Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
[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_spe = NULL;
57 #endif
58
59 /*
60  * Make sure the floating-point register state in the
61  * the thread_struct is up to date for task tsk.
62  */
63 void flush_fp_to_thread(struct task_struct *tsk)
64 {
65         if (tsk->thread.regs) {
66                 /*
67                  * We need to disable preemption here because if we didn't,
68                  * another process could get scheduled after the regs->msr
69                  * test but before we have finished saving the FP registers
70                  * to the thread_struct.  That process could take over the
71                  * FPU, and then when we get scheduled again we would store
72                  * bogus values for the remaining FP registers.
73                  */
74                 preempt_disable();
75                 if (tsk->thread.regs->msr & MSR_FP) {
76 #ifdef CONFIG_SMP
77                         /*
78                          * This should only ever be called for current or
79                          * for a stopped child process.  Since we save away
80                          * the FP register state on context switch on SMP,
81                          * there is something wrong if a stopped child appears
82                          * to still have its FP state in the CPU registers.
83                          */
84                         BUG_ON(tsk != current);
85 #endif
86                         giveup_fpu(tsk);
87                 }
88                 preempt_enable();
89         }
90 }
91
92 void enable_kernel_fp(void)
93 {
94         WARN_ON(preemptible());
95
96 #ifdef CONFIG_SMP
97         if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
98                 giveup_fpu(current);
99         else
100                 giveup_fpu(NULL);       /* just enables FP for kernel */
101 #else
102         giveup_fpu(last_task_used_math);
103 #endif /* CONFIG_SMP */
104 }
105 EXPORT_SYMBOL(enable_kernel_fp);
106
107 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
108 {
109         if (!tsk->thread.regs)
110                 return 0;
111         flush_fp_to_thread(current);
112
113         memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
114
115         return 1;
116 }
117
118 #ifdef CONFIG_ALTIVEC
119 void enable_kernel_altivec(void)
120 {
121         WARN_ON(preemptible());
122
123 #ifdef CONFIG_SMP
124         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
125                 giveup_altivec(current);
126         else
127                 giveup_altivec(NULL);   /* just enable AltiVec for kernel - force */
128 #else
129         giveup_altivec(last_task_used_altivec);
130 #endif /* CONFIG_SMP */
131 }
132 EXPORT_SYMBOL(enable_kernel_altivec);
133
134 /*
135  * Make sure the VMX/Altivec register state in the
136  * the thread_struct is up to date for task tsk.
137  */
138 void flush_altivec_to_thread(struct task_struct *tsk)
139 {
140         if (tsk->thread.regs) {
141                 preempt_disable();
142                 if (tsk->thread.regs->msr & MSR_VEC) {
143 #ifdef CONFIG_SMP
144                         BUG_ON(tsk != current);
145 #endif
146                         giveup_altivec(tsk);
147                 }
148                 preempt_enable();
149         }
150 }
151
152 int dump_task_altivec(struct task_struct *tsk, elf_vrregset_t *vrregs)
153 {
154         /* ELF_NVRREG includes the VSCR and VRSAVE which we need to save
155          * separately, see below */
156         const int nregs = ELF_NVRREG - 2;
157         elf_vrreg_t *reg;
158         u32 *dest;
159
160         if (tsk == current)
161                 flush_altivec_to_thread(tsk);
162
163         reg = (elf_vrreg_t *)vrregs;
164
165         /* copy the 32 vr registers */
166         memcpy(reg, &tsk->thread.vr[0], nregs * sizeof(*reg));
167         reg += nregs;
168
169         /* copy the vscr */
170         memcpy(reg, &tsk->thread.vscr, sizeof(*reg));
171         reg++;
172
173         /* vrsave is stored in the high 32bit slot of the final 128bits */
174         memset(reg, 0, sizeof(*reg));
175         dest = (u32 *)reg;
176         *dest = tsk->thread.vrsave;
177
178         return 1;
179 }
180 #endif /* CONFIG_ALTIVEC */
181
182 #ifdef CONFIG_SPE
183
184 void enable_kernel_spe(void)
185 {
186         WARN_ON(preemptible());
187
188 #ifdef CONFIG_SMP
189         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
190                 giveup_spe(current);
191         else
192                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
193 #else
194         giveup_spe(last_task_used_spe);
195 #endif /* __SMP __ */
196 }
197 EXPORT_SYMBOL(enable_kernel_spe);
198
199 void flush_spe_to_thread(struct task_struct *tsk)
200 {
201         if (tsk->thread.regs) {
202                 preempt_disable();
203                 if (tsk->thread.regs->msr & MSR_SPE) {
204 #ifdef CONFIG_SMP
205                         BUG_ON(tsk != current);
206 #endif
207                         giveup_spe(tsk);
208                 }
209                 preempt_enable();
210         }
211 }
212
213 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
214 {
215         flush_spe_to_thread(current);
216         /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
217         memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
218         return 1;
219 }
220 #endif /* CONFIG_SPE */
221
222 #ifndef CONFIG_SMP
223 /*
224  * If we are doing lazy switching of CPU state (FP, altivec or SPE),
225  * and the current task has some state, discard it.
226  */
227 void discard_lazy_cpu_state(void)
228 {
229         preempt_disable();
230         if (last_task_used_math == current)
231                 last_task_used_math = NULL;
232 #ifdef CONFIG_ALTIVEC
233         if (last_task_used_altivec == current)
234                 last_task_used_altivec = NULL;
235 #endif /* CONFIG_ALTIVEC */
236 #ifdef CONFIG_SPE
237         if (last_task_used_spe == current)
238                 last_task_used_spe = NULL;
239 #endif
240         preempt_enable();
241 }
242 #endif /* CONFIG_SMP */
243
244 int set_dabr(unsigned long dabr)
245 {
246 #ifdef CONFIG_PPC_MERGE         /* XXX for now */
247         if (ppc_md.set_dabr)
248                 return ppc_md.set_dabr(dabr);
249 #endif
250
251         /* XXX should we have a CPU_FTR_HAS_DABR ? */
252 #if defined(CONFIG_PPC64) || defined(CONFIG_6xx)
253         mtspr(SPRN_DABR, dabr);
254 #endif
255         return 0;
256 }
257
258 #ifdef CONFIG_PPC64
259 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
260 #endif
261
262 static DEFINE_PER_CPU(unsigned long, current_dabr);
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_SPE
299         /*
300          * If the previous thread used spe in the last quantum
301          * (thus changing spe regs) then save them.
302          *
303          * On SMP we always save/restore spe regs just to avoid the
304          * complexity of changing processors.
305          */
306         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
307                 giveup_spe(prev);
308 #endif /* CONFIG_SPE */
309
310 #else  /* CONFIG_SMP */
311 #ifdef CONFIG_ALTIVEC
312         /* Avoid the trap.  On smp this this never happens since
313          * we don't set last_task_used_altivec -- Cort
314          */
315         if (new->thread.regs && last_task_used_altivec == new)
316                 new->thread.regs->msr |= MSR_VEC;
317 #endif /* CONFIG_ALTIVEC */
318 #ifdef CONFIG_SPE
319         /* Avoid the trap.  On smp this this never happens since
320          * we don't set last_task_used_spe
321          */
322         if (new->thread.regs && last_task_used_spe == new)
323                 new->thread.regs->msr |= MSR_SPE;
324 #endif /* CONFIG_SPE */
325
326 #endif /* CONFIG_SMP */
327
328         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
329                 set_dabr(new->thread.dabr);
330                 __get_cpu_var(current_dabr) = new->thread.dabr;
331         }
332
333         new_thread = &new->thread;
334         old_thread = &current->thread;
335
336 #ifdef CONFIG_PPC64
337         /*
338          * Collect processor utilization data per process
339          */
340         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
341                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
342                 long unsigned start_tb, current_tb;
343                 start_tb = old_thread->start_tb;
344                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
345                 old_thread->accum_tb += (current_tb - start_tb);
346                 new_thread->start_tb = current_tb;
347         }
348 #endif
349
350         local_irq_save(flags);
351
352         account_system_vtime(current);
353         account_process_vtime(current);
354         calculate_steal_time();
355
356         last = _switch(old_thread, new_thread);
357
358         local_irq_restore(flags);
359
360         return last;
361 }
362
363 static int instructions_to_print = 16;
364
365 static void show_instructions(struct pt_regs *regs)
366 {
367         int i;
368         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
369                         sizeof(int));
370
371         printk("Instruction dump:");
372
373         for (i = 0; i < instructions_to_print; i++) {
374                 int instr;
375
376                 if (!(i % 8))
377                         printk("\n");
378
379 #if !defined(CONFIG_BOOKE)
380                 /* If executing with the IMMU off, adjust pc rather
381                  * than print XXXXXXXX.
382                  */
383                 if (!(regs->msr & MSR_IR))
384                         pc = (unsigned long)phys_to_virt(pc);
385 #endif
386
387                 /* We use __get_user here *only* to avoid an OOPS on a
388                  * bad address because the pc *should* only be a
389                  * kernel address.
390                  */
391                 if (!__kernel_text_address(pc) ||
392                      __get_user(instr, (unsigned int __user *)pc)) {
393                         printk("XXXXXXXX ");
394                 } else {
395                         if (regs->nip == pc)
396                                 printk("<%08x> ", instr);
397                         else
398                                 printk("%08x ", instr);
399                 }
400
401                 pc += sizeof(int);
402         }
403
404         printk("\n");
405 }
406
407 static struct regbit {
408         unsigned long bit;
409         const char *name;
410 } msr_bits[] = {
411         {MSR_EE,        "EE"},
412         {MSR_PR,        "PR"},
413         {MSR_FP,        "FP"},
414         {MSR_ME,        "ME"},
415         {MSR_IR,        "IR"},
416         {MSR_DR,        "DR"},
417         {0,             NULL}
418 };
419
420 static void printbits(unsigned long val, struct regbit *bits)
421 {
422         const char *sep = "";
423
424         printk("<");
425         for (; bits->bit; ++bits)
426                 if (val & bits->bit) {
427                         printk("%s%s", sep, bits->name);
428                         sep = ",";
429                 }
430         printk(">");
431 }
432
433 #ifdef CONFIG_PPC64
434 #define REG             "%016lx"
435 #define REGS_PER_LINE   4
436 #define LAST_VOLATILE   13
437 #else
438 #define REG             "%08lx"
439 #define REGS_PER_LINE   8
440 #define LAST_VOLATILE   12
441 #endif
442
443 void show_regs(struct pt_regs * regs)
444 {
445         int i, trap;
446
447         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
448                regs->nip, regs->link, regs->ctr);
449         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
450                regs, regs->trap, print_tainted(), init_utsname()->release);
451         printk("MSR: "REG" ", regs->msr);
452         printbits(regs->msr, msr_bits);
453         printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
454         trap = TRAP(regs);
455         if (trap == 0x300 || trap == 0x600)
456 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
457                 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr);
458 #else
459                 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
460 #endif
461         printk("TASK = %p[%d] '%s' THREAD: %p",
462                current, task_pid_nr(current), current->comm, task_thread_info(current));
463
464 #ifdef CONFIG_SMP
465         printk(" CPU: %d", smp_processor_id());
466 #endif /* CONFIG_SMP */
467
468         for (i = 0;  i < 32;  i++) {
469                 if ((i % REGS_PER_LINE) == 0)
470                         printk("\n" KERN_INFO "GPR%02d: ", i);
471                 printk(REG " ", regs->gpr[i]);
472                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
473                         break;
474         }
475         printk("\n");
476 #ifdef CONFIG_KALLSYMS
477         /*
478          * Lookup NIP late so we have the best change of getting the
479          * above info out without failing
480          */
481         printk("NIP ["REG"] ", regs->nip);
482         print_symbol("%s\n", regs->nip);
483         printk("LR ["REG"] ", regs->link);
484         print_symbol("%s\n", regs->link);
485 #endif
486         show_stack(current, (unsigned long *) regs->gpr[1]);
487         if (!user_mode(regs))
488                 show_instructions(regs);
489 }
490
491 void exit_thread(void)
492 {
493         discard_lazy_cpu_state();
494 }
495
496 void flush_thread(void)
497 {
498 #ifdef CONFIG_PPC64
499         struct thread_info *t = current_thread_info();
500
501         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
502                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
503                 if (test_ti_thread_flag(t, TIF_32BIT))
504                         clear_ti_thread_flag(t, TIF_32BIT);
505                 else
506                         set_ti_thread_flag(t, TIF_32BIT);
507         }
508 #endif
509
510         discard_lazy_cpu_state();
511
512         if (current->thread.dabr) {
513                 current->thread.dabr = 0;
514                 set_dabr(0);
515         }
516 }
517
518 void
519 release_thread(struct task_struct *t)
520 {
521 }
522
523 /*
524  * This gets called before we allocate a new thread and copy
525  * the current task into it.
526  */
527 void prepare_to_copy(struct task_struct *tsk)
528 {
529         flush_fp_to_thread(current);
530         flush_altivec_to_thread(current);
531         flush_spe_to_thread(current);
532 }
533
534 /*
535  * Copy a thread..
536  */
537 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
538                 unsigned long unused, struct task_struct *p,
539                 struct pt_regs *regs)
540 {
541         struct pt_regs *childregs, *kregs;
542         extern void ret_from_fork(void);
543         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
544
545         CHECK_FULL_REGS(regs);
546         /* Copy registers */
547         sp -= sizeof(struct pt_regs);
548         childregs = (struct pt_regs *) sp;
549         *childregs = *regs;
550         if ((childregs->msr & MSR_PR) == 0) {
551                 /* for kernel thread, set `current' and stackptr in new task */
552                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
553 #ifdef CONFIG_PPC32
554                 childregs->gpr[2] = (unsigned long) p;
555 #else
556                 clear_tsk_thread_flag(p, TIF_32BIT);
557 #endif
558                 p->thread.regs = NULL;  /* no user register state */
559         } else {
560                 childregs->gpr[1] = usp;
561                 p->thread.regs = childregs;
562                 if (clone_flags & CLONE_SETTLS) {
563 #ifdef CONFIG_PPC64
564                         if (!test_thread_flag(TIF_32BIT))
565                                 childregs->gpr[13] = childregs->gpr[6];
566                         else
567 #endif
568                                 childregs->gpr[2] = childregs->gpr[6];
569                 }
570         }
571         childregs->gpr[3] = 0;  /* Result from fork() */
572         sp -= STACK_FRAME_OVERHEAD;
573
574         /*
575          * The way this works is that at some point in the future
576          * some task will call _switch to switch to the new task.
577          * That will pop off the stack frame created below and start
578          * the new task running at ret_from_fork.  The new task will
579          * do some house keeping and then return from the fork or clone
580          * system call, using the stack frame created above.
581          */
582         sp -= sizeof(struct pt_regs);
583         kregs = (struct pt_regs *) sp;
584         sp -= STACK_FRAME_OVERHEAD;
585         p->thread.ksp = sp;
586
587 #ifdef CONFIG_PPC64
588         if (cpu_has_feature(CPU_FTR_SLB)) {
589                 unsigned long sp_vsid;
590                 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
591
592                 if (cpu_has_feature(CPU_FTR_1T_SEGMENT))
593                         sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
594                                 << SLB_VSID_SHIFT_1T;
595                 else
596                         sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
597                                 << SLB_VSID_SHIFT;
598                 sp_vsid |= SLB_VSID_KERNEL | llp;
599                 p->thread.ksp_vsid = sp_vsid;
600         }
601
602         /*
603          * The PPC64 ABI makes use of a TOC to contain function 
604          * pointers.  The function (ret_from_except) is actually a pointer
605          * to the TOC entry.  The first entry is a pointer to the actual
606          * function.
607          */
608         kregs->nip = *((unsigned long *)ret_from_fork);
609 #else
610         kregs->nip = (unsigned long)ret_from_fork;
611 #endif
612
613         return 0;
614 }
615
616 /*
617  * Set up a thread for executing a new program
618  */
619 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
620 {
621 #ifdef CONFIG_PPC64
622         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
623 #endif
624
625         set_fs(USER_DS);
626
627         /*
628          * If we exec out of a kernel thread then thread.regs will not be
629          * set.  Do it now.
630          */
631         if (!current->thread.regs) {
632                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
633                 current->thread.regs = regs - 1;
634         }
635
636         memset(regs->gpr, 0, sizeof(regs->gpr));
637         regs->ctr = 0;
638         regs->link = 0;
639         regs->xer = 0;
640         regs->ccr = 0;
641         regs->gpr[1] = sp;
642
643         /*
644          * We have just cleared all the nonvolatile GPRs, so make
645          * FULL_REGS(regs) return true.  This is necessary to allow
646          * ptrace to examine the thread immediately after exec.
647          */
648         regs->trap &= ~1UL;
649
650 #ifdef CONFIG_PPC32
651         regs->mq = 0;
652         regs->nip = start;
653         regs->msr = MSR_USER;
654 #else
655         if (!test_thread_flag(TIF_32BIT)) {
656                 unsigned long entry, toc;
657
658                 /* start is a relocated pointer to the function descriptor for
659                  * the elf _start routine.  The first entry in the function
660                  * descriptor is the entry address of _start and the second
661                  * entry is the TOC value we need to use.
662                  */
663                 __get_user(entry, (unsigned long __user *)start);
664                 __get_user(toc, (unsigned long __user *)start+1);
665
666                 /* Check whether the e_entry function descriptor entries
667                  * need to be relocated before we can use them.
668                  */
669                 if (load_addr != 0) {
670                         entry += load_addr;
671                         toc   += load_addr;
672                 }
673                 regs->nip = entry;
674                 regs->gpr[2] = toc;
675                 regs->msr = MSR_USER64;
676         } else {
677                 regs->nip = start;
678                 regs->gpr[2] = 0;
679                 regs->msr = MSR_USER32;
680         }
681 #endif
682
683         discard_lazy_cpu_state();
684         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
685         current->thread.fpscr.val = 0;
686 #ifdef CONFIG_ALTIVEC
687         memset(current->thread.vr, 0, sizeof(current->thread.vr));
688         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
689         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
690         current->thread.vrsave = 0;
691         current->thread.used_vr = 0;
692 #endif /* CONFIG_ALTIVEC */
693 #ifdef CONFIG_SPE
694         memset(current->thread.evr, 0, sizeof(current->thread.evr));
695         current->thread.acc = 0;
696         current->thread.spefscr = 0;
697         current->thread.used_spe = 0;
698 #endif /* CONFIG_SPE */
699 }
700
701 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
702                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
703
704 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
705 {
706         struct pt_regs *regs = tsk->thread.regs;
707
708         /* This is a bit hairy.  If we are an SPE enabled  processor
709          * (have embedded fp) we store the IEEE exception enable flags in
710          * fpexc_mode.  fpexc_mode is also used for setting FP exception
711          * mode (asyn, precise, disabled) for 'Classic' FP. */
712         if (val & PR_FP_EXC_SW_ENABLE) {
713 #ifdef CONFIG_SPE
714                 if (cpu_has_feature(CPU_FTR_SPE)) {
715                         tsk->thread.fpexc_mode = val &
716                                 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
717                         return 0;
718                 } else {
719                         return -EINVAL;
720                 }
721 #else
722                 return -EINVAL;
723 #endif
724         }
725
726         /* on a CONFIG_SPE this does not hurt us.  The bits that
727          * __pack_fe01 use do not overlap with bits used for
728          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
729          * on CONFIG_SPE implementations are reserved so writing to
730          * them does not change anything */
731         if (val > PR_FP_EXC_PRECISE)
732                 return -EINVAL;
733         tsk->thread.fpexc_mode = __pack_fe01(val);
734         if (regs != NULL && (regs->msr & MSR_FP) != 0)
735                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
736                         | tsk->thread.fpexc_mode;
737         return 0;
738 }
739
740 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
741 {
742         unsigned int val;
743
744         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
745 #ifdef CONFIG_SPE
746                 if (cpu_has_feature(CPU_FTR_SPE))
747                         val = tsk->thread.fpexc_mode;
748                 else
749                         return -EINVAL;
750 #else
751                 return -EINVAL;
752 #endif
753         else
754                 val = __unpack_fe01(tsk->thread.fpexc_mode);
755         return put_user(val, (unsigned int __user *) adr);
756 }
757
758 int set_endian(struct task_struct *tsk, unsigned int val)
759 {
760         struct pt_regs *regs = tsk->thread.regs;
761
762         if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
763             (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
764                 return -EINVAL;
765
766         if (regs == NULL)
767                 return -EINVAL;
768
769         if (val == PR_ENDIAN_BIG)
770                 regs->msr &= ~MSR_LE;
771         else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
772                 regs->msr |= MSR_LE;
773         else
774                 return -EINVAL;
775
776         return 0;
777 }
778
779 int get_endian(struct task_struct *tsk, unsigned long adr)
780 {
781         struct pt_regs *regs = tsk->thread.regs;
782         unsigned int val;
783
784         if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
785             !cpu_has_feature(CPU_FTR_REAL_LE))
786                 return -EINVAL;
787
788         if (regs == NULL)
789                 return -EINVAL;
790
791         if (regs->msr & MSR_LE) {
792                 if (cpu_has_feature(CPU_FTR_REAL_LE))
793                         val = PR_ENDIAN_LITTLE;
794                 else
795                         val = PR_ENDIAN_PPC_LITTLE;
796         } else
797                 val = PR_ENDIAN_BIG;
798
799         return put_user(val, (unsigned int __user *)adr);
800 }
801
802 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
803 {
804         tsk->thread.align_ctl = val;
805         return 0;
806 }
807
808 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
809 {
810         return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
811 }
812
813 #define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
814
815 int sys_clone(unsigned long clone_flags, unsigned long usp,
816               int __user *parent_tidp, void __user *child_threadptr,
817               int __user *child_tidp, int p6,
818               struct pt_regs *regs)
819 {
820         CHECK_FULL_REGS(regs);
821         if (usp == 0)
822                 usp = regs->gpr[1];     /* stack pointer for child */
823 #ifdef CONFIG_PPC64
824         if (test_thread_flag(TIF_32BIT)) {
825                 parent_tidp = TRUNC_PTR(parent_tidp);
826                 child_tidp = TRUNC_PTR(child_tidp);
827         }
828 #endif
829         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
830 }
831
832 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
833              unsigned long p4, unsigned long p5, unsigned long p6,
834              struct pt_regs *regs)
835 {
836         CHECK_FULL_REGS(regs);
837         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
838 }
839
840 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
841               unsigned long p4, unsigned long p5, unsigned long p6,
842               struct pt_regs *regs)
843 {
844         CHECK_FULL_REGS(regs);
845         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
846                         regs, 0, NULL, NULL);
847 }
848
849 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
850                unsigned long a3, unsigned long a4, unsigned long a5,
851                struct pt_regs *regs)
852 {
853         int error;
854         char *filename;
855
856         filename = getname((char __user *) a0);
857         error = PTR_ERR(filename);
858         if (IS_ERR(filename))
859                 goto out;
860         flush_fp_to_thread(current);
861         flush_altivec_to_thread(current);
862         flush_spe_to_thread(current);
863         error = do_execve(filename, (char __user * __user *) a1,
864                           (char __user * __user *) a2, regs);
865         if (error == 0) {
866                 task_lock(current);
867                 current->ptrace &= ~PT_DTRACE;
868                 task_unlock(current);
869         }
870         putname(filename);
871 out:
872         return error;
873 }
874
875 #ifdef CONFIG_IRQSTACKS
876 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
877                                   unsigned long nbytes)
878 {
879         unsigned long stack_page;
880         unsigned long cpu = task_cpu(p);
881
882         /*
883          * Avoid crashing if the stack has overflowed and corrupted
884          * task_cpu(p), which is in the thread_info struct.
885          */
886         if (cpu < NR_CPUS && cpu_possible(cpu)) {
887                 stack_page = (unsigned long) hardirq_ctx[cpu];
888                 if (sp >= stack_page + sizeof(struct thread_struct)
889                     && sp <= stack_page + THREAD_SIZE - nbytes)
890                         return 1;
891
892                 stack_page = (unsigned long) softirq_ctx[cpu];
893                 if (sp >= stack_page + sizeof(struct thread_struct)
894                     && sp <= stack_page + THREAD_SIZE - nbytes)
895                         return 1;
896         }
897         return 0;
898 }
899
900 #else
901 #define valid_irq_stack(sp, p, nb)      0
902 #endif /* CONFIG_IRQSTACKS */
903
904 int validate_sp(unsigned long sp, struct task_struct *p,
905                        unsigned long nbytes)
906 {
907         unsigned long stack_page = (unsigned long)task_stack_page(p);
908
909         if (sp >= stack_page + sizeof(struct thread_struct)
910             && sp <= stack_page + THREAD_SIZE - nbytes)
911                 return 1;
912
913         return valid_irq_stack(sp, p, nbytes);
914 }
915
916 #ifdef CONFIG_PPC64
917 #define MIN_STACK_FRAME 112     /* same as STACK_FRAME_OVERHEAD, in fact */
918 #define FRAME_LR_SAVE   2
919 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
920 #define REGS_MARKER     0x7265677368657265ul
921 #define FRAME_MARKER    12
922 #else
923 #define MIN_STACK_FRAME 16
924 #define FRAME_LR_SAVE   1
925 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
926 #define REGS_MARKER     0x72656773ul
927 #define FRAME_MARKER    2
928 #endif
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, MIN_STACK_FRAME))
942                 return 0;
943
944         do {
945                 sp = *(unsigned long *)sp;
946                 if (!validate_sp(sp, p, MIN_STACK_FRAME))
947                         return 0;
948                 if (count > 0) {
949                         ip = ((unsigned long *)sp)[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, MIN_STACK_FRAME))
979                         return;
980
981                 stack = (unsigned long *) sp;
982                 newsp = stack[0];
983                 ip = stack[FRAME_LR_SAVE];
984                 if (!firstframe || ip != lr) {
985                         printk("["REG"] ["REG"] ", sp, ip);
986                         print_symbol("%s", ip);
987                         if (firstframe)
988                                 printk(" (unreliable)");
989                         printk("\n");
990                 }
991                 firstframe = 0;
992
993                 /*
994                  * See if this is an exception frame.
995                  * We look for the "regshere" marker in the current frame.
996                  */
997                 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
998                     && stack[FRAME_MARKER] == REGS_MARKER) {
999                         struct pt_regs *regs = (struct pt_regs *)
1000                                 (sp + STACK_FRAME_OVERHEAD);
1001                         printk("--- Exception: %lx", regs->trap);
1002                         print_symbol(" at %s\n", regs->nip);
1003                         lr = regs->link;
1004                         print_symbol("    LR = %s\n", lr);
1005                         firstframe = 1;
1006                 }
1007
1008                 sp = newsp;
1009         } while (count++ < kstack_depth_to_print);
1010 }
1011
1012 void dump_stack(void)
1013 {
1014         show_stack(current, NULL);
1015 }
1016 EXPORT_SYMBOL(dump_stack);
1017
1018 #ifdef CONFIG_PPC64
1019 void ppc64_runlatch_on(void)
1020 {
1021         unsigned long ctrl;
1022
1023         if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) {
1024                 HMT_medium();
1025
1026                 ctrl = mfspr(SPRN_CTRLF);
1027                 ctrl |= CTRL_RUNLATCH;
1028                 mtspr(SPRN_CTRLT, ctrl);
1029
1030                 set_thread_flag(TIF_RUNLATCH);
1031         }
1032 }
1033
1034 void ppc64_runlatch_off(void)
1035 {
1036         unsigned long ctrl;
1037
1038         if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) {
1039                 HMT_medium();
1040
1041                 clear_thread_flag(TIF_RUNLATCH);
1042
1043                 ctrl = mfspr(SPRN_CTRLF);
1044                 ctrl &= ~CTRL_RUNLATCH;
1045                 mtspr(SPRN_CTRLT, ctrl);
1046         }
1047 }
1048 #endif