FPU_modrm & 0xf8,
59 FPU_modrm & 7);
60 else
61 printk("/%d\n", (FPU_modrm >> 3) & 7);
62 } else {
63 printk("cs selector = %04x\n", FPU_CS);
64 }
65
66 RE_ENTRANT_CHECK_ON;
67
68 EXCEPTION(EX_Invalid);
69
70 }
71 #endif /* 0 */
72
73 /*
74 Called for opcodes which are illegal and which are known to result in a
75 SIGILL with a real 80486.
76 */
77 void FPU_illegal(void)
78 {
79 math_abort(FPU_info, SIGILL);
80 }
81
82 void FPU_printall(void)
83 {
84 int i;
85 static const char *tag_desc[] = { "Valid", "Zero", "ERROR", "Empty",
86 "DeNorm", "Inf", "NaN"
87 };
88 u_char byte1, FPU_modrm;
89 unsigned long address = FPU_ORIG_EIP;
90
91 RE_ENTRANT_CHECK_OFF;
92 /* No need to check access_ok(), we have previously fetched these bytes. */
93 printk("At %p:", (void *)address);
94 if (FPU_CS == __USER_CS) {
95 #define MAX_PRINTED_BYTES 20
96 for (i = 0; i < MAX_PRINTED_BYTES; i++) {
97 FPU_get_user(byte1, (u_char __user *) address);
98 if ((byte1 & 0xf8) == 0xd8) {
99 printk(" %02x", byte1);
100 break;
101 }
102 printk(" [%02x]", byte1);
103 address++;
104 }
105 if (i == MAX_PRINTED_BYTES)
106 printk(" [more..]\n");
107 else {
108 FPU_get_user(FPU_modrm, 1 + (u_char __user *) address);
109
110 if (FPU_modrm >= 0300)
111 printk(" %02x (%02x+%d)\n", FPU_modrm,
112 FPU_modrm & 0xf8, FPU_modrm & 7);
113 else
114 printk(" /%d, mod=%d rm=%d\n",
115 (FPU_modrm >> 3) & 7,
116 (FPU_modrm >> 6) & 3, FPU_modrm & 7);
117 }
118 } else {
119 printk("%04x\n", FPU_CS);
120 }
121
122 partial_status = status_word();
123
124 #ifdef DEBUGGING
125 if (partial_status & SW_Backward)
126 printk("SW: backward compatibility\n");
127 if (partial_status & SW_C3)
128 printk("SW: condition bit 3\n");
129 if (partial_status & SW_C2)
130 printk("SW: condition bit 2\n");
131 if (partial_status & SW_C1)
132 printk("SW: condition bit 1\n");
133 if (partial_status & SW_C0)
134 printk("SW: condition bit 0\n");
135 if (partial_status & SW_Summary)
136 printk("SW: exception summary\n");
137 if (partial_status & SW_Stack_Fault)
138 printk("SW: stack fault\n");
139 if (partial_status & SW_Precision)
140 printk("SW: loss of precision\n");
141 if (partial_status & SW_Underflow)
142 printk("SW: underflow\n");
143 if (partial_status & SW_Overflow)
144 printk("SW: overflow\n");
145 if (partial_status & SW_Zero_Div)
146 printk("SW: divide by zero\n");
147 if (partial_status & SW_Denorm_Op)
148 printk("SW: denormalized operand\n");
149 if (partial_status & SW_Invalid)
150 printk("SW: invalid operation\n");
151 #endif /* DEBUGGING */
152
153 printk(" SW: b=%d st=%d es=%d sf=%d cc=%d%d%d%d ef=%d%d%d%d%d%d\n", partial_status & 0x8000 ? 1 : 0, /* busy */
154 (partial_status & 0x3800) >> 11, /* stack top pointer */
155 partial_status & 0x80 ? 1 : 0, /* Error summary status */
156 partial_status & 0x40 ? 1 : 0, /* Stack flag */
157 partial_status & SW_C3 ? 1 : 0, partial_status & SW_C2 ? 1 : 0, /* cc */
158 partial_status & SW_C1 ? 1 : 0, partial_status & SW_C0 ? 1 : 0, /* cc */
159 partial_status & SW_Precision ? 1 : 0,
160 partial_status & SW_Underflow ? 1 : 0,
161 partial_status & SW_Overflow ? 1 : 0,
162 partial_status & SW_Zero_Div ? 1 : 0,
163 partial_status & SW_Denorm_Op ? 1 : 0,
164 partial_status & SW_Invalid ? 1 : 0);
165
166 printk(" CW: ic=%d rc=%d%d pc=%d%d iem=%d ef=%d%d%d%d%d%d\n",
167 control_word & 0x1000 ? 1 : 0,
168 (control_word & 0x800) >> 11, (control_word & 0x400) >> 10,
169 (control_word & 0x200) >> 9, (control_word & 0x100) >> 8,
170 control_word & 0x80 ? 1 : 0,
171 control_word & SW_Precision ? 1 : 0,
172 control_word & SW_Underflow ? 1 : 0,
173 control_word & SW_Overflow ? 1 : 0,
174 control_word & SW_Zero_Div ? 1 : 0,
175 control_word & SW_Denorm_Op ? 1 : 0,
176 control_word & SW_Invalid ? 1 : 0);
177
178 for (i = 0; i < 8; i++) {
179 FPU_REG *r = &st(i);
180 u_char tagi = FPU_gettagi(i);
181 switch (tagi) {
182 case TAG_Empty:
183 continue;
184 break;
185 case TAG_Zero:
186 case TAG_Special:
187 tagi = FPU_Special(r);
188 case TAG_Valid:
189 printk("st(%d) %c .%04lx %04lx %04lx %04lx e%+-6d ", i,
190 getsign(r) ? '-' : '+',
191 (long)(r->sigh >> 16),
192 (long)(r->sigh & 0xFFFF),
193 (long)(r->sigl >> 16),
194 (long)(r->sigl & 0xFFFF),
195 exponent(r) - EXP_BIAS + 1);
196 break;
197 default:
198 printk("Whoops! Error in errors.c: tag%d is %d ", i,
199 tagi);
200 continue;
201 break;
202 }
203 printk("%s\n", tag_desc[(int)(unsigned)tagi]);
204 }
205
206 RE_ENTRANT_CHECK_ON;
207
208 }
209
210 static struct {
211 int type;
212 const char *name;
213 } exception_names[] = {
214 {
215 EX_StackOver, "stack overflow"}, {
216 EX_StackUnder, "stack underflow"}, {
217 EX_Precision, "loss of precision"}, {
218 EX_Underflow, "underflow"}, {
219 EX_Overflow, "overflow"}, {
220 EX_ZeroDiv, "divide by zero"}, {
221 EX_Denormal, "denormalized operand"}, {
222 EX_Invalid, "invalid operation"}, {
223 EX_INTERNAL, "INTERNAL BUG in " FPU_VERSION}, {
224 0, NULL}
225 };
226
227 /*
228 EX_INTERNAL is always given with a code which indicates where the
229 error was detected.
230
231 Internal error types:
232 0x14 in fpu_etc.c
233 0x1nn in a *.c file:
234 0x101 in reg_add_sub.c
235 0x102 in reg_mul.c
236 0x104 in poly_atan.c
237 0x105 in reg_mul.c
238 0x107 in fpu_trig.c
239 0x108 in reg_compare.c
240 0x109 in reg_compare.c
241 0x110 in reg_add_sub.c
242 0x111 in fpe_entry.c
243 0x112 in fpu_trig.c
244 0x113 in errors.c
245 0x115 in fpu_trig.c
246 0x116 in fpu_trig.c
247 0x117 in fpu_trig.c
248 0x118 in fpu_trig.c
249 0x119 in fpu_trig.c
250 0x120 in poly_atan.c
251 0x121 in reg_compare.c
252 0x122 in reg_compare.c
253 0x123 in reg_compare.c
254 0x125 in fpu_trig.c
255 0x126 in fpu_entry.c
256 0x127 in poly_2xm1.c
257 0x128 in fpu_entry.c
258 0x129 in fpu_entry.c
259 0x130 in get_address.c
260 0x131 in get_address.c
261 0x132 in get_address.c
262 0x133 in get_address.c
263 0x140 in load_store.c
264 0x141 in load_store.c
265 0x150 in poly_sin.c
266 0x151 in poly_sin.c
267 0x160 in reg_ld_str.c
268 0x161 in reg_ld_str.c
269 0x162 in reg_ld_str.c
270 0x163 in reg_ld_str.c
271 0x164 in reg_ld_str.c
272 0x170 in fpu_tags.c
273 0x171 in fpu_tags.c
274 0x172 in fpu_tags.c
275 0x180 in reg_convert.c
276 0x2nn in an *.S file:
277 0x201 in reg_u_add.S
278 0x202 in reg_u_div.S
279 0x203 in reg_u_div.S
280 0x204 in reg_u_div.S
281 0x205 in reg_u_mul.S
282 0x206 in reg_u_sub.S
283 0x207 in wm_sqrt.S
284 0x208 in reg_div.S
285 0x209 in reg_u_sub.S
286 0x210 in reg_u_sub.S
287 0x211 in reg_u_sub.S
288 0x212 in reg_u_sub.S
289 0x213 in wm_sqrt.S
290 0x214 in wm_sqrt.S
291 0x215 in wm_sqrt.S
292 0x220 in reg_norm.S
293 0x221 in reg_norm.S
294 0x230 in reg_round.S
295 0x231 in reg_round.S
296 0x232 in reg_round.S
297 0x233 in reg_round.S
298 0x234 in reg_round.S
299 0x235 in reg_round.S
300 0x236 in reg_round.S
301 0x240 in div_Xsig.S
302 0x241 in div_Xsig.S
303 0x242 in div_Xsig.S
304 */
305
306 asmlinkage __visible void FPU_exception(int n)
307 {
308 int i, int_type;
309
310 int_type = 0; /* Needed only to stop compiler warnings */
311 if (n & EX_INTERNAL) {
312 int_type = n - EX_INTERNAL;
313 n = EX_INTERNAL;
314 /* Set lots of exception bits! */
315 partial_status |= (SW_Exc_Mask | SW_Summary | SW_Backward);
316 } else {
317 /* Extract only the bits which we use to set the status word */
318 n &= (SW_Exc_Mask);
319 /* Set the corresponding exception bit */
320 partial_status |= n;
321 /* Set summary bits iff exception isn't masked */
322 if (partial_status & ~control_word & CW_Exceptions)
323 partial_status |= (SW_Summary | SW_Backward);
324 if (n & (SW_Stack_Fault | EX_Precision)) {
325 if (!(n & SW_C1))
326 /* This bit distinguishes over- from underflow for a stack fault,
327 and roundup from round-down for precision loss. */
328 partial_status &= ~SW_C1;
329 }
330 }
331
332 RE_ENTRANT_CHECK_OFF;
333 if ((~control_word & n & CW_Exceptions) || (n == EX_INTERNAL)) {
334 /* Get a name string for error reporting */
335 for (i = 0; exception_names[i].type; i++)
336 if ((exception_names[i].type & n) ==
337 exception_names[i].type)
338 break;
339
340 if (exception_names[i].type) {
341 #ifdef PRINT_MESSAGES
342 printk("FP Exception: %s!\n", exception_names[i].name);
343 #endif /* PRINT_MESSAGES */
344 } else
345 printk("FPU emulator: Unknown Exception: 0x%04x!\n", n);
346
347 if (n == EX_INTERNAL) {
348 printk("FPU emulator: Internal error type 0x%04x\n",
349 int_type);
350 FPU_printall();
351 }
352 #ifdef PRINT_MESSAGES
353 else
354 FPU_printall();
355 #endif /* PRINT_MESSAGES */
356
357 /*
358 * The 80486 generates an interrupt on the next non-control FPU
359 * instruction. So we need some means of flagging it.
360 * We use the ES (Error Summary) bit for this.
361 */
362 }
363 RE_ENTRANT_CHECK_ON;
364
365 #ifdef __DEBUG__
366 math_abort(FPU_info, SIGFPE);
367 #endif /* __DEBUG__ */
368
369 }
370
371 /* Real operation attempted on a NaN. */
372 /* Returns < 0 if the exception is unmasked */
373 int real_1op_NaN(FPU_REG *a)
374 {
375 int signalling, isNaN;
376
377 isNaN = (exponent(a) == EXP_OVER) && (a->sigh & 0x80000000);
378
379 /* The default result for the case of two "equal" NaNs (signs may
380 differ) is chosen to reproduce 80486 behaviour */
381 signalling = isNaN && !(a->sigh & 0x40000000);
382
383 if (!signalling) {
384 if (!isNaN) { /* pseudo-NaN, or other unsupported? */
385 if (control_word & CW_Invalid) {
386 /* Masked response */
387 reg_copy(&CONST_QNaN, a);
388 }
389 EXCEPTION(EX_Invalid);
390 return (!(control_word & CW_Invalid) ? FPU_Exception :
391 0) | TAG_Special;
392 }
393 return TAG_Special;
394 }
395
396 if (control_word & CW_Invalid) {
397 /* The masked response */
398 if (!(a->sigh & 0x80000000)) { /* pseudo-NaN ? */
399 reg_copy(&CONST_QNaN, a);
400 }
401 /* ensure a Quiet NaN */
402 a->sigh |= 0x40000000;
403 }
404
405 EXCEPTION(EX_Invalid);
406
407 return (!(control_word & CW_Invalid) ? FPU_Exception : 0) | TAG_Special;
408 }
409
410 /* Real operation attempted on two operands, one a NaN. */
411 /* Returns < 0 if the exception is unmasked */
412 int real_2op_NaN(FPU_REG const *b, u_char tagb,
413 int deststnr, FPU_REG const *defaultNaN)
414 {
415 FPU_REG *dest = &st(deststnr);
416 FPU_REG const *a = dest;
417 u_char taga = FPU_gettagi(deststnr);
418 FPU_REG const *x;
419 int signalling, unsupported;
420
421 if (taga == TAG_Special)
422 taga = FPU_Special(a);
423 if (tagb == TAG_Special)
424 tagb = FPU_Special(b);
425
426 /* TW_NaN is also used for unsupported data types. */
427 unsupported = ((taga == TW_NaN)
428 && !((exponent(a) == EXP_OVER)
429 && (a->sigh & 0x80000000)))
430 || ((tagb == TW_NaN)
431 && !((exponent(b) == EXP_OVER) && (b->sigh & 0x80000000)));
432 if (unsupported) {
433 if (control_word & CW_Invalid) {
434 /* Masked response */
435 FPU_copy_to_regi(&CONST_QNaN, TAG_Special, deststnr);
436 }
437 EXCEPTION(EX_Invalid);
438 return (!(control_word & CW_Invalid) ? FPU_Exception : 0) |
439 TAG_Special;
440 }
441
442 if (taga == TW_NaN) {
443 x = a;
444 if (tagb == TW_NaN) {
445 signalling = !(a->sigh & b->sigh & 0x40000000);
446 if (significand(b) > significand(a))
447 x = b;
448 else if (significand(b) == significand(a)) {
449 /* The default result for the case of two "equal" NaNs (signs may
450 differ) is chosen to reproduce 80486 behaviour */
451 x = defaultNaN;
452 }
453 } else {
454 /* return the quiet version of the NaN in a */
455 signalling = !(a->sigh & 0x40000000);
456 }
457 } else
458 #ifdef PARANOID
459 if (tagb == TW_NaN)
460 #endif /* PARANOID */
461 {
462 signalling = !(b->sigh & 0x40000000);
463 x = b;
464 }
465 #ifdef PARANOID
466 else {
467 signalling = 0;
468 EXCEPTION(EX_INTERNAL | 0x113);
469 x = &CONST_QNaN;
470 }
471 #endif /* PARANOID */
472
473 if ((!signalling) || (control_word & CW_Invalid)) {
474 if (!x)
475 x = b;
476
477 if (!(x->sigh & 0x80000000)) /* pseudo-NaN ? */
478 x = &CONST_QNaN;
479
480 FPU_copy_to_regi(x, TAG_Special, deststnr);
481
482 if (!signalling)
483 return TAG_Special;
484
485 /* ensure a Quiet NaN */
486 dest->sigh |= 0x40000000;
487 }
488
489 EXCEPTION(EX_Invalid);
490
491 return (!(control_word & CW_Invalid) ? FPU_Exception : 0) | TAG_Special;
492 }
493
494 /* Invalid arith operation on Valid registers */
495 /* Returns < 0 if the exception is unmasked */
496 asmlinkage __visible int arith_invalid(int deststnr)
497 {
498
499 EXCEPTION(EX_Invalid);
500
501 if (control_word & CW_Invalid) {
502 /* The masked response */
503 FPU_copy_to_regi(&CONST_QNaN, TAG_Special, deststnr);
504 }
505
506 return (!(control_word & CW_Invalid) ? FPU_Exception : 0) | TAG_Valid;
507
508 }
509
510 /* Divide a finite number by zero */
511 asmlinkage __visible int FPU_divide_by_zero(int deststnr, u_char sign)
512 {
513 FPU_REG *dest = &st(deststnr);
514 int tag = TAG_Valid;
515
516 if (control_word & CW_ZeroDiv) {
517 /* The masked response */
518 FPU_copy_to_regi(&CONST_INF, TAG_Special, deststnr);
519 setsign(dest, sign);
520 tag = TAG_Special;
521 }
522
523 EXCEPTION(EX_ZeroDiv);
524
525 return (!(control_word & CW_ZeroDiv) ? FPU_Exception : 0) | tag;
526
527 }
528
529 /* This may be called often, so keep it lean */
530 int set_precision_flag(int flags)
531 {
532 if (control_word & CW_Precision) {
533 partial_status &= ~(SW_C1 & flags);
534 partial_status |= flags; /* The masked response */
535 return 0;
536 } else {
537 EXCEPTION(flags);
538 return 1;
539 }
540 }
541
542 /* This may be called often, so keep it lean */
543 asmlinkage __visible void set_precision_flag_up(void)
544 {
545 if (control_word & CW_Precision)
546 partial_status |= (SW_Precision | SW_C1); /* The masked response */
547 else
548 EXCEPTION(EX_Precision | SW_C1);
549 }
550
551 /* This may be called often, so keep it lean */
552 asmlinkage __visible void set_precision_flag_down(void)
553 {
554 if (control_word & CW_Precision) { /* The masked response */
555 partial_status &= ~SW_C1;
556 partial_status |= SW_Precision;
557 } else
558 EXCEPTION(EX_Precision);
559 }
560
561 asmlinkage __visible int denormal_operand(void)
562 {
563 if (control_word & CW_Denormal) { /* The masked response */
564 partial_status |= SW_Denorm_Op;
565 return TAG_Special;
566 } else {
567 EXCEPTION(EX_Denormal);
568 return TAG_Special | FPU_Exception;
569 }
570 }
571
572 asmlinkage __visible int arith_overflow(FPU_REG *dest)
573 {
574 int tag = TAG_Valid;
575
576 if (control_word & CW_Overflow) {
577 /* The masked response */
578 /* ###### The response here depends upon the rounding mode */
579 reg_copy(&CONST_INF, dest);
580 tag = TAG_Special;
581 } else {
582 /* Subtract the magic number from the exponent */
583 addexponent(dest, (-3 * (1 << 13)));
584 }
585
586 EXCEPTION(EX_Overflow);
587 if (control_word & CW_Overflow) {
588 /* The overflow exception is masked. */
589 /* By definition, precision is lost.
590 The roundup bit (C1) is also set because we have
591 "rounded" upwards to Infinity. */
592 EXCEPTION(EX_Precision | SW_C1);
593 return tag;
594 }
595
596 return tag;
597
598 }
599
600 asmlinkage __visible int arith_underflow(FPU_REG *dest)
601 {
602 int tag = TAG_Valid;
603
604 if (control_word & CW_Underflow) {
605 /* The masked response */
606 if (exponent16(dest) <= EXP_UNDER - 63) {
607 reg_copy(&CONST_Z, dest);
608 partial_status &= ~SW_C1; /* Round down. */
609 tag = TAG_Zero;
610 } else {
611 stdexp(dest);
612 }
613 } else {
614 /* Add the magic number to the exponent. */
615 addexponent(dest, (3 * (1 << 13)) + EXTENDED_Ebias);
616 }
617
618 EXCEPTION(EX_Underflow);
619 if (control_word & CW_Underflow) {
620 /* The underflow exception is masked. */
621 EXCEPTION(EX_Precision);
622 return tag;
623 }
624
625 return tag;
626
627 }
628
629 void FPU_stack_overflow(void)
630 {
631
632 if (control_word & CW_Invalid) {
633 /* The masked response */
634 top--;
635 FPU_copy_to_reg0(&CONST_QNaN, TAG_Special);
636 }
637
638 EXCEPTION(EX_StackOver);
639
640 return;
641
642 }
643
644 void FPU_stack_underflow(void)
645 {
646
647 if (control_word & CW_Invalid) {
648 /* The masked response */
649 FPU_copy_to_reg0(&CONST_QNaN, TAG_Special);
650 }
651
652 EXCEPTION(EX_StackUnder);
653
654 return;
655
656 }
657
658 void FPU_stack_underflow_i(int i)
659 {
660
661 if (control_word & CW_Invalid) {
662 /* The masked response */
663 FPU_copy_to_regi(&CONST_QNaN, TAG_Special, i);
664 }
665
666 EXCEPTION(EX_StackUnder);
667
668 return;
669
670 }
671
672 void FPU_stack_underflow_pop(int i)
673 {
674
675 if (control_word & CW_Invalid) {
676 /* The masked response */
677 FPU_copy_to_regi(&CONST_QNaN, TAG_Special, i);
678 FPU_pop();
679 }
680
681 EXCEPTION(EX_StackUnder);
682
683 return;
684
685 }
Linux with added FPC-III support