066e253f9c124fd1c29de3a42f2ee14ffa41ac8d
[linux-2.6.git] / arch / sparc / kernel / process.c
1 /*  $Id: process.c,v 1.161 2002/01/23 11:27:32 davem Exp $
2  *  linux/arch/sparc/kernel/process.c
3  *
4  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5  *  Copyright (C) 1996 Eddie C. Dost   (ecd@skynet.be)
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/kallsyms.h>
19 #include <linux/mm.h>
20 #include <linux/stddef.h>
21 #include <linux/ptrace.h>
22 #include <linux/slab.h>
23 #include <linux/user.h>
24 #include <linux/a.out.h>
25 #include <linux/config.h>
26 #include <linux/smp.h>
27 #include <linux/smp_lock.h>
28 #include <linux/reboot.h>
29 #include <linux/delay.h>
30 #include <linux/pm.h>
31 #include <linux/init.h>
32
33 #include <asm/auxio.h>
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/delay.h>
41 #include <asm/processor.h>
42 #include <asm/psr.h>
43 #include <asm/elf.h>
44 #include <asm/unistd.h>
45
46 /* 
47  * Power management idle function 
48  * Set in pm platform drivers (apc.c and pmc.c)
49  */
50 void (*pm_idle)(void);
51
52 /* 
53  * Power-off handler instantiation for pm.h compliance
54  * This is done via auxio, but could be used as a fallback
55  * handler when auxio is not present-- unused for now...
56  */
57 void (*pm_power_off)(void);
58
59 /*
60  * sysctl - toggle power-off restriction for serial console 
61  * systems in machine_power_off()
62  */
63 int scons_pwroff = 1;
64
65 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
66
67 struct task_struct *last_task_used_math = NULL;
68 struct thread_info *current_set[NR_CPUS];
69
70 /*
71  * default_idle is new in 2.5. XXX Review, currently stolen from sparc64.
72  */
73 void default_idle(void)
74 {
75 }
76
77 #ifndef CONFIG_SMP
78
79 #define SUN4C_FAULT_HIGH 100
80
81 /*
82  * the idle loop on a Sparc... ;)
83  */
84 void cpu_idle(void)
85 {
86         if (current->pid != 0)
87                 goto out;
88
89         /* endless idle loop with no priority at all */
90         for (;;) {
91                 if (ARCH_SUN4C_SUN4) {
92                         static int count = HZ;
93                         static unsigned long last_jiffies;
94                         static unsigned long last_faults;
95                         static unsigned long fps;
96                         unsigned long now;
97                         unsigned long faults;
98                         unsigned long flags;
99
100                         extern unsigned long sun4c_kernel_faults;
101                         extern void sun4c_grow_kernel_ring(void);
102
103                         local_irq_save(flags);
104                         now = jiffies;
105                         count -= (now - last_jiffies);
106                         last_jiffies = now;
107                         if (count < 0) {
108                                 count += HZ;
109                                 faults = sun4c_kernel_faults;
110                                 fps = (fps + (faults - last_faults)) >> 1;
111                                 last_faults = faults;
112 #if 0
113                                 printk("kernel faults / second = %ld\n", fps);
114 #endif
115                                 if (fps >= SUN4C_FAULT_HIGH) {
116                                         sun4c_grow_kernel_ring();
117                                 }
118                         }
119                         local_irq_restore(flags);
120                 }
121
122                 while((!need_resched()) && pm_idle) {
123                         (*pm_idle)();
124                 }
125
126                 schedule();
127                 check_pgt_cache();
128         }
129 out:
130         return;
131 }
132
133 #else
134
135 /* This is being executed in task 0 'user space'. */
136 void cpu_idle(void)
137 {
138         /* endless idle loop with no priority at all */
139         while(1) {
140                 if(need_resched()) {
141                         schedule();
142                         check_pgt_cache();
143                 }
144                 barrier(); /* or else gcc optimizes... */
145         }
146 }
147
148 #endif
149
150 extern char reboot_command [];
151
152 extern void (*prom_palette)(int);
153
154 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
155 void machine_halt(void)
156 {
157         local_irq_enable();
158         mdelay(8);
159         local_irq_disable();
160         if (!serial_console && prom_palette)
161                 prom_palette (1);
162         prom_halt();
163         panic("Halt failed!");
164 }
165
166 EXPORT_SYMBOL(machine_halt);
167
168 void machine_restart(char * cmd)
169 {
170         char *p;
171         
172         local_irq_enable();
173         mdelay(8);
174         local_irq_disable();
175
176         p = strchr (reboot_command, '\n');
177         if (p) *p = 0;
178         if (!serial_console && prom_palette)
179                 prom_palette (1);
180         if (cmd)
181                 prom_reboot(cmd);
182         if (*reboot_command)
183                 prom_reboot(reboot_command);
184         prom_feval ("reset");
185         panic("Reboot failed!");
186 }
187
188 EXPORT_SYMBOL(machine_restart);
189
190 void machine_power_off(void)
191 {
192 #ifdef CONFIG_SUN_AUXIO
193         if (auxio_power_register && (!serial_console || scons_pwroff))
194                 *auxio_power_register |= AUXIO_POWER_OFF;
195 #endif
196         machine_halt();
197 }
198
199 EXPORT_SYMBOL(machine_power_off);
200
201 static DEFINE_SPINLOCK(sparc_backtrace_lock);
202
203 void __show_backtrace(unsigned long fp)
204 {
205         struct reg_window *rw;
206         unsigned long flags;
207         int cpu = smp_processor_id();
208
209         spin_lock_irqsave(&sparc_backtrace_lock, flags);
210
211         rw = (struct reg_window *)fp;
212         while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
213             !(((unsigned long) rw) & 0x7)) {
214                 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
215                        "FP[%08lx] CALLER[%08lx]: ", cpu,
216                        rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
217                        rw->ins[4], rw->ins[5],
218                        rw->ins[6],
219                        rw->ins[7]);
220                 print_symbol("%s\n", rw->ins[7]);
221                 rw = (struct reg_window *) rw->ins[6];
222         }
223         spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
224 }
225
226 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
227 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
228 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
229
230 void show_backtrace(void)
231 {
232         unsigned long fp;
233
234         __SAVE; __SAVE; __SAVE; __SAVE;
235         __SAVE; __SAVE; __SAVE; __SAVE;
236         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
237         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
238
239         __GET_FP(fp);
240
241         __show_backtrace(fp);
242 }
243
244 #ifdef CONFIG_SMP
245 void smp_show_backtrace_all_cpus(void)
246 {
247         xc0((smpfunc_t) show_backtrace);
248         show_backtrace();
249 }
250 #endif
251
252 #if 0
253 void show_stackframe(struct sparc_stackf *sf)
254 {
255         unsigned long size;
256         unsigned long *stk;
257         int i;
258
259         printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
260                "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
261                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
262                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
263         printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
264                "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
265                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
266                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
267         printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
268                "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
269                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
270                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
271                sf->xxargs[0]);
272         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
273         size -= STACKFRAME_SZ;
274         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
275         i = 0;
276         do {
277                 printk("s%d: %08lx\n", i++, *stk++);
278         } while ((size -= sizeof(unsigned long)));
279 }
280 #endif
281
282 void show_regs(struct pt_regs *r)
283 {
284         struct reg_window *rw = (struct reg_window *) r->u_regs[14];
285
286         printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx    %s\n",
287                r->psr, r->pc, r->npc, r->y, print_tainted());
288         print_symbol("PC: <%s>\n", r->pc);
289         printk("%%G: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
290                r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
291                r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
292         printk("%%O: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
293                r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
294                r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
295         print_symbol("RPC: <%s>\n", r->u_regs[15]);
296
297         printk("%%L: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
298                rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
299                rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
300         printk("%%I: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
301                rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
302                rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
303 }
304
305 /*
306  * The show_stack is an external API which we do not use ourselves.
307  * The oops is printed in die_if_kernel.
308  */
309 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
310 {
311         unsigned long pc, fp;
312         unsigned long task_base;
313         struct reg_window *rw;
314         int count = 0;
315
316         if (tsk != NULL)
317                 task_base = (unsigned long) tsk->thread_info;
318         else
319                 task_base = (unsigned long) current_thread_info();
320
321         fp = (unsigned long) _ksp;
322         do {
323                 /* Bogus frame pointer? */
324                 if (fp < (task_base + sizeof(struct thread_info)) ||
325                     fp >= (task_base + (PAGE_SIZE << 1)))
326                         break;
327                 rw = (struct reg_window *) fp;
328                 pc = rw->ins[7];
329                 printk("[%08lx : ", pc);
330                 print_symbol("%s ] ", pc);
331                 fp = rw->ins[6];
332         } while (++count < 16);
333         printk("\n");
334 }
335
336 void dump_stack(void)
337 {
338         unsigned long *ksp;
339
340         __asm__ __volatile__("mov       %%fp, %0"
341                              : "=r" (ksp));
342         show_stack(current, ksp);
343 }
344
345 EXPORT_SYMBOL(dump_stack);
346
347 /*
348  * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
349  */
350 unsigned long thread_saved_pc(struct task_struct *tsk)
351 {
352         return tsk->thread_info->kpc;
353 }
354
355 /*
356  * Free current thread data structures etc..
357  */
358 void exit_thread(void)
359 {
360 #ifndef CONFIG_SMP
361         if(last_task_used_math == current) {
362 #else
363         if(current_thread_info()->flags & _TIF_USEDFPU) {
364 #endif
365                 /* Keep process from leaving FPU in a bogon state. */
366                 put_psr(get_psr() | PSR_EF);
367                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
368                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
369 #ifndef CONFIG_SMP
370                 last_task_used_math = NULL;
371 #else
372                 current_thread_info()->flags &= ~_TIF_USEDFPU;
373 #endif
374         }
375 }
376
377 void flush_thread(void)
378 {
379         current_thread_info()->w_saved = 0;
380
381         /* No new signal delivery by default */
382         current->thread.new_signal = 0;
383 #ifndef CONFIG_SMP
384         if(last_task_used_math == current) {
385 #else
386         if(current_thread_info()->flags & _TIF_USEDFPU) {
387 #endif
388                 /* Clean the fpu. */
389                 put_psr(get_psr() | PSR_EF);
390                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
391                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
392 #ifndef CONFIG_SMP
393                 last_task_used_math = NULL;
394 #else
395                 current_thread_info()->flags &= ~_TIF_USEDFPU;
396 #endif
397         }
398
399         /* Now, this task is no longer a kernel thread. */
400         current->thread.current_ds = USER_DS;
401         if (current->thread.flags & SPARC_FLAG_KTHREAD) {
402                 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
403
404                 /* We must fixup kregs as well. */
405                 /* XXX This was not fixed for ti for a while, worked. Unused? */
406                 current->thread.kregs = (struct pt_regs *)
407                     ((char *)current->thread_info + (THREAD_SIZE - TRACEREG_SZ));
408         }
409 }
410
411 static __inline__ struct sparc_stackf __user *
412 clone_stackframe(struct sparc_stackf __user *dst,
413                  struct sparc_stackf __user *src)
414 {
415         unsigned long size, fp;
416         struct sparc_stackf *tmp;
417         struct sparc_stackf __user *sp;
418
419         if (get_user(tmp, &src->fp))
420                 return NULL;
421
422         fp = (unsigned long) tmp;
423         size = (fp - ((unsigned long) src));
424         fp = (unsigned long) dst;
425         sp = (struct sparc_stackf __user *)(fp - size); 
426
427         /* do_fork() grabs the parent semaphore, we must release it
428          * temporarily so we can build the child clone stack frame
429          * without deadlocking.
430          */
431         if (__copy_user(sp, src, size))
432                 sp = NULL;
433         else if (put_user(fp, &sp->fp))
434                 sp = NULL;
435
436         return sp;
437 }
438
439 asmlinkage int sparc_do_fork(unsigned long clone_flags,
440                              unsigned long stack_start,
441                              struct pt_regs *regs,
442                              unsigned long stack_size)
443 {
444         unsigned long parent_tid_ptr, child_tid_ptr;
445
446         parent_tid_ptr = regs->u_regs[UREG_I2];
447         child_tid_ptr = regs->u_regs[UREG_I4];
448
449         return do_fork(clone_flags, stack_start,
450                        regs, stack_size,
451                        (int __user *) parent_tid_ptr,
452                        (int __user *) child_tid_ptr);
453 }
454
455 /* Copy a Sparc thread.  The fork() return value conventions
456  * under SunOS are nothing short of bletcherous:
457  * Parent -->  %o0 == childs  pid, %o1 == 0
458  * Child  -->  %o0 == parents pid, %o1 == 1
459  *
460  * NOTE: We have a separate fork kpsr/kwim because
461  *       the parent could change these values between
462  *       sys_fork invocation and when we reach here
463  *       if the parent should sleep while trying to
464  *       allocate the task_struct and kernel stack in
465  *       do_fork().
466  * XXX See comment above sys_vfork in sparc64. todo.
467  */
468 extern void ret_from_fork(void);
469
470 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
471                 unsigned long unused,
472                 struct task_struct *p, struct pt_regs *regs)
473 {
474         struct thread_info *ti = p->thread_info;
475         struct pt_regs *childregs;
476         char *new_stack;
477
478 #ifndef CONFIG_SMP
479         if(last_task_used_math == current) {
480 #else
481         if(current_thread_info()->flags & _TIF_USEDFPU) {
482 #endif
483                 put_psr(get_psr() | PSR_EF);
484                 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
485                        &p->thread.fpqueue[0], &p->thread.fpqdepth);
486 #ifdef CONFIG_SMP
487                 current_thread_info()->flags &= ~_TIF_USEDFPU;
488 #endif
489         }
490
491         /*
492          *  p->thread_info         new_stack   childregs
493          *  !                      !           !             {if(PSR_PS) }
494          *  V                      V (stk.fr.) V  (pt_regs)  { (stk.fr.) }
495          *  +----- - - - - - ------+===========+============={+==========}+
496          */
497         new_stack = (char*)ti + THREAD_SIZE;
498         if (regs->psr & PSR_PS)
499                 new_stack -= STACKFRAME_SZ;
500         new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
501         memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
502         childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
503
504         /*
505          * A new process must start with interrupts closed in 2.5,
506          * because this is how Mingo's scheduler works (see schedule_tail
507          * and finish_arch_switch). If we do not do it, a timer interrupt hits
508          * before we unlock, attempts to re-take the rq->lock, and then we die.
509          * Thus, kpsr|=PSR_PIL.
510          */
511         ti->ksp = (unsigned long) new_stack;
512         ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
513         ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
514         ti->kwim = current->thread.fork_kwim;
515
516         if(regs->psr & PSR_PS) {
517                 extern struct pt_regs fake_swapper_regs;
518
519                 p->thread.kregs = &fake_swapper_regs;
520                 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
521                 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
522                 p->thread.flags |= SPARC_FLAG_KTHREAD;
523                 p->thread.current_ds = KERNEL_DS;
524                 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
525                 childregs->u_regs[UREG_G6] = (unsigned long) ti;
526         } else {
527                 p->thread.kregs = childregs;
528                 childregs->u_regs[UREG_FP] = sp;
529                 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
530                 p->thread.current_ds = USER_DS;
531
532                 if (sp != regs->u_regs[UREG_FP]) {
533                         struct sparc_stackf __user *childstack;
534                         struct sparc_stackf __user *parentstack;
535
536                         /*
537                          * This is a clone() call with supplied user stack.
538                          * Set some valid stack frames to give to the child.
539                          */
540                         childstack = (struct sparc_stackf __user *)
541                                 (sp & ~0x7UL);
542                         parentstack = (struct sparc_stackf __user *)
543                                 regs->u_regs[UREG_FP];
544
545 #if 0
546                         printk("clone: parent stack:\n");
547                         show_stackframe(parentstack);
548 #endif
549
550                         childstack = clone_stackframe(childstack, parentstack);
551                         if (!childstack)
552                                 return -EFAULT;
553
554 #if 0
555                         printk("clone: child stack:\n");
556                         show_stackframe(childstack);
557 #endif
558
559                         childregs->u_regs[UREG_FP] = (unsigned long)childstack;
560                 }
561         }
562
563 #ifdef CONFIG_SMP
564         /* FPU must be disabled on SMP. */
565         childregs->psr &= ~PSR_EF;
566 #endif
567
568         /* Set the return value for the child. */
569         childregs->u_regs[UREG_I0] = current->pid;
570         childregs->u_regs[UREG_I1] = 1;
571
572         /* Set the return value for the parent. */
573         regs->u_regs[UREG_I1] = 0;
574
575         if (clone_flags & CLONE_SETTLS)
576                 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
577
578         return 0;
579 }
580
581 /*
582  * fill in the user structure for a core dump..
583  */
584 void dump_thread(struct pt_regs * regs, struct user * dump)
585 {
586         unsigned long first_stack_page;
587
588         dump->magic = SUNOS_CORE_MAGIC;
589         dump->len = sizeof(struct user);
590         dump->regs.psr = regs->psr;
591         dump->regs.pc = regs->pc;
592         dump->regs.npc = regs->npc;
593         dump->regs.y = regs->y;
594         /* fuck me plenty */
595         memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
596         dump->uexec = current->thread.core_exec;
597         dump->u_tsize = (((unsigned long) current->mm->end_code) -
598                 ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
599         dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
600         dump->u_dsize -= dump->u_tsize;
601         dump->u_dsize &= ~(PAGE_SIZE - 1);
602         first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
603         dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
604         memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
605         dump->fpu.fpstatus.fsr = current->thread.fsr;
606         dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
607         dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth;
608         memcpy(&dump->fpu.fpstatus.fpq[0], &current->thread.fpqueue[0],
609                ((sizeof(unsigned long) * 2) * 16));
610         dump->sigcode = 0;
611 }
612
613 /*
614  * fill in the fpu structure for a core dump.
615  */
616 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
617 {
618         if (used_math()) {
619                 memset(fpregs, 0, sizeof(*fpregs));
620                 fpregs->pr_q_entrysize = 8;
621                 return 1;
622         }
623 #ifdef CONFIG_SMP
624         if (current_thread_info()->flags & _TIF_USEDFPU) {
625                 put_psr(get_psr() | PSR_EF);
626                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
627                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
628                 if (regs != NULL) {
629                         regs->psr &= ~(PSR_EF);
630                         current_thread_info()->flags &= ~(_TIF_USEDFPU);
631                 }
632         }
633 #else
634         if (current == last_task_used_math) {
635                 put_psr(get_psr() | PSR_EF);
636                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
637                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
638                 if (regs != NULL) {
639                         regs->psr &= ~(PSR_EF);
640                         last_task_used_math = NULL;
641                 }
642         }
643 #endif
644         memcpy(&fpregs->pr_fr.pr_regs[0],
645                &current->thread.float_regs[0],
646                (sizeof(unsigned long) * 32));
647         fpregs->pr_fsr = current->thread.fsr;
648         fpregs->pr_qcnt = current->thread.fpqdepth;
649         fpregs->pr_q_entrysize = 8;
650         fpregs->pr_en = 1;
651         if(fpregs->pr_qcnt != 0) {
652                 memcpy(&fpregs->pr_q[0],
653                        &current->thread.fpqueue[0],
654                        sizeof(struct fpq) * fpregs->pr_qcnt);
655         }
656         /* Zero out the rest. */
657         memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
658                sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
659         return 1;
660 }
661
662 /*
663  * sparc_execve() executes a new program after the asm stub has set
664  * things up for us.  This should basically do what I want it to.
665  */
666 asmlinkage int sparc_execve(struct pt_regs *regs)
667 {
668         int error, base = 0;
669         char *filename;
670
671         /* Check for indirect call. */
672         if(regs->u_regs[UREG_G1] == 0)
673                 base = 1;
674
675         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
676         error = PTR_ERR(filename);
677         if(IS_ERR(filename))
678                 goto out;
679         error = do_execve(filename,
680                           (char __user * __user *)regs->u_regs[base + UREG_I1],
681                           (char __user * __user *)regs->u_regs[base + UREG_I2],
682                           regs);
683         putname(filename);
684         if (error == 0) {
685                 task_lock(current);
686                 current->ptrace &= ~PT_DTRACE;
687                 task_unlock(current);
688         }
689 out:
690         return error;
691 }
692
693 /*
694  * This is the mechanism for creating a new kernel thread.
695  *
696  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
697  * who haven't done an "execve()") should use this: it will work within
698  * a system call from a "real" process, but the process memory space will
699  * not be free'd until both the parent and the child have exited.
700  */
701 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
702 {
703         long retval;
704
705         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Set aside fn ptr... */
706                              "mov %5, %%g3\n\t"    /* and arg. */
707                              "mov %1, %%g1\n\t"
708                              "mov %2, %%o0\n\t"    /* Clone flags. */
709                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
710                              "t 0x10\n\t"          /* Linux/Sparc clone(). */
711                              "cmp %%o1, 0\n\t"
712                              "be 1f\n\t"           /* The parent, just return. */
713                              " nop\n\t"            /* Delay slot. */
714                              "jmpl %%g2, %%o7\n\t" /* Call the function. */
715                              " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
716                              "mov %3, %%g1\n\t"
717                              "t 0x10\n\t"          /* Linux/Sparc exit(). */
718                              /* Notreached by child. */
719                              "1: mov %%o0, %0\n\t" :
720                              "=r" (retval) :
721                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
722                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
723                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
724         return retval;
725 }
726
727 unsigned long get_wchan(struct task_struct *task)
728 {
729         unsigned long pc, fp, bias = 0;
730         unsigned long task_base = (unsigned long) task;
731         unsigned long ret = 0;
732         struct reg_window *rw;
733         int count = 0;
734
735         if (!task || task == current ||
736             task->state == TASK_RUNNING)
737                 goto out;
738
739         fp = task->thread_info->ksp + bias;
740         do {
741                 /* Bogus frame pointer? */
742                 if (fp < (task_base + sizeof(struct thread_info)) ||
743                     fp >= (task_base + (2 * PAGE_SIZE)))
744                         break;
745                 rw = (struct reg_window *) fp;
746                 pc = rw->ins[7];
747                 if (!in_sched_functions(pc)) {
748                         ret = pc;
749                         goto out;
750                 }
751                 fp = rw->ins[6] + bias;
752         } while (++count < 16);
753
754 out:
755         return ret;
756 }
757