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8#include <linux/module.h>
9#include <linux/regset.h>
10#include <linux/sched.h>
11
12#include <asm/sigcontext.h>
13#include <asm/processor.h>
14#include <asm/math_emu.h>
15#include <asm/uaccess.h>
16#include <asm/ptrace.h>
17#include <asm/i387.h>
18#include <asm/user.h>
19
20#ifdef CONFIG_X86_64
21# include <asm/sigcontext32.h>
22# include <asm/user32.h>
23#else
24# define save_i387_xstate_ia32 save_i387_xstate
25# define restore_i387_xstate_ia32 restore_i387_xstate
26# define _fpstate_ia32 _fpstate
27# define _xstate_ia32 _xstate
28# define sig_xstate_ia32_size sig_xstate_size
29# define fx_sw_reserved_ia32 fx_sw_reserved
30# define user_i387_ia32_struct user_i387_struct
31# define user32_fxsr_struct user_fxsr_struct
32#endif
33
34#ifdef CONFIG_MATH_EMULATION
35# define HAVE_HWFP (boot_cpu_data.hard_math)
36#else
37# define HAVE_HWFP 1
38#endif
39
40static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
41unsigned int xstate_size;
42unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32);
43static struct i387_fxsave_struct fx_scratch __cpuinitdata;
44
45void __cpuinit mxcsr_feature_mask_init(void)
46{
47 unsigned long mask = 0;
48
49 clts();
50 if (cpu_has_fxsr) {
51 memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct));
52 asm volatile("fxsave %0" : : "m" (fx_scratch));
53 mask = fx_scratch.mxcsr_mask;
54 if (mask == 0)
55 mask = 0x0000ffbf;
56 }
57 mxcsr_feature_mask &= mask;
58 stts();
59}
60
61void __cpuinit init_thread_xstate(void)
62{
63 if (!HAVE_HWFP) {
64 xstate_size = sizeof(struct i387_soft_struct);
65 return;
66 }
67
68 if (cpu_has_xsave) {
69 xsave_cntxt_init();
70 return;
71 }
72
73 if (cpu_has_fxsr)
74 xstate_size = sizeof(struct i387_fxsave_struct);
75#ifdef CONFIG_X86_32
76 else
77 xstate_size = sizeof(struct i387_fsave_struct);
78#endif
79}
80
81#ifdef CONFIG_X86_64
82
83
84
85
86void __cpuinit fpu_init(void)
87{
88 unsigned long oldcr0 = read_cr0();
89
90 set_in_cr4(X86_CR4_OSFXSR);
91 set_in_cr4(X86_CR4_OSXMMEXCPT);
92
93 write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM));
94
95
96
97
98 if (!smp_processor_id())
99 init_thread_xstate();
100 xsave_init();
101
102 mxcsr_feature_mask_init();
103
104 if (cpu_has_xsave)
105 current_thread_info()->status = TS_XSAVE;
106 else
107 current_thread_info()->status = 0;
108 clear_used_math();
109}
110#endif
111
112
113
114
115
116
117
118int init_fpu(struct task_struct *tsk)
119{
120 if (tsk_used_math(tsk)) {
121 if (HAVE_HWFP && tsk == current)
122 unlazy_fpu(tsk);
123 return 0;
124 }
125
126
127
128
129 if (!tsk->thread.xstate) {
130 tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
131 GFP_KERNEL);
132 if (!tsk->thread.xstate)
133 return -ENOMEM;
134 }
135
136#ifdef CONFIG_X86_32
137 if (!HAVE_HWFP) {
138 memset(tsk->thread.xstate, 0, xstate_size);
139 finit_task(tsk);
140 set_stopped_child_used_math(tsk);
141 return 0;
142 }
143#endif
144
145 if (cpu_has_fxsr) {
146 struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
147
148 memset(fx, 0, xstate_size);
149 fx->cwd = 0x37f;
150 if (cpu_has_xmm)
151 fx->mxcsr = MXCSR_DEFAULT;
152 } else {
153 struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
154 memset(fp, 0, xstate_size);
155 fp->cwd = 0xffff037fu;
156 fp->swd = 0xffff0000u;
157 fp->twd = 0xffffffffu;
158 fp->fos = 0xffff0000u;
159 }
160
161
162
163 set_stopped_child_used_math(tsk);
164 return 0;
165}
166
167int fpregs_active(struct task_struct *target, const struct user_regset *regset)
168{
169 return tsk_used_math(target) ? regset->n : 0;
170}
171
172int xfpregs_active(struct task_struct *target, const struct user_regset *regset)
173{
174 return (cpu_has_fxsr && tsk_used_math(target)) ? regset->n : 0;
175}
176
177int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
178 unsigned int pos, unsigned int count,
179 void *kbuf, void __user *ubuf)
180{
181 int ret;
182
183 if (!cpu_has_fxsr)
184 return -ENODEV;
185
186 ret = init_fpu(target);
187 if (ret)
188 return ret;
189
190 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
191 &target->thread.xstate->fxsave, 0, -1);
192}
193
194int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
195 unsigned int pos, unsigned int count,
196 const void *kbuf, const void __user *ubuf)
197{
198 int ret;
199
200 if (!cpu_has_fxsr)
201 return -ENODEV;
202
203 ret = init_fpu(target);
204 if (ret)
205 return ret;
206
207 set_stopped_child_used_math(target);
208
209 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
210 &target->thread.xstate->fxsave, 0, -1);
211
212
213
214
215 target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
216
217
218
219
220
221 if (cpu_has_xsave)
222 target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
223
224 return ret;
225}
226
227#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
228
229
230
231
232
233static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
234{
235 unsigned int tmp;
236
237
238 tmp = ~twd;
239 tmp = (tmp | (tmp>>1)) & 0x5555;
240
241 tmp = (tmp | (tmp >> 1)) & 0x3333;
242 tmp = (tmp | (tmp >> 2)) & 0x0f0f;
243 tmp = (tmp | (tmp >> 4)) & 0x00ff;
244
245 return tmp;
246}
247
248#define FPREG_ADDR(f, n) ((void *)&(f)->st_space + (n) * 16);
249#define FP_EXP_TAG_VALID 0
250#define FP_EXP_TAG_ZERO 1
251#define FP_EXP_TAG_SPECIAL 2
252#define FP_EXP_TAG_EMPTY 3
253
254static inline u32 twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave)
255{
256 struct _fpxreg *st;
257 u32 tos = (fxsave->swd >> 11) & 7;
258 u32 twd = (unsigned long) fxsave->twd;
259 u32 tag;
260 u32 ret = 0xffff0000u;
261 int i;
262
263 for (i = 0; i < 8; i++, twd >>= 1) {
264 if (twd & 0x1) {
265 st = FPREG_ADDR(fxsave, (i - tos) & 7);
266
267 switch (st->exponent & 0x7fff) {
268 case 0x7fff:
269 tag = FP_EXP_TAG_SPECIAL;
270 break;
271 case 0x0000:
272 if (!st->significand[0] &&
273 !st->significand[1] &&
274 !st->significand[2] &&
275 !st->significand[3])
276 tag = FP_EXP_TAG_ZERO;
277 else
278 tag = FP_EXP_TAG_SPECIAL;
279 break;
280 default:
281 if (st->significand[3] & 0x8000)
282 tag = FP_EXP_TAG_VALID;
283 else
284 tag = FP_EXP_TAG_SPECIAL;
285 break;
286 }
287 } else {
288 tag = FP_EXP_TAG_EMPTY;
289 }
290 ret |= tag << (2 * i);
291 }
292 return ret;
293}
294
295
296
297
298
299static void
300convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
301{
302 struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
303 struct _fpreg *to = (struct _fpreg *) &env->st_space[0];
304 struct _fpxreg *from = (struct _fpxreg *) &fxsave->st_space[0];
305 int i;
306
307 env->cwd = fxsave->cwd | 0xffff0000u;
308 env->swd = fxsave->swd | 0xffff0000u;
309 env->twd = twd_fxsr_to_i387(fxsave);
310
311#ifdef CONFIG_X86_64
312 env->fip = fxsave->rip;
313 env->foo = fxsave->rdp;
314 if (tsk == current) {
315
316
317
318
319 asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos));
320 asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs));
321 } else {
322 struct pt_regs *regs = task_pt_regs(tsk);
323
324 env->fos = 0xffff0000 | tsk->thread.ds;
325 env->fcs = regs->cs;
326 }
327#else
328 env->fip = fxsave->fip;
329 env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);
330 env->foo = fxsave->foo;
331 env->fos = fxsave->fos;
332#endif
333
334 for (i = 0; i < 8; ++i)
335 memcpy(&to[i], &from[i], sizeof(to[0]));
336}
337
338static void convert_to_fxsr(struct task_struct *tsk,
339 const struct user_i387_ia32_struct *env)
340
341{
342 struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
343 struct _fpreg *from = (struct _fpreg *) &env->st_space[0];
344 struct _fpxreg *to = (struct _fpxreg *) &fxsave->st_space[0];
345 int i;
346
347 fxsave->cwd = env->cwd;
348 fxsave->swd = env->swd;
349 fxsave->twd = twd_i387_to_fxsr(env->twd);
350 fxsave->fop = (u16) ((u32) env->fcs >> 16);
351#ifdef CONFIG_X86_64
352 fxsave->rip = env->fip;
353 fxsave->rdp = env->foo;
354
355#else
356 fxsave->fip = env->fip;
357 fxsave->fcs = (env->fcs & 0xffff);
358 fxsave->foo = env->foo;
359 fxsave->fos = env->fos;
360#endif
361
362 for (i = 0; i < 8; ++i)
363 memcpy(&to[i], &from[i], sizeof(from[0]));
364}
365
366int fpregs_get(struct task_struct *target, const struct user_regset *regset,
367 unsigned int pos, unsigned int count,
368 void *kbuf, void __user *ubuf)
369{
370 struct user_i387_ia32_struct env;
371 int ret;
372
373 ret = init_fpu(target);
374 if (ret)
375 return ret;
376
377 if (!HAVE_HWFP)
378 return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf);
379
380 if (!cpu_has_fxsr) {
381 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
382 &target->thread.xstate->fsave, 0,
383 -1);
384 }
385
386 if (kbuf && pos == 0 && count == sizeof(env)) {
387 convert_from_fxsr(kbuf, target);
388 return 0;
389 }
390
391 convert_from_fxsr(&env, target);
392
393 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
394}
395
396int fpregs_set(struct task_struct *target, const struct user_regset *regset,
397 unsigned int pos, unsigned int count,
398 const void *kbuf, const void __user *ubuf)
399{
400 struct user_i387_ia32_struct env;
401 int ret;
402
403 ret = init_fpu(target);
404 if (ret)
405 return ret;
406
407 set_stopped_child_used_math(target);
408
409 if (!HAVE_HWFP)
410 return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
411
412 if (!cpu_has_fxsr) {
413 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
414 &target->thread.xstate->fsave, 0, -1);
415 }
416
417 if (pos > 0 || count < sizeof(env))
418 convert_from_fxsr(&env, target);
419
420 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
421 if (!ret)
422 convert_to_fxsr(target, &env);
423
424
425
426
427
428 if (cpu_has_xsave)
429 target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
430 return ret;
431}
432
433
434
435
436
437static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
438{
439 struct task_struct *tsk = current;
440 struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
441
442 fp->status = fp->swd;
443 if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))
444 return -1;
445 return 1;
446}
447
448static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
449{
450 struct task_struct *tsk = current;
451 struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
452 struct user_i387_ia32_struct env;
453 int err = 0;
454
455 convert_from_fxsr(&env, tsk);
456 if (__copy_to_user(buf, &env, sizeof(env)))
457 return -1;
458
459 err |= __put_user(fx->swd, &buf->status);
460 err |= __put_user(X86_FXSR_MAGIC, &buf->magic);
461 if (err)
462 return -1;
463
464 if (__copy_to_user(&buf->_fxsr_env[0], fx, xstate_size))
465 return -1;
466 return 1;
467}
468
469static int save_i387_xsave(void __user *buf)
470{
471 struct task_struct *tsk = current;
472 struct _fpstate_ia32 __user *fx = buf;
473 int err = 0;
474
475
476
477
478
479
480
481
482
483
484
485
486 tsk->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
487
488 if (save_i387_fxsave(fx) < 0)
489 return -1;
490
491 err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved_ia32,
492 sizeof(struct _fpx_sw_bytes));
493 err |= __put_user(FP_XSTATE_MAGIC2,
494 (__u32 __user *) (buf + sig_xstate_ia32_size
495 - FP_XSTATE_MAGIC2_SIZE));
496 if (err)
497 return -1;
498
499 return 1;
500}
501
502int save_i387_xstate_ia32(void __user *buf)
503{
504 struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
505 struct task_struct *tsk = current;
506
507 if (!used_math())
508 return 0;
509
510 if (!access_ok(VERIFY_WRITE, buf, sig_xstate_ia32_size))
511 return -EACCES;
512
513
514
515
516 clear_used_math();
517
518 if (!HAVE_HWFP) {
519 return fpregs_soft_get(current, NULL,
520 0, sizeof(struct user_i387_ia32_struct),
521 NULL, fp) ? -1 : 1;
522 }
523
524 unlazy_fpu(tsk);
525
526 if (cpu_has_xsave)
527 return save_i387_xsave(fp);
528 if (cpu_has_fxsr)
529 return save_i387_fxsave(fp);
530 else
531 return save_i387_fsave(fp);
532}
533
534static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
535{
536 struct task_struct *tsk = current;
537
538 return __copy_from_user(&tsk->thread.xstate->fsave, buf,
539 sizeof(struct i387_fsave_struct));
540}
541
542static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf,
543 unsigned int size)
544{
545 struct task_struct *tsk = current;
546 struct user_i387_ia32_struct env;
547 int err;
548
549 err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0],
550 size);
551
552 tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
553 if (err || __copy_from_user(&env, buf, sizeof(env)))
554 return 1;
555 convert_to_fxsr(tsk, &env);
556
557 return 0;
558}
559
560static int restore_i387_xsave(void __user *buf)
561{
562 struct _fpx_sw_bytes fx_sw_user;
563 struct _fpstate_ia32 __user *fx_user =
564 ((struct _fpstate_ia32 __user *) buf);
565 struct i387_fxsave_struct __user *fx =
566 (struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
567 struct xsave_hdr_struct *xsave_hdr =
568 ¤t->thread.xstate->xsave.xsave_hdr;
569 u64 mask;
570 int err;
571
572 if (check_for_xstate(fx, buf, &fx_sw_user))
573 goto fx_only;
574
575 mask = fx_sw_user.xstate_bv;
576
577 err = restore_i387_fxsave(buf, fx_sw_user.xstate_size);
578
579 xsave_hdr->xstate_bv &= pcntxt_mask;
580
581
582
583 xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
584
585
586
587
588
589 mask = ~(pcntxt_mask & ~mask);
590 xsave_hdr->xstate_bv &= mask;
591
592 return err;
593fx_only:
594
595
596
597
598
599 xsave_hdr->xstate_bv = XSTATE_FPSSE;
600 return restore_i387_fxsave(buf, sizeof(struct i387_fxsave_struct));
601}
602
603int restore_i387_xstate_ia32(void __user *buf)
604{
605 int err;
606 struct task_struct *tsk = current;
607 struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
608
609 if (HAVE_HWFP)
610 clear_fpu(tsk);
611
612 if (!buf) {
613 if (used_math()) {
614 clear_fpu(tsk);
615 clear_used_math();
616 }
617
618 return 0;
619 } else
620 if (!access_ok(VERIFY_READ, buf, sig_xstate_ia32_size))
621 return -EACCES;
622
623 if (!used_math()) {
624 err = init_fpu(tsk);
625 if (err)
626 return err;
627 }
628
629 if (HAVE_HWFP) {
630 if (cpu_has_xsave)
631 err = restore_i387_xsave(buf);
632 else if (cpu_has_fxsr)
633 err = restore_i387_fxsave(fp, sizeof(struct
634 i387_fxsave_struct));
635 else
636 err = restore_i387_fsave(fp);
637 } else {
638 err = fpregs_soft_set(current, NULL,
639 0, sizeof(struct user_i387_ia32_struct),
640 NULL, fp) != 0;
641 }
642 set_used_math();
643
644 return err;
645}
646
647
648
649
650
651
652
653
654int dump_fpu(struct pt_regs *regs, struct user_i387_struct *fpu)
655{
656 struct task_struct *tsk = current;
657 int fpvalid;
658
659 fpvalid = !!used_math();
660 if (fpvalid)
661 fpvalid = !fpregs_get(tsk, NULL,
662 0, sizeof(struct user_i387_ia32_struct),
663 fpu, NULL);
664
665 return fpvalid;
666}
667EXPORT_SYMBOL(dump_fpu);
668
669#endif
670