[deliverable/linux.git] / arch / avr32 / kernel / process.c

/*
 * Copyright (C) 2004-2006 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
#include <linux/pm.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/reboot.h>
#include <linux/tick.h>
#include <linux/uaccess.h>
#include <linux/unistd.h>

#include <asm/sysreg.h>
#include <asm/ocd.h>
#include <asm/syscalls.h>

#include <mach/pm.h>

void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);

/*
 * This file handles the architecture-dependent parts of process handling..
 */

void cpu_idle(void)
{
	/* endless idle loop with no priority at all */
	while (1) {
		tick_nohz_idle_enter();
		rcu_idle_enter();
		while (!need_resched())
			cpu_idle_sleep();
		rcu_idle_exit();
		tick_nohz_idle_exit();
		schedule_preempt_disabled();
	}
}

void machine_halt(void)
{
	/*
	 * Enter Stop mode. The 32 kHz oscillator will keep running so
	 * the RTC will keep the time properly and the system will
	 * boot quickly.
	 */
	asm volatile("sleep 3\n\t"
		     "sub pc, -2");
}

void machine_power_off(void)
{
	if (pm_power_off)
		pm_power_off();
}

void machine_restart(char *cmd)
{
	ocd_write(DC, (1 << OCD_DC_DBE_BIT));
	ocd_write(DC, (1 << OCD_DC_RES_BIT));
	while (1) ;
}

/*
 * Free current thread data structures etc
 */
void exit_thread(void)
{
	ocd_disable(current);
}

void flush_thread(void)
{
	/* nothing to do */
}

void release_thread(struct task_struct *dead_task)
{
	/* do nothing */
}

static void dump_mem(const char *str, const char *log_lvl,
		     unsigned long bottom, unsigned long top)
{
	unsigned long p;
	int i;

	printk("%s%s(0x%08lx to 0x%08lx)\n", log_lvl, str, bottom, top);

	for (p = bottom & ~31; p < top; ) {
		printk("%s%04lx: ", log_lvl, p & 0xffff);

		for (i = 0; i < 8; i++, p += 4) {
			unsigned int val;

			if (p < bottom || p >= top)
				printk("         ");
			else {
				if (__get_user(val, (unsigned int __user *)p)) {
					printk("\n");
					goto out;
				}
				printk("%08x ", val);
			}
		}
		printk("\n");
	}

out:
	return;
}

static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
{
	return (p > (unsigned long)tinfo)
		&& (p < (unsigned long)tinfo + THREAD_SIZE - 3);
}

#ifdef CONFIG_FRAME_POINTER
static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
			       struct pt_regs *regs, const char *log_lvl)
{
	unsigned long lr, fp;
	struct thread_info *tinfo;

	if (regs)
		fp = regs->r7;
	else if (tsk == current)
		asm("mov %0, r7" : "=r"(fp));
	else
		fp = tsk->thread.cpu_context.r7;

	/*
	 * Walk the stack as long as the frame pointer (a) is within
	 * the kernel stack of the task, and (b) it doesn't move
	 * downwards.
	 */
	tinfo = task_thread_info(tsk);
	printk("%sCall trace:\n", log_lvl);
	while (valid_stack_ptr(tinfo, fp)) {
		unsigned long new_fp;

		lr = *(unsigned long *)fp;
#ifdef CONFIG_KALLSYMS
		printk("%s [<%08lx>] ", log_lvl, lr);
#else
		printk(" [<%08lx>] ", lr);
#endif
		print_symbol("%s\n", lr);

		new_fp = *(unsigned long *)(fp + 4);
		if (new_fp <= fp)
			break;
		fp = new_fp;
	}
	printk("\n");
}
#else
static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
			       struct pt_regs *regs, const char *log_lvl)
{
	unsigned long addr;

	printk("%sCall trace:\n", log_lvl);

	while (!kstack_end(sp)) {
		addr = *sp++;
		if (kernel_text_address(addr)) {
#ifdef CONFIG_KALLSYMS
			printk("%s [<%08lx>] ", log_lvl, addr);
#else
			printk(" [<%08lx>] ", addr);
#endif
			print_symbol("%s\n", addr);
		}
	}
	printk("\n");
}
#endif

void show_stack_log_lvl(struct task_struct *tsk, unsigned long sp,
			struct pt_regs *regs, const char *log_lvl)
{
	struct thread_info *tinfo;

	if (sp == 0) {
		if (tsk)
			sp = tsk->thread.cpu_context.ksp;
		else
			sp = (unsigned long)&tinfo;
	}
	if (!tsk)
		tsk = current;

	tinfo = task_thread_info(tsk);

	if (valid_stack_ptr(tinfo, sp)) {
		dump_mem("Stack: ", log_lvl, sp,
			 THREAD_SIZE + (unsigned long)tinfo);
		show_trace_log_lvl(tsk, (unsigned long *)sp, regs, log_lvl);
	}
}

void show_stack(struct task_struct *tsk, unsigned long *stack)
{
	show_stack_log_lvl(tsk, (unsigned long)stack, NULL, "");
}

void dump_stack(void)
{
	unsigned long stack;

	show_trace_log_lvl(current, &stack, NULL, "");
}
EXPORT_SYMBOL(dump_stack);

static const char *cpu_modes[] = {
	"Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
	"Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
};

void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl)
{
	unsigned long sp = regs->sp;
	unsigned long lr = regs->lr;
	unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;

	if (!user_mode(regs)) {
		sp = (unsigned long)regs + FRAME_SIZE_FULL;

		printk("%s", log_lvl);
		print_symbol("PC is at %s\n", instruction_pointer(regs));
		printk("%s", log_lvl);
		print_symbol("LR is at %s\n", lr);
	}

	printk("%spc : [<%08lx>]    lr : [<%08lx>]    %s\n"
	       "%ssp : %08lx  r12: %08lx  r11: %08lx\n",
	       log_lvl, instruction_pointer(regs), lr, print_tainted(),
	       log_lvl, sp, regs->r12, regs->r11);
	printk("%sr10: %08lx  r9 : %08lx  r8 : %08lx\n",
	       log_lvl, regs->r10, regs->r9, regs->r8);
	printk("%sr7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
	       log_lvl, regs->r7, regs->r6, regs->r5, regs->r4);
	printk("%sr3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
	       log_lvl, regs->r3, regs->r2, regs->r1, regs->r0);
	printk("%sFlags: %c%c%c%c%c\n", log_lvl,
	       regs->sr & SR_Q ? 'Q' : 'q',
	       regs->sr & SR_V ? 'V' : 'v',
	       regs->sr & SR_N ? 'N' : 'n',
	       regs->sr & SR_Z ? 'Z' : 'z',
	       regs->sr & SR_C ? 'C' : 'c');
	printk("%sMode bits: %c%c%c%c%c%c%c%c%c%c\n", log_lvl,
	       regs->sr & SR_H ? 'H' : 'h',
	       regs->sr & SR_J ? 'J' : 'j',
	       regs->sr & SR_DM ? 'M' : 'm',
	       regs->sr & SR_D ? 'D' : 'd',
	       regs->sr & SR_EM ? 'E' : 'e',
	       regs->sr & SR_I3M ? '3' : '.',
	       regs->sr & SR_I2M ? '2' : '.',
	       regs->sr & SR_I1M ? '1' : '.',
	       regs->sr & SR_I0M ? '0' : '.',
	       regs->sr & SR_GM ? 'G' : 'g');
	printk("%sCPU Mode: %s\n", log_lvl, cpu_modes[mode]);
	printk("%sProcess: %s [%d] (task: %p thread: %p)\n",
	       log_lvl, current->comm, current->pid, current,
	       task_thread_info(current));
}

void show_regs(struct pt_regs *regs)
{
	unsigned long sp = regs->sp;

	if (!user_mode(regs))
		sp = (unsigned long)regs + FRAME_SIZE_FULL;

	show_regs_log_lvl(regs, "");
	show_trace_log_lvl(current, (unsigned long *)sp, regs, "");
}
EXPORT_SYMBOL(show_regs);

/* Fill in the fpu structure for a core dump. This is easy -- we don't have any */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
	/* Not valid */
	return 0;
}

asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
asmlinkage void syscall_return(void);

int copy_thread(unsigned long clone_flags, unsigned long usp,
		unsigned long arg,
		struct task_struct *p, struct pt_regs *regs)
{
	struct pt_regs *childregs = task_pt_regs(p);

	if (unlikely(!regs)) {
		memset(childregs, 0, sizeof(struct pt_regs));
		p->thread.cpu_context.r0 = arg;
		p->thread.cpu_context.r1 = usp; /* fn */
		p->thread.cpu_context.r2 = syscall_return;
		p->thread.cpu_context.pc = (unsigned long)ret_from_kernel_thread;
		childregs->sr = MODE_SUPERVISOR;
	} else {
		*childregs = *regs;
		childregs->sp = usp;
		childregs->r12 = 0; /* Set return value for child */
		p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
	}

	p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
	p->thread.cpu_context.ksp = (unsigned long)childregs;

	clear_tsk_thread_flag(p, TIF_DEBUG);
	if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))
		ocd_enable(p);

	return 0;
}

/* r12-r8 are dummy parameters to force the compiler to use the stack */
asmlinkage int sys_fork(struct pt_regs *regs)
{
	return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
}

asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
		void __user *parent_tidptr, void __user *child_tidptr,
		struct pt_regs *regs)
{
	if (!newsp)
		newsp = regs->sp;
	return do_fork(clone_flags, newsp, regs, 0, parent_tidptr,
			child_tidptr);
}

asmlinkage int sys_vfork(struct pt_regs *regs)
{
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs,
		       0, NULL, NULL);
}

/*
 * This function is supposed to answer the question "who called
 * schedule()?"
 */
unsigned long get_wchan(struct task_struct *p)
{
	unsigned long pc;
	unsigned long stack_page;

	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	stack_page = (unsigned long)task_stack_page(p);
	BUG_ON(!stack_page);

	/*
	 * The stored value of PC is either the address right after
	 * the call to __switch_to() or ret_from_fork.
	 */
	pc = thread_saved_pc(p);
	if (in_sched_functions(pc)) {
#ifdef CONFIG_FRAME_POINTER
		unsigned long fp = p->thread.cpu_context.r7;
		BUG_ON(fp < stack_page || fp > (THREAD_SIZE + stack_page));
		pc = *(unsigned long *)fp;
#else
		/*
		 * We depend on the frame size of schedule here, which
		 * is actually quite ugly. It might be possible to
		 * determine the frame size automatically at build
		 * time by doing this:
		 *   - compile sched.c
		 *   - disassemble the resulting sched.o
		 *   - look for 'sub sp,??' shortly after '<schedule>:'
		 */
		unsigned long sp = p->thread.cpu_context.ksp + 16;
		BUG_ON(sp < stack_page || sp > (THREAD_SIZE + stack_page));
		pc = *(unsigned long *)sp;
#endif
	}

	return pc;
}
Commit	Line	Data
5f97f7f9 HS	1	/*
	2	* Copyright (C) 2004-2006 Atmel Corporation
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8	#include <linux/sched.h>
	9	#include <linux/module.h>
	10	#include <linux/kallsyms.h>
	11	#include <linux/fs.h>
b3bc2c55	12	#include <linux/pm.h>
5f97f7f9	13	#include <linux/ptrace.h>
5a0e3ad6	14	#include <linux/slab.h>
5f97f7f9	15	#include <linux/reboot.h>
d45ad062	16	#include <linux/tick.h>
623b0355	17	#include <linux/uaccess.h>
5f97f7f9 HS	18	#include <linux/unistd.h>
	19
	20	#include <asm/sysreg.h>
	21	#include <asm/ocd.h>
c80ce2d5	22	#include <asm/syscalls.h>
5f97f7f9	23
3663b736	24	#include <mach/pm.h>
7e59128f	25
b3bc2c55	26	void (*pm_power_off)(void);
5f97f7f9 HS	27	EXPORT_SYMBOL(pm_power_off);
	28
	29	/*
	30	* This file handles the architecture-dependent parts of process handling..
	31	*/
	32
	33	void cpu_idle(void)
	34	{
	35	/* endless idle loop with no priority at all */
	36	while (1) {
1268fbc7 FW	37	tick_nohz_idle_enter();
1268fbc7 FW	38	rcu_idle_enter();
5f97f7f9	39	while (!need_resched())
19b7ce8b	40	cpu_idle_sleep();
1268fbc7 FW	41	rcu_idle_exit();
1268fbc7 FW	42	tick_nohz_idle_exit();
bd2f5536	43	schedule_preempt_disabled();
5f97f7f9 HS	44	}
	45	}
	46
	47	void machine_halt(void)
	48	{
c2eb5090 HS	49	/*
	50	* Enter Stop mode. The 32 kHz oscillator will keep running so
	51	* the RTC will keep the time properly and the system will
	52	* boot quickly.
	53	*/
	54	asm volatile("sleep 3\n\t"
	55	"sub pc, -2");
5f97f7f9 HS	56	}
	57
	58	void machine_power_off(void)
	59	{
ed3fa7c9 PM	60	if (pm_power_off)
ed3fa7c9 PM	61	pm_power_off();
5f97f7f9 HS	62	}
	63
	64	void machine_restart(char *cmd)
	65	{
8dfe8f29 HS	66	ocd_write(DC, (1 << OCD_DC_DBE_BIT));
8dfe8f29 HS	67	ocd_write(DC, (1 << OCD_DC_RES_BIT));
5f97f7f9 HS	68	while (1) ;
	69	}
	70
5f97f7f9 HS	71	/*
	72	* Free current thread data structures etc
	73	*/
	74	void exit_thread(void)
	75	{
13b54a50	76	ocd_disable(current);
5f97f7f9 HS	77	}
	78
	79	void flush_thread(void)
	80	{
	81	/* nothing to do */
	82	}
	83
	84	void release_thread(struct task_struct *dead_task)
	85	{
	86	/* do nothing */
	87	}
	88
623b0355 HS	89	static void dump_mem(const char str, const char log_lvl,
	90	unsigned long bottom, unsigned long top)
	91	{
	92	unsigned long p;
	93	int i;
	94
	95	printk("%s%s(0x%08lx to 0x%08lx)\n", log_lvl, str, bottom, top);
	96
	97	for (p = bottom & ~31; p < top; ) {
	98	printk("%s%04lx: ", log_lvl, p & 0xffff);
	99
	100	for (i = 0; i < 8; i++, p += 4) {
	101	unsigned int val;
	102
	103	if (p < bottom \|\| p >= top)
	104	printk(" ");
	105	else {
	106	if (__get_user(val, (unsigned int __user *)p)) {
	107	printk("\n");
	108	goto out;
	109	}
	110	printk("%08x ", val);
	111	}
	112	}
	113	printk("\n");
	114	}
	115
	116	out:
	117	return;
	118	}
	119
	120	static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
	121	{
	122	return (p > (unsigned long)tinfo)
	123	&& (p < (unsigned long)tinfo + THREAD_SIZE - 3);
	124	}
	125
	126	#ifdef CONFIG_FRAME_POINTER
	127	static void show_trace_log_lvl(struct task_struct tsk, unsigned long sp,
	128	struct pt_regs regs, const char log_lvl)
	129	{
	130	unsigned long lr, fp;
	131	struct thread_info *tinfo;
	132
	133	if (regs)
	134	fp = regs->r7;
	135	else if (tsk == current)
	136	asm("mov %0, r7" : "=r"(fp));
	137	else
	138	fp = tsk->thread.cpu_context.r7;
	139
	140	/*
	141	* Walk the stack as long as the frame pointer (a) is within
	142	* the kernel stack of the task, and (b) it doesn't move
	143	* downwards.
	144	*/
	145	tinfo = task_thread_info(tsk);
	146	printk("%sCall trace:\n", log_lvl);
	147	while (valid_stack_ptr(tinfo, fp)) {
	148	unsigned long new_fp;
	149
	150	lr = (unsigned long )fp;
	151	#ifdef CONFIG_KALLSYMS
	152	printk("%s [<%08lx>] ", log_lvl, lr);
153	#else
154	printk(" [<%08lx>] ", lr);
155	#endif
156	print_symbol("%s\n", lr);
157
158	new_fp = (unsigned long )(fp + 4);
159	if (new_fp <= fp)
160	break;
161	fp = new_fp;
162	}
163	printk("\n");
164	}
165	#else
166	static void show_trace_log_lvl(struct task_struct tsk, unsigned long sp,
167	struct pt_regs regs, const char log_lvl)
168	{
169	unsigned long addr;
170
171	printk("%sCall trace:\n", log_lvl);
172
173	while (!kstack_end(sp)) {
174	addr = *sp++;
175	if (kernel_text_address(addr)) {
176	#ifdef CONFIG_KALLSYMS
177	printk("%s [<%08lx>] ", log_lvl, addr);
178	#else
179	printk(" [<%08lx>] ", addr);
180	#endif
181	print_symbol("%s\n", addr);
182	}
183	}
184	printk("\n");
185	}
186	#endif
187
188	void show_stack_log_lvl(struct task_struct *tsk, unsigned long sp,
189	struct pt_regs regs, const char log_lvl)
190	{
191	struct thread_info *tinfo;
192
193	if (sp == 0) {
194	if (tsk)
195	sp = tsk->thread.cpu_context.ksp;
196	else
197	sp = (unsigned long)&tinfo;
198	}
199	if (!tsk)
200	tsk = current;
201
202	tinfo = task_thread_info(tsk);
203
204	if (valid_stack_ptr(tinfo, sp)) {
205	dump_mem("Stack: ", log_lvl, sp,
206	THREAD_SIZE + (unsigned long)tinfo);
207	show_trace_log_lvl(tsk, (unsigned long *)sp, regs, log_lvl);
208	}
209	}
210
211	void show_stack(struct task_struct tsk, unsigned long stack)
212	{
213	show_stack_log_lvl(tsk, (unsigned long)stack, NULL, "");
214	}
215
216	void dump_stack(void)
217	{
218	unsigned long stack;
219
220	show_trace_log_lvl(current, &stack, NULL, "");
221	}
222	EXPORT_SYMBOL(dump_stack);
223
5f97f7f9 HS	224	static const char *cpu_modes[] = {
	225	"Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
	226	"Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
	227	};
	228
623b0355	229	void show_regs_log_lvl(struct pt_regs regs, const char log_lvl)
5f97f7f9 HS	230	{
	231	unsigned long sp = regs->sp;
	232	unsigned long lr = regs->lr;
	233	unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;
	234
623b0355	235	if (!user_mode(regs)) {
5f97f7f9 HS	236	sp = (unsigned long)regs + FRAME_SIZE_FULL;
5f97f7f9 HS	237
623b0355 HS	238	printk("%s", log_lvl);
	239	print_symbol("PC is at %s\n", instruction_pointer(regs));
	240	printk("%s", log_lvl);
	241	print_symbol("LR is at %s\n", lr);
	242	}
	243
	244	printk("%spc : [<%08lx>] lr : [<%08lx>] %s\n"
	245	"%ssp : %08lx r12: %08lx r11: %08lx\n",
	246	log_lvl, instruction_pointer(regs), lr, print_tainted(),
	247	log_lvl, sp, regs->r12, regs->r11);
	248	printk("%sr10: %08lx r9 : %08lx r8 : %08lx\n",
	249	log_lvl, regs->r10, regs->r9, regs->r8);
	250	printk("%sr7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
	251	log_lvl, regs->r7, regs->r6, regs->r5, regs->r4);
	252	printk("%sr3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
	253	log_lvl, regs->r3, regs->r2, regs->r1, regs->r0);
	254	printk("%sFlags: %c%c%c%c%c\n", log_lvl,
5f97f7f9 HS	255	regs->sr & SR_Q ? 'Q' : 'q',
	256	regs->sr & SR_V ? 'V' : 'v',
	257	regs->sr & SR_N ? 'N' : 'n',
	258	regs->sr & SR_Z ? 'Z' : 'z',
	259	regs->sr & SR_C ? 'C' : 'c');
df679771	260	printk("%sMode bits: %c%c%c%c%c%c%c%c%c%c\n", log_lvl,
5f97f7f9	261	regs->sr & SR_H ? 'H' : 'h',
5f97f7f9	262	regs->sr & SR_J ? 'J' : 'j',
df679771 HS	263	regs->sr & SR_DM ? 'M' : 'm',
df679771 HS	264	regs->sr & SR_D ? 'D' : 'd',
5f97f7f9 HS	265	regs->sr & SR_EM ? 'E' : 'e',
	266	regs->sr & SR_I3M ? '3' : '.',
	267	regs->sr & SR_I2M ? '2' : '.',
	268	regs->sr & SR_I1M ? '1' : '.',
	269	regs->sr & SR_I0M ? '0' : '.',
	270	regs->sr & SR_GM ? 'G' : 'g');
623b0355 HS	271	printk("%sCPU Mode: %s\n", log_lvl, cpu_modes[mode]);
	272	printk("%sProcess: %s [%d] (task: %p thread: %p)\n",
	273	log_lvl, current->comm, current->pid, current,
	274	task_thread_info(current));
	275	}
	276
	277	void show_regs(struct pt_regs *regs)
	278	{
	279	unsigned long sp = regs->sp;
	280
	281	if (!user_mode(regs))
	282	sp = (unsigned long)regs + FRAME_SIZE_FULL;
5f97f7f9	283
623b0355 HS	284	show_regs_log_lvl(regs, "");
623b0355 HS	285	show_trace_log_lvl(current, (unsigned long *)sp, regs, "");
5f97f7f9 HS	286	}
	287	EXPORT_SYMBOL(show_regs);
	288
	289	/* Fill in the fpu structure for a core dump. This is easy -- we don't have any */
	290	int dump_fpu(struct pt_regs regs, elf_fpregset_t fpu)
	291	{
	292	/* Not valid */
	293	return 0;
	294	}
	295
	296	asmlinkage void ret_from_fork(void);
5adc807f AV	297	asmlinkage void ret_from_kernel_thread(void);
5adc807f AV	298	asmlinkage void syscall_return(void);
5f97f7f9	299
6f2c55b8	300	int copy_thread(unsigned long clone_flags, unsigned long usp,
5adc807f	301	unsigned long arg,
5f97f7f9 HS	302	struct task_struct p, struct pt_regs regs)
5f97f7f9 HS	303	{
5adc807f AV	304	struct pt_regs *childregs = task_pt_regs(p);
	305
	306	if (unlikely(!regs)) {
	307	memset(childregs, 0, sizeof(struct pt_regs));
	308	p->thread.cpu_context.r0 = arg;
	309	p->thread.cpu_context.r1 = usp; /* fn */
	310	p->thread.cpu_context.r2 = syscall_return;
	311	p->thread.cpu_context.pc = (unsigned long)ret_from_kernel_thread;
	312	childregs->sr = MODE_SUPERVISOR;
	313	} else {
	314	childregs = regs;
5f97f7f9	315	childregs->sp = usp;
5adc807f AV	316	childregs->r12 = 0; /* Set return value for child */
	317	p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
	318	}
5f97f7f9 HS	319
	320	p->thread.cpu_context.sr = MODE_SUPERVISOR \| SR_GM;
	321	p->thread.cpu_context.ksp = (unsigned long)childregs;
5f97f7f9	322
325d6f55	323	clear_tsk_thread_flag(p, TIF_DEBUG);
13b54a50 HS	324	if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))
	325	ocd_enable(p);
	326
5f97f7f9 HS	327	return 0;
	328	}
	329
	330	/* r12-r8 are dummy parameters to force the compiler to use the stack */
	331	asmlinkage int sys_fork(struct pt_regs *regs)
	332	{
	333	return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
	334	}
	335
	336	asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
992a88b6 HCE	337	void __user parent_tidptr, void __user child_tidptr,
992a88b6 HCE	338	struct pt_regs *regs)
5f97f7f9 HS	339	{
	340	if (!newsp)
	341	newsp = regs->sp;
992a88b6 HCE	342	return do_fork(clone_flags, newsp, regs, 0, parent_tidptr,
992a88b6 HCE	343	child_tidptr);
5f97f7f9 HS	344	}
	345
	346	asmlinkage int sys_vfork(struct pt_regs *regs)
	347	{
	348	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, regs->sp, regs,
	349	0, NULL, NULL);
	350	}
	351
5f97f7f9 HS	352	/*
	353	* This function is supposed to answer the question "who called
	354	* schedule()?"
	355	*/
	356	unsigned long get_wchan(struct task_struct *p)
	357	{
	358	unsigned long pc;
	359	unsigned long stack_page;
	360
	361	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	362	return 0;
	363
c9f4f06d	364	stack_page = (unsigned long)task_stack_page(p);
5f97f7f9 HS	365	BUG_ON(!stack_page);
	366
	367	/*
	368	* The stored value of PC is either the address right after
	369	* the call to __switch_to() or ret_from_fork.
	370	*/
	371	pc = thread_saved_pc(p);
	372	if (in_sched_functions(pc)) {
	373	#ifdef CONFIG_FRAME_POINTER
	374	unsigned long fp = p->thread.cpu_context.r7;
	375	BUG_ON(fp < stack_page \|\| fp > (THREAD_SIZE + stack_page));
	376	pc = (unsigned long )fp;
	377	#else
	378	/*
	379	* We depend on the frame size of schedule here, which
	380	* is actually quite ugly. It might be possible to
	381	* determine the frame size automatically at build
	382	* time by doing this:
	383	* - compile sched.c
	384	* - disassemble the resulting sched.o
	385	* - look for 'sub sp,??' shortly after '<schedule>:'
	386	*/
	387	unsigned long sp = p->thread.cpu_context.ksp + 16;
	388	BUG_ON(sp < stack_page \|\| sp > (THREAD_SIZE + stack_page));
	389	pc = (unsigned long )sp;
	390	#endif
	391	}
	392
	393	return pc;
	394	}