1 /*
2 * arch/sparc64/math-emu/math.c
3 *
4 * Copyright (C) 1997,1999 Jakub Jelinek (jj@ultra.linux.cz)
5 * Copyright (C) 1999 David S. Miller (davem@redhat.com)
6 *
7 * Emulation routines originate from soft-fp package, which is part
8 * of glibc and has appropriate copyrights in it.
9 */
10
11 #include <linux/types.h>
12 #include <linux/sched.h>
13 #include <linux/errno.h>
14 #include <linux/perf_event.h>
15
16 #include <asm/fpumacro.h>
17 #include <asm/ptrace.h>
18 #include <asm/uaccess.h>
19 #include <asm/cacheflush.h>
20
21 #include "sfp-util_64.h"
22 #include <math-emu/soft-fp.h>
23 #include <math-emu/single.h>
24 #include <math-emu/double.h>
25 #include <math-emu/quad.h>
26
27 /* QUAD - ftt == 3 */
28 #define FMOVQ 0x003
29 #define FNEGQ 0x007
30 #define FABSQ 0x00b
31 #define FSQRTQ 0x02b
32 #define FADDQ 0x043
33 #define FSUBQ 0x047
34 #define FMULQ 0x04b
35 #define FDIVQ 0x04f
36 #define FDMULQ 0x06e
37 #define FQTOX 0x083
38 #define FXTOQ 0x08c
39 #define FQTOS 0x0c7
40 #define FQTOD 0x0cb
41 #define FITOQ 0x0cc
42 #define FSTOQ 0x0cd
43 #define FDTOQ 0x0ce
44 #define FQTOI 0x0d3
45 /* SUBNORMAL - ftt == 2 */
46 #define FSQRTS 0x029
47 #define FSQRTD 0x02a
48 #define FADDS 0x041
49 #define FADDD 0x042
50 #define FSUBS 0x045
51 #define FSUBD 0x046
52 #define FMULS 0x049
53 #define FMULD 0x04a
54 #define FDIVS 0x04d
55 #define FDIVD 0x04e
56 #define FSMULD 0x069
57 #define FSTOX 0x081
58 #define FDTOX 0x082
59 #define FDTOS 0x0c6
60 #define FSTOD 0x0c9
61 #define FSTOI 0x0d1
62 #define FDTOI 0x0d2
63 #define FXTOS 0x084 /* Only Ultra-III generates this. */
64 #define FXTOD 0x088 /* Only Ultra-III generates this. */
65 #if 0 /* Optimized inline in sparc64/kernel/entry.S */
66 #define FITOS 0x0c4 /* Only Ultra-III generates this. */
67 #endif
68 #define FITOD 0x0c8 /* Only Ultra-III generates this. */
69 /* FPOP2 */
70 #define FCMPQ 0x053
71 #define FCMPEQ 0x057
72 #define FMOVQ0 0x003
73 #define FMOVQ1 0x043
74 #define FMOVQ2 0x083
75 #define FMOVQ3 0x0c3
76 #define FMOVQI 0x103
77 #define FMOVQX 0x183
78 #define FMOVQZ 0x027
79 #define FMOVQLE 0x047
80 #define FMOVQLZ 0x067
81 #define FMOVQNZ 0x0a7
82 #define FMOVQGZ 0x0c7
83 #define FMOVQGE 0x0e7
84
85 #define FSR_TEM_SHIFT 23UL
86 #define FSR_TEM_MASK (0x1fUL << FSR_TEM_SHIFT)
87 #define FSR_AEXC_SHIFT 5UL
88 #define FSR_AEXC_MASK (0x1fUL << FSR_AEXC_SHIFT)
89 #define FSR_CEXC_SHIFT 0UL
90 #define FSR_CEXC_MASK (0x1fUL << FSR_CEXC_SHIFT)
91
92 /* All routines returning an exception to raise should detect
93 * such exceptions _before_ rounding to be consistent with
94 * the behavior of the hardware in the implemented cases
95 * (and thus with the recommendations in the V9 architecture
96 * manual).
97 *
98 * We return 0 if a SIGFPE should be sent, 1 otherwise.
99 */
record_exception(struct pt_regs * regs,int eflag)100 static inline int record_exception(struct pt_regs *regs, int eflag)
101 {
102 u64 fsr = current_thread_info()->xfsr[0];
103 int would_trap;
104
105 /* Determine if this exception would have generated a trap. */
106 would_trap = (fsr & ((long)eflag << FSR_TEM_SHIFT)) != 0UL;
107
108 /* If trapping, we only want to signal one bit. */
109 if(would_trap != 0) {
110 eflag &= ((fsr & FSR_TEM_MASK) >> FSR_TEM_SHIFT);
111 if((eflag & (eflag - 1)) != 0) {
112 if(eflag & FP_EX_INVALID)
113 eflag = FP_EX_INVALID;
114 else if(eflag & FP_EX_OVERFLOW)
115 eflag = FP_EX_OVERFLOW;
116 else if(eflag & FP_EX_UNDERFLOW)
117 eflag = FP_EX_UNDERFLOW;
118 else if(eflag & FP_EX_DIVZERO)
119 eflag = FP_EX_DIVZERO;
120 else if(eflag & FP_EX_INEXACT)
121 eflag = FP_EX_INEXACT;
122 }
123 }
124
125 /* Set CEXC, here is the rule:
126 *
127 * In general all FPU ops will set one and only one
128 * bit in the CEXC field, this is always the case
129 * when the IEEE exception trap is enabled in TEM.
130 */
131 fsr &= ~(FSR_CEXC_MASK);
132 fsr |= ((long)eflag << FSR_CEXC_SHIFT);
133
134 /* Set the AEXC field, rule is:
135 *
136 * If a trap would not be generated, the
137 * CEXC just generated is OR'd into the
138 * existing value of AEXC.
139 */
140 if(would_trap == 0)
141 fsr |= ((long)eflag << FSR_AEXC_SHIFT);
142
143 /* If trapping, indicate fault trap type IEEE. */
144 if(would_trap != 0)
145 fsr |= (1UL << 14);
146
147 current_thread_info()->xfsr[0] = fsr;
148
149 /* If we will not trap, advance the program counter over
150 * the instruction being handled.
151 */
152 if(would_trap == 0) {
153 regs->tpc = regs->tnpc;
154 regs->tnpc += 4;
155 }
156
157 return (would_trap ? 0 : 1);
158 }
159
160 typedef union {
161 u32 s;
162 u64 d;
163 u64 q[2];
164 } *argp;
165
do_mathemu(struct pt_regs * regs,struct fpustate * f,bool illegal_insn_trap)166 int do_mathemu(struct pt_regs *regs, struct fpustate *f, bool illegal_insn_trap)
167 {
168 unsigned long pc = regs->tpc;
169 unsigned long tstate = regs->tstate;
170 u32 insn = 0;
171 int type = 0;
172 /* ftt tells which ftt it may happen in, r is rd, b is rs2 and a is rs1. The *u arg tells
173 whether the argument should be packed/unpacked (0 - do not unpack/pack, 1 - unpack/pack)
174 non-u args tells the size of the argument (0 - no argument, 1 - single, 2 - double, 3 - quad */
175 #define TYPE(ftt, r, ru, b, bu, a, au) type = (au << 2) | (a << 0) | (bu << 5) | (b << 3) | (ru << 8) | (r << 6) | (ftt << 9)
176 int freg;
177 static u64 zero[2] = { 0L, 0L };
178 int flags;
179 FP_DECL_EX;
180 FP_DECL_S(SA); FP_DECL_S(SB); FP_DECL_S(SR);
181 FP_DECL_D(DA); FP_DECL_D(DB); FP_DECL_D(DR);
182 FP_DECL_Q(QA); FP_DECL_Q(QB); FP_DECL_Q(QR);
183 int IR;
184 long XR, xfsr;
185
186 if (tstate & TSTATE_PRIV)
187 die_if_kernel("unfinished/unimplemented FPop from kernel", regs);
188 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
189 if (test_thread_flag(TIF_32BIT))
190 pc = (u32)pc;
191 if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
192 if ((insn & 0xc1f80000) == 0x81a00000) /* FPOP1 */ {
193 switch ((insn >> 5) & 0x1ff) {
194 /* QUAD - ftt == 3 */
195 case FMOVQ:
196 case FNEGQ:
197 case FABSQ: TYPE(3,3,0,3,0,0,0); break;
198 case FSQRTQ: TYPE(3,3,1,3,1,0,0); break;
199 case FADDQ:
200 case FSUBQ:
201 case FMULQ:
202 case FDIVQ: TYPE(3,3,1,3,1,3,1); break;
203 case FDMULQ: TYPE(3,3,1,2,1,2,1); break;
204 case FQTOX: TYPE(3,2,0,3,1,0,0); break;
205 case FXTOQ: TYPE(3,3,1,2,0,0,0); break;
206 case FQTOS: TYPE(3,1,1,3,1,0,0); break;
207 case FQTOD: TYPE(3,2,1,3,1,0,0); break;
208 case FITOQ: TYPE(3,3,1,1,0,0,0); break;
209 case FSTOQ: TYPE(3,3,1,1,1,0,0); break;
210 case FDTOQ: TYPE(3,3,1,2,1,0,0); break;
211 case FQTOI: TYPE(3,1,0,3,1,0,0); break;
212
213 /* We can get either unimplemented or unfinished
214 * for these cases. Pre-Niagara systems generate
215 * unfinished fpop for SUBNORMAL cases, and Niagara
216 * always gives unimplemented fpop for fsqrt{s,d}.
217 */
218 case FSQRTS: {
219 unsigned long x = current_thread_info()->xfsr[0];
220
221 x = (x >> 14) & 0x7;
222 TYPE(x,1,1,1,1,0,0);
223 break;
224 }
225
226 case FSQRTD: {
227 unsigned long x = current_thread_info()->xfsr[0];
228
229 x = (x >> 14) & 0x7;
230 TYPE(x,2,1,2,1,0,0);
231 break;
232 }
233
234 /* SUBNORMAL - ftt == 2 */
235 case FADDD:
236 case FSUBD:
237 case FMULD:
238 case FDIVD: TYPE(2,2,1,2,1,2,1); break;
239 case FADDS:
240 case FSUBS:
241 case FMULS:
242 case FDIVS: TYPE(2,1,1,1,1,1,1); break;
243 case FSMULD: TYPE(2,2,1,1,1,1,1); break;
244 case FSTOX: TYPE(2,2,0,1,1,0,0); break;
245 case FDTOX: TYPE(2,2,0,2,1,0,0); break;
246 case FDTOS: TYPE(2,1,1,2,1,0,0); break;
247 case FSTOD: TYPE(2,2,1,1,1,0,0); break;
248 case FSTOI: TYPE(2,1,0,1,1,0,0); break;
249 case FDTOI: TYPE(2,1,0,2,1,0,0); break;
250
251 /* Only Ultra-III generates these */
252 case FXTOS: TYPE(2,1,1,2,0,0,0); break;
253 case FXTOD: TYPE(2,2,1,2,0,0,0); break;
254 #if 0 /* Optimized inline in sparc64/kernel/entry.S */
255 case FITOS: TYPE(2,1,1,1,0,0,0); break;
256 #endif
257 case FITOD: TYPE(2,2,1,1,0,0,0); break;
258 }
259 }
260 else if ((insn & 0xc1f80000) == 0x81a80000) /* FPOP2 */ {
261 IR = 2;
262 switch ((insn >> 5) & 0x1ff) {
263 case FCMPQ: TYPE(3,0,0,3,1,3,1); break;
264 case FCMPEQ: TYPE(3,0,0,3,1,3,1); break;
265 /* Now the conditional fmovq support */
266 case FMOVQ0:
267 case FMOVQ1:
268 case FMOVQ2:
269 case FMOVQ3:
270 /* fmovq %fccX, %fY, %fZ */
271 if (!((insn >> 11) & 3))
272 XR = current_thread_info()->xfsr[0] >> 10;
273 else
274 XR = current_thread_info()->xfsr[0] >> (30 + ((insn >> 10) & 0x6));
275 XR &= 3;
276 IR = 0;
277 switch ((insn >> 14) & 0x7) {
278 /* case 0: IR = 0; break; */ /* Never */
279 case 1: if (XR) IR = 1; break; /* Not Equal */
280 case 2: if (XR == 1 || XR == 2) IR = 1; break; /* Less or Greater */
281 case 3: if (XR & 1) IR = 1; break; /* Unordered or Less */
282 case 4: if (XR == 1) IR = 1; break; /* Less */
283 case 5: if (XR & 2) IR = 1; break; /* Unordered or Greater */
284 case 6: if (XR == 2) IR = 1; break; /* Greater */
285 case 7: if (XR == 3) IR = 1; break; /* Unordered */
286 }
287 if ((insn >> 14) & 8)
288 IR ^= 1;
289 break;
290 case FMOVQI:
291 case FMOVQX:
292 /* fmovq %[ix]cc, %fY, %fZ */
293 XR = regs->tstate >> 32;
294 if ((insn >> 5) & 0x80)
295 XR >>= 4;
296 XR &= 0xf;
297 IR = 0;
298 freg = ((XR >> 2) ^ XR) & 2;
299 switch ((insn >> 14) & 0x7) {
300 /* case 0: IR = 0; break; */ /* Never */
301 case 1: if (XR & 4) IR = 1; break; /* Equal */
302 case 2: if ((XR & 4) || freg) IR = 1; break; /* Less or Equal */
303 case 3: if (freg) IR = 1; break; /* Less */
304 case 4: if (XR & 5) IR = 1; break; /* Less or Equal Unsigned */
305 case 5: if (XR & 1) IR = 1; break; /* Carry Set */
306 case 6: if (XR & 8) IR = 1; break; /* Negative */
307 case 7: if (XR & 2) IR = 1; break; /* Overflow Set */
308 }
309 if ((insn >> 14) & 8)
310 IR ^= 1;
311 break;
312 case FMOVQZ:
313 case FMOVQLE:
314 case FMOVQLZ:
315 case FMOVQNZ:
316 case FMOVQGZ:
317 case FMOVQGE:
318 freg = (insn >> 14) & 0x1f;
319 if (!freg)
320 XR = 0;
321 else if (freg < 16)
322 XR = regs->u_regs[freg];
323 else if (!test_thread_64bit_stack(regs->u_regs[UREG_FP])) {
324 struct reg_window32 __user *win32;
325 flushw_user ();
326 win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
327 get_user(XR, &win32->locals[freg - 16]);
328 } else {
329 struct reg_window __user *win;
330 flushw_user ();
331 win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS);
332 get_user(XR, &win->locals[freg - 16]);
333 }
334 IR = 0;
335 switch ((insn >> 10) & 3) {
336 case 1: if (!XR) IR = 1; break; /* Register Zero */
337 case 2: if (XR <= 0) IR = 1; break; /* Register Less Than or Equal to Zero */
338 case 3: if (XR < 0) IR = 1; break; /* Register Less Than Zero */
339 }
340 if ((insn >> 10) & 4)
341 IR ^= 1;
342 break;
343 }
344 if (IR == 0) {
345 /* The fmov test was false. Do a nop instead */
346 current_thread_info()->xfsr[0] &= ~(FSR_CEXC_MASK);
347 regs->tpc = regs->tnpc;
348 regs->tnpc += 4;
349 return 1;
350 } else if (IR == 1) {
351 /* Change the instruction into plain fmovq */
352 insn = (insn & 0x3e00001f) | 0x81a00060;
353 TYPE(3,3,0,3,0,0,0);
354 }
355 }
356 }
357 if (type) {
358 argp rs1 = NULL, rs2 = NULL, rd = NULL;
359
360 /* Starting with UltraSPARC-T2, the cpu does not set the FP Trap
361 * Type field in the %fsr to unimplemented_FPop. Nor does it
362 * use the fp_exception_other trap. Instead it signals an
363 * illegal instruction and leaves the FP trap type field of
364 * the %fsr unchanged.
365 */
366 if (!illegal_insn_trap) {
367 int ftt = (current_thread_info()->xfsr[0] >> 14) & 0x7;
368 if (ftt != (type >> 9))
369 goto err;
370 }
371 current_thread_info()->xfsr[0] &= ~0x1c000;
372 freg = ((insn >> 14) & 0x1f);
373 switch (type & 0x3) {
374 case 3: if (freg & 2) {
375 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
376 goto err;
377 }
378 case 2: freg = ((freg & 1) << 5) | (freg & 0x1e);
379 case 1: rs1 = (argp)&f->regs[freg];
380 flags = (freg < 32) ? FPRS_DL : FPRS_DU;
381 if (!(current_thread_info()->fpsaved[0] & flags))
382 rs1 = (argp)&zero;
383 break;
384 }
385 switch (type & 0x7) {
386 case 7: FP_UNPACK_QP (QA, rs1); break;
387 case 6: FP_UNPACK_DP (DA, rs1); break;
388 case 5: FP_UNPACK_SP (SA, rs1); break;
389 }
390 freg = (insn & 0x1f);
391 switch ((type >> 3) & 0x3) {
392 case 3: if (freg & 2) {
393 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
394 goto err;
395 }
396 case 2: freg = ((freg & 1) << 5) | (freg & 0x1e);
397 case 1: rs2 = (argp)&f->regs[freg];
398 flags = (freg < 32) ? FPRS_DL : FPRS_DU;
399 if (!(current_thread_info()->fpsaved[0] & flags))
400 rs2 = (argp)&zero;
401 break;
402 }
403 switch ((type >> 3) & 0x7) {
404 case 7: FP_UNPACK_QP (QB, rs2); break;
405 case 6: FP_UNPACK_DP (DB, rs2); break;
406 case 5: FP_UNPACK_SP (SB, rs2); break;
407 }
408 freg = ((insn >> 25) & 0x1f);
409 switch ((type >> 6) & 0x3) {
410 case 3: if (freg & 2) {
411 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
412 goto err;
413 }
414 case 2: freg = ((freg & 1) << 5) | (freg & 0x1e);
415 case 1: rd = (argp)&f->regs[freg];
416 flags = (freg < 32) ? FPRS_DL : FPRS_DU;
417 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
418 current_thread_info()->fpsaved[0] = FPRS_FEF;
419 current_thread_info()->gsr[0] = 0;
420 }
421 if (!(current_thread_info()->fpsaved[0] & flags)) {
422 if (freg < 32)
423 memset(f->regs, 0, 32*sizeof(u32));
424 else
425 memset(f->regs+32, 0, 32*sizeof(u32));
426 }
427 current_thread_info()->fpsaved[0] |= flags;
428 break;
429 }
430 switch ((insn >> 5) & 0x1ff) {
431 /* + */
432 case FADDS: FP_ADD_S (SR, SA, SB); break;
433 case FADDD: FP_ADD_D (DR, DA, DB); break;
434 case FADDQ: FP_ADD_Q (QR, QA, QB); break;
435 /* - */
436 case FSUBS: FP_SUB_S (SR, SA, SB); break;
437 case FSUBD: FP_SUB_D (DR, DA, DB); break;
438 case FSUBQ: FP_SUB_Q (QR, QA, QB); break;
439 /* * */
440 case FMULS: FP_MUL_S (SR, SA, SB); break;
441 case FSMULD: FP_CONV (D, S, 1, 1, DA, SA);
442 FP_CONV (D, S, 1, 1, DB, SB);
443 case FMULD: FP_MUL_D (DR, DA, DB); break;
444 case FDMULQ: FP_CONV (Q, D, 2, 1, QA, DA);
445 FP_CONV (Q, D, 2, 1, QB, DB);
446 case FMULQ: FP_MUL_Q (QR, QA, QB); break;
447 /* / */
448 case FDIVS: FP_DIV_S (SR, SA, SB); break;
449 case FDIVD: FP_DIV_D (DR, DA, DB); break;
450 case FDIVQ: FP_DIV_Q (QR, QA, QB); break;
451 /* sqrt */
452 case FSQRTS: FP_SQRT_S (SR, SB); break;
453 case FSQRTD: FP_SQRT_D (DR, DB); break;
454 case FSQRTQ: FP_SQRT_Q (QR, QB); break;
455 /* mov */
456 case FMOVQ: rd->q[0] = rs2->q[0]; rd->q[1] = rs2->q[1]; break;
457 case FABSQ: rd->q[0] = rs2->q[0] & 0x7fffffffffffffffUL; rd->q[1] = rs2->q[1]; break;
458 case FNEGQ: rd->q[0] = rs2->q[0] ^ 0x8000000000000000UL; rd->q[1] = rs2->q[1]; break;
459 /* float to int */
460 case FSTOI: FP_TO_INT_S (IR, SB, 32, 1); break;
461 case FDTOI: FP_TO_INT_D (IR, DB, 32, 1); break;
462 case FQTOI: FP_TO_INT_Q (IR, QB, 32, 1); break;
463 case FSTOX: FP_TO_INT_S (XR, SB, 64, 1); break;
464 case FDTOX: FP_TO_INT_D (XR, DB, 64, 1); break;
465 case FQTOX: FP_TO_INT_Q (XR, QB, 64, 1); break;
466 /* int to float */
467 case FITOQ: IR = rs2->s; FP_FROM_INT_Q (QR, IR, 32, int); break;
468 case FXTOQ: XR = rs2->d; FP_FROM_INT_Q (QR, XR, 64, long); break;
469 /* Only Ultra-III generates these */
470 case FXTOS: XR = rs2->d; FP_FROM_INT_S (SR, XR, 64, long); break;
471 case FXTOD: XR = rs2->d; FP_FROM_INT_D (DR, XR, 64, long); break;
472 #if 0 /* Optimized inline in sparc64/kernel/entry.S */
473 case FITOS: IR = rs2->s; FP_FROM_INT_S (SR, IR, 32, int); break;
474 #endif
475 case FITOD: IR = rs2->s; FP_FROM_INT_D (DR, IR, 32, int); break;
476 /* float to float */
477 case FSTOD: FP_CONV (D, S, 1, 1, DR, SB); break;
478 case FSTOQ: FP_CONV (Q, S, 2, 1, QR, SB); break;
479 case FDTOQ: FP_CONV (Q, D, 2, 1, QR, DB); break;
480 case FDTOS: FP_CONV (S, D, 1, 1, SR, DB); break;
481 case FQTOS: FP_CONV (S, Q, 1, 2, SR, QB); break;
482 case FQTOD: FP_CONV (D, Q, 1, 2, DR, QB); break;
483 /* comparison */
484 case FCMPQ:
485 case FCMPEQ:
486 FP_CMP_Q(XR, QB, QA, 3);
487 if (XR == 3 &&
488 (((insn >> 5) & 0x1ff) == FCMPEQ ||
489 FP_ISSIGNAN_Q(QA) ||
490 FP_ISSIGNAN_Q(QB)))
491 FP_SET_EXCEPTION (FP_EX_INVALID);
492 }
493 if (!FP_INHIBIT_RESULTS) {
494 switch ((type >> 6) & 0x7) {
495 case 0: xfsr = current_thread_info()->xfsr[0];
496 if (XR == -1) XR = 2;
497 switch (freg & 3) {
498 /* fcc0, 1, 2, 3 */
499 case 0: xfsr &= ~0xc00; xfsr |= (XR << 10); break;
500 case 1: xfsr &= ~0x300000000UL; xfsr |= (XR << 32); break;
501 case 2: xfsr &= ~0xc00000000UL; xfsr |= (XR << 34); break;
502 case 3: xfsr &= ~0x3000000000UL; xfsr |= (XR << 36); break;
503 }
504 current_thread_info()->xfsr[0] = xfsr;
505 break;
506 case 1: rd->s = IR; break;
507 case 2: rd->d = XR; break;
508 case 5: FP_PACK_SP (rd, SR); break;
509 case 6: FP_PACK_DP (rd, DR); break;
510 case 7: FP_PACK_QP (rd, QR); break;
511 }
512 }
513
514 if(_fex != 0)
515 return record_exception(regs, _fex);
516
517 /* Success and no exceptions detected. */
518 current_thread_info()->xfsr[0] &= ~(FSR_CEXC_MASK);
519 regs->tpc = regs->tnpc;
520 regs->tnpc += 4;
521 return 1;
522 }
523 err: return 0;
524 }
525