sparc64: Kill VERBOSE_SHOWREGS code.
[linux-2.6] / arch / sparc64 / kernel / process.c
1 /*  arch/sparc64/kernel/process.c
2  *
3  *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
4  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
5  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
6  */
7
8 /*
9  * This file handles the architecture-dependent parts of process handling..
10  */
11
12 #include <stdarg.h>
13
14 #include <linux/errno.h>
15 #include <linux/module.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/mm.h>
19 #include <linux/fs.h>
20 #include <linux/smp.h>
21 #include <linux/stddef.h>
22 #include <linux/ptrace.h>
23 #include <linux/slab.h>
24 #include <linux/user.h>
25 #include <linux/reboot.h>
26 #include <linux/delay.h>
27 #include <linux/compat.h>
28 #include <linux/tick.h>
29 #include <linux/init.h>
30 #include <linux/cpu.h>
31 #include <linux/elfcore.h>
32 #include <linux/sysrq.h>
33
34 #include <asm/oplib.h>
35 #include <asm/uaccess.h>
36 #include <asm/system.h>
37 #include <asm/page.h>
38 #include <asm/pgalloc.h>
39 #include <asm/pgtable.h>
40 #include <asm/processor.h>
41 #include <asm/pstate.h>
42 #include <asm/elf.h>
43 #include <asm/fpumacro.h>
44 #include <asm/head.h>
45 #include <asm/cpudata.h>
46 #include <asm/mmu_context.h>
47 #include <asm/unistd.h>
48 #include <asm/hypervisor.h>
49 #include <asm/sstate.h>
50 #include <asm/reboot.h>
51 #include <asm/syscalls.h>
52 #include <asm/irq_regs.h>
53 #include <asm/smp.h>
54
55 static void sparc64_yield(int cpu)
56 {
57         if (tlb_type != hypervisor)
58                 return;
59
60         clear_thread_flag(TIF_POLLING_NRFLAG);
61         smp_mb__after_clear_bit();
62
63         while (!need_resched() && !cpu_is_offline(cpu)) {
64                 unsigned long pstate;
65
66                 /* Disable interrupts. */
67                 __asm__ __volatile__(
68                         "rdpr %%pstate, %0\n\t"
69                         "andn %0, %1, %0\n\t"
70                         "wrpr %0, %%g0, %%pstate"
71                         : "=&r" (pstate)
72                         : "i" (PSTATE_IE));
73
74                 if (!need_resched() && !cpu_is_offline(cpu))
75                         sun4v_cpu_yield();
76
77                 /* Re-enable interrupts. */
78                 __asm__ __volatile__(
79                         "rdpr %%pstate, %0\n\t"
80                         "or %0, %1, %0\n\t"
81                         "wrpr %0, %%g0, %%pstate"
82                         : "=&r" (pstate)
83                         : "i" (PSTATE_IE));
84         }
85
86         set_thread_flag(TIF_POLLING_NRFLAG);
87 }
88
89 /* The idle loop on sparc64. */
90 void cpu_idle(void)
91 {
92         int cpu = smp_processor_id();
93
94         set_thread_flag(TIF_POLLING_NRFLAG);
95
96         while(1) {
97                 tick_nohz_stop_sched_tick(1);
98
99                 while (!need_resched() && !cpu_is_offline(cpu))
100                         sparc64_yield(cpu);
101
102                 tick_nohz_restart_sched_tick();
103
104                 preempt_enable_no_resched();
105
106 #ifdef CONFIG_HOTPLUG_CPU
107                 if (cpu_is_offline(cpu))
108                         cpu_play_dead();
109 #endif
110
111                 schedule();
112                 preempt_disable();
113         }
114 }
115
116 void machine_halt(void)
117 {
118         sstate_halt();
119         prom_halt();
120         panic("Halt failed!");
121 }
122
123 void machine_alt_power_off(void)
124 {
125         sstate_poweroff();
126         prom_halt_power_off();
127         panic("Power-off failed!");
128 }
129
130 void machine_restart(char * cmd)
131 {
132         char *p;
133         
134         sstate_reboot();
135         p = strchr (reboot_command, '\n');
136         if (p) *p = 0;
137         if (cmd)
138                 prom_reboot(cmd);
139         if (*reboot_command)
140                 prom_reboot(reboot_command);
141         prom_reboot("");
142         panic("Reboot failed!");
143 }
144
145 #ifdef CONFIG_COMPAT
146 static void show_regwindow32(struct pt_regs *regs)
147 {
148         struct reg_window32 __user *rw;
149         struct reg_window32 r_w;
150         mm_segment_t old_fs;
151         
152         __asm__ __volatile__ ("flushw");
153         rw = compat_ptr((unsigned)regs->u_regs[14]);
154         old_fs = get_fs();
155         set_fs (USER_DS);
156         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
157                 set_fs (old_fs);
158                 return;
159         }
160
161         set_fs (old_fs);                        
162         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
163                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
164                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
165                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
166         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
167                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
168                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
169                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
170 }
171 #else
172 #define show_regwindow32(regs)  do { } while (0)
173 #endif
174
175 static void show_regwindow(struct pt_regs *regs)
176 {
177         struct reg_window __user *rw;
178         struct reg_window *rwk;
179         struct reg_window r_w;
180         mm_segment_t old_fs;
181
182         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
183                 __asm__ __volatile__ ("flushw");
184                 rw = (struct reg_window __user *)
185                         (regs->u_regs[14] + STACK_BIAS);
186                 rwk = (struct reg_window *)
187                         (regs->u_regs[14] + STACK_BIAS);
188                 if (!(regs->tstate & TSTATE_PRIV)) {
189                         old_fs = get_fs();
190                         set_fs (USER_DS);
191                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
192                                 set_fs (old_fs);
193                                 return;
194                         }
195                         rwk = &r_w;
196                         set_fs (old_fs);                        
197                 }
198         } else {
199                 show_regwindow32(regs);
200                 return;
201         }
202         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
203                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
204         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
205                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
206         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
207                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
208         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
209                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
210         if (regs->tstate & TSTATE_PRIV)
211                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
212 }
213
214 #ifdef CONFIG_SMP
215 static DEFINE_SPINLOCK(regdump_lock);
216 #endif
217
218 void __show_regs(struct pt_regs * regs)
219 {
220 #ifdef CONFIG_SMP
221         unsigned long flags;
222
223         /* Protect against xcall ipis which might lead to livelock on the lock */
224         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
225                              "wrpr      %0, %1, %%pstate"
226                              : "=r" (flags)
227                              : "i" (PSTATE_IE));
228         spin_lock(&regdump_lock);
229 #endif
230         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
231                regs->tpc, regs->tnpc, regs->y, print_tainted());
232         printk("TPC: <%pS>\n", (void *) regs->tpc);
233         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
234                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
235                regs->u_regs[3]);
236         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
237                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
238                regs->u_regs[7]);
239         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
240                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
241                regs->u_regs[11]);
242         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
243                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
244                regs->u_regs[15]);
245         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
246         show_regwindow(regs);
247 #ifdef CONFIG_SMP
248         spin_unlock(&regdump_lock);
249         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
250                              : : "r" (flags));
251 #endif
252 }
253
254 void show_regs(struct pt_regs *regs)
255 {
256         __show_regs(regs);
257 #if 0
258 #ifdef CONFIG_SMP
259         {
260                 extern void smp_report_regs(void);
261
262                 smp_report_regs();
263         }
264 #endif
265 #endif
266 }
267
268 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
269 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
270
271 static bool kstack_valid(struct thread_info *tp, struct reg_window *rw)
272 {
273         unsigned long thread_base, fp;
274
275         thread_base = (unsigned long) tp;
276         fp = (unsigned long) rw;
277
278         if (fp < (thread_base + sizeof(struct thread_info)) ||
279             fp >= (thread_base + THREAD_SIZE))
280                 return false;
281         return true;
282 }
283
284 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
285                               int this_cpu)
286 {
287         flushw_all();
288
289         global_reg_snapshot[this_cpu].tstate = regs->tstate;
290         global_reg_snapshot[this_cpu].tpc = regs->tpc;
291         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
292         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
293
294         if (regs->tstate & TSTATE_PRIV) {
295                 struct thread_info *tp = current_thread_info();
296                 struct reg_window *rw;
297
298                 rw = (struct reg_window *)
299                         (regs->u_regs[UREG_FP] + STACK_BIAS);
300                 if (kstack_valid(tp, rw)) {
301                         global_reg_snapshot[this_cpu].i7 = rw->ins[7];
302                         rw = (struct reg_window *)
303                                 (rw->ins[6] + STACK_BIAS);
304                         if (kstack_valid(tp, rw))
305                                 global_reg_snapshot[this_cpu].rpc = rw->ins[7];
306                 }
307         } else {
308                 global_reg_snapshot[this_cpu].i7 = 0;
309                 global_reg_snapshot[this_cpu].rpc = 0;
310         }
311         global_reg_snapshot[this_cpu].thread = tp;
312 }
313
314 /* In order to avoid hangs we do not try to synchronize with the
315  * global register dump client cpus.  The last store they make is to
316  * the thread pointer, so do a short poll waiting for that to become
317  * non-NULL.
318  */
319 static void __global_reg_poll(struct global_reg_snapshot *gp)
320 {
321         int limit = 0;
322
323         while (!gp->thread && ++limit < 100) {
324                 barrier();
325                 udelay(1);
326         }
327 }
328
329 void __trigger_all_cpu_backtrace(void)
330 {
331         struct thread_info *tp = current_thread_info();
332         struct pt_regs *regs = get_irq_regs();
333         unsigned long flags;
334         int this_cpu, cpu;
335
336         if (!regs)
337                 regs = tp->kregs;
338
339         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
340
341         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
342
343         this_cpu = raw_smp_processor_id();
344
345         __global_reg_self(tp, regs, this_cpu);
346
347         smp_fetch_global_regs();
348
349         for_each_online_cpu(cpu) {
350                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
351                 struct thread_info *tp;
352
353                 __global_reg_poll(gp);
354
355                 tp = gp->thread;
356                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
357                        (cpu == this_cpu ? '*' : ' '), cpu,
358                        gp->tstate, gp->tpc, gp->tnpc,
359                        ((tp && tp->task) ? tp->task->comm : "NULL"),
360                        ((tp && tp->task) ? tp->task->pid : -1));
361
362                 if (gp->tstate & TSTATE_PRIV) {
363                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
364                                (void *) gp->tpc,
365                                (void *) gp->o7,
366                                (void *) gp->i7,
367                                (void *) gp->rpc);
368                 } else {
369                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
370                                gp->tpc, gp->o7, gp->i7, gp->rpc);
371                 }
372         }
373
374         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
375
376         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
377 }
378
379 #ifdef CONFIG_MAGIC_SYSRQ
380
381 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
382 {
383         __trigger_all_cpu_backtrace();
384 }
385
386 static struct sysrq_key_op sparc_globalreg_op = {
387         .handler        = sysrq_handle_globreg,
388         .help_msg       = "Globalregs",
389         .action_msg     = "Show Global CPU Regs",
390 };
391
392 static int __init sparc_globreg_init(void)
393 {
394         return register_sysrq_key('y', &sparc_globalreg_op);
395 }
396
397 core_initcall(sparc_globreg_init);
398
399 #endif
400
401 unsigned long thread_saved_pc(struct task_struct *tsk)
402 {
403         struct thread_info *ti = task_thread_info(tsk);
404         unsigned long ret = 0xdeadbeefUL;
405         
406         if (ti && ti->ksp) {
407                 unsigned long *sp;
408                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
409                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
410                     sp[14]) {
411                         unsigned long *fp;
412                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
413                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
414                                 ret = fp[15];
415                 }
416         }
417         return ret;
418 }
419
420 /* Free current thread data structures etc.. */
421 void exit_thread(void)
422 {
423         struct thread_info *t = current_thread_info();
424
425         if (t->utraps) {
426                 if (t->utraps[0] < 2)
427                         kfree (t->utraps);
428                 else
429                         t->utraps[0]--;
430         }
431
432         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
433                 t->user_cntd0 = t->user_cntd1 = NULL;
434                 t->pcr_reg = 0;
435                 write_pcr(0);
436         }
437 }
438
439 void flush_thread(void)
440 {
441         struct thread_info *t = current_thread_info();
442         struct mm_struct *mm;
443
444         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
445                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
446                 if (test_ti_thread_flag(t, TIF_32BIT))
447                         clear_ti_thread_flag(t, TIF_32BIT);
448                 else
449                         set_ti_thread_flag(t, TIF_32BIT);
450         }
451
452         mm = t->task->mm;
453         if (mm)
454                 tsb_context_switch(mm);
455
456         set_thread_wsaved(0);
457
458         /* Turn off performance counters if on. */
459         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
460                 t->user_cntd0 = t->user_cntd1 = NULL;
461                 t->pcr_reg = 0;
462                 write_pcr(0);
463         }
464
465         /* Clear FPU register state. */
466         t->fpsaved[0] = 0;
467         
468         if (get_thread_current_ds() != ASI_AIUS)
469                 set_fs(USER_DS);
470 }
471
472 /* It's a bit more tricky when 64-bit tasks are involved... */
473 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
474 {
475         unsigned long fp, distance, rval;
476
477         if (!(test_thread_flag(TIF_32BIT))) {
478                 csp += STACK_BIAS;
479                 psp += STACK_BIAS;
480                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
481                 fp += STACK_BIAS;
482         } else
483                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
484
485         /* Now 8-byte align the stack as this is mandatory in the
486          * Sparc ABI due to how register windows work.  This hides
487          * the restriction from thread libraries etc.  -DaveM
488          */
489         csp &= ~7UL;
490
491         distance = fp - psp;
492         rval = (csp - distance);
493         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
494                 rval = 0;
495         else if (test_thread_flag(TIF_32BIT)) {
496                 if (put_user(((u32)csp),
497                              &(((struct reg_window32 __user *)rval)->ins[6])))
498                         rval = 0;
499         } else {
500                 if (put_user(((u64)csp - STACK_BIAS),
501                              &(((struct reg_window __user *)rval)->ins[6])))
502                         rval = 0;
503                 else
504                         rval = rval - STACK_BIAS;
505         }
506
507         return rval;
508 }
509
510 /* Standard stuff. */
511 static inline void shift_window_buffer(int first_win, int last_win,
512                                        struct thread_info *t)
513 {
514         int i;
515
516         for (i = first_win; i < last_win; i++) {
517                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
518                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
519                        sizeof(struct reg_window));
520         }
521 }
522
523 void synchronize_user_stack(void)
524 {
525         struct thread_info *t = current_thread_info();
526         unsigned long window;
527
528         flush_user_windows();
529         if ((window = get_thread_wsaved()) != 0) {
530                 int winsize = sizeof(struct reg_window);
531                 int bias = 0;
532
533                 if (test_thread_flag(TIF_32BIT))
534                         winsize = sizeof(struct reg_window32);
535                 else
536                         bias = STACK_BIAS;
537
538                 window -= 1;
539                 do {
540                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
541                         struct reg_window *rwin = &t->reg_window[window];
542
543                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
544                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
545                                 set_thread_wsaved(get_thread_wsaved() - 1);
546                         }
547                 } while (window--);
548         }
549 }
550
551 static void stack_unaligned(unsigned long sp)
552 {
553         siginfo_t info;
554
555         info.si_signo = SIGBUS;
556         info.si_errno = 0;
557         info.si_code = BUS_ADRALN;
558         info.si_addr = (void __user *) sp;
559         info.si_trapno = 0;
560         force_sig_info(SIGBUS, &info, current);
561 }
562
563 void fault_in_user_windows(void)
564 {
565         struct thread_info *t = current_thread_info();
566         unsigned long window;
567         int winsize = sizeof(struct reg_window);
568         int bias = 0;
569
570         if (test_thread_flag(TIF_32BIT))
571                 winsize = sizeof(struct reg_window32);
572         else
573                 bias = STACK_BIAS;
574
575         flush_user_windows();
576         window = get_thread_wsaved();
577
578         if (likely(window != 0)) {
579                 window -= 1;
580                 do {
581                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
582                         struct reg_window *rwin = &t->reg_window[window];
583
584                         if (unlikely(sp & 0x7UL))
585                                 stack_unaligned(sp);
586
587                         if (unlikely(copy_to_user((char __user *)sp,
588                                                   rwin, winsize)))
589                                 goto barf;
590                 } while (window--);
591         }
592         set_thread_wsaved(0);
593         return;
594
595 barf:
596         set_thread_wsaved(window + 1);
597         do_exit(SIGILL);
598 }
599
600 asmlinkage long sparc_do_fork(unsigned long clone_flags,
601                               unsigned long stack_start,
602                               struct pt_regs *regs,
603                               unsigned long stack_size)
604 {
605         int __user *parent_tid_ptr, *child_tid_ptr;
606         unsigned long orig_i1 = regs->u_regs[UREG_I1];
607         long ret;
608
609 #ifdef CONFIG_COMPAT
610         if (test_thread_flag(TIF_32BIT)) {
611                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
612                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
613         } else
614 #endif
615         {
616                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
617                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
618         }
619
620         ret = do_fork(clone_flags, stack_start,
621                       regs, stack_size,
622                       parent_tid_ptr, child_tid_ptr);
623
624         /* If we get an error and potentially restart the system
625          * call, we're screwed because copy_thread() clobbered
626          * the parent's %o1.  So detect that case and restore it
627          * here.
628          */
629         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
630                 regs->u_regs[UREG_I1] = orig_i1;
631
632         return ret;
633 }
634
635 /* Copy a Sparc thread.  The fork() return value conventions
636  * under SunOS are nothing short of bletcherous:
637  * Parent -->  %o0 == childs  pid, %o1 == 0
638  * Child  -->  %o0 == parents pid, %o1 == 1
639  */
640 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
641                 unsigned long unused,
642                 struct task_struct *p, struct pt_regs *regs)
643 {
644         struct thread_info *t = task_thread_info(p);
645         struct sparc_stackf *parent_sf;
646         unsigned long child_stack_sz;
647         char *child_trap_frame;
648         int kernel_thread;
649
650         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
651         parent_sf = ((struct sparc_stackf *) regs) - 1;
652
653         /* Calculate offset to stack_frame & pt_regs */
654         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
655                           (kernel_thread ? STACKFRAME_SZ : 0));
656         child_trap_frame = (task_stack_page(p) +
657                             (THREAD_SIZE - child_stack_sz));
658         memcpy(child_trap_frame, parent_sf, child_stack_sz);
659
660         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
661                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
662                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
663         t->new_child = 1;
664         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
665         t->kregs = (struct pt_regs *) (child_trap_frame +
666                                        sizeof(struct sparc_stackf));
667         t->fpsaved[0] = 0;
668
669         if (kernel_thread) {
670                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
671                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
672
673                 /* Zero terminate the stack backtrace.  */
674                 child_sf->fp = NULL;
675                 t->kregs->u_regs[UREG_FP] =
676                   ((unsigned long) child_sf) - STACK_BIAS;
677
678                 /* Special case, if we are spawning a kernel thread from
679                  * a userspace task (usermode helper, NFS or similar), we
680                  * must disable performance counters in the child because
681                  * the address space and protection realm are changing.
682                  */
683                 if (t->flags & _TIF_PERFCTR) {
684                         t->user_cntd0 = t->user_cntd1 = NULL;
685                         t->pcr_reg = 0;
686                         t->flags &= ~_TIF_PERFCTR;
687                 }
688                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
689                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
690                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
691         } else {
692                 if (t->flags & _TIF_32BIT) {
693                         sp &= 0x00000000ffffffffUL;
694                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
695                 }
696                 t->kregs->u_regs[UREG_FP] = sp;
697                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
698                 if (sp != regs->u_regs[UREG_FP]) {
699                         unsigned long csp;
700
701                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
702                         if (!csp)
703                                 return -EFAULT;
704                         t->kregs->u_regs[UREG_FP] = csp;
705                 }
706                 if (t->utraps)
707                         t->utraps[0]++;
708         }
709
710         /* Set the return value for the child. */
711         t->kregs->u_regs[UREG_I0] = current->pid;
712         t->kregs->u_regs[UREG_I1] = 1;
713
714         /* Set the second return value for the parent. */
715         regs->u_regs[UREG_I1] = 0;
716
717         if (clone_flags & CLONE_SETTLS)
718                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
719
720         return 0;
721 }
722
723 /*
724  * This is the mechanism for creating a new kernel thread.
725  *
726  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
727  * who haven't done an "execve()") should use this: it will work within
728  * a system call from a "real" process, but the process memory space will
729  * not be freed until both the parent and the child have exited.
730  */
731 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
732 {
733         long retval;
734
735         /* If the parent runs before fn(arg) is called by the child,
736          * the input registers of this function can be clobbered.
737          * So we stash 'fn' and 'arg' into global registers which
738          * will not be modified by the parent.
739          */
740         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
741                              "mov %5, %%g3\n\t"    /* Save ARG into global */
742                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
743                              "mov %2, %%o0\n\t"    /* Clone flags. */
744                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
745                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
746                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
747                              " mov %%o0, %0\n\t"
748                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
749                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
750                              "mov %3, %%g1\n\t"
751                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
752                              /* Notreached by child. */
753                              "1:" :
754                              "=r" (retval) :
755                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
756                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
757                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
758         return retval;
759 }
760
761 typedef struct {
762         union {
763                 unsigned int    pr_regs[32];
764                 unsigned long   pr_dregs[16];
765         } pr_fr;
766         unsigned int __unused;
767         unsigned int    pr_fsr;
768         unsigned char   pr_qcnt;
769         unsigned char   pr_q_entrysize;
770         unsigned char   pr_en;
771         unsigned int    pr_q[64];
772 } elf_fpregset_t32;
773
774 /*
775  * fill in the fpu structure for a core dump.
776  */
777 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
778 {
779         unsigned long *kfpregs = current_thread_info()->fpregs;
780         unsigned long fprs = current_thread_info()->fpsaved[0];
781
782         if (test_thread_flag(TIF_32BIT)) {
783                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
784
785                 if (fprs & FPRS_DL)
786                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
787                                sizeof(unsigned int) * 32);
788                 else
789                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
790                                sizeof(unsigned int) * 32);
791                 fpregs32->pr_qcnt = 0;
792                 fpregs32->pr_q_entrysize = 8;
793                 memset(&fpregs32->pr_q[0], 0,
794                        (sizeof(unsigned int) * 64));
795                 if (fprs & FPRS_FEF) {
796                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
797                         fpregs32->pr_en = 1;
798                 } else {
799                         fpregs32->pr_fsr = 0;
800                         fpregs32->pr_en = 0;
801                 }
802         } else {
803                 if(fprs & FPRS_DL)
804                         memcpy(&fpregs->pr_regs[0], kfpregs,
805                                sizeof(unsigned int) * 32);
806                 else
807                         memset(&fpregs->pr_regs[0], 0,
808                                sizeof(unsigned int) * 32);
809                 if(fprs & FPRS_DU)
810                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
811                                sizeof(unsigned int) * 32);
812                 else
813                         memset(&fpregs->pr_regs[16], 0,
814                                sizeof(unsigned int) * 32);
815                 if(fprs & FPRS_FEF) {
816                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
817                         fpregs->pr_gsr = current_thread_info()->gsr[0];
818                 } else {
819                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
820                 }
821                 fpregs->pr_fprs = fprs;
822         }
823         return 1;
824 }
825
826 /*
827  * sparc_execve() executes a new program after the asm stub has set
828  * things up for us.  This should basically do what I want it to.
829  */
830 asmlinkage int sparc_execve(struct pt_regs *regs)
831 {
832         int error, base = 0;
833         char *filename;
834
835         /* User register window flush is done by entry.S */
836
837         /* Check for indirect call. */
838         if (regs->u_regs[UREG_G1] == 0)
839                 base = 1;
840
841         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
842         error = PTR_ERR(filename);
843         if (IS_ERR(filename))
844                 goto out;
845         error = do_execve(filename,
846                           (char __user * __user *)
847                           regs->u_regs[base + UREG_I1],
848                           (char __user * __user *)
849                           regs->u_regs[base + UREG_I2], regs);
850         putname(filename);
851         if (!error) {
852                 fprs_write(0);
853                 current_thread_info()->xfsr[0] = 0;
854                 current_thread_info()->fpsaved[0] = 0;
855                 regs->tstate &= ~TSTATE_PEF;
856         }
857 out:
858         return error;
859 }
860
861 unsigned long get_wchan(struct task_struct *task)
862 {
863         unsigned long pc, fp, bias = 0;
864         unsigned long thread_info_base;
865         struct reg_window *rw;
866         unsigned long ret = 0;
867         int count = 0; 
868
869         if (!task || task == current ||
870             task->state == TASK_RUNNING)
871                 goto out;
872
873         thread_info_base = (unsigned long) task_stack_page(task);
874         bias = STACK_BIAS;
875         fp = task_thread_info(task)->ksp + bias;
876
877         do {
878                 /* Bogus frame pointer? */
879                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
880                     fp >= (thread_info_base + THREAD_SIZE))
881                         break;
882                 rw = (struct reg_window *) fp;
883                 pc = rw->ins[7];
884                 if (!in_sched_functions(pc)) {
885                         ret = pc;
886                         goto out;
887                 }
888                 fp = rw->ins[6] + bias;
889         } while (++count < 16);
890
891 out:
892         return ret;
893 }