[net-next-2.6.git] / arch / arm / kernel / process.c

/*
 *  linux/arch/arm/kernel/process.c
 *
 *  Copyright (C) 1996-2000 Russell King - Converted to ARM.
 *  Original Copyright (C) 1995  Linus Torvalds
 *
 * 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 <stdarg.h>

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/user.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <linux/kallsyms.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/elfcore.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/utsname.h>
#include <linux/uaccess.h>

#include <asm/leds.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/thread_notify.h>
#include <asm/stacktrace.h>
#include <asm/mach/time.h>

static const char *processor_modes[] = {
  "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
  "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
  "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
  "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
};

static const char *isa_modes[] = {
  "ARM" , "Thumb" , "Jazelle", "ThumbEE"
};

extern void setup_mm_for_reboot(char mode);

static volatile int hlt_counter;

#include <mach/system.h>

void disable_hlt(void)
{
	hlt_counter++;
}

EXPORT_SYMBOL(disable_hlt);

void enable_hlt(void)
{
	hlt_counter--;
}

EXPORT_SYMBOL(enable_hlt);

static int __init nohlt_setup(char *__unused)
{
	hlt_counter = 1;
	return 1;
}

static int __init hlt_setup(char *__unused)
{
	hlt_counter = 0;
	return 1;
}

__setup("nohlt", nohlt_setup);
__setup("hlt", hlt_setup);

void arm_machine_restart(char mode, const char *cmd)
{
	/*
	 * Clean and disable cache, and turn off interrupts
	 */
	cpu_proc_fin();

	/*
	 * Tell the mm system that we are going to reboot -
	 * we may need it to insert some 1:1 mappings so that
	 * soft boot works.
	 */
	setup_mm_for_reboot(mode);

	/*
	 * Now call the architecture specific reboot code.
	 */
	arch_reset(mode, cmd);

	/*
	 * Whoops - the architecture was unable to reboot.
	 * Tell the user!
	 */
	mdelay(1000);
	printk("Reboot failed -- System halted\n");
	while (1);
}

/*
 * Function pointers to optional machine specific functions
 */
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);

void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;
EXPORT_SYMBOL_GPL(arm_pm_restart);


/*
 * This is our default idle handler.  We need to disable
 * interrupts here to ensure we don't miss a wakeup call.
 */
static void default_idle(void)
{
	if (!need_resched())
		arch_idle();
	local_irq_enable();
}

void (*pm_idle)(void) = default_idle;
EXPORT_SYMBOL(pm_idle);

/*
 * The idle thread, has rather strange semantics for calling pm_idle,
 * but this is what x86 does and we need to do the same, so that
 * things like cpuidle get called in the same way.  The only difference
 * is that we always respect 'hlt_counter' to prevent low power idle.
 */
void cpu_idle(void)
{
	local_fiq_enable();

	/* endless idle loop with no priority at all */
	while (1) {
		tick_nohz_stop_sched_tick(1);
		leds_event(led_idle_start);
		while (!need_resched()) {
#ifdef CONFIG_HOTPLUG_CPU
			if (cpu_is_offline(smp_processor_id()))
				cpu_die();
#endif

			local_irq_disable();
			if (hlt_counter) {
				local_irq_enable();
				cpu_relax();
			} else {
				stop_critical_timings();
				pm_idle();
				start_critical_timings();
				/*
				 * This will eventually be removed - pm_idle
				 * functions should always return with IRQs
				 * enabled.
				 */
				WARN_ON(irqs_disabled());
				local_irq_enable();
			}
		}
		leds_event(led_idle_end);
		tick_nohz_restart_sched_tick();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}

static char reboot_mode = 'h';

int __init reboot_setup(char *str)
{
	reboot_mode = str[0];
	return 1;
}

__setup("reboot=", reboot_setup);

void machine_halt(void)
{
}


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

void machine_restart(char *cmd)
{
	arm_pm_restart(reboot_mode, cmd);
}

void __show_regs(struct pt_regs *regs)
{
	unsigned long flags;
	char buf[64];

	printk("CPU: %d    %s  (%s %.*s)\n",
		raw_smp_processor_id(), print_tainted(),
		init_utsname()->release,
		(int)strcspn(init_utsname()->version, " "),
		init_utsname()->version);
	print_symbol("PC is at %s\n", instruction_pointer(regs));
	print_symbol("LR is at %s\n", regs->ARM_lr);
	printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"
	       "sp : %08lx  ip : %08lx  fp : %08lx\n",
		regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
		regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
	printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
		regs->ARM_r10, regs->ARM_r9,
		regs->ARM_r8);
	printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
		regs->ARM_r7, regs->ARM_r6,
		regs->ARM_r5, regs->ARM_r4);
	printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
		regs->ARM_r3, regs->ARM_r2,
		regs->ARM_r1, regs->ARM_r0);

	flags = regs->ARM_cpsr;
	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
	buf[4] = '\0';

	printk("Flags: %s  IRQs o%s  FIQs o%s  Mode %s  ISA %s  Segment %s\n",
		buf, interrupts_enabled(regs) ? "n" : "ff",
		fast_interrupts_enabled(regs) ? "n" : "ff",
		processor_modes[processor_mode(regs)],
		isa_modes[isa_mode(regs)],
		get_fs() == get_ds() ? "kernel" : "user");
#ifdef CONFIG_CPU_CP15
	{
		unsigned int ctrl;

		buf[0] = '\0';
#ifdef CONFIG_CPU_CP15_MMU
		{
			unsigned int transbase, dac;
			asm("mrc p15, 0, %0, c2, c0\n\t"
			    "mrc p15, 0, %1, c3, c0\n"
			    : "=r" (transbase), "=r" (dac));
			snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",
			  	transbase, dac);
		}
#endif
		asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));

		printk("Control: %08x%s\n", ctrl, buf);
	}
#endif
}

void show_regs(struct pt_regs * regs)
{
	printk("\n");
	printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
	__show_regs(regs);
	__backtrace();
}

ATOMIC_NOTIFIER_HEAD(thread_notify_head);

EXPORT_SYMBOL_GPL(thread_notify_head);

/*
 * Free current thread data structures etc..
 */
void exit_thread(void)
{
	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
}

void flush_thread(void)
{
	struct thread_info *thread = current_thread_info();
	struct task_struct *tsk = current;

	memset(thread->used_cp, 0, sizeof(thread->used_cp));
	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
	memset(&thread->fpstate, 0, sizeof(union fp_state));

	thread_notify(THREAD_NOTIFY_FLUSH, thread);
}

void release_thread(struct task_struct *dead_task)
{
}

asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");

int
copy_thread(unsigned long clone_flags, unsigned long stack_start,
	    unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
{
	struct thread_info *thread = task_thread_info(p);
	struct pt_regs *childregs = task_pt_regs(p);

	*childregs = *regs;
	childregs->ARM_r0 = 0;
	childregs->ARM_sp = stack_start;

	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
	thread->cpu_context.sp = (unsigned long)childregs;
	thread->cpu_context.pc = (unsigned long)ret_from_fork;

	if (clone_flags & CLONE_SETTLS)
		thread->tp_value = regs->ARM_r3;

	return 0;
}

/*
 * Fill in the task's elfregs structure for a core dump.
 */
int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
{
	elf_core_copy_regs(elfregs, task_pt_regs(t));
	return 1;
}

/*
 * fill in the fpe structure for a core dump...
 */
int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
{
	struct thread_info *thread = current_thread_info();
	int used_math = thread->used_cp[1] | thread->used_cp[2];

	if (used_math)
		memcpy(fp, &thread->fpstate.soft, sizeof (*fp));

	return used_math != 0;
}
EXPORT_SYMBOL(dump_fpu);

/*
 * Shuffle the argument into the correct register before calling the
 * thread function.  r1 is the thread argument, r2 is the pointer to
 * the thread function, and r3 points to the exit function.
 */
extern void kernel_thread_helper(void);
asm(	".section .text\n"
"	.align\n"
"	.type	kernel_thread_helper, #function\n"
"kernel_thread_helper:\n"
"	mov	r0, r1\n"
"	mov	lr, r3\n"
"	mov	pc, r2\n"
"	.size	kernel_thread_helper, . - kernel_thread_helper\n"
"	.previous");

#ifdef CONFIG_ARM_UNWIND
extern void kernel_thread_exit(long code);
asm(	".section .text\n"
"	.align\n"
"	.type	kernel_thread_exit, #function\n"
"kernel_thread_exit:\n"
"	.fnstart\n"
"	.cantunwind\n"
"	bl	do_exit\n"
"	nop\n"
"	.fnend\n"
"	.size	kernel_thread_exit, . - kernel_thread_exit\n"
"	.previous");
#else
#define kernel_thread_exit	do_exit
#endif

/*
 * Create a kernel thread.
 */
pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
	struct pt_regs regs;

	memset(&regs, 0, sizeof(regs));

	regs.ARM_r1 = (unsigned long)arg;
	regs.ARM_r2 = (unsigned long)fn;
	regs.ARM_r3 = (unsigned long)kernel_thread_exit;
	regs.ARM_pc = (unsigned long)kernel_thread_helper;
	regs.ARM_cpsr = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;

	return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);

unsigned long get_wchan(struct task_struct *p)
{
	struct stackframe frame;
	int count = 0;
	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	frame.fp = thread_saved_fp(p);
	frame.sp = thread_saved_sp(p);
	frame.lr = 0;			/* recovered from the stack */
	frame.pc = thread_saved_pc(p);
	do {
		int ret = unwind_frame(&frame);
		if (ret < 0)
			return 0;
		if (!in_sched_functions(frame.pc))
			return frame.pc;
	} while (count ++ < 16);
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/arm/kernel/process.c
	3	*
	4	* Copyright (C) 1996-2000 Russell King - Converted to ARM.
	5	* Original Copyright (C) 1995 Linus Torvalds
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11	#include <stdarg.h>
	12
1da177e4 LT	13	#include <linux/module.h>
	14	#include <linux/sched.h>
	15	#include <linux/kernel.h>
	16	#include <linux/mm.h>
	17	#include <linux/stddef.h>
	18	#include <linux/unistd.h>
1da177e4	19	#include <linux/user.h>
1da177e4 LT	20	#include <linux/delay.h>
	21	#include <linux/reboot.h>
	22	#include <linux/interrupt.h>
	23	#include <linux/kallsyms.h>
	24	#include <linux/init.h>
a054a811	25	#include <linux/cpu.h>
84dff1a7	26	#include <linux/elfcore.h>
74617fb6	27	#include <linux/pm.h>
9e4559dd	28	#include <linux/tick.h>
154c772e	29	#include <linux/utsname.h>
33fa9b13	30	#include <linux/uaccess.h>
1da177e4	31
1da177e4 LT	32	#include <asm/leds.h>
1da177e4 LT	33	#include <asm/processor.h>
78ff18a4	34	#include <asm/system.h>
d6551e88	35	#include <asm/thread_notify.h>
2d7c11bf	36	#include <asm/stacktrace.h>
2ea83398	37	#include <asm/mach/time.h>
1da177e4	38
ae0a846e RK	39	static const char *processor_modes[] = {
	40	"USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
	41	"UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
	42	"USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
	43	"UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
	44	};
	45
909d6c6c GD	46	static const char *isa_modes[] = {
	47	"ARM" , "Thumb" , "Jazelle", "ThumbEE"
	48	};
	49
1da177e4 LT	50	extern void setup_mm_for_reboot(char mode);
	51
	52	static volatile int hlt_counter;
	53
a09e64fb	54	#include <mach/system.h>
1da177e4 LT	55
	56	void disable_hlt(void)
	57	{
	58	hlt_counter++;
	59	}
	60
	61	EXPORT_SYMBOL(disable_hlt);
	62
	63	void enable_hlt(void)
	64	{
	65	hlt_counter--;
	66	}
	67
	68	EXPORT_SYMBOL(enable_hlt);
	69
	70	static int __init nohlt_setup(char *__unused)
	71	{
	72	hlt_counter = 1;
	73	return 1;
	74	}
	75
	76	static int __init hlt_setup(char *__unused)
	77	{
	78	hlt_counter = 0;
	79	return 1;
	80	}
	81
	82	__setup("nohlt", nohlt_setup);
	83	__setup("hlt", hlt_setup);
	84
be093beb	85	void arm_machine_restart(char mode, const char *cmd)
74617fb6 RP	86	{
	87	/*
	88	* Clean and disable cache, and turn off interrupts
	89	*/
	90	cpu_proc_fin();
	91
	92	/*
	93	* Tell the mm system that we are going to reboot -
	94	* we may need it to insert some 1:1 mappings so that
	95	* soft boot works.
	96	*/
	97	setup_mm_for_reboot(mode);
	98
	99	/*
	100	* Now call the architecture specific reboot code.
	101	*/
be093beb	102	arch_reset(mode, cmd);
74617fb6 RP	103
	104	/*
	105	* Whoops - the architecture was unable to reboot.
	106	* Tell the user!
	107	*/
	108	mdelay(1000);
	109	printk("Reboot failed -- System halted\n");
	110	while (1);
	111	}
	112
1da177e4	113	/*
74617fb6	114	* Function pointers to optional machine specific functions
1da177e4	115	*/
1da177e4 LT	116	void (*pm_power_off)(void);
	117	EXPORT_SYMBOL(pm_power_off);
	118
be093beb	119	void (arm_pm_restart)(char str, const char cmd) = arm_machine_restart;
74617fb6 RP	120	EXPORT_SYMBOL_GPL(arm_pm_restart);
	121
	122
1da177e4 LT	123	/*
	124	* This is our default idle handler. We need to disable
	125	* interrupts here to ensure we don't miss a wakeup call.
	126	*/
84dff1a7	127	static void default_idle(void)
1da177e4	128	{
9ccdac36 RK	129	if (!need_resched())
	130	arch_idle();
	131	local_irq_enable();
1da177e4 LT	132	}
1da177e4 LT	133
9ccdac36 RK	134	void (*pm_idle)(void) = default_idle;
	135	EXPORT_SYMBOL(pm_idle);
	136
1da177e4	137	/*
9ccdac36 RK	138	* The idle thread, has rather strange semantics for calling pm_idle,
	139	* but this is what x86 does and we need to do the same, so that
	140	* things like cpuidle get called in the same way. The only difference
	141	* is that we always respect 'hlt_counter' to prevent low power idle.
1da177e4 LT	142	*/
	143	void cpu_idle(void)
	144	{
	145	local_fiq_enable();
	146
	147	/* endless idle loop with no priority at all */
	148	while (1) {
9ccdac36 RK	149	tick_nohz_stop_sched_tick(1);
	150	leds_event(led_idle_start);
	151	while (!need_resched()) {
a054a811	152	#ifdef CONFIG_HOTPLUG_CPU
9ccdac36 RK	153	if (cpu_is_offline(smp_processor_id()))
9ccdac36 RK	154	cpu_die();
a054a811 RK	155	#endif
a054a811 RK	156
9ccdac36 RK	157	local_irq_disable();
	158	if (hlt_counter) {
	159	local_irq_enable();
	160	cpu_relax();
	161	} else {
	162	stop_critical_timings();
	163	pm_idle();
	164	start_critical_timings();
	165	/*
	166	* This will eventually be removed - pm_idle
	167	* functions should always return with IRQs
	168	* enabled.
	169	*/
	170	WARN_ON(irqs_disabled());
	171	local_irq_enable();
	172	}
	173	}
1da177e4	174	leds_event(led_idle_end);
9e4559dd	175	tick_nohz_restart_sched_tick();
5bfb5d69	176	preempt_enable_no_resched();
1da177e4	177	schedule();
5bfb5d69	178	preempt_disable();
1da177e4 LT	179	}
	180	}
	181
	182	static char reboot_mode = 'h';
	183
	184	int __init reboot_setup(char *str)
	185	{
	186	reboot_mode = str[0];
	187	return 1;
	188	}
	189
	190	__setup("reboot=", reboot_setup);
	191
	192	void machine_halt(void)
	193	{
	194	}
	195
1da177e4 LT	196
	197	void machine_power_off(void)
	198	{
	199	if (pm_power_off)
	200	pm_power_off();
	201	}
	202
be093beb	203	void machine_restart(char *cmd)
1da177e4	204	{
be093beb	205	arm_pm_restart(reboot_mode, cmd);
1da177e4 LT	206	}
1da177e4 LT	207
652a12ef	208	void __show_regs(struct pt_regs *regs)
1da177e4	209	{
154c772e RK	210	unsigned long flags;
154c772e RK	211	char buf[64];
1da177e4	212
154c772e	213	printk("CPU: %d %s (%s %.*s)\n",
22325525 RV	214	raw_smp_processor_id(), print_tainted(),
22325525 RV	215	init_utsname()->release,
154c772e RK	216	(int)strcspn(init_utsname()->version, " "),
154c772e RK	217	init_utsname()->version);
1da177e4 LT	218	print_symbol("PC is at %s\n", instruction_pointer(regs));
1da177e4 LT	219	print_symbol("LR is at %s\n", regs->ARM_lr);
154c772e	220	printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
1da177e4	221	"sp : %08lx ip : %08lx fp : %08lx\n",
154c772e RK	222	regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
154c772e RK	223	regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
1da177e4 LT	224	printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
	225	regs->ARM_r10, regs->ARM_r9,
	226	regs->ARM_r8);
	227	printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
	228	regs->ARM_r7, regs->ARM_r6,
	229	regs->ARM_r5, regs->ARM_r4);
	230	printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
	231	regs->ARM_r3, regs->ARM_r2,
	232	regs->ARM_r1, regs->ARM_r0);
154c772e RK	233
	234	flags = regs->ARM_cpsr;
	235	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
	236	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
	237	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
	238	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
	239	buf[4] = '\0';
	240
909d6c6c	241	printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
154c772e	242	buf, interrupts_enabled(regs) ? "n" : "ff",
1da177e4 LT	243	fast_interrupts_enabled(regs) ? "n" : "ff",
1da177e4 LT	244	processor_modes[processor_mode(regs)],
909d6c6c	245	isa_modes[isa_mode(regs)],
1da177e4	246	get_fs() == get_ds() ? "kernel" : "user");
154c772e	247	#ifdef CONFIG_CPU_CP15
1da177e4	248	{
f12d0d7c	249	unsigned int ctrl;
154c772e RK	250
154c772e RK	251	buf[0] = '\0';
f12d0d7c	252	#ifdef CONFIG_CPU_CP15_MMU
154c772e RK	253	{
	254	unsigned int transbase, dac;
	255	asm("mrc p15, 0, %0, c2, c0\n\t"
	256	"mrc p15, 0, %1, c3, c0\n"
	257	: "=r" (transbase), "=r" (dac));
	258	snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
	259	transbase, dac);
	260	}
f12d0d7c	261	#endif
154c772e RK	262	asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
	263
	264	printk("Control: %08x%s\n", ctrl, buf);
	265	}
f12d0d7c	266	#endif
1da177e4 LT	267	}
1da177e4 LT	268
652a12ef RK	269	void show_regs(struct pt_regs * regs)
	270	{
	271	printk("\n");
19c5870c	272	printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
652a12ef RK	273	__show_regs(regs);
	274	__backtrace();
	275	}
	276
797245f5 RK	277	ATOMIC_NOTIFIER_HEAD(thread_notify_head);
	278
	279	EXPORT_SYMBOL_GPL(thread_notify_head);
	280
1da177e4 LT	281	/*
	282	* Free current thread data structures etc..
	283	*/
	284	void exit_thread(void)
	285	{
797245f5	286	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
1da177e4 LT	287	}
1da177e4 LT	288
1da177e4 LT	289	void flush_thread(void)
	290	{
	291	struct thread_info *thread = current_thread_info();
	292	struct task_struct *tsk = current;
	293
	294	memset(thread->used_cp, 0, sizeof(thread->used_cp));
	295	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
d6551e88 RK	296	memset(&thread->fpstate, 0, sizeof(union fp_state));
	297
	298	thread_notify(THREAD_NOTIFY_FLUSH, thread);
1da177e4 LT	299	}
	300
	301	void release_thread(struct task_struct *dead_task)
	302	{
1da177e4 LT	303	}
	304
	305	asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
	306
	307	int
6f2c55b8	308	copy_thread(unsigned long clone_flags, unsigned long stack_start,
1da177e4 LT	309	unsigned long stk_sz, struct task_struct p, struct pt_regs regs)
1da177e4 LT	310	{
815d5ec8 AV	311	struct thread_info *thread = task_thread_info(p);
815d5ec8 AV	312	struct pt_regs *childregs = task_pt_regs(p);
1da177e4	313
1da177e4 LT	314	childregs = regs;
	315	childregs->ARM_r0 = 0;
	316	childregs->ARM_sp = stack_start;
	317
	318	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
	319	thread->cpu_context.sp = (unsigned long)childregs;
	320	thread->cpu_context.pc = (unsigned long)ret_from_fork;
	321
	322	if (clone_flags & CLONE_SETTLS)
	323	thread->tp_value = regs->ARM_r3;
	324
	325	return 0;
	326	}
	327
cde3f860 AB	328	/*
	329	* Fill in the task's elfregs structure for a core dump.
	330	*/
	331	int dump_task_regs(struct task_struct t, elf_gregset_t elfregs)
	332	{
	333	elf_core_copy_regs(elfregs, task_pt_regs(t));
	334	return 1;
	335	}
	336
1da177e4 LT	337	/*
	338	* fill in the fpe structure for a core dump...
	339	*/
	340	int dump_fpu (struct pt_regs regs, struct user_fp fp)
	341	{
	342	struct thread_info *thread = current_thread_info();
	343	int used_math = thread->used_cp[1] \| thread->used_cp[2];
	344
	345	if (used_math)
	346	memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
	347
	348	return used_math != 0;
	349	}
	350	EXPORT_SYMBOL(dump_fpu);
	351
1da177e4 LT	352	/*
	353	* Shuffle the argument into the correct register before calling the
	354	* thread function. r1 is the thread argument, r2 is the pointer to
	355	* the thread function, and r3 points to the exit function.
	356	*/
	357	extern void kernel_thread_helper(void);
	358	asm( ".section .text\n"
	359	" .align\n"
	360	" .type kernel_thread_helper, #function\n"
	361	"kernel_thread_helper:\n"
	362	" mov r0, r1\n"
	363	" mov lr, r3\n"
	364	" mov pc, r2\n"
	365	" .size kernel_thread_helper, . - kernel_thread_helper\n"
	366	" .previous");
	367
feb97c36 CM	368	#ifdef CONFIG_ARM_UNWIND
	369	extern void kernel_thread_exit(long code);
	370	asm( ".section .text\n"
	371	" .align\n"
	372	" .type kernel_thread_exit, #function\n"
	373	"kernel_thread_exit:\n"
	374	" .fnstart\n"
	375	" .cantunwind\n"
	376	" bl do_exit\n"
	377	" nop\n"
	378	" .fnend\n"
	379	" .size kernel_thread_exit, . - kernel_thread_exit\n"
	380	" .previous");
	381	#else
	382	#define kernel_thread_exit do_exit
	383	#endif
	384
1da177e4 LT	385	/*
	386	* Create a kernel thread.
	387	*/
	388	pid_t kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
	389	{
	390	struct pt_regs regs;
	391
	392	memset(&regs, 0, sizeof(regs));
	393
	394	regs.ARM_r1 = (unsigned long)arg;
	395	regs.ARM_r2 = (unsigned long)fn;
feb97c36	396	regs.ARM_r3 = (unsigned long)kernel_thread_exit;
1da177e4	397	regs.ARM_pc = (unsigned long)kernel_thread_helper;
b86040a5	398	regs.ARM_cpsr = SVC_MODE \| PSR_ENDSTATE \| PSR_ISETSTATE;
1da177e4 LT	399
	400	return do_fork(flags\|CLONE_VM\|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
	401	}
	402	EXPORT_SYMBOL(kernel_thread);
	403
	404	unsigned long get_wchan(struct task_struct *p)
	405	{
2d7c11bf	406	struct stackframe frame;
1da177e4 LT	407	int count = 0;
	408	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	409	return 0;
	410
2d7c11bf CM	411	frame.fp = thread_saved_fp(p);
	412	frame.sp = thread_saved_sp(p);
	413	frame.lr = 0; /* recovered from the stack */
	414	frame.pc = thread_saved_pc(p);
1da177e4	415	do {
2d7c11bf CM	416	int ret = unwind_frame(&frame);
2d7c11bf CM	417	if (ret < 0)
1da177e4	418	return 0;
2d7c11bf CM	419	if (!in_sched_functions(frame.pc))
2d7c11bf CM	420	return frame.pc;
1da177e4 LT	421	} while (count ++ < 16);
	422	return 0;
	423	}