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