2c216ffeea90b61535eae1cd37d07b7f9acdb479
[linux-3.10.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 EXPORT_SYMBOL(machine_halt);
162
163 void machine_restart(char * cmd)
164 {
165         char *p;
166         
167         local_irq_enable();
168         mdelay(8);
169         local_irq_disable();
170
171         p = strchr (reboot_command, '\n');
172         if (p) *p = 0;
173         if (!serial_console && prom_palette)
174                 prom_palette (1);
175         if (cmd)
176                 prom_reboot(cmd);
177         if (*reboot_command)
178                 prom_reboot(reboot_command);
179         prom_feval ("reset");
180         panic("Reboot failed!");
181 }
182
183 EXPORT_SYMBOL(machine_restart);
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 EXPORT_SYMBOL(machine_power_off);
195
196 static DEFINE_SPINLOCK(sparc_backtrace_lock);
197
198 void __show_backtrace(unsigned long fp)
199 {
200         struct reg_window *rw;
201         unsigned long flags;
202         int cpu = smp_processor_id();
203
204         spin_lock_irqsave(&sparc_backtrace_lock, flags);
205
206         rw = (struct reg_window *)fp;
207         while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
208             !(((unsigned long) rw) & 0x7)) {
209                 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
210                        "FP[%08lx] CALLER[%08lx]: ", cpu,
211                        rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
212                        rw->ins[4], rw->ins[5],
213                        rw->ins[6],
214                        rw->ins[7]);
215                 print_symbol("%s\n", rw->ins[7]);
216                 rw = (struct reg_window *) rw->ins[6];
217         }
218         spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
219 }
220
221 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
222 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
223 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
224
225 void show_backtrace(void)
226 {
227         unsigned long fp;
228
229         __SAVE; __SAVE; __SAVE; __SAVE;
230         __SAVE; __SAVE; __SAVE; __SAVE;
231         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
232         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
233
234         __GET_FP(fp);
235
236         __show_backtrace(fp);
237 }
238
239 #ifdef CONFIG_SMP
240 void smp_show_backtrace_all_cpus(void)
241 {
242         xc0((smpfunc_t) show_backtrace);
243         show_backtrace();
244 }
245 #endif
246
247 #if 0
248 void show_stackframe(struct sparc_stackf *sf)
249 {
250         unsigned long size;
251         unsigned long *stk;
252         int i;
253
254         printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
255                "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
256                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
257                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
258         printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
259                "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
260                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
261                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
262         printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
263                "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
264                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
265                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
266                sf->xxargs[0]);
267         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
268         size -= STACKFRAME_SZ;
269         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
270         i = 0;
271         do {
272                 printk("s%d: %08lx\n", i++, *stk++);
273         } while ((size -= sizeof(unsigned long)));
274 }
275 #endif
276
277 void show_regs(struct pt_regs *r)
278 {
279         struct reg_window *rw = (struct reg_window *) r->u_regs[14];
280
281         printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx    %s\n",
282                r->psr, r->pc, r->npc, r->y, print_tainted());
283         print_symbol("PC: <%s>\n", r->pc);
284         printk("%%G: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
285                r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
286                r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
287         printk("%%O: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
288                r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
289                r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
290         print_symbol("RPC: <%s>\n", r->u_regs[15]);
291
292         printk("%%L: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
293                rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
294                rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
295         printk("%%I: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
296                rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
297                rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
298 }
299
300 /*
301  * The show_stack is an external API which we do not use ourselves.
302  * The oops is printed in die_if_kernel.
303  */
304 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
305 {
306         unsigned long pc, fp;
307         unsigned long task_base;
308         struct reg_window *rw;
309         int count = 0;
310
311         if (tsk != NULL)
312                 task_base = (unsigned long) tsk->thread_info;
313         else
314                 task_base = (unsigned long) current_thread_info();
315
316         fp = (unsigned long) _ksp;
317         do {
318                 /* Bogus frame pointer? */
319                 if (fp < (task_base + sizeof(struct thread_info)) ||
320                     fp >= (task_base + (PAGE_SIZE << 1)))
321                         break;
322                 rw = (struct reg_window *) fp;
323                 pc = rw->ins[7];
324                 printk("[%08lx : ", pc);
325                 print_symbol("%s ] ", pc);
326                 fp = rw->ins[6];
327         } while (++count < 16);
328         printk("\n");
329 }
330
331 void dump_stack(void)
332 {
333         unsigned long *ksp;
334
335         __asm__ __volatile__("mov       %%fp, %0"
336                              : "=r" (ksp));
337         show_stack(current, ksp);
338 }
339
340 EXPORT_SYMBOL(dump_stack);
341
342 /*
343  * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
344  */
345 unsigned long thread_saved_pc(struct task_struct *tsk)
346 {
347         return tsk->thread_info->kpc;
348 }
349
350 /*
351  * Free current thread data structures etc..
352  */
353 void exit_thread(void)
354 {
355 #ifndef CONFIG_SMP
356         if(last_task_used_math == current) {
357 #else
358         if(current_thread_info()->flags & _TIF_USEDFPU) {
359 #endif
360                 /* Keep process from leaving FPU in a bogon state. */
361                 put_psr(get_psr() | PSR_EF);
362                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
363                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
364 #ifndef CONFIG_SMP
365                 last_task_used_math = NULL;
366 #else
367                 current_thread_info()->flags &= ~_TIF_USEDFPU;
368 #endif
369         }
370 }
371
372 void flush_thread(void)
373 {
374         current_thread_info()->w_saved = 0;
375
376         /* No new signal delivery by default */
377         current->thread.new_signal = 0;
378 #ifndef CONFIG_SMP
379         if(last_task_used_math == current) {
380 #else
381         if(current_thread_info()->flags & _TIF_USEDFPU) {
382 #endif
383                 /* Clean the fpu. */
384                 put_psr(get_psr() | PSR_EF);
385                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
386                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
387 #ifndef CONFIG_SMP
388                 last_task_used_math = NULL;
389 #else
390                 current_thread_info()->flags &= ~_TIF_USEDFPU;
391 #endif
392         }
393
394         /* Now, this task is no longer a kernel thread. */
395         current->thread.current_ds = USER_DS;
396         if (current->thread.flags & SPARC_FLAG_KTHREAD) {
397                 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
398
399                 /* We must fixup kregs as well. */
400                 /* XXX This was not fixed for ti for a while, worked. Unused? */
401                 current->thread.kregs = (struct pt_regs *)
402                     ((char *)current->thread_info + (THREAD_SIZE - TRACEREG_SZ));
403         }
404 }
405
406 static __inline__ struct sparc_stackf __user *
407 clone_stackframe(struct sparc_stackf __user *dst,
408                  struct sparc_stackf __user *src)
409 {
410         unsigned long size, fp;
411         struct sparc_stackf *tmp;
412         struct sparc_stackf __user *sp;
413
414         if (get_user(tmp, &src->fp))
415                 return NULL;
416
417         fp = (unsigned long) tmp;
418         size = (fp - ((unsigned long) src));
419         fp = (unsigned long) dst;
420         sp = (struct sparc_stackf __user *)(fp - size); 
421
422         /* do_fork() grabs the parent semaphore, we must release it
423          * temporarily so we can build the child clone stack frame
424          * without deadlocking.
425          */
426         if (__copy_user(sp, src, size))
427                 sp = NULL;
428         else if (put_user(fp, &sp->fp))
429                 sp = NULL;
430
431         return sp;
432 }
433
434 asmlinkage int sparc_do_fork(unsigned long clone_flags,
435                              unsigned long stack_start,
436                              struct pt_regs *regs,
437                              unsigned long stack_size)
438 {
439         unsigned long parent_tid_ptr, child_tid_ptr;
440
441         parent_tid_ptr = regs->u_regs[UREG_I2];
442         child_tid_ptr = regs->u_regs[UREG_I4];
443
444         return do_fork(clone_flags, stack_start,
445                        regs, stack_size,
446                        (int __user *) parent_tid_ptr,
447                        (int __user *) child_tid_ptr);
448 }
449
450 /* Copy a Sparc thread.  The fork() return value conventions
451  * under SunOS are nothing short of bletcherous:
452  * Parent -->  %o0 == childs  pid, %o1 == 0
453  * Child  -->  %o0 == parents pid, %o1 == 1
454  *
455  * NOTE: We have a separate fork kpsr/kwim because
456  *       the parent could change these values between
457  *       sys_fork invocation and when we reach here
458  *       if the parent should sleep while trying to
459  *       allocate the task_struct and kernel stack in
460  *       do_fork().
461  * XXX See comment above sys_vfork in sparc64. todo.
462  */
463 extern void ret_from_fork(void);
464
465 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
466                 unsigned long unused,
467                 struct task_struct *p, struct pt_regs *regs)
468 {
469         struct thread_info *ti = p->thread_info;
470         struct pt_regs *childregs;
471         char *new_stack;
472
473 #ifndef CONFIG_SMP
474         if(last_task_used_math == current) {
475 #else
476         if(current_thread_info()->flags & _TIF_USEDFPU) {
477 #endif
478                 put_psr(get_psr() | PSR_EF);
479                 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
480                        &p->thread.fpqueue[0], &p->thread.fpqdepth);
481 #ifdef CONFIG_SMP
482                 current_thread_info()->flags &= ~_TIF_USEDFPU;
483 #endif
484         }
485
486         /*
487          *  p->thread_info         new_stack   childregs
488          *  !                      !           !             {if(PSR_PS) }
489          *  V                      V (stk.fr.) V  (pt_regs)  { (stk.fr.) }
490          *  +----- - - - - - ------+===========+============={+==========}+
491          */
492         new_stack = (char*)ti + THREAD_SIZE;
493         if (regs->psr & PSR_PS)
494                 new_stack -= STACKFRAME_SZ;
495         new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
496         memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
497         childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
498
499         /*
500          * A new process must start with interrupts closed in 2.5,
501          * because this is how Mingo's scheduler works (see schedule_tail
502          * and finish_arch_switch). If we do not do it, a timer interrupt hits
503          * before we unlock, attempts to re-take the rq->lock, and then we die.
504          * Thus, kpsr|=PSR_PIL.
505          */
506         ti->ksp = (unsigned long) new_stack;
507         ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
508         ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
509         ti->kwim = current->thread.fork_kwim;
510
511         if(regs->psr & PSR_PS) {
512                 extern struct pt_regs fake_swapper_regs;
513
514                 p->thread.kregs = &fake_swapper_regs;
515                 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
516                 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
517                 p->thread.flags |= SPARC_FLAG_KTHREAD;
518                 p->thread.current_ds = KERNEL_DS;
519                 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
520                 childregs->u_regs[UREG_G6] = (unsigned long) ti;
521         } else {
522                 p->thread.kregs = childregs;
523                 childregs->u_regs[UREG_FP] = sp;
524                 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
525                 p->thread.current_ds = USER_DS;
526
527                 if (sp != regs->u_regs[UREG_FP]) {
528                         struct sparc_stackf __user *childstack;
529                         struct sparc_stackf __user *parentstack;
530
531                         /*
532                          * This is a clone() call with supplied user stack.
533                          * Set some valid stack frames to give to the child.
534                          */
535                         childstack = (struct sparc_stackf __user *)
536                                 (sp & ~0x7UL);
537                         parentstack = (struct sparc_stackf __user *)
538                                 regs->u_regs[UREG_FP];
539
540 #if 0
541                         printk("clone: parent stack:\n");
542                         show_stackframe(parentstack);
543 #endif
544
545                         childstack = clone_stackframe(childstack, parentstack);
546                         if (!childstack)
547                                 return -EFAULT;
548
549 #if 0
550                         printk("clone: child stack:\n");
551                         show_stackframe(childstack);
552 #endif
553
554                         childregs->u_regs[UREG_FP] = (unsigned long)childstack;
555                 }
556         }
557
558 #ifdef CONFIG_SMP
559         /* FPU must be disabled on SMP. */
560         childregs->psr &= ~PSR_EF;
561 #endif
562
563         /* Set the return value for the child. */
564         childregs->u_regs[UREG_I0] = current->pid;
565         childregs->u_regs[UREG_I1] = 1;
566
567         /* Set the return value for the parent. */
568         regs->u_regs[UREG_I1] = 0;
569
570         if (clone_flags & CLONE_SETTLS)
571                 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
572
573         return 0;
574 }
575
576 /*
577  * fill in the user structure for a core dump..
578  */
579 void dump_thread(struct pt_regs * regs, struct user * dump)
580 {
581         unsigned long first_stack_page;
582
583         dump->magic = SUNOS_CORE_MAGIC;
584         dump->len = sizeof(struct user);
585         dump->regs.psr = regs->psr;
586         dump->regs.pc = regs->pc;
587         dump->regs.npc = regs->npc;
588         dump->regs.y = regs->y;
589         /* fuck me plenty */
590         memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
591         dump->uexec = current->thread.core_exec;
592         dump->u_tsize = (((unsigned long) current->mm->end_code) -
593                 ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
594         dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
595         dump->u_dsize -= dump->u_tsize;
596         dump->u_dsize &= ~(PAGE_SIZE - 1);
597         first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
598         dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
599         memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
600         dump->fpu.fpstatus.fsr = current->thread.fsr;
601         dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
602         dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth;
603         memcpy(&dump->fpu.fpstatus.fpq[0], &current->thread.fpqueue[0],
604                ((sizeof(unsigned long) * 2) * 16));
605         dump->sigcode = 0;
606 }
607
608 /*
609  * fill in the fpu structure for a core dump.
610  */
611 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
612 {
613         if (used_math()) {
614                 memset(fpregs, 0, sizeof(*fpregs));
615                 fpregs->pr_q_entrysize = 8;
616                 return 1;
617         }
618 #ifdef CONFIG_SMP
619         if (current_thread_info()->flags & _TIF_USEDFPU) {
620                 put_psr(get_psr() | PSR_EF);
621                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
622                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
623                 if (regs != NULL) {
624                         regs->psr &= ~(PSR_EF);
625                         current_thread_info()->flags &= ~(_TIF_USEDFPU);
626                 }
627         }
628 #else
629         if (current == last_task_used_math) {
630                 put_psr(get_psr() | PSR_EF);
631                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
632                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
633                 if (regs != NULL) {
634                         regs->psr &= ~(PSR_EF);
635                         last_task_used_math = NULL;
636                 }
637         }
638 #endif
639         memcpy(&fpregs->pr_fr.pr_regs[0],
640                &current->thread.float_regs[0],
641                (sizeof(unsigned long) * 32));
642         fpregs->pr_fsr = current->thread.fsr;
643         fpregs->pr_qcnt = current->thread.fpqdepth;
644         fpregs->pr_q_entrysize = 8;
645         fpregs->pr_en = 1;
646         if(fpregs->pr_qcnt != 0) {
647                 memcpy(&fpregs->pr_q[0],
648                        &current->thread.fpqueue[0],
649                        sizeof(struct fpq) * fpregs->pr_qcnt);
650         }
651         /* Zero out the rest. */
652         memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
653                sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
654         return 1;
655 }
656
657 /*
658  * sparc_execve() executes a new program after the asm stub has set
659  * things up for us.  This should basically do what I want it to.
660  */
661 asmlinkage int sparc_execve(struct pt_regs *regs)
662 {
663         int error, base = 0;
664         char *filename;
665
666         /* Check for indirect call. */
667         if(regs->u_regs[UREG_G1] == 0)
668                 base = 1;
669
670         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
671         error = PTR_ERR(filename);
672         if(IS_ERR(filename))
673                 goto out;
674         error = do_execve(filename,
675                           (char __user * __user *)regs->u_regs[base + UREG_I1],
676                           (char __user * __user *)regs->u_regs[base + UREG_I2],
677                           regs);
678         putname(filename);
679         if (error == 0) {
680                 task_lock(current);
681                 current->ptrace &= ~PT_DTRACE;
682                 task_unlock(current);
683         }
684 out:
685         return error;
686 }
687
688 /*
689  * This is the mechanism for creating a new kernel thread.
690  *
691  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
692  * who haven't done an "execve()") should use this: it will work within
693  * a system call from a "real" process, but the process memory space will
694  * not be free'd until both the parent and the child have exited.
695  */
696 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
697 {
698         long retval;
699
700         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Set aside fn ptr... */
701                              "mov %5, %%g3\n\t"    /* and arg. */
702                              "mov %1, %%g1\n\t"
703                              "mov %2, %%o0\n\t"    /* Clone flags. */
704                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
705                              "t 0x10\n\t"          /* Linux/Sparc clone(). */
706                              "cmp %%o1, 0\n\t"
707                              "be 1f\n\t"           /* The parent, just return. */
708                              " nop\n\t"            /* Delay slot. */
709                              "jmpl %%g2, %%o7\n\t" /* Call the function. */
710                              " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
711                              "mov %3, %%g1\n\t"
712                              "t 0x10\n\t"          /* Linux/Sparc exit(). */
713                              /* Notreached by child. */
714                              "1: mov %%o0, %0\n\t" :
715                              "=r" (retval) :
716                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
717                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
718                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
719         return retval;
720 }
721
722 unsigned long get_wchan(struct task_struct *task)
723 {
724         unsigned long pc, fp, bias = 0;
725         unsigned long task_base = (unsigned long) task;
726         unsigned long ret = 0;
727         struct reg_window *rw;
728         int count = 0;
729
730         if (!task || task == current ||
731             task->state == TASK_RUNNING)
732                 goto out;
733
734         fp = task->thread_info->ksp + bias;
735         do {
736                 /* Bogus frame pointer? */
737                 if (fp < (task_base + sizeof(struct thread_info)) ||
738                     fp >= (task_base + (2 * PAGE_SIZE)))
739                         break;
740                 rw = (struct reg_window *) fp;
741                 pc = rw->ins[7];
742                 if (!in_sched_functions(pc)) {
743                         ret = pc;
744                         goto out;
745                 }
746                 fp = rw->ins[6] + bias;
747         } while (++count < 16);
748
749 out:
750         return ret;
751 }
752