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