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
19static 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
26static 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
42static 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
59static 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
91static 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
117static 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
150static 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
182static 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
212unsigned 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
255unsigned 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
306unsigned 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
342unsigned 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
378unsigned 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