8c37f8f5adb7f0ef2d49f5910c984f22307b2951
[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/smp.h>
26 #include <linux/reboot.h>
27 #include <linux/delay.h>
28 #include <linux/pm.h>
29 #include <linux/init.h>
30
31 #include <asm/auxio.h>
32 #include <asm/oplib.h>
33 #include <asm/uaccess.h>
34 #include <asm/system.h>
35 #include <asm/page.h>
36 #include <asm/pgalloc.h>
37 #include <asm/pgtable.h>
38 #include <asm/delay.h>
39 #include <asm/processor.h>
40 #include <asm/psr.h>
41 #include <asm/elf.h>
42 #include <asm/unistd.h>
43
44 /* 
45  * Power management idle function 
46  * Set in pm platform drivers (apc.c and pmc.c)
47  */
48 void (*pm_idle)(void);
49
50 /* 
51  * Power-off handler instantiation for pm.h compliance
52  * This is done via auxio, but could be used as a fallback
53  * handler when auxio is not present-- unused for now...
54  */
55 void (*pm_power_off)(void) = machine_power_off;
56 EXPORT_SYMBOL(pm_power_off);
57
58 /*
59  * sysctl - toggle power-off restriction for serial console 
60  * systems in machine_power_off()
61  */
62 int scons_pwroff = 1;
63
64 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
65
66 struct task_struct *last_task_used_math = NULL;
67 struct thread_info *current_set[NR_CPUS];
68
69 #ifndef CONFIG_SMP
70
71 #define SUN4C_FAULT_HIGH 100
72
73 /*
74  * the idle loop on a Sparc... ;)
75  */
76 void cpu_idle(void)
77 {
78         /* endless idle loop with no priority at all */
79         for (;;) {
80                 if (ARCH_SUN4C_SUN4) {
81                         static int count = HZ;
82                         static unsigned long last_jiffies;
83                         static unsigned long last_faults;
84                         static unsigned long fps;
85                         unsigned long now;
86                         unsigned long faults;
87
88                         extern unsigned long sun4c_kernel_faults;
89                         extern void sun4c_grow_kernel_ring(void);
90
91                         local_irq_disable();
92                         now = jiffies;
93                         count -= (now - last_jiffies);
94                         last_jiffies = now;
95                         if (count < 0) {
96                                 count += HZ;
97                                 faults = sun4c_kernel_faults;
98                                 fps = (fps + (faults - last_faults)) >> 1;
99                                 last_faults = faults;
100 #if 0
101                                 printk("kernel faults / second = %ld\n", fps);
102 #endif
103                                 if (fps >= SUN4C_FAULT_HIGH) {
104                                         sun4c_grow_kernel_ring();
105                                 }
106                         }
107                         local_irq_enable();
108                 }
109
110                 if (pm_idle) {
111                         while (!need_resched())
112                                 (*pm_idle)();
113                 } else {
114                         while (!need_resched())
115                                 cpu_relax();
116                 }
117                 preempt_enable_no_resched();
118                 schedule();
119                 preempt_disable();
120                 check_pgt_cache();
121         }
122 }
123
124 #else
125
126 /* This is being executed in task 0 'user space'. */
127 void cpu_idle(void)
128 {
129         set_thread_flag(TIF_POLLING_NRFLAG);
130         /* endless idle loop with no priority at all */
131         while(1) {
132                 while (!need_resched())
133                         cpu_relax();
134                 preempt_enable_no_resched();
135                 schedule();
136                 preempt_disable();
137                 check_pgt_cache();
138         }
139 }
140
141 #endif
142
143 extern char reboot_command [];
144
145 extern void (*prom_palette)(int);
146
147 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
148 void machine_halt(void)
149 {
150         local_irq_enable();
151         mdelay(8);
152         local_irq_disable();
153         if (!serial_console && prom_palette)
154                 prom_palette (1);
155         prom_halt();
156         panic("Halt failed!");
157 }
158
159 void machine_restart(char * cmd)
160 {
161         char *p;
162         
163         local_irq_enable();
164         mdelay(8);
165         local_irq_disable();
166
167         p = strchr (reboot_command, '\n');
168         if (p) *p = 0;
169         if (!serial_console && prom_palette)
170                 prom_palette (1);
171         if (cmd)
172                 prom_reboot(cmd);
173         if (*reboot_command)
174                 prom_reboot(reboot_command);
175         prom_feval ("reset");
176         panic("Reboot failed!");
177 }
178
179 void machine_power_off(void)
180 {
181 #ifdef CONFIG_SUN_AUXIO
182         if (auxio_power_register && (!serial_console || scons_pwroff))
183                 *auxio_power_register |= AUXIO_POWER_OFF;
184 #endif
185         machine_halt();
186 }
187
188 static DEFINE_SPINLOCK(sparc_backtrace_lock);
189
190 void __show_backtrace(unsigned long fp)
191 {
192         struct reg_window *rw;
193         unsigned long flags;
194         int cpu = smp_processor_id();
195
196         spin_lock_irqsave(&sparc_backtrace_lock, flags);
197
198         rw = (struct reg_window *)fp;
199         while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
200             !(((unsigned long) rw) & 0x7)) {
201                 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
202                        "FP[%08lx] CALLER[%08lx]: ", cpu,
203                        rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
204                        rw->ins[4], rw->ins[5],
205                        rw->ins[6],
206                        rw->ins[7]);
207                 print_symbol("%s\n", rw->ins[7]);
208                 rw = (struct reg_window *) rw->ins[6];
209         }
210         spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
211 }
212
213 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
214 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
215 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
216
217 void show_backtrace(void)
218 {
219         unsigned long fp;
220
221         __SAVE; __SAVE; __SAVE; __SAVE;
222         __SAVE; __SAVE; __SAVE; __SAVE;
223         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
224         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
225
226         __GET_FP(fp);
227
228         __show_backtrace(fp);
229 }
230
231 #ifdef CONFIG_SMP
232 void smp_show_backtrace_all_cpus(void)
233 {
234         xc0((smpfunc_t) show_backtrace);
235         show_backtrace();
236 }
237 #endif
238
239 #if 0
240 void show_stackframe(struct sparc_stackf *sf)
241 {
242         unsigned long size;
243         unsigned long *stk;
244         int i;
245
246         printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
247                "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
248                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
249                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
250         printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
251                "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
252                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
253                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
254         printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
255                "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
256                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
257                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
258                sf->xxargs[0]);
259         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
260         size -= STACKFRAME_SZ;
261         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
262         i = 0;
263         do {
264                 printk("s%d: %08lx\n", i++, *stk++);
265         } while ((size -= sizeof(unsigned long)));
266 }
267 #endif
268
269 void show_regs(struct pt_regs *r)
270 {
271         struct reg_window *rw = (struct reg_window *) r->u_regs[14];
272
273         printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx    %s\n",
274                r->psr, r->pc, r->npc, r->y, print_tainted());
275         print_symbol("PC: <%s>\n", r->pc);
276         printk("%%G: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
277                r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
278                r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
279         printk("%%O: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
280                r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
281                r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
282         print_symbol("RPC: <%s>\n", r->u_regs[15]);
283
284         printk("%%L: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
285                rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
286                rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
287         printk("%%I: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
288                rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
289                rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
290 }
291
292 /*
293  * The show_stack is an external API which we do not use ourselves.
294  * The oops is printed in die_if_kernel.
295  */
296 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
297 {
298         unsigned long pc, fp;
299         unsigned long task_base;
300         struct reg_window *rw;
301         int count = 0;
302
303         if (tsk != NULL)
304                 task_base = (unsigned long) task_stack_page(tsk);
305         else
306                 task_base = (unsigned long) current_thread_info();
307
308         fp = (unsigned long) _ksp;
309         do {
310                 /* Bogus frame pointer? */
311                 if (fp < (task_base + sizeof(struct thread_info)) ||
312                     fp >= (task_base + (PAGE_SIZE << 1)))
313                         break;
314                 rw = (struct reg_window *) fp;
315                 pc = rw->ins[7];
316                 printk("[%08lx : ", pc);
317                 print_symbol("%s ] ", pc);
318                 fp = rw->ins[6];
319         } while (++count < 16);
320         printk("\n");
321 }
322
323 void dump_stack(void)
324 {
325         unsigned long *ksp;
326
327         __asm__ __volatile__("mov       %%fp, %0"
328                              : "=r" (ksp));
329         show_stack(current, ksp);
330 }
331
332 EXPORT_SYMBOL(dump_stack);
333
334 /*
335  * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
336  */
337 unsigned long thread_saved_pc(struct task_struct *tsk)
338 {
339         return task_thread_info(tsk)->kpc;
340 }
341
342 /*
343  * Free current thread data structures etc..
344  */
345 void exit_thread(void)
346 {
347 #ifndef CONFIG_SMP
348         if(last_task_used_math == current) {
349 #else
350         if (test_thread_flag(TIF_USEDFPU)) {
351 #endif
352                 /* Keep process from leaving FPU in a bogon state. */
353                 put_psr(get_psr() | PSR_EF);
354                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
355                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
356 #ifndef CONFIG_SMP
357                 last_task_used_math = NULL;
358 #else
359                 clear_thread_flag(TIF_USEDFPU);
360 #endif
361         }
362 }
363
364 void flush_thread(void)
365 {
366         current_thread_info()->w_saved = 0;
367
368         /* No new signal delivery by default */
369         current->thread.new_signal = 0;
370 #ifndef CONFIG_SMP
371         if(last_task_used_math == current) {
372 #else
373         if (test_thread_flag(TIF_USEDFPU)) {
374 #endif
375                 /* Clean the fpu. */
376                 put_psr(get_psr() | PSR_EF);
377                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
378                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
379 #ifndef CONFIG_SMP
380                 last_task_used_math = NULL;
381 #else
382                 clear_thread_flag(TIF_USEDFPU);
383 #endif
384         }
385
386         /* Now, this task is no longer a kernel thread. */
387         current->thread.current_ds = USER_DS;
388         if (current->thread.flags & SPARC_FLAG_KTHREAD) {
389                 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
390
391                 /* We must fixup kregs as well. */
392                 /* XXX This was not fixed for ti for a while, worked. Unused? */
393                 current->thread.kregs = (struct pt_regs *)
394                     (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
395         }
396 }
397
398 static __inline__ struct sparc_stackf __user *
399 clone_stackframe(struct sparc_stackf __user *dst,
400                  struct sparc_stackf __user *src)
401 {
402         unsigned long size, fp;
403         struct sparc_stackf *tmp;
404         struct sparc_stackf __user *sp;
405
406         if (get_user(tmp, &src->fp))
407                 return NULL;
408
409         fp = (unsigned long) tmp;
410         size = (fp - ((unsigned long) src));
411         fp = (unsigned long) dst;
412         sp = (struct sparc_stackf __user *)(fp - size); 
413
414         /* do_fork() grabs the parent semaphore, we must release it
415          * temporarily so we can build the child clone stack frame
416          * without deadlocking.
417          */
418         if (__copy_user(sp, src, size))
419                 sp = NULL;
420         else if (put_user(fp, &sp->fp))
421                 sp = NULL;
422
423         return sp;
424 }
425
426 asmlinkage int sparc_do_fork(unsigned long clone_flags,
427                              unsigned long stack_start,
428                              struct pt_regs *regs,
429                              unsigned long stack_size)
430 {
431         unsigned long parent_tid_ptr, child_tid_ptr;
432
433         parent_tid_ptr = regs->u_regs[UREG_I2];
434         child_tid_ptr = regs->u_regs[UREG_I4];
435
436         return do_fork(clone_flags, stack_start,
437                        regs, stack_size,
438                        (int __user *) parent_tid_ptr,
439                        (int __user *) child_tid_ptr);
440 }
441
442 /* Copy a Sparc thread.  The fork() return value conventions
443  * under SunOS are nothing short of bletcherous:
444  * Parent -->  %o0 == childs  pid, %o1 == 0
445  * Child  -->  %o0 == parents pid, %o1 == 1
446  *
447  * NOTE: We have a separate fork kpsr/kwim because
448  *       the parent could change these values between
449  *       sys_fork invocation and when we reach here
450  *       if the parent should sleep while trying to
451  *       allocate the task_struct and kernel stack in
452  *       do_fork().
453  * XXX See comment above sys_vfork in sparc64. todo.
454  */
455 extern void ret_from_fork(void);
456
457 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
458                 unsigned long unused,
459                 struct task_struct *p, struct pt_regs *regs)
460 {
461         struct thread_info *ti = task_thread_info(p);
462         struct pt_regs *childregs;
463         char *new_stack;
464
465 #ifndef CONFIG_SMP
466         if(last_task_used_math == current) {
467 #else
468         if (test_thread_flag(TIF_USEDFPU)) {
469 #endif
470                 put_psr(get_psr() | PSR_EF);
471                 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
472                        &p->thread.fpqueue[0], &p->thread.fpqdepth);
473 #ifdef CONFIG_SMP
474                 clear_thread_flag(TIF_USEDFPU);
475 #endif
476         }
477
478         /*
479          *  p->thread_info         new_stack   childregs
480          *  !                      !           !             {if(PSR_PS) }
481          *  V                      V (stk.fr.) V  (pt_regs)  { (stk.fr.) }
482          *  +----- - - - - - ------+===========+============={+==========}+
483          */
484         new_stack = task_stack_page(p) + THREAD_SIZE;
485         if (regs->psr & PSR_PS)
486                 new_stack -= STACKFRAME_SZ;
487         new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
488         memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
489         childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
490
491         /*
492          * A new process must start with interrupts closed in 2.5,
493          * because this is how Mingo's scheduler works (see schedule_tail
494          * and finish_arch_switch). If we do not do it, a timer interrupt hits
495          * before we unlock, attempts to re-take the rq->lock, and then we die.
496          * Thus, kpsr|=PSR_PIL.
497          */
498         ti->ksp = (unsigned long) new_stack;
499         ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
500         ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
501         ti->kwim = current->thread.fork_kwim;
502
503         if(regs->psr & PSR_PS) {
504                 extern struct pt_regs fake_swapper_regs;
505
506                 p->thread.kregs = &fake_swapper_regs;
507                 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
508                 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
509                 p->thread.flags |= SPARC_FLAG_KTHREAD;
510                 p->thread.current_ds = KERNEL_DS;
511                 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
512                 childregs->u_regs[UREG_G6] = (unsigned long) ti;
513         } else {
514                 p->thread.kregs = childregs;
515                 childregs->u_regs[UREG_FP] = sp;
516                 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
517                 p->thread.current_ds = USER_DS;
518
519                 if (sp != regs->u_regs[UREG_FP]) {
520                         struct sparc_stackf __user *childstack;
521                         struct sparc_stackf __user *parentstack;
522
523                         /*
524                          * This is a clone() call with supplied user stack.
525                          * Set some valid stack frames to give to the child.
526                          */
527                         childstack = (struct sparc_stackf __user *)
528                                 (sp & ~0x7UL);
529                         parentstack = (struct sparc_stackf __user *)
530                                 regs->u_regs[UREG_FP];
531
532 #if 0
533                         printk("clone: parent stack:\n");
534                         show_stackframe(parentstack);
535 #endif
536
537                         childstack = clone_stackframe(childstack, parentstack);
538                         if (!childstack)
539                                 return -EFAULT;
540
541 #if 0
542                         printk("clone: child stack:\n");
543                         show_stackframe(childstack);
544 #endif
545
546                         childregs->u_regs[UREG_FP] = (unsigned long)childstack;
547                 }
548         }
549
550 #ifdef CONFIG_SMP
551         /* FPU must be disabled on SMP. */
552         childregs->psr &= ~PSR_EF;
553 #endif
554
555         /* Set the return value for the child. */
556         childregs->u_regs[UREG_I0] = current->pid;
557         childregs->u_regs[UREG_I1] = 1;
558
559         /* Set the return value for the parent. */
560         regs->u_regs[UREG_I1] = 0;
561
562         if (clone_flags & CLONE_SETTLS)
563                 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
564
565         return 0;
566 }
567
568 /*
569  * fill in the user structure for a core dump..
570  */
571 void dump_thread(struct pt_regs * regs, struct user * dump)
572 {
573         unsigned long first_stack_page;
574
575         dump->magic = SUNOS_CORE_MAGIC;
576         dump->len = sizeof(struct user);
577         dump->regs.psr = regs->psr;
578         dump->regs.pc = regs->pc;
579         dump->regs.npc = regs->npc;
580         dump->regs.y = regs->y;
581         /* fuck me plenty */
582         memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
583         dump->uexec = current->thread.core_exec;
584         dump->u_tsize = (((unsigned long) current->mm->end_code) -
585                 ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
586         dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
587         dump->u_dsize -= dump->u_tsize;
588         dump->u_dsize &= ~(PAGE_SIZE - 1);
589         first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
590         dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
591         memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
592         dump->fpu.fpstatus.fsr = current->thread.fsr;
593         dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
594         dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth;
595         memcpy(&dump->fpu.fpstatus.fpq[0], &current->thread.fpqueue[0],
596                ((sizeof(unsigned long) * 2) * 16));
597         dump->sigcode = 0;
598 }
599
600 /*
601  * fill in the fpu structure for a core dump.
602  */
603 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
604 {
605         if (used_math()) {
606                 memset(fpregs, 0, sizeof(*fpregs));
607                 fpregs->pr_q_entrysize = 8;
608                 return 1;
609         }
610 #ifdef CONFIG_SMP
611         if (test_thread_flag(TIF_USEDFPU)) {
612                 put_psr(get_psr() | PSR_EF);
613                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
614                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
615                 if (regs != NULL) {
616                         regs->psr &= ~(PSR_EF);
617                         clear_thread_flag(TIF_USEDFPU);
618                 }
619         }
620 #else
621         if (current == last_task_used_math) {
622                 put_psr(get_psr() | PSR_EF);
623                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
624                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
625                 if (regs != NULL) {
626                         regs->psr &= ~(PSR_EF);
627                         last_task_used_math = NULL;
628                 }
629         }
630 #endif
631         memcpy(&fpregs->pr_fr.pr_regs[0],
632                &current->thread.float_regs[0],
633                (sizeof(unsigned long) * 32));
634         fpregs->pr_fsr = current->thread.fsr;
635         fpregs->pr_qcnt = current->thread.fpqdepth;
636         fpregs->pr_q_entrysize = 8;
637         fpregs->pr_en = 1;
638         if(fpregs->pr_qcnt != 0) {
639                 memcpy(&fpregs->pr_q[0],
640                        &current->thread.fpqueue[0],
641                        sizeof(struct fpq) * fpregs->pr_qcnt);
642         }
643         /* Zero out the rest. */
644         memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
645                sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
646         return 1;
647 }
648
649 /*
650  * sparc_execve() executes a new program after the asm stub has set
651  * things up for us.  This should basically do what I want it to.
652  */
653 asmlinkage int sparc_execve(struct pt_regs *regs)
654 {
655         int error, base = 0;
656         char *filename;
657
658         /* Check for indirect call. */
659         if(regs->u_regs[UREG_G1] == 0)
660                 base = 1;
661
662         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
663         error = PTR_ERR(filename);
664         if(IS_ERR(filename))
665                 goto out;
666         error = do_execve(filename,
667                           (char __user * __user *)regs->u_regs[base + UREG_I1],
668                           (char __user * __user *)regs->u_regs[base + UREG_I2],
669                           regs);
670         putname(filename);
671         if (error == 0) {
672                 task_lock(current);
673                 current->ptrace &= ~PT_DTRACE;
674                 task_unlock(current);
675         }
676 out:
677         return error;
678 }
679
680 /*
681  * This is the mechanism for creating a new kernel thread.
682  *
683  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
684  * who haven't done an "execve()") should use this: it will work within
685  * a system call from a "real" process, but the process memory space will
686  * not be freed until both the parent and the child have exited.
687  */
688 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
689 {
690         long retval;
691
692         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Set aside fn ptr... */
693                              "mov %5, %%g3\n\t"    /* and arg. */
694                              "mov %1, %%g1\n\t"
695                              "mov %2, %%o0\n\t"    /* Clone flags. */
696                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
697                              "t 0x10\n\t"          /* Linux/Sparc clone(). */
698                              "cmp %%o1, 0\n\t"
699                              "be 1f\n\t"           /* The parent, just return. */
700                              " nop\n\t"            /* Delay slot. */
701                              "jmpl %%g2, %%o7\n\t" /* Call the function. */
702                              " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
703                              "mov %3, %%g1\n\t"
704                              "t 0x10\n\t"          /* Linux/Sparc exit(). */
705                              /* Notreached by child. */
706                              "1: mov %%o0, %0\n\t" :
707                              "=r" (retval) :
708                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
709                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
710                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
711         return retval;
712 }
713
714 unsigned long get_wchan(struct task_struct *task)
715 {
716         unsigned long pc, fp, bias = 0;
717         unsigned long task_base = (unsigned long) task;
718         unsigned long ret = 0;
719         struct reg_window *rw;
720         int count = 0;
721
722         if (!task || task == current ||
723             task->state == TASK_RUNNING)
724                 goto out;
725
726         fp = task_thread_info(task)->ksp + bias;
727         do {
728                 /* Bogus frame pointer? */
729                 if (fp < (task_base + sizeof(struct thread_info)) ||
730                     fp >= (task_base + (2 * PAGE_SIZE)))
731                         break;
732                 rw = (struct reg_window *) fp;
733                 pc = rw->ins[7];
734                 if (!in_sched_functions(pc)) {
735                         ret = pc;
736                         goto out;
737                 }
738                 fp = rw->ins[6] + bias;
739         } while (++count < 16);
740
741 out:
742         return ret;
743 }
744