1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * linux/arch/arm/vfp/vfp.h
4 *
5 * Copyright (C) 2004 ARM Limited.
6 * Written by Deep Blue Solutions Limited.
7 */
8
9 static inline u32 vfp_shiftright32jamming(u32 val, unsigned int shift)
10 {
11 if (shift) {
12 if (shift < 32)
13 val = val >> shift | ((val << (32 - shift)) != 0);
14 else
15 val = val != 0;
16 }
17 return val;
18 }
19
20 static inline u64 vfp_shiftright64jamming(u64 val, unsigned int shift)
21 {
22 if (shift) {
23 if (shift < 64)
24 val = val >> shift | ((val << (64 - shift)) != 0);
25 else
26 val = val != 0;
27 }
28 return val;
29 }
30
31 static inline u32 vfp_hi64to32jamming(u64 val)
32 {
33 u32 v;
34
35 asm(
36 "cmp %Q1, #1 @ vfp_hi64to32jamming\n\t"
37 "movcc %0, %R1\n\t"
38 "orrcs %0, %R1, #1"
39 : "=r" (v) : "r" (val) : "cc");
40
41 return v;
42 }
43
44 static inline void add128(u64 *resh, u64 *resl, u64 nh, u64 nl, u64 mh, u64 ml)
45 {
46 asm( "adds %Q0, %Q2, %Q4\n\t"
47 "adcs %R0, %R2, %R4\n\t"
48 "adcs %Q1, %Q3, %Q5\n\t"
49 "adc %R1, %R3, %R5"
50 : "=r" (nl), "=r" (nh)
51 : "" (nl), "1" (nh), "r" (ml), "r" (mh)
52 : "cc");
53 *resh = nh;
54 *resl = nl;
55 }
56
57 static inline void sub128(u64 *resh, u64 *resl, u64 nh, u64 nl, u64 mh, u64 ml)
58 {
59 asm( "subs %Q0, %Q2, %Q4\n\t"
60 "sbcs %R0, %R2, %R4\n\t"
61 "sbcs %Q1, %Q3, %Q5\n\t"
62 "sbc %R1, %R3, %R5\n\t"
63 : "=r" (nl), "=r" (nh)
64 : "" (nl), "1" (nh), "r" (ml), "r" (mh)
65 : "cc");
66 *resh = nh;
67 *resl = nl;
68 }
69
70 static inline void mul64to128(u64 *resh, u64 *resl, u64 n, u64 m)
71 {
72 u32 nh, nl, mh, ml;
73 u64 rh, rma, rmb, rl;
74
75 nl = n;
76 ml = m;
77 rl = (u64)nl * ml;
78
79 nh = n >> 32;
80 rma = (u64)nh * ml;
81
82 mh = m >> 32;
83 rmb = (u64)nl * mh;
84 rma += rmb;
85
86 rh = (u64)nh * mh;
87 rh += ((u64)(rma < rmb) << 32) + (rma >> 32);
88
89 rma <<= 32;
90 rl += rma;
91 rh += (rl < rma);
92
93 *resl = rl;
94 *resh = rh;
95 }
96
97 static inline void shift64left(u64 *resh, u64 *resl, u64 n)
98 {
99 *resh = n >> 63;
100 *resl = n << 1;
101 }
102
103 static inline u64 vfp_hi64multiply64(u64 n, u64 m)
104 {
105 u64 rh, rl;
106 mul64to128(&rh, &rl, n, m);
107 return rh | (rl != 0);
108 }
109
110 static inline u64 vfp_estimate_div128to64(u64 nh, u64 nl, u64 m)
111 {
112 u64 mh, ml, remh, reml, termh, terml, z;
113
114 if (nh >= m)
115 return ~0ULL;
116 mh = m >> 32;
117 if (mh << 32 <= nh) {
118 z = 0xffffffff00000000ULL;
119 } else {
120 z = nh;
121 do_div(z, mh);
122 z <<= 32;
123 }
124 mul64to128(&termh, &terml, m, z);
125 sub128(&remh, &reml, nh, nl, termh, terml);
126 ml = m << 32;
127 while ((s64)remh < 0) {
128 z -= 0x100000000ULL;
129 add128(&remh, &reml, remh, reml, mh, ml);
130 }
131 remh = (remh << 32) | (reml >> 32);
132 if (mh << 32 <= remh) {
133 z |= 0xffffffff;
134 } else {
135 do_div(remh, mh);
136 z |= remh;
137 }
138 return z;
139 }
140
141 /*
142 * Operations on unpacked elements
143 */
144 #define vfp_sign_negate(sign) (sign ^ 0x8000)
145
146 /*
147 * Single-precision
148 */
149 struct vfp_single {
150 s16 exponent;
151 u16 sign;
152 u32 significand;
153 };
154
155 asmlinkage s32 vfp_get_float(unsigned int reg);
156 asmlinkage void vfp_put_float(s32 val, unsigned int reg);
157
158 /*
159 * VFP_SINGLE_MANTISSA_BITS - number of bits in the mantissa
160 * VFP_SINGLE_EXPONENT_BITS - number of bits in the exponent
161 * VFP_SINGLE_LOW_BITS - number of low bits in the unpacked significand
162 * which are not propagated to the float upon packing.
163 */
164 #define VFP_SINGLE_MANTISSA_BITS (23)
165 #define VFP_SINGLE_EXPONENT_BITS (8)
166 #define VFP_SINGLE_LOW_BITS (32 - VFP_SINGLE_MANTISSA_BITS - 2)
167 #define VFP_SINGLE_LOW_BITS_MASK ((1 << VFP_SINGLE_LOW_BITS) - 1)
168
169 /*
170 * The bit in an unpacked float which indicates that it is a quiet NaN
171 */
172 #define VFP_SINGLE_SIGNIFICAND_QNAN (1 << (VFP_SINGLE_MANTISSA_BITS - 1 + VFP_SINGLE_LOW_BITS))
173
174 /*
175 * Operations on packed single-precision numbers
176 */
177 #define vfp_single_packed_sign(v) ((v) & 0x80000000)
178 #define vfp_single_packed_negate(v) ((v) ^ 0x80000000)
179 #define vfp_single_packed_abs(v) ((v) & ~0x80000000)
180 #define vfp_single_packed_exponent(v) (((v) >> VFP_SINGLE_MANTISSA_BITS) & ((1 << VFP_SINGLE_EXPONENT_BITS) - 1))
181 #define vfp_single_packed_mantissa(v) ((v) & ((1 << VFP_SINGLE_MANTISSA_BITS) - 1))
182
183 /*
184 * Unpack a single-precision float. Note that this returns the magnitude
185 * of the single-precision float mantissa with the 1. if necessary,
186 * aligned to bit 30.
187 */
188 static inline void vfp_single_unpack(struct vfp_single *s, s32 val)
189 {
190 u32 significand;
191
192 s->sign = vfp_single_packed_sign(val) >> 16,
193 s->exponent = vfp_single_packed_exponent(val);
194
195 significand = (u32) val;
196 significand = (significand << (32 - VFP_SINGLE_MANTISSA_BITS)) >> 2;
197 if (s->exponent && s->exponent != 255)
198 significand |= 0x40000000;
199 s->significand = significand;
200 }
201
202 /*
203 * Re-pack a single-precision float. This assumes that the float is
204 * already normalised such that the MSB is bit 30, _not_ bit 31.
205 */
206 static inline s32 vfp_single_pack(struct vfp_single *s)
207 {
208 u32 val;
209 val = (s->sign << 16) +
210 (s->exponent << VFP_SINGLE_MANTISSA_BITS) +
211 (s->significand >> VFP_SINGLE_LOW_BITS);
212 return (s32)val;
213 }
214
215 #define VFP_NUMBER (1<<0)
216 #define VFP_ZERO (1<<1)
217 #define VFP_DENORMAL (1<<2)
218 #define VFP_INFINITY (1<<3)
219 #define VFP_NAN (1<<4)
220 #define VFP_NAN_SIGNAL (1<<5)
221
222 #define VFP_QNAN (VFP_NAN)
223 #define VFP_SNAN (VFP_NAN|VFP_NAN_SIGNAL)
224
225 static inline int vfp_single_type(struct vfp_single *s)
226 {
227 int type = VFP_NUMBER;
228 if (s->exponent == 255) {
229 if (s->significand == 0)
230 type = VFP_INFINITY;
231 else if (s->significand & VFP_SINGLE_SIGNIFICAND_QNAN)
232 type = VFP_QNAN;
233 else
234 type = VFP_SNAN;
235 } else if (s->exponent == 0) {
236 if (s->significand == 0)
237 type |= VFP_ZERO;
238 else
239 type |= VFP_DENORMAL;
240 }
241 return type;
242 }
243
244 #ifndef DEBUG
245 #define vfp_single_normaliseround(sd,vsd,fpscr,except,func) __vfp_single_normaliseround(sd,vsd,fpscr,except)
246 u32 __vfp_single_normaliseround(int sd, struct vfp_single *vs, u32 fpscr, u32 exceptions);
247 #else
248 u32 vfp_single_normaliseround(int sd, struct vfp_single *vs, u32 fpscr, u32 exceptions, const char *func);
249 #endif
250
251 /*
252 * Double-precision
253 */
254 struct vfp_double {
255 s16 exponent;
256 u16 sign;
257 u64 significand;
258 };
259
260 /*
261 * VFP_REG_ZERO is a special register number for vfp_get_double
262 * which returns (double)0.0. This is useful for the compare with
263 * zero instructions.
264 */
265 #ifdef CONFIG_VFPv3
266 #define VFP_REG_ZERO 32
267 #else
268 #define VFP_REG_ZERO 16
269 #endif
270 asmlinkage u64 vfp_get_double(unsigned int reg);
271 asmlinkage void vfp_put_double(u64 val, unsigned int reg);
272
273 #define VFP_DOUBLE_MANTISSA_BITS (52)
274 #define VFP_DOUBLE_EXPONENT_BITS (11)
275 #define VFP_DOUBLE_LOW_BITS (64 - VFP_DOUBLE_MANTISSA_BITS - 2)
276 #define VFP_DOUBLE_LOW_BITS_MASK ((1 << VFP_DOUBLE_LOW_BITS) - 1)
277
278 /*
279 * The bit in an unpacked double which indicates that it is a quiet NaN
280 */
281 #define VFP_DOUBLE_SIGNIFICAND_QNAN (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1 + VFP_DOUBLE_LOW_BITS))
282
283 /*
284 * Operations on packed single-precision numbers
285 */
286 #define vfp_double_packed_sign(v) ((v) & (1ULL << 63))
287 #define vfp_double_packed_negate(v) ((v) ^ (1ULL << 63))
288 #define vfp_double_packed_abs(v) ((v) & ~(1ULL << 63))
289 #define vfp_double_packed_exponent(v) (((v) >> VFP_DOUBLE_MANTISSA_BITS) & ((1 << VFP_DOUBLE_EXPONENT_BITS) - 1))
290 #define vfp_double_packed_mantissa(v) ((v) & ((1ULL << VFP_DOUBLE_MANTISSA_BITS) - 1))
291
292 /*
293 * Unpack a double-precision float. Note that this returns the magnitude
294 * of the double-precision float mantissa with the 1. if necessary,
295 * aligned to bit 62.
296 */
297 static inline void vfp_double_unpack(struct vfp_double *s, s64 val)
298 {
299 u64 significand;
300
301 s->sign = vfp_double_packed_sign(val) >> 48;
302 s->exponent = vfp_double_packed_exponent(val);
303
304 significand = (u64) val;
305 significand = (significand << (64 - VFP_DOUBLE_MANTISSA_BITS)) >> 2;
306 if (s->exponent && s->exponent != 2047)
307 significand |= (1ULL << 62);
308 s->significand = significand;
309 }
310
311 /*
312 * Re-pack a double-precision float. This assumes that the float is
313 * already normalised such that the MSB is bit 30, _not_ bit 31.
314 */
315 static inline s64 vfp_double_pack(struct vfp_double *s)
316 {
317 u64 val;
318 val = ((u64)s->sign << 48) +
319 ((u64)s->exponent << VFP_DOUBLE_MANTISSA_BITS) +
320 (s->significand >> VFP_DOUBLE_LOW_BITS);
321 return (s64)val;
322 }
323
324 static inline int vfp_double_type(struct vfp_double *s)
325 {
326 int type = VFP_NUMBER;
327 if (s->exponent == 2047) {
328 if (s->significand == 0)
329 type = VFP_INFINITY;
330 else if (s->significand & VFP_DOUBLE_SIGNIFICAND_QNAN)
331 type = VFP_QNAN;
332 else
333 type = VFP_SNAN;
334 } else if (s->exponent == 0) {
335 if (s->significand == 0)
336 type |= VFP_ZERO;
337 else
338 type |= VFP_DENORMAL;
339 }
340 return type;
341 }
342
343 u32 vfp_double_normaliseround(int dd, struct vfp_double *vd, u32 fpscr, u32 exceptions, const char *func);
344
345 u32 vfp_estimate_sqrt_significand(u32 exponent, u32 significand);
346
347 /*
348 * A special flag to tell the normalisation code not to normalise.
349 */
350 #define VFP_NAN_FLAG 0x100
351
352 /*
353 * A bit pattern used to indicate the initial (unset) value of the
354 * exception mask, in case nothing handles an instruction. This
355 * doesn't include the NAN flag, which get masked out before
356 * we check for an error.
357 */
358 #define VFP_EXCEPTION_ERROR ((u32)-1 & ~VFP_NAN_FLAG)
359
360 /*
361 * A flag to tell vfp instruction type.
362 * OP_SCALAR - this operation always operates in scalar mode
363 * OP_SD - the instruction exceptionally writes to a single precision result.
364 * OP_DD - the instruction exceptionally writes to a double precision result.
365 * OP_SM - the instruction exceptionally reads from a single precision operand.
366 */
367 #define OP_SCALAR (1 << 0)
368 #define OP_SD (1 << 1)
369 #define OP_DD (1 << 1)
370 #define OP_SM (1 << 2)
371
372 struct op {
373 u32 (* const fn)(int dd, int dn, int dm, u32 fpscr);
374 u32 flags;
375 };
376
377 asmlinkage void vfp_save_state(void *location, u32 fpexc);
378 asmlinkage u32 vfp_load_state(const void *location);
379
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.