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1/*
2 * Save/restore floating point context for signal handlers.
3 *
4 * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
9 *
10 * FIXME! These routines can be optimized in big endian case.
11 */
12#include <linux/sched.h>
13#include <linux/signal.h>
14#include <asm/processor.h>
15#include <asm/io.h>
16#include <asm/fpu.h>
17#include <asm/traps.h>
18
19/* The PR (precision) bit in the FP Status Register must be clear when
20 * an frchg instruction is executed, otherwise the instruction is undefined.
21 * Executing frchg with PR set causes a trap on some SH4 implementations.
22 */
23
24#define FPSCR_RCHG 0x00000000
25
26
27/*
28 * Save FPU registers onto task structure.
29 */
30void save_fpu(struct task_struct *tsk)
31{
32 unsigned long dummy;
33
34 enable_fpu();
35 asm volatile("sts.l fpul, @-%0\n\t"
36 "sts.l fpscr, @-%0\n\t"
37 "fmov.s fr15, @-%0\n\t"
38 "fmov.s fr14, @-%0\n\t"
39 "fmov.s fr13, @-%0\n\t"
40 "fmov.s fr12, @-%0\n\t"
41 "fmov.s fr11, @-%0\n\t"
42 "fmov.s fr10, @-%0\n\t"
43 "fmov.s fr9, @-%0\n\t"
44 "fmov.s fr8, @-%0\n\t"
45 "fmov.s fr7, @-%0\n\t"
46 "fmov.s fr6, @-%0\n\t"
47 "fmov.s fr5, @-%0\n\t"
48 "fmov.s fr4, @-%0\n\t"
49 "fmov.s fr3, @-%0\n\t"
50 "fmov.s fr2, @-%0\n\t"
51 "fmov.s fr1, @-%0\n\t"
52 "fmov.s fr0, @-%0\n\t"
53 "lds %3, fpscr\n\t"
54 : "=r" (dummy)
55 : "0" ((char *)(&tsk->thread.xstate->hardfpu.status)),
56 "r" (FPSCR_RCHG),
57 "r" (FPSCR_INIT)
58 : "memory");
59
60 disable_fpu();
61}
62
63void restore_fpu(struct task_struct *tsk)
64{
65 unsigned long dummy;
66
67 enable_fpu();
68 asm volatile("fmov.s @%0+, fr0\n\t"
69 "fmov.s @%0+, fr1\n\t"
70 "fmov.s @%0+, fr2\n\t"
71 "fmov.s @%0+, fr3\n\t"
72 "fmov.s @%0+, fr4\n\t"
73 "fmov.s @%0+, fr5\n\t"
74 "fmov.s @%0+, fr6\n\t"
75 "fmov.s @%0+, fr7\n\t"
76 "fmov.s @%0+, fr8\n\t"
77 "fmov.s @%0+, fr9\n\t"
78 "fmov.s @%0+, fr10\n\t"
79 "fmov.s @%0+, fr11\n\t"
80 "fmov.s @%0+, fr12\n\t"
81 "fmov.s @%0+, fr13\n\t"
82 "fmov.s @%0+, fr14\n\t"
83 "fmov.s @%0+, fr15\n\t"
84 "lds.l @%0+, fpscr\n\t"
85 "lds.l @%0+, fpul\n\t"
86 : "=r" (dummy)
87 : "0" (tsk->thread.xstate), "r" (FPSCR_RCHG)
88 : "memory");
89 disable_fpu();
90}
91
92/*
93 * Emulate arithmetic ops on denormalized number for some FPU insns.
94 */
95
96/* denormalized float * float */
97static int denormal_mulf(int hx, int hy)
98{
99 unsigned int ix, iy;
100 unsigned long long m, n;
101 int exp, w;
102
103 ix = hx & 0x7fffffff;
104 iy = hy & 0x7fffffff;
105 if (iy < 0x00800000 || ix == 0)
106 return ((hx ^ hy) & 0x80000000);
107
108 exp = (iy & 0x7f800000) >> 23;
109 ix &= 0x007fffff;
110 iy = (iy & 0x007fffff) | 0x00800000;
111 m = (unsigned long long)ix * iy;
112 n = m;
113 w = -1;
114 while (n) { n >>= 1; w++; }
115
116 /* FIXME: use guard bits */
117 exp += w - 126 - 46;
118 if (exp > 0)
119 ix = ((int) (m >> (w - 23)) & 0x007fffff) | (exp << 23);
120 else if (exp + 22 >= 0)
121 ix = (int) (m >> (w - 22 - exp)) & 0x007fffff;
122 else
123 ix = 0;
124
125 ix |= (hx ^ hy) & 0x80000000;
126 return ix;
127}
128
129/* denormalized double * double */
130static void mult64(unsigned long long x, unsigned long long y,
131 unsigned long long *highp, unsigned long long *lowp)
132{
133 unsigned long long sub0, sub1, sub2, sub3;
134 unsigned long long high, low;
135
136 sub0 = (x >> 32) * (unsigned long) (y >> 32);
137 sub1 = (x & 0xffffffffLL) * (unsigned long) (y >> 32);
138 sub2 = (x >> 32) * (unsigned long) (y & 0xffffffffLL);
139 sub3 = (x & 0xffffffffLL) * (unsigned long) (y & 0xffffffffLL);
140 low = sub3;
141 high = 0LL;
142 sub3 += (sub1 << 32);
143 if (low > sub3)
144 high++;
145 low = sub3;
146 sub3 += (sub2 << 32);
147 if (low > sub3)
148 high++;
149 low = sub3;
150 high += (sub1 >> 32) + (sub2 >> 32);
151 high += sub0;
152 *lowp = low;
153 *highp = high;
154}
155
156static inline long long rshift64(unsigned long long mh,
157 unsigned long long ml, int n)
158{
159 if (n >= 64)
160 return mh >> (n - 64);
161 return (mh << (64 - n)) | (ml >> n);
162}
163
164static long long denormal_muld(long long hx, long long hy)
165{
166 unsigned long long ix, iy;
167 unsigned long long mh, ml, nh, nl;
168 int exp, w;
169
170 ix = hx & 0x7fffffffffffffffLL;
171 iy = hy & 0x7fffffffffffffffLL;
172 if (iy < 0x0010000000000000LL || ix == 0)
173 return ((hx ^ hy) & 0x8000000000000000LL);
174
175 exp = (iy & 0x7ff0000000000000LL) >> 52;
176 ix &= 0x000fffffffffffffLL;
177 iy = (iy & 0x000fffffffffffffLL) | 0x0010000000000000LL;
178 mult64(ix, iy, &mh, &ml);
179 nh = mh;
180 nl = ml;
181 w = -1;
182 if (nh) {
183 while (nh) { nh >>= 1; w++;}
184 w += 64;
185 } else
186 while (nl) { nl >>= 1; w++;}
187
188 /* FIXME: use guard bits */
189 exp += w - 1022 - 52 * 2;
190 if (exp > 0)
191 ix = (rshift64(mh, ml, w - 52) & 0x000fffffffffffffLL)
192 | ((long long)exp << 52);
193 else if (exp + 51 >= 0)
194 ix = rshift64(mh, ml, w - 51 - exp) & 0x000fffffffffffffLL;
195 else
196 ix = 0;
197
198 ix |= (hx ^ hy) & 0x8000000000000000LL;
199 return ix;
200}
201
202/* ix - iy where iy: denormal and ix, iy >= 0 */
203static int denormal_subf1(unsigned int ix, unsigned int iy)
204{
205 int frac;
206 int exp;
207
208 if (ix < 0x00800000)
209 return ix - iy;
210
211 exp = (ix & 0x7f800000) >> 23;
212 if (exp - 1 > 31)
213 return ix;
214 iy >>= exp - 1;
215 if (iy == 0)
216 return ix;
217
218 frac = (ix & 0x007fffff) | 0x00800000;
219 frac -= iy;
220 while (frac < 0x00800000) {
221 if (--exp == 0)
222 return frac;
223 frac <<= 1;
224 }
225
226 return (exp << 23) | (frac & 0x007fffff);
227}
228
229/* ix + iy where iy: denormal and ix, iy >= 0 */
230static int denormal_addf1(unsigned int ix, unsigned int iy)
231{
232 int frac;
233 int exp;
234
235 if (ix < 0x00800000)
236 return ix + iy;
237
238 exp = (ix & 0x7f800000) >> 23;
239 if (exp - 1 > 31)
240 return ix;
241 iy >>= exp - 1;
242 if (iy == 0)
243 return ix;
244
245 frac = (ix & 0x007fffff) | 0x00800000;
246 frac += iy;
247 if (frac >= 0x01000000) {
248 frac >>= 1;
249 ++exp;
250 }
251
252 return (exp << 23) | (frac & 0x007fffff);
253}
254
255static int denormal_addf(int hx, int hy)
256{
257 unsigned int ix, iy;
258 int sign;
259
260 if ((hx ^ hy) & 0x80000000) {
261 sign = hx & 0x80000000;
262 ix = hx & 0x7fffffff;
263 iy = hy & 0x7fffffff;
264 if (iy < 0x00800000) {
265 ix = denormal_subf1(ix, iy);
266 if ((int) ix < 0) {
267 ix = -ix;
268 sign ^= 0x80000000;
269 }
270 } else {
271 ix = denormal_subf1(iy, ix);
272 sign ^= 0x80000000;
273 }
274 } else {
275 sign = hx & 0x80000000;
276 ix = hx & 0x7fffffff;
277 iy = hy & 0x7fffffff;
278 if (iy < 0x00800000)
279 ix = denormal_addf1(ix, iy);
280 else
281 ix = denormal_addf1(iy, ix);
282 }
283
284 return sign | ix;
285}
286
287/* ix - iy where iy: denormal and ix, iy >= 0 */
288static long long denormal_subd1(unsigned long long ix, unsigned long long iy)
289{
290 long long frac;
291 int exp;
292
293 if (ix < 0x0010000000000000LL)
294 return ix - iy;
295
296 exp = (ix & 0x7ff0000000000000LL) >> 52;
297 if (exp - 1 > 63)
298 return ix;
299 iy >>= exp - 1;
300 if (iy == 0)
301 return ix;
302
303 frac = (ix & 0x000fffffffffffffLL) | 0x0010000000000000LL;
304 frac -= iy;
305 while (frac < 0x0010000000000000LL) {
306 if (--exp == 0)
307 return frac;
308 frac <<= 1;
309 }
310
311 return ((long long)exp << 52) | (frac & 0x000fffffffffffffLL);
312}
313
314/* ix + iy where iy: denormal and ix, iy >= 0 */
315static long long denormal_addd1(unsigned long long ix, unsigned long long iy)
316{
317 long long frac;
318 long long exp;
319
320 if (ix < 0x0010000000000000LL)
321 return ix + iy;
322
323 exp = (ix & 0x7ff0000000000000LL) >> 52;
324 if (exp - 1 > 63)
325 return ix;
326 iy >>= exp - 1;
327 if (iy == 0)
328 return ix;
329
330 frac = (ix & 0x000fffffffffffffLL) | 0x0010000000000000LL;
331 frac += iy;
332 if (frac >= 0x0020000000000000LL) {
333 frac >>= 1;
334 ++exp;
335 }
336
337 return (exp << 52) | (frac & 0x000fffffffffffffLL);
338}
339
340static long long denormal_addd(long long hx, long long hy)
341{
342 unsigned long long ix, iy;
343 long long sign;
344
345 if ((hx ^ hy) & 0x8000000000000000LL) {
346 sign = hx & 0x8000000000000000LL;
347 ix = hx & 0x7fffffffffffffffLL;
348 iy = hy & 0x7fffffffffffffffLL;
349 if (iy < 0x0010000000000000LL) {
350 ix = denormal_subd1(ix, iy);
351 if ((int) ix < 0) {
352 ix = -ix;
353 sign ^= 0x8000000000000000LL;
354 }
355 } else {
356 ix = denormal_subd1(iy, ix);
357 sign ^= 0x8000000000000000LL;
358 }
359 } else {
360 sign = hx & 0x8000000000000000LL;
361 ix = hx & 0x7fffffffffffffffLL;
362 iy = hy & 0x7fffffffffffffffLL;
363 if (iy < 0x0010000000000000LL)
364 ix = denormal_addd1(ix, iy);
365 else
366 ix = denormal_addd1(iy, ix);
367 }
368
369 return sign | ix;
370}
371
372/**
373 * denormal_to_double - Given denormalized float number,
374 * store double float
375 *
376 * @fpu: Pointer to sh_fpu_hard structure
377 * @n: Index to FP register
378 */
379static void
380denormal_to_double (struct sh_fpu_hard_struct *fpu, int n)
381{
382 unsigned long du, dl;
383 unsigned long x = fpu->fpul;
384 int exp = 1023 - 126;
385
386 if (x != 0 && (x & 0x7f800000) == 0) {
387 du = (x & 0x80000000);
388 while ((x & 0x00800000) == 0) {
389 x <<= 1;
390 exp--;
391 }
392 x &= 0x007fffff;
393 du |= (exp << 20) | (x >> 3);
394 dl = x << 29;
395
396 fpu->fp_regs[n] = du;
397 fpu->fp_regs[n+1] = dl;
398 }
399}
400
401/**
402 * ieee_fpe_handler - Handle denormalized number exception
403 *
404 * @regs: Pointer to register structure
405 *
406 * Returns 1 when it's handled (should not cause exception).
407 */
408static int
409ieee_fpe_handler (struct pt_regs *regs)
410{
411 unsigned short insn = *(unsigned short *) regs->pc;
412 unsigned short finsn;
413 unsigned long nextpc;
414 int nib[4] = {
415 (insn >> 12) & 0xf,
416 (insn >> 8) & 0xf,
417 (insn >> 4) & 0xf,
418 insn & 0xf};
419
420 if (nib[0] == 0xb ||
421 (nib[0] == 0x4 && nib[2] == 0x0 && nib[3] == 0xb)) /* bsr & jsr */
422 regs->pr = regs->pc + 4;
423 if (nib[0] == 0xa || nib[0] == 0xb) { /* bra & bsr */
424 nextpc = regs->pc + 4 + ((short) ((insn & 0xfff) << 4) >> 3);
425 finsn = *(unsigned short *) (regs->pc + 2);
426 } else if (nib[0] == 0x8 && nib[1] == 0xd) { /* bt/s */
427 if (regs->sr & 1)
428 nextpc = regs->pc + 4 + ((char) (insn & 0xff) << 1);
429 else
430 nextpc = regs->pc + 4;
431 finsn = *(unsigned short *) (regs->pc + 2);
432 } else if (nib[0] == 0x8 && nib[1] == 0xf) { /* bf/s */
433 if (regs->sr & 1)
434 nextpc = regs->pc + 4;
435 else
436 nextpc = regs->pc + 4 + ((char) (insn & 0xff) << 1);
437 finsn = *(unsigned short *) (regs->pc + 2);
438 } else if (nib[0] == 0x4 && nib[3] == 0xb &&
439 (nib[2] == 0x0 || nib[2] == 0x2)) { /* jmp & jsr */
440 nextpc = regs->regs[nib[1]];
441 finsn = *(unsigned short *) (regs->pc + 2);
442 } else if (nib[0] == 0x0 && nib[3] == 0x3 &&
443 (nib[2] == 0x0 || nib[2] == 0x2)) { /* braf & bsrf */
444 nextpc = regs->pc + 4 + regs->regs[nib[1]];
445 finsn = *(unsigned short *) (regs->pc + 2);
446 } else if (insn == 0x000b) { /* rts */
447 nextpc = regs->pr;
448 finsn = *(unsigned short *) (regs->pc + 2);
449 } else {
450 nextpc = regs->pc + 2;
451 finsn = insn;
452 }
453
454#define FPSCR_FPU_ERROR (1 << 17)
455
456 if ((finsn & 0xf1ff) == 0xf0ad) { /* fcnvsd */
457 struct task_struct *tsk = current;
458
459 if ((tsk->thread.xstate->hardfpu.fpscr & FPSCR_FPU_ERROR)) {
460 /* FPU error */
461 denormal_to_double (&tsk->thread.xstate->hardfpu,
462 (finsn >> 8) & 0xf);
463 } else
464 return 0;
465
466 regs->pc = nextpc;
467 return 1;
468 } else if ((finsn & 0xf00f) == 0xf002) { /* fmul */
469 struct task_struct *tsk = current;
470 int fpscr;
471 int n, m, prec;
472 unsigned int hx, hy;
473
474 n = (finsn >> 8) & 0xf;
475 m = (finsn >> 4) & 0xf;
476 hx = tsk->thread.xstate->hardfpu.fp_regs[n];
477 hy = tsk->thread.xstate->hardfpu.fp_regs[m];
478 fpscr = tsk->thread.xstate->hardfpu.fpscr;
479 prec = fpscr & (1 << 19);
480
481 if ((fpscr & FPSCR_FPU_ERROR)
482 && (prec && ((hx & 0x7fffffff) < 0x00100000
483 || (hy & 0x7fffffff) < 0x00100000))) {
484 long long llx, lly;
485
486 /* FPU error because of denormal */
487 llx = ((long long) hx << 32)
488 | tsk->thread.xstate->hardfpu.fp_regs[n+1];
489 lly = ((long long) hy << 32)
490 | tsk->thread.xstate->hardfpu.fp_regs[m+1];
491 if ((hx & 0x7fffffff) >= 0x00100000)
492 llx = denormal_muld(lly, llx);
493 else
494 llx = denormal_muld(llx, lly);
495 tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
496 tsk->thread.xstate->hardfpu.fp_regs[n+1] = llx & 0xffffffff;
497 } else if ((fpscr & FPSCR_FPU_ERROR)
498 && (!prec && ((hx & 0x7fffffff) < 0x00800000
499 || (hy & 0x7fffffff) < 0x00800000))) {
500 /* FPU error because of denormal */
501 if ((hx & 0x7fffffff) >= 0x00800000)
502 hx = denormal_mulf(hy, hx);
503 else
504 hx = denormal_mulf(hx, hy);
505 tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
506 } else
507 return 0;
508
509 regs->pc = nextpc;
510 return 1;
511 } else if ((finsn & 0xf00e) == 0xf000) { /* fadd, fsub */
512 struct task_struct *tsk = current;
513 int fpscr;
514 int n, m, prec;
515 unsigned int hx, hy;
516
517 n = (finsn >> 8) & 0xf;
518 m = (finsn >> 4) & 0xf;
519 hx = tsk->thread.xstate->hardfpu.fp_regs[n];
520 hy = tsk->thread.xstate->hardfpu.fp_regs[m];
521 fpscr = tsk->thread.xstate->hardfpu.fpscr;
522 prec = fpscr & (1 << 19);
523
524 if ((fpscr & FPSCR_FPU_ERROR)
525 && (prec && ((hx & 0x7fffffff) < 0x00100000
526 || (hy & 0x7fffffff) < 0x00100000))) {
527 long long llx, lly;
528
529 /* FPU error because of denormal */
530 llx = ((long long) hx << 32)
531 | tsk->thread.xstate->hardfpu.fp_regs[n+1];
532 lly = ((long long) hy << 32)
533 | tsk->thread.xstate->hardfpu.fp_regs[m+1];
534 if ((finsn & 0xf00f) == 0xf000)
535 llx = denormal_addd(llx, lly);
536 else
537 llx = denormal_addd(llx, lly ^ (1LL << 63));
538 tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
539 tsk->thread.xstate->hardfpu.fp_regs[n+1] = llx & 0xffffffff;
540 } else if ((fpscr & FPSCR_FPU_ERROR)
541 && (!prec && ((hx & 0x7fffffff) < 0x00800000
542 || (hy & 0x7fffffff) < 0x00800000))) {
543 /* FPU error because of denormal */
544 if ((finsn & 0xf00f) == 0xf000)
545 hx = denormal_addf(hx, hy);
546 else
547 hx = denormal_addf(hx, hy ^ 0x80000000);
548 tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
549 } else
550 return 0;
551
552 regs->pc = nextpc;
553 return 1;
554 }
555
556 return 0;
557}
558
559BUILD_TRAP_HANDLER(fpu_error)
560{
561 struct task_struct *tsk = current;
562 TRAP_HANDLER_DECL;
563
564 __unlazy_fpu(tsk, regs);
565 if (ieee_fpe_handler(regs)) {
566 tsk->thread.xstate->hardfpu.fpscr &=
567 ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
568 grab_fpu(regs);
569 restore_fpu(tsk);
570 task_thread_info(tsk)->status |= TS_USEDFPU;
571 return;
572 }
573
574 force_sig(SIGFPE, tsk);
575}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Save/restore floating point context for signal handlers.
4 *
5 * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
6 *
7 * FIXME! These routines can be optimized in big endian case.
8 */
9#include <linux/sched/signal.h>
10#include <linux/signal.h>
11#include <asm/processor.h>
12#include <asm/io.h>
13#include <asm/fpu.h>
14#include <asm/traps.h>
15
16/* The PR (precision) bit in the FP Status Register must be clear when
17 * an frchg instruction is executed, otherwise the instruction is undefined.
18 * Executing frchg with PR set causes a trap on some SH4 implementations.
19 */
20
21#define FPSCR_RCHG 0x00000000
22
23
24/*
25 * Save FPU registers onto task structure.
26 */
27void save_fpu(struct task_struct *tsk)
28{
29 unsigned long dummy;
30
31 enable_fpu();
32 asm volatile("sts.l fpul, @-%0\n\t"
33 "sts.l fpscr, @-%0\n\t"
34 "fmov.s fr15, @-%0\n\t"
35 "fmov.s fr14, @-%0\n\t"
36 "fmov.s fr13, @-%0\n\t"
37 "fmov.s fr12, @-%0\n\t"
38 "fmov.s fr11, @-%0\n\t"
39 "fmov.s fr10, @-%0\n\t"
40 "fmov.s fr9, @-%0\n\t"
41 "fmov.s fr8, @-%0\n\t"
42 "fmov.s fr7, @-%0\n\t"
43 "fmov.s fr6, @-%0\n\t"
44 "fmov.s fr5, @-%0\n\t"
45 "fmov.s fr4, @-%0\n\t"
46 "fmov.s fr3, @-%0\n\t"
47 "fmov.s fr2, @-%0\n\t"
48 "fmov.s fr1, @-%0\n\t"
49 "fmov.s fr0, @-%0\n\t"
50 "lds %3, fpscr\n\t"
51 : "=r" (dummy)
52 : "0" ((char *)(&tsk->thread.xstate->hardfpu.status)),
53 "r" (FPSCR_RCHG),
54 "r" (FPSCR_INIT)
55 : "memory");
56
57 disable_fpu();
58}
59
60void restore_fpu(struct task_struct *tsk)
61{
62 unsigned long dummy;
63
64 enable_fpu();
65 asm volatile("fmov.s @%0+, fr0\n\t"
66 "fmov.s @%0+, fr1\n\t"
67 "fmov.s @%0+, fr2\n\t"
68 "fmov.s @%0+, fr3\n\t"
69 "fmov.s @%0+, fr4\n\t"
70 "fmov.s @%0+, fr5\n\t"
71 "fmov.s @%0+, fr6\n\t"
72 "fmov.s @%0+, fr7\n\t"
73 "fmov.s @%0+, fr8\n\t"
74 "fmov.s @%0+, fr9\n\t"
75 "fmov.s @%0+, fr10\n\t"
76 "fmov.s @%0+, fr11\n\t"
77 "fmov.s @%0+, fr12\n\t"
78 "fmov.s @%0+, fr13\n\t"
79 "fmov.s @%0+, fr14\n\t"
80 "fmov.s @%0+, fr15\n\t"
81 "lds.l @%0+, fpscr\n\t"
82 "lds.l @%0+, fpul\n\t"
83 : "=r" (dummy)
84 : "0" (tsk->thread.xstate), "r" (FPSCR_RCHG)
85 : "memory");
86 disable_fpu();
87}
88
89/*
90 * Emulate arithmetic ops on denormalized number for some FPU insns.
91 */
92
93/* denormalized float * float */
94static int denormal_mulf(int hx, int hy)
95{
96 unsigned int ix, iy;
97 unsigned long long m, n;
98 int exp, w;
99
100 ix = hx & 0x7fffffff;
101 iy = hy & 0x7fffffff;
102 if (iy < 0x00800000 || ix == 0)
103 return ((hx ^ hy) & 0x80000000);
104
105 exp = (iy & 0x7f800000) >> 23;
106 ix &= 0x007fffff;
107 iy = (iy & 0x007fffff) | 0x00800000;
108 m = (unsigned long long)ix * iy;
109 n = m;
110 w = -1;
111 while (n) { n >>= 1; w++; }
112
113 /* FIXME: use guard bits */
114 exp += w - 126 - 46;
115 if (exp > 0)
116 ix = ((int) (m >> (w - 23)) & 0x007fffff) | (exp << 23);
117 else if (exp + 22 >= 0)
118 ix = (int) (m >> (w - 22 - exp)) & 0x007fffff;
119 else
120 ix = 0;
121
122 ix |= (hx ^ hy) & 0x80000000;
123 return ix;
124}
125
126/* denormalized double * double */
127static void mult64(unsigned long long x, unsigned long long y,
128 unsigned long long *highp, unsigned long long *lowp)
129{
130 unsigned long long sub0, sub1, sub2, sub3;
131 unsigned long long high, low;
132
133 sub0 = (x >> 32) * (unsigned long) (y >> 32);
134 sub1 = (x & 0xffffffffLL) * (unsigned long) (y >> 32);
135 sub2 = (x >> 32) * (unsigned long) (y & 0xffffffffLL);
136 sub3 = (x & 0xffffffffLL) * (unsigned long) (y & 0xffffffffLL);
137 low = sub3;
138 high = 0LL;
139 sub3 += (sub1 << 32);
140 if (low > sub3)
141 high++;
142 low = sub3;
143 sub3 += (sub2 << 32);
144 if (low > sub3)
145 high++;
146 low = sub3;
147 high += (sub1 >> 32) + (sub2 >> 32);
148 high += sub0;
149 *lowp = low;
150 *highp = high;
151}
152
153static inline long long rshift64(unsigned long long mh,
154 unsigned long long ml, int n)
155{
156 if (n >= 64)
157 return mh >> (n - 64);
158 return (mh << (64 - n)) | (ml >> n);
159}
160
161static long long denormal_muld(long long hx, long long hy)
162{
163 unsigned long long ix, iy;
164 unsigned long long mh, ml, nh, nl;
165 int exp, w;
166
167 ix = hx & 0x7fffffffffffffffLL;
168 iy = hy & 0x7fffffffffffffffLL;
169 if (iy < 0x0010000000000000LL || ix == 0)
170 return ((hx ^ hy) & 0x8000000000000000LL);
171
172 exp = (iy & 0x7ff0000000000000LL) >> 52;
173 ix &= 0x000fffffffffffffLL;
174 iy = (iy & 0x000fffffffffffffLL) | 0x0010000000000000LL;
175 mult64(ix, iy, &mh, &ml);
176 nh = mh;
177 nl = ml;
178 w = -1;
179 if (nh) {
180 while (nh) { nh >>= 1; w++;}
181 w += 64;
182 } else
183 while (nl) { nl >>= 1; w++;}
184
185 /* FIXME: use guard bits */
186 exp += w - 1022 - 52 * 2;
187 if (exp > 0)
188 ix = (rshift64(mh, ml, w - 52) & 0x000fffffffffffffLL)
189 | ((long long)exp << 52);
190 else if (exp + 51 >= 0)
191 ix = rshift64(mh, ml, w - 51 - exp) & 0x000fffffffffffffLL;
192 else
193 ix = 0;
194
195 ix |= (hx ^ hy) & 0x8000000000000000LL;
196 return ix;
197}
198
199/* ix - iy where iy: denormal and ix, iy >= 0 */
200static int denormal_subf1(unsigned int ix, unsigned int iy)
201{
202 int frac;
203 int exp;
204
205 if (ix < 0x00800000)
206 return ix - iy;
207
208 exp = (ix & 0x7f800000) >> 23;
209 if (exp - 1 > 31)
210 return ix;
211 iy >>= exp - 1;
212 if (iy == 0)
213 return ix;
214
215 frac = (ix & 0x007fffff) | 0x00800000;
216 frac -= iy;
217 while (frac < 0x00800000) {
218 if (--exp == 0)
219 return frac;
220 frac <<= 1;
221 }
222
223 return (exp << 23) | (frac & 0x007fffff);
224}
225
226/* ix + iy where iy: denormal and ix, iy >= 0 */
227static int denormal_addf1(unsigned int ix, unsigned int iy)
228{
229 int frac;
230 int exp;
231
232 if (ix < 0x00800000)
233 return ix + iy;
234
235 exp = (ix & 0x7f800000) >> 23;
236 if (exp - 1 > 31)
237 return ix;
238 iy >>= exp - 1;
239 if (iy == 0)
240 return ix;
241
242 frac = (ix & 0x007fffff) | 0x00800000;
243 frac += iy;
244 if (frac >= 0x01000000) {
245 frac >>= 1;
246 ++exp;
247 }
248
249 return (exp << 23) | (frac & 0x007fffff);
250}
251
252static int denormal_addf(int hx, int hy)
253{
254 unsigned int ix, iy;
255 int sign;
256
257 if ((hx ^ hy) & 0x80000000) {
258 sign = hx & 0x80000000;
259 ix = hx & 0x7fffffff;
260 iy = hy & 0x7fffffff;
261 if (iy < 0x00800000) {
262 ix = denormal_subf1(ix, iy);
263 if ((int) ix < 0) {
264 ix = -ix;
265 sign ^= 0x80000000;
266 }
267 } else {
268 ix = denormal_subf1(iy, ix);
269 sign ^= 0x80000000;
270 }
271 } else {
272 sign = hx & 0x80000000;
273 ix = hx & 0x7fffffff;
274 iy = hy & 0x7fffffff;
275 if (iy < 0x00800000)
276 ix = denormal_addf1(ix, iy);
277 else
278 ix = denormal_addf1(iy, ix);
279 }
280
281 return sign | ix;
282}
283
284/* ix - iy where iy: denormal and ix, iy >= 0 */
285static long long denormal_subd1(unsigned long long ix, unsigned long long iy)
286{
287 long long frac;
288 int exp;
289
290 if (ix < 0x0010000000000000LL)
291 return ix - iy;
292
293 exp = (ix & 0x7ff0000000000000LL) >> 52;
294 if (exp - 1 > 63)
295 return ix;
296 iy >>= exp - 1;
297 if (iy == 0)
298 return ix;
299
300 frac = (ix & 0x000fffffffffffffLL) | 0x0010000000000000LL;
301 frac -= iy;
302 while (frac < 0x0010000000000000LL) {
303 if (--exp == 0)
304 return frac;
305 frac <<= 1;
306 }
307
308 return ((long long)exp << 52) | (frac & 0x000fffffffffffffLL);
309}
310
311/* ix + iy where iy: denormal and ix, iy >= 0 */
312static long long denormal_addd1(unsigned long long ix, unsigned long long iy)
313{
314 long long frac;
315 long long exp;
316
317 if (ix < 0x0010000000000000LL)
318 return ix + iy;
319
320 exp = (ix & 0x7ff0000000000000LL) >> 52;
321 if (exp - 1 > 63)
322 return ix;
323 iy >>= exp - 1;
324 if (iy == 0)
325 return ix;
326
327 frac = (ix & 0x000fffffffffffffLL) | 0x0010000000000000LL;
328 frac += iy;
329 if (frac >= 0x0020000000000000LL) {
330 frac >>= 1;
331 ++exp;
332 }
333
334 return (exp << 52) | (frac & 0x000fffffffffffffLL);
335}
336
337static long long denormal_addd(long long hx, long long hy)
338{
339 unsigned long long ix, iy;
340 long long sign;
341
342 if ((hx ^ hy) & 0x8000000000000000LL) {
343 sign = hx & 0x8000000000000000LL;
344 ix = hx & 0x7fffffffffffffffLL;
345 iy = hy & 0x7fffffffffffffffLL;
346 if (iy < 0x0010000000000000LL) {
347 ix = denormal_subd1(ix, iy);
348 if ((int) ix < 0) {
349 ix = -ix;
350 sign ^= 0x8000000000000000LL;
351 }
352 } else {
353 ix = denormal_subd1(iy, ix);
354 sign ^= 0x8000000000000000LL;
355 }
356 } else {
357 sign = hx & 0x8000000000000000LL;
358 ix = hx & 0x7fffffffffffffffLL;
359 iy = hy & 0x7fffffffffffffffLL;
360 if (iy < 0x0010000000000000LL)
361 ix = denormal_addd1(ix, iy);
362 else
363 ix = denormal_addd1(iy, ix);
364 }
365
366 return sign | ix;
367}
368
369/**
370 * denormal_to_double - Given denormalized float number,
371 * store double float
372 *
373 * @fpu: Pointer to sh_fpu_hard structure
374 * @n: Index to FP register
375 */
376static void
377denormal_to_double (struct sh_fpu_hard_struct *fpu, int n)
378{
379 unsigned long du, dl;
380 unsigned long x = fpu->fpul;
381 int exp = 1023 - 126;
382
383 if (x != 0 && (x & 0x7f800000) == 0) {
384 du = (x & 0x80000000);
385 while ((x & 0x00800000) == 0) {
386 x <<= 1;
387 exp--;
388 }
389 x &= 0x007fffff;
390 du |= (exp << 20) | (x >> 3);
391 dl = x << 29;
392
393 fpu->fp_regs[n] = du;
394 fpu->fp_regs[n+1] = dl;
395 }
396}
397
398/**
399 * ieee_fpe_handler - Handle denormalized number exception
400 *
401 * @regs: Pointer to register structure
402 *
403 * Returns 1 when it's handled (should not cause exception).
404 */
405static int
406ieee_fpe_handler (struct pt_regs *regs)
407{
408 unsigned short insn = *(unsigned short *) regs->pc;
409 unsigned short finsn;
410 unsigned long nextpc;
411 int nib[4] = {
412 (insn >> 12) & 0xf,
413 (insn >> 8) & 0xf,
414 (insn >> 4) & 0xf,
415 insn & 0xf};
416
417 if (nib[0] == 0xb ||
418 (nib[0] == 0x4 && nib[2] == 0x0 && nib[3] == 0xb)) /* bsr & jsr */
419 regs->pr = regs->pc + 4;
420 if (nib[0] == 0xa || nib[0] == 0xb) { /* bra & bsr */
421 nextpc = regs->pc + 4 + ((short) ((insn & 0xfff) << 4) >> 3);
422 finsn = *(unsigned short *) (regs->pc + 2);
423 } else if (nib[0] == 0x8 && nib[1] == 0xd) { /* bt/s */
424 if (regs->sr & 1)
425 nextpc = regs->pc + 4 + ((char) (insn & 0xff) << 1);
426 else
427 nextpc = regs->pc + 4;
428 finsn = *(unsigned short *) (regs->pc + 2);
429 } else if (nib[0] == 0x8 && nib[1] == 0xf) { /* bf/s */
430 if (regs->sr & 1)
431 nextpc = regs->pc + 4;
432 else
433 nextpc = regs->pc + 4 + ((char) (insn & 0xff) << 1);
434 finsn = *(unsigned short *) (regs->pc + 2);
435 } else if (nib[0] == 0x4 && nib[3] == 0xb &&
436 (nib[2] == 0x0 || nib[2] == 0x2)) { /* jmp & jsr */
437 nextpc = regs->regs[nib[1]];
438 finsn = *(unsigned short *) (regs->pc + 2);
439 } else if (nib[0] == 0x0 && nib[3] == 0x3 &&
440 (nib[2] == 0x0 || nib[2] == 0x2)) { /* braf & bsrf */
441 nextpc = regs->pc + 4 + regs->regs[nib[1]];
442 finsn = *(unsigned short *) (regs->pc + 2);
443 } else if (insn == 0x000b) { /* rts */
444 nextpc = regs->pr;
445 finsn = *(unsigned short *) (regs->pc + 2);
446 } else {
447 nextpc = regs->pc + 2;
448 finsn = insn;
449 }
450
451#define FPSCR_FPU_ERROR (1 << 17)
452
453 if ((finsn & 0xf1ff) == 0xf0ad) { /* fcnvsd */
454 struct task_struct *tsk = current;
455
456 if ((tsk->thread.xstate->hardfpu.fpscr & FPSCR_FPU_ERROR)) {
457 /* FPU error */
458 denormal_to_double (&tsk->thread.xstate->hardfpu,
459 (finsn >> 8) & 0xf);
460 } else
461 return 0;
462
463 regs->pc = nextpc;
464 return 1;
465 } else if ((finsn & 0xf00f) == 0xf002) { /* fmul */
466 struct task_struct *tsk = current;
467 int fpscr;
468 int n, m, prec;
469 unsigned int hx, hy;
470
471 n = (finsn >> 8) & 0xf;
472 m = (finsn >> 4) & 0xf;
473 hx = tsk->thread.xstate->hardfpu.fp_regs[n];
474 hy = tsk->thread.xstate->hardfpu.fp_regs[m];
475 fpscr = tsk->thread.xstate->hardfpu.fpscr;
476 prec = fpscr & (1 << 19);
477
478 if ((fpscr & FPSCR_FPU_ERROR)
479 && (prec && ((hx & 0x7fffffff) < 0x00100000
480 || (hy & 0x7fffffff) < 0x00100000))) {
481 long long llx, lly;
482
483 /* FPU error because of denormal */
484 llx = ((long long) hx << 32)
485 | tsk->thread.xstate->hardfpu.fp_regs[n+1];
486 lly = ((long long) hy << 32)
487 | tsk->thread.xstate->hardfpu.fp_regs[m+1];
488 if ((hx & 0x7fffffff) >= 0x00100000)
489 llx = denormal_muld(lly, llx);
490 else
491 llx = denormal_muld(llx, lly);
492 tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
493 tsk->thread.xstate->hardfpu.fp_regs[n+1] = llx & 0xffffffff;
494 } else if ((fpscr & FPSCR_FPU_ERROR)
495 && (!prec && ((hx & 0x7fffffff) < 0x00800000
496 || (hy & 0x7fffffff) < 0x00800000))) {
497 /* FPU error because of denormal */
498 if ((hx & 0x7fffffff) >= 0x00800000)
499 hx = denormal_mulf(hy, hx);
500 else
501 hx = denormal_mulf(hx, hy);
502 tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
503 } else
504 return 0;
505
506 regs->pc = nextpc;
507 return 1;
508 } else if ((finsn & 0xf00e) == 0xf000) { /* fadd, fsub */
509 struct task_struct *tsk = current;
510 int fpscr;
511 int n, m, prec;
512 unsigned int hx, hy;
513
514 n = (finsn >> 8) & 0xf;
515 m = (finsn >> 4) & 0xf;
516 hx = tsk->thread.xstate->hardfpu.fp_regs[n];
517 hy = tsk->thread.xstate->hardfpu.fp_regs[m];
518 fpscr = tsk->thread.xstate->hardfpu.fpscr;
519 prec = fpscr & (1 << 19);
520
521 if ((fpscr & FPSCR_FPU_ERROR)
522 && (prec && ((hx & 0x7fffffff) < 0x00100000
523 || (hy & 0x7fffffff) < 0x00100000))) {
524 long long llx, lly;
525
526 /* FPU error because of denormal */
527 llx = ((long long) hx << 32)
528 | tsk->thread.xstate->hardfpu.fp_regs[n+1];
529 lly = ((long long) hy << 32)
530 | tsk->thread.xstate->hardfpu.fp_regs[m+1];
531 if ((finsn & 0xf00f) == 0xf000)
532 llx = denormal_addd(llx, lly);
533 else
534 llx = denormal_addd(llx, lly ^ (1LL << 63));
535 tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
536 tsk->thread.xstate->hardfpu.fp_regs[n+1] = llx & 0xffffffff;
537 } else if ((fpscr & FPSCR_FPU_ERROR)
538 && (!prec && ((hx & 0x7fffffff) < 0x00800000
539 || (hy & 0x7fffffff) < 0x00800000))) {
540 /* FPU error because of denormal */
541 if ((finsn & 0xf00f) == 0xf000)
542 hx = denormal_addf(hx, hy);
543 else
544 hx = denormal_addf(hx, hy ^ 0x80000000);
545 tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
546 } else
547 return 0;
548
549 regs->pc = nextpc;
550 return 1;
551 }
552
553 return 0;
554}
555
556BUILD_TRAP_HANDLER(fpu_error)
557{
558 struct task_struct *tsk = current;
559 TRAP_HANDLER_DECL;
560
561 __unlazy_fpu(tsk, regs);
562 if (ieee_fpe_handler(regs)) {
563 tsk->thread.xstate->hardfpu.fpscr &=
564 ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
565 grab_fpu(regs);
566 restore_fpu(tsk);
567 task_thread_info(tsk)->status |= TS_USEDFPU;
568 return;
569 }
570
571 force_sig(SIGFPE);
572}