Merge branch '85xx' of git://git.kernel.org/pub/scm/linux/kernel/git/galak/powerpc
[linux-2.6] / arch / powerpc / kernel / process.c
1 /*
2  *  Derived from "arch/i386/kernel/process.c"
3  *    Copyright (C) 1995  Linus Torvalds
4  *
5  *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
6  *  Paul Mackerras (paulus@cs.anu.edu.au)
7  *
8  *  PowerPC version
9  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
10  *
11  *  This program is free software; you can redistribute it and/or
12  *  modify it under the terms of the GNU General Public License
13  *  as published by the Free Software Foundation; either version
14  *  2 of the License, or (at your option) any later version.
15  */
16
17 #include <linux/config.h>
18 #include <linux/errno.h>
19 #include <linux/sched.h>
20 #include <linux/kernel.h>
21 #include <linux/mm.h>
22 #include <linux/smp.h>
23 #include <linux/smp_lock.h>
24 #include <linux/stddef.h>
25 #include <linux/unistd.h>
26 #include <linux/ptrace.h>
27 #include <linux/slab.h>
28 #include <linux/user.h>
29 #include <linux/elf.h>
30 #include <linux/init.h>
31 #include <linux/prctl.h>
32 #include <linux/init_task.h>
33 #include <linux/module.h>
34 #include <linux/kallsyms.h>
35 #include <linux/mqueue.h>
36 #include <linux/hardirq.h>
37 #include <linux/utsname.h>
38
39 #include <asm/pgtable.h>
40 #include <asm/uaccess.h>
41 #include <asm/system.h>
42 #include <asm/io.h>
43 #include <asm/processor.h>
44 #include <asm/mmu.h>
45 #include <asm/prom.h>
46 #include <asm/machdep.h>
47 #include <asm/time.h>
48 #include <asm/syscalls.h>
49 #ifdef CONFIG_PPC64
50 #include <asm/firmware.h>
51 #endif
52
53 extern unsigned long _get_SP(void);
54
55 #ifndef CONFIG_SMP
56 struct task_struct *last_task_used_math = NULL;
57 struct task_struct *last_task_used_altivec = NULL;
58 struct task_struct *last_task_used_spe = NULL;
59 #endif
60
61 /*
62  * Make sure the floating-point register state in the
63  * the thread_struct is up to date for task tsk.
64  */
65 void flush_fp_to_thread(struct task_struct *tsk)
66 {
67         if (tsk->thread.regs) {
68                 /*
69                  * We need to disable preemption here because if we didn't,
70                  * another process could get scheduled after the regs->msr
71                  * test but before we have finished saving the FP registers
72                  * to the thread_struct.  That process could take over the
73                  * FPU, and then when we get scheduled again we would store
74                  * bogus values for the remaining FP registers.
75                  */
76                 preempt_disable();
77                 if (tsk->thread.regs->msr & MSR_FP) {
78 #ifdef CONFIG_SMP
79                         /*
80                          * This should only ever be called for current or
81                          * for a stopped child process.  Since we save away
82                          * the FP register state on context switch on SMP,
83                          * there is something wrong if a stopped child appears
84                          * to still have its FP state in the CPU registers.
85                          */
86                         BUG_ON(tsk != current);
87 #endif
88                         giveup_fpu(current);
89                 }
90                 preempt_enable();
91         }
92 }
93
94 void enable_kernel_fp(void)
95 {
96         WARN_ON(preemptible());
97
98 #ifdef CONFIG_SMP
99         if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
100                 giveup_fpu(current);
101         else
102                 giveup_fpu(NULL);       /* just enables FP for kernel */
103 #else
104         giveup_fpu(last_task_used_math);
105 #endif /* CONFIG_SMP */
106 }
107 EXPORT_SYMBOL(enable_kernel_fp);
108
109 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
110 {
111         if (!tsk->thread.regs)
112                 return 0;
113         flush_fp_to_thread(current);
114
115         memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
116
117         return 1;
118 }
119
120 #ifdef CONFIG_ALTIVEC
121 void enable_kernel_altivec(void)
122 {
123         WARN_ON(preemptible());
124
125 #ifdef CONFIG_SMP
126         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
127                 giveup_altivec(current);
128         else
129                 giveup_altivec(NULL);   /* just enable AltiVec for kernel - force */
130 #else
131         giveup_altivec(last_task_used_altivec);
132 #endif /* CONFIG_SMP */
133 }
134 EXPORT_SYMBOL(enable_kernel_altivec);
135
136 /*
137  * Make sure the VMX/Altivec register state in the
138  * the thread_struct is up to date for task tsk.
139  */
140 void flush_altivec_to_thread(struct task_struct *tsk)
141 {
142         if (tsk->thread.regs) {
143                 preempt_disable();
144                 if (tsk->thread.regs->msr & MSR_VEC) {
145 #ifdef CONFIG_SMP
146                         BUG_ON(tsk != current);
147 #endif
148                         giveup_altivec(current);
149                 }
150                 preempt_enable();
151         }
152 }
153
154 int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
155 {
156         flush_altivec_to_thread(current);
157         memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
158         return 1;
159 }
160 #endif /* CONFIG_ALTIVEC */
161
162 #ifdef CONFIG_SPE
163
164 void enable_kernel_spe(void)
165 {
166         WARN_ON(preemptible());
167
168 #ifdef CONFIG_SMP
169         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
170                 giveup_spe(current);
171         else
172                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
173 #else
174         giveup_spe(last_task_used_spe);
175 #endif /* __SMP __ */
176 }
177 EXPORT_SYMBOL(enable_kernel_spe);
178
179 void flush_spe_to_thread(struct task_struct *tsk)
180 {
181         if (tsk->thread.regs) {
182                 preempt_disable();
183                 if (tsk->thread.regs->msr & MSR_SPE) {
184 #ifdef CONFIG_SMP
185                         BUG_ON(tsk != current);
186 #endif
187                         giveup_spe(current);
188                 }
189                 preempt_enable();
190         }
191 }
192
193 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
194 {
195         flush_spe_to_thread(current);
196         /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
197         memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
198         return 1;
199 }
200 #endif /* CONFIG_SPE */
201
202 #ifndef CONFIG_SMP
203 /*
204  * If we are doing lazy switching of CPU state (FP, altivec or SPE),
205  * and the current task has some state, discard it.
206  */
207 void discard_lazy_cpu_state(void)
208 {
209         preempt_disable();
210         if (last_task_used_math == current)
211                 last_task_used_math = NULL;
212 #ifdef CONFIG_ALTIVEC
213         if (last_task_used_altivec == current)
214                 last_task_used_altivec = NULL;
215 #endif /* CONFIG_ALTIVEC */
216 #ifdef CONFIG_SPE
217         if (last_task_used_spe == current)
218                 last_task_used_spe = NULL;
219 #endif
220         preempt_enable();
221 }
222 #endif /* CONFIG_SMP */
223
224 #ifdef CONFIG_PPC_MERGE         /* XXX for now */
225 int set_dabr(unsigned long dabr)
226 {
227         if (ppc_md.set_dabr)
228                 return ppc_md.set_dabr(dabr);
229
230         mtspr(SPRN_DABR, dabr);
231         return 0;
232 }
233 #endif
234
235 #ifdef CONFIG_PPC64
236 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
237 static DEFINE_PER_CPU(unsigned long, current_dabr);
238 #endif
239
240 struct task_struct *__switch_to(struct task_struct *prev,
241         struct task_struct *new)
242 {
243         struct thread_struct *new_thread, *old_thread;
244         unsigned long flags;
245         struct task_struct *last;
246
247 #ifdef CONFIG_SMP
248         /* avoid complexity of lazy save/restore of fpu
249          * by just saving it every time we switch out if
250          * this task used the fpu during the last quantum.
251          *
252          * If it tries to use the fpu again, it'll trap and
253          * reload its fp regs.  So we don't have to do a restore
254          * every switch, just a save.
255          *  -- Cort
256          */
257         if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
258                 giveup_fpu(prev);
259 #ifdef CONFIG_ALTIVEC
260         /*
261          * If the previous thread used altivec in the last quantum
262          * (thus changing altivec regs) then save them.
263          * We used to check the VRSAVE register but not all apps
264          * set it, so we don't rely on it now (and in fact we need
265          * to save & restore VSCR even if VRSAVE == 0).  -- paulus
266          *
267          * On SMP we always save/restore altivec regs just to avoid the
268          * complexity of changing processors.
269          *  -- Cort
270          */
271         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
272                 giveup_altivec(prev);
273 #endif /* CONFIG_ALTIVEC */
274 #ifdef CONFIG_SPE
275         /*
276          * If the previous thread used spe in the last quantum
277          * (thus changing spe regs) then save them.
278          *
279          * On SMP we always save/restore spe regs just to avoid the
280          * complexity of changing processors.
281          */
282         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
283                 giveup_spe(prev);
284 #endif /* CONFIG_SPE */
285
286 #else  /* CONFIG_SMP */
287 #ifdef CONFIG_ALTIVEC
288         /* Avoid the trap.  On smp this this never happens since
289          * we don't set last_task_used_altivec -- Cort
290          */
291         if (new->thread.regs && last_task_used_altivec == new)
292                 new->thread.regs->msr |= MSR_VEC;
293 #endif /* CONFIG_ALTIVEC */
294 #ifdef CONFIG_SPE
295         /* Avoid the trap.  On smp this this never happens since
296          * we don't set last_task_used_spe
297          */
298         if (new->thread.regs && last_task_used_spe == new)
299                 new->thread.regs->msr |= MSR_SPE;
300 #endif /* CONFIG_SPE */
301
302 #endif /* CONFIG_SMP */
303
304 #ifdef CONFIG_PPC64     /* for now */
305         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
306                 set_dabr(new->thread.dabr);
307                 __get_cpu_var(current_dabr) = new->thread.dabr;
308         }
309
310         flush_tlb_pending();
311 #endif
312
313         new_thread = &new->thread;
314         old_thread = &current->thread;
315
316 #ifdef CONFIG_PPC64
317         /*
318          * Collect processor utilization data per process
319          */
320         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
321                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
322                 long unsigned start_tb, current_tb;
323                 start_tb = old_thread->start_tb;
324                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
325                 old_thread->accum_tb += (current_tb - start_tb);
326                 new_thread->start_tb = current_tb;
327         }
328 #endif
329
330         local_irq_save(flags);
331
332         account_system_vtime(current);
333         account_process_vtime(current);
334         calculate_steal_time();
335
336         last = _switch(old_thread, new_thread);
337
338         local_irq_restore(flags);
339
340         return last;
341 }
342
343 static int instructions_to_print = 16;
344
345 #ifdef CONFIG_PPC64
346 #define BAD_PC(pc)      ((REGION_ID(pc) != KERNEL_REGION_ID) && \
347                          (REGION_ID(pc) != VMALLOC_REGION_ID))
348 #else
349 #define BAD_PC(pc)      ((pc) < KERNELBASE)
350 #endif
351
352 static void show_instructions(struct pt_regs *regs)
353 {
354         int i;
355         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
356                         sizeof(int));
357
358         printk("Instruction dump:");
359
360         for (i = 0; i < instructions_to_print; i++) {
361                 int instr;
362
363                 if (!(i % 8))
364                         printk("\n");
365
366                 /* We use __get_user here *only* to avoid an OOPS on a
367                  * bad address because the pc *should* only be a
368                  * kernel address.
369                  */
370                 if (BAD_PC(pc) || __get_user(instr, (unsigned int __user *)pc)) {
371                         printk("XXXXXXXX ");
372                 } else {
373                         if (regs->nip == pc)
374                                 printk("<%08x> ", instr);
375                         else
376                                 printk("%08x ", instr);
377                 }
378
379                 pc += sizeof(int);
380         }
381
382         printk("\n");
383 }
384
385 static struct regbit {
386         unsigned long bit;
387         const char *name;
388 } msr_bits[] = {
389         {MSR_EE,        "EE"},
390         {MSR_PR,        "PR"},
391         {MSR_FP,        "FP"},
392         {MSR_ME,        "ME"},
393         {MSR_IR,        "IR"},
394         {MSR_DR,        "DR"},
395         {0,             NULL}
396 };
397
398 static void printbits(unsigned long val, struct regbit *bits)
399 {
400         const char *sep = "";
401
402         printk("<");
403         for (; bits->bit; ++bits)
404                 if (val & bits->bit) {
405                         printk("%s%s", sep, bits->name);
406                         sep = ",";
407                 }
408         printk(">");
409 }
410
411 #ifdef CONFIG_PPC64
412 #define REG             "%016lX"
413 #define REGS_PER_LINE   4
414 #define LAST_VOLATILE   13
415 #else
416 #define REG             "%08lX"
417 #define REGS_PER_LINE   8
418 #define LAST_VOLATILE   12
419 #endif
420
421 void show_regs(struct pt_regs * regs)
422 {
423         int i, trap;
424
425         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
426                regs->nip, regs->link, regs->ctr);
427         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
428                regs, regs->trap, print_tainted(), system_utsname.release);
429         printk("MSR: "REG" ", regs->msr);
430         printbits(regs->msr, msr_bits);
431         printk("  CR: %08lX  XER: %08lX\n", regs->ccr, regs->xer);
432         trap = TRAP(regs);
433         if (trap == 0x300 || trap == 0x600)
434                 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
435         printk("TASK = %p[%d] '%s' THREAD: %p",
436                current, current->pid, current->comm, task_thread_info(current));
437
438 #ifdef CONFIG_SMP
439         printk(" CPU: %d", smp_processor_id());
440 #endif /* CONFIG_SMP */
441
442         for (i = 0;  i < 32;  i++) {
443                 if ((i % REGS_PER_LINE) == 0)
444                         printk("\n" KERN_INFO "GPR%02d: ", i);
445                 printk(REG " ", regs->gpr[i]);
446                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
447                         break;
448         }
449         printk("\n");
450 #ifdef CONFIG_KALLSYMS
451         /*
452          * Lookup NIP late so we have the best change of getting the
453          * above info out without failing
454          */
455         printk("NIP ["REG"] ", regs->nip);
456         print_symbol("%s\n", regs->nip);
457         printk("LR ["REG"] ", regs->link);
458         print_symbol("%s\n", regs->link);
459 #endif
460         show_stack(current, (unsigned long *) regs->gpr[1]);
461         if (!user_mode(regs))
462                 show_instructions(regs);
463 }
464
465 void exit_thread(void)
466 {
467         discard_lazy_cpu_state();
468 }
469
470 void flush_thread(void)
471 {
472 #ifdef CONFIG_PPC64
473         struct thread_info *t = current_thread_info();
474
475         if (t->flags & _TIF_ABI_PENDING)
476                 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
477 #endif
478
479         discard_lazy_cpu_state();
480
481 #ifdef CONFIG_PPC64     /* for now */
482         if (current->thread.dabr) {
483                 current->thread.dabr = 0;
484                 set_dabr(0);
485         }
486 #endif
487 }
488
489 void
490 release_thread(struct task_struct *t)
491 {
492 }
493
494 /*
495  * This gets called before we allocate a new thread and copy
496  * the current task into it.
497  */
498 void prepare_to_copy(struct task_struct *tsk)
499 {
500         flush_fp_to_thread(current);
501         flush_altivec_to_thread(current);
502         flush_spe_to_thread(current);
503 }
504
505 /*
506  * Copy a thread..
507  */
508 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
509                 unsigned long unused, struct task_struct *p,
510                 struct pt_regs *regs)
511 {
512         struct pt_regs *childregs, *kregs;
513         extern void ret_from_fork(void);
514         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
515
516         CHECK_FULL_REGS(regs);
517         /* Copy registers */
518         sp -= sizeof(struct pt_regs);
519         childregs = (struct pt_regs *) sp;
520         *childregs = *regs;
521         if ((childregs->msr & MSR_PR) == 0) {
522                 /* for kernel thread, set `current' and stackptr in new task */
523                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
524 #ifdef CONFIG_PPC32
525                 childregs->gpr[2] = (unsigned long) p;
526 #else
527                 clear_tsk_thread_flag(p, TIF_32BIT);
528 #endif
529                 p->thread.regs = NULL;  /* no user register state */
530         } else {
531                 childregs->gpr[1] = usp;
532                 p->thread.regs = childregs;
533                 if (clone_flags & CLONE_SETTLS) {
534 #ifdef CONFIG_PPC64
535                         if (!test_thread_flag(TIF_32BIT))
536                                 childregs->gpr[13] = childregs->gpr[6];
537                         else
538 #endif
539                                 childregs->gpr[2] = childregs->gpr[6];
540                 }
541         }
542         childregs->gpr[3] = 0;  /* Result from fork() */
543         sp -= STACK_FRAME_OVERHEAD;
544
545         /*
546          * The way this works is that at some point in the future
547          * some task will call _switch to switch to the new task.
548          * That will pop off the stack frame created below and start
549          * the new task running at ret_from_fork.  The new task will
550          * do some house keeping and then return from the fork or clone
551          * system call, using the stack frame created above.
552          */
553         sp -= sizeof(struct pt_regs);
554         kregs = (struct pt_regs *) sp;
555         sp -= STACK_FRAME_OVERHEAD;
556         p->thread.ksp = sp;
557
558 #ifdef CONFIG_PPC64
559         if (cpu_has_feature(CPU_FTR_SLB)) {
560                 unsigned long sp_vsid = get_kernel_vsid(sp);
561                 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
562
563                 sp_vsid <<= SLB_VSID_SHIFT;
564                 sp_vsid |= SLB_VSID_KERNEL | llp;
565                 p->thread.ksp_vsid = sp_vsid;
566         }
567
568         /*
569          * The PPC64 ABI makes use of a TOC to contain function 
570          * pointers.  The function (ret_from_except) is actually a pointer
571          * to the TOC entry.  The first entry is a pointer to the actual
572          * function.
573          */
574         kregs->nip = *((unsigned long *)ret_from_fork);
575 #else
576         kregs->nip = (unsigned long)ret_from_fork;
577         p->thread.last_syscall = -1;
578 #endif
579
580         return 0;
581 }
582
583 /*
584  * Set up a thread for executing a new program
585  */
586 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
587 {
588 #ifdef CONFIG_PPC64
589         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
590 #endif
591
592         set_fs(USER_DS);
593
594         /*
595          * If we exec out of a kernel thread then thread.regs will not be
596          * set.  Do it now.
597          */
598         if (!current->thread.regs) {
599                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
600                 current->thread.regs = regs - 1;
601         }
602
603         memset(regs->gpr, 0, sizeof(regs->gpr));
604         regs->ctr = 0;
605         regs->link = 0;
606         regs->xer = 0;
607         regs->ccr = 0;
608         regs->gpr[1] = sp;
609
610 #ifdef CONFIG_PPC32
611         regs->mq = 0;
612         regs->nip = start;
613         regs->msr = MSR_USER;
614 #else
615         if (!test_thread_flag(TIF_32BIT)) {
616                 unsigned long entry, toc;
617
618                 /* start is a relocated pointer to the function descriptor for
619                  * the elf _start routine.  The first entry in the function
620                  * descriptor is the entry address of _start and the second
621                  * entry is the TOC value we need to use.
622                  */
623                 __get_user(entry, (unsigned long __user *)start);
624                 __get_user(toc, (unsigned long __user *)start+1);
625
626                 /* Check whether the e_entry function descriptor entries
627                  * need to be relocated before we can use them.
628                  */
629                 if (load_addr != 0) {
630                         entry += load_addr;
631                         toc   += load_addr;
632                 }
633                 regs->nip = entry;
634                 regs->gpr[2] = toc;
635                 regs->msr = MSR_USER64;
636         } else {
637                 regs->nip = start;
638                 regs->gpr[2] = 0;
639                 regs->msr = MSR_USER32;
640         }
641 #endif
642
643         discard_lazy_cpu_state();
644         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
645         current->thread.fpscr.val = 0;
646 #ifdef CONFIG_ALTIVEC
647         memset(current->thread.vr, 0, sizeof(current->thread.vr));
648         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
649         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
650         current->thread.vrsave = 0;
651         current->thread.used_vr = 0;
652 #endif /* CONFIG_ALTIVEC */
653 #ifdef CONFIG_SPE
654         memset(current->thread.evr, 0, sizeof(current->thread.evr));
655         current->thread.acc = 0;
656         current->thread.spefscr = 0;
657         current->thread.used_spe = 0;
658 #endif /* CONFIG_SPE */
659 }
660
661 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
662                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
663
664 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
665 {
666         struct pt_regs *regs = tsk->thread.regs;
667
668         /* This is a bit hairy.  If we are an SPE enabled  processor
669          * (have embedded fp) we store the IEEE exception enable flags in
670          * fpexc_mode.  fpexc_mode is also used for setting FP exception
671          * mode (asyn, precise, disabled) for 'Classic' FP. */
672         if (val & PR_FP_EXC_SW_ENABLE) {
673 #ifdef CONFIG_SPE
674                 tsk->thread.fpexc_mode = val &
675                         (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
676                 return 0;
677 #else
678                 return -EINVAL;
679 #endif
680         }
681
682         /* on a CONFIG_SPE this does not hurt us.  The bits that
683          * __pack_fe01 use do not overlap with bits used for
684          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
685          * on CONFIG_SPE implementations are reserved so writing to
686          * them does not change anything */
687         if (val > PR_FP_EXC_PRECISE)
688                 return -EINVAL;
689         tsk->thread.fpexc_mode = __pack_fe01(val);
690         if (regs != NULL && (regs->msr & MSR_FP) != 0)
691                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
692                         | tsk->thread.fpexc_mode;
693         return 0;
694 }
695
696 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
697 {
698         unsigned int val;
699
700         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
701 #ifdef CONFIG_SPE
702                 val = tsk->thread.fpexc_mode;
703 #else
704                 return -EINVAL;
705 #endif
706         else
707                 val = __unpack_fe01(tsk->thread.fpexc_mode);
708         return put_user(val, (unsigned int __user *) adr);
709 }
710
711 #define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
712
713 int sys_clone(unsigned long clone_flags, unsigned long usp,
714               int __user *parent_tidp, void __user *child_threadptr,
715               int __user *child_tidp, int p6,
716               struct pt_regs *regs)
717 {
718         CHECK_FULL_REGS(regs);
719         if (usp == 0)
720                 usp = regs->gpr[1];     /* stack pointer for child */
721 #ifdef CONFIG_PPC64
722         if (test_thread_flag(TIF_32BIT)) {
723                 parent_tidp = TRUNC_PTR(parent_tidp);
724                 child_tidp = TRUNC_PTR(child_tidp);
725         }
726 #endif
727         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
728 }
729
730 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
731              unsigned long p4, unsigned long p5, unsigned long p6,
732              struct pt_regs *regs)
733 {
734         CHECK_FULL_REGS(regs);
735         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
736 }
737
738 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
739               unsigned long p4, unsigned long p5, unsigned long p6,
740               struct pt_regs *regs)
741 {
742         CHECK_FULL_REGS(regs);
743         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
744                         regs, 0, NULL, NULL);
745 }
746
747 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
748                unsigned long a3, unsigned long a4, unsigned long a5,
749                struct pt_regs *regs)
750 {
751         int error;
752         char *filename;
753
754         filename = getname((char __user *) a0);
755         error = PTR_ERR(filename);
756         if (IS_ERR(filename))
757                 goto out;
758         flush_fp_to_thread(current);
759         flush_altivec_to_thread(current);
760         flush_spe_to_thread(current);
761         error = do_execve(filename, (char __user * __user *) a1,
762                           (char __user * __user *) a2, regs);
763         if (error == 0) {
764                 task_lock(current);
765                 current->ptrace &= ~PT_DTRACE;
766                 task_unlock(current);
767         }
768         putname(filename);
769 out:
770         return error;
771 }
772
773 int validate_sp(unsigned long sp, struct task_struct *p,
774                        unsigned long nbytes)
775 {
776         unsigned long stack_page = (unsigned long)task_stack_page(p);
777
778         if (sp >= stack_page + sizeof(struct thread_struct)
779             && sp <= stack_page + THREAD_SIZE - nbytes)
780                 return 1;
781
782 #ifdef CONFIG_IRQSTACKS
783         stack_page = (unsigned long) hardirq_ctx[task_cpu(p)];
784         if (sp >= stack_page + sizeof(struct thread_struct)
785             && sp <= stack_page + THREAD_SIZE - nbytes)
786                 return 1;
787
788         stack_page = (unsigned long) softirq_ctx[task_cpu(p)];
789         if (sp >= stack_page + sizeof(struct thread_struct)
790             && sp <= stack_page + THREAD_SIZE - nbytes)
791                 return 1;
792 #endif
793
794         return 0;
795 }
796
797 #ifdef CONFIG_PPC64
798 #define MIN_STACK_FRAME 112     /* same as STACK_FRAME_OVERHEAD, in fact */
799 #define FRAME_LR_SAVE   2
800 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
801 #define REGS_MARKER     0x7265677368657265ul
802 #define FRAME_MARKER    12
803 #else
804 #define MIN_STACK_FRAME 16
805 #define FRAME_LR_SAVE   1
806 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
807 #define REGS_MARKER     0x72656773ul
808 #define FRAME_MARKER    2
809 #endif
810
811 EXPORT_SYMBOL(validate_sp);
812
813 unsigned long get_wchan(struct task_struct *p)
814 {
815         unsigned long ip, sp;
816         int count = 0;
817
818         if (!p || p == current || p->state == TASK_RUNNING)
819                 return 0;
820
821         sp = p->thread.ksp;
822         if (!validate_sp(sp, p, MIN_STACK_FRAME))
823                 return 0;
824
825         do {
826                 sp = *(unsigned long *)sp;
827                 if (!validate_sp(sp, p, MIN_STACK_FRAME))
828                         return 0;
829                 if (count > 0) {
830                         ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
831                         if (!in_sched_functions(ip))
832                                 return ip;
833                 }
834         } while (count++ < 16);
835         return 0;
836 }
837 EXPORT_SYMBOL(get_wchan);
838
839 static int kstack_depth_to_print = 64;
840
841 void show_stack(struct task_struct *tsk, unsigned long *stack)
842 {
843         unsigned long sp, ip, lr, newsp;
844         int count = 0;
845         int firstframe = 1;
846
847         sp = (unsigned long) stack;
848         if (tsk == NULL)
849                 tsk = current;
850         if (sp == 0) {
851                 if (tsk == current)
852                         asm("mr %0,1" : "=r" (sp));
853                 else
854                         sp = tsk->thread.ksp;
855         }
856
857         lr = 0;
858         printk("Call Trace:\n");
859         do {
860                 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
861                         return;
862
863                 stack = (unsigned long *) sp;
864                 newsp = stack[0];
865                 ip = stack[FRAME_LR_SAVE];
866                 if (!firstframe || ip != lr) {
867                         printk("["REG"] ["REG"] ", sp, ip);
868                         print_symbol("%s", ip);
869                         if (firstframe)
870                                 printk(" (unreliable)");
871                         printk("\n");
872                 }
873                 firstframe = 0;
874
875                 /*
876                  * See if this is an exception frame.
877                  * We look for the "regshere" marker in the current frame.
878                  */
879                 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
880                     && stack[FRAME_MARKER] == REGS_MARKER) {
881                         struct pt_regs *regs = (struct pt_regs *)
882                                 (sp + STACK_FRAME_OVERHEAD);
883                         printk("--- Exception: %lx", regs->trap);
884                         print_symbol(" at %s\n", regs->nip);
885                         lr = regs->link;
886                         print_symbol("    LR = %s\n", lr);
887                         firstframe = 1;
888                 }
889
890                 sp = newsp;
891         } while (count++ < kstack_depth_to_print);
892 }
893
894 void dump_stack(void)
895 {
896         show_stack(current, NULL);
897 }
898 EXPORT_SYMBOL(dump_stack);
899
900 #ifdef CONFIG_PPC64
901 void ppc64_runlatch_on(void)
902 {
903         unsigned long ctrl;
904
905         if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) {
906                 HMT_medium();
907
908                 ctrl = mfspr(SPRN_CTRLF);
909                 ctrl |= CTRL_RUNLATCH;
910                 mtspr(SPRN_CTRLT, ctrl);
911
912                 set_thread_flag(TIF_RUNLATCH);
913         }
914 }
915
916 void ppc64_runlatch_off(void)
917 {
918         unsigned long ctrl;
919
920         if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) {
921                 HMT_medium();
922
923                 clear_thread_flag(TIF_RUNLATCH);
924
925                 ctrl = mfspr(SPRN_CTRLF);
926                 ctrl &= ~CTRL_RUNLATCH;
927                 mtspr(SPRN_CTRLT, ctrl);
928         }
929 }
930 #endif