sparc64: Hook up trigger_all_cpu_backtrace().
[linux-2.6.git] / 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 /* #define VERBOSE_SHOWREGS */
56
57 static void sparc64_yield(int cpu)
58 {
59         if (tlb_type != hypervisor)
60                 return;
61
62         clear_thread_flag(TIF_POLLING_NRFLAG);
63         smp_mb__after_clear_bit();
64
65         while (!need_resched() && !cpu_is_offline(cpu)) {
66                 unsigned long pstate;
67
68                 /* Disable interrupts. */
69                 __asm__ __volatile__(
70                         "rdpr %%pstate, %0\n\t"
71                         "andn %0, %1, %0\n\t"
72                         "wrpr %0, %%g0, %%pstate"
73                         : "=&r" (pstate)
74                         : "i" (PSTATE_IE));
75
76                 if (!need_resched() && !cpu_is_offline(cpu))
77                         sun4v_cpu_yield();
78
79                 /* Re-enable interrupts. */
80                 __asm__ __volatile__(
81                         "rdpr %%pstate, %0\n\t"
82                         "or %0, %1, %0\n\t"
83                         "wrpr %0, %%g0, %%pstate"
84                         : "=&r" (pstate)
85                         : "i" (PSTATE_IE));
86         }
87
88         set_thread_flag(TIF_POLLING_NRFLAG);
89 }
90
91 /* The idle loop on sparc64. */
92 void cpu_idle(void)
93 {
94         int cpu = smp_processor_id();
95
96         set_thread_flag(TIF_POLLING_NRFLAG);
97
98         while(1) {
99                 tick_nohz_stop_sched_tick(1);
100
101                 while (!need_resched() && !cpu_is_offline(cpu))
102                         sparc64_yield(cpu);
103
104                 tick_nohz_restart_sched_tick();
105
106                 preempt_enable_no_resched();
107
108 #ifdef CONFIG_HOTPLUG_CPU
109                 if (cpu_is_offline(cpu))
110                         cpu_play_dead();
111 #endif
112
113                 schedule();
114                 preempt_disable();
115         }
116 }
117
118 void machine_halt(void)
119 {
120         sstate_halt();
121         prom_halt();
122         panic("Halt failed!");
123 }
124
125 void machine_alt_power_off(void)
126 {
127         sstate_poweroff();
128         prom_halt_power_off();
129         panic("Power-off failed!");
130 }
131
132 void machine_restart(char * cmd)
133 {
134         char *p;
135         
136         sstate_reboot();
137         p = strchr (reboot_command, '\n');
138         if (p) *p = 0;
139         if (cmd)
140                 prom_reboot(cmd);
141         if (*reboot_command)
142                 prom_reboot(reboot_command);
143         prom_reboot("");
144         panic("Reboot failed!");
145 }
146
147 #ifdef CONFIG_COMPAT
148 static void show_regwindow32(struct pt_regs *regs)
149 {
150         struct reg_window32 __user *rw;
151         struct reg_window32 r_w;
152         mm_segment_t old_fs;
153         
154         __asm__ __volatile__ ("flushw");
155         rw = compat_ptr((unsigned)regs->u_regs[14]);
156         old_fs = get_fs();
157         set_fs (USER_DS);
158         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
159                 set_fs (old_fs);
160                 return;
161         }
162
163         set_fs (old_fs);                        
164         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
165                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
166                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
167                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
168         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
169                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
170                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
171                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
172 }
173 #else
174 #define show_regwindow32(regs)  do { } while (0)
175 #endif
176
177 static void show_regwindow(struct pt_regs *regs)
178 {
179         struct reg_window __user *rw;
180         struct reg_window *rwk;
181         struct reg_window r_w;
182         mm_segment_t old_fs;
183
184         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
185                 __asm__ __volatile__ ("flushw");
186                 rw = (struct reg_window __user *)
187                         (regs->u_regs[14] + STACK_BIAS);
188                 rwk = (struct reg_window *)
189                         (regs->u_regs[14] + STACK_BIAS);
190                 if (!(regs->tstate & TSTATE_PRIV)) {
191                         old_fs = get_fs();
192                         set_fs (USER_DS);
193                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
194                                 set_fs (old_fs);
195                                 return;
196                         }
197                         rwk = &r_w;
198                         set_fs (old_fs);                        
199                 }
200         } else {
201                 show_regwindow32(regs);
202                 return;
203         }
204         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
205                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
206         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
207                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
208         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
209                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
210         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
211                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
212         if (regs->tstate & TSTATE_PRIV)
213                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
214 }
215
216 #ifdef CONFIG_SMP
217 static DEFINE_SPINLOCK(regdump_lock);
218 #endif
219
220 void __show_regs(struct pt_regs * regs)
221 {
222 #ifdef CONFIG_SMP
223         unsigned long flags;
224
225         /* Protect against xcall ipis which might lead to livelock on the lock */
226         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
227                              "wrpr      %0, %1, %%pstate"
228                              : "=r" (flags)
229                              : "i" (PSTATE_IE));
230         spin_lock(&regdump_lock);
231 #endif
232         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
233                regs->tpc, regs->tnpc, regs->y, print_tainted());
234         printk("TPC: <%pS>\n", (void *) regs->tpc);
235         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
236                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
237                regs->u_regs[3]);
238         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
239                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
240                regs->u_regs[7]);
241         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
242                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
243                regs->u_regs[11]);
244         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
245                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
246                regs->u_regs[15]);
247         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
248         show_regwindow(regs);
249 #ifdef CONFIG_SMP
250         spin_unlock(&regdump_lock);
251         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
252                              : : "r" (flags));
253 #endif
254 }
255
256 #ifdef VERBOSE_SHOWREGS
257 static void idump_from_user (unsigned int *pc)
258 {
259         int i;
260         int code;
261         
262         if((((unsigned long) pc) & 3))
263                 return;
264         
265         pc -= 3;
266         for(i = -3; i < 6; i++) {
267                 get_user(code, pc);
268                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
269                 pc++;
270         }
271         printk("\n");
272 }
273 #endif
274
275 void show_regs(struct pt_regs *regs)
276 {
277 #ifdef VERBOSE_SHOWREGS
278         extern long etrap, etraptl1;
279 #endif
280         __show_regs(regs);
281 #if 0
282 #ifdef CONFIG_SMP
283         {
284                 extern void smp_report_regs(void);
285
286                 smp_report_regs();
287         }
288 #endif
289 #endif
290
291 #ifdef VERBOSE_SHOWREGS 
292         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
293             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
294             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
295                 printk ("*********parent**********\n");
296                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
297                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
298                 printk ("*********endpar**********\n");
299         }
300 #endif
301 }
302
303 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
304 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
305
306 static bool kstack_valid(struct thread_info *tp, struct reg_window *rw)
307 {
308         unsigned long thread_base, fp;
309
310         thread_base = (unsigned long) tp;
311         fp = (unsigned long) rw;
312
313         if (fp < (thread_base + sizeof(struct thread_info)) ||
314             fp >= (thread_base + THREAD_SIZE))
315                 return false;
316         return true;
317 }
318
319 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
320                               int this_cpu)
321 {
322         flushw_all();
323
324         global_reg_snapshot[this_cpu].tstate = regs->tstate;
325         global_reg_snapshot[this_cpu].tpc = regs->tpc;
326         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
327         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
328
329         if (regs->tstate & TSTATE_PRIV) {
330                 struct thread_info *tp = current_thread_info();
331                 struct reg_window *rw;
332
333                 rw = (struct reg_window *)
334                         (regs->u_regs[UREG_FP] + STACK_BIAS);
335                 if (kstack_valid(tp, rw)) {
336                         global_reg_snapshot[this_cpu].i7 = rw->ins[7];
337                         rw = (struct reg_window *)
338                                 (rw->ins[6] + STACK_BIAS);
339                         if (kstack_valid(tp, rw))
340                                 global_reg_snapshot[this_cpu].rpc = rw->ins[7];
341                 }
342         } else {
343                 global_reg_snapshot[this_cpu].i7 = 0;
344                 global_reg_snapshot[this_cpu].rpc = 0;
345         }
346         global_reg_snapshot[this_cpu].thread = tp;
347 }
348
349 /* In order to avoid hangs we do not try to synchronize with the
350  * global register dump client cpus.  The last store they make is to
351  * the thread pointer, so do a short poll waiting for that to become
352  * non-NULL.
353  */
354 static void __global_reg_poll(struct global_reg_snapshot *gp)
355 {
356         int limit = 0;
357
358         while (!gp->thread && ++limit < 100) {
359                 barrier();
360                 udelay(1);
361         }
362 }
363
364 void __trigger_all_cpu_backtrace(void)
365 {
366         struct thread_info *tp = current_thread_info();
367         struct pt_regs *regs = get_irq_regs();
368         unsigned long flags;
369         int this_cpu, cpu;
370
371         if (!regs)
372                 regs = tp->kregs;
373
374         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
375
376         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
377
378         this_cpu = raw_smp_processor_id();
379
380         __global_reg_self(tp, regs, this_cpu);
381
382         smp_fetch_global_regs();
383
384         for_each_online_cpu(cpu) {
385                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
386                 struct thread_info *tp;
387
388                 __global_reg_poll(gp);
389
390                 tp = gp->thread;
391                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
392                        (cpu == this_cpu ? '*' : ' '), cpu,
393                        gp->tstate, gp->tpc, gp->tnpc,
394                        ((tp && tp->task) ? tp->task->comm : "NULL"),
395                        ((tp && tp->task) ? tp->task->pid : -1));
396
397                 if (gp->tstate & TSTATE_PRIV) {
398                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
399                                (void *) gp->tpc,
400                                (void *) gp->o7,
401                                (void *) gp->i7,
402                                (void *) gp->rpc);
403                 } else {
404                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
405                                gp->tpc, gp->o7, gp->i7, gp->rpc);
406                 }
407         }
408
409         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
410
411         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
412 }
413
414 #ifdef CONFIG_MAGIC_SYSRQ
415
416 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
417 {
418         __trigger_all_cpu_backtrace();
419 }
420
421 static struct sysrq_key_op sparc_globalreg_op = {
422         .handler        = sysrq_handle_globreg,
423         .help_msg       = "Globalregs",
424         .action_msg     = "Show Global CPU Regs",
425 };
426
427 static int __init sparc_globreg_init(void)
428 {
429         return register_sysrq_key('y', &sparc_globalreg_op);
430 }
431
432 core_initcall(sparc_globreg_init);
433
434 #endif
435
436 unsigned long thread_saved_pc(struct task_struct *tsk)
437 {
438         struct thread_info *ti = task_thread_info(tsk);
439         unsigned long ret = 0xdeadbeefUL;
440         
441         if (ti && ti->ksp) {
442                 unsigned long *sp;
443                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
444                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
445                     sp[14]) {
446                         unsigned long *fp;
447                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
448                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
449                                 ret = fp[15];
450                 }
451         }
452         return ret;
453 }
454
455 /* Free current thread data structures etc.. */
456 void exit_thread(void)
457 {
458         struct thread_info *t = current_thread_info();
459
460         if (t->utraps) {
461                 if (t->utraps[0] < 2)
462                         kfree (t->utraps);
463                 else
464                         t->utraps[0]--;
465         }
466
467         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
468                 t->user_cntd0 = t->user_cntd1 = NULL;
469                 t->pcr_reg = 0;
470                 write_pcr(0);
471         }
472 }
473
474 void flush_thread(void)
475 {
476         struct thread_info *t = current_thread_info();
477         struct mm_struct *mm;
478
479         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
480                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
481                 if (test_ti_thread_flag(t, TIF_32BIT))
482                         clear_ti_thread_flag(t, TIF_32BIT);
483                 else
484                         set_ti_thread_flag(t, TIF_32BIT);
485         }
486
487         mm = t->task->mm;
488         if (mm)
489                 tsb_context_switch(mm);
490
491         set_thread_wsaved(0);
492
493         /* Turn off performance counters if on. */
494         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
495                 t->user_cntd0 = t->user_cntd1 = NULL;
496                 t->pcr_reg = 0;
497                 write_pcr(0);
498         }
499
500         /* Clear FPU register state. */
501         t->fpsaved[0] = 0;
502         
503         if (get_thread_current_ds() != ASI_AIUS)
504                 set_fs(USER_DS);
505 }
506
507 /* It's a bit more tricky when 64-bit tasks are involved... */
508 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
509 {
510         unsigned long fp, distance, rval;
511
512         if (!(test_thread_flag(TIF_32BIT))) {
513                 csp += STACK_BIAS;
514                 psp += STACK_BIAS;
515                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
516                 fp += STACK_BIAS;
517         } else
518                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
519
520         /* Now 8-byte align the stack as this is mandatory in the
521          * Sparc ABI due to how register windows work.  This hides
522          * the restriction from thread libraries etc.  -DaveM
523          */
524         csp &= ~7UL;
525
526         distance = fp - psp;
527         rval = (csp - distance);
528         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
529                 rval = 0;
530         else if (test_thread_flag(TIF_32BIT)) {
531                 if (put_user(((u32)csp),
532                              &(((struct reg_window32 __user *)rval)->ins[6])))
533                         rval = 0;
534         } else {
535                 if (put_user(((u64)csp - STACK_BIAS),
536                              &(((struct reg_window __user *)rval)->ins[6])))
537                         rval = 0;
538                 else
539                         rval = rval - STACK_BIAS;
540         }
541
542         return rval;
543 }
544
545 /* Standard stuff. */
546 static inline void shift_window_buffer(int first_win, int last_win,
547                                        struct thread_info *t)
548 {
549         int i;
550
551         for (i = first_win; i < last_win; i++) {
552                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
553                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
554                        sizeof(struct reg_window));
555         }
556 }
557
558 void synchronize_user_stack(void)
559 {
560         struct thread_info *t = current_thread_info();
561         unsigned long window;
562
563         flush_user_windows();
564         if ((window = get_thread_wsaved()) != 0) {
565                 int winsize = sizeof(struct reg_window);
566                 int bias = 0;
567
568                 if (test_thread_flag(TIF_32BIT))
569                         winsize = sizeof(struct reg_window32);
570                 else
571                         bias = STACK_BIAS;
572
573                 window -= 1;
574                 do {
575                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
576                         struct reg_window *rwin = &t->reg_window[window];
577
578                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
579                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
580                                 set_thread_wsaved(get_thread_wsaved() - 1);
581                         }
582                 } while (window--);
583         }
584 }
585
586 static void stack_unaligned(unsigned long sp)
587 {
588         siginfo_t info;
589
590         info.si_signo = SIGBUS;
591         info.si_errno = 0;
592         info.si_code = BUS_ADRALN;
593         info.si_addr = (void __user *) sp;
594         info.si_trapno = 0;
595         force_sig_info(SIGBUS, &info, current);
596 }
597
598 void fault_in_user_windows(void)
599 {
600         struct thread_info *t = current_thread_info();
601         unsigned long window;
602         int winsize = sizeof(struct reg_window);
603         int bias = 0;
604
605         if (test_thread_flag(TIF_32BIT))
606                 winsize = sizeof(struct reg_window32);
607         else
608                 bias = STACK_BIAS;
609
610         flush_user_windows();
611         window = get_thread_wsaved();
612
613         if (likely(window != 0)) {
614                 window -= 1;
615                 do {
616                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
617                         struct reg_window *rwin = &t->reg_window[window];
618
619                         if (unlikely(sp & 0x7UL))
620                                 stack_unaligned(sp);
621
622                         if (unlikely(copy_to_user((char __user *)sp,
623                                                   rwin, winsize)))
624                                 goto barf;
625                 } while (window--);
626         }
627         set_thread_wsaved(0);
628         return;
629
630 barf:
631         set_thread_wsaved(window + 1);
632         do_exit(SIGILL);
633 }
634
635 asmlinkage long sparc_do_fork(unsigned long clone_flags,
636                               unsigned long stack_start,
637                               struct pt_regs *regs,
638                               unsigned long stack_size)
639 {
640         int __user *parent_tid_ptr, *child_tid_ptr;
641         unsigned long orig_i1 = regs->u_regs[UREG_I1];
642         long ret;
643
644 #ifdef CONFIG_COMPAT
645         if (test_thread_flag(TIF_32BIT)) {
646                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
647                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
648         } else
649 #endif
650         {
651                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
652                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
653         }
654
655         ret = do_fork(clone_flags, stack_start,
656                       regs, stack_size,
657                       parent_tid_ptr, child_tid_ptr);
658
659         /* If we get an error and potentially restart the system
660          * call, we're screwed because copy_thread() clobbered
661          * the parent's %o1.  So detect that case and restore it
662          * here.
663          */
664         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
665                 regs->u_regs[UREG_I1] = orig_i1;
666
667         return ret;
668 }
669
670 /* Copy a Sparc thread.  The fork() return value conventions
671  * under SunOS are nothing short of bletcherous:
672  * Parent -->  %o0 == childs  pid, %o1 == 0
673  * Child  -->  %o0 == parents pid, %o1 == 1
674  */
675 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
676                 unsigned long unused,
677                 struct task_struct *p, struct pt_regs *regs)
678 {
679         struct thread_info *t = task_thread_info(p);
680         struct sparc_stackf *parent_sf;
681         unsigned long child_stack_sz;
682         char *child_trap_frame;
683         int kernel_thread;
684
685         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
686         parent_sf = ((struct sparc_stackf *) regs) - 1;
687
688         /* Calculate offset to stack_frame & pt_regs */
689         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
690                           (kernel_thread ? STACKFRAME_SZ : 0));
691         child_trap_frame = (task_stack_page(p) +
692                             (THREAD_SIZE - child_stack_sz));
693         memcpy(child_trap_frame, parent_sf, child_stack_sz);
694
695         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
696                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
697                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
698         t->new_child = 1;
699         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
700         t->kregs = (struct pt_regs *) (child_trap_frame +
701                                        sizeof(struct sparc_stackf));
702         t->fpsaved[0] = 0;
703
704         if (kernel_thread) {
705                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
706                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
707
708                 /* Zero terminate the stack backtrace.  */
709                 child_sf->fp = NULL;
710                 t->kregs->u_regs[UREG_FP] =
711                   ((unsigned long) child_sf) - STACK_BIAS;
712
713                 /* Special case, if we are spawning a kernel thread from
714                  * a userspace task (usermode helper, NFS or similar), we
715                  * must disable performance counters in the child because
716                  * the address space and protection realm are changing.
717                  */
718                 if (t->flags & _TIF_PERFCTR) {
719                         t->user_cntd0 = t->user_cntd1 = NULL;
720                         t->pcr_reg = 0;
721                         t->flags &= ~_TIF_PERFCTR;
722                 }
723                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
724                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
725                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
726         } else {
727                 if (t->flags & _TIF_32BIT) {
728                         sp &= 0x00000000ffffffffUL;
729                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
730                 }
731                 t->kregs->u_regs[UREG_FP] = sp;
732                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
733                 if (sp != regs->u_regs[UREG_FP]) {
734                         unsigned long csp;
735
736                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
737                         if (!csp)
738                                 return -EFAULT;
739                         t->kregs->u_regs[UREG_FP] = csp;
740                 }
741                 if (t->utraps)
742                         t->utraps[0]++;
743         }
744
745         /* Set the return value for the child. */
746         t->kregs->u_regs[UREG_I0] = current->pid;
747         t->kregs->u_regs[UREG_I1] = 1;
748
749         /* Set the second return value for the parent. */
750         regs->u_regs[UREG_I1] = 0;
751
752         if (clone_flags & CLONE_SETTLS)
753                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
754
755         return 0;
756 }
757
758 /*
759  * This is the mechanism for creating a new kernel thread.
760  *
761  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
762  * who haven't done an "execve()") should use this: it will work within
763  * a system call from a "real" process, but the process memory space will
764  * not be freed until both the parent and the child have exited.
765  */
766 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
767 {
768         long retval;
769
770         /* If the parent runs before fn(arg) is called by the child,
771          * the input registers of this function can be clobbered.
772          * So we stash 'fn' and 'arg' into global registers which
773          * will not be modified by the parent.
774          */
775         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
776                              "mov %5, %%g3\n\t"    /* Save ARG into global */
777                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
778                              "mov %2, %%o0\n\t"    /* Clone flags. */
779                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
780                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
781                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
782                              " mov %%o0, %0\n\t"
783                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
784                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
785                              "mov %3, %%g1\n\t"
786                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
787                              /* Notreached by child. */
788                              "1:" :
789                              "=r" (retval) :
790                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
791                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
792                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
793         return retval;
794 }
795
796 typedef struct {
797         union {
798                 unsigned int    pr_regs[32];
799                 unsigned long   pr_dregs[16];
800         } pr_fr;
801         unsigned int __unused;
802         unsigned int    pr_fsr;
803         unsigned char   pr_qcnt;
804         unsigned char   pr_q_entrysize;
805         unsigned char   pr_en;
806         unsigned int    pr_q[64];
807 } elf_fpregset_t32;
808
809 /*
810  * fill in the fpu structure for a core dump.
811  */
812 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
813 {
814         unsigned long *kfpregs = current_thread_info()->fpregs;
815         unsigned long fprs = current_thread_info()->fpsaved[0];
816
817         if (test_thread_flag(TIF_32BIT)) {
818                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
819
820                 if (fprs & FPRS_DL)
821                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
822                                sizeof(unsigned int) * 32);
823                 else
824                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
825                                sizeof(unsigned int) * 32);
826                 fpregs32->pr_qcnt = 0;
827                 fpregs32->pr_q_entrysize = 8;
828                 memset(&fpregs32->pr_q[0], 0,
829                        (sizeof(unsigned int) * 64));
830                 if (fprs & FPRS_FEF) {
831                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
832                         fpregs32->pr_en = 1;
833                 } else {
834                         fpregs32->pr_fsr = 0;
835                         fpregs32->pr_en = 0;
836                 }
837         } else {
838                 if(fprs & FPRS_DL)
839                         memcpy(&fpregs->pr_regs[0], kfpregs,
840                                sizeof(unsigned int) * 32);
841                 else
842                         memset(&fpregs->pr_regs[0], 0,
843                                sizeof(unsigned int) * 32);
844                 if(fprs & FPRS_DU)
845                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
846                                sizeof(unsigned int) * 32);
847                 else
848                         memset(&fpregs->pr_regs[16], 0,
849                                sizeof(unsigned int) * 32);
850                 if(fprs & FPRS_FEF) {
851                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
852                         fpregs->pr_gsr = current_thread_info()->gsr[0];
853                 } else {
854                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
855                 }
856                 fpregs->pr_fprs = fprs;
857         }
858         return 1;
859 }
860
861 /*
862  * sparc_execve() executes a new program after the asm stub has set
863  * things up for us.  This should basically do what I want it to.
864  */
865 asmlinkage int sparc_execve(struct pt_regs *regs)
866 {
867         int error, base = 0;
868         char *filename;
869
870         /* User register window flush is done by entry.S */
871
872         /* Check for indirect call. */
873         if (regs->u_regs[UREG_G1] == 0)
874                 base = 1;
875
876         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
877         error = PTR_ERR(filename);
878         if (IS_ERR(filename))
879                 goto out;
880         error = do_execve(filename,
881                           (char __user * __user *)
882                           regs->u_regs[base + UREG_I1],
883                           (char __user * __user *)
884                           regs->u_regs[base + UREG_I2], regs);
885         putname(filename);
886         if (!error) {
887                 fprs_write(0);
888                 current_thread_info()->xfsr[0] = 0;
889                 current_thread_info()->fpsaved[0] = 0;
890                 regs->tstate &= ~TSTATE_PEF;
891         }
892 out:
893         return error;
894 }
895
896 unsigned long get_wchan(struct task_struct *task)
897 {
898         unsigned long pc, fp, bias = 0;
899         unsigned long thread_info_base;
900         struct reg_window *rw;
901         unsigned long ret = 0;
902         int count = 0; 
903
904         if (!task || task == current ||
905             task->state == TASK_RUNNING)
906                 goto out;
907
908         thread_info_base = (unsigned long) task_stack_page(task);
909         bias = STACK_BIAS;
910         fp = task_thread_info(task)->ksp + bias;
911
912         do {
913                 /* Bogus frame pointer? */
914                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
915                     fp >= (thread_info_base + THREAD_SIZE))
916                         break;
917                 rw = (struct reg_window *) fp;
918                 pc = rw->ins[7];
919                 if (!in_sched_functions(pc)) {
920                         ret = pc;
921                         goto out;
922                 }
923                 fp = rw->ins[6] + bias;
924         } while (++count < 16);
925
926 out:
927         return ret;
928 }