c39f4d01096d7cac71d22c39981152ede994ebb4
[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         /* endless idle loop with no priority at all */
87         for (;;) {
88                 if (ARCH_SUN4C_SUN4) {
89                         static int count = HZ;
90                         static unsigned long last_jiffies;
91                         static unsigned long last_faults;
92                         static unsigned long fps;
93                         unsigned long now;
94                         unsigned long faults;
95                         unsigned long flags;
96
97                         extern unsigned long sun4c_kernel_faults;
98                         extern void sun4c_grow_kernel_ring(void);
99
100                         local_irq_save(flags);
101                         now = jiffies;
102                         count -= (now - last_jiffies);
103                         last_jiffies = now;
104                         if (count < 0) {
105                                 count += HZ;
106                                 faults = sun4c_kernel_faults;
107                                 fps = (fps + (faults - last_faults)) >> 1;
108                                 last_faults = faults;
109 #if 0
110                                 printk("kernel faults / second = %ld\n", fps);
111 #endif
112                                 if (fps >= SUN4C_FAULT_HIGH) {
113                                         sun4c_grow_kernel_ring();
114                                 }
115                         }
116                         local_irq_restore(flags);
117                 }
118
119                 while((!need_resched()) && pm_idle) {
120                         (*pm_idle)();
121                 }
122
123                 preempt_enable_no_resched();
124                 schedule();
125                 preempt_disable();
126                 check_pgt_cache();
127         }
128 }
129
130 #else
131
132 /* This is being executed in task 0 'user space'. */
133 void cpu_idle(void)
134 {
135         /* endless idle loop with no priority at all */
136         while(1) {
137                 if(need_resched()) {
138                         preempt_enable_no_resched();
139                         schedule();
140                         preempt_disable();
141                         check_pgt_cache();
142                 }
143                 barrier(); /* or else gcc optimizes... */
144         }
145 }
146
147 #endif
148
149 extern char reboot_command [];
150
151 extern void (*prom_palette)(int);
152
153 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
154 void machine_halt(void)
155 {
156         local_irq_enable();
157         mdelay(8);
158         local_irq_disable();
159         if (!serial_console && prom_palette)
160                 prom_palette (1);
161         prom_halt();
162         panic("Halt failed!");
163 }
164
165 void machine_restart(char * cmd)
166 {
167         char *p;
168         
169         local_irq_enable();
170         mdelay(8);
171         local_irq_disable();
172
173         p = strchr (reboot_command, '\n');
174         if (p) *p = 0;
175         if (!serial_console && prom_palette)
176                 prom_palette (1);
177         if (cmd)
178                 prom_reboot(cmd);
179         if (*reboot_command)
180                 prom_reboot(reboot_command);
181         prom_feval ("reset");
182         panic("Reboot failed!");
183 }
184
185 void machine_power_off(void)
186 {
187 #ifdef CONFIG_SUN_AUXIO
188         if (auxio_power_register && (!serial_console || scons_pwroff))
189                 *auxio_power_register |= AUXIO_POWER_OFF;
190 #endif
191         machine_halt();
192 }
193
194 static DEFINE_SPINLOCK(sparc_backtrace_lock);
195
196 void __show_backtrace(unsigned long fp)
197 {
198         struct reg_window *rw;
199         unsigned long flags;
200         int cpu = smp_processor_id();
201
202         spin_lock_irqsave(&sparc_backtrace_lock, flags);
203
204         rw = (struct reg_window *)fp;
205         while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
206             !(((unsigned long) rw) & 0x7)) {
207                 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
208                        "FP[%08lx] CALLER[%08lx]: ", cpu,
209                        rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
210                        rw->ins[4], rw->ins[5],
211                        rw->ins[6],
212                        rw->ins[7]);
213                 print_symbol("%s\n", rw->ins[7]);
214                 rw = (struct reg_window *) rw->ins[6];
215         }
216         spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
217 }
218
219 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
220 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
221 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
222
223 void show_backtrace(void)
224 {
225         unsigned long fp;
226
227         __SAVE; __SAVE; __SAVE; __SAVE;
228         __SAVE; __SAVE; __SAVE; __SAVE;
229         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
230         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
231
232         __GET_FP(fp);
233
234         __show_backtrace(fp);
235 }
236
237 #ifdef CONFIG_SMP
238 void smp_show_backtrace_all_cpus(void)
239 {
240         xc0((smpfunc_t) show_backtrace);
241         show_backtrace();
242 }
243 #endif
244
245 #if 0
246 void show_stackframe(struct sparc_stackf *sf)
247 {
248         unsigned long size;
249         unsigned long *stk;
250         int i;
251
252         printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
253                "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
254                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
255                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
256         printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
257                "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
258                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
259                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
260         printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
261                "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
262                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
263                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
264                sf->xxargs[0]);
265         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
266         size -= STACKFRAME_SZ;
267         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
268         i = 0;
269         do {
270                 printk("s%d: %08lx\n", i++, *stk++);
271         } while ((size -= sizeof(unsigned long)));
272 }
273 #endif
274
275 void show_regs(struct pt_regs *r)
276 {
277         struct reg_window *rw = (struct reg_window *) r->u_regs[14];
278
279         printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx    %s\n",
280                r->psr, r->pc, r->npc, r->y, print_tainted());
281         print_symbol("PC: <%s>\n", r->pc);
282         printk("%%G: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
283                r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
284                r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
285         printk("%%O: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
286                r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
287                r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
288         print_symbol("RPC: <%s>\n", r->u_regs[15]);
289
290         printk("%%L: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
291                rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
292                rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
293         printk("%%I: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
294                rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
295                rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
296 }
297
298 /*
299  * The show_stack is an external API which we do not use ourselves.
300  * The oops is printed in die_if_kernel.
301  */
302 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
303 {
304         unsigned long pc, fp;
305         unsigned long task_base;
306         struct reg_window *rw;
307         int count = 0;
308
309         if (tsk != NULL)
310                 task_base = (unsigned long) tsk->thread_info;
311         else
312                 task_base = (unsigned long) current_thread_info();
313
314         fp = (unsigned long) _ksp;
315         do {
316                 /* Bogus frame pointer? */
317                 if (fp < (task_base + sizeof(struct thread_info)) ||
318                     fp >= (task_base + (PAGE_SIZE << 1)))
319                         break;
320                 rw = (struct reg_window *) fp;
321                 pc = rw->ins[7];
322                 printk("[%08lx : ", pc);
323                 print_symbol("%s ] ", pc);
324                 fp = rw->ins[6];
325         } while (++count < 16);
326         printk("\n");
327 }
328
329 void dump_stack(void)
330 {
331         unsigned long *ksp;
332
333         __asm__ __volatile__("mov       %%fp, %0"
334                              : "=r" (ksp));
335         show_stack(current, ksp);
336 }
337
338 EXPORT_SYMBOL(dump_stack);
339
340 /*
341  * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
342  */
343 unsigned long thread_saved_pc(struct task_struct *tsk)
344 {
345         return tsk->thread_info->kpc;
346 }
347
348 /*
349  * Free current thread data structures etc..
350  */
351 void exit_thread(void)
352 {
353 #ifndef CONFIG_SMP
354         if(last_task_used_math == current) {
355 #else
356         if(current_thread_info()->flags & _TIF_USEDFPU) {
357 #endif
358                 /* Keep process from leaving FPU in a bogon state. */
359                 put_psr(get_psr() | PSR_EF);
360                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
361                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
362 #ifndef CONFIG_SMP
363                 last_task_used_math = NULL;
364 #else
365                 current_thread_info()->flags &= ~_TIF_USEDFPU;
366 #endif
367         }
368 }
369
370 void flush_thread(void)
371 {
372         current_thread_info()->w_saved = 0;
373
374         /* No new signal delivery by default */
375         current->thread.new_signal = 0;
376 #ifndef CONFIG_SMP
377         if(last_task_used_math == current) {
378 #else
379         if(current_thread_info()->flags & _TIF_USEDFPU) {
380 #endif
381                 /* Clean the fpu. */
382                 put_psr(get_psr() | PSR_EF);
383                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
384                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
385 #ifndef CONFIG_SMP
386                 last_task_used_math = NULL;
387 #else
388                 current_thread_info()->flags &= ~_TIF_USEDFPU;
389 #endif
390         }
391
392         /* Now, this task is no longer a kernel thread. */
393         current->thread.current_ds = USER_DS;
394         if (current->thread.flags & SPARC_FLAG_KTHREAD) {
395                 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
396
397                 /* We must fixup kregs as well. */
398                 /* XXX This was not fixed for ti for a while, worked. Unused? */
399                 current->thread.kregs = (struct pt_regs *)
400                     ((char *)current->thread_info + (THREAD_SIZE - TRACEREG_SZ));
401         }
402 }
403
404 static __inline__ struct sparc_stackf __user *
405 clone_stackframe(struct sparc_stackf __user *dst,
406                  struct sparc_stackf __user *src)
407 {
408         unsigned long size, fp;
409         struct sparc_stackf *tmp;
410         struct sparc_stackf __user *sp;
411
412         if (get_user(tmp, &src->fp))
413                 return NULL;
414
415         fp = (unsigned long) tmp;
416         size = (fp - ((unsigned long) src));
417         fp = (unsigned long) dst;
418         sp = (struct sparc_stackf __user *)(fp - size); 
419
420         /* do_fork() grabs the parent semaphore, we must release it
421          * temporarily so we can build the child clone stack frame
422          * without deadlocking.
423          */
424         if (__copy_user(sp, src, size))
425                 sp = NULL;
426         else if (put_user(fp, &sp->fp))
427                 sp = NULL;
428
429         return sp;
430 }
431
432 asmlinkage int sparc_do_fork(unsigned long clone_flags,
433                              unsigned long stack_start,
434                              struct pt_regs *regs,
435                              unsigned long stack_size)
436 {
437         unsigned long parent_tid_ptr, child_tid_ptr;
438
439         parent_tid_ptr = regs->u_regs[UREG_I2];
440         child_tid_ptr = regs->u_regs[UREG_I4];
441
442         return do_fork(clone_flags, stack_start,
443                        regs, stack_size,
444                        (int __user *) parent_tid_ptr,
445                        (int __user *) child_tid_ptr);
446 }
447
448 /* Copy a Sparc thread.  The fork() return value conventions
449  * under SunOS are nothing short of bletcherous:
450  * Parent -->  %o0 == childs  pid, %o1 == 0
451  * Child  -->  %o0 == parents pid, %o1 == 1
452  *
453  * NOTE: We have a separate fork kpsr/kwim because
454  *       the parent could change these values between
455  *       sys_fork invocation and when we reach here
456  *       if the parent should sleep while trying to
457  *       allocate the task_struct and kernel stack in
458  *       do_fork().
459  * XXX See comment above sys_vfork in sparc64. todo.
460  */
461 extern void ret_from_fork(void);
462
463 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
464                 unsigned long unused,
465                 struct task_struct *p, struct pt_regs *regs)
466 {
467         struct thread_info *ti = p->thread_info;
468         struct pt_regs *childregs;
469         char *new_stack;
470
471 #ifndef CONFIG_SMP
472         if(last_task_used_math == current) {
473 #else
474         if(current_thread_info()->flags & _TIF_USEDFPU) {
475 #endif
476                 put_psr(get_psr() | PSR_EF);
477                 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
478                        &p->thread.fpqueue[0], &p->thread.fpqdepth);
479 #ifdef CONFIG_SMP
480                 current_thread_info()->flags &= ~_TIF_USEDFPU;
481 #endif
482         }
483
484         /*
485          *  p->thread_info         new_stack   childregs
486          *  !                      !           !             {if(PSR_PS) }
487          *  V                      V (stk.fr.) V  (pt_regs)  { (stk.fr.) }
488          *  +----- - - - - - ------+===========+============={+==========}+
489          */
490         new_stack = (char*)ti + THREAD_SIZE;
491         if (regs->psr & PSR_PS)
492                 new_stack -= STACKFRAME_SZ;
493         new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
494         memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
495         childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
496
497         /*
498          * A new process must start with interrupts closed in 2.5,
499          * because this is how Mingo's scheduler works (see schedule_tail
500          * and finish_arch_switch). If we do not do it, a timer interrupt hits
501          * before we unlock, attempts to re-take the rq->lock, and then we die.
502          * Thus, kpsr|=PSR_PIL.
503          */
504         ti->ksp = (unsigned long) new_stack;
505         ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
506         ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
507         ti->kwim = current->thread.fork_kwim;
508
509         if(regs->psr & PSR_PS) {
510                 extern struct pt_regs fake_swapper_regs;
511
512                 p->thread.kregs = &fake_swapper_regs;
513                 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
514                 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
515                 p->thread.flags |= SPARC_FLAG_KTHREAD;
516                 p->thread.current_ds = KERNEL_DS;
517                 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
518                 childregs->u_regs[UREG_G6] = (unsigned long) ti;
519         } else {
520                 p->thread.kregs = childregs;
521                 childregs->u_regs[UREG_FP] = sp;
522                 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
523                 p->thread.current_ds = USER_DS;
524
525                 if (sp != regs->u_regs[UREG_FP]) {
526                         struct sparc_stackf __user *childstack;
527                         struct sparc_stackf __user *parentstack;
528
529                         /*
530                          * This is a clone() call with supplied user stack.
531                          * Set some valid stack frames to give to the child.
532                          */
533                         childstack = (struct sparc_stackf __user *)
534                                 (sp & ~0x7UL);
535                         parentstack = (struct sparc_stackf __user *)
536                                 regs->u_regs[UREG_FP];
537
538 #if 0
539                         printk("clone: parent stack:\n");
540                         show_stackframe(parentstack);
541 #endif
542
543                         childstack = clone_stackframe(childstack, parentstack);
544                         if (!childstack)
545                                 return -EFAULT;
546
547 #if 0
548                         printk("clone: child stack:\n");
549                         show_stackframe(childstack);
550 #endif
551
552                         childregs->u_regs[UREG_FP] = (unsigned long)childstack;
553                 }
554         }
555
556 #ifdef CONFIG_SMP
557         /* FPU must be disabled on SMP. */
558         childregs->psr &= ~PSR_EF;
559 #endif
560
561         /* Set the return value for the child. */
562         childregs->u_regs[UREG_I0] = current->pid;
563         childregs->u_regs[UREG_I1] = 1;
564
565         /* Set the return value for the parent. */
566         regs->u_regs[UREG_I1] = 0;
567
568         if (clone_flags & CLONE_SETTLS)
569                 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
570
571         return 0;
572 }
573
574 /*
575  * fill in the user structure for a core dump..
576  */
577 void dump_thread(struct pt_regs * regs, struct user * dump)
578 {
579         unsigned long first_stack_page;
580
581         dump->magic = SUNOS_CORE_MAGIC;
582         dump->len = sizeof(struct user);
583         dump->regs.psr = regs->psr;
584         dump->regs.pc = regs->pc;
585         dump->regs.npc = regs->npc;
586         dump->regs.y = regs->y;
587         /* fuck me plenty */
588         memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
589         dump->uexec = current->thread.core_exec;
590         dump->u_tsize = (((unsigned long) current->mm->end_code) -
591                 ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
592         dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
593         dump->u_dsize -= dump->u_tsize;
594         dump->u_dsize &= ~(PAGE_SIZE - 1);
595         first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
596         dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
597         memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
598         dump->fpu.fpstatus.fsr = current->thread.fsr;
599         dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
600         dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth;
601         memcpy(&dump->fpu.fpstatus.fpq[0], &current->thread.fpqueue[0],
602                ((sizeof(unsigned long) * 2) * 16));
603         dump->sigcode = 0;
604 }
605
606 /*
607  * fill in the fpu structure for a core dump.
608  */
609 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
610 {
611         if (used_math()) {
612                 memset(fpregs, 0, sizeof(*fpregs));
613                 fpregs->pr_q_entrysize = 8;
614                 return 1;
615         }
616 #ifdef CONFIG_SMP
617         if (current_thread_info()->flags & _TIF_USEDFPU) {
618                 put_psr(get_psr() | PSR_EF);
619                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
620                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
621                 if (regs != NULL) {
622                         regs->psr &= ~(PSR_EF);
623                         current_thread_info()->flags &= ~(_TIF_USEDFPU);
624                 }
625         }
626 #else
627         if (current == last_task_used_math) {
628                 put_psr(get_psr() | PSR_EF);
629                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
630                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
631                 if (regs != NULL) {
632                         regs->psr &= ~(PSR_EF);
633                         last_task_used_math = NULL;
634                 }
635         }
636 #endif
637         memcpy(&fpregs->pr_fr.pr_regs[0],
638                &current->thread.float_regs[0],
639                (sizeof(unsigned long) * 32));
640         fpregs->pr_fsr = current->thread.fsr;
641         fpregs->pr_qcnt = current->thread.fpqdepth;
642         fpregs->pr_q_entrysize = 8;
643         fpregs->pr_en = 1;
644         if(fpregs->pr_qcnt != 0) {
645                 memcpy(&fpregs->pr_q[0],
646                        &current->thread.fpqueue[0],
647                        sizeof(struct fpq) * fpregs->pr_qcnt);
648         }
649         /* Zero out the rest. */
650         memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
651                sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
652         return 1;
653 }
654
655 /*
656  * sparc_execve() executes a new program after the asm stub has set
657  * things up for us.  This should basically do what I want it to.
658  */
659 asmlinkage int sparc_execve(struct pt_regs *regs)
660 {
661         int error, base = 0;
662         char *filename;
663
664         /* Check for indirect call. */
665         if(regs->u_regs[UREG_G1] == 0)
666                 base = 1;
667
668         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
669         error = PTR_ERR(filename);
670         if(IS_ERR(filename))
671                 goto out;
672         error = do_execve(filename,
673                           (char __user * __user *)regs->u_regs[base + UREG_I1],
674                           (char __user * __user *)regs->u_regs[base + UREG_I2],
675                           regs);
676         putname(filename);
677         if (error == 0) {
678                 task_lock(current);
679                 current->ptrace &= ~PT_DTRACE;
680                 task_unlock(current);
681         }
682 out:
683         return error;
684 }
685
686 /*
687  * This is the mechanism for creating a new kernel thread.
688  *
689  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
690  * who haven't done an "execve()") should use this: it will work within
691  * a system call from a "real" process, but the process memory space will
692  * not be free'd until both the parent and the child have exited.
693  */
694 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
695 {
696         long retval;
697
698         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Set aside fn ptr... */
699                              "mov %5, %%g3\n\t"    /* and arg. */
700                              "mov %1, %%g1\n\t"
701                              "mov %2, %%o0\n\t"    /* Clone flags. */
702                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
703                              "t 0x10\n\t"          /* Linux/Sparc clone(). */
704                              "cmp %%o1, 0\n\t"
705                              "be 1f\n\t"           /* The parent, just return. */
706                              " nop\n\t"            /* Delay slot. */
707                              "jmpl %%g2, %%o7\n\t" /* Call the function. */
708                              " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
709                              "mov %3, %%g1\n\t"
710                              "t 0x10\n\t"          /* Linux/Sparc exit(). */
711                              /* Notreached by child. */
712                              "1: mov %%o0, %0\n\t" :
713                              "=r" (retval) :
714                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
715                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
716                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
717         return retval;
718 }
719
720 unsigned long get_wchan(struct task_struct *task)
721 {
722         unsigned long pc, fp, bias = 0;
723         unsigned long task_base = (unsigned long) task;
724         unsigned long ret = 0;
725         struct reg_window *rw;
726         int count = 0;
727
728         if (!task || task == current ||
729             task->state == TASK_RUNNING)
730                 goto out;
731
732         fp = task->thread_info->ksp + bias;
733         do {
734                 /* Bogus frame pointer? */
735                 if (fp < (task_base + sizeof(struct thread_info)) ||
736                     fp >= (task_base + (2 * PAGE_SIZE)))
737                         break;
738                 rw = (struct reg_window *) fp;
739                 pc = rw->ins[7];
740                 if (!in_sched_functions(pc)) {
741                         ret = pc;
742                         goto out;
743                 }
744                 fp = rw->ins[6] + bias;
745         } while (++count < 16);
746
747 out:
748         return ret;
749 }
750