PageRenderTime 81ms CodeModel.GetById 17ms app.highlight 56ms RepoModel.GetById 1ms app.codeStats 0ms

/arch/ppc/kernel/process.c

https://bitbucket.org/evzijst/gittest
C | 781 lines | 601 code | 72 blank | 108 comment | 137 complexity | cd3776f07532f914afb72a51c1c525ce MD5 | raw file
  1/*
  2 *  arch/ppc/kernel/process.c
  3 *
  4 *  Derived from "arch/i386/kernel/process.c"
  5 *    Copyright (C) 1995  Linus Torvalds
  6 *
  7 *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
  8 *  Paul Mackerras (paulus@cs.anu.edu.au)
  9 *
 10 *  PowerPC version
 11 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 12 *
 13 *  This program is free software; you can redistribute it and/or
 14 *  modify it under the terms of the GNU General Public License
 15 *  as published by the Free Software Foundation; either version
 16 *  2 of the License, or (at your option) any later version.
 17 *
 18 */
 19
 20#include <linux/config.h>
 21#include <linux/errno.h>
 22#include <linux/sched.h>
 23#include <linux/kernel.h>
 24#include <linux/mm.h>
 25#include <linux/smp.h>
 26#include <linux/smp_lock.h>
 27#include <linux/stddef.h>
 28#include <linux/unistd.h>
 29#include <linux/ptrace.h>
 30#include <linux/slab.h>
 31#include <linux/user.h>
 32#include <linux/elf.h>
 33#include <linux/init.h>
 34#include <linux/prctl.h>
 35#include <linux/init_task.h>
 36#include <linux/module.h>
 37#include <linux/kallsyms.h>
 38#include <linux/mqueue.h>
 39#include <linux/hardirq.h>
 40
 41#include <asm/pgtable.h>
 42#include <asm/uaccess.h>
 43#include <asm/system.h>
 44#include <asm/io.h>
 45#include <asm/processor.h>
 46#include <asm/mmu.h>
 47#include <asm/prom.h>
 48
 49extern unsigned long _get_SP(void);
 50
 51struct task_struct *last_task_used_math = NULL;
 52struct task_struct *last_task_used_altivec = NULL;
 53struct task_struct *last_task_used_spe = NULL;
 54
 55static struct fs_struct init_fs = INIT_FS;
 56static struct files_struct init_files = INIT_FILES;
 57static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 58static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 59struct mm_struct init_mm = INIT_MM(init_mm);
 60EXPORT_SYMBOL(init_mm);
 61
 62/* this is 8kB-aligned so we can get to the thread_info struct
 63   at the base of it from the stack pointer with 1 integer instruction. */
 64union thread_union init_thread_union
 65	__attribute__((__section__(".data.init_task"))) =
 66{ INIT_THREAD_INFO(init_task) };
 67
 68/* initial task structure */
 69struct task_struct init_task = INIT_TASK(init_task);
 70EXPORT_SYMBOL(init_task);
 71
 72/* only used to get secondary processor up */
 73struct task_struct *current_set[NR_CPUS] = {&init_task, };
 74
 75#undef SHOW_TASK_SWITCHES
 76#undef CHECK_STACK
 77
 78#if defined(CHECK_STACK)
 79unsigned long
 80kernel_stack_top(struct task_struct *tsk)
 81{
 82	return ((unsigned long)tsk) + sizeof(union task_union);
 83}
 84
 85unsigned long
 86task_top(struct task_struct *tsk)
 87{
 88	return ((unsigned long)tsk) + sizeof(struct thread_info);
 89}
 90
 91/* check to make sure the kernel stack is healthy */
 92int check_stack(struct task_struct *tsk)
 93{
 94	unsigned long stack_top = kernel_stack_top(tsk);
 95	unsigned long tsk_top = task_top(tsk);
 96	int ret = 0;
 97
 98#if 0
 99	/* check thread magic */
100	if ( tsk->thread.magic != THREAD_MAGIC )
101	{
102		ret |= 1;
103		printk("thread.magic bad: %08x\n", tsk->thread.magic);
104	}
105#endif
106
107	if ( !tsk )
108		printk("check_stack(): tsk bad tsk %p\n",tsk);
109
110	/* check if stored ksp is bad */
111	if ( (tsk->thread.ksp > stack_top) || (tsk->thread.ksp < tsk_top) )
112	{
113		printk("stack out of bounds: %s/%d\n"
114		       " tsk_top %08lx ksp %08lx stack_top %08lx\n",
115		       tsk->comm,tsk->pid,
116		       tsk_top, tsk->thread.ksp, stack_top);
117		ret |= 2;
118	}
119
120	/* check if stack ptr RIGHT NOW is bad */
121	if ( (tsk == current) && ((_get_SP() > stack_top ) || (_get_SP() < tsk_top)) )
122	{
123		printk("current stack ptr out of bounds: %s/%d\n"
124		       " tsk_top %08lx sp %08lx stack_top %08lx\n",
125		       current->comm,current->pid,
126		       tsk_top, _get_SP(), stack_top);
127		ret |= 4;
128	}
129
130#if 0
131	/* check amount of free stack */
132	for ( i = (unsigned long *)task_top(tsk) ; i < kernel_stack_top(tsk) ; i++ )
133	{
134		if ( !i )
135			printk("check_stack(): i = %p\n", i);
136		if ( *i != 0 )
137		{
138			/* only notify if it's less than 900 bytes */
139			if ( (i - (unsigned long *)task_top(tsk))  < 900 )
140				printk("%d bytes free on stack\n",
141				       i - task_top(tsk));
142			break;
143		}
144	}
145#endif
146
147	if (ret)
148	{
149		panic("bad kernel stack");
150	}
151	return(ret);
152}
153#endif /* defined(CHECK_STACK) */
154
155#ifdef CONFIG_ALTIVEC
156int
157dump_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
158{
159	if (regs->msr & MSR_VEC)
160		giveup_altivec(current);
161	memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
162	return 1;
163}
164
165void
166enable_kernel_altivec(void)
167{
168	WARN_ON(preemptible());
169
170#ifdef CONFIG_SMP
171	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
172		giveup_altivec(current);
173	else
174		giveup_altivec(NULL);	/* just enable AltiVec for kernel - force */
175#else
176	giveup_altivec(last_task_used_altivec);
177#endif /* __SMP __ */
178}
179EXPORT_SYMBOL(enable_kernel_altivec);
180#endif /* CONFIG_ALTIVEC */
181
182#ifdef CONFIG_SPE
183int
184dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
185{
186	if (regs->msr & MSR_SPE)
187		giveup_spe(current);
188	/* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
189	memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
190	return 1;
191}
192
193void
194enable_kernel_spe(void)
195{
196	WARN_ON(preemptible());
197
198#ifdef CONFIG_SMP
199	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
200		giveup_spe(current);
201	else
202		giveup_spe(NULL);	/* just enable SPE for kernel - force */
203#else
204	giveup_spe(last_task_used_spe);
205#endif /* __SMP __ */
206}
207EXPORT_SYMBOL(enable_kernel_spe);
208#endif /* CONFIG_SPE */
209
210void
211enable_kernel_fp(void)
212{
213	WARN_ON(preemptible());
214
215#ifdef CONFIG_SMP
216	if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
217		giveup_fpu(current);
218	else
219		giveup_fpu(NULL);	/* just enables FP for kernel */
220#else
221	giveup_fpu(last_task_used_math);
222#endif /* CONFIG_SMP */
223}
224EXPORT_SYMBOL(enable_kernel_fp);
225
226int
227dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
228{
229	preempt_disable();
230	if (tsk->thread.regs && (tsk->thread.regs->msr & MSR_FP))
231		giveup_fpu(tsk);
232	preempt_enable();
233	memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
234	return 1;
235}
236
237struct task_struct *__switch_to(struct task_struct *prev,
238	struct task_struct *new)
239{
240	struct thread_struct *new_thread, *old_thread;
241	unsigned long s;
242	struct task_struct *last;
243
244	local_irq_save(s);
245#ifdef CHECK_STACK
246	check_stack(prev);
247	check_stack(new);
248#endif
249
250#ifdef CONFIG_SMP
251	/* avoid complexity of lazy save/restore of fpu
252	 * by just saving it every time we switch out if
253	 * this task used the fpu during the last quantum.
254	 *
255	 * If it tries to use the fpu again, it'll trap and
256	 * reload its fp regs.  So we don't have to do a restore
257	 * every switch, just a save.
258	 *  -- Cort
259	 */
260	if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
261		giveup_fpu(prev);
262#ifdef CONFIG_ALTIVEC
263	/*
264	 * If the previous thread used altivec in the last quantum
265	 * (thus changing altivec regs) then save them.
266	 * We used to check the VRSAVE register but not all apps
267	 * set it, so we don't rely on it now (and in fact we need
268	 * to save & restore VSCR even if VRSAVE == 0).  -- paulus
269	 *
270	 * On SMP we always save/restore altivec regs just to avoid the
271	 * complexity of changing processors.
272	 *  -- Cort
273	 */
274	if ((prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)))
275		giveup_altivec(prev);
276#endif /* CONFIG_ALTIVEC */
277#ifdef CONFIG_SPE
278	/*
279	 * If the previous thread used spe in the last quantum
280	 * (thus changing spe regs) then save them.
281	 *
282	 * On SMP we always save/restore spe regs just to avoid the
283	 * complexity of changing processors.
284	 */
285	if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
286		giveup_spe(prev);
287#endif /* CONFIG_SPE */
288#endif /* CONFIG_SMP */
289
290	/* Avoid the trap.  On smp this this never happens since
291	 * we don't set last_task_used_altivec -- Cort
292	 */
293	if (new->thread.regs && last_task_used_altivec == new)
294		new->thread.regs->msr |= MSR_VEC;
295#ifdef CONFIG_SPE
296	/* Avoid the trap.  On smp this this never happens since
297	 * we don't set last_task_used_spe
298	 */
299	if (new->thread.regs && last_task_used_spe == new)
300		new->thread.regs->msr |= MSR_SPE;
301#endif /* CONFIG_SPE */
302	new_thread = &new->thread;
303	old_thread = &current->thread;
304	last = _switch(old_thread, new_thread);
305	local_irq_restore(s);
306	return last;
307}
308
309void show_regs(struct pt_regs * regs)
310{
311	int i, trap;
312
313	printk("NIP: %08lX LR: %08lX SP: %08lX REGS: %p TRAP: %04lx    %s\n",
314	       regs->nip, regs->link, regs->gpr[1], regs, regs->trap,
315	       print_tainted());
316	printk("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
317	       regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
318	       regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
319	       regs->msr&MSR_IR ? 1 : 0,
320	       regs->msr&MSR_DR ? 1 : 0);
321	trap = TRAP(regs);
322	if (trap == 0x300 || trap == 0x600)
323		printk("DAR: %08lX, DSISR: %08lX\n", regs->dar, regs->dsisr);
324	printk("TASK = %p[%d] '%s' THREAD: %p\n",
325	       current, current->pid, current->comm, current->thread_info);
326	printk("Last syscall: %ld ", current->thread.last_syscall);
327
328#ifdef CONFIG_SMP
329	printk(" CPU: %d", smp_processor_id());
330#endif /* CONFIG_SMP */
331
332	for (i = 0;  i < 32;  i++) {
333		long r;
334		if ((i % 8) == 0)
335			printk("\n" KERN_INFO "GPR%02d: ", i);
336		if (__get_user(r, &regs->gpr[i]))
337			break;
338		printk("%08lX ", r);
339		if (i == 12 && !FULL_REGS(regs))
340			break;
341	}
342	printk("\n");
343#ifdef CONFIG_KALLSYMS
344	/*
345	 * Lookup NIP late so we have the best change of getting the
346	 * above info out without failing
347	 */
348	printk("NIP [%08lx] ", regs->nip);
349	print_symbol("%s\n", regs->nip);
350	printk("LR [%08lx] ", regs->link);
351	print_symbol("%s\n", regs->link);
352#endif
353	show_stack(current, (unsigned long *) regs->gpr[1]);
354}
355
356void exit_thread(void)
357{
358	if (last_task_used_math == current)
359		last_task_used_math = NULL;
360	if (last_task_used_altivec == current)
361		last_task_used_altivec = NULL;
362#ifdef CONFIG_SPE
363	if (last_task_used_spe == current)
364		last_task_used_spe = NULL;
365#endif
366}
367
368void flush_thread(void)
369{
370	if (last_task_used_math == current)
371		last_task_used_math = NULL;
372	if (last_task_used_altivec == current)
373		last_task_used_altivec = NULL;
374#ifdef CONFIG_SPE
375	if (last_task_used_spe == current)
376		last_task_used_spe = NULL;
377#endif
378}
379
380void
381release_thread(struct task_struct *t)
382{
383}
384
385/*
386 * This gets called before we allocate a new thread and copy
387 * the current task into it.
388 */
389void prepare_to_copy(struct task_struct *tsk)
390{
391	struct pt_regs *regs = tsk->thread.regs;
392
393	if (regs == NULL)
394		return;
395	preempt_disable();
396	if (regs->msr & MSR_FP)
397		giveup_fpu(current);
398#ifdef CONFIG_ALTIVEC
399	if (regs->msr & MSR_VEC)
400		giveup_altivec(current);
401#endif /* CONFIG_ALTIVEC */
402#ifdef CONFIG_SPE
403	if (regs->msr & MSR_SPE)
404		giveup_spe(current);
405#endif /* CONFIG_SPE */
406	preempt_enable();
407}
408
409/*
410 * Copy a thread..
411 */
412int
413copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
414	    unsigned long unused,
415	    struct task_struct *p, struct pt_regs *regs)
416{
417	struct pt_regs *childregs, *kregs;
418	extern void ret_from_fork(void);
419	unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
420	unsigned long childframe;
421
422	CHECK_FULL_REGS(regs);
423	/* Copy registers */
424	sp -= sizeof(struct pt_regs);
425	childregs = (struct pt_regs *) sp;
426	*childregs = *regs;
427	if ((childregs->msr & MSR_PR) == 0) {
428		/* for kernel thread, set `current' and stackptr in new task */
429		childregs->gpr[1] = sp + sizeof(struct pt_regs);
430		childregs->gpr[2] = (unsigned long) p;
431		p->thread.regs = NULL;	/* no user register state */
432	} else {
433		childregs->gpr[1] = usp;
434		p->thread.regs = childregs;
435		if (clone_flags & CLONE_SETTLS)
436			childregs->gpr[2] = childregs->gpr[6];
437	}
438	childregs->gpr[3] = 0;  /* Result from fork() */
439	sp -= STACK_FRAME_OVERHEAD;
440	childframe = sp;
441
442	/*
443	 * The way this works is that at some point in the future
444	 * some task will call _switch to switch to the new task.
445	 * That will pop off the stack frame created below and start
446	 * the new task running at ret_from_fork.  The new task will
447	 * do some house keeping and then return from the fork or clone
448	 * system call, using the stack frame created above.
449	 */
450	sp -= sizeof(struct pt_regs);
451	kregs = (struct pt_regs *) sp;
452	sp -= STACK_FRAME_OVERHEAD;
453	p->thread.ksp = sp;
454	kregs->nip = (unsigned long)ret_from_fork;
455
456	p->thread.last_syscall = -1;
457
458	return 0;
459}
460
461/*
462 * Set up a thread for executing a new program
463 */
464void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp)
465{
466	set_fs(USER_DS);
467	memset(regs->gpr, 0, sizeof(regs->gpr));
468	regs->ctr = 0;
469	regs->link = 0;
470	regs->xer = 0;
471	regs->ccr = 0;
472	regs->mq = 0;
473	regs->nip = nip;
474	regs->gpr[1] = sp;
475	regs->msr = MSR_USER;
476	if (last_task_used_math == current)
477		last_task_used_math = NULL;
478	if (last_task_used_altivec == current)
479		last_task_used_altivec = NULL;
480#ifdef CONFIG_SPE
481	if (last_task_used_spe == current)
482		last_task_used_spe = NULL;
483#endif
484	memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
485	current->thread.fpscr = 0;
486#ifdef CONFIG_ALTIVEC
487	memset(current->thread.vr, 0, sizeof(current->thread.vr));
488	memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
489	current->thread.vrsave = 0;
490	current->thread.used_vr = 0;
491#endif /* CONFIG_ALTIVEC */
492#ifdef CONFIG_SPE
493	memset(current->thread.evr, 0, sizeof(current->thread.evr));
494	current->thread.acc = 0;
495	current->thread.spefscr = 0;
496	current->thread.used_spe = 0;
497#endif /* CONFIG_SPE */
498}
499
500#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
501		| PR_FP_EXC_RES | PR_FP_EXC_INV)
502
503int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
504{
505	struct pt_regs *regs = tsk->thread.regs;
506
507	/* This is a bit hairy.  If we are an SPE enabled  processor
508	 * (have embedded fp) we store the IEEE exception enable flags in
509	 * fpexc_mode.  fpexc_mode is also used for setting FP exception
510	 * mode (asyn, precise, disabled) for 'Classic' FP. */
511	if (val & PR_FP_EXC_SW_ENABLE) {
512#ifdef CONFIG_SPE
513		tsk->thread.fpexc_mode = val &
514			(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
515#else
516		return -EINVAL;
517#endif
518	} else {
519		/* on a CONFIG_SPE this does not hurt us.  The bits that
520		 * __pack_fe01 use do not overlap with bits used for
521		 * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
522		 * on CONFIG_SPE implementations are reserved so writing to
523		 * them does not change anything */
524		if (val > PR_FP_EXC_PRECISE)
525			return -EINVAL;
526		tsk->thread.fpexc_mode = __pack_fe01(val);
527		if (regs != NULL && (regs->msr & MSR_FP) != 0)
528			regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
529				| tsk->thread.fpexc_mode;
530	}
531	return 0;
532}
533
534int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
535{
536	unsigned int val;
537
538	if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
539#ifdef CONFIG_SPE
540		val = tsk->thread.fpexc_mode;
541#else
542		return -EINVAL;
543#endif
544	else
545		val = __unpack_fe01(tsk->thread.fpexc_mode);
546	return put_user(val, (unsigned int __user *) adr);
547}
548
549int sys_clone(unsigned long clone_flags, unsigned long usp,
550	      int __user *parent_tidp, void __user *child_threadptr,
551	      int __user *child_tidp, int p6,
552	      struct pt_regs *regs)
553{
554	CHECK_FULL_REGS(regs);
555	if (usp == 0)
556		usp = regs->gpr[1];	/* stack pointer for child */
557 	return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
558}
559
560int sys_fork(int p1, int p2, int p3, int p4, int p5, int p6,
561	     struct pt_regs *regs)
562{
563	CHECK_FULL_REGS(regs);
564	return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
565}
566
567int sys_vfork(int p1, int p2, int p3, int p4, int p5, int p6,
568	      struct pt_regs *regs)
569{
570	CHECK_FULL_REGS(regs);
571	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
572			regs, 0, NULL, NULL);
573}
574
575int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
576	       unsigned long a3, unsigned long a4, unsigned long a5,
577	       struct pt_regs *regs)
578{
579	int error;
580	char * filename;
581
582	filename = getname((char __user *) a0);
583	error = PTR_ERR(filename);
584	if (IS_ERR(filename))
585		goto out;
586	preempt_disable();
587	if (regs->msr & MSR_FP)
588		giveup_fpu(current);
589#ifdef CONFIG_ALTIVEC
590	if (regs->msr & MSR_VEC)
591		giveup_altivec(current);
592#endif /* CONFIG_ALTIVEC */
593#ifdef CONFIG_SPE
594	if (regs->msr & MSR_SPE)
595		giveup_spe(current);
596#endif /* CONFIG_SPE */
597	preempt_enable();
598	error = do_execve(filename, (char __user *__user *) a1,
599			  (char __user *__user *) a2, regs);
600	if (error == 0) {
601		task_lock(current);
602		current->ptrace &= ~PT_DTRACE;
603		task_unlock(current);
604	}
605	putname(filename);
606out:
607	return error;
608}
609
610void dump_stack(void)
611{
612	show_stack(current, NULL);
613}
614
615EXPORT_SYMBOL(dump_stack);
616
617void show_stack(struct task_struct *tsk, unsigned long *stack)
618{
619	unsigned long sp, stack_top, prev_sp, ret;
620	int count = 0;
621	unsigned long next_exc = 0;
622	struct pt_regs *regs;
623	extern char ret_from_except, ret_from_except_full, ret_from_syscall;
624
625	sp = (unsigned long) stack;
626	if (tsk == NULL)
627		tsk = current;
628	if (sp == 0) {
629		if (tsk == current)
630			asm("mr %0,1" : "=r" (sp));
631		else
632			sp = tsk->thread.ksp;
633	}
634
635	prev_sp = (unsigned long) (tsk->thread_info + 1);
636	stack_top = (unsigned long) tsk->thread_info + THREAD_SIZE;
637	while (count < 16 && sp > prev_sp && sp < stack_top && (sp & 3) == 0) {
638		if (count == 0) {
639			printk("Call trace:");
640#ifdef CONFIG_KALLSYMS
641			printk("\n");
642#endif
643		} else {
644			if (next_exc) {
645				ret = next_exc;
646				next_exc = 0;
647			} else
648				ret = *(unsigned long *)(sp + 4);
649			printk(" [%08lx] ", ret);
650#ifdef CONFIG_KALLSYMS
651			print_symbol("%s", ret);
652			printk("\n");
653#endif
654			if (ret == (unsigned long) &ret_from_except
655			    || ret == (unsigned long) &ret_from_except_full
656			    || ret == (unsigned long) &ret_from_syscall) {
657				/* sp + 16 points to an exception frame */
658				regs = (struct pt_regs *) (sp + 16);
659				if (sp + 16 + sizeof(*regs) <= stack_top)
660					next_exc = regs->nip;
661			}
662		}
663		++count;
664		sp = *(unsigned long *)sp;
665	}
666#ifndef CONFIG_KALLSYMS
667	if (count > 0)
668		printk("\n");
669#endif
670}
671
672#if 0
673/*
674 * Low level print for debugging - Cort
675 */
676int __init ll_printk(const char *fmt, ...)
677{
678        va_list args;
679	char buf[256];
680        int i;
681
682        va_start(args, fmt);
683        i=vsprintf(buf,fmt,args);
684	ll_puts(buf);
685        va_end(args);
686        return i;
687}
688
689int lines = 24, cols = 80;
690int orig_x = 0, orig_y = 0;
691
692void puthex(unsigned long val)
693{
694	unsigned char buf[10];
695	int i;
696	for (i = 7;  i >= 0;  i--)
697	{
698		buf[i] = "0123456789ABCDEF"[val & 0x0F];
699		val >>= 4;
700	}
701	buf[8] = '\0';
702	prom_print(buf);
703}
704
705void __init ll_puts(const char *s)
706{
707	int x,y;
708	char *vidmem = (char *)/*(_ISA_MEM_BASE + 0xB8000) */0xD00B8000;
709	char c;
710	extern int mem_init_done;
711
712	if ( mem_init_done ) /* assume this means we can printk */
713	{
714		printk(s);
715		return;
716	}
717
718#if 0
719	if ( have_of )
720	{
721		prom_print(s);
722		return;
723	}
724#endif
725
726	/*
727	 * can't ll_puts on chrp without openfirmware yet.
728	 * vidmem just needs to be setup for it.
729	 * -- Cort
730	 */
731	if ( _machine != _MACH_prep )
732		return;
733	x = orig_x;
734	y = orig_y;
735
736	while ( ( c = *s++ ) != '\0' ) {
737		if ( c == '\n' ) {
738			x = 0;
739			if ( ++y >= lines ) {
740				/*scroll();*/
741				/*y--;*/
742				y = 0;
743			}
744		} else {
745			vidmem [ ( x + cols * y ) * 2 ] = c;
746			if ( ++x >= cols ) {
747				x = 0;
748				if ( ++y >= lines ) {
749					/*scroll();*/
750					/*y--;*/
751					y = 0;
752				}
753			}
754		}
755	}
756
757	orig_x = x;
758	orig_y = y;
759}
760#endif
761
762unsigned long get_wchan(struct task_struct *p)
763{
764	unsigned long ip, sp;
765	unsigned long stack_page = (unsigned long) p->thread_info;
766	int count = 0;
767	if (!p || p == current || p->state == TASK_RUNNING)
768		return 0;
769	sp = p->thread.ksp;
770	do {
771		sp = *(unsigned long *)sp;
772		if (sp < stack_page || sp >= stack_page + 8188)
773			return 0;
774		if (count > 0) {
775			ip = *(unsigned long *)(sp + 4);
776			if (!in_sched_functions(ip))
777				return ip;
778		}
779	} while (count++ < 16);
780	return 0;
781}