Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[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/smp_lock.h>
23 #include <linux/stddef.h>
24 #include <linux/unistd.h>
25 #include <linux/ptrace.h>
26 #include <linux/slab.h>
27 #include <linux/user.h>
28 #include <linux/elf.h>
29 #include <linux/init.h>
30 #include <linux/prctl.h>
31 #include <linux/init_task.h>
32 #include <linux/module.h>
33 #include <linux/kallsyms.h>
34 #include <linux/mqueue.h>
35 #include <linux/hardirq.h>
36 #include <linux/utsname.h>
37
38 #include <asm/pgtable.h>
39 #include <asm/uaccess.h>
40 #include <asm/system.h>
41 #include <asm/io.h>
42 #include <asm/processor.h>
43 #include <asm/mmu.h>
44 #include <asm/prom.h>
45 #include <asm/machdep.h>
46 #include <asm/time.h>
47 #include <asm/syscalls.h>
48 #ifdef CONFIG_PPC64
49 #include <asm/firmware.h>
50 #endif
51
52 extern unsigned long _get_SP(void);
53
54 #ifndef CONFIG_SMP
55 struct task_struct *last_task_used_math = NULL;
56 struct task_struct *last_task_used_altivec = 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(current);
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 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
109 {
110         if (!tsk->thread.regs)
111                 return 0;
112         flush_fp_to_thread(current);
113
114         memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
115
116         return 1;
117 }
118
119 #ifdef CONFIG_ALTIVEC
120 void enable_kernel_altivec(void)
121 {
122         WARN_ON(preemptible());
123
124 #ifdef CONFIG_SMP
125         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
126                 giveup_altivec(current);
127         else
128                 giveup_altivec(NULL);   /* just enable AltiVec for kernel - force */
129 #else
130         giveup_altivec(last_task_used_altivec);
131 #endif /* CONFIG_SMP */
132 }
133 EXPORT_SYMBOL(enable_kernel_altivec);
134
135 /*
136  * Make sure the VMX/Altivec register state in the
137  * the thread_struct is up to date for task tsk.
138  */
139 void flush_altivec_to_thread(struct task_struct *tsk)
140 {
141         if (tsk->thread.regs) {
142                 preempt_disable();
143                 if (tsk->thread.regs->msr & MSR_VEC) {
144 #ifdef CONFIG_SMP
145                         BUG_ON(tsk != current);
146 #endif
147                         giveup_altivec(current);
148                 }
149                 preempt_enable();
150         }
151 }
152
153 int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
154 {
155         flush_altivec_to_thread(current);
156         memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
157         return 1;
158 }
159 #endif /* CONFIG_ALTIVEC */
160
161 #ifdef CONFIG_SPE
162
163 void enable_kernel_spe(void)
164 {
165         WARN_ON(preemptible());
166
167 #ifdef CONFIG_SMP
168         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
169                 giveup_spe(current);
170         else
171                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
172 #else
173         giveup_spe(last_task_used_spe);
174 #endif /* __SMP __ */
175 }
176 EXPORT_SYMBOL(enable_kernel_spe);
177
178 void flush_spe_to_thread(struct task_struct *tsk)
179 {
180         if (tsk->thread.regs) {
181                 preempt_disable();
182                 if (tsk->thread.regs->msr & MSR_SPE) {
183 #ifdef CONFIG_SMP
184                         BUG_ON(tsk != current);
185 #endif
186                         giveup_spe(current);
187                 }
188                 preempt_enable();
189         }
190 }
191
192 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
193 {
194         flush_spe_to_thread(current);
195         /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
196         memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
197         return 1;
198 }
199 #endif /* CONFIG_SPE */
200
201 #ifndef CONFIG_SMP
202 /*
203  * If we are doing lazy switching of CPU state (FP, altivec or SPE),
204  * and the current task has some state, discard it.
205  */
206 void discard_lazy_cpu_state(void)
207 {
208         preempt_disable();
209         if (last_task_used_math == current)
210                 last_task_used_math = NULL;
211 #ifdef CONFIG_ALTIVEC
212         if (last_task_used_altivec == current)
213                 last_task_used_altivec = NULL;
214 #endif /* CONFIG_ALTIVEC */
215 #ifdef CONFIG_SPE
216         if (last_task_used_spe == current)
217                 last_task_used_spe = NULL;
218 #endif
219         preempt_enable();
220 }
221 #endif /* CONFIG_SMP */
222
223 #ifdef CONFIG_PPC_MERGE         /* XXX for now */
224 int set_dabr(unsigned long dabr)
225 {
226         if (ppc_md.set_dabr)
227                 return ppc_md.set_dabr(dabr);
228
229         mtspr(SPRN_DABR, dabr);
230         return 0;
231 }
232 #endif
233
234 #ifdef CONFIG_PPC64
235 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
236 static DEFINE_PER_CPU(unsigned long, current_dabr);
237 #endif
238
239 struct task_struct *__switch_to(struct task_struct *prev,
240         struct task_struct *new)
241 {
242         struct thread_struct *new_thread, *old_thread;
243         unsigned long flags;
244         struct task_struct *last;
245
246 #ifdef CONFIG_SMP
247         /* avoid complexity of lazy save/restore of fpu
248          * by just saving it every time we switch out if
249          * this task used the fpu during the last quantum.
250          *
251          * If it tries to use the fpu again, it'll trap and
252          * reload its fp regs.  So we don't have to do a restore
253          * every switch, just a save.
254          *  -- Cort
255          */
256         if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
257                 giveup_fpu(prev);
258 #ifdef CONFIG_ALTIVEC
259         /*
260          * If the previous thread used altivec in the last quantum
261          * (thus changing altivec regs) then save them.
262          * We used to check the VRSAVE register but not all apps
263          * set it, so we don't rely on it now (and in fact we need
264          * to save & restore VSCR even if VRSAVE == 0).  -- paulus
265          *
266          * On SMP we always save/restore altivec regs just to avoid the
267          * complexity of changing processors.
268          *  -- Cort
269          */
270         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
271                 giveup_altivec(prev);
272 #endif /* CONFIG_ALTIVEC */
273 #ifdef CONFIG_SPE
274         /*
275          * If the previous thread used spe in the last quantum
276          * (thus changing spe regs) then save them.
277          *
278          * On SMP we always save/restore spe regs just to avoid the
279          * complexity of changing processors.
280          */
281         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
282                 giveup_spe(prev);
283 #endif /* CONFIG_SPE */
284
285 #else  /* CONFIG_SMP */
286 #ifdef CONFIG_ALTIVEC
287         /* Avoid the trap.  On smp this this never happens since
288          * we don't set last_task_used_altivec -- Cort
289          */
290         if (new->thread.regs && last_task_used_altivec == new)
291                 new->thread.regs->msr |= MSR_VEC;
292 #endif /* CONFIG_ALTIVEC */
293 #ifdef CONFIG_SPE
294         /* Avoid the trap.  On smp this this never happens since
295          * we don't set last_task_used_spe
296          */
297         if (new->thread.regs && last_task_used_spe == new)
298                 new->thread.regs->msr |= MSR_SPE;
299 #endif /* CONFIG_SPE */
300
301 #endif /* CONFIG_SMP */
302
303 #ifdef CONFIG_PPC64     /* for now */
304         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
305                 set_dabr(new->thread.dabr);
306                 __get_cpu_var(current_dabr) = new->thread.dabr;
307         }
308 #endif /* CONFIG_PPC64 */
309
310         new_thread = &new->thread;
311         old_thread = &current->thread;
312
313 #ifdef CONFIG_PPC64
314         /*
315          * Collect processor utilization data per process
316          */
317         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
318                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
319                 long unsigned start_tb, current_tb;
320                 start_tb = old_thread->start_tb;
321                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
322                 old_thread->accum_tb += (current_tb - start_tb);
323                 new_thread->start_tb = current_tb;
324         }
325 #endif
326
327         local_irq_save(flags);
328
329         account_system_vtime(current);
330         account_process_vtime(current);
331         calculate_steal_time();
332
333         last = _switch(old_thread, new_thread);
334
335         local_irq_restore(flags);
336
337         return last;
338 }
339
340 static int instructions_to_print = 16;
341
342 static void show_instructions(struct pt_regs *regs)
343 {
344         int i;
345         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
346                         sizeof(int));
347
348         printk("Instruction dump:");
349
350         for (i = 0; i < instructions_to_print; i++) {
351                 int instr;
352
353                 if (!(i % 8))
354                         printk("\n");
355
356                 /* We use __get_user here *only* to avoid an OOPS on a
357                  * bad address because the pc *should* only be a
358                  * kernel address.
359                  */
360                 if (!__kernel_text_address(pc) ||
361                      __get_user(instr, (unsigned int __user *)pc)) {
362                         printk("XXXXXXXX ");
363                 } else {
364                         if (regs->nip == pc)
365                                 printk("<%08x> ", instr);
366                         else
367                                 printk("%08x ", instr);
368                 }
369
370                 pc += sizeof(int);
371         }
372
373         printk("\n");
374 }
375
376 static struct regbit {
377         unsigned long bit;
378         const char *name;
379 } msr_bits[] = {
380         {MSR_EE,        "EE"},
381         {MSR_PR,        "PR"},
382         {MSR_FP,        "FP"},
383         {MSR_ME,        "ME"},
384         {MSR_IR,        "IR"},
385         {MSR_DR,        "DR"},
386         {0,             NULL}
387 };
388
389 static void printbits(unsigned long val, struct regbit *bits)
390 {
391         const char *sep = "";
392
393         printk("<");
394         for (; bits->bit; ++bits)
395                 if (val & bits->bit) {
396                         printk("%s%s", sep, bits->name);
397                         sep = ",";
398                 }
399         printk(">");
400 }
401
402 #ifdef CONFIG_PPC64
403 #define REG             "%016lx"
404 #define REGS_PER_LINE   4
405 #define LAST_VOLATILE   13
406 #else
407 #define REG             "%08lx"
408 #define REGS_PER_LINE   8
409 #define LAST_VOLATILE   12
410 #endif
411
412 void show_regs(struct pt_regs * regs)
413 {
414         int i, trap;
415
416         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
417                regs->nip, regs->link, regs->ctr);
418         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
419                regs, regs->trap, print_tainted(), init_utsname()->release);
420         printk("MSR: "REG" ", regs->msr);
421         printbits(regs->msr, msr_bits);
422         printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
423         trap = TRAP(regs);
424         if (trap == 0x300 || trap == 0x600)
425                 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
426         printk("TASK = %p[%d] '%s' THREAD: %p",
427                current, current->pid, current->comm, task_thread_info(current));
428
429 #ifdef CONFIG_SMP
430         printk(" CPU: %d", smp_processor_id());
431 #endif /* CONFIG_SMP */
432
433         for (i = 0;  i < 32;  i++) {
434                 if ((i % REGS_PER_LINE) == 0)
435                         printk("\n" KERN_INFO "GPR%02d: ", i);
436                 printk(REG " ", regs->gpr[i]);
437                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
438                         break;
439         }
440         printk("\n");
441 #ifdef CONFIG_KALLSYMS
442         /*
443          * Lookup NIP late so we have the best change of getting the
444          * above info out without failing
445          */
446         printk("NIP ["REG"] ", regs->nip);
447         print_symbol("%s\n", regs->nip);
448         printk("LR ["REG"] ", regs->link);
449         print_symbol("%s\n", regs->link);
450 #endif
451         show_stack(current, (unsigned long *) regs->gpr[1]);
452         if (!user_mode(regs))
453                 show_instructions(regs);
454 }
455
456 void exit_thread(void)
457 {
458         discard_lazy_cpu_state();
459 }
460
461 void flush_thread(void)
462 {
463 #ifdef CONFIG_PPC64
464         struct thread_info *t = current_thread_info();
465
466         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
467                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
468                 if (test_ti_thread_flag(t, TIF_32BIT))
469                         clear_ti_thread_flag(t, TIF_32BIT);
470                 else
471                         set_ti_thread_flag(t, TIF_32BIT);
472         }
473 #endif
474
475         discard_lazy_cpu_state();
476
477 #ifdef CONFIG_PPC64     /* for now */
478         if (current->thread.dabr) {
479                 current->thread.dabr = 0;
480                 set_dabr(0);
481         }
482 #endif
483 }
484
485 void
486 release_thread(struct task_struct *t)
487 {
488 }
489
490 /*
491  * This gets called before we allocate a new thread and copy
492  * the current task into it.
493  */
494 void prepare_to_copy(struct task_struct *tsk)
495 {
496         flush_fp_to_thread(current);
497         flush_altivec_to_thread(current);
498         flush_spe_to_thread(current);
499 }
500
501 /*
502  * Copy a thread..
503  */
504 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
505                 unsigned long unused, struct task_struct *p,
506                 struct pt_regs *regs)
507 {
508         struct pt_regs *childregs, *kregs;
509         extern void ret_from_fork(void);
510         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
511
512         CHECK_FULL_REGS(regs);
513         /* Copy registers */
514         sp -= sizeof(struct pt_regs);
515         childregs = (struct pt_regs *) sp;
516         *childregs = *regs;
517         if ((childregs->msr & MSR_PR) == 0) {
518                 /* for kernel thread, set `current' and stackptr in new task */
519                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
520 #ifdef CONFIG_PPC32
521                 childregs->gpr[2] = (unsigned long) p;
522 #else
523                 clear_tsk_thread_flag(p, TIF_32BIT);
524 #endif
525                 p->thread.regs = NULL;  /* no user register state */
526         } else {
527                 childregs->gpr[1] = usp;
528                 p->thread.regs = childregs;
529                 if (clone_flags & CLONE_SETTLS) {
530 #ifdef CONFIG_PPC64
531                         if (!test_thread_flag(TIF_32BIT))
532                                 childregs->gpr[13] = childregs->gpr[6];
533                         else
534 #endif
535                                 childregs->gpr[2] = childregs->gpr[6];
536                 }
537         }
538         childregs->gpr[3] = 0;  /* Result from fork() */
539         sp -= STACK_FRAME_OVERHEAD;
540
541         /*
542          * The way this works is that at some point in the future
543          * some task will call _switch to switch to the new task.
544          * That will pop off the stack frame created below and start
545          * the new task running at ret_from_fork.  The new task will
546          * do some house keeping and then return from the fork or clone
547          * system call, using the stack frame created above.
548          */
549         sp -= sizeof(struct pt_regs);
550         kregs = (struct pt_regs *) sp;
551         sp -= STACK_FRAME_OVERHEAD;
552         p->thread.ksp = sp;
553
554 #ifdef CONFIG_PPC64
555         if (cpu_has_feature(CPU_FTR_SLB)) {
556                 unsigned long sp_vsid = get_kernel_vsid(sp);
557                 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
558
559                 sp_vsid <<= SLB_VSID_SHIFT;
560                 sp_vsid |= SLB_VSID_KERNEL | llp;
561                 p->thread.ksp_vsid = sp_vsid;
562         }
563
564         /*
565          * The PPC64 ABI makes use of a TOC to contain function 
566          * pointers.  The function (ret_from_except) is actually a pointer
567          * to the TOC entry.  The first entry is a pointer to the actual
568          * function.
569          */
570         kregs->nip = *((unsigned long *)ret_from_fork);
571 #else
572         kregs->nip = (unsigned long)ret_from_fork;
573 #endif
574
575         return 0;
576 }
577
578 /*
579  * Set up a thread for executing a new program
580  */
581 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
582 {
583 #ifdef CONFIG_PPC64
584         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
585 #endif
586
587         set_fs(USER_DS);
588
589         /*
590          * If we exec out of a kernel thread then thread.regs will not be
591          * set.  Do it now.
592          */
593         if (!current->thread.regs) {
594                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
595                 current->thread.regs = regs - 1;
596         }
597
598         memset(regs->gpr, 0, sizeof(regs->gpr));
599         regs->ctr = 0;
600         regs->link = 0;
601         regs->xer = 0;
602         regs->ccr = 0;
603         regs->gpr[1] = sp;
604
605 #ifdef CONFIG_PPC32
606         regs->mq = 0;
607         regs->nip = start;
608         regs->msr = MSR_USER;
609 #else
610         if (!test_thread_flag(TIF_32BIT)) {
611                 unsigned long entry, toc;
612
613                 /* start is a relocated pointer to the function descriptor for
614                  * the elf _start routine.  The first entry in the function
615                  * descriptor is the entry address of _start and the second
616                  * entry is the TOC value we need to use.
617                  */
618                 __get_user(entry, (unsigned long __user *)start);
619                 __get_user(toc, (unsigned long __user *)start+1);
620
621                 /* Check whether the e_entry function descriptor entries
622                  * need to be relocated before we can use them.
623                  */
624                 if (load_addr != 0) {
625                         entry += load_addr;
626                         toc   += load_addr;
627                 }
628                 regs->nip = entry;
629                 regs->gpr[2] = toc;
630                 regs->msr = MSR_USER64;
631         } else {
632                 regs->nip = start;
633                 regs->gpr[2] = 0;
634                 regs->msr = MSR_USER32;
635         }
636 #endif
637
638         discard_lazy_cpu_state();
639         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
640         current->thread.fpscr.val = 0;
641 #ifdef CONFIG_ALTIVEC
642         memset(current->thread.vr, 0, sizeof(current->thread.vr));
643         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
644         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
645         current->thread.vrsave = 0;
646         current->thread.used_vr = 0;
647 #endif /* CONFIG_ALTIVEC */
648 #ifdef CONFIG_SPE
649         memset(current->thread.evr, 0, sizeof(current->thread.evr));
650         current->thread.acc = 0;
651         current->thread.spefscr = 0;
652         current->thread.used_spe = 0;
653 #endif /* CONFIG_SPE */
654 }
655
656 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
657                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
658
659 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
660 {
661         struct pt_regs *regs = tsk->thread.regs;
662
663         /* This is a bit hairy.  If we are an SPE enabled  processor
664          * (have embedded fp) we store the IEEE exception enable flags in
665          * fpexc_mode.  fpexc_mode is also used for setting FP exception
666          * mode (asyn, precise, disabled) for 'Classic' FP. */
667         if (val & PR_FP_EXC_SW_ENABLE) {
668 #ifdef CONFIG_SPE
669                 tsk->thread.fpexc_mode = val &
670                         (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
671                 return 0;
672 #else
673                 return -EINVAL;
674 #endif
675         }
676
677         /* on a CONFIG_SPE this does not hurt us.  The bits that
678          * __pack_fe01 use do not overlap with bits used for
679          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
680          * on CONFIG_SPE implementations are reserved so writing to
681          * them does not change anything */
682         if (val > PR_FP_EXC_PRECISE)
683                 return -EINVAL;
684         tsk->thread.fpexc_mode = __pack_fe01(val);
685         if (regs != NULL && (regs->msr & MSR_FP) != 0)
686                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
687                         | tsk->thread.fpexc_mode;
688         return 0;
689 }
690
691 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
692 {
693         unsigned int val;
694
695         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
696 #ifdef CONFIG_SPE
697                 val = tsk->thread.fpexc_mode;
698 #else
699                 return -EINVAL;
700 #endif
701         else
702                 val = __unpack_fe01(tsk->thread.fpexc_mode);
703         return put_user(val, (unsigned int __user *) adr);
704 }
705
706 int set_endian(struct task_struct *tsk, unsigned int val)
707 {
708         struct pt_regs *regs = tsk->thread.regs;
709
710         if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
711             (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
712                 return -EINVAL;
713
714         if (regs == NULL)
715                 return -EINVAL;
716
717         if (val == PR_ENDIAN_BIG)
718                 regs->msr &= ~MSR_LE;
719         else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
720                 regs->msr |= MSR_LE;
721         else
722                 return -EINVAL;
723
724         return 0;
725 }
726
727 int get_endian(struct task_struct *tsk, unsigned long adr)
728 {
729         struct pt_regs *regs = tsk->thread.regs;
730         unsigned int val;
731
732         if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
733             !cpu_has_feature(CPU_FTR_REAL_LE))
734                 return -EINVAL;
735
736         if (regs == NULL)
737                 return -EINVAL;
738
739         if (regs->msr & MSR_LE) {
740                 if (cpu_has_feature(CPU_FTR_REAL_LE))
741                         val = PR_ENDIAN_LITTLE;
742                 else
743                         val = PR_ENDIAN_PPC_LITTLE;
744         } else
745                 val = PR_ENDIAN_BIG;
746
747         return put_user(val, (unsigned int __user *)adr);
748 }
749
750 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
751 {
752         tsk->thread.align_ctl = val;
753         return 0;
754 }
755
756 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
757 {
758         return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
759 }
760
761 #define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
762
763 int sys_clone(unsigned long clone_flags, unsigned long usp,
764               int __user *parent_tidp, void __user *child_threadptr,
765               int __user *child_tidp, int p6,
766               struct pt_regs *regs)
767 {
768         CHECK_FULL_REGS(regs);
769         if (usp == 0)
770                 usp = regs->gpr[1];     /* stack pointer for child */
771 #ifdef CONFIG_PPC64
772         if (test_thread_flag(TIF_32BIT)) {
773                 parent_tidp = TRUNC_PTR(parent_tidp);
774                 child_tidp = TRUNC_PTR(child_tidp);
775         }
776 #endif
777         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
778 }
779
780 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
781              unsigned long p4, unsigned long p5, unsigned long p6,
782              struct pt_regs *regs)
783 {
784         CHECK_FULL_REGS(regs);
785         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
786 }
787
788 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
789               unsigned long p4, unsigned long p5, unsigned long p6,
790               struct pt_regs *regs)
791 {
792         CHECK_FULL_REGS(regs);
793         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
794                         regs, 0, NULL, NULL);
795 }
796
797 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
798                unsigned long a3, unsigned long a4, unsigned long a5,
799                struct pt_regs *regs)
800 {
801         int error;
802         char *filename;
803
804         filename = getname((char __user *) a0);
805         error = PTR_ERR(filename);
806         if (IS_ERR(filename))
807                 goto out;
808         flush_fp_to_thread(current);
809         flush_altivec_to_thread(current);
810         flush_spe_to_thread(current);
811         error = do_execve(filename, (char __user * __user *) a1,
812                           (char __user * __user *) a2, regs);
813         if (error == 0) {
814                 task_lock(current);
815                 current->ptrace &= ~PT_DTRACE;
816                 task_unlock(current);
817         }
818         putname(filename);
819 out:
820         return error;
821 }
822
823 #ifdef CONFIG_IRQSTACKS
824 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
825                                   unsigned long nbytes)
826 {
827         unsigned long stack_page;
828         unsigned long cpu = task_cpu(p);
829
830         /*
831          * Avoid crashing if the stack has overflowed and corrupted
832          * task_cpu(p), which is in the thread_info struct.
833          */
834         if (cpu < NR_CPUS && cpu_possible(cpu)) {
835                 stack_page = (unsigned long) hardirq_ctx[cpu];
836                 if (sp >= stack_page + sizeof(struct thread_struct)
837                     && sp <= stack_page + THREAD_SIZE - nbytes)
838                         return 1;
839
840                 stack_page = (unsigned long) softirq_ctx[cpu];
841                 if (sp >= stack_page + sizeof(struct thread_struct)
842                     && sp <= stack_page + THREAD_SIZE - nbytes)
843                         return 1;
844         }
845         return 0;
846 }
847
848 #else
849 #define valid_irq_stack(sp, p, nb)      0
850 #endif /* CONFIG_IRQSTACKS */
851
852 int validate_sp(unsigned long sp, struct task_struct *p,
853                        unsigned long nbytes)
854 {
855         unsigned long stack_page = (unsigned long)task_stack_page(p);
856
857         if (sp >= stack_page + sizeof(struct thread_struct)
858             && sp <= stack_page + THREAD_SIZE - nbytes)
859                 return 1;
860
861         return valid_irq_stack(sp, p, nbytes);
862 }
863
864 #ifdef CONFIG_PPC64
865 #define MIN_STACK_FRAME 112     /* same as STACK_FRAME_OVERHEAD, in fact */
866 #define FRAME_LR_SAVE   2
867 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
868 #define REGS_MARKER     0x7265677368657265ul
869 #define FRAME_MARKER    12
870 #else
871 #define MIN_STACK_FRAME 16
872 #define FRAME_LR_SAVE   1
873 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
874 #define REGS_MARKER     0x72656773ul
875 #define FRAME_MARKER    2
876 #endif
877
878 EXPORT_SYMBOL(validate_sp);
879
880 unsigned long get_wchan(struct task_struct *p)
881 {
882         unsigned long ip, sp;
883         int count = 0;
884
885         if (!p || p == current || p->state == TASK_RUNNING)
886                 return 0;
887
888         sp = p->thread.ksp;
889         if (!validate_sp(sp, p, MIN_STACK_FRAME))
890                 return 0;
891
892         do {
893                 sp = *(unsigned long *)sp;
894                 if (!validate_sp(sp, p, MIN_STACK_FRAME))
895                         return 0;
896                 if (count > 0) {
897                         ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
898                         if (!in_sched_functions(ip))
899                                 return ip;
900                 }
901         } while (count++ < 16);
902         return 0;
903 }
904
905 static int kstack_depth_to_print = 64;
906
907 void show_stack(struct task_struct *tsk, unsigned long *stack)
908 {
909         unsigned long sp, ip, lr, newsp;
910         int count = 0;
911         int firstframe = 1;
912
913         sp = (unsigned long) stack;
914         if (tsk == NULL)
915                 tsk = current;
916         if (sp == 0) {
917                 if (tsk == current)
918                         asm("mr %0,1" : "=r" (sp));
919                 else
920                         sp = tsk->thread.ksp;
921         }
922
923         lr = 0;
924         printk("Call Trace:\n");
925         do {
926                 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
927                         return;
928
929                 stack = (unsigned long *) sp;
930                 newsp = stack[0];
931                 ip = stack[FRAME_LR_SAVE];
932                 if (!firstframe || ip != lr) {
933                         printk("["REG"] ["REG"] ", sp, ip);
934                         print_symbol("%s", ip);
935                         if (firstframe)
936                                 printk(" (unreliable)");
937                         printk("\n");
938                 }
939                 firstframe = 0;
940
941                 /*
942                  * See if this is an exception frame.
943                  * We look for the "regshere" marker in the current frame.
944                  */
945                 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
946                     && stack[FRAME_MARKER] == REGS_MARKER) {
947                         struct pt_regs *regs = (struct pt_regs *)
948                                 (sp + STACK_FRAME_OVERHEAD);
949                         printk("--- Exception: %lx", regs->trap);
950                         print_symbol(" at %s\n", regs->nip);
951                         lr = regs->link;
952                         print_symbol("    LR = %s\n", lr);
953                         firstframe = 1;
954                 }
955
956                 sp = newsp;
957         } while (count++ < kstack_depth_to_print);
958 }
959
960 void dump_stack(void)
961 {
962         show_stack(current, NULL);
963 }
964 EXPORT_SYMBOL(dump_stack);
965
966 #ifdef CONFIG_PPC64
967 void ppc64_runlatch_on(void)
968 {
969         unsigned long ctrl;
970
971         if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) {
972                 HMT_medium();
973
974                 ctrl = mfspr(SPRN_CTRLF);
975                 ctrl |= CTRL_RUNLATCH;
976                 mtspr(SPRN_CTRLT, ctrl);
977
978                 set_thread_flag(TIF_RUNLATCH);
979         }
980 }
981
982 void ppc64_runlatch_off(void)
983 {
984         unsigned long ctrl;
985
986         if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) {
987                 HMT_medium();
988
989                 clear_thread_flag(TIF_RUNLATCH);
990
991                 ctrl = mfspr(SPRN_CTRLF);
992                 ctrl &= ~CTRL_RUNLATCH;
993                 mtspr(SPRN_CTRLT, ctrl);
994         }
995 }
996 #endif