xref: /linux/arch/powerpc/math-emu/math.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  * Copyright (C) 1999  Eddie C. Dost  (ecd@atecom.com)
3  */
4 
5 #include <linux/config.h>
6 #include <linux/types.h>
7 #include <linux/sched.h>
8 
9 #include <asm/uaccess.h>
10 #include <asm/reg.h>
11 
12 #include "sfp-machine.h"
13 #include "double.h"
14 
15 #define FLOATFUNC(x)	extern int x(void *, void *, void *, void *)
16 
17 FLOATFUNC(fadd);
18 FLOATFUNC(fadds);
19 FLOATFUNC(fdiv);
20 FLOATFUNC(fdivs);
21 FLOATFUNC(fmul);
22 FLOATFUNC(fmuls);
23 FLOATFUNC(fsub);
24 FLOATFUNC(fsubs);
25 
26 FLOATFUNC(fmadd);
27 FLOATFUNC(fmadds);
28 FLOATFUNC(fmsub);
29 FLOATFUNC(fmsubs);
30 FLOATFUNC(fnmadd);
31 FLOATFUNC(fnmadds);
32 FLOATFUNC(fnmsub);
33 FLOATFUNC(fnmsubs);
34 
35 FLOATFUNC(fctiw);
36 FLOATFUNC(fctiwz);
37 FLOATFUNC(frsp);
38 
39 FLOATFUNC(fcmpo);
40 FLOATFUNC(fcmpu);
41 
42 FLOATFUNC(mcrfs);
43 FLOATFUNC(mffs);
44 FLOATFUNC(mtfsb0);
45 FLOATFUNC(mtfsb1);
46 FLOATFUNC(mtfsf);
47 FLOATFUNC(mtfsfi);
48 
49 FLOATFUNC(lfd);
50 FLOATFUNC(lfs);
51 
52 FLOATFUNC(stfd);
53 FLOATFUNC(stfs);
54 FLOATFUNC(stfiwx);
55 
56 FLOATFUNC(fabs);
57 FLOATFUNC(fmr);
58 FLOATFUNC(fnabs);
59 FLOATFUNC(fneg);
60 
61 /* Optional */
62 FLOATFUNC(fres);
63 FLOATFUNC(frsqrte);
64 FLOATFUNC(fsel);
65 FLOATFUNC(fsqrt);
66 FLOATFUNC(fsqrts);
67 
68 
69 #define OP31		0x1f		/*   31 */
70 #define LFS		0x30		/*   48 */
71 #define LFSU		0x31		/*   49 */
72 #define LFD		0x32		/*   50 */
73 #define LFDU		0x33		/*   51 */
74 #define STFS		0x34		/*   52 */
75 #define STFSU		0x35		/*   53 */
76 #define STFD		0x36		/*   54 */
77 #define STFDU		0x37		/*   55 */
78 #define OP59		0x3b		/*   59 */
79 #define OP63		0x3f		/*   63 */
80 
81 /* Opcode 31: */
82 /* X-Form: */
83 #define LFSX		0x217		/*  535 */
84 #define LFSUX		0x237		/*  567 */
85 #define LFDX		0x257		/*  599 */
86 #define LFDUX		0x277		/*  631 */
87 #define STFSX		0x297		/*  663 */
88 #define STFSUX		0x2b7		/*  695 */
89 #define STFDX		0x2d7		/*  727 */
90 #define STFDUX		0x2f7		/*  759 */
91 #define STFIWX		0x3d7		/*  983 */
92 
93 /* Opcode 59: */
94 /* A-Form: */
95 #define FDIVS		0x012		/*   18 */
96 #define FSUBS		0x014		/*   20 */
97 #define FADDS		0x015		/*   21 */
98 #define FSQRTS		0x016		/*   22 */
99 #define FRES		0x018		/*   24 */
100 #define FMULS		0x019		/*   25 */
101 #define FMSUBS		0x01c		/*   28 */
102 #define FMADDS		0x01d		/*   29 */
103 #define FNMSUBS		0x01e		/*   30 */
104 #define FNMADDS		0x01f		/*   31 */
105 
106 /* Opcode 63: */
107 /* A-Form: */
108 #define FDIV		0x012		/*   18 */
109 #define FSUB		0x014		/*   20 */
110 #define FADD		0x015		/*   21 */
111 #define FSQRT		0x016		/*   22 */
112 #define FSEL		0x017		/*   23 */
113 #define FMUL		0x019		/*   25 */
114 #define FRSQRTE		0x01a		/*   26 */
115 #define FMSUB		0x01c		/*   28 */
116 #define FMADD		0x01d		/*   29 */
117 #define FNMSUB		0x01e		/*   30 */
118 #define FNMADD		0x01f		/*   31 */
119 
120 /* X-Form: */
121 #define FCMPU		0x000		/*    0	*/
122 #define FRSP		0x00c		/*   12 */
123 #define FCTIW		0x00e		/*   14 */
124 #define FCTIWZ		0x00f		/*   15 */
125 #define FCMPO		0x020		/*   32 */
126 #define MTFSB1		0x026		/*   38 */
127 #define FNEG		0x028		/*   40 */
128 #define MCRFS		0x040		/*   64 */
129 #define MTFSB0		0x046		/*   70 */
130 #define FMR		0x048		/*   72 */
131 #define MTFSFI		0x086		/*  134 */
132 #define FNABS		0x088		/*  136 */
133 #define FABS		0x108		/*  264 */
134 #define MFFS		0x247		/*  583 */
135 #define MTFSF		0x2c7		/*  711 */
136 
137 
138 #define AB	2
139 #define AC	3
140 #define ABC	4
141 #define D	5
142 #define DU	6
143 #define X	7
144 #define XA	8
145 #define XB	9
146 #define XCR	11
147 #define XCRB	12
148 #define XCRI	13
149 #define XCRL	16
150 #define XE	14
151 #define XEU	15
152 #define XFLB	10
153 
154 #ifdef CONFIG_MATH_EMULATION
155 static int
156 record_exception(struct pt_regs *regs, int eflag)
157 {
158 	u32 fpscr;
159 
160 	fpscr = __FPU_FPSCR;
161 
162 	if (eflag) {
163 		fpscr |= FPSCR_FX;
164 		if (eflag & EFLAG_OVERFLOW)
165 			fpscr |= FPSCR_OX;
166 		if (eflag & EFLAG_UNDERFLOW)
167 			fpscr |= FPSCR_UX;
168 		if (eflag & EFLAG_DIVZERO)
169 			fpscr |= FPSCR_ZX;
170 		if (eflag & EFLAG_INEXACT)
171 			fpscr |= FPSCR_XX;
172 		if (eflag & EFLAG_VXSNAN)
173 			fpscr |= FPSCR_VXSNAN;
174 		if (eflag & EFLAG_VXISI)
175 			fpscr |= FPSCR_VXISI;
176 		if (eflag & EFLAG_VXIDI)
177 			fpscr |= FPSCR_VXIDI;
178 		if (eflag & EFLAG_VXZDZ)
179 			fpscr |= FPSCR_VXZDZ;
180 		if (eflag & EFLAG_VXIMZ)
181 			fpscr |= FPSCR_VXIMZ;
182 		if (eflag & EFLAG_VXVC)
183 			fpscr |= FPSCR_VXVC;
184 		if (eflag & EFLAG_VXSOFT)
185 			fpscr |= FPSCR_VXSOFT;
186 		if (eflag & EFLAG_VXSQRT)
187 			fpscr |= FPSCR_VXSQRT;
188 		if (eflag & EFLAG_VXCVI)
189 			fpscr |= FPSCR_VXCVI;
190 	}
191 
192 	fpscr &= ~(FPSCR_VX);
193 	if (fpscr & (FPSCR_VXSNAN | FPSCR_VXISI | FPSCR_VXIDI |
194 		     FPSCR_VXZDZ | FPSCR_VXIMZ | FPSCR_VXVC |
195 		     FPSCR_VXSOFT | FPSCR_VXSQRT | FPSCR_VXCVI))
196 		fpscr |= FPSCR_VX;
197 
198 	fpscr &= ~(FPSCR_FEX);
199 	if (((fpscr & FPSCR_VX) && (fpscr & FPSCR_VE)) ||
200 	    ((fpscr & FPSCR_OX) && (fpscr & FPSCR_OE)) ||
201 	    ((fpscr & FPSCR_UX) && (fpscr & FPSCR_UE)) ||
202 	    ((fpscr & FPSCR_ZX) && (fpscr & FPSCR_ZE)) ||
203 	    ((fpscr & FPSCR_XX) && (fpscr & FPSCR_XE)))
204 		fpscr |= FPSCR_FEX;
205 
206 	__FPU_FPSCR = fpscr;
207 
208 	return (fpscr & FPSCR_FEX) ? 1 : 0;
209 }
210 #endif /* CONFIG_MATH_EMULATION */
211 
212 int
213 do_mathemu(struct pt_regs *regs)
214 {
215 	void *op0 = 0, *op1 = 0, *op2 = 0, *op3 = 0;
216 	unsigned long pc = regs->nip;
217 	signed short sdisp;
218 	u32 insn = 0;
219 	int idx = 0;
220 #ifdef CONFIG_MATH_EMULATION
221 	int (*func)(void *, void *, void *, void *);
222 	int type = 0;
223 	int eflag, trap;
224 #endif
225 
226 	if (get_user(insn, (u32 *)pc))
227 		return -EFAULT;
228 
229 #ifndef CONFIG_MATH_EMULATION
230 	switch (insn >> 26) {
231 	case LFD:
232 		idx = (insn >> 16) & 0x1f;
233 		sdisp = (insn & 0xffff);
234 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
235 		op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
236 		lfd(op0, op1, op2, op3);
237 		break;
238 	case LFDU:
239 		idx = (insn >> 16) & 0x1f;
240 		sdisp = (insn & 0xffff);
241 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
242 		op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
243 		lfd(op0, op1, op2, op3);
244 		regs->gpr[idx] = (unsigned long)op1;
245 		break;
246 	case STFD:
247 		idx = (insn >> 16) & 0x1f;
248 		sdisp = (insn & 0xffff);
249 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
250 		op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
251 		stfd(op0, op1, op2, op3);
252 		break;
253 	case STFDU:
254 		idx = (insn >> 16) & 0x1f;
255 		sdisp = (insn & 0xffff);
256 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
257 		op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
258 		stfd(op0, op1, op2, op3);
259 		regs->gpr[idx] = (unsigned long)op1;
260 		break;
261 	case OP63:
262 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
263 		op1 = (void *)&current->thread.fpr[(insn >> 11) & 0x1f];
264 		fmr(op0, op1, op2, op3);
265 		break;
266 	default:
267 		goto illegal;
268 	}
269 #else /* CONFIG_MATH_EMULATION */
270 	switch (insn >> 26) {
271 	case LFS:	func = lfs;	type = D;	break;
272 	case LFSU:	func = lfs;	type = DU;	break;
273 	case LFD:	func = lfd;	type = D;	break;
274 	case LFDU:	func = lfd;	type = DU;	break;
275 	case STFS:	func = stfs;	type = D;	break;
276 	case STFSU:	func = stfs;	type = DU;	break;
277 	case STFD:	func = stfd;	type = D;	break;
278 	case STFDU:	func = stfd;	type = DU;	break;
279 
280 	case OP31:
281 		switch ((insn >> 1) & 0x3ff) {
282 		case LFSX:	func = lfs;	type = XE;	break;
283 		case LFSUX:	func = lfs;	type = XEU;	break;
284 		case LFDX:	func = lfd;	type = XE;	break;
285 		case LFDUX:	func = lfd;	type = XEU;	break;
286 		case STFSX:	func = stfs;	type = XE;	break;
287 		case STFSUX:	func = stfs;	type = XEU;	break;
288 		case STFDX:	func = stfd;	type = XE;	break;
289 		case STFDUX:	func = stfd;	type = XEU;	break;
290 		case STFIWX:	func = stfiwx;	type = XE;	break;
291 		default:
292 			goto illegal;
293 		}
294 		break;
295 
296 	case OP59:
297 		switch ((insn >> 1) & 0x1f) {
298 		case FDIVS:	func = fdivs;	type = AB;	break;
299 		case FSUBS:	func = fsubs;	type = AB;	break;
300 		case FADDS:	func = fadds;	type = AB;	break;
301 		case FSQRTS:	func = fsqrts;	type = AB;	break;
302 		case FRES:	func = fres;	type = AB;	break;
303 		case FMULS:	func = fmuls;	type = AC;	break;
304 		case FMSUBS:	func = fmsubs;	type = ABC;	break;
305 		case FMADDS:	func = fmadds;	type = ABC;	break;
306 		case FNMSUBS:	func = fnmsubs;	type = ABC;	break;
307 		case FNMADDS:	func = fnmadds;	type = ABC;	break;
308 		default:
309 			goto illegal;
310 		}
311 		break;
312 
313 	case OP63:
314 		if (insn & 0x20) {
315 			switch ((insn >> 1) & 0x1f) {
316 			case FDIV:	func = fdiv;	type = AB;	break;
317 			case FSUB:	func = fsub;	type = AB;	break;
318 			case FADD:	func = fadd;	type = AB;	break;
319 			case FSQRT:	func = fsqrt;	type = AB;	break;
320 			case FSEL:	func = fsel;	type = ABC;	break;
321 			case FMUL:	func = fmul;	type = AC;	break;
322 			case FRSQRTE:	func = frsqrte;	type = AB;	break;
323 			case FMSUB:	func = fmsub;	type = ABC;	break;
324 			case FMADD:	func = fmadd;	type = ABC;	break;
325 			case FNMSUB:	func = fnmsub;	type = ABC;	break;
326 			case FNMADD:	func = fnmadd;	type = ABC;	break;
327 			default:
328 				goto illegal;
329 			}
330 			break;
331 		}
332 
333 		switch ((insn >> 1) & 0x3ff) {
334 		case FCMPU:	func = fcmpu;	type = XCR;	break;
335 		case FRSP:	func = frsp;	type = XB;	break;
336 		case FCTIW:	func = fctiw;	type = XB;	break;
337 		case FCTIWZ:	func = fctiwz;	type = XB;	break;
338 		case FCMPO:	func = fcmpo;	type = XCR;	break;
339 		case MTFSB1:	func = mtfsb1;	type = XCRB;	break;
340 		case FNEG:	func = fneg;	type = XB;	break;
341 		case MCRFS:	func = mcrfs;	type = XCRL;	break;
342 		case MTFSB0:	func = mtfsb0;	type = XCRB;	break;
343 		case FMR:	func = fmr;	type = XB;	break;
344 		case MTFSFI:	func = mtfsfi;	type = XCRI;	break;
345 		case FNABS:	func = fnabs;	type = XB;	break;
346 		case FABS:	func = fabs;	type = XB;	break;
347 		case MFFS:	func = mffs;	type = X;	break;
348 		case MTFSF:	func = mtfsf;	type = XFLB;	break;
349 		default:
350 			goto illegal;
351 		}
352 		break;
353 
354 	default:
355 		goto illegal;
356 	}
357 
358 	switch (type) {
359 	case AB:
360 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
361 		op1 = (void *)&current->thread.fpr[(insn >> 16) & 0x1f];
362 		op2 = (void *)&current->thread.fpr[(insn >> 11) & 0x1f];
363 		break;
364 
365 	case AC:
366 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
367 		op1 = (void *)&current->thread.fpr[(insn >> 16) & 0x1f];
368 		op2 = (void *)&current->thread.fpr[(insn >>  6) & 0x1f];
369 		break;
370 
371 	case ABC:
372 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
373 		op1 = (void *)&current->thread.fpr[(insn >> 16) & 0x1f];
374 		op2 = (void *)&current->thread.fpr[(insn >> 11) & 0x1f];
375 		op3 = (void *)&current->thread.fpr[(insn >>  6) & 0x1f];
376 		break;
377 
378 	case D:
379 		idx = (insn >> 16) & 0x1f;
380 		sdisp = (insn & 0xffff);
381 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
382 		op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
383 		break;
384 
385 	case DU:
386 		idx = (insn >> 16) & 0x1f;
387 		if (!idx)
388 			goto illegal;
389 
390 		sdisp = (insn & 0xffff);
391 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
392 		op1 = (void *)(regs->gpr[idx] + sdisp);
393 		break;
394 
395 	case X:
396 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
397 		break;
398 
399 	case XA:
400 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
401 		op1 = (void *)&current->thread.fpr[(insn >> 16) & 0x1f];
402 		break;
403 
404 	case XB:
405 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
406 		op1 = (void *)&current->thread.fpr[(insn >> 11) & 0x1f];
407 		break;
408 
409 	case XE:
410 		idx = (insn >> 16) & 0x1f;
411 		if (!idx)
412 			goto illegal;
413 
414 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
415 		op1 = (void *)(regs->gpr[idx] + regs->gpr[(insn >> 11) & 0x1f]);
416 		break;
417 
418 	case XEU:
419 		idx = (insn >> 16) & 0x1f;
420 		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
421 		op1 = (void *)((idx ? regs->gpr[idx] : 0)
422 				+ regs->gpr[(insn >> 11) & 0x1f]);
423 		break;
424 
425 	case XCR:
426 		op0 = (void *)&regs->ccr;
427 		op1 = (void *)((insn >> 23) & 0x7);
428 		op2 = (void *)&current->thread.fpr[(insn >> 16) & 0x1f];
429 		op3 = (void *)&current->thread.fpr[(insn >> 11) & 0x1f];
430 		break;
431 
432 	case XCRL:
433 		op0 = (void *)&regs->ccr;
434 		op1 = (void *)((insn >> 23) & 0x7);
435 		op2 = (void *)((insn >> 18) & 0x7);
436 		break;
437 
438 	case XCRB:
439 		op0 = (void *)((insn >> 21) & 0x1f);
440 		break;
441 
442 	case XCRI:
443 		op0 = (void *)((insn >> 23) & 0x7);
444 		op1 = (void *)((insn >> 12) & 0xf);
445 		break;
446 
447 	case XFLB:
448 		op0 = (void *)((insn >> 17) & 0xff);
449 		op1 = (void *)&current->thread.fpr[(insn >> 11) & 0x1f];
450 		break;
451 
452 	default:
453 		goto illegal;
454 	}
455 
456 	eflag = func(op0, op1, op2, op3);
457 
458 	if (insn & 1) {
459 		regs->ccr &= ~(0x0f000000);
460 		regs->ccr |= (__FPU_FPSCR >> 4) & 0x0f000000;
461 	}
462 
463 	trap = record_exception(regs, eflag);
464 	if (trap)
465 		return 1;
466 
467 	switch (type) {
468 	case DU:
469 	case XEU:
470 		regs->gpr[idx] = (unsigned long)op1;
471 		break;
472 
473 	default:
474 		break;
475 	}
476 #endif /* CONFIG_MATH_EMULATION */
477 
478 	regs->nip += 4;
479 	return 0;
480 
481 illegal:
482 	return -ENOSYS;
483 }
484