1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3     NetWinder Floating Point Emulator
4     (c) Rebel.com, 1998-1999
5     (c) Philip Blundell, 1998, 2001
6 
7     Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
8 
9 */
10 
11 #include "fpa11.h"
12 #include "softfloat.h"
13 #include "fpopcode.h"
14 #include "fpmodule.h"
15 #include "fpmodule.inl"
16 
17 #include <linux/uaccess.h>
18 
loadSingle(const unsigned int Fn,const unsigned int __user * pMem)19 static inline void loadSingle(const unsigned int Fn, const unsigned int __user *pMem)
20 {
21 	FPA11 *fpa11 = GET_FPA11();
22 	fpa11->fType[Fn] = typeSingle;
23 	get_user(fpa11->fpreg[Fn].fSingle, pMem);
24 }
25 
loadDouble(const unsigned int Fn,const unsigned int __user * pMem)26 static inline void loadDouble(const unsigned int Fn, const unsigned int __user *pMem)
27 {
28 	FPA11 *fpa11 = GET_FPA11();
29 	unsigned int *p;
30 	p = (unsigned int *) &fpa11->fpreg[Fn].fDouble;
31 	fpa11->fType[Fn] = typeDouble;
32 #ifdef __ARMEB__
33 	get_user(p[0], &pMem[0]);	/* sign & exponent */
34 	get_user(p[1], &pMem[1]);
35 #else
36 	get_user(p[0], &pMem[1]);
37 	get_user(p[1], &pMem[0]);	/* sign & exponent */
38 #endif
39 }
40 
41 #ifdef CONFIG_FPE_NWFPE_XP
loadExtended(const unsigned int Fn,const unsigned int __user * pMem)42 static inline void loadExtended(const unsigned int Fn, const unsigned int __user *pMem)
43 {
44 	FPA11 *fpa11 = GET_FPA11();
45 	unsigned int *p;
46 	p = (unsigned int *) &fpa11->fpreg[Fn].fExtended;
47 	fpa11->fType[Fn] = typeExtended;
48 	get_user(p[0], &pMem[0]);	/* sign & exponent */
49 #ifdef __ARMEB__
50 	get_user(p[1], &pMem[1]);	/* ms bits */
51 	get_user(p[2], &pMem[2]);	/* ls bits */
52 #else
53 	get_user(p[1], &pMem[2]);	/* ls bits */
54 	get_user(p[2], &pMem[1]);	/* ms bits */
55 #endif
56 }
57 #endif
58 
loadMultiple(const unsigned int Fn,const unsigned int __user * pMem)59 static inline void loadMultiple(const unsigned int Fn, const unsigned int __user *pMem)
60 {
61 	FPA11 *fpa11 = GET_FPA11();
62 	register unsigned int *p;
63 	unsigned long x;
64 
65 	p = (unsigned int *) &(fpa11->fpreg[Fn]);
66 	get_user(x, &pMem[0]);
67 	fpa11->fType[Fn] = (x >> 14) & 0x00000003;
68 
69 	switch (fpa11->fType[Fn]) {
70 	case typeSingle:
71 	case typeDouble:
72 		{
73 			get_user(p[0], &pMem[2]);	/* Single */
74 			get_user(p[1], &pMem[1]);	/* double msw */
75 			p[2] = 0;			/* empty */
76 		}
77 		break;
78 
79 #ifdef CONFIG_FPE_NWFPE_XP
80 	case typeExtended:
81 		{
82 			get_user(p[1], &pMem[2]);
83 			get_user(p[2], &pMem[1]);	/* msw */
84 			p[0] = (x & 0x80003fff);
85 		}
86 		break;
87 #endif
88 	}
89 }
90 
storeSingle(struct roundingData * roundData,const unsigned int Fn,unsigned int __user * pMem)91 static inline void storeSingle(struct roundingData *roundData, const unsigned int Fn, unsigned int __user *pMem)
92 {
93 	FPA11 *fpa11 = GET_FPA11();
94 	union {
95 		float32 f;
96 		unsigned int i[1];
97 	} val;
98 
99 	switch (fpa11->fType[Fn]) {
100 	case typeDouble:
101 		val.f = float64_to_float32(roundData, fpa11->fpreg[Fn].fDouble);
102 		break;
103 
104 #ifdef CONFIG_FPE_NWFPE_XP
105 	case typeExtended:
106 		val.f = floatx80_to_float32(roundData, fpa11->fpreg[Fn].fExtended);
107 		break;
108 #endif
109 
110 	default:
111 		val.f = fpa11->fpreg[Fn].fSingle;
112 	}
113 
114 	put_user(val.i[0], pMem);
115 }
116 
storeDouble(struct roundingData * roundData,const unsigned int Fn,unsigned int __user * pMem)117 static inline void storeDouble(struct roundingData *roundData, const unsigned int Fn, unsigned int __user *pMem)
118 {
119 	FPA11 *fpa11 = GET_FPA11();
120 	union {
121 		float64 f;
122 		unsigned int i[2];
123 	} val;
124 
125 	switch (fpa11->fType[Fn]) {
126 	case typeSingle:
127 		val.f = float32_to_float64(fpa11->fpreg[Fn].fSingle);
128 		break;
129 
130 #ifdef CONFIG_FPE_NWFPE_XP
131 	case typeExtended:
132 		val.f = floatx80_to_float64(roundData, fpa11->fpreg[Fn].fExtended);
133 		break;
134 #endif
135 
136 	default:
137 		val.f = fpa11->fpreg[Fn].fDouble;
138 	}
139 
140 #ifdef __ARMEB__
141 	put_user(val.i[0], &pMem[0]);	/* msw */
142 	put_user(val.i[1], &pMem[1]);	/* lsw */
143 #else
144 	put_user(val.i[1], &pMem[0]);	/* msw */
145 	put_user(val.i[0], &pMem[1]);	/* lsw */
146 #endif
147 }
148 
149 #ifdef CONFIG_FPE_NWFPE_XP
storeExtended(const unsigned int Fn,unsigned int __user * pMem)150 static inline void storeExtended(const unsigned int Fn, unsigned int __user *pMem)
151 {
152 	FPA11 *fpa11 = GET_FPA11();
153 	union {
154 		floatx80 f;
155 		unsigned int i[3];
156 	} val;
157 
158 	switch (fpa11->fType[Fn]) {
159 	case typeSingle:
160 		val.f = float32_to_floatx80(fpa11->fpreg[Fn].fSingle);
161 		break;
162 
163 	case typeDouble:
164 		val.f = float64_to_floatx80(fpa11->fpreg[Fn].fDouble);
165 		break;
166 
167 	default:
168 		val.f = fpa11->fpreg[Fn].fExtended;
169 	}
170 
171 	put_user(val.i[0], &pMem[0]);	/* sign & exp */
172 #ifdef __ARMEB__
173 	put_user(val.i[1], &pMem[1]);	/* msw */
174 	put_user(val.i[2], &pMem[2]);
175 #else
176 	put_user(val.i[1], &pMem[2]);
177 	put_user(val.i[2], &pMem[1]);	/* msw */
178 #endif
179 }
180 #endif
181 
storeMultiple(const unsigned int Fn,unsigned int __user * pMem)182 static inline void storeMultiple(const unsigned int Fn, unsigned int __user *pMem)
183 {
184 	FPA11 *fpa11 = GET_FPA11();
185 	register unsigned int nType, *p;
186 
187 	p = (unsigned int *) &(fpa11->fpreg[Fn]);
188 	nType = fpa11->fType[Fn];
189 
190 	switch (nType) {
191 	case typeSingle:
192 	case typeDouble:
193 		{
194 			put_user(p[0], &pMem[2]);	/* single */
195 			put_user(p[1], &pMem[1]);	/* double msw */
196 			put_user(nType << 14, &pMem[0]);
197 		}
198 		break;
199 
200 #ifdef CONFIG_FPE_NWFPE_XP
201 	case typeExtended:
202 		{
203 			put_user(p[2], &pMem[1]);	/* msw */
204 			put_user(p[1], &pMem[2]);
205 			put_user((p[0] & 0x80003fff) | (nType << 14), &pMem[0]);
206 		}
207 		break;
208 #endif
209 	}
210 }
211 
PerformLDF(const unsigned int opcode)212 unsigned int PerformLDF(const unsigned int opcode)
213 {
214 	unsigned int __user *pBase, *pAddress, *pFinal;
215 	unsigned int nRc = 1, write_back = WRITE_BACK(opcode);
216 
217 	pBase = (unsigned int __user *) readRegister(getRn(opcode));
218 	if (REG_PC == getRn(opcode)) {
219 		pBase += 2;
220 		write_back = 0;
221 	}
222 
223 	pFinal = pBase;
224 	if (BIT_UP_SET(opcode))
225 		pFinal += getOffset(opcode);
226 	else
227 		pFinal -= getOffset(opcode);
228 
229 	if (PREINDEXED(opcode))
230 		pAddress = pFinal;
231 	else
232 		pAddress = pBase;
233 
234 	switch (opcode & MASK_TRANSFER_LENGTH) {
235 	case TRANSFER_SINGLE:
236 		loadSingle(getFd(opcode), pAddress);
237 		break;
238 	case TRANSFER_DOUBLE:
239 		loadDouble(getFd(opcode), pAddress);
240 		break;
241 #ifdef CONFIG_FPE_NWFPE_XP
242 	case TRANSFER_EXTENDED:
243 		loadExtended(getFd(opcode), pAddress);
244 		break;
245 #endif
246 	default:
247 		nRc = 0;
248 	}
249 
250 	if (write_back)
251 		writeRegister(getRn(opcode), (unsigned long) pFinal);
252 	return nRc;
253 }
254 
PerformSTF(const unsigned int opcode)255 unsigned int PerformSTF(const unsigned int opcode)
256 {
257 	unsigned int __user *pBase, *pAddress, *pFinal;
258 	unsigned int nRc = 1, write_back = WRITE_BACK(opcode);
259 	struct roundingData roundData;
260 
261 	roundData.mode = SetRoundingMode(opcode);
262 	roundData.precision = SetRoundingPrecision(opcode);
263 	roundData.exception = 0;
264 
265 	pBase = (unsigned int __user *) readRegister(getRn(opcode));
266 	if (REG_PC == getRn(opcode)) {
267 		pBase += 2;
268 		write_back = 0;
269 	}
270 
271 	pFinal = pBase;
272 	if (BIT_UP_SET(opcode))
273 		pFinal += getOffset(opcode);
274 	else
275 		pFinal -= getOffset(opcode);
276 
277 	if (PREINDEXED(opcode))
278 		pAddress = pFinal;
279 	else
280 		pAddress = pBase;
281 
282 	switch (opcode & MASK_TRANSFER_LENGTH) {
283 	case TRANSFER_SINGLE:
284 		storeSingle(&roundData, getFd(opcode), pAddress);
285 		break;
286 	case TRANSFER_DOUBLE:
287 		storeDouble(&roundData, getFd(opcode), pAddress);
288 		break;
289 #ifdef CONFIG_FPE_NWFPE_XP
290 	case TRANSFER_EXTENDED:
291 		storeExtended(getFd(opcode), pAddress);
292 		break;
293 #endif
294 	default:
295 		nRc = 0;
296 	}
297 
298 	if (roundData.exception)
299 		float_raise(roundData.exception);
300 
301 	if (write_back)
302 		writeRegister(getRn(opcode), (unsigned long) pFinal);
303 	return nRc;
304 }
305 
PerformLFM(const unsigned int opcode)306 unsigned int PerformLFM(const unsigned int opcode)
307 {
308 	unsigned int __user *pBase, *pAddress, *pFinal;
309 	unsigned int i, Fd, write_back = WRITE_BACK(opcode);
310 
311 	pBase = (unsigned int __user *) readRegister(getRn(opcode));
312 	if (REG_PC == getRn(opcode)) {
313 		pBase += 2;
314 		write_back = 0;
315 	}
316 
317 	pFinal = pBase;
318 	if (BIT_UP_SET(opcode))
319 		pFinal += getOffset(opcode);
320 	else
321 		pFinal -= getOffset(opcode);
322 
323 	if (PREINDEXED(opcode))
324 		pAddress = pFinal;
325 	else
326 		pAddress = pBase;
327 
328 	Fd = getFd(opcode);
329 	for (i = getRegisterCount(opcode); i > 0; i--) {
330 		loadMultiple(Fd, pAddress);
331 		pAddress += 3;
332 		Fd++;
333 		if (Fd == 8)
334 			Fd = 0;
335 	}
336 
337 	if (write_back)
338 		writeRegister(getRn(opcode), (unsigned long) pFinal);
339 	return 1;
340 }
341 
PerformSFM(const unsigned int opcode)342 unsigned int PerformSFM(const unsigned int opcode)
343 {
344 	unsigned int __user *pBase, *pAddress, *pFinal;
345 	unsigned int i, Fd, write_back = WRITE_BACK(opcode);
346 
347 	pBase = (unsigned int __user *) readRegister(getRn(opcode));
348 	if (REG_PC == getRn(opcode)) {
349 		pBase += 2;
350 		write_back = 0;
351 	}
352 
353 	pFinal = pBase;
354 	if (BIT_UP_SET(opcode))
355 		pFinal += getOffset(opcode);
356 	else
357 		pFinal -= getOffset(opcode);
358 
359 	if (PREINDEXED(opcode))
360 		pAddress = pFinal;
361 	else
362 		pAddress = pBase;
363 
364 	Fd = getFd(opcode);
365 	for (i = getRegisterCount(opcode); i > 0; i--) {
366 		storeMultiple(Fd, pAddress);
367 		pAddress += 3;
368 		Fd++;
369 		if (Fd == 8)
370 			Fd = 0;
371 	}
372 
373 	if (write_back)
374 		writeRegister(getRn(opcode), (unsigned long) pFinal);
375 	return 1;
376 }
377 
EmulateCPDT(const unsigned int opcode)378 unsigned int EmulateCPDT(const unsigned int opcode)
379 {
380 	unsigned int nRc = 0;
381 
382 	if (LDF_OP(opcode)) {
383 		nRc = PerformLDF(opcode);
384 	} else if (LFM_OP(opcode)) {
385 		nRc = PerformLFM(opcode);
386 	} else if (STF_OP(opcode)) {
387 		nRc = PerformSTF(opcode);
388 	} else if (SFM_OP(opcode)) {
389 		nRc = PerformSFM(opcode);
390 	} else {
391 		nRc = 0;
392 	}
393 
394 	return nRc;
395 }
396