Merge http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm into...
[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 void show_regs(struct pt_regs *regs)
215 {
216         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
217                regs->tpc, regs->tnpc, regs->y, print_tainted());
218         printk("TPC: <%pS>\n", (void *) regs->tpc);
219         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
220                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
221                regs->u_regs[3]);
222         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
223                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
224                regs->u_regs[7]);
225         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
226                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
227                regs->u_regs[11]);
228         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
229                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
230                regs->u_regs[15]);
231         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
232         show_regwindow(regs);
233 }
234
235 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
236 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
237
238 static bool kstack_valid(struct thread_info *tp, struct reg_window *rw)
239 {
240         unsigned long thread_base, fp;
241
242         thread_base = (unsigned long) tp;
243         fp = (unsigned long) rw;
244
245         if (fp < (thread_base + sizeof(struct thread_info)) ||
246             fp >= (thread_base + THREAD_SIZE))
247                 return false;
248         return true;
249 }
250
251 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
252                               int this_cpu)
253 {
254         flushw_all();
255
256         global_reg_snapshot[this_cpu].tstate = regs->tstate;
257         global_reg_snapshot[this_cpu].tpc = regs->tpc;
258         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
259         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
260
261         if (regs->tstate & TSTATE_PRIV) {
262                 struct thread_info *tp = current_thread_info();
263                 struct reg_window *rw;
264
265                 rw = (struct reg_window *)
266                         (regs->u_regs[UREG_FP] + STACK_BIAS);
267                 if (kstack_valid(tp, rw)) {
268                         global_reg_snapshot[this_cpu].i7 = rw->ins[7];
269                         rw = (struct reg_window *)
270                                 (rw->ins[6] + STACK_BIAS);
271                         if (kstack_valid(tp, rw))
272                                 global_reg_snapshot[this_cpu].rpc = rw->ins[7];
273                 }
274         } else {
275                 global_reg_snapshot[this_cpu].i7 = 0;
276                 global_reg_snapshot[this_cpu].rpc = 0;
277         }
278         global_reg_snapshot[this_cpu].thread = tp;
279 }
280
281 /* In order to avoid hangs we do not try to synchronize with the
282  * global register dump client cpus.  The last store they make is to
283  * the thread pointer, so do a short poll waiting for that to become
284  * non-NULL.
285  */
286 static void __global_reg_poll(struct global_reg_snapshot *gp)
287 {
288         int limit = 0;
289
290         while (!gp->thread && ++limit < 100) {
291                 barrier();
292                 udelay(1);
293         }
294 }
295
296 void __trigger_all_cpu_backtrace(void)
297 {
298         struct thread_info *tp = current_thread_info();
299         struct pt_regs *regs = get_irq_regs();
300         unsigned long flags;
301         int this_cpu, cpu;
302
303         if (!regs)
304                 regs = tp->kregs;
305
306         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
307
308         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
309
310         this_cpu = raw_smp_processor_id();
311
312         __global_reg_self(tp, regs, this_cpu);
313
314         smp_fetch_global_regs();
315
316         for_each_online_cpu(cpu) {
317                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
318                 struct thread_info *tp;
319
320                 __global_reg_poll(gp);
321
322                 tp = gp->thread;
323                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
324                        (cpu == this_cpu ? '*' : ' '), cpu,
325                        gp->tstate, gp->tpc, gp->tnpc,
326                        ((tp && tp->task) ? tp->task->comm : "NULL"),
327                        ((tp && tp->task) ? tp->task->pid : -1));
328
329                 if (gp->tstate & TSTATE_PRIV) {
330                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
331                                (void *) gp->tpc,
332                                (void *) gp->o7,
333                                (void *) gp->i7,
334                                (void *) gp->rpc);
335                 } else {
336                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
337                                gp->tpc, gp->o7, gp->i7, gp->rpc);
338                 }
339         }
340
341         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
342
343         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
344 }
345
346 #ifdef CONFIG_MAGIC_SYSRQ
347
348 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
349 {
350         __trigger_all_cpu_backtrace();
351 }
352
353 static struct sysrq_key_op sparc_globalreg_op = {
354         .handler        = sysrq_handle_globreg,
355         .help_msg       = "Globalregs",
356         .action_msg     = "Show Global CPU Regs",
357 };
358
359 static int __init sparc_globreg_init(void)
360 {
361         return register_sysrq_key('y', &sparc_globalreg_op);
362 }
363
364 core_initcall(sparc_globreg_init);
365
366 #endif
367
368 unsigned long thread_saved_pc(struct task_struct *tsk)
369 {
370         struct thread_info *ti = task_thread_info(tsk);
371         unsigned long ret = 0xdeadbeefUL;
372         
373         if (ti && ti->ksp) {
374                 unsigned long *sp;
375                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
376                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
377                     sp[14]) {
378                         unsigned long *fp;
379                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
380                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
381                                 ret = fp[15];
382                 }
383         }
384         return ret;
385 }
386
387 /* Free current thread data structures etc.. */
388 void exit_thread(void)
389 {
390         struct thread_info *t = current_thread_info();
391
392         if (t->utraps) {
393                 if (t->utraps[0] < 2)
394                         kfree (t->utraps);
395                 else
396                         t->utraps[0]--;
397         }
398
399         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
400                 t->user_cntd0 = t->user_cntd1 = NULL;
401                 t->pcr_reg = 0;
402                 write_pcr(0);
403         }
404 }
405
406 void flush_thread(void)
407 {
408         struct thread_info *t = current_thread_info();
409         struct mm_struct *mm;
410
411         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
412                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
413                 if (test_ti_thread_flag(t, TIF_32BIT))
414                         clear_ti_thread_flag(t, TIF_32BIT);
415                 else
416                         set_ti_thread_flag(t, TIF_32BIT);
417         }
418
419         mm = t->task->mm;
420         if (mm)
421                 tsb_context_switch(mm);
422
423         set_thread_wsaved(0);
424
425         /* Turn off performance counters if on. */
426         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
427                 t->user_cntd0 = t->user_cntd1 = NULL;
428                 t->pcr_reg = 0;
429                 write_pcr(0);
430         }
431
432         /* Clear FPU register state. */
433         t->fpsaved[0] = 0;
434         
435         if (get_thread_current_ds() != ASI_AIUS)
436                 set_fs(USER_DS);
437 }
438
439 /* It's a bit more tricky when 64-bit tasks are involved... */
440 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
441 {
442         unsigned long fp, distance, rval;
443
444         if (!(test_thread_flag(TIF_32BIT))) {
445                 csp += STACK_BIAS;
446                 psp += STACK_BIAS;
447                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
448                 fp += STACK_BIAS;
449         } else
450                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
451
452         /* Now 8-byte align the stack as this is mandatory in the
453          * Sparc ABI due to how register windows work.  This hides
454          * the restriction from thread libraries etc.  -DaveM
455          */
456         csp &= ~7UL;
457
458         distance = fp - psp;
459         rval = (csp - distance);
460         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
461                 rval = 0;
462         else if (test_thread_flag(TIF_32BIT)) {
463                 if (put_user(((u32)csp),
464                              &(((struct reg_window32 __user *)rval)->ins[6])))
465                         rval = 0;
466         } else {
467                 if (put_user(((u64)csp - STACK_BIAS),
468                              &(((struct reg_window __user *)rval)->ins[6])))
469                         rval = 0;
470                 else
471                         rval = rval - STACK_BIAS;
472         }
473
474         return rval;
475 }
476
477 /* Standard stuff. */
478 static inline void shift_window_buffer(int first_win, int last_win,
479                                        struct thread_info *t)
480 {
481         int i;
482
483         for (i = first_win; i < last_win; i++) {
484                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
485                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
486                        sizeof(struct reg_window));
487         }
488 }
489
490 void synchronize_user_stack(void)
491 {
492         struct thread_info *t = current_thread_info();
493         unsigned long window;
494
495         flush_user_windows();
496         if ((window = get_thread_wsaved()) != 0) {
497                 int winsize = sizeof(struct reg_window);
498                 int bias = 0;
499
500                 if (test_thread_flag(TIF_32BIT))
501                         winsize = sizeof(struct reg_window32);
502                 else
503                         bias = STACK_BIAS;
504
505                 window -= 1;
506                 do {
507                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
508                         struct reg_window *rwin = &t->reg_window[window];
509
510                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
511                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
512                                 set_thread_wsaved(get_thread_wsaved() - 1);
513                         }
514                 } while (window--);
515         }
516 }
517
518 static void stack_unaligned(unsigned long sp)
519 {
520         siginfo_t info;
521
522         info.si_signo = SIGBUS;
523         info.si_errno = 0;
524         info.si_code = BUS_ADRALN;
525         info.si_addr = (void __user *) sp;
526         info.si_trapno = 0;
527         force_sig_info(SIGBUS, &info, current);
528 }
529
530 void fault_in_user_windows(void)
531 {
532         struct thread_info *t = current_thread_info();
533         unsigned long window;
534         int winsize = sizeof(struct reg_window);
535         int bias = 0;
536
537         if (test_thread_flag(TIF_32BIT))
538                 winsize = sizeof(struct reg_window32);
539         else
540                 bias = STACK_BIAS;
541
542         flush_user_windows();
543         window = get_thread_wsaved();
544
545         if (likely(window != 0)) {
546                 window -= 1;
547                 do {
548                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
549                         struct reg_window *rwin = &t->reg_window[window];
550
551                         if (unlikely(sp & 0x7UL))
552                                 stack_unaligned(sp);
553
554                         if (unlikely(copy_to_user((char __user *)sp,
555                                                   rwin, winsize)))
556                                 goto barf;
557                 } while (window--);
558         }
559         set_thread_wsaved(0);
560         return;
561
562 barf:
563         set_thread_wsaved(window + 1);
564         do_exit(SIGILL);
565 }
566
567 asmlinkage long sparc_do_fork(unsigned long clone_flags,
568                               unsigned long stack_start,
569                               struct pt_regs *regs,
570                               unsigned long stack_size)
571 {
572         int __user *parent_tid_ptr, *child_tid_ptr;
573         unsigned long orig_i1 = regs->u_regs[UREG_I1];
574         long ret;
575
576 #ifdef CONFIG_COMPAT
577         if (test_thread_flag(TIF_32BIT)) {
578                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
579                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
580         } else
581 #endif
582         {
583                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
584                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
585         }
586
587         ret = do_fork(clone_flags, stack_start,
588                       regs, stack_size,
589                       parent_tid_ptr, child_tid_ptr);
590
591         /* If we get an error and potentially restart the system
592          * call, we're screwed because copy_thread() clobbered
593          * the parent's %o1.  So detect that case and restore it
594          * here.
595          */
596         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
597                 regs->u_regs[UREG_I1] = orig_i1;
598
599         return ret;
600 }
601
602 /* Copy a Sparc thread.  The fork() return value conventions
603  * under SunOS are nothing short of bletcherous:
604  * Parent -->  %o0 == childs  pid, %o1 == 0
605  * Child  -->  %o0 == parents pid, %o1 == 1
606  */
607 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
608                 unsigned long unused,
609                 struct task_struct *p, struct pt_regs *regs)
610 {
611         struct thread_info *t = task_thread_info(p);
612         struct sparc_stackf *parent_sf;
613         unsigned long child_stack_sz;
614         char *child_trap_frame;
615         int kernel_thread;
616
617         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
618         parent_sf = ((struct sparc_stackf *) regs) - 1;
619
620         /* Calculate offset to stack_frame & pt_regs */
621         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
622                           (kernel_thread ? STACKFRAME_SZ : 0));
623         child_trap_frame = (task_stack_page(p) +
624                             (THREAD_SIZE - child_stack_sz));
625         memcpy(child_trap_frame, parent_sf, child_stack_sz);
626
627         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
628                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
629                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
630         t->new_child = 1;
631         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
632         t->kregs = (struct pt_regs *) (child_trap_frame +
633                                        sizeof(struct sparc_stackf));
634         t->fpsaved[0] = 0;
635
636         if (kernel_thread) {
637                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
638                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
639
640                 /* Zero terminate the stack backtrace.  */
641                 child_sf->fp = NULL;
642                 t->kregs->u_regs[UREG_FP] =
643                   ((unsigned long) child_sf) - STACK_BIAS;
644
645                 /* Special case, if we are spawning a kernel thread from
646                  * a userspace task (usermode helper, NFS or similar), we
647                  * must disable performance counters in the child because
648                  * the address space and protection realm are changing.
649                  */
650                 if (t->flags & _TIF_PERFCTR) {
651                         t->user_cntd0 = t->user_cntd1 = NULL;
652                         t->pcr_reg = 0;
653                         t->flags &= ~_TIF_PERFCTR;
654                 }
655                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
656                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
657                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
658         } else {
659                 if (t->flags & _TIF_32BIT) {
660                         sp &= 0x00000000ffffffffUL;
661                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
662                 }
663                 t->kregs->u_regs[UREG_FP] = sp;
664                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
665                 if (sp != regs->u_regs[UREG_FP]) {
666                         unsigned long csp;
667
668                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
669                         if (!csp)
670                                 return -EFAULT;
671                         t->kregs->u_regs[UREG_FP] = csp;
672                 }
673                 if (t->utraps)
674                         t->utraps[0]++;
675         }
676
677         /* Set the return value for the child. */
678         t->kregs->u_regs[UREG_I0] = current->pid;
679         t->kregs->u_regs[UREG_I1] = 1;
680
681         /* Set the second return value for the parent. */
682         regs->u_regs[UREG_I1] = 0;
683
684         if (clone_flags & CLONE_SETTLS)
685                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
686
687         return 0;
688 }
689
690 /*
691  * This is the mechanism for creating a new kernel thread.
692  *
693  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
694  * who haven't done an "execve()") should use this: it will work within
695  * a system call from a "real" process, but the process memory space will
696  * not be freed until both the parent and the child have exited.
697  */
698 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
699 {
700         long retval;
701
702         /* If the parent runs before fn(arg) is called by the child,
703          * the input registers of this function can be clobbered.
704          * So we stash 'fn' and 'arg' into global registers which
705          * will not be modified by the parent.
706          */
707         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
708                              "mov %5, %%g3\n\t"    /* Save ARG into global */
709                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
710                              "mov %2, %%o0\n\t"    /* Clone flags. */
711                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
712                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
713                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
714                              " mov %%o0, %0\n\t"
715                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
716                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
717                              "mov %3, %%g1\n\t"
718                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
719                              /* Notreached by child. */
720                              "1:" :
721                              "=r" (retval) :
722                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
723                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
724                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
725         return retval;
726 }
727
728 typedef struct {
729         union {
730                 unsigned int    pr_regs[32];
731                 unsigned long   pr_dregs[16];
732         } pr_fr;
733         unsigned int __unused;
734         unsigned int    pr_fsr;
735         unsigned char   pr_qcnt;
736         unsigned char   pr_q_entrysize;
737         unsigned char   pr_en;
738         unsigned int    pr_q[64];
739 } elf_fpregset_t32;
740
741 /*
742  * fill in the fpu structure for a core dump.
743  */
744 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
745 {
746         unsigned long *kfpregs = current_thread_info()->fpregs;
747         unsigned long fprs = current_thread_info()->fpsaved[0];
748
749         if (test_thread_flag(TIF_32BIT)) {
750                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
751
752                 if (fprs & FPRS_DL)
753                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
754                                sizeof(unsigned int) * 32);
755                 else
756                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
757                                sizeof(unsigned int) * 32);
758                 fpregs32->pr_qcnt = 0;
759                 fpregs32->pr_q_entrysize = 8;
760                 memset(&fpregs32->pr_q[0], 0,
761                        (sizeof(unsigned int) * 64));
762                 if (fprs & FPRS_FEF) {
763                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
764                         fpregs32->pr_en = 1;
765                 } else {
766                         fpregs32->pr_fsr = 0;
767                         fpregs32->pr_en = 0;
768                 }
769         } else {
770                 if(fprs & FPRS_DL)
771                         memcpy(&fpregs->pr_regs[0], kfpregs,
772                                sizeof(unsigned int) * 32);
773                 else
774                         memset(&fpregs->pr_regs[0], 0,
775                                sizeof(unsigned int) * 32);
776                 if(fprs & FPRS_DU)
777                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
778                                sizeof(unsigned int) * 32);
779                 else
780                         memset(&fpregs->pr_regs[16], 0,
781                                sizeof(unsigned int) * 32);
782                 if(fprs & FPRS_FEF) {
783                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
784                         fpregs->pr_gsr = current_thread_info()->gsr[0];
785                 } else {
786                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
787                 }
788                 fpregs->pr_fprs = fprs;
789         }
790         return 1;
791 }
792
793 /*
794  * sparc_execve() executes a new program after the asm stub has set
795  * things up for us.  This should basically do what I want it to.
796  */
797 asmlinkage int sparc_execve(struct pt_regs *regs)
798 {
799         int error, base = 0;
800         char *filename;
801
802         /* User register window flush is done by entry.S */
803
804         /* Check for indirect call. */
805         if (regs->u_regs[UREG_G1] == 0)
806                 base = 1;
807
808         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
809         error = PTR_ERR(filename);
810         if (IS_ERR(filename))
811                 goto out;
812         error = do_execve(filename,
813                           (char __user * __user *)
814                           regs->u_regs[base + UREG_I1],
815                           (char __user * __user *)
816                           regs->u_regs[base + UREG_I2], regs);
817         putname(filename);
818         if (!error) {
819                 fprs_write(0);
820                 current_thread_info()->xfsr[0] = 0;
821                 current_thread_info()->fpsaved[0] = 0;
822                 regs->tstate &= ~TSTATE_PEF;
823         }
824 out:
825         return error;
826 }
827
828 unsigned long get_wchan(struct task_struct *task)
829 {
830         unsigned long pc, fp, bias = 0;
831         unsigned long thread_info_base;
832         struct reg_window *rw;
833         unsigned long ret = 0;
834         int count = 0; 
835
836         if (!task || task == current ||
837             task->state == TASK_RUNNING)
838                 goto out;
839
840         thread_info_base = (unsigned long) task_stack_page(task);
841         bias = STACK_BIAS;
842         fp = task_thread_info(task)->ksp + bias;
843
844         do {
845                 /* Bogus frame pointer? */
846                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
847                     fp >= (thread_info_base + THREAD_SIZE))
848                         break;
849                 rw = (struct reg_window *) fp;
850                 pc = rw->ins[7];
851                 if (!in_sched_functions(pc)) {
852                         ret = pc;
853                         goto out;
854                 }
855                 fp = rw->ins[6] + bias;
856         } while (++count < 16);
857
858 out:
859         return ret;
860 }