[deliverable/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/export.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 <linux/random.h>
#include <linux/hw_breakpoint.h>
#include <linux/cpuidle.h>

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

#ifdef CONFIG_CC_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif

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(void);

static volatile int hlt_counter;

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);

extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
typedef void (*phys_reset_t)(unsigned long);

/*
 * A temporary stack to use for CPU reset. This is static so that we
 * don't clobber it with the identity mapping. When running with this
 * stack, any references to the current task *will not work* so you
 * should really do as little as possible before jumping to your reset
 * code.
 */
static u64 soft_restart_stack[16];

static void __soft_restart(void *addr)
{
	phys_reset_t phys_reset;

	/* Take out a flat memory mapping. */
	setup_mm_for_reboot();

	/* 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();

	/* Switch to the identity mapping. */
	phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
	phys_reset((unsigned long)addr);

	/* Should never get here. */
	BUG();
}

void soft_restart(unsigned long addr)
{
	u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);

	/* Disable interrupts first */
	local_irq_disable();
	local_fiq_disable();

	/* Disable the L2 if we're the last man standing. */
	if (num_online_cpus() == 1)
		outer_disable();

	/* Change to the new stack and continue with the reset. */
	call_with_stack(__soft_restart, (void *)addr, (void *)stack);

	/* Should never get here. */
	BUG();
}

static void null_restart(char mode, const char *cmd)
{
}

/*
 * 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) = null_restart;
EXPORT_SYMBOL_GPL(arm_pm_restart);

/*
 * This is our default idle handler.
 */

void (*arm_pm_idle)(void);

static void default_idle(void)
{
	if (arm_pm_idle)
		arm_pm_idle();
	else
		cpu_do_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_idle_enter();
		rcu_idle_enter();
		leds_event(led_idle_start);
		while (!need_resched()) {
#ifdef CONFIG_HOTPLUG_CPU
			if (cpu_is_offline(smp_processor_id()))
				cpu_die();
#endif

			/*
			 * We need to disable interrupts here
			 * to ensure we don't miss a wakeup call.
			 */
			local_irq_disable();
#ifdef CONFIG_PL310_ERRATA_769419
			wmb();
#endif
			if (hlt_counter) {
				local_irq_enable();
				cpu_relax();
			} else if (!need_resched()) {
				stop_critical_timings();
				if (cpuidle_idle_call())
					pm_idle();
				start_critical_timings();
				/*
				 * pm_idle functions must always
				 * return with IRQs enabled.
				 */
				WARN_ON(irqs_disabled());
			} else
				local_irq_enable();
		}
		leds_event(led_idle_end);
		rcu_idle_exit();
		tick_nohz_idle_exit();
		schedule_preempt_disabled();
	}
}

static char reboot_mode = 'h';

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

__setup("reboot=", reboot_setup);

void machine_shutdown(void)
{
#ifdef CONFIG_SMP
	smp_send_stop();
#endif
}

void machine_halt(void)
{
	machine_shutdown();
	while (1);
}

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

void machine_restart(char *cmd)
{
	machine_shutdown();

	arm_pm_restart(reboot_mode, cmd);

	/* Give a grace period for failure to restart of 1s */
	mdelay(1000);

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

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);
	dump_stack();
}

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;

	flush_ptrace_hw_breakpoint(tsk);

	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;

	clear_ptrace_hw_breakpoint(p);

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

	thread_notify(THREAD_NOTIFY_COPY, thread);

	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;
}

unsigned long arch_randomize_brk(struct mm_struct *mm)
{
	unsigned long range_end = mm->brk + 0x02000000;
	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
}

#ifdef CONFIG_MMU
/*
 * The vectors page is always readable from user space for the
 * atomic helpers and the signal restart code. Insert it into the
 * gate_vma so that it is visible through ptrace and /proc/<pid>/mem.
 */
static struct vm_area_struct gate_vma;

static int __init gate_vma_init(void)
{
	gate_vma.vm_start	= 0xffff0000;
	gate_vma.vm_end		= 0xffff0000 + PAGE_SIZE;
	gate_vma.vm_page_prot	= PAGE_READONLY_EXEC;
	gate_vma.vm_flags	= VM_READ | VM_EXEC |
				  VM_MAYREAD | VM_MAYEXEC;
	return 0;
}
arch_initcall(gate_vma_init);

struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
	return &gate_vma;
}

int in_gate_area(struct mm_struct *mm, unsigned long addr)
{
	return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
}

int in_gate_area_no_mm(unsigned long addr)
{
	return in_gate_area(NULL, addr);
}

const char *arch_vma_name(struct vm_area_struct *vma)
{
	return (vma == &gate_vma) ? "[vectors]" : NULL;
}
#endif
Commit	Line	Data
	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
	13	#include <linux/export.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>
	19	#include <linux/user.h>
	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>
	25	#include <linux/cpu.h>
	26	#include <linux/elfcore.h>
	27	#include <linux/pm.h>
	28	#include <linux/tick.h>
	29	#include <linux/utsname.h>
	30	#include <linux/uaccess.h>
	31	#include <linux/random.h>
	32	#include <linux/hw_breakpoint.h>
	33	#include <linux/cpuidle.h>
	34
	35	#include <asm/cacheflush.h>
	36	#include <asm/leds.h>
	37	#include <asm/processor.h>
	38	#include <asm/thread_notify.h>
	39	#include <asm/stacktrace.h>
	40	#include <asm/mach/time.h>
	41
	42	#ifdef CONFIG_CC_STACKPROTECTOR
	43	#include <linux/stackprotector.h>
	44	unsigned long __stack_chk_guard __read_mostly;
	45	EXPORT_SYMBOL(__stack_chk_guard);
	46	#endif
	47
	48	static const char *processor_modes[] = {
	49	"USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
	50	"UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
	51	"USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
	52	"UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
	53	};
	54
	55	static const char *isa_modes[] = {
	56	"ARM" , "Thumb" , "Jazelle", "ThumbEE"
	57	};
	58
	59	extern void setup_mm_for_reboot(void);
	60
	61	static volatile int hlt_counter;
	62
	63	void disable_hlt(void)
	64	{
	65	hlt_counter++;
	66	}
	67
	68	EXPORT_SYMBOL(disable_hlt);
	69
	70	void enable_hlt(void)
	71	{
	72	hlt_counter--;
	73	}
	74
	75	EXPORT_SYMBOL(enable_hlt);
	76
	77	static int __init nohlt_setup(char *__unused)
	78	{
	79	hlt_counter = 1;
	80	return 1;
	81	}
	82
	83	static int __init hlt_setup(char *__unused)
	84	{
	85	hlt_counter = 0;
	86	return 1;
	87	}
	88
	89	__setup("nohlt", nohlt_setup);
	90	__setup("hlt", hlt_setup);
	91
	92	extern void call_with_stack(void (fn)(void ), void arg, void sp);
	93	typedef void (*phys_reset_t)(unsigned long);
	94
	95	/*
	96	* A temporary stack to use for CPU reset. This is static so that we
	97	* don't clobber it with the identity mapping. When running with this
	98	* stack, any references to the current task will not work so you
	99	* should really do as little as possible before jumping to your reset
	100	* code.
	101	*/
	102	static u64 soft_restart_stack[16];
	103
	104	static void __soft_restart(void *addr)
	105	{
	106	phys_reset_t phys_reset;
	107
	108	/* Take out a flat memory mapping. */
	109	setup_mm_for_reboot();
	110
	111	/* Clean and invalidate caches */
	112	flush_cache_all();
	113
	114	/* Turn off caching */
	115	cpu_proc_fin();
	116
	117	/* Push out any further dirty data, and ensure cache is empty */
	118	flush_cache_all();
	119
	120	/* Switch to the identity mapping. */
	121	phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
	122	phys_reset((unsigned long)addr);
	123
	124	/* Should never get here. */
	125	BUG();
	126	}
	127
	128	void soft_restart(unsigned long addr)
	129	{
	130	u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
	131
	132	/* Disable interrupts first */
	133	local_irq_disable();
	134	local_fiq_disable();
	135
	136	/* Disable the L2 if we're the last man standing. */
	137	if (num_online_cpus() == 1)
	138	outer_disable();
	139
	140	/* Change to the new stack and continue with the reset. */
	141	call_with_stack(__soft_restart, (void )addr, (void )stack);
	142
	143	/* Should never get here. */
	144	BUG();
	145	}
	146
	147	static void null_restart(char mode, const char *cmd)
	148	{
	149	}
	150
	151	/*
	152	* Function pointers to optional machine specific functions
	153	*/
	154	void (*pm_power_off)(void);
	155	EXPORT_SYMBOL(pm_power_off);
	156
	157	void (arm_pm_restart)(char str, const char cmd) = null_restart;
	158	EXPORT_SYMBOL_GPL(arm_pm_restart);
	159
	160	/*
	161	* This is our default idle handler.
	162	*/
	163
	164	void (*arm_pm_idle)(void);
	165
	166	static void default_idle(void)
	167	{
	168	if (arm_pm_idle)
	169	arm_pm_idle();
	170	else
	171	cpu_do_idle();
	172	local_irq_enable();
	173	}
	174
	175	void (*pm_idle)(void) = default_idle;
	176	EXPORT_SYMBOL(pm_idle);
	177
	178	/*
	179	* The idle thread, has rather strange semantics for calling pm_idle,
	180	* but this is what x86 does and we need to do the same, so that
	181	* things like cpuidle get called in the same way. The only difference
	182	* is that we always respect 'hlt_counter' to prevent low power idle.
	183	*/
	184	void cpu_idle(void)
	185	{
	186	local_fiq_enable();
	187
	188	/* endless idle loop with no priority at all */
	189	while (1) {
	190	tick_nohz_idle_enter();
	191	rcu_idle_enter();
	192	leds_event(led_idle_start);
	193	while (!need_resched()) {
	194	#ifdef CONFIG_HOTPLUG_CPU
	195	if (cpu_is_offline(smp_processor_id()))
	196	cpu_die();
	197	#endif
	198
	199	/*
	200	* We need to disable interrupts here
	201	* to ensure we don't miss a wakeup call.
	202	*/
	203	local_irq_disable();
	204	#ifdef CONFIG_PL310_ERRATA_769419
	205	wmb();
	206	#endif
	207	if (hlt_counter) {
	208	local_irq_enable();
	209	cpu_relax();
	210	} else if (!need_resched()) {
	211	stop_critical_timings();
	212	if (cpuidle_idle_call())
	213	pm_idle();
	214	start_critical_timings();
	215	/*
	216	* pm_idle functions must always
	217	* return with IRQs enabled.
	218	*/
	219	WARN_ON(irqs_disabled());
	220	} else
	221	local_irq_enable();
	222	}
	223	leds_event(led_idle_end);
	224	rcu_idle_exit();
	225	tick_nohz_idle_exit();
	226	schedule_preempt_disabled();
	227	}
	228	}
	229
	230	static char reboot_mode = 'h';
	231
	232	int __init reboot_setup(char *str)
	233	{
	234	reboot_mode = str[0];
	235	return 1;
	236	}
	237
	238	__setup("reboot=", reboot_setup);
	239
	240	void machine_shutdown(void)
	241	{
	242	#ifdef CONFIG_SMP
	243	smp_send_stop();
	244	#endif
	245	}
	246
	247	void machine_halt(void)
	248	{
	249	machine_shutdown();
	250	while (1);
	251	}
	252
	253	void machine_power_off(void)
	254	{
	255	machine_shutdown();
	256	if (pm_power_off)
	257	pm_power_off();
	258	}
	259
	260	void machine_restart(char *cmd)
	261	{
	262	machine_shutdown();
	263
	264	arm_pm_restart(reboot_mode, cmd);
	265
	266	/* Give a grace period for failure to restart of 1s */
	267	mdelay(1000);
	268
	269	/* Whoops - the platform was unable to reboot. Tell the user! */
	270	printk("Reboot failed -- System halted\n");
	271	while (1);
	272	}
	273
	274	void __show_regs(struct pt_regs *regs)
	275	{
	276	unsigned long flags;
	277	char buf[64];
	278
	279	printk("CPU: %d %s (%s %.*s)\n",
	280	raw_smp_processor_id(), print_tainted(),
	281	init_utsname()->release,
	282	(int)strcspn(init_utsname()->version, " "),
	283	init_utsname()->version);
	284	print_symbol("PC is at %s\n", instruction_pointer(regs));
	285	print_symbol("LR is at %s\n", regs->ARM_lr);
	286	printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
	287	"sp : %08lx ip : %08lx fp : %08lx\n",
	288	regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
	289	regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
	290	printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
	291	regs->ARM_r10, regs->ARM_r9,
	292	regs->ARM_r8);
	293	printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
	294	regs->ARM_r7, regs->ARM_r6,
	295	regs->ARM_r5, regs->ARM_r4);
	296	printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
	297	regs->ARM_r3, regs->ARM_r2,
	298	regs->ARM_r1, regs->ARM_r0);
	299
	300	flags = regs->ARM_cpsr;
	301	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
	302	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
	303	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
	304	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
	305	buf[4] = '\0';
	306
	307	printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
	308	buf, interrupts_enabled(regs) ? "n" : "ff",
	309	fast_interrupts_enabled(regs) ? "n" : "ff",
	310	processor_modes[processor_mode(regs)],
	311	isa_modes[isa_mode(regs)],
	312	get_fs() == get_ds() ? "kernel" : "user");
	313	#ifdef CONFIG_CPU_CP15
	314	{
	315	unsigned int ctrl;
	316
	317	buf[0] = '\0';
	318	#ifdef CONFIG_CPU_CP15_MMU
	319	{
	320	unsigned int transbase, dac;
	321	asm("mrc p15, 0, %0, c2, c0\n\t"
	322	"mrc p15, 0, %1, c3, c0\n"
	323	: "=r" (transbase), "=r" (dac));
	324	snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
	325	transbase, dac);
	326	}
	327	#endif
	328	asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
	329
	330	printk("Control: %08x%s\n", ctrl, buf);
	331	}
	332	#endif
	333	}
	334
	335	void show_regs(struct pt_regs * regs)
	336	{
	337	printk("\n");
	338	printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
	339	__show_regs(regs);
	340	dump_stack();
	341	}
	342
	343	ATOMIC_NOTIFIER_HEAD(thread_notify_head);
	344
	345	EXPORT_SYMBOL_GPL(thread_notify_head);
	346
	347	/*
	348	* Free current thread data structures etc..
	349	*/
	350	void exit_thread(void)
	351	{
	352	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
	353	}
	354
	355	void flush_thread(void)
	356	{
	357	struct thread_info *thread = current_thread_info();
	358	struct task_struct *tsk = current;
	359
	360	flush_ptrace_hw_breakpoint(tsk);
	361
	362	memset(thread->used_cp, 0, sizeof(thread->used_cp));
	363	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
	364	memset(&thread->fpstate, 0, sizeof(union fp_state));
	365
	366	thread_notify(THREAD_NOTIFY_FLUSH, thread);
	367	}
	368
	369	void release_thread(struct task_struct *dead_task)
	370	{
	371	}
	372
	373	asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
	374
	375	int
	376	copy_thread(unsigned long clone_flags, unsigned long stack_start,
	377	unsigned long stk_sz, struct task_struct p, struct pt_regs regs)
	378	{
	379	struct thread_info *thread = task_thread_info(p);
	380	struct pt_regs *childregs = task_pt_regs(p);
	381
	382	childregs = regs;
	383	childregs->ARM_r0 = 0;
	384	childregs->ARM_sp = stack_start;
	385
	386	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
	387	thread->cpu_context.sp = (unsigned long)childregs;
	388	thread->cpu_context.pc = (unsigned long)ret_from_fork;
	389
	390	clear_ptrace_hw_breakpoint(p);
	391
	392	if (clone_flags & CLONE_SETTLS)
	393	thread->tp_value = regs->ARM_r3;
	394
	395	thread_notify(THREAD_NOTIFY_COPY, thread);
	396
	397	return 0;
	398	}
	399
	400	/*
	401	* Fill in the task's elfregs structure for a core dump.
	402	*/
	403	int dump_task_regs(struct task_struct t, elf_gregset_t elfregs)
	404	{
	405	elf_core_copy_regs(elfregs, task_pt_regs(t));
	406	return 1;
	407	}
	408
	409	/*
	410	* fill in the fpe structure for a core dump...
	411	*/
	412	int dump_fpu (struct pt_regs regs, struct user_fp fp)
	413	{
	414	struct thread_info *thread = current_thread_info();
	415	int used_math = thread->used_cp[1] \| thread->used_cp[2];
	416
	417	if (used_math)
	418	memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
	419
	420	return used_math != 0;
	421	}
	422	EXPORT_SYMBOL(dump_fpu);
	423
	424	/*
	425	* Shuffle the argument into the correct register before calling the
	426	* thread function. r4 is the thread argument, r5 is the pointer to
	427	* the thread function, and r6 points to the exit function.
	428	*/
	429	extern void kernel_thread_helper(void);
	430	asm( ".pushsection .text\n"
	431	" .align\n"
	432	" .type kernel_thread_helper, #function\n"
	433	"kernel_thread_helper:\n"
	434	#ifdef CONFIG_TRACE_IRQFLAGS
	435	" bl trace_hardirqs_on\n"
	436	#endif
	437	" msr cpsr_c, r7\n"
	438	" mov r0, r4\n"
	439	" mov lr, r6\n"
	440	" mov pc, r5\n"
	441	" .size kernel_thread_helper, . - kernel_thread_helper\n"
	442	" .popsection");
	443
	444	#ifdef CONFIG_ARM_UNWIND
	445	extern void kernel_thread_exit(long code);
	446	asm( ".pushsection .text\n"
	447	" .align\n"
	448	" .type kernel_thread_exit, #function\n"
	449	"kernel_thread_exit:\n"
	450	" .fnstart\n"
	451	" .cantunwind\n"
	452	" bl do_exit\n"
	453	" nop\n"
	454	" .fnend\n"
	455	" .size kernel_thread_exit, . - kernel_thread_exit\n"
	456	" .popsection");
	457	#else
	458	#define kernel_thread_exit do_exit
	459	#endif
	460
	461	/*
	462	* Create a kernel thread.
	463	*/
	464	pid_t kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
	465	{
	466	struct pt_regs regs;
	467
	468	memset(&regs, 0, sizeof(regs));
	469
	470	regs.ARM_r4 = (unsigned long)arg;
	471	regs.ARM_r5 = (unsigned long)fn;
	472	regs.ARM_r6 = (unsigned long)kernel_thread_exit;
	473	regs.ARM_r7 = SVC_MODE \| PSR_ENDSTATE \| PSR_ISETSTATE;
	474	regs.ARM_pc = (unsigned long)kernel_thread_helper;
	475	regs.ARM_cpsr = regs.ARM_r7 \| PSR_I_BIT;
	476
	477	return do_fork(flags\|CLONE_VM\|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
	478	}
	479	EXPORT_SYMBOL(kernel_thread);
	480
	481	unsigned long get_wchan(struct task_struct *p)
	482	{
	483	struct stackframe frame;
	484	int count = 0;
	485	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	486	return 0;
	487
	488	frame.fp = thread_saved_fp(p);
	489	frame.sp = thread_saved_sp(p);
	490	frame.lr = 0; /* recovered from the stack */
	491	frame.pc = thread_saved_pc(p);
	492	do {
	493	int ret = unwind_frame(&frame);
	494	if (ret < 0)
	495	return 0;
	496	if (!in_sched_functions(frame.pc))
	497	return frame.pc;
	498	} while (count ++ < 16);
	499	return 0;
	500	}
	501
	502	unsigned long arch_randomize_brk(struct mm_struct *mm)
	503	{
	504	unsigned long range_end = mm->brk + 0x02000000;
	505	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
	506	}
	507
	508	#ifdef CONFIG_MMU
	509	/*
	510	* The vectors page is always readable from user space for the
	511	* atomic helpers and the signal restart code. Insert it into the
	512	* gate_vma so that it is visible through ptrace and /proc/<pid>/mem.
	513	*/
	514	static struct vm_area_struct gate_vma;
	515
	516	static int __init gate_vma_init(void)
	517	{
	518	gate_vma.vm_start = 0xffff0000;
	519	gate_vma.vm_end = 0xffff0000 + PAGE_SIZE;
	520	gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
	521	gate_vma.vm_flags = VM_READ \| VM_EXEC \|
	522	VM_MAYREAD \| VM_MAYEXEC;
	523	return 0;
	524	}
	525	arch_initcall(gate_vma_init);
	526
	527	struct vm_area_struct get_gate_vma(struct mm_struct mm)
	528	{
	529	return &gate_vma;
	530	}
	531
	532	int in_gate_area(struct mm_struct *mm, unsigned long addr)
	533	{
	534	return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
	535	}
	536
	537	int in_gate_area_no_mm(unsigned long addr)
	538	{
	539	return in_gate_area(NULL, addr);
	540	}
	541
	542	const char arch_vma_name(struct vm_area_struct vma)
	543	{
	544	return (vma == &gate_vma) ? "[vectors]" : NULL;
	545	}
	546	#endif