Merge branch 'master' of /usr/src/ntfs-2.6/
[linux-2.6] / arch / powerpc / kernel / process.c
1 /*
2  *  arch/ppc/kernel/process.c
3  *
4  *  Derived from "arch/i386/kernel/process.c"
5  *    Copyright (C) 1995  Linus Torvalds
6  *
7  *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
8  *  Paul Mackerras (paulus@cs.anu.edu.au)
9  *
10  *  PowerPC version
11  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
12  *
13  *  This program is free software; you can redistribute it and/or
14  *  modify it under the terms of the GNU General Public License
15  *  as published by the Free Software Foundation; either version
16  *  2 of the License, or (at your option) any later version.
17  */
18
19 #include <linux/config.h>
20 #include <linux/errno.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/smp.h>
25 #include <linux/smp_lock.h>
26 #include <linux/stddef.h>
27 #include <linux/unistd.h>
28 #include <linux/ptrace.h>
29 #include <linux/slab.h>
30 #include <linux/user.h>
31 #include <linux/elf.h>
32 #include <linux/init.h>
33 #include <linux/prctl.h>
34 #include <linux/init_task.h>
35 #include <linux/module.h>
36 #include <linux/kallsyms.h>
37 #include <linux/mqueue.h>
38 #include <linux/hardirq.h>
39 #include <linux/utsname.h>
40 #include <linux/kprobes.h>
41
42 #include <asm/pgtable.h>
43 #include <asm/uaccess.h>
44 #include <asm/system.h>
45 #include <asm/io.h>
46 #include <asm/processor.h>
47 #include <asm/mmu.h>
48 #include <asm/prom.h>
49 #ifdef CONFIG_PPC64
50 #include <asm/firmware.h>
51 #include <asm/plpar_wrappers.h>
52 #include <asm/time.h>
53 #endif
54
55 extern unsigned long _get_SP(void);
56
57 #ifndef CONFIG_SMP
58 struct task_struct *last_task_used_math = NULL;
59 struct task_struct *last_task_used_altivec = NULL;
60 struct task_struct *last_task_used_spe = NULL;
61 #endif
62
63 /*
64  * Make sure the floating-point register state in the
65  * the thread_struct is up to date for task tsk.
66  */
67 void flush_fp_to_thread(struct task_struct *tsk)
68 {
69         if (tsk->thread.regs) {
70                 /*
71                  * We need to disable preemption here because if we didn't,
72                  * another process could get scheduled after the regs->msr
73                  * test but before we have finished saving the FP registers
74                  * to the thread_struct.  That process could take over the
75                  * FPU, and then when we get scheduled again we would store
76                  * bogus values for the remaining FP registers.
77                  */
78                 preempt_disable();
79                 if (tsk->thread.regs->msr & MSR_FP) {
80 #ifdef CONFIG_SMP
81                         /*
82                          * This should only ever be called for current or
83                          * for a stopped child process.  Since we save away
84                          * the FP register state on context switch on SMP,
85                          * there is something wrong if a stopped child appears
86                          * to still have its FP state in the CPU registers.
87                          */
88                         BUG_ON(tsk != current);
89 #endif
90                         giveup_fpu(current);
91                 }
92                 preempt_enable();
93         }
94 }
95
96 void enable_kernel_fp(void)
97 {
98         WARN_ON(preemptible());
99
100 #ifdef CONFIG_SMP
101         if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
102                 giveup_fpu(current);
103         else
104                 giveup_fpu(NULL);       /* just enables FP for kernel */
105 #else
106         giveup_fpu(last_task_used_math);
107 #endif /* CONFIG_SMP */
108 }
109 EXPORT_SYMBOL(enable_kernel_fp);
110
111 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
112 {
113         if (!tsk->thread.regs)
114                 return 0;
115         flush_fp_to_thread(current);
116
117         memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
118
119         return 1;
120 }
121
122 #ifdef CONFIG_ALTIVEC
123 void enable_kernel_altivec(void)
124 {
125         WARN_ON(preemptible());
126
127 #ifdef CONFIG_SMP
128         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
129                 giveup_altivec(current);
130         else
131                 giveup_altivec(NULL);   /* just enable AltiVec for kernel - force */
132 #else
133         giveup_altivec(last_task_used_altivec);
134 #endif /* CONFIG_SMP */
135 }
136 EXPORT_SYMBOL(enable_kernel_altivec);
137
138 /*
139  * Make sure the VMX/Altivec register state in the
140  * the thread_struct is up to date for task tsk.
141  */
142 void flush_altivec_to_thread(struct task_struct *tsk)
143 {
144         if (tsk->thread.regs) {
145                 preempt_disable();
146                 if (tsk->thread.regs->msr & MSR_VEC) {
147 #ifdef CONFIG_SMP
148                         BUG_ON(tsk != current);
149 #endif
150                         giveup_altivec(current);
151                 }
152                 preempt_enable();
153         }
154 }
155
156 int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
157 {
158         flush_altivec_to_thread(current);
159         memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
160         return 1;
161 }
162 #endif /* CONFIG_ALTIVEC */
163
164 #ifdef CONFIG_SPE
165
166 void enable_kernel_spe(void)
167 {
168         WARN_ON(preemptible());
169
170 #ifdef CONFIG_SMP
171         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
172                 giveup_spe(current);
173         else
174                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
175 #else
176         giveup_spe(last_task_used_spe);
177 #endif /* __SMP __ */
178 }
179 EXPORT_SYMBOL(enable_kernel_spe);
180
181 void flush_spe_to_thread(struct task_struct *tsk)
182 {
183         if (tsk->thread.regs) {
184                 preempt_disable();
185                 if (tsk->thread.regs->msr & MSR_SPE) {
186 #ifdef CONFIG_SMP
187                         BUG_ON(tsk != current);
188 #endif
189                         giveup_spe(current);
190                 }
191                 preempt_enable();
192         }
193 }
194
195 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
196 {
197         flush_spe_to_thread(current);
198         /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
199         memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
200         return 1;
201 }
202 #endif /* CONFIG_SPE */
203
204 static void set_dabr_spr(unsigned long val)
205 {
206         mtspr(SPRN_DABR, val);
207 }
208
209 int set_dabr(unsigned long dabr)
210 {
211         int ret = 0;
212
213 #ifdef CONFIG_PPC64
214         if (firmware_has_feature(FW_FEATURE_XDABR)) {
215                 /* We want to catch accesses from kernel and userspace */
216                 unsigned long flags = H_DABRX_KERNEL|H_DABRX_USER;
217                 ret = plpar_set_xdabr(dabr, flags);
218         } else if (firmware_has_feature(FW_FEATURE_DABR)) {
219                 ret = plpar_set_dabr(dabr);
220         } else
221 #endif
222                 set_dabr_spr(dabr);
223
224         return ret;
225 }
226
227 #ifdef CONFIG_PPC64
228 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
229 static DEFINE_PER_CPU(unsigned long, current_dabr);
230 #endif
231
232 struct task_struct *__switch_to(struct task_struct *prev,
233         struct task_struct *new)
234 {
235         struct thread_struct *new_thread, *old_thread;
236         unsigned long flags;
237         struct task_struct *last;
238
239 #ifdef CONFIG_SMP
240         /* avoid complexity of lazy save/restore of fpu
241          * by just saving it every time we switch out if
242          * this task used the fpu during the last quantum.
243          *
244          * If it tries to use the fpu again, it'll trap and
245          * reload its fp regs.  So we don't have to do a restore
246          * every switch, just a save.
247          *  -- Cort
248          */
249         if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
250                 giveup_fpu(prev);
251 #ifdef CONFIG_ALTIVEC
252         /*
253          * If the previous thread used altivec in the last quantum
254          * (thus changing altivec regs) then save them.
255          * We used to check the VRSAVE register but not all apps
256          * set it, so we don't rely on it now (and in fact we need
257          * to save & restore VSCR even if VRSAVE == 0).  -- paulus
258          *
259          * On SMP we always save/restore altivec regs just to avoid the
260          * complexity of changing processors.
261          *  -- Cort
262          */
263         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
264                 giveup_altivec(prev);
265 #endif /* CONFIG_ALTIVEC */
266 #ifdef CONFIG_SPE
267         /*
268          * If the previous thread used spe in the last quantum
269          * (thus changing spe regs) then save them.
270          *
271          * On SMP we always save/restore spe regs just to avoid the
272          * complexity of changing processors.
273          */
274         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
275                 giveup_spe(prev);
276 #endif /* CONFIG_SPE */
277
278 #else  /* CONFIG_SMP */
279 #ifdef CONFIG_ALTIVEC
280         /* Avoid the trap.  On smp this this never happens since
281          * we don't set last_task_used_altivec -- Cort
282          */
283         if (new->thread.regs && last_task_used_altivec == new)
284                 new->thread.regs->msr |= MSR_VEC;
285 #endif /* CONFIG_ALTIVEC */
286 #ifdef CONFIG_SPE
287         /* Avoid the trap.  On smp this this never happens since
288          * we don't set last_task_used_spe
289          */
290         if (new->thread.regs && last_task_used_spe == new)
291                 new->thread.regs->msr |= MSR_SPE;
292 #endif /* CONFIG_SPE */
293
294 #endif /* CONFIG_SMP */
295
296 #ifdef CONFIG_PPC64     /* for now */
297         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
298                 set_dabr(new->thread.dabr);
299                 __get_cpu_var(current_dabr) = new->thread.dabr;
300         }
301
302         flush_tlb_pending();
303 #endif
304
305         new_thread = &new->thread;
306         old_thread = &current->thread;
307
308 #ifdef CONFIG_PPC64
309         /*
310          * Collect processor utilization data per process
311          */
312         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
313                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
314                 long unsigned start_tb, current_tb;
315                 start_tb = old_thread->start_tb;
316                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
317                 old_thread->accum_tb += (current_tb - start_tb);
318                 new_thread->start_tb = current_tb;
319         }
320 #endif
321
322         local_irq_save(flags);
323         last = _switch(old_thread, new_thread);
324
325         local_irq_restore(flags);
326
327         return last;
328 }
329
330 static int instructions_to_print = 16;
331
332 #ifdef CONFIG_PPC64
333 #define BAD_PC(pc)      ((REGION_ID(pc) != KERNEL_REGION_ID) && \
334                          (REGION_ID(pc) != VMALLOC_REGION_ID))
335 #else
336 #define BAD_PC(pc)      ((pc) < KERNELBASE)
337 #endif
338
339 static void show_instructions(struct pt_regs *regs)
340 {
341         int i;
342         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
343                         sizeof(int));
344
345         printk("Instruction dump:");
346
347         for (i = 0; i < instructions_to_print; i++) {
348                 int instr;
349
350                 if (!(i % 8))
351                         printk("\n");
352
353                 if (BAD_PC(pc) || __get_user(instr, (unsigned int *)pc)) {
354                         printk("XXXXXXXX ");
355                 } else {
356                         if (regs->nip == pc)
357                                 printk("<%08x> ", instr);
358                         else
359                                 printk("%08x ", instr);
360                 }
361
362                 pc += sizeof(int);
363         }
364
365         printk("\n");
366 }
367
368 static struct regbit {
369         unsigned long bit;
370         const char *name;
371 } msr_bits[] = {
372         {MSR_EE,        "EE"},
373         {MSR_PR,        "PR"},
374         {MSR_FP,        "FP"},
375         {MSR_ME,        "ME"},
376         {MSR_IR,        "IR"},
377         {MSR_DR,        "DR"},
378         {0,             NULL}
379 };
380
381 static void printbits(unsigned long val, struct regbit *bits)
382 {
383         const char *sep = "";
384
385         printk("<");
386         for (; bits->bit; ++bits)
387                 if (val & bits->bit) {
388                         printk("%s%s", sep, bits->name);
389                         sep = ",";
390                 }
391         printk(">");
392 }
393
394 #ifdef CONFIG_PPC64
395 #define REG             "%016lX"
396 #define REGS_PER_LINE   4
397 #define LAST_VOLATILE   13
398 #else
399 #define REG             "%08lX"
400 #define REGS_PER_LINE   8
401 #define LAST_VOLATILE   12
402 #endif
403
404 void show_regs(struct pt_regs * regs)
405 {
406         int i, trap;
407
408         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
409                regs->nip, regs->link, regs->ctr);
410         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
411                regs, regs->trap, print_tainted(), system_utsname.release);
412         printk("MSR: "REG" ", regs->msr);
413         printbits(regs->msr, msr_bits);
414         printk("  CR: %08lX  XER: %08lX\n", regs->ccr, regs->xer);
415         trap = TRAP(regs);
416         if (trap == 0x300 || trap == 0x600)
417                 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
418         printk("TASK = %p[%d] '%s' THREAD: %p",
419                current, current->pid, current->comm, current->thread_info);
420
421 #ifdef CONFIG_SMP
422         printk(" CPU: %d", smp_processor_id());
423 #endif /* CONFIG_SMP */
424
425         for (i = 0;  i < 32;  i++) {
426                 if ((i % REGS_PER_LINE) == 0)
427                         printk("\n" KERN_INFO "GPR%02d: ", i);
428                 printk(REG " ", regs->gpr[i]);
429                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
430                         break;
431         }
432         printk("\n");
433 #ifdef CONFIG_KALLSYMS
434         /*
435          * Lookup NIP late so we have the best change of getting the
436          * above info out without failing
437          */
438         printk("NIP ["REG"] ", regs->nip);
439         print_symbol("%s\n", regs->nip);
440         printk("LR ["REG"] ", regs->link);
441         print_symbol("%s\n", regs->link);
442 #endif
443         show_stack(current, (unsigned long *) regs->gpr[1]);
444         if (!user_mode(regs))
445                 show_instructions(regs);
446 }
447
448 void exit_thread(void)
449 {
450         kprobe_flush_task(current);
451
452 #ifndef CONFIG_SMP
453         if (last_task_used_math == current)
454                 last_task_used_math = NULL;
455 #ifdef CONFIG_ALTIVEC
456         if (last_task_used_altivec == current)
457                 last_task_used_altivec = NULL;
458 #endif /* CONFIG_ALTIVEC */
459 #ifdef CONFIG_SPE
460         if (last_task_used_spe == current)
461                 last_task_used_spe = NULL;
462 #endif
463 #endif /* CONFIG_SMP */
464 }
465
466 void flush_thread(void)
467 {
468 #ifdef CONFIG_PPC64
469         struct thread_info *t = current_thread_info();
470
471         if (t->flags & _TIF_ABI_PENDING)
472                 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
473 #endif
474         kprobe_flush_task(current);
475
476 #ifndef CONFIG_SMP
477         if (last_task_used_math == current)
478                 last_task_used_math = NULL;
479 #ifdef CONFIG_ALTIVEC
480         if (last_task_used_altivec == current)
481                 last_task_used_altivec = NULL;
482 #endif /* CONFIG_ALTIVEC */
483 #ifdef CONFIG_SPE
484         if (last_task_used_spe == current)
485                 last_task_used_spe = NULL;
486 #endif
487 #endif /* CONFIG_SMP */
488
489 #ifdef CONFIG_PPC64     /* for now */
490         if (current->thread.dabr) {
491                 current->thread.dabr = 0;
492                 set_dabr(0);
493         }
494 #endif
495 }
496
497 void
498 release_thread(struct task_struct *t)
499 {
500 }
501
502 /*
503  * This gets called before we allocate a new thread and copy
504  * the current task into it.
505  */
506 void prepare_to_copy(struct task_struct *tsk)
507 {
508         flush_fp_to_thread(current);
509         flush_altivec_to_thread(current);
510         flush_spe_to_thread(current);
511 }
512
513 /*
514  * Copy a thread..
515  */
516 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
517                 unsigned long unused, struct task_struct *p,
518                 struct pt_regs *regs)
519 {
520         struct pt_regs *childregs, *kregs;
521         extern void ret_from_fork(void);
522         unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
523
524         CHECK_FULL_REGS(regs);
525         /* Copy registers */
526         sp -= sizeof(struct pt_regs);
527         childregs = (struct pt_regs *) sp;
528         *childregs = *regs;
529         if ((childregs->msr & MSR_PR) == 0) {
530                 /* for kernel thread, set `current' and stackptr in new task */
531                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
532 #ifdef CONFIG_PPC32
533                 childregs->gpr[2] = (unsigned long) p;
534 #else
535                 clear_ti_thread_flag(p->thread_info, TIF_32BIT);
536 #endif
537                 p->thread.regs = NULL;  /* no user register state */
538         } else {
539                 childregs->gpr[1] = usp;
540                 p->thread.regs = childregs;
541                 if (clone_flags & CLONE_SETTLS) {
542 #ifdef CONFIG_PPC64
543                         if (!test_thread_flag(TIF_32BIT))
544                                 childregs->gpr[13] = childregs->gpr[6];
545                         else
546 #endif
547                                 childregs->gpr[2] = childregs->gpr[6];
548                 }
549         }
550         childregs->gpr[3] = 0;  /* Result from fork() */
551         sp -= STACK_FRAME_OVERHEAD;
552
553         /*
554          * The way this works is that at some point in the future
555          * some task will call _switch to switch to the new task.
556          * That will pop off the stack frame created below and start
557          * the new task running at ret_from_fork.  The new task will
558          * do some house keeping and then return from the fork or clone
559          * system call, using the stack frame created above.
560          */
561         sp -= sizeof(struct pt_regs);
562         kregs = (struct pt_regs *) sp;
563         sp -= STACK_FRAME_OVERHEAD;
564         p->thread.ksp = sp;
565
566 #ifdef CONFIG_PPC64
567         if (cpu_has_feature(CPU_FTR_SLB)) {
568                 unsigned long sp_vsid = get_kernel_vsid(sp);
569
570                 sp_vsid <<= SLB_VSID_SHIFT;
571                 sp_vsid |= SLB_VSID_KERNEL;
572                 if (cpu_has_feature(CPU_FTR_16M_PAGE))
573                         sp_vsid |= SLB_VSID_L;
574
575                 p->thread.ksp_vsid = sp_vsid;
576         }
577
578         /*
579          * The PPC64 ABI makes use of a TOC to contain function 
580          * pointers.  The function (ret_from_except) is actually a pointer
581          * to the TOC entry.  The first entry is a pointer to the actual
582          * function.
583          */
584         kregs->nip = *((unsigned long *)ret_from_fork);
585 #else
586         kregs->nip = (unsigned long)ret_from_fork;
587         p->thread.last_syscall = -1;
588 #endif
589
590         return 0;
591 }
592
593 /*
594  * Set up a thread for executing a new program
595  */
596 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
597 {
598 #ifdef CONFIG_PPC64
599         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
600 #endif
601
602         set_fs(USER_DS);
603
604         /*
605          * If we exec out of a kernel thread then thread.regs will not be
606          * set.  Do it now.
607          */
608         if (!current->thread.regs) {
609                 unsigned long childregs = (unsigned long)current->thread_info +
610                                                 THREAD_SIZE;
611                 childregs -= sizeof(struct pt_regs);
612                 current->thread.regs = (struct pt_regs *)childregs;
613         }
614
615         memset(regs->gpr, 0, sizeof(regs->gpr));
616         regs->ctr = 0;
617         regs->link = 0;
618         regs->xer = 0;
619         regs->ccr = 0;
620         regs->gpr[1] = sp;
621
622 #ifdef CONFIG_PPC32
623         regs->mq = 0;
624         regs->nip = start;
625         regs->msr = MSR_USER;
626 #else
627         if (!test_thread_flag(TIF_32BIT)) {
628                 unsigned long entry, toc;
629
630                 /* start is a relocated pointer to the function descriptor for
631                  * the elf _start routine.  The first entry in the function
632                  * descriptor is the entry address of _start and the second
633                  * entry is the TOC value we need to use.
634                  */
635                 __get_user(entry, (unsigned long __user *)start);
636                 __get_user(toc, (unsigned long __user *)start+1);
637
638                 /* Check whether the e_entry function descriptor entries
639                  * need to be relocated before we can use them.
640                  */
641                 if (load_addr != 0) {
642                         entry += load_addr;
643                         toc   += load_addr;
644                 }
645                 regs->nip = entry;
646                 regs->gpr[2] = toc;
647                 regs->msr = MSR_USER64;
648         } else {
649                 regs->nip = start;
650                 regs->gpr[2] = 0;
651                 regs->msr = MSR_USER32;
652         }
653 #endif
654
655 #ifndef CONFIG_SMP
656         if (last_task_used_math == current)
657                 last_task_used_math = NULL;
658 #ifdef CONFIG_ALTIVEC
659         if (last_task_used_altivec == current)
660                 last_task_used_altivec = NULL;
661 #endif
662 #ifdef CONFIG_SPE
663         if (last_task_used_spe == current)
664                 last_task_used_spe = NULL;
665 #endif
666 #endif /* CONFIG_SMP */
667         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
668         current->thread.fpscr.val = 0;
669 #ifdef CONFIG_ALTIVEC
670         memset(current->thread.vr, 0, sizeof(current->thread.vr));
671         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
672         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
673         current->thread.vrsave = 0;
674         current->thread.used_vr = 0;
675 #endif /* CONFIG_ALTIVEC */
676 #ifdef CONFIG_SPE
677         memset(current->thread.evr, 0, sizeof(current->thread.evr));
678         current->thread.acc = 0;
679         current->thread.spefscr = 0;
680         current->thread.used_spe = 0;
681 #endif /* CONFIG_SPE */
682 }
683
684 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
685                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
686
687 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
688 {
689         struct pt_regs *regs = tsk->thread.regs;
690
691         /* This is a bit hairy.  If we are an SPE enabled  processor
692          * (have embedded fp) we store the IEEE exception enable flags in
693          * fpexc_mode.  fpexc_mode is also used for setting FP exception
694          * mode (asyn, precise, disabled) for 'Classic' FP. */
695         if (val & PR_FP_EXC_SW_ENABLE) {
696 #ifdef CONFIG_SPE
697                 tsk->thread.fpexc_mode = val &
698                         (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
699                 return 0;
700 #else
701                 return -EINVAL;
702 #endif
703         }
704
705         /* on a CONFIG_SPE this does not hurt us.  The bits that
706          * __pack_fe01 use do not overlap with bits used for
707          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
708          * on CONFIG_SPE implementations are reserved so writing to
709          * them does not change anything */
710         if (val > PR_FP_EXC_PRECISE)
711                 return -EINVAL;
712         tsk->thread.fpexc_mode = __pack_fe01(val);
713         if (regs != NULL && (regs->msr & MSR_FP) != 0)
714                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
715                         | tsk->thread.fpexc_mode;
716         return 0;
717 }
718
719 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
720 {
721         unsigned int val;
722
723         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
724 #ifdef CONFIG_SPE
725                 val = tsk->thread.fpexc_mode;
726 #else
727                 return -EINVAL;
728 #endif
729         else
730                 val = __unpack_fe01(tsk->thread.fpexc_mode);
731         return put_user(val, (unsigned int __user *) adr);
732 }
733
734 #define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
735
736 int sys_clone(unsigned long clone_flags, unsigned long usp,
737               int __user *parent_tidp, void __user *child_threadptr,
738               int __user *child_tidp, int p6,
739               struct pt_regs *regs)
740 {
741         CHECK_FULL_REGS(regs);
742         if (usp == 0)
743                 usp = regs->gpr[1];     /* stack pointer for child */
744 #ifdef CONFIG_PPC64
745         if (test_thread_flag(TIF_32BIT)) {
746                 parent_tidp = TRUNC_PTR(parent_tidp);
747                 child_tidp = TRUNC_PTR(child_tidp);
748         }
749 #endif
750         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
751 }
752
753 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
754              unsigned long p4, unsigned long p5, unsigned long p6,
755              struct pt_regs *regs)
756 {
757         CHECK_FULL_REGS(regs);
758         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
759 }
760
761 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
762               unsigned long p4, unsigned long p5, unsigned long p6,
763               struct pt_regs *regs)
764 {
765         CHECK_FULL_REGS(regs);
766         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
767                         regs, 0, NULL, NULL);
768 }
769
770 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
771                unsigned long a3, unsigned long a4, unsigned long a5,
772                struct pt_regs *regs)
773 {
774         int error;
775         char *filename;
776
777         filename = getname((char __user *) a0);
778         error = PTR_ERR(filename);
779         if (IS_ERR(filename))
780                 goto out;
781         flush_fp_to_thread(current);
782         flush_altivec_to_thread(current);
783         flush_spe_to_thread(current);
784         error = do_execve(filename, (char __user * __user *) a1,
785                           (char __user * __user *) a2, regs);
786         if (error == 0) {
787                 task_lock(current);
788                 current->ptrace &= ~PT_DTRACE;
789                 task_unlock(current);
790         }
791         putname(filename);
792 out:
793         return error;
794 }
795
796 static int validate_sp(unsigned long sp, struct task_struct *p,
797                        unsigned long nbytes)
798 {
799         unsigned long stack_page = (unsigned long)p->thread_info;
800
801         if (sp >= stack_page + sizeof(struct thread_struct)
802             && sp <= stack_page + THREAD_SIZE - nbytes)
803                 return 1;
804
805 #ifdef CONFIG_IRQSTACKS
806         stack_page = (unsigned long) hardirq_ctx[task_cpu(p)];
807         if (sp >= stack_page + sizeof(struct thread_struct)
808             && sp <= stack_page + THREAD_SIZE - nbytes)
809                 return 1;
810
811         stack_page = (unsigned long) softirq_ctx[task_cpu(p)];
812         if (sp >= stack_page + sizeof(struct thread_struct)
813             && sp <= stack_page + THREAD_SIZE - nbytes)
814                 return 1;
815 #endif
816
817         return 0;
818 }
819
820 #ifdef CONFIG_PPC64
821 #define MIN_STACK_FRAME 112     /* same as STACK_FRAME_OVERHEAD, in fact */
822 #define FRAME_LR_SAVE   2
823 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
824 #define REGS_MARKER     0x7265677368657265ul
825 #define FRAME_MARKER    12
826 #else
827 #define MIN_STACK_FRAME 16
828 #define FRAME_LR_SAVE   1
829 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
830 #define REGS_MARKER     0x72656773ul
831 #define FRAME_MARKER    2
832 #endif
833
834 unsigned long get_wchan(struct task_struct *p)
835 {
836         unsigned long ip, sp;
837         int count = 0;
838
839         if (!p || p == current || p->state == TASK_RUNNING)
840                 return 0;
841
842         sp = p->thread.ksp;
843         if (!validate_sp(sp, p, MIN_STACK_FRAME))
844                 return 0;
845
846         do {
847                 sp = *(unsigned long *)sp;
848                 if (!validate_sp(sp, p, MIN_STACK_FRAME))
849                         return 0;
850                 if (count > 0) {
851                         ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
852                         if (!in_sched_functions(ip))
853                                 return ip;
854                 }
855         } while (count++ < 16);
856         return 0;
857 }
858 EXPORT_SYMBOL(get_wchan);
859
860 static int kstack_depth_to_print = 64;
861
862 void show_stack(struct task_struct *tsk, unsigned long *stack)
863 {
864         unsigned long sp, ip, lr, newsp;
865         int count = 0;
866         int firstframe = 1;
867
868         sp = (unsigned long) stack;
869         if (tsk == NULL)
870                 tsk = current;
871         if (sp == 0) {
872                 if (tsk == current)
873                         asm("mr %0,1" : "=r" (sp));
874                 else
875                         sp = tsk->thread.ksp;
876         }
877
878         lr = 0;
879         printk("Call Trace:\n");
880         do {
881                 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
882                         return;
883
884                 stack = (unsigned long *) sp;
885                 newsp = stack[0];
886                 ip = stack[FRAME_LR_SAVE];
887                 if (!firstframe || ip != lr) {
888                         printk("["REG"] ["REG"] ", sp, ip);
889                         print_symbol("%s", ip);
890                         if (firstframe)
891                                 printk(" (unreliable)");
892                         printk("\n");
893                 }
894                 firstframe = 0;
895
896                 /*
897                  * See if this is an exception frame.
898                  * We look for the "regshere" marker in the current frame.
899                  */
900                 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
901                     && stack[FRAME_MARKER] == REGS_MARKER) {
902                         struct pt_regs *regs = (struct pt_regs *)
903                                 (sp + STACK_FRAME_OVERHEAD);
904                         printk("--- Exception: %lx", regs->trap);
905                         print_symbol(" at %s\n", regs->nip);
906                         lr = regs->link;
907                         print_symbol("    LR = %s\n", lr);
908                         firstframe = 1;
909                 }
910
911                 sp = newsp;
912         } while (count++ < kstack_depth_to_print);
913 }
914
915 void dump_stack(void)
916 {
917         show_stack(current, NULL);
918 }
919 EXPORT_SYMBOL(dump_stack);