Merge commit '85082fd7cbe3173198aac0eb5e85ab1edcc6352c' into test-build
[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/errno.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.h>
21 #include <linux/smp.h>
22 #include <linux/stddef.h>
23 #include <linux/unistd.h>
24 #include <linux/ptrace.h>
25 #include <linux/slab.h>
26 #include <linux/user.h>
27 #include <linux/elf.h>
28 #include <linux/init.h>
29 #include <linux/prctl.h>
30 #include <linux/init_task.h>
31 #include <linux/module.h>
32 #include <linux/kallsyms.h>
33 #include <linux/mqueue.h>
34 #include <linux/hardirq.h>
35 #include <linux/utsname.h>
36
37 #include <asm/pgtable.h>
38 #include <asm/uaccess.h>
39 #include <asm/system.h>
40 #include <asm/io.h>
41 #include <asm/processor.h>
42 #include <asm/mmu.h>
43 #include <asm/prom.h>
44 #include <asm/machdep.h>
45 #include <asm/time.h>
46 #include <asm/syscalls.h>
47 #ifdef CONFIG_PPC64
48 #include <asm/firmware.h>
49 #endif
50
51 extern unsigned long _get_SP(void);
52
53 #ifndef CONFIG_SMP
54 struct task_struct *last_task_used_math = NULL;
55 struct task_struct *last_task_used_altivec = NULL;
56 struct task_struct *last_task_used_vsx = NULL;
57 struct task_struct *last_task_used_spe = NULL;
58 #endif
59
60 /*
61  * Make sure the floating-point register state in the
62  * the thread_struct is up to date for task tsk.
63  */
64 void flush_fp_to_thread(struct task_struct *tsk)
65 {
66         if (tsk->thread.regs) {
67                 /*
68                  * We need to disable preemption here because if we didn't,
69                  * another process could get scheduled after the regs->msr
70                  * test but before we have finished saving the FP registers
71                  * to the thread_struct.  That process could take over the
72                  * FPU, and then when we get scheduled again we would store
73                  * bogus values for the remaining FP registers.
74                  */
75                 preempt_disable();
76                 if (tsk->thread.regs->msr & MSR_FP) {
77 #ifdef CONFIG_SMP
78                         /*
79                          * This should only ever be called for current or
80                          * for a stopped child process.  Since we save away
81                          * the FP register state on context switch on SMP,
82                          * there is something wrong if a stopped child appears
83                          * to still have its FP state in the CPU registers.
84                          */
85                         BUG_ON(tsk != current);
86 #endif
87                         giveup_fpu(tsk);
88                 }
89                 preempt_enable();
90         }
91 }
92
93 void enable_kernel_fp(void)
94 {
95         WARN_ON(preemptible());
96
97 #ifdef CONFIG_SMP
98         if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
99                 giveup_fpu(current);
100         else
101                 giveup_fpu(NULL);       /* just enables FP for kernel */
102 #else
103         giveup_fpu(last_task_used_math);
104 #endif /* CONFIG_SMP */
105 }
106 EXPORT_SYMBOL(enable_kernel_fp);
107
108 #ifdef CONFIG_ALTIVEC
109 void enable_kernel_altivec(void)
110 {
111         WARN_ON(preemptible());
112
113 #ifdef CONFIG_SMP
114         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
115                 giveup_altivec(current);
116         else
117                 giveup_altivec(NULL);   /* just enable AltiVec for kernel - force */
118 #else
119         giveup_altivec(last_task_used_altivec);
120 #endif /* CONFIG_SMP */
121 }
122 EXPORT_SYMBOL(enable_kernel_altivec);
123
124 /*
125  * Make sure the VMX/Altivec register state in the
126  * the thread_struct is up to date for task tsk.
127  */
128 void flush_altivec_to_thread(struct task_struct *tsk)
129 {
130         if (tsk->thread.regs) {
131                 preempt_disable();
132                 if (tsk->thread.regs->msr & MSR_VEC) {
133 #ifdef CONFIG_SMP
134                         BUG_ON(tsk != current);
135 #endif
136                         giveup_altivec(tsk);
137                 }
138                 preempt_enable();
139         }
140 }
141 #endif /* CONFIG_ALTIVEC */
142
143 #ifdef CONFIG_VSX
144 #if 0
145 /* not currently used, but some crazy RAID module might want to later */
146 void enable_kernel_vsx(void)
147 {
148         WARN_ON(preemptible());
149
150 #ifdef CONFIG_SMP
151         if (current->thread.regs && (current->thread.regs->msr & MSR_VSX))
152                 giveup_vsx(current);
153         else
154                 giveup_vsx(NULL);       /* just enable vsx for kernel - force */
155 #else
156         giveup_vsx(last_task_used_vsx);
157 #endif /* CONFIG_SMP */
158 }
159 EXPORT_SYMBOL(enable_kernel_vsx);
160 #endif
161
162 void giveup_vsx(struct task_struct *tsk)
163 {
164         giveup_fpu(tsk);
165         giveup_altivec(tsk);
166         __giveup_vsx(tsk);
167 }
168
169 void flush_vsx_to_thread(struct task_struct *tsk)
170 {
171         if (tsk->thread.regs) {
172                 preempt_disable();
173                 if (tsk->thread.regs->msr & MSR_VSX) {
174 #ifdef CONFIG_SMP
175                         BUG_ON(tsk != current);
176 #endif
177                         giveup_vsx(tsk);
178                 }
179                 preempt_enable();
180         }
181 }
182 #endif /* CONFIG_VSX */
183
184 #ifdef CONFIG_SPE
185
186 void enable_kernel_spe(void)
187 {
188         WARN_ON(preemptible());
189
190 #ifdef CONFIG_SMP
191         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
192                 giveup_spe(current);
193         else
194                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
195 #else
196         giveup_spe(last_task_used_spe);
197 #endif /* __SMP __ */
198 }
199 EXPORT_SYMBOL(enable_kernel_spe);
200
201 void flush_spe_to_thread(struct task_struct *tsk)
202 {
203         if (tsk->thread.regs) {
204                 preempt_disable();
205                 if (tsk->thread.regs->msr & MSR_SPE) {
206 #ifdef CONFIG_SMP
207                         BUG_ON(tsk != current);
208 #endif
209                         giveup_spe(tsk);
210                 }
211                 preempt_enable();
212         }
213 }
214 #endif /* CONFIG_SPE */
215
216 #ifndef CONFIG_SMP
217 /*
218  * If we are doing lazy switching of CPU state (FP, altivec or SPE),
219  * and the current task has some state, discard it.
220  */
221 void discard_lazy_cpu_state(void)
222 {
223         preempt_disable();
224         if (last_task_used_math == current)
225                 last_task_used_math = NULL;
226 #ifdef CONFIG_ALTIVEC
227         if (last_task_used_altivec == current)
228                 last_task_used_altivec = NULL;
229 #endif /* CONFIG_ALTIVEC */
230 #ifdef CONFIG_VSX
231         if (last_task_used_vsx == current)
232                 last_task_used_vsx = NULL;
233 #endif /* CONFIG_VSX */
234 #ifdef CONFIG_SPE
235         if (last_task_used_spe == current)
236                 last_task_used_spe = NULL;
237 #endif
238         preempt_enable();
239 }
240 #endif /* CONFIG_SMP */
241
242 static DEFINE_PER_CPU(unsigned long, current_dabr);
243
244 int set_dabr(unsigned long dabr)
245 {
246         __get_cpu_var(current_dabr) = dabr;
247
248 #ifdef CONFIG_PPC_MERGE         /* XXX for now */
249         if (ppc_md.set_dabr)
250                 return ppc_md.set_dabr(dabr);
251 #endif
252
253         /* XXX should we have a CPU_FTR_HAS_DABR ? */
254 #if defined(CONFIG_PPC64) || defined(CONFIG_6xx)
255         mtspr(SPRN_DABR, dabr);
256 #endif
257         return 0;
258 }
259
260 #ifdef CONFIG_PPC64
261 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
262 #endif
263
264 struct task_struct *__switch_to(struct task_struct *prev,
265         struct task_struct *new)
266 {
267         struct thread_struct *new_thread, *old_thread;
268         unsigned long flags;
269         struct task_struct *last;
270
271 #ifdef CONFIG_SMP
272         /* avoid complexity of lazy save/restore of fpu
273          * by just saving it every time we switch out if
274          * this task used the fpu during the last quantum.
275          *
276          * If it tries to use the fpu again, it'll trap and
277          * reload its fp regs.  So we don't have to do a restore
278          * every switch, just a save.
279          *  -- Cort
280          */
281         if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
282                 giveup_fpu(prev);
283 #ifdef CONFIG_ALTIVEC
284         /*
285          * If the previous thread used altivec in the last quantum
286          * (thus changing altivec regs) then save them.
287          * We used to check the VRSAVE register but not all apps
288          * set it, so we don't rely on it now (and in fact we need
289          * to save & restore VSCR even if VRSAVE == 0).  -- paulus
290          *
291          * On SMP we always save/restore altivec regs just to avoid the
292          * complexity of changing processors.
293          *  -- Cort
294          */
295         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
296                 giveup_altivec(prev);
297 #endif /* CONFIG_ALTIVEC */
298 #ifdef CONFIG_VSX
299         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX))
300                 /* VMX and FPU registers are already save here */
301                 __giveup_vsx(prev);
302 #endif /* CONFIG_VSX */
303 #ifdef CONFIG_SPE
304         /*
305          * If the previous thread used spe in the last quantum
306          * (thus changing spe regs) then save them.
307          *
308          * On SMP we always save/restore spe regs just to avoid the
309          * complexity of changing processors.
310          */
311         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
312                 giveup_spe(prev);
313 #endif /* CONFIG_SPE */
314
315 #else  /* CONFIG_SMP */
316 #ifdef CONFIG_ALTIVEC
317         /* Avoid the trap.  On smp this this never happens since
318          * we don't set last_task_used_altivec -- Cort
319          */
320         if (new->thread.regs && last_task_used_altivec == new)
321                 new->thread.regs->msr |= MSR_VEC;
322 #endif /* CONFIG_ALTIVEC */
323 #ifdef CONFIG_VSX
324         if (new->thread.regs && last_task_used_vsx == new)
325                 new->thread.regs->msr |= MSR_VSX;
326 #endif /* CONFIG_VSX */
327 #ifdef CONFIG_SPE
328         /* Avoid the trap.  On smp this this never happens since
329          * we don't set last_task_used_spe
330          */
331         if (new->thread.regs && last_task_used_spe == new)
332                 new->thread.regs->msr |= MSR_SPE;
333 #endif /* CONFIG_SPE */
334
335 #endif /* CONFIG_SMP */
336
337         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
338                 set_dabr(new->thread.dabr);
339
340         new_thread = &new->thread;
341         old_thread = &current->thread;
342
343 #ifdef CONFIG_PPC64
344         /*
345          * Collect processor utilization data per process
346          */
347         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
348                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
349                 long unsigned start_tb, current_tb;
350                 start_tb = old_thread->start_tb;
351                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
352                 old_thread->accum_tb += (current_tb - start_tb);
353                 new_thread->start_tb = current_tb;
354         }
355 #endif
356
357         local_irq_save(flags);
358
359         account_system_vtime(current);
360         account_process_vtime(current);
361         calculate_steal_time();
362
363         /*
364          * We can't take a PMU exception inside _switch() since there is a
365          * window where the kernel stack SLB and the kernel stack are out
366          * of sync. Hard disable here.
367          */
368         hard_irq_disable();
369         last = _switch(old_thread, new_thread);
370
371         local_irq_restore(flags);
372
373         return last;
374 }
375
376 static int instructions_to_print = 16;
377
378 static void show_instructions(struct pt_regs *regs)
379 {
380         int i;
381         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
382                         sizeof(int));
383
384         printk("Instruction dump:");
385
386         for (i = 0; i < instructions_to_print; i++) {
387                 int instr;
388
389                 if (!(i % 8))
390                         printk("\n");
391
392 #if !defined(CONFIG_BOOKE)
393                 /* If executing with the IMMU off, adjust pc rather
394                  * than print XXXXXXXX.
395                  */
396                 if (!(regs->msr & MSR_IR))
397                         pc = (unsigned long)phys_to_virt(pc);
398 #endif
399
400                 /* We use __get_user here *only* to avoid an OOPS on a
401                  * bad address because the pc *should* only be a
402                  * kernel address.
403                  */
404                 if (!__kernel_text_address(pc) ||
405                      __get_user(instr, (unsigned int __user *)pc)) {
406                         printk("XXXXXXXX ");
407                 } else {
408                         if (regs->nip == pc)
409                                 printk("<%08x> ", instr);
410                         else
411                                 printk("%08x ", instr);
412                 }
413
414                 pc += sizeof(int);
415         }
416
417         printk("\n");
418 }
419
420 static struct regbit {
421         unsigned long bit;
422         const char *name;
423 } msr_bits[] = {
424         {MSR_EE,        "EE"},
425         {MSR_PR,        "PR"},
426         {MSR_FP,        "FP"},
427         {MSR_VEC,       "VEC"},
428         {MSR_VSX,       "VSX"},
429         {MSR_ME,        "ME"},
430         {MSR_IR,        "IR"},
431         {MSR_DR,        "DR"},
432         {0,             NULL}
433 };
434
435 static void printbits(unsigned long val, struct regbit *bits)
436 {
437         const char *sep = "";
438
439         printk("<");
440         for (; bits->bit; ++bits)
441                 if (val & bits->bit) {
442                         printk("%s%s", sep, bits->name);
443                         sep = ",";
444                 }
445         printk(">");
446 }
447
448 #ifdef CONFIG_PPC64
449 #define REG             "%016lx"
450 #define REGS_PER_LINE   4
451 #define LAST_VOLATILE   13
452 #else
453 #define REG             "%08lx"
454 #define REGS_PER_LINE   8
455 #define LAST_VOLATILE   12
456 #endif
457
458 void show_regs(struct pt_regs * regs)
459 {
460         int i, trap;
461
462         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
463                regs->nip, regs->link, regs->ctr);
464         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
465                regs, regs->trap, print_tainted(), init_utsname()->release);
466         printk("MSR: "REG" ", regs->msr);
467         printbits(regs->msr, msr_bits);
468         printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
469         trap = TRAP(regs);
470         if (trap == 0x300 || trap == 0x600)
471 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
472                 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr);
473 #else
474                 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
475 #endif
476         printk("TASK = %p[%d] '%s' THREAD: %p",
477                current, task_pid_nr(current), current->comm, task_thread_info(current));
478
479 #ifdef CONFIG_SMP
480         printk(" CPU: %d", raw_smp_processor_id());
481 #endif /* CONFIG_SMP */
482
483         for (i = 0;  i < 32;  i++) {
484                 if ((i % REGS_PER_LINE) == 0)
485                         printk("\n" KERN_INFO "GPR%02d: ", i);
486                 printk(REG " ", regs->gpr[i]);
487                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
488                         break;
489         }
490         printk("\n");
491 #ifdef CONFIG_KALLSYMS
492         /*
493          * Lookup NIP late so we have the best change of getting the
494          * above info out without failing
495          */
496         printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
497         printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
498 #endif
499         show_stack(current, (unsigned long *) regs->gpr[1]);
500         if (!user_mode(regs))
501                 show_instructions(regs);
502 }
503
504 void exit_thread(void)
505 {
506         discard_lazy_cpu_state();
507 }
508
509 void flush_thread(void)
510 {
511 #ifdef CONFIG_PPC64
512         struct thread_info *t = current_thread_info();
513
514         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
515                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
516                 if (test_ti_thread_flag(t, TIF_32BIT))
517                         clear_ti_thread_flag(t, TIF_32BIT);
518                 else
519                         set_ti_thread_flag(t, TIF_32BIT);
520         }
521 #endif
522
523         discard_lazy_cpu_state();
524
525         if (current->thread.dabr) {
526                 current->thread.dabr = 0;
527                 set_dabr(0);
528         }
529 }
530
531 void
532 release_thread(struct task_struct *t)
533 {
534 }
535
536 /*
537  * This gets called before we allocate a new thread and copy
538  * the current task into it.
539  */
540 void prepare_to_copy(struct task_struct *tsk)
541 {
542         flush_fp_to_thread(current);
543         flush_altivec_to_thread(current);
544         flush_vsx_to_thread(current);
545         flush_spe_to_thread(current);
546 }
547
548 /*
549  * Copy a thread..
550  */
551 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
552                 unsigned long unused, struct task_struct *p,
553                 struct pt_regs *regs)
554 {
555         struct pt_regs *childregs, *kregs;
556         extern void ret_from_fork(void);
557         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
558
559         CHECK_FULL_REGS(regs);
560         /* Copy registers */
561         sp -= sizeof(struct pt_regs);
562         childregs = (struct pt_regs *) sp;
563         *childregs = *regs;
564         if ((childregs->msr & MSR_PR) == 0) {
565                 /* for kernel thread, set `current' and stackptr in new task */
566                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
567 #ifdef CONFIG_PPC32
568                 childregs->gpr[2] = (unsigned long) p;
569 #else
570                 clear_tsk_thread_flag(p, TIF_32BIT);
571 #endif
572                 p->thread.regs = NULL;  /* no user register state */
573         } else {
574                 childregs->gpr[1] = usp;
575                 p->thread.regs = childregs;
576                 if (clone_flags & CLONE_SETTLS) {
577 #ifdef CONFIG_PPC64
578                         if (!test_thread_flag(TIF_32BIT))
579                                 childregs->gpr[13] = childregs->gpr[6];
580                         else
581 #endif
582                                 childregs->gpr[2] = childregs->gpr[6];
583                 }
584         }
585         childregs->gpr[3] = 0;  /* Result from fork() */
586         sp -= STACK_FRAME_OVERHEAD;
587
588         /*
589          * The way this works is that at some point in the future
590          * some task will call _switch to switch to the new task.
591          * That will pop off the stack frame created below and start
592          * the new task running at ret_from_fork.  The new task will
593          * do some house keeping and then return from the fork or clone
594          * system call, using the stack frame created above.
595          */
596         sp -= sizeof(struct pt_regs);
597         kregs = (struct pt_regs *) sp;
598         sp -= STACK_FRAME_OVERHEAD;
599         p->thread.ksp = sp;
600         p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
601                                 _ALIGN_UP(sizeof(struct thread_info), 16);
602
603 #ifdef CONFIG_PPC64
604         if (cpu_has_feature(CPU_FTR_SLB)) {
605                 unsigned long sp_vsid;
606                 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
607
608                 if (cpu_has_feature(CPU_FTR_1T_SEGMENT))
609                         sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
610                                 << SLB_VSID_SHIFT_1T;
611                 else
612                         sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
613                                 << SLB_VSID_SHIFT;
614                 sp_vsid |= SLB_VSID_KERNEL | llp;
615                 p->thread.ksp_vsid = sp_vsid;
616         }
617
618         /*
619          * The PPC64 ABI makes use of a TOC to contain function 
620          * pointers.  The function (ret_from_except) is actually a pointer
621          * to the TOC entry.  The first entry is a pointer to the actual
622          * function.
623          */
624         kregs->nip = *((unsigned long *)ret_from_fork);
625 #else
626         kregs->nip = (unsigned long)ret_from_fork;
627 #endif
628
629         return 0;
630 }
631
632 /*
633  * Set up a thread for executing a new program
634  */
635 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
636 {
637 #ifdef CONFIG_PPC64
638         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
639 #endif
640
641         set_fs(USER_DS);
642
643         /*
644          * If we exec out of a kernel thread then thread.regs will not be
645          * set.  Do it now.
646          */
647         if (!current->thread.regs) {
648                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
649                 current->thread.regs = regs - 1;
650         }
651
652         memset(regs->gpr, 0, sizeof(regs->gpr));
653         regs->ctr = 0;
654         regs->link = 0;
655         regs->xer = 0;
656         regs->ccr = 0;
657         regs->gpr[1] = sp;
658
659         /*
660          * We have just cleared all the nonvolatile GPRs, so make
661          * FULL_REGS(regs) return true.  This is necessary to allow
662          * ptrace to examine the thread immediately after exec.
663          */
664         regs->trap &= ~1UL;
665
666 #ifdef CONFIG_PPC32
667         regs->mq = 0;
668         regs->nip = start;
669         regs->msr = MSR_USER;
670 #else
671         if (!test_thread_flag(TIF_32BIT)) {
672                 unsigned long entry, toc;
673
674                 /* start is a relocated pointer to the function descriptor for
675                  * the elf _start routine.  The first entry in the function
676                  * descriptor is the entry address of _start and the second
677                  * entry is the TOC value we need to use.
678                  */
679                 __get_user(entry, (unsigned long __user *)start);
680                 __get_user(toc, (unsigned long __user *)start+1);
681
682                 /* Check whether the e_entry function descriptor entries
683                  * need to be relocated before we can use them.
684                  */
685                 if (load_addr != 0) {
686                         entry += load_addr;
687                         toc   += load_addr;
688                 }
689                 regs->nip = entry;
690                 regs->gpr[2] = toc;
691                 regs->msr = MSR_USER64;
692         } else {
693                 regs->nip = start;
694                 regs->gpr[2] = 0;
695                 regs->msr = MSR_USER32;
696         }
697 #endif
698
699         discard_lazy_cpu_state();
700 #ifdef CONFIG_VSX
701         current->thread.used_vsr = 0;
702 #endif
703         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
704         current->thread.fpscr.val = 0;
705 #ifdef CONFIG_ALTIVEC
706         memset(current->thread.vr, 0, sizeof(current->thread.vr));
707         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
708         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
709         current->thread.vrsave = 0;
710         current->thread.used_vr = 0;
711 #endif /* CONFIG_ALTIVEC */
712 #ifdef CONFIG_SPE
713         memset(current->thread.evr, 0, sizeof(current->thread.evr));
714         current->thread.acc = 0;
715         current->thread.spefscr = 0;
716         current->thread.used_spe = 0;
717 #endif /* CONFIG_SPE */
718 }
719
720 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
721                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
722
723 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
724 {
725         struct pt_regs *regs = tsk->thread.regs;
726
727         /* This is a bit hairy.  If we are an SPE enabled  processor
728          * (have embedded fp) we store the IEEE exception enable flags in
729          * fpexc_mode.  fpexc_mode is also used for setting FP exception
730          * mode (asyn, precise, disabled) for 'Classic' FP. */
731         if (val & PR_FP_EXC_SW_ENABLE) {
732 #ifdef CONFIG_SPE
733                 if (cpu_has_feature(CPU_FTR_SPE)) {
734                         tsk->thread.fpexc_mode = val &
735                                 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
736                         return 0;
737                 } else {
738                         return -EINVAL;
739                 }
740 #else
741                 return -EINVAL;
742 #endif
743         }
744
745         /* on a CONFIG_SPE this does not hurt us.  The bits that
746          * __pack_fe01 use do not overlap with bits used for
747          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
748          * on CONFIG_SPE implementations are reserved so writing to
749          * them does not change anything */
750         if (val > PR_FP_EXC_PRECISE)
751                 return -EINVAL;
752         tsk->thread.fpexc_mode = __pack_fe01(val);
753         if (regs != NULL && (regs->msr & MSR_FP) != 0)
754                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
755                         | tsk->thread.fpexc_mode;
756         return 0;
757 }
758
759 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
760 {
761         unsigned int val;
762
763         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
764 #ifdef CONFIG_SPE
765                 if (cpu_has_feature(CPU_FTR_SPE))
766                         val = tsk->thread.fpexc_mode;
767                 else
768                         return -EINVAL;
769 #else
770                 return -EINVAL;
771 #endif
772         else
773                 val = __unpack_fe01(tsk->thread.fpexc_mode);
774         return put_user(val, (unsigned int __user *) adr);
775 }
776
777 int set_endian(struct task_struct *tsk, unsigned int val)
778 {
779         struct pt_regs *regs = tsk->thread.regs;
780
781         if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
782             (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
783                 return -EINVAL;
784
785         if (regs == NULL)
786                 return -EINVAL;
787
788         if (val == PR_ENDIAN_BIG)
789                 regs->msr &= ~MSR_LE;
790         else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
791                 regs->msr |= MSR_LE;
792         else
793                 return -EINVAL;
794
795         return 0;
796 }
797
798 int get_endian(struct task_struct *tsk, unsigned long adr)
799 {
800         struct pt_regs *regs = tsk->thread.regs;
801         unsigned int val;
802
803         if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
804             !cpu_has_feature(CPU_FTR_REAL_LE))
805                 return -EINVAL;
806
807         if (regs == NULL)
808                 return -EINVAL;
809
810         if (regs->msr & MSR_LE) {
811                 if (cpu_has_feature(CPU_FTR_REAL_LE))
812                         val = PR_ENDIAN_LITTLE;
813                 else
814                         val = PR_ENDIAN_PPC_LITTLE;
815         } else
816                 val = PR_ENDIAN_BIG;
817
818         return put_user(val, (unsigned int __user *)adr);
819 }
820
821 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
822 {
823         tsk->thread.align_ctl = val;
824         return 0;
825 }
826
827 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
828 {
829         return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
830 }
831
832 #define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
833
834 int sys_clone(unsigned long clone_flags, unsigned long usp,
835               int __user *parent_tidp, void __user *child_threadptr,
836               int __user *child_tidp, int p6,
837               struct pt_regs *regs)
838 {
839         CHECK_FULL_REGS(regs);
840         if (usp == 0)
841                 usp = regs->gpr[1];     /* stack pointer for child */
842 #ifdef CONFIG_PPC64
843         if (test_thread_flag(TIF_32BIT)) {
844                 parent_tidp = TRUNC_PTR(parent_tidp);
845                 child_tidp = TRUNC_PTR(child_tidp);
846         }
847 #endif
848         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
849 }
850
851 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
852              unsigned long p4, unsigned long p5, unsigned long p6,
853              struct pt_regs *regs)
854 {
855         CHECK_FULL_REGS(regs);
856         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
857 }
858
859 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
860               unsigned long p4, unsigned long p5, unsigned long p6,
861               struct pt_regs *regs)
862 {
863         CHECK_FULL_REGS(regs);
864         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
865                         regs, 0, NULL, NULL);
866 }
867
868 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
869                unsigned long a3, unsigned long a4, unsigned long a5,
870                struct pt_regs *regs)
871 {
872         int error;
873         char *filename;
874
875         filename = getname((char __user *) a0);
876         error = PTR_ERR(filename);
877         if (IS_ERR(filename))
878                 goto out;
879         flush_fp_to_thread(current);
880         flush_altivec_to_thread(current);
881         flush_spe_to_thread(current);
882         error = do_execve(filename, (char __user * __user *) a1,
883                           (char __user * __user *) a2, regs);
884         putname(filename);
885 out:
886         return error;
887 }
888
889 #ifdef CONFIG_IRQSTACKS
890 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
891                                   unsigned long nbytes)
892 {
893         unsigned long stack_page;
894         unsigned long cpu = task_cpu(p);
895
896         /*
897          * Avoid crashing if the stack has overflowed and corrupted
898          * task_cpu(p), which is in the thread_info struct.
899          */
900         if (cpu < NR_CPUS && cpu_possible(cpu)) {
901                 stack_page = (unsigned long) hardirq_ctx[cpu];
902                 if (sp >= stack_page + sizeof(struct thread_struct)
903                     && sp <= stack_page + THREAD_SIZE - nbytes)
904                         return 1;
905
906                 stack_page = (unsigned long) softirq_ctx[cpu];
907                 if (sp >= stack_page + sizeof(struct thread_struct)
908                     && sp <= stack_page + THREAD_SIZE - nbytes)
909                         return 1;
910         }
911         return 0;
912 }
913
914 #else
915 #define valid_irq_stack(sp, p, nb)      0
916 #endif /* CONFIG_IRQSTACKS */
917
918 int validate_sp(unsigned long sp, struct task_struct *p,
919                        unsigned long nbytes)
920 {
921         unsigned long stack_page = (unsigned long)task_stack_page(p);
922
923         if (sp >= stack_page + sizeof(struct thread_struct)
924             && sp <= stack_page + THREAD_SIZE - nbytes)
925                 return 1;
926
927         return valid_irq_stack(sp, p, nbytes);
928 }
929
930 EXPORT_SYMBOL(validate_sp);
931
932 unsigned long get_wchan(struct task_struct *p)
933 {
934         unsigned long ip, sp;
935         int count = 0;
936
937         if (!p || p == current || p->state == TASK_RUNNING)
938                 return 0;
939
940         sp = p->thread.ksp;
941         if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
942                 return 0;
943
944         do {
945                 sp = *(unsigned long *)sp;
946                 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
947                         return 0;
948                 if (count > 0) {
949                         ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
950                         if (!in_sched_functions(ip))
951                                 return ip;
952                 }
953         } while (count++ < 16);
954         return 0;
955 }
956
957 static int kstack_depth_to_print = 64;
958
959 void show_stack(struct task_struct *tsk, unsigned long *stack)
960 {
961         unsigned long sp, ip, lr, newsp;
962         int count = 0;
963         int firstframe = 1;
964
965         sp = (unsigned long) stack;
966         if (tsk == NULL)
967                 tsk = current;
968         if (sp == 0) {
969                 if (tsk == current)
970                         asm("mr %0,1" : "=r" (sp));
971                 else
972                         sp = tsk->thread.ksp;
973         }
974
975         lr = 0;
976         printk("Call Trace:\n");
977         do {
978                 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
979                         return;
980
981                 stack = (unsigned long *) sp;
982                 newsp = stack[0];
983                 ip = stack[STACK_FRAME_LR_SAVE];
984                 if (!firstframe || ip != lr) {
985                         printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
986                         if (firstframe)
987                                 printk(" (unreliable)");
988                         printk("\n");
989                 }
990                 firstframe = 0;
991
992                 /*
993                  * See if this is an exception frame.
994                  * We look for the "regshere" marker in the current frame.
995                  */
996                 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE)
997                     && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
998                         struct pt_regs *regs = (struct pt_regs *)
999                                 (sp + STACK_FRAME_OVERHEAD);
1000                         lr = regs->link;
1001                         printk("--- Exception: %lx at %pS\n    LR = %pS\n",
1002                                regs->trap, (void *)regs->nip, (void *)lr);
1003                         firstframe = 1;
1004                 }
1005
1006                 sp = newsp;
1007         } while (count++ < kstack_depth_to_print);
1008 }
1009
1010 void dump_stack(void)
1011 {
1012         show_stack(current, NULL);
1013 }
1014 EXPORT_SYMBOL(dump_stack);
1015
1016 #ifdef CONFIG_PPC64
1017 void ppc64_runlatch_on(void)
1018 {
1019         unsigned long ctrl;
1020
1021         if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) {
1022                 HMT_medium();
1023
1024                 ctrl = mfspr(SPRN_CTRLF);
1025                 ctrl |= CTRL_RUNLATCH;
1026                 mtspr(SPRN_CTRLT, ctrl);
1027
1028                 set_thread_flag(TIF_RUNLATCH);
1029         }
1030 }
1031
1032 void ppc64_runlatch_off(void)
1033 {
1034         unsigned long ctrl;
1035
1036         if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) {
1037                 HMT_medium();
1038
1039                 clear_thread_flag(TIF_RUNLATCH);
1040
1041                 ctrl = mfspr(SPRN_CTRLF);
1042                 ctrl &= ~CTRL_RUNLATCH;
1043                 mtspr(SPRN_CTRLT, ctrl);
1044         }
1045 }
1046 #endif
1047
1048 #if THREAD_SHIFT < PAGE_SHIFT
1049
1050 static struct kmem_cache *thread_info_cache;
1051
1052 struct thread_info *alloc_thread_info(struct task_struct *tsk)
1053 {
1054         struct thread_info *ti;
1055
1056         ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL);
1057         if (unlikely(ti == NULL))
1058                 return NULL;
1059 #ifdef CONFIG_DEBUG_STACK_USAGE
1060         memset(ti, 0, THREAD_SIZE);
1061 #endif
1062         return ti;
1063 }
1064
1065 void free_thread_info(struct thread_info *ti)
1066 {
1067         kmem_cache_free(thread_info_cache, ti);
1068 }
1069
1070 void thread_info_cache_init(void)
1071 {
1072         thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
1073                                               THREAD_SIZE, 0, NULL);
1074         BUG_ON(thread_info_cache == NULL);
1075 }
1076
1077 #endif /* THREAD_SHIFT < PAGE_SHIFT */