1 /*
2 * arch/sh/math-emu/math.c
3 *
4 * Copyright (C) 2006 Takashi YOSHII <takasi-y@ops.dti.ne.jp>
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 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/types.h>
13 #include <linux/sched.h>
14 #include <linux/signal.h>
15
16 #include <asm/system.h>
17 #include <asm/uaccess.h>
18 #include <asm/processor.h>
19 #include <asm/io.h>
20
21 #include "sfp-util.h"
22 #include <math-emu/soft-fp.h>
23 #include <math-emu/single.h>
24 #include <math-emu/double.h>
25
26 #define FPUL (fregs->fpul)
27 #define FPSCR (fregs->fpscr)
28 #define FPSCR_RM (FPSCR&3)
29 #define FPSCR_DN ((FPSCR>>18)&1)
30 #define FPSCR_PR ((FPSCR>>19)&1)
31 #define FPSCR_SZ ((FPSCR>>20)&1)
32 #define FPSCR_FR ((FPSCR>>21)&1)
33 #define FPSCR_MASK 0x003fffffUL
34
35 #define BANK(n) (n^(FPSCR_FR?16:0))
36 #define FR ((unsigned long*)(fregs->fp_regs))
37 #define FR0 (FR[BANK(0)])
38 #define FRn (FR[BANK(n)])
39 #define FRm (FR[BANK(m)])
40 #define DR ((unsigned long long*)(fregs->fp_regs))
41 #define DRn (DR[BANK(n)/2])
42 #define DRm (DR[BANK(m)/2])
43
44 #define XREG(n) (n^16)
45 #define XFn (FR[BANK(XREG(n))])
46 #define XFm (FR[BANK(XREG(m))])
47 #define XDn (DR[BANK(XREG(n))/2])
48 #define XDm (DR[BANK(XREG(m))/2])
49
50 #define R0 (regs->regs[0])
51 #define Rn (regs->regs[n])
52 #define Rm (regs->regs[m])
53
54 #define WRITE(d,a) ({if(put_user(d, (typeof (d)*)a)) return -EFAULT;})
55 #define READ(d,a) ({if(get_user(d, (typeof (d)*)a)) return -EFAULT;})
56
57 #define PACK_S(r,f) FP_PACK_SP(&r,f)
58 #define UNPACK_S(f,r) FP_UNPACK_SP(f,&r)
59 #define PACK_D(r,f) \
60 {u32 t[2]; FP_PACK_DP(t,f); ((u32*)&r)[0]=t[1]; ((u32*)&r)[1]=t[0];}
61 #define UNPACK_D(f,r) \
62 {u32 t[2]; t[0]=((u32*)&r)[1]; t[1]=((u32*)&r)[0]; FP_UNPACK_DP(f,t);}
63
64 // 2 args instructions.
65 #define BOTH_PRmn(op,x) \
66 FP_DECL_EX; if(FPSCR_PR) op(D,x,DRm,DRn); else op(S,x,FRm,FRn);
67
68 #define CMP_X(SZ,R,M,N) do{ \
69 FP_DECL_##SZ(Fm); FP_DECL_##SZ(Fn); \
70 UNPACK_##SZ(Fm, M); UNPACK_##SZ(Fn, N); \
71 FP_CMP_##SZ(R, Fn, Fm, 2); }while(0)
72 #define EQ_X(SZ,R,M,N) do{ \
73 FP_DECL_##SZ(Fm); FP_DECL_##SZ(Fn); \
74 UNPACK_##SZ(Fm, M); UNPACK_##SZ(Fn, N); \
75 FP_CMP_EQ_##SZ(R, Fn, Fm); }while(0)
76 #define CMP(OP) ({ int r; BOTH_PRmn(OP##_X,r); r; })
77
78 static int
fcmp_gt(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)79 fcmp_gt(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
80 {
81 if (CMP(CMP) > 0)
82 regs->sr |= 1;
83 else
84 regs->sr &= ~1;
85
86 return 0;
87 }
88
89 static int
fcmp_eq(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)90 fcmp_eq(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
91 {
92 if (CMP(CMP /*EQ*/) == 0)
93 regs->sr |= 1;
94 else
95 regs->sr &= ~1;
96 return 0;
97 }
98
99 #define ARITH_X(SZ,OP,M,N) do{ \
100 FP_DECL_##SZ(Fm); FP_DECL_##SZ(Fn); FP_DECL_##SZ(Fr); \
101 UNPACK_##SZ(Fm, M); UNPACK_##SZ(Fn, N); \
102 FP_##OP##_##SZ(Fr, Fn, Fm); \
103 PACK_##SZ(N, Fr); }while(0)
104
105 static int
fadd(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)106 fadd(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
107 {
108 BOTH_PRmn(ARITH_X, ADD);
109 return 0;
110 }
111
112 static int
fsub(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)113 fsub(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
114 {
115 BOTH_PRmn(ARITH_X, SUB);
116 return 0;
117 }
118
119 static int
fmul(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)120 fmul(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
121 {
122 BOTH_PRmn(ARITH_X, MUL);
123 return 0;
124 }
125
126 static int
fdiv(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)127 fdiv(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
128 {
129 BOTH_PRmn(ARITH_X, DIV);
130 return 0;
131 }
132
133 static int
fmac(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)134 fmac(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
135 {
136 FP_DECL_EX;
137 FP_DECL_S(Fr);
138 FP_DECL_S(Ft);
139 FP_DECL_S(F0);
140 FP_DECL_S(Fm);
141 FP_DECL_S(Fn);
142 UNPACK_S(F0, FR0);
143 UNPACK_S(Fm, FRm);
144 UNPACK_S(Fn, FRn);
145 FP_MUL_S(Ft, Fm, F0);
146 FP_ADD_S(Fr, Fn, Ft);
147 PACK_S(FRn, Fr);
148 return 0;
149 }
150
151 // to process fmov's extension (odd n for DR access XD).
152 #define FMOV_EXT(x) if(x&1) x+=16-1
153
154 static int
fmov_idx_reg(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)155 fmov_idx_reg(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
156 int n)
157 {
158 if (FPSCR_SZ) {
159 FMOV_EXT(n);
160 READ(FRn, Rm + R0 + 4);
161 n++;
162 READ(FRn, Rm + R0);
163 } else {
164 READ(FRn, Rm + R0);
165 }
166
167 return 0;
168 }
169
170 static int
fmov_mem_reg(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)171 fmov_mem_reg(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
172 int n)
173 {
174 if (FPSCR_SZ) {
175 FMOV_EXT(n);
176 READ(FRn, Rm + 4);
177 n++;
178 READ(FRn, Rm);
179 } else {
180 READ(FRn, Rm);
181 }
182
183 return 0;
184 }
185
186 static int
fmov_inc_reg(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)187 fmov_inc_reg(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
188 int n)
189 {
190 if (FPSCR_SZ) {
191 FMOV_EXT(n);
192 READ(FRn, Rm + 4);
193 n++;
194 READ(FRn, Rm);
195 Rm += 8;
196 } else {
197 READ(FRn, Rm);
198 Rm += 4;
199 }
200
201 return 0;
202 }
203
204 static int
fmov_reg_idx(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)205 fmov_reg_idx(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
206 int n)
207 {
208 if (FPSCR_SZ) {
209 FMOV_EXT(m);
210 WRITE(FRm, Rn + R0 + 4);
211 m++;
212 WRITE(FRm, Rn + R0);
213 } else {
214 WRITE(FRm, Rn + R0);
215 }
216
217 return 0;
218 }
219
220 static int
fmov_reg_mem(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)221 fmov_reg_mem(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
222 int n)
223 {
224 if (FPSCR_SZ) {
225 FMOV_EXT(m);
226 WRITE(FRm, Rn + 4);
227 m++;
228 WRITE(FRm, Rn);
229 } else {
230 WRITE(FRm, Rn);
231 }
232
233 return 0;
234 }
235
236 static int
fmov_reg_dec(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)237 fmov_reg_dec(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
238 int n)
239 {
240 if (FPSCR_SZ) {
241 FMOV_EXT(m);
242 Rn -= 8;
243 WRITE(FRm, Rn + 4);
244 m++;
245 WRITE(FRm, Rn);
246 } else {
247 Rn -= 4;
248 WRITE(FRm, Rn);
249 }
250
251 return 0;
252 }
253
254 static int
fmov_reg_reg(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)255 fmov_reg_reg(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
256 int n)
257 {
258 if (FPSCR_SZ) {
259 FMOV_EXT(m);
260 FMOV_EXT(n);
261 DRn = DRm;
262 } else {
263 FRn = FRm;
264 }
265
266 return 0;
267 }
268
269 static int
fnop_mn(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int m,int n)270 fnop_mn(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
271 {
272 return -EINVAL;
273 }
274
275 // 1 arg instructions.
276 #define NOTYETn(i) static int i(struct sh_fpu_soft_struct *fregs, int n) \
277 { printk( #i " not yet done.\n"); return 0; }
278
279 NOTYETn(ftrv)
NOTYETn(fsqrt)280 NOTYETn(fsqrt)
281 NOTYETn(fipr)
282 NOTYETn(fsca)
283 NOTYETn(fsrra)
284
285 #define EMU_FLOAT_X(SZ,N) do { \
286 FP_DECL_##SZ(Fn); \
287 FP_FROM_INT_##SZ(Fn, FPUL, 32, int); \
288 PACK_##SZ(N, Fn); }while(0)
289 static int ffloat(struct sh_fpu_soft_struct *fregs, int n)
290 {
291 FP_DECL_EX;
292
293 if (FPSCR_PR)
294 EMU_FLOAT_X(D, DRn);
295 else
296 EMU_FLOAT_X(S, FRn);
297
298 return 0;
299 }
300
301 #define EMU_FTRC_X(SZ,N) do { \
302 FP_DECL_##SZ(Fn); \
303 UNPACK_##SZ(Fn, N); \
304 FP_TO_INT_##SZ(FPUL, Fn, 32, 1); }while(0)
ftrc(struct sh_fpu_soft_struct * fregs,int n)305 static int ftrc(struct sh_fpu_soft_struct *fregs, int n)
306 {
307 FP_DECL_EX;
308
309 if (FPSCR_PR)
310 EMU_FTRC_X(D, DRn);
311 else
312 EMU_FTRC_X(S, FRn);
313
314 return 0;
315 }
316
fcnvsd(struct sh_fpu_soft_struct * fregs,int n)317 static int fcnvsd(struct sh_fpu_soft_struct *fregs, int n)
318 {
319 FP_DECL_EX;
320 FP_DECL_S(Fn);
321 FP_DECL_D(Fr);
322 UNPACK_S(Fn, FPUL);
323 FP_CONV(D, S, 2, 1, Fr, Fn);
324 PACK_D(DRn, Fr);
325 return 0;
326 }
327
fcnvds(struct sh_fpu_soft_struct * fregs,int n)328 static int fcnvds(struct sh_fpu_soft_struct *fregs, int n)
329 {
330 FP_DECL_EX;
331 FP_DECL_D(Fn);
332 FP_DECL_S(Fr);
333 UNPACK_D(Fn, DRn);
334 FP_CONV(S, D, 1, 2, Fr, Fn);
335 PACK_S(FPUL, Fr);
336 return 0;
337 }
338
fxchg(struct sh_fpu_soft_struct * fregs,int flag)339 static int fxchg(struct sh_fpu_soft_struct *fregs, int flag)
340 {
341 FPSCR ^= flag;
342 return 0;
343 }
344
fsts(struct sh_fpu_soft_struct * fregs,int n)345 static int fsts(struct sh_fpu_soft_struct *fregs, int n)
346 {
347 FRn = FPUL;
348 return 0;
349 }
350
flds(struct sh_fpu_soft_struct * fregs,int n)351 static int flds(struct sh_fpu_soft_struct *fregs, int n)
352 {
353 FPUL = FRn;
354 return 0;
355 }
356
fneg(struct sh_fpu_soft_struct * fregs,int n)357 static int fneg(struct sh_fpu_soft_struct *fregs, int n)
358 {
359 FRn ^= (1 << (_FP_W_TYPE_SIZE - 1));
360 return 0;
361 }
362
fabs(struct sh_fpu_soft_struct * fregs,int n)363 static int fabs(struct sh_fpu_soft_struct *fregs, int n)
364 {
365 FRn &= ~(1 << (_FP_W_TYPE_SIZE - 1));
366 return 0;
367 }
368
fld0(struct sh_fpu_soft_struct * fregs,int n)369 static int fld0(struct sh_fpu_soft_struct *fregs, int n)
370 {
371 FRn = 0;
372 return 0;
373 }
374
fld1(struct sh_fpu_soft_struct * fregs,int n)375 static int fld1(struct sh_fpu_soft_struct *fregs, int n)
376 {
377 FRn = (_FP_EXPBIAS_S << (_FP_FRACBITS_S - 1));
378 return 0;
379 }
380
fnop_n(struct sh_fpu_soft_struct * fregs,int n)381 static int fnop_n(struct sh_fpu_soft_struct *fregs, int n)
382 {
383 return -EINVAL;
384 }
385
386 /// Instruction decoders.
387
388 static int id_fxfd(struct sh_fpu_soft_struct *, int);
389 static int id_fnxd(struct sh_fpu_soft_struct *, struct pt_regs *, int, int);
390
391 static int (*fnxd[])(struct sh_fpu_soft_struct *, int) = {
392 fsts, flds, ffloat, ftrc, fneg, fabs, fsqrt, fsrra,
393 fld0, fld1, fcnvsd, fcnvds, fnop_n, fnop_n, fipr, id_fxfd
394 };
395
396 static int (*fnmx[])(struct sh_fpu_soft_struct *, struct pt_regs *, int, int) = {
397 fadd, fsub, fmul, fdiv, fcmp_eq, fcmp_gt, fmov_idx_reg, fmov_reg_idx,
398 fmov_mem_reg, fmov_inc_reg, fmov_reg_mem, fmov_reg_dec,
399 fmov_reg_reg, id_fnxd, fmac, fnop_mn};
400
id_fxfd(struct sh_fpu_soft_struct * fregs,int x)401 static int id_fxfd(struct sh_fpu_soft_struct *fregs, int x)
402 {
403 const int flag[] = { FPSCR_SZ, FPSCR_PR, FPSCR_FR, 0 };
404 switch (x & 3) {
405 case 3:
406 fxchg(fregs, flag[x >> 2]);
407 break;
408 case 1:
409 ftrv(fregs, x - 1);
410 break;
411 default:
412 fsca(fregs, x);
413 }
414 return 0;
415 }
416
417 static int
id_fnxd(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,int x,int n)418 id_fnxd(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int x, int n)
419 {
420 return (fnxd[x])(fregs, n);
421 }
422
423 static int
id_fnmx(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,u16 code)424 id_fnmx(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, u16 code)
425 {
426 int n = (code >> 8) & 0xf, m = (code >> 4) & 0xf, x = code & 0xf;
427 return (fnmx[x])(fregs, regs, m, n);
428 }
429
430 static int
id_sys(struct sh_fpu_soft_struct * fregs,struct pt_regs * regs,u16 code)431 id_sys(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, u16 code)
432 {
433 int n = ((code >> 8) & 0xf);
434 unsigned long *reg = (code & 0x0010) ? &FPUL : &FPSCR;
435
436 switch (code & 0xf0ff) {
437 case 0x005a:
438 case 0x006a:
439 Rn = *reg;
440 break;
441 case 0x405a:
442 case 0x406a:
443 *reg = Rn;
444 break;
445 case 0x4052:
446 case 0x4062:
447 Rn -= 4;
448 WRITE(*reg, Rn);
449 break;
450 case 0x4056:
451 case 0x4066:
452 READ(*reg, Rn);
453 Rn += 4;
454 break;
455 default:
456 return -EINVAL;
457 }
458
459 return 0;
460 }
461
fpu_emulate(u16 code,struct sh_fpu_soft_struct * fregs,struct pt_regs * regs)462 static int fpu_emulate(u16 code, struct sh_fpu_soft_struct *fregs, struct pt_regs *regs)
463 {
464 if ((code & 0xf000) == 0xf000)
465 return id_fnmx(fregs, regs, code);
466 else
467 return id_sys(fregs, regs, code);
468 }
469
470 /**
471 * denormal_to_double - Given denormalized float number,
472 * store double float
473 *
474 * @fpu: Pointer to sh_fpu_hard structure
475 * @n: Index to FP register
476 */
denormal_to_double(struct sh_fpu_hard_struct * fpu,int n)477 static void denormal_to_double(struct sh_fpu_hard_struct *fpu, int n)
478 {
479 unsigned long du, dl;
480 unsigned long x = fpu->fpul;
481 int exp = 1023 - 126;
482
483 if (x != 0 && (x & 0x7f800000) == 0) {
484 du = (x & 0x80000000);
485 while ((x & 0x00800000) == 0) {
486 x <<= 1;
487 exp--;
488 }
489 x &= 0x007fffff;
490 du |= (exp << 20) | (x >> 3);
491 dl = x << 29;
492
493 fpu->fp_regs[n] = du;
494 fpu->fp_regs[n+1] = dl;
495 }
496 }
497
498 /**
499 * ieee_fpe_handler - Handle denormalized number exception
500 *
501 * @regs: Pointer to register structure
502 *
503 * Returns 1 when it's handled (should not cause exception).
504 */
ieee_fpe_handler(struct pt_regs * regs)505 static int ieee_fpe_handler(struct pt_regs *regs)
506 {
507 unsigned short insn = *(unsigned short *)regs->pc;
508 unsigned short finsn;
509 unsigned long nextpc;
510 siginfo_t info;
511 int nib[4] = {
512 (insn >> 12) & 0xf,
513 (insn >> 8) & 0xf,
514 (insn >> 4) & 0xf,
515 insn & 0xf};
516
517 if (nib[0] == 0xb ||
518 (nib[0] == 0x4 && nib[2] == 0x0 && nib[3] == 0xb)) /* bsr & jsr */
519 regs->pr = regs->pc + 4;
520
521 if (nib[0] == 0xa || nib[0] == 0xb) { /* bra & bsr */
522 nextpc = regs->pc + 4 + ((short) ((insn & 0xfff) << 4) >> 3);
523 finsn = *(unsigned short *) (regs->pc + 2);
524 } else if (nib[0] == 0x8 && nib[1] == 0xd) { /* bt/s */
525 if (regs->sr & 1)
526 nextpc = regs->pc + 4 + ((char) (insn & 0xff) << 1);
527 else
528 nextpc = regs->pc + 4;
529 finsn = *(unsigned short *) (regs->pc + 2);
530 } else if (nib[0] == 0x8 && nib[1] == 0xf) { /* bf/s */
531 if (regs->sr & 1)
532 nextpc = regs->pc + 4;
533 else
534 nextpc = regs->pc + 4 + ((char) (insn & 0xff) << 1);
535 finsn = *(unsigned short *) (regs->pc + 2);
536 } else if (nib[0] == 0x4 && nib[3] == 0xb &&
537 (nib[2] == 0x0 || nib[2] == 0x2)) { /* jmp & jsr */
538 nextpc = regs->regs[nib[1]];
539 finsn = *(unsigned short *) (regs->pc + 2);
540 } else if (nib[0] == 0x0 && nib[3] == 0x3 &&
541 (nib[2] == 0x0 || nib[2] == 0x2)) { /* braf & bsrf */
542 nextpc = regs->pc + 4 + regs->regs[nib[1]];
543 finsn = *(unsigned short *) (regs->pc + 2);
544 } else if (insn == 0x000b) { /* rts */
545 nextpc = regs->pr;
546 finsn = *(unsigned short *) (regs->pc + 2);
547 } else {
548 nextpc = regs->pc + 2;
549 finsn = insn;
550 }
551
552 if ((finsn & 0xf1ff) == 0xf0ad) { /* fcnvsd */
553 struct task_struct *tsk = current;
554
555 if ((tsk->thread.fpu.hard.fpscr & (1 << 17))) {
556 /* FPU error */
557 denormal_to_double (&tsk->thread.fpu.hard,
558 (finsn >> 8) & 0xf);
559 tsk->thread.fpu.hard.fpscr &=
560 ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
561 set_tsk_thread_flag(tsk, TIF_USEDFPU);
562 } else {
563 info.si_signo = SIGFPE;
564 info.si_errno = 0;
565 info.si_code = FPE_FLTINV;
566 info.si_addr = (void __user *)regs->pc;
567 force_sig_info(SIGFPE, &info, tsk);
568 }
569
570 regs->pc = nextpc;
571 return 1;
572 }
573
574 return 0;
575 }
576
do_fpu_error(unsigned long r4,unsigned long r5,unsigned long r6,unsigned long r7,struct pt_regs regs)577 asmlinkage void do_fpu_error(unsigned long r4, unsigned long r5,
578 unsigned long r6, unsigned long r7,
579 struct pt_regs regs)
580 {
581 struct task_struct *tsk = current;
582 siginfo_t info;
583
584 if (ieee_fpe_handler (®s))
585 return;
586
587 regs.pc += 2;
588 info.si_signo = SIGFPE;
589 info.si_errno = 0;
590 info.si_code = FPE_FLTINV;
591 info.si_addr = (void __user *)regs.pc;
592 force_sig_info(SIGFPE, &info, tsk);
593 }
594
595 /**
596 * fpu_init - Initialize FPU registers
597 * @fpu: Pointer to software emulated FPU registers.
598 */
fpu_init(struct sh_fpu_soft_struct * fpu)599 static void fpu_init(struct sh_fpu_soft_struct *fpu)
600 {
601 int i;
602
603 fpu->fpscr = FPSCR_INIT;
604 fpu->fpul = 0;
605
606 for (i = 0; i < 16; i++) {
607 fpu->fp_regs[i] = 0;
608 fpu->xfp_regs[i]= 0;
609 }
610 }
611
612 /**
613 * do_fpu_inst - Handle reserved instructions for FPU emulation
614 * @inst: instruction code.
615 * @regs: registers on stack.
616 */
do_fpu_inst(unsigned short inst,struct pt_regs * regs)617 int do_fpu_inst(unsigned short inst, struct pt_regs *regs)
618 {
619 struct task_struct *tsk = current;
620 struct sh_fpu_soft_struct *fpu = &(tsk->thread.fpu.soft);
621
622 if (!test_tsk_thread_flag(tsk, TIF_USEDFPU)) {
623 /* initialize once. */
624 fpu_init(fpu);
625 set_tsk_thread_flag(tsk, TIF_USEDFPU);
626 }
627
628 return fpu_emulate(inst, fpu, regs);
629 }
630