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