aboutsummaryrefslogtreecommitdiff
path: root/arch/nds32/math-emu/fpuemu.c
blob: 75cf1643fa78e6ede16924169cdddb49187e05ce (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2018 Andes Technology Corporation

#include <asm/bitfield.h>
#include <asm/uaccess.h>
#include <asm/sfp-machine.h>
#include <asm/fpuemu.h>
#include <asm/nds32_fpu_inst.h>

#define DPFROMREG(dp, x) (dp = (void *)((unsigned long *)fpu_reg + 2*x))
#ifdef __NDS32_EL__
#define SPFROMREG(sp, x)\
	((sp) = (void *)((unsigned long *)fpu_reg + (x^1)))
#else
#define SPFROMREG(sp, x) ((sp) = (void *)((unsigned long *)fpu_reg + x))
#endif

#define DEF3OP(name, p, f1, f2) \
void fpemu_##name##p(void *ft, void *fa, void *fb) \
{ \
	f1(fa, fa, fb); \
	f2(ft, ft, fa); \
}

#define DEF3OPNEG(name, p, f1, f2, f3) \
void fpemu_##name##p(void *ft, void *fa, void *fb) \
{ \
	f1(fa, fa, fb); \
	f2(ft, ft, fa); \
	f3(ft, ft); \
}
DEF3OP(fmadd, s, fmuls, fadds);
DEF3OP(fmsub, s, fmuls, fsubs);
DEF3OP(fmadd, d, fmuld, faddd);
DEF3OP(fmsub, d, fmuld, fsubd);
DEF3OPNEG(fnmadd, s, fmuls, fadds, fnegs);
DEF3OPNEG(fnmsub, s, fmuls, fsubs, fnegs);
DEF3OPNEG(fnmadd, d, fmuld, faddd, fnegd);
DEF3OPNEG(fnmsub, d, fmuld, fsubd, fnegd);

static const unsigned char cmptab[8] = {
	SF_CEQ,
	SF_CEQ,
	SF_CLT,
	SF_CLT,
	SF_CLT | SF_CEQ,
	SF_CLT | SF_CEQ,
	SF_CUN,
	SF_CUN
};

enum ARGTYPE {
	S1S = 1,
	S2S,
	S1D,
	CS,
	D1D,
	D2D,
	D1S,
	CD
};
union func_t {
	void (*t)(void *ft, void *fa, void *fb);
	void (*b)(void *ft, void *fa);
};
/*
 * Emulate a single FPU arithmetic instruction.
 */
static int fpu_emu(struct fpu_struct *fpu_reg, unsigned long insn)
{
	int rfmt;		/* resulting format */
	union func_t func;
	int ftype = 0;

	switch (rfmt = NDS32Insn_OPCODE_COP0(insn)) {
	case fs1_op:{
			switch (NDS32Insn_OPCODE_BIT69(insn)) {
			case fadds_op:
				func.t = fadds;
				ftype = S2S;
				break;
			case fsubs_op:
				func.t = fsubs;
				ftype = S2S;
				break;
			case fmadds_op:
				func.t = fpemu_fmadds;
				ftype = S2S;
				break;
			case fmsubs_op:
				func.t = fpemu_fmsubs;
				ftype = S2S;
				break;
			case fnmadds_op:
				func.t = fpemu_fnmadds;
				ftype = S2S;
				break;
			case fnmsubs_op:
				func.t = fpemu_fnmsubs;
				ftype = S2S;
				break;
			case fmuls_op:
				func.t = fmuls;
				ftype = S2S;
				break;
			case fdivs_op:
				func.t = fdivs;
				ftype = S2S;
				break;
			case fs1_f2op_op:
				switch (NDS32Insn_OPCODE_BIT1014(insn)) {
				case fs2d_op:
					func.b = fs2d;
					ftype = S1D;
					break;
				case fsqrts_op:
					func.b = fsqrts;
					ftype = S1S;
					break;
				default:
					return SIGILL;
				}
				break;
			default:
				return SIGILL;
			}
			break;
		}
	case fs2_op:
		switch (NDS32Insn_OPCODE_BIT69(insn)) {
		case fcmpeqs_op:
		case fcmpeqs_e_op:
		case fcmplts_op:
		case fcmplts_e_op:
		case fcmples_op:
		case fcmples_e_op:
		case fcmpuns_op:
		case fcmpuns_e_op:
			ftype = CS;
			break;
		default:
			return SIGILL;
		}
		break;
	case fd1_op:{
			switch (NDS32Insn_OPCODE_BIT69(insn)) {
			case faddd_op:
				func.t = faddd;
				ftype = D2D;
				break;
			case fsubd_op:
				func.t = fsubd;
				ftype = D2D;
				break;
			case fmaddd_op:
				func.t = fpemu_fmaddd;
				ftype = D2D;
				break;
			case fmsubd_op:
				func.t = fpemu_fmsubd;
				ftype = D2D;
				break;
			case fnmaddd_op:
				func.t = fpemu_fnmaddd;
				ftype = D2D;
				break;
			case fnmsubd_op:
				func.t = fpemu_fnmsubd;
				ftype = D2D;
				break;
			case fmuld_op:
				func.t = fmuld;
				ftype = D2D;
				break;
			case fdivd_op:
				func.t = fdivd;
				ftype = D2D;
				break;
			case fd1_f2op_op:
				switch (NDS32Insn_OPCODE_BIT1014(insn)) {
				case fd2s_op:
					func.b = fd2s;
					ftype = D1S;
					break;
				case fsqrtd_op:
					func.b = fsqrtd;
					ftype = D1D;
					break;
				default:
					return SIGILL;
				}
				break;
			default:
				return SIGILL;

			}
			break;
		}

	case fd2_op:
		switch (NDS32Insn_OPCODE_BIT69(insn)) {
		case fcmpeqd_op:
		case fcmpeqd_e_op:
		case fcmpltd_op:
		case fcmpltd_e_op:
		case fcmpled_op:
		case fcmpled_e_op:
		case fcmpund_op:
		case fcmpund_e_op:
			ftype = CD;
			break;
		default:
			return SIGILL;
		}
		break;

	default:
		return SIGILL;
	}

	switch (ftype) {
	case S1S:{
			void *ft, *fa;

			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
			SPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
			func.b(ft, fa);
			break;
		}
	case S2S:{
			void *ft, *fa, *fb;

			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
			SPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
			SPFROMREG(fb, NDS32Insn_OPCODE_Rb(insn));
			func.t(ft, fa, fb);
			break;
		}
	case S1D:{
			void *ft, *fa;

			DPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
			SPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
			func.b(ft, fa);
			break;
		}
	case CS:{
			unsigned int cmpop = NDS32Insn_OPCODE_BIT69(insn);
			void *ft, *fa, *fb;

			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
			SPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
			SPFROMREG(fb, NDS32Insn_OPCODE_Rb(insn));
			if (cmpop < 0x8) {
				cmpop = cmptab[cmpop];
				fcmps(ft, fa, fb, cmpop);
			} else
				return SIGILL;
			break;
		}
	case D1D:{
			void *ft, *fa;

			DPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
			DPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
			func.b(ft, fa);
			break;
		}
	case D2D:{
			void *ft, *fa, *fb;

			DPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
			DPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
			DPFROMREG(fb, NDS32Insn_OPCODE_Rb(insn));
			func.t(ft, fa, fb);
			break;
		}
	case D1S:{
			void *ft, *fa;

			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
			DPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
			func.b(ft, fa);
			break;
		}
	case CD:{
			unsigned int cmpop = NDS32Insn_OPCODE_BIT69(insn);
			void *ft, *fa, *fb;

			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
			DPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
			DPFROMREG(fb, NDS32Insn_OPCODE_Rb(insn));
			if (cmpop < 0x8) {
				cmpop = cmptab[cmpop];
				fcmpd(ft, fa, fb, cmpop);
			} else
				return SIGILL;
			break;
		}
	default:
		return SIGILL;
	}

	/*
	 * If an exception is required, generate a tidy SIGFPE exception.
	 */
#if IS_ENABLED(CONFIG_SUPPORT_DENORMAL_ARITHMETIC)
	if (((fpu_reg->fpcsr << 5) & fpu_reg->fpcsr & FPCSR_mskALLE_NO_UDFE) ||
	    ((fpu_reg->fpcsr & FPCSR_mskUDF) && (fpu_reg->UDF_trap)))
#else
	if ((fpu_reg->fpcsr << 5) & fpu_reg->fpcsr & FPCSR_mskALLE)
#endif
		return SIGFPE;
	return 0;
}


int do_fpuemu(struct pt_regs *regs, struct fpu_struct *fpu)
{
	unsigned long insn = 0, addr = regs->ipc;
	unsigned long emulpc, contpc;
	unsigned char *pc = (void *)&insn;
	char c;
	int i = 0, ret;

	for (i = 0; i < 4; i++) {
		if (__get_user(c, (unsigned char *)addr++))
			return SIGBUS;
		*pc++ = c;
	}

	insn = be32_to_cpu(insn);

	emulpc = regs->ipc;
	contpc = regs->ipc + 4;

	if (NDS32Insn_OPCODE(insn) != cop0_op)
		return SIGILL;
	switch (NDS32Insn_OPCODE_COP0(insn)) {
	case fs1_op:
	case fs2_op:
	case fd1_op:
	case fd2_op:
		{
			/* a real fpu computation instruction */
			ret = fpu_emu(fpu, insn);
			if (!ret)
				regs->ipc = contpc;
		}
		break;

	default:
		return SIGILL;
	}

	return ret;
}