Merge ../linux-2.6
[linux-3.10.git] / 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 #include <asm/machdep.h>
50 #ifdef CONFIG_PPC64
51 #include <asm/firmware.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 int set_dabr(unsigned long dabr)
205 {
206         if (ppc_md.set_dabr)
207                 return ppc_md.set_dabr(dabr);
208
209         mtspr(SPRN_DABR, dabr);
210         return 0;
211 }
212
213 #ifdef CONFIG_PPC64
214 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
215 static DEFINE_PER_CPU(unsigned long, current_dabr);
216 #endif
217
218 struct task_struct *__switch_to(struct task_struct *prev,
219         struct task_struct *new)
220 {
221         struct thread_struct *new_thread, *old_thread;
222         unsigned long flags;
223         struct task_struct *last;
224
225 #ifdef CONFIG_SMP
226         /* avoid complexity of lazy save/restore of fpu
227          * by just saving it every time we switch out if
228          * this task used the fpu during the last quantum.
229          *
230          * If it tries to use the fpu again, it'll trap and
231          * reload its fp regs.  So we don't have to do a restore
232          * every switch, just a save.
233          *  -- Cort
234          */
235         if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
236                 giveup_fpu(prev);
237 #ifdef CONFIG_ALTIVEC
238         /*
239          * If the previous thread used altivec in the last quantum
240          * (thus changing altivec regs) then save them.
241          * We used to check the VRSAVE register but not all apps
242          * set it, so we don't rely on it now (and in fact we need
243          * to save & restore VSCR even if VRSAVE == 0).  -- paulus
244          *
245          * On SMP we always save/restore altivec regs just to avoid the
246          * complexity of changing processors.
247          *  -- Cort
248          */
249         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
250                 giveup_altivec(prev);
251 #endif /* CONFIG_ALTIVEC */
252 #ifdef CONFIG_SPE
253         /*
254          * If the previous thread used spe in the last quantum
255          * (thus changing spe regs) then save them.
256          *
257          * On SMP we always save/restore spe regs just to avoid the
258          * complexity of changing processors.
259          */
260         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
261                 giveup_spe(prev);
262 #endif /* CONFIG_SPE */
263
264 #else  /* CONFIG_SMP */
265 #ifdef CONFIG_ALTIVEC
266         /* Avoid the trap.  On smp this this never happens since
267          * we don't set last_task_used_altivec -- Cort
268          */
269         if (new->thread.regs && last_task_used_altivec == new)
270                 new->thread.regs->msr |= MSR_VEC;
271 #endif /* CONFIG_ALTIVEC */
272 #ifdef CONFIG_SPE
273         /* Avoid the trap.  On smp this this never happens since
274          * we don't set last_task_used_spe
275          */
276         if (new->thread.regs && last_task_used_spe == new)
277                 new->thread.regs->msr |= MSR_SPE;
278 #endif /* CONFIG_SPE */
279
280 #endif /* CONFIG_SMP */
281
282 #ifdef CONFIG_PPC64     /* for now */
283         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
284                 set_dabr(new->thread.dabr);
285                 __get_cpu_var(current_dabr) = new->thread.dabr;
286         }
287
288         flush_tlb_pending();
289 #endif
290
291         new_thread = &new->thread;
292         old_thread = &current->thread;
293
294 #ifdef CONFIG_PPC64
295         /*
296          * Collect processor utilization data per process
297          */
298         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
299                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
300                 long unsigned start_tb, current_tb;
301                 start_tb = old_thread->start_tb;
302                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
303                 old_thread->accum_tb += (current_tb - start_tb);
304                 new_thread->start_tb = current_tb;
305         }
306 #endif
307
308         local_irq_save(flags);
309         last = _switch(old_thread, new_thread);
310
311         local_irq_restore(flags);
312
313         return last;
314 }
315
316 static int instructions_to_print = 16;
317
318 #ifdef CONFIG_PPC64
319 #define BAD_PC(pc)      ((REGION_ID(pc) != KERNEL_REGION_ID) && \
320                          (REGION_ID(pc) != VMALLOC_REGION_ID))
321 #else
322 #define BAD_PC(pc)      ((pc) < KERNELBASE)
323 #endif
324
325 static void show_instructions(struct pt_regs *regs)
326 {
327         int i;
328         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
329                         sizeof(int));
330
331         printk("Instruction dump:");
332
333         for (i = 0; i < instructions_to_print; i++) {
334                 int instr;
335
336                 if (!(i % 8))
337                         printk("\n");
338
339                 if (BAD_PC(pc) || __get_user(instr, (unsigned int *)pc)) {
340                         printk("XXXXXXXX ");
341                 } else {
342                         if (regs->nip == pc)
343                                 printk("<%08x> ", instr);
344                         else
345                                 printk("%08x ", instr);
346                 }
347
348                 pc += sizeof(int);
349         }
350
351         printk("\n");
352 }
353
354 static struct regbit {
355         unsigned long bit;
356         const char *name;
357 } msr_bits[] = {
358         {MSR_EE,        "EE"},
359         {MSR_PR,        "PR"},
360         {MSR_FP,        "FP"},
361         {MSR_ME,        "ME"},
362         {MSR_IR,        "IR"},
363         {MSR_DR,        "DR"},
364         {0,             NULL}
365 };
366
367 static void printbits(unsigned long val, struct regbit *bits)
368 {
369         const char *sep = "";
370
371         printk("<");
372         for (; bits->bit; ++bits)
373                 if (val & bits->bit) {
374                         printk("%s%s", sep, bits->name);
375                         sep = ",";
376                 }
377         printk(">");
378 }
379
380 #ifdef CONFIG_PPC64
381 #define REG             "%016lX"
382 #define REGS_PER_LINE   4
383 #define LAST_VOLATILE   13
384 #else
385 #define REG             "%08lX"
386 #define REGS_PER_LINE   8
387 #define LAST_VOLATILE   12
388 #endif
389
390 void show_regs(struct pt_regs * regs)
391 {
392         int i, trap;
393
394         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
395                regs->nip, regs->link, regs->ctr);
396         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
397                regs, regs->trap, print_tainted(), system_utsname.release);
398         printk("MSR: "REG" ", regs->msr);
399         printbits(regs->msr, msr_bits);
400         printk("  CR: %08lX  XER: %08lX\n", regs->ccr, regs->xer);
401         trap = TRAP(regs);
402         if (trap == 0x300 || trap == 0x600)
403                 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
404         printk("TASK = %p[%d] '%s' THREAD: %p",
405                current, current->pid, current->comm, current->thread_info);
406
407 #ifdef CONFIG_SMP
408         printk(" CPU: %d", smp_processor_id());
409 #endif /* CONFIG_SMP */
410
411         for (i = 0;  i < 32;  i++) {
412                 if ((i % REGS_PER_LINE) == 0)
413                         printk("\n" KERN_INFO "GPR%02d: ", i);
414                 printk(REG " ", regs->gpr[i]);
415                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
416                         break;
417         }
418         printk("\n");
419 #ifdef CONFIG_KALLSYMS
420         /*
421          * Lookup NIP late so we have the best change of getting the
422          * above info out without failing
423          */
424         printk("NIP ["REG"] ", regs->nip);
425         print_symbol("%s\n", regs->nip);
426         printk("LR ["REG"] ", regs->link);
427         print_symbol("%s\n", regs->link);
428 #endif
429         show_stack(current, (unsigned long *) regs->gpr[1]);
430         if (!user_mode(regs))
431                 show_instructions(regs);
432 }
433
434 void exit_thread(void)
435 {
436         kprobe_flush_task(current);
437
438 #ifndef CONFIG_SMP
439         if (last_task_used_math == current)
440                 last_task_used_math = NULL;
441 #ifdef CONFIG_ALTIVEC
442         if (last_task_used_altivec == current)
443                 last_task_used_altivec = NULL;
444 #endif /* CONFIG_ALTIVEC */
445 #ifdef CONFIG_SPE
446         if (last_task_used_spe == current)
447                 last_task_used_spe = NULL;
448 #endif
449 #endif /* CONFIG_SMP */
450 }
451
452 void flush_thread(void)
453 {
454 #ifdef CONFIG_PPC64
455         struct thread_info *t = current_thread_info();
456
457         if (t->flags & _TIF_ABI_PENDING)
458                 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
459 #endif
460         kprobe_flush_task(current);
461
462 #ifndef CONFIG_SMP
463         if (last_task_used_math == current)
464                 last_task_used_math = NULL;
465 #ifdef CONFIG_ALTIVEC
466         if (last_task_used_altivec == current)
467                 last_task_used_altivec = NULL;
468 #endif /* CONFIG_ALTIVEC */
469 #ifdef CONFIG_SPE
470         if (last_task_used_spe == current)
471                 last_task_used_spe = NULL;
472 #endif
473 #endif /* CONFIG_SMP */
474
475 #ifdef CONFIG_PPC64     /* for now */
476         if (current->thread.dabr) {
477                 current->thread.dabr = 0;
478                 set_dabr(0);
479         }
480 #endif
481 }
482
483 void
484 release_thread(struct task_struct *t)
485 {
486 }
487
488 /*
489  * This gets called before we allocate a new thread and copy
490  * the current task into it.
491  */
492 void prepare_to_copy(struct task_struct *tsk)
493 {
494         flush_fp_to_thread(current);
495         flush_altivec_to_thread(current);
496         flush_spe_to_thread(current);
497 }
498
499 /*
500  * Copy a thread..
501  */
502 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
503                 unsigned long unused, struct task_struct *p,
504                 struct pt_regs *regs)
505 {
506         struct pt_regs *childregs, *kregs;
507         extern void ret_from_fork(void);
508         unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
509
510         CHECK_FULL_REGS(regs);
511         /* Copy registers */
512         sp -= sizeof(struct pt_regs);
513         childregs = (struct pt_regs *) sp;
514         *childregs = *regs;
515         if ((childregs->msr & MSR_PR) == 0) {
516                 /* for kernel thread, set `current' and stackptr in new task */
517                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
518 #ifdef CONFIG_PPC32
519                 childregs->gpr[2] = (unsigned long) p;
520 #else
521                 clear_ti_thread_flag(p->thread_info, TIF_32BIT);
522 #endif
523                 p->thread.regs = NULL;  /* no user register state */
524         } else {
525                 childregs->gpr[1] = usp;
526                 p->thread.regs = childregs;
527                 if (clone_flags & CLONE_SETTLS) {
528 #ifdef CONFIG_PPC64
529                         if (!test_thread_flag(TIF_32BIT))
530                                 childregs->gpr[13] = childregs->gpr[6];
531                         else
532 #endif
533                                 childregs->gpr[2] = childregs->gpr[6];
534                 }
535         }
536         childregs->gpr[3] = 0;  /* Result from fork() */
537         sp -= STACK_FRAME_OVERHEAD;
538
539         /*
540          * The way this works is that at some point in the future
541          * some task will call _switch to switch to the new task.
542          * That will pop off the stack frame created below and start
543          * the new task running at ret_from_fork.  The new task will
544          * do some house keeping and then return from the fork or clone
545          * system call, using the stack frame created above.
546          */
547         sp -= sizeof(struct pt_regs);
548         kregs = (struct pt_regs *) sp;
549         sp -= STACK_FRAME_OVERHEAD;
550         p->thread.ksp = sp;
551
552 #ifdef CONFIG_PPC64
553         if (cpu_has_feature(CPU_FTR_SLB)) {
554                 unsigned long sp_vsid = get_kernel_vsid(sp);
555                 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
556
557                 sp_vsid <<= SLB_VSID_SHIFT;
558                 sp_vsid |= SLB_VSID_KERNEL | llp;
559                 p->thread.ksp_vsid = sp_vsid;
560         }
561
562         /*
563          * The PPC64 ABI makes use of a TOC to contain function 
564          * pointers.  The function (ret_from_except) is actually a pointer
565          * to the TOC entry.  The first entry is a pointer to the actual
566          * function.
567          */
568         kregs->nip = *((unsigned long *)ret_from_fork);
569 #else
570         kregs->nip = (unsigned long)ret_from_fork;
571         p->thread.last_syscall = -1;
572 #endif
573
574         return 0;
575 }
576
577 /*
578  * Set up a thread for executing a new program
579  */
580 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
581 {
582 #ifdef CONFIG_PPC64
583         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
584 #endif
585
586         set_fs(USER_DS);
587
588         /*
589          * If we exec out of a kernel thread then thread.regs will not be
590          * set.  Do it now.
591          */
592         if (!current->thread.regs) {
593                 unsigned long childregs = (unsigned long)current->thread_info +
594                                                 THREAD_SIZE;
595                 childregs -= sizeof(struct pt_regs);
596                 current->thread.regs = (struct pt_regs *)childregs;
597         }
598
599         memset(regs->gpr, 0, sizeof(regs->gpr));
600         regs->ctr = 0;
601         regs->link = 0;
602         regs->xer = 0;
603         regs->ccr = 0;
604         regs->gpr[1] = sp;
605
606 #ifdef CONFIG_PPC32
607         regs->mq = 0;
608         regs->nip = start;
609         regs->msr = MSR_USER;
610 #else
611         if (!test_thread_flag(TIF_32BIT)) {
612                 unsigned long entry, toc;
613
614                 /* start is a relocated pointer to the function descriptor for
615                  * the elf _start routine.  The first entry in the function
616                  * descriptor is the entry address of _start and the second
617                  * entry is the TOC value we need to use.
618                  */
619                 __get_user(entry, (unsigned long __user *)start);
620                 __get_user(toc, (unsigned long __user *)start+1);
621
622                 /* Check whether the e_entry function descriptor entries
623                  * need to be relocated before we can use them.
624                  */
625                 if (load_addr != 0) {
626                         entry += load_addr;
627                         toc   += load_addr;
628                 }
629                 regs->nip = entry;
630                 regs->gpr[2] = toc;
631                 regs->msr = MSR_USER64;
632         } else {
633                 regs->nip = start;
634                 regs->gpr[2] = 0;
635                 regs->msr = MSR_USER32;
636         }
637 #endif
638
639 #ifndef CONFIG_SMP
640         if (last_task_used_math == current)
641                 last_task_used_math = NULL;
642 #ifdef CONFIG_ALTIVEC
643         if (last_task_used_altivec == current)
644                 last_task_used_altivec = NULL;
645 #endif
646 #ifdef CONFIG_SPE
647         if (last_task_used_spe == current)
648                 last_task_used_spe = NULL;
649 #endif
650 #endif /* CONFIG_SMP */
651         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
652         current->thread.fpscr.val = 0;
653 #ifdef CONFIG_ALTIVEC
654         memset(current->thread.vr, 0, sizeof(current->thread.vr));
655         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
656         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
657         current->thread.vrsave = 0;
658         current->thread.used_vr = 0;
659 #endif /* CONFIG_ALTIVEC */
660 #ifdef CONFIG_SPE
661         memset(current->thread.evr, 0, sizeof(current->thread.evr));
662         current->thread.acc = 0;
663         current->thread.spefscr = 0;
664         current->thread.used_spe = 0;
665 #endif /* CONFIG_SPE */
666 }
667
668 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
669                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
670
671 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
672 {
673         struct pt_regs *regs = tsk->thread.regs;
674
675         /* This is a bit hairy.  If we are an SPE enabled  processor
676          * (have embedded fp) we store the IEEE exception enable flags in
677          * fpexc_mode.  fpexc_mode is also used for setting FP exception
678          * mode (asyn, precise, disabled) for 'Classic' FP. */
679         if (val & PR_FP_EXC_SW_ENABLE) {
680 #ifdef CONFIG_SPE
681                 tsk->thread.fpexc_mode = val &
682                         (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
683                 return 0;
684 #else
685                 return -EINVAL;
686 #endif
687         }
688
689         /* on a CONFIG_SPE this does not hurt us.  The bits that
690          * __pack_fe01 use do not overlap with bits used for
691          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
692          * on CONFIG_SPE implementations are reserved so writing to
693          * them does not change anything */
694         if (val > PR_FP_EXC_PRECISE)
695                 return -EINVAL;
696         tsk->thread.fpexc_mode = __pack_fe01(val);
697         if (regs != NULL && (regs->msr & MSR_FP) != 0)
698                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
699                         | tsk->thread.fpexc_mode;
700         return 0;
701 }
702
703 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
704 {
705         unsigned int val;
706
707         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
708 #ifdef CONFIG_SPE
709                 val = tsk->thread.fpexc_mode;
710 #else
711                 return -EINVAL;
712 #endif
713         else
714                 val = __unpack_fe01(tsk->thread.fpexc_mode);
715         return put_user(val, (unsigned int __user *) adr);
716 }
717
718 #define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
719
720 int sys_clone(unsigned long clone_flags, unsigned long usp,
721               int __user *parent_tidp, void __user *child_threadptr,
722               int __user *child_tidp, int p6,
723               struct pt_regs *regs)
724 {
725         CHECK_FULL_REGS(regs);
726         if (usp == 0)
727                 usp = regs->gpr[1];     /* stack pointer for child */
728 #ifdef CONFIG_PPC64
729         if (test_thread_flag(TIF_32BIT)) {
730                 parent_tidp = TRUNC_PTR(parent_tidp);
731                 child_tidp = TRUNC_PTR(child_tidp);
732         }
733 #endif
734         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
735 }
736
737 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
738              unsigned long p4, unsigned long p5, unsigned long p6,
739              struct pt_regs *regs)
740 {
741         CHECK_FULL_REGS(regs);
742         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
743 }
744
745 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
746               unsigned long p4, unsigned long p5, unsigned long p6,
747               struct pt_regs *regs)
748 {
749         CHECK_FULL_REGS(regs);
750         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
751                         regs, 0, NULL, NULL);
752 }
753
754 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
755                unsigned long a3, unsigned long a4, unsigned long a5,
756                struct pt_regs *regs)
757 {
758         int error;
759         char *filename;
760
761         filename = getname((char __user *) a0);
762         error = PTR_ERR(filename);
763         if (IS_ERR(filename))
764                 goto out;
765         flush_fp_to_thread(current);
766         flush_altivec_to_thread(current);
767         flush_spe_to_thread(current);
768         error = do_execve(filename, (char __user * __user *) a1,
769                           (char __user * __user *) a2, regs);
770         if (error == 0) {
771                 task_lock(current);
772                 current->ptrace &= ~PT_DTRACE;
773                 task_unlock(current);
774         }
775         putname(filename);
776 out:
777         return error;
778 }
779
780 static int validate_sp(unsigned long sp, struct task_struct *p,
781                        unsigned long nbytes)
782 {
783         unsigned long stack_page = (unsigned long)p->thread_info;
784
785         if (sp >= stack_page + sizeof(struct thread_struct)
786             && sp <= stack_page + THREAD_SIZE - nbytes)
787                 return 1;
788
789 #ifdef CONFIG_IRQSTACKS
790         stack_page = (unsigned long) hardirq_ctx[task_cpu(p)];
791         if (sp >= stack_page + sizeof(struct thread_struct)
792             && sp <= stack_page + THREAD_SIZE - nbytes)
793                 return 1;
794
795         stack_page = (unsigned long) softirq_ctx[task_cpu(p)];
796         if (sp >= stack_page + sizeof(struct thread_struct)
797             && sp <= stack_page + THREAD_SIZE - nbytes)
798                 return 1;
799 #endif
800
801         return 0;
802 }
803
804 #ifdef CONFIG_PPC64
805 #define MIN_STACK_FRAME 112     /* same as STACK_FRAME_OVERHEAD, in fact */
806 #define FRAME_LR_SAVE   2
807 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
808 #define REGS_MARKER     0x7265677368657265ul
809 #define FRAME_MARKER    12
810 #else
811 #define MIN_STACK_FRAME 16
812 #define FRAME_LR_SAVE   1
813 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
814 #define REGS_MARKER     0x72656773ul
815 #define FRAME_MARKER    2
816 #endif
817
818 unsigned long get_wchan(struct task_struct *p)
819 {
820         unsigned long ip, sp;
821         int count = 0;
822
823         if (!p || p == current || p->state == TASK_RUNNING)
824                 return 0;
825
826         sp = p->thread.ksp;
827         if (!validate_sp(sp, p, MIN_STACK_FRAME))
828                 return 0;
829
830         do {
831                 sp = *(unsigned long *)sp;
832                 if (!validate_sp(sp, p, MIN_STACK_FRAME))
833                         return 0;
834                 if (count > 0) {
835                         ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
836                         if (!in_sched_functions(ip))
837                                 return ip;
838                 }
839         } while (count++ < 16);
840         return 0;
841 }
842 EXPORT_SYMBOL(get_wchan);
843
844 static int kstack_depth_to_print = 64;
845
846 void show_stack(struct task_struct *tsk, unsigned long *stack)
847 {
848         unsigned long sp, ip, lr, newsp;
849         int count = 0;
850         int firstframe = 1;
851
852         sp = (unsigned long) stack;
853         if (tsk == NULL)
854                 tsk = current;
855         if (sp == 0) {
856                 if (tsk == current)
857                         asm("mr %0,1" : "=r" (sp));
858                 else
859                         sp = tsk->thread.ksp;
860         }
861
862         lr = 0;
863         printk("Call Trace:\n");
864         do {
865                 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
866                         return;
867
868                 stack = (unsigned long *) sp;
869                 newsp = stack[0];
870                 ip = stack[FRAME_LR_SAVE];
871                 if (!firstframe || ip != lr) {
872                         printk("["REG"] ["REG"] ", sp, ip);
873                         print_symbol("%s", ip);
874                         if (firstframe)
875                                 printk(" (unreliable)");
876                         printk("\n");
877                 }
878                 firstframe = 0;
879
880                 /*
881                  * See if this is an exception frame.
882                  * We look for the "regshere" marker in the current frame.
883                  */
884                 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
885                     && stack[FRAME_MARKER] == REGS_MARKER) {
886                         struct pt_regs *regs = (struct pt_regs *)
887                                 (sp + STACK_FRAME_OVERHEAD);
888                         printk("--- Exception: %lx", regs->trap);
889                         print_symbol(" at %s\n", regs->nip);
890                         lr = regs->link;
891                         print_symbol("    LR = %s\n", lr);
892                         firstframe = 1;
893                 }
894
895                 sp = newsp;
896         } while (count++ < kstack_depth_to_print);
897 }
898
899 void dump_stack(void)
900 {
901         show_stack(current, NULL);
902 }
903 EXPORT_SYMBOL(dump_stack);