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/arch/sparc/kernel/process.c

https://bitbucket.org/evzijst/gittest
C | 746 lines | 543 code | 94 blank | 109 comment | 67 complexity | fa61dd856e85a6f2ee1b3dc7762803d2 MD5 | raw file
  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 */
 50void (*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 */
 57void (*pm_power_off)(void);
 58
 59/*
 60 * sysctl - toggle power-off restriction for serial console 
 61 * systems in machine_power_off()
 62 */
 63int scons_pwroff = 1;
 64
 65extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
 66
 67struct task_struct *last_task_used_math = NULL;
 68struct thread_info *current_set[NR_CPUS];
 69
 70/*
 71 * default_idle is new in 2.5. XXX Review, currently stolen from sparc64.
 72 */
 73void 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 */
 84void cpu_idle(void)
 85{
 86	if (current->pid != 0)
 87		goto out;
 88
 89	/* endless idle loop with no priority at all */
 90	for (;;) {
 91		if (ARCH_SUN4C_SUN4) {
 92			static int count = HZ;
 93			static unsigned long last_jiffies;
 94			static unsigned long last_faults;
 95			static unsigned long fps;
 96			unsigned long now;
 97			unsigned long faults;
 98			unsigned long flags;
 99
100			extern unsigned long sun4c_kernel_faults;
101			extern void sun4c_grow_kernel_ring(void);
102
103			local_irq_save(flags);
104			now = jiffies;
105			count -= (now - last_jiffies);
106			last_jiffies = now;
107			if (count < 0) {
108				count += HZ;
109				faults = sun4c_kernel_faults;
110				fps = (fps + (faults - last_faults)) >> 1;
111				last_faults = faults;
112#if 0
113				printk("kernel faults / second = %ld\n", fps);
114#endif
115				if (fps >= SUN4C_FAULT_HIGH) {
116					sun4c_grow_kernel_ring();
117				}
118			}
119			local_irq_restore(flags);
120		}
121
122		while((!need_resched()) && pm_idle) {
123			(*pm_idle)();
124		}
125
126		schedule();
127		check_pgt_cache();
128	}
129out:
130	return;
131}
132
133#else
134
135/* This is being executed in task 0 'user space'. */
136void cpu_idle(void)
137{
138	/* endless idle loop with no priority at all */
139	while(1) {
140		if(need_resched()) {
141			schedule();
142			check_pgt_cache();
143		}
144		barrier(); /* or else gcc optimizes... */
145	}
146}
147
148#endif
149
150extern char reboot_command [];
151
152extern void (*prom_palette)(int);
153
154/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
155void machine_halt(void)
156{
157	local_irq_enable();
158	mdelay(8);
159	local_irq_disable();
160	if (!serial_console && prom_palette)
161		prom_palette (1);
162	prom_halt();
163	panic("Halt failed!");
164}
165
166EXPORT_SYMBOL(machine_halt);
167
168void machine_restart(char * cmd)
169{
170	char *p;
171	
172	local_irq_enable();
173	mdelay(8);
174	local_irq_disable();
175
176	p = strchr (reboot_command, '\n');
177	if (p) *p = 0;
178	if (!serial_console && prom_palette)
179		prom_palette (1);
180	if (cmd)
181		prom_reboot(cmd);
182	if (*reboot_command)
183		prom_reboot(reboot_command);
184	prom_feval ("reset");
185	panic("Reboot failed!");
186}
187
188EXPORT_SYMBOL(machine_restart);
189
190void machine_power_off(void)
191{
192#ifdef CONFIG_SUN_AUXIO
193	if (auxio_power_register && (!serial_console || scons_pwroff))
194		*auxio_power_register |= AUXIO_POWER_OFF;
195#endif
196	machine_halt();
197}
198
199EXPORT_SYMBOL(machine_power_off);
200
201static DEFINE_SPINLOCK(sparc_backtrace_lock);
202
203void __show_backtrace(unsigned long fp)
204{
205	struct reg_window *rw;
206	unsigned long flags;
207	int cpu = smp_processor_id();
208
209	spin_lock_irqsave(&sparc_backtrace_lock, flags);
210
211	rw = (struct reg_window *)fp;
212        while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
213            !(((unsigned long) rw) & 0x7)) {
214		printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
215		       "FP[%08lx] CALLER[%08lx]: ", cpu,
216		       rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
217		       rw->ins[4], rw->ins[5],
218		       rw->ins[6],
219		       rw->ins[7]);
220		print_symbol("%s\n", rw->ins[7]);
221		rw = (struct reg_window *) rw->ins[6];
222	}
223	spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
224}
225
226#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
227#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
228#define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
229
230void show_backtrace(void)
231{
232	unsigned long fp;
233
234	__SAVE; __SAVE; __SAVE; __SAVE;
235	__SAVE; __SAVE; __SAVE; __SAVE;
236	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
237	__RESTORE; __RESTORE; __RESTORE; __RESTORE;
238
239	__GET_FP(fp);
240
241	__show_backtrace(fp);
242}
243
244#ifdef CONFIG_SMP
245void smp_show_backtrace_all_cpus(void)
246{
247	xc0((smpfunc_t) show_backtrace);
248	show_backtrace();
249}
250#endif
251
252#if 0
253void show_stackframe(struct sparc_stackf *sf)
254{
255	unsigned long size;
256	unsigned long *stk;
257	int i;
258
259	printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
260	       "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
261	       sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
262	       sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
263	printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
264	       "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
265	       sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
266	       sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
267	printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
268	       "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
269	       (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
270	       sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
271	       sf->xxargs[0]);
272	size = ((unsigned long)sf->fp) - ((unsigned long)sf);
273	size -= STACKFRAME_SZ;
274	stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
275	i = 0;
276	do {
277		printk("s%d: %08lx\n", i++, *stk++);
278	} while ((size -= sizeof(unsigned long)));
279}
280#endif
281
282void show_regs(struct pt_regs *r)
283{
284	struct reg_window *rw = (struct reg_window *) r->u_regs[14];
285
286        printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx    %s\n",
287	       r->psr, r->pc, r->npc, r->y, print_tainted());
288	print_symbol("PC: <%s>\n", r->pc);
289	printk("%%G: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
290	       r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
291	       r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
292	printk("%%O: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
293	       r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
294	       r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
295	print_symbol("RPC: <%s>\n", r->u_regs[15]);
296
297	printk("%%L: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
298	       rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
299	       rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
300	printk("%%I: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
301	       rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
302	       rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
303}
304
305/*
306 * The show_stack is an external API which we do not use ourselves.
307 * The oops is printed in die_if_kernel.
308 */
309void show_stack(struct task_struct *tsk, unsigned long *_ksp)
310{
311	unsigned long pc, fp;
312	unsigned long task_base;
313	struct reg_window *rw;
314	int count = 0;
315
316	if (tsk != NULL)
317		task_base = (unsigned long) tsk->thread_info;
318	else
319		task_base = (unsigned long) current_thread_info();
320
321	fp = (unsigned long) _ksp;
322	do {
323		/* Bogus frame pointer? */
324		if (fp < (task_base + sizeof(struct thread_info)) ||
325		    fp >= (task_base + (PAGE_SIZE << 1)))
326			break;
327		rw = (struct reg_window *) fp;
328		pc = rw->ins[7];
329		printk("[%08lx : ", pc);
330		print_symbol("%s ] ", pc);
331		fp = rw->ins[6];
332	} while (++count < 16);
333	printk("\n");
334}
335
336/*
337 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
338 */
339unsigned 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 */
347void 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
366void 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
400static __inline__ struct sparc_stackf __user *
401clone_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
428asmlinkage 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 */
457extern void ret_from_fork(void);
458
459int 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 */
573void 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 */
605int 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 */
655asmlinkage 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	}
678out:
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 */
690pid_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
716unsigned 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
743out:
744	return ret;
745}
746