[people/ms/linux.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/cacheflush.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)
{
	/* Disable interrupts first */
	local_irq_disable();
	local_fiq_disable();

	/*
	 * 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);

	/* Clean and invalidate caches */
	flush_cache_all();

	/* Turn off caching */
	cpu_proc_fin();

	/* Push out any further dirty data, and ensure cache is empty */
	flush_cache_all();

	/*
	 * 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.  r4 is the thread argument, r5 is the pointer to
 * the thread function, and r6 points to the exit function.
 */
extern void kernel_thread_helper(void);
asm(	".pushsection .text\n"
"	.align\n"
"	.type	kernel_thread_helper, #function\n"
"kernel_thread_helper:\n"
#ifdef CONFIG_TRACE_IRQFLAGS
"	bl	trace_hardirqs_on\n"
#endif
"	msr	cpsr_c, r7\n"
"	mov	r0, r4\n"
"	mov	lr, r6\n"
"	mov	pc, r5\n"
"	.size	kernel_thread_helper, . - kernel_thread_helper\n"
"	.popsection");

#ifdef CONFIG_ARM_UNWIND
extern void kernel_thread_exit(long code);
asm(	".pushsection .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"
"	.popsection");
#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_r4 = (unsigned long)arg;
	regs.ARM_r5 = (unsigned long)fn;
	regs.ARM_r6 = (unsigned long)kernel_thread_exit;
	regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;
	regs.ARM_pc = (unsigned long)kernel_thread_helper;
	regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT;

	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
9ca03a21	32	#include <asm/cacheflush.h>
1da177e4 LT	33	#include <asm/leds.h>
1da177e4 LT	34	#include <asm/processor.h>
78ff18a4	35	#include <asm/system.h>
d6551e88	36	#include <asm/thread_notify.h>
2d7c11bf	37	#include <asm/stacktrace.h>
2ea83398	38	#include <asm/mach/time.h>
1da177e4	39
ae0a846e RK	40	static const char *processor_modes[] = {
	41	"USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
	42	"UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
	43	"USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
	44	"UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
	45	};
	46
909d6c6c GD	47	static const char *isa_modes[] = {
	48	"ARM" , "Thumb" , "Jazelle", "ThumbEE"
	49	};
	50
1da177e4 LT	51	extern void setup_mm_for_reboot(char mode);
	52
	53	static volatile int hlt_counter;
	54
a09e64fb	55	#include <mach/system.h>
1da177e4 LT	56
	57	void disable_hlt(void)
	58	{
	59	hlt_counter++;
	60	}
	61
	62	EXPORT_SYMBOL(disable_hlt);
	63
	64	void enable_hlt(void)
	65	{
	66	hlt_counter--;
	67	}
	68
	69	EXPORT_SYMBOL(enable_hlt);
	70
	71	static int __init nohlt_setup(char *__unused)
	72	{
	73	hlt_counter = 1;
	74	return 1;
	75	}
	76
	77	static int __init hlt_setup(char *__unused)
	78	{
	79	hlt_counter = 0;
	80	return 1;
	81	}
	82
	83	__setup("nohlt", nohlt_setup);
	84	__setup("hlt", hlt_setup);
	85
be093beb	86	void arm_machine_restart(char mode, const char *cmd)
74617fb6	87	{
9ca03a21 RK	88	/* Disable interrupts first */
	89	local_irq_disable();
	90	local_fiq_disable();
74617fb6 RP	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
9ca03a21 RK	99	/* Clean and invalidate caches */
	100	flush_cache_all();
	101
	102	/* Turn off caching */
	103	cpu_proc_fin();
	104
	105	/* Push out any further dirty data, and ensure cache is empty */
	106	flush_cache_all();
	107
74617fb6 RP	108	/*
	109	* Now call the architecture specific reboot code.
	110	*/
be093beb	111	arch_reset(mode, cmd);
74617fb6 RP	112
	113	/*
	114	* Whoops - the architecture was unable to reboot.
	115	* Tell the user!
	116	*/
	117	mdelay(1000);
	118	printk("Reboot failed -- System halted\n");
	119	while (1);
	120	}
	121
1da177e4	122	/*
74617fb6	123	* Function pointers to optional machine specific functions
1da177e4	124	*/
1da177e4 LT	125	void (*pm_power_off)(void);
	126	EXPORT_SYMBOL(pm_power_off);
	127
be093beb	128	void (arm_pm_restart)(char str, const char cmd) = arm_machine_restart;
74617fb6 RP	129	EXPORT_SYMBOL_GPL(arm_pm_restart);
	130
	131
1da177e4 LT	132	/*
	133	* This is our default idle handler. We need to disable
	134	* interrupts here to ensure we don't miss a wakeup call.
	135	*/
84dff1a7	136	static void default_idle(void)
1da177e4	137	{
9ccdac36 RK	138	if (!need_resched())
	139	arch_idle();
	140	local_irq_enable();
1da177e4 LT	141	}
1da177e4 LT	142
9ccdac36 RK	143	void (*pm_idle)(void) = default_idle;
	144	EXPORT_SYMBOL(pm_idle);
	145
1da177e4	146	/*
9ccdac36 RK	147	* The idle thread, has rather strange semantics for calling pm_idle,
	148	* but this is what x86 does and we need to do the same, so that
	149	* things like cpuidle get called in the same way. The only difference
	150	* is that we always respect 'hlt_counter' to prevent low power idle.
1da177e4 LT	151	*/
	152	void cpu_idle(void)
	153	{
	154	local_fiq_enable();
	155
	156	/* endless idle loop with no priority at all */
	157	while (1) {
9ccdac36 RK	158	tick_nohz_stop_sched_tick(1);
	159	leds_event(led_idle_start);
	160	while (!need_resched()) {
a054a811	161	#ifdef CONFIG_HOTPLUG_CPU
9ccdac36 RK	162	if (cpu_is_offline(smp_processor_id()))
9ccdac36 RK	163	cpu_die();
a054a811 RK	164	#endif
a054a811 RK	165
9ccdac36 RK	166	local_irq_disable();
	167	if (hlt_counter) {
	168	local_irq_enable();
	169	cpu_relax();
	170	} else {
	171	stop_critical_timings();
	172	pm_idle();
	173	start_critical_timings();
	174	/*
	175	* This will eventually be removed - pm_idle
	176	* functions should always return with IRQs
	177	* enabled.
	178	*/
	179	WARN_ON(irqs_disabled());
	180	local_irq_enable();
	181	}
	182	}
1da177e4	183	leds_event(led_idle_end);
9e4559dd	184	tick_nohz_restart_sched_tick();
5bfb5d69	185	preempt_enable_no_resched();
1da177e4	186	schedule();
5bfb5d69	187	preempt_disable();
1da177e4 LT	188	}
	189	}
	190
	191	static char reboot_mode = 'h';
	192
	193	int __init reboot_setup(char *str)
	194	{
	195	reboot_mode = str[0];
	196	return 1;
	197	}
	198
	199	__setup("reboot=", reboot_setup);
	200
	201	void machine_halt(void)
	202	{
	203	}
	204
1da177e4 LT	205
	206	void machine_power_off(void)
	207	{
	208	if (pm_power_off)
	209	pm_power_off();
	210	}
	211
be093beb	212	void machine_restart(char *cmd)
1da177e4	213	{
be093beb	214	arm_pm_restart(reboot_mode, cmd);
1da177e4 LT	215	}
1da177e4 LT	216
652a12ef	217	void __show_regs(struct pt_regs *regs)
1da177e4	218	{
154c772e RK	219	unsigned long flags;
154c772e RK	220	char buf[64];
1da177e4	221
154c772e	222	printk("CPU: %d %s (%s %.*s)\n",
22325525 RV	223	raw_smp_processor_id(), print_tainted(),
22325525 RV	224	init_utsname()->release,
154c772e RK	225	(int)strcspn(init_utsname()->version, " "),
154c772e RK	226	init_utsname()->version);
1da177e4 LT	227	print_symbol("PC is at %s\n", instruction_pointer(regs));
1da177e4 LT	228	print_symbol("LR is at %s\n", regs->ARM_lr);
154c772e	229	printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
1da177e4	230	"sp : %08lx ip : %08lx fp : %08lx\n",
154c772e RK	231	regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
154c772e RK	232	regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
1da177e4 LT	233	printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
	234	regs->ARM_r10, regs->ARM_r9,
	235	regs->ARM_r8);
	236	printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
	237	regs->ARM_r7, regs->ARM_r6,
	238	regs->ARM_r5, regs->ARM_r4);
	239	printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
	240	regs->ARM_r3, regs->ARM_r2,
	241	regs->ARM_r1, regs->ARM_r0);
154c772e RK	242
	243	flags = regs->ARM_cpsr;
	244	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
	245	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
	246	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
	247	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
	248	buf[4] = '\0';
	249
909d6c6c	250	printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
154c772e	251	buf, interrupts_enabled(regs) ? "n" : "ff",
1da177e4 LT	252	fast_interrupts_enabled(regs) ? "n" : "ff",
1da177e4 LT	253	processor_modes[processor_mode(regs)],
909d6c6c	254	isa_modes[isa_mode(regs)],
1da177e4	255	get_fs() == get_ds() ? "kernel" : "user");
154c772e	256	#ifdef CONFIG_CPU_CP15
1da177e4	257	{
f12d0d7c	258	unsigned int ctrl;
154c772e RK	259
154c772e RK	260	buf[0] = '\0';
f12d0d7c	261	#ifdef CONFIG_CPU_CP15_MMU
154c772e RK	262	{
	263	unsigned int transbase, dac;
	264	asm("mrc p15, 0, %0, c2, c0\n\t"
	265	"mrc p15, 0, %1, c3, c0\n"
	266	: "=r" (transbase), "=r" (dac));
	267	snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
	268	transbase, dac);
	269	}
f12d0d7c	270	#endif
154c772e RK	271	asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
	272
	273	printk("Control: %08x%s\n", ctrl, buf);
	274	}
f12d0d7c	275	#endif
1da177e4 LT	276	}
1da177e4 LT	277
652a12ef RK	278	void show_regs(struct pt_regs * regs)
	279	{
	280	printk("\n");
19c5870c	281	printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
652a12ef RK	282	__show_regs(regs);
	283	__backtrace();
	284	}
	285
797245f5 RK	286	ATOMIC_NOTIFIER_HEAD(thread_notify_head);
	287
	288	EXPORT_SYMBOL_GPL(thread_notify_head);
	289
1da177e4 LT	290	/*
	291	* Free current thread data structures etc..
	292	*/
	293	void exit_thread(void)
	294	{
797245f5	295	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
1da177e4 LT	296	}
1da177e4 LT	297
1da177e4 LT	298	void flush_thread(void)
	299	{
	300	struct thread_info *thread = current_thread_info();
	301	struct task_struct *tsk = current;
	302
	303	memset(thread->used_cp, 0, sizeof(thread->used_cp));
	304	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
d6551e88 RK	305	memset(&thread->fpstate, 0, sizeof(union fp_state));
	306
	307	thread_notify(THREAD_NOTIFY_FLUSH, thread);
1da177e4 LT	308	}
	309
	310	void release_thread(struct task_struct *dead_task)
	311	{
1da177e4 LT	312	}
	313
	314	asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
	315
	316	int
6f2c55b8	317	copy_thread(unsigned long clone_flags, unsigned long stack_start,
1da177e4 LT	318	unsigned long stk_sz, struct task_struct p, struct pt_regs regs)
1da177e4 LT	319	{
815d5ec8 AV	320	struct thread_info *thread = task_thread_info(p);
815d5ec8 AV	321	struct pt_regs *childregs = task_pt_regs(p);
1da177e4	322
1da177e4 LT	323	childregs = regs;
	324	childregs->ARM_r0 = 0;
	325	childregs->ARM_sp = stack_start;
	326
	327	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
	328	thread->cpu_context.sp = (unsigned long)childregs;
	329	thread->cpu_context.pc = (unsigned long)ret_from_fork;
	330
	331	if (clone_flags & CLONE_SETTLS)
	332	thread->tp_value = regs->ARM_r3;
	333
	334	return 0;
	335	}
	336
cde3f860 AB	337	/*
	338	* Fill in the task's elfregs structure for a core dump.
	339	*/
	340	int dump_task_regs(struct task_struct t, elf_gregset_t elfregs)
	341	{
	342	elf_core_copy_regs(elfregs, task_pt_regs(t));
	343	return 1;
	344	}
	345
1da177e4 LT	346	/*
	347	* fill in the fpe structure for a core dump...
	348	*/
	349	int dump_fpu (struct pt_regs regs, struct user_fp fp)
	350	{
	351	struct thread_info *thread = current_thread_info();
	352	int used_math = thread->used_cp[1] \| thread->used_cp[2];
	353
	354	if (used_math)
	355	memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
	356
	357	return used_math != 0;
	358	}
	359	EXPORT_SYMBOL(dump_fpu);
	360
1da177e4 LT	361	/*
1da177e4 LT	362	* Shuffle the argument into the correct register before calling the
ac78884e RK	363	* thread function. r4 is the thread argument, r5 is the pointer to
ac78884e RK	364	* the thread function, and r6 points to the exit function.
1da177e4 LT	365	*/
1da177e4 LT	366	extern void kernel_thread_helper(void);
4260415f	367	asm( ".pushsection .text\n"
1da177e4 LT	368	" .align\n"
	369	" .type kernel_thread_helper, #function\n"
	370	"kernel_thread_helper:\n"
ac78884e RK	371	#ifdef CONFIG_TRACE_IRQFLAGS
	372	" bl trace_hardirqs_on\n"
	373	#endif
	374	" msr cpsr_c, r7\n"
	375	" mov r0, r4\n"
	376	" mov lr, r6\n"
	377	" mov pc, r5\n"
1da177e4	378	" .size kernel_thread_helper, . - kernel_thread_helper\n"
4260415f	379	" .popsection");
1da177e4	380
feb97c36 CM	381	#ifdef CONFIG_ARM_UNWIND
feb97c36 CM	382	extern void kernel_thread_exit(long code);
4260415f	383	asm( ".pushsection .text\n"
feb97c36 CM	384	" .align\n"
	385	" .type kernel_thread_exit, #function\n"
	386	"kernel_thread_exit:\n"
	387	" .fnstart\n"
	388	" .cantunwind\n"
	389	" bl do_exit\n"
	390	" nop\n"
	391	" .fnend\n"
	392	" .size kernel_thread_exit, . - kernel_thread_exit\n"
4260415f	393	" .popsection");
feb97c36 CM	394	#else
	395	#define kernel_thread_exit do_exit
	396	#endif
	397
1da177e4 LT	398	/*
	399	* Create a kernel thread.
	400	*/
	401	pid_t kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
	402	{
	403	struct pt_regs regs;
	404
	405	memset(&regs, 0, sizeof(regs));
	406
ac78884e RK	407	regs.ARM_r4 = (unsigned long)arg;
	408	regs.ARM_r5 = (unsigned long)fn;
	409	regs.ARM_r6 = (unsigned long)kernel_thread_exit;
	410	regs.ARM_r7 = SVC_MODE \| PSR_ENDSTATE \| PSR_ISETSTATE;
1da177e4	411	regs.ARM_pc = (unsigned long)kernel_thread_helper;
ac78884e	412	regs.ARM_cpsr = regs.ARM_r7 \| PSR_I_BIT;
1da177e4 LT	413
	414	return do_fork(flags\|CLONE_VM\|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
	415	}
	416	EXPORT_SYMBOL(kernel_thread);
	417
	418	unsigned long get_wchan(struct task_struct *p)
	419	{
2d7c11bf	420	struct stackframe frame;
1da177e4 LT	421	int count = 0;
	422	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	423	return 0;
	424
2d7c11bf CM	425	frame.fp = thread_saved_fp(p);
	426	frame.sp = thread_saved_sp(p);
	427	frame.lr = 0; /* recovered from the stack */
	428	frame.pc = thread_saved_pc(p);
1da177e4	429	do {
2d7c11bf CM	430	int ret = unwind_frame(&frame);
2d7c11bf CM	431	if (ret < 0)
1da177e4	432	return 0;
2d7c11bf CM	433	if (!in_sched_functions(frame.pc))
2d7c11bf CM	434	return frame.pc;
1da177e4 LT	435	} while (count ++ < 16);
	436	return 0;
	437	}