[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);

static void do_nothing(void *unused)
{
}

/*
 * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
 * pm_idle and update to new pm_idle value. Required while changing pm_idle
 * handler on SMP systems.
 *
 * Caller must have changed pm_idle to the new value before the call. Old
 * pm_idle value will not be used by any CPU after the return of this function.
 */
void cpu_idle_wait(void)
{
	smp_mb();
	/* kick all the CPUs so that they exit out of pm_idle */
	smp_call_function(do_nothing, NULL, 1);
}
EXPORT_SYMBOL_GPL(cpu_idle_wait);

/*
 * 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.  Let's declare a mapping
 * for it so it is visible through ptrace and /proc/<pid>/mem.
 */

int vectors_user_mapping(void)
{
	struct mm_struct *mm = current->mm;
	return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
				       VM_READ | VM_EXEC |
				       VM_MAYREAD | VM_MAYEXEC | VM_RESERVED,
				       NULL);
}

const char *arch_vma_name(struct vm_area_struct *vma)
{
	return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
}
#endif
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
ecea4ab6	13	#include <linux/export.h>
1da177e4 LT	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>
990cb8ac	31	#include <linux/random.h>
864232fa	32	#include <linux/hw_breakpoint.h>
a0bfa137	33	#include <linux/cpuidle.h>
1da177e4	34
9ca03a21	35	#include <asm/cacheflush.h>
1da177e4 LT	36	#include <asm/leds.h>
1da177e4 LT	37	#include <asm/processor.h>
d6551e88	38	#include <asm/thread_notify.h>
2d7c11bf	39	#include <asm/stacktrace.h>
2ea83398	40	#include <asm/mach/time.h>
1da177e4	41
c743f380 NP	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
ae0a846e RK	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
909d6c6c GD	55	static const char *isa_modes[] = {
	56	"ARM" , "Thumb" , "Jazelle", "ThumbEE"
	57	};
	58
5aafec15	59	extern void setup_mm_for_reboot(void);
1da177e4 LT	60
	61	static volatile int hlt_counter;
	62
1da177e4 LT	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
290130a1 WD	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)
74617fb6	105	{
290130a1	106	phys_reset_t phys_reset;
74617fb6	107
290130a1	108	/* Take out a flat memory mapping. */
5aafec15	109	setup_mm_for_reboot();
74617fb6	110
9ca03a21 RK	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
290130a1 WD	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);
74617fb6	123
290130a1 WD	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();
e879c862 RK	145	}
e879c862 RK	146
f88b8979	147	static void null_restart(char mode, const char *cmd)
e879c862	148	{
74617fb6 RP	149	}
74617fb6 RP	150
1da177e4	151	/*
74617fb6	152	* Function pointers to optional machine specific functions
1da177e4	153	*/
1da177e4 LT	154	void (*pm_power_off)(void);
	155	EXPORT_SYMBOL(pm_power_off);
	156
f88b8979	157	void (arm_pm_restart)(char str, const char cmd) = null_restart;
74617fb6 RP	158	EXPORT_SYMBOL_GPL(arm_pm_restart);
74617fb6 RP	159
c7b0aff4 KH	160	static void do_nothing(void *unused)
	161	{
	162	}
	163
	164	/*
	165	* cpu_idle_wait - Used to ensure that all the CPUs discard old value of
	166	* pm_idle and update to new pm_idle value. Required while changing pm_idle
	167	* handler on SMP systems.
	168	*
	169	* Caller must have changed pm_idle to the new value before the call. Old
	170	* pm_idle value will not be used by any CPU after the return of this function.
	171	*/
	172	void cpu_idle_wait(void)
	173	{
	174	smp_mb();
	175	/* kick all the CPUs so that they exit out of pm_idle */
	176	smp_call_function(do_nothing, NULL, 1);
	177	}
	178	EXPORT_SYMBOL_GPL(cpu_idle_wait);
74617fb6	179
1da177e4	180	/*
4fa20439	181	* This is our default idle handler.
1da177e4	182	*/
4fa20439 NP	183
	184	void (*arm_pm_idle)(void);
	185
84dff1a7	186	static void default_idle(void)
1da177e4	187	{
4fa20439 NP	188	if (arm_pm_idle)
	189	arm_pm_idle();
	190	else
ae940913	191	cpu_do_idle();
9ccdac36	192	local_irq_enable();
1da177e4 LT	193	}
1da177e4 LT	194
9ccdac36 RK	195	void (*pm_idle)(void) = default_idle;
	196	EXPORT_SYMBOL(pm_idle);
	197
1da177e4	198	/*
9ccdac36 RK	199	* The idle thread, has rather strange semantics for calling pm_idle,
	200	* but this is what x86 does and we need to do the same, so that
	201	* things like cpuidle get called in the same way. The only difference
	202	* is that we always respect 'hlt_counter' to prevent low power idle.
1da177e4 LT	203	*/
	204	void cpu_idle(void)
	205	{
	206	local_fiq_enable();
	207
	208	/* endless idle loop with no priority at all */
	209	while (1) {
1268fbc7 FW	210	tick_nohz_idle_enter();
1268fbc7 FW	211	rcu_idle_enter();
9ccdac36 RK	212	leds_event(led_idle_start);
9ccdac36 RK	213	while (!need_resched()) {
a054a811	214	#ifdef CONFIG_HOTPLUG_CPU
9ccdac36 RK	215	if (cpu_is_offline(smp_processor_id()))
9ccdac36 RK	216	cpu_die();
a054a811 RK	217	#endif
a054a811 RK	218
4fa20439 NP	219	/*
	220	* We need to disable interrupts here
	221	* to ensure we don't miss a wakeup call.
	222	*/
9ccdac36	223	local_irq_disable();
11ed0ba1 WD	224	#ifdef CONFIG_PL310_ERRATA_769419
	225	wmb();
	226	#endif
9ccdac36 RK	227	if (hlt_counter) {
	228	local_irq_enable();
	229	cpu_relax();
4fa20439	230	} else if (!need_resched()) {
9ccdac36	231	stop_critical_timings();
cbc158d6	232	if (cpuidle_idle_call())
a0bfa137	233	pm_idle();
9ccdac36 RK	234	start_critical_timings();
9ccdac36 RK	235	/*
4fa20439 NP	236	* pm_idle functions must always
4fa20439 NP	237	* return with IRQs enabled.
9ccdac36 RK	238	*/
9ccdac36 RK	239	WARN_ON(irqs_disabled());
4fa20439	240	} else
9ccdac36	241	local_irq_enable();
9ccdac36	242	}
1da177e4	243	leds_event(led_idle_end);
1268fbc7 FW	244	rcu_idle_exit();
1268fbc7 FW	245	tick_nohz_idle_exit();
bd2f5536	246	schedule_preempt_disabled();
1da177e4 LT	247	}
	248	}
	249
	250	static char reboot_mode = 'h';
	251
	252	int __init reboot_setup(char *str)
	253	{
	254	reboot_mode = str[0];
	255	return 1;
	256	}
	257
	258	__setup("reboot=", reboot_setup);
	259
3d3f78d7	260	void machine_shutdown(void)
1da177e4	261	{
3d3f78d7 RK	262	#ifdef CONFIG_SMP
	263	smp_send_stop();
	264	#endif
1da177e4 LT	265	}
1da177e4 LT	266
3d3f78d7 RK	267	void machine_halt(void)
	268	{
	269	machine_shutdown();
	270	while (1);
	271	}
1da177e4 LT	272
	273	void machine_power_off(void)
	274	{
3d3f78d7	275	machine_shutdown();
1da177e4 LT	276	if (pm_power_off)
	277	pm_power_off();
	278	}
	279
be093beb	280	void machine_restart(char *cmd)
1da177e4	281	{
3d3f78d7	282	machine_shutdown();
ac15e00b	283
be093beb	284	arm_pm_restart(reboot_mode, cmd);
ac15e00b RK	285
	286	/* Give a grace period for failure to restart of 1s */
	287	mdelay(1000);
	288
	289	/* Whoops - the platform was unable to reboot. Tell the user! */
	290	printk("Reboot failed -- System halted\n");
	291	while (1);
1da177e4 LT	292	}
1da177e4 LT	293
652a12ef	294	void __show_regs(struct pt_regs *regs)
1da177e4	295	{
154c772e RK	296	unsigned long flags;
154c772e RK	297	char buf[64];
1da177e4	298
154c772e	299	printk("CPU: %d %s (%s %.*s)\n",
22325525 RV	300	raw_smp_processor_id(), print_tainted(),
22325525 RV	301	init_utsname()->release,
154c772e RK	302	(int)strcspn(init_utsname()->version, " "),
154c772e RK	303	init_utsname()->version);
1da177e4 LT	304	print_symbol("PC is at %s\n", instruction_pointer(regs));
1da177e4 LT	305	print_symbol("LR is at %s\n", regs->ARM_lr);
154c772e	306	printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
1da177e4	307	"sp : %08lx ip : %08lx fp : %08lx\n",
154c772e RK	308	regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
154c772e RK	309	regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
1da177e4 LT	310	printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
	311	regs->ARM_r10, regs->ARM_r9,
	312	regs->ARM_r8);
	313	printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
	314	regs->ARM_r7, regs->ARM_r6,
	315	regs->ARM_r5, regs->ARM_r4);
	316	printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
	317	regs->ARM_r3, regs->ARM_r2,
	318	regs->ARM_r1, regs->ARM_r0);
154c772e RK	319
	320	flags = regs->ARM_cpsr;
	321	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
	322	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
	323	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
	324	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
	325	buf[4] = '\0';
	326
909d6c6c	327	printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
154c772e	328	buf, interrupts_enabled(regs) ? "n" : "ff",
1da177e4 LT	329	fast_interrupts_enabled(regs) ? "n" : "ff",
1da177e4 LT	330	processor_modes[processor_mode(regs)],
909d6c6c	331	isa_modes[isa_mode(regs)],
1da177e4	332	get_fs() == get_ds() ? "kernel" : "user");
154c772e	333	#ifdef CONFIG_CPU_CP15
1da177e4	334	{
f12d0d7c	335	unsigned int ctrl;
154c772e RK	336
154c772e RK	337	buf[0] = '\0';
f12d0d7c	338	#ifdef CONFIG_CPU_CP15_MMU
154c772e RK	339	{
	340	unsigned int transbase, dac;
	341	asm("mrc p15, 0, %0, c2, c0\n\t"
	342	"mrc p15, 0, %1, c3, c0\n"
	343	: "=r" (transbase), "=r" (dac));
	344	snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
	345	transbase, dac);
	346	}
f12d0d7c	347	#endif
154c772e RK	348	asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
	349
	350	printk("Control: %08x%s\n", ctrl, buf);
	351	}
f12d0d7c	352	#endif
1da177e4 LT	353	}
1da177e4 LT	354
652a12ef RK	355	void show_regs(struct pt_regs * regs)
	356	{
	357	printk("\n");
19c5870c	358	printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
652a12ef	359	__show_regs(regs);
b380ab4f	360	dump_stack();
652a12ef RK	361	}
652a12ef RK	362
797245f5 RK	363	ATOMIC_NOTIFIER_HEAD(thread_notify_head);
	364
	365	EXPORT_SYMBOL_GPL(thread_notify_head);
	366
1da177e4 LT	367	/*
	368	* Free current thread data structures etc..
	369	*/
	370	void exit_thread(void)
	371	{
797245f5	372	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
1da177e4 LT	373	}
1da177e4 LT	374
1da177e4 LT	375	void flush_thread(void)
	376	{
	377	struct thread_info *thread = current_thread_info();
	378	struct task_struct *tsk = current;
	379
864232fa WD	380	flush_ptrace_hw_breakpoint(tsk);
864232fa WD	381
1da177e4 LT	382	memset(thread->used_cp, 0, sizeof(thread->used_cp));
1da177e4 LT	383	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
d6551e88 RK	384	memset(&thread->fpstate, 0, sizeof(union fp_state));
	385
	386	thread_notify(THREAD_NOTIFY_FLUSH, thread);
1da177e4 LT	387	}
	388
	389	void release_thread(struct task_struct *dead_task)
	390	{
1da177e4 LT	391	}
	392
	393	asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
	394
	395	int
6f2c55b8	396	copy_thread(unsigned long clone_flags, unsigned long stack_start,
1da177e4 LT	397	unsigned long stk_sz, struct task_struct p, struct pt_regs regs)
1da177e4 LT	398	{
815d5ec8 AV	399	struct thread_info *thread = task_thread_info(p);
815d5ec8 AV	400	struct pt_regs *childregs = task_pt_regs(p);
1da177e4	401
1da177e4 LT	402	childregs = regs;
	403	childregs->ARM_r0 = 0;
	404	childregs->ARM_sp = stack_start;
	405
	406	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
	407	thread->cpu_context.sp = (unsigned long)childregs;
	408	thread->cpu_context.pc = (unsigned long)ret_from_fork;
	409
864232fa WD	410	clear_ptrace_hw_breakpoint(p);
864232fa WD	411
1da177e4 LT	412	if (clone_flags & CLONE_SETTLS)
	413	thread->tp_value = regs->ARM_r3;
	414
2e82669a CM	415	thread_notify(THREAD_NOTIFY_COPY, thread);
2e82669a CM	416
1da177e4 LT	417	return 0;
	418	}
	419
cde3f860 AB	420	/*
	421	* Fill in the task's elfregs structure for a core dump.
	422	*/
	423	int dump_task_regs(struct task_struct t, elf_gregset_t elfregs)
	424	{
	425	elf_core_copy_regs(elfregs, task_pt_regs(t));
	426	return 1;
	427	}
	428
1da177e4 LT	429	/*
	430	* fill in the fpe structure for a core dump...
	431	*/
	432	int dump_fpu (struct pt_regs regs, struct user_fp fp)
	433	{
	434	struct thread_info *thread = current_thread_info();
	435	int used_math = thread->used_cp[1] \| thread->used_cp[2];
	436
	437	if (used_math)
	438	memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
	439
	440	return used_math != 0;
	441	}
	442	EXPORT_SYMBOL(dump_fpu);
	443
1da177e4 LT	444	/*
1da177e4 LT	445	* Shuffle the argument into the correct register before calling the
ac78884e RK	446	* thread function. r4 is the thread argument, r5 is the pointer to
ac78884e RK	447	* the thread function, and r6 points to the exit function.
1da177e4 LT	448	*/
1da177e4 LT	449	extern void kernel_thread_helper(void);
4260415f	450	asm( ".pushsection .text\n"
1da177e4 LT	451	" .align\n"
	452	" .type kernel_thread_helper, #function\n"
	453	"kernel_thread_helper:\n"
ac78884e RK	454	#ifdef CONFIG_TRACE_IRQFLAGS
	455	" bl trace_hardirqs_on\n"
	456	#endif
	457	" msr cpsr_c, r7\n"
	458	" mov r0, r4\n"
	459	" mov lr, r6\n"
	460	" mov pc, r5\n"
1da177e4	461	" .size kernel_thread_helper, . - kernel_thread_helper\n"
4260415f	462	" .popsection");
1da177e4	463
feb97c36 CM	464	#ifdef CONFIG_ARM_UNWIND
feb97c36 CM	465	extern void kernel_thread_exit(long code);
4260415f	466	asm( ".pushsection .text\n"
feb97c36 CM	467	" .align\n"
	468	" .type kernel_thread_exit, #function\n"
	469	"kernel_thread_exit:\n"
	470	" .fnstart\n"
	471	" .cantunwind\n"
	472	" bl do_exit\n"
	473	" nop\n"
	474	" .fnend\n"
	475	" .size kernel_thread_exit, . - kernel_thread_exit\n"
4260415f	476	" .popsection");
feb97c36 CM	477	#else
	478	#define kernel_thread_exit do_exit
	479	#endif
	480
1da177e4 LT	481	/*
	482	* Create a kernel thread.
	483	*/
	484	pid_t kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
	485	{
	486	struct pt_regs regs;
	487
	488	memset(&regs, 0, sizeof(regs));
	489
ac78884e RK	490	regs.ARM_r4 = (unsigned long)arg;
	491	regs.ARM_r5 = (unsigned long)fn;
	492	regs.ARM_r6 = (unsigned long)kernel_thread_exit;
	493	regs.ARM_r7 = SVC_MODE \| PSR_ENDSTATE \| PSR_ISETSTATE;
1da177e4	494	regs.ARM_pc = (unsigned long)kernel_thread_helper;
ac78884e	495	regs.ARM_cpsr = regs.ARM_r7 \| PSR_I_BIT;
1da177e4 LT	496
	497	return do_fork(flags\|CLONE_VM\|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
	498	}
	499	EXPORT_SYMBOL(kernel_thread);
	500
	501	unsigned long get_wchan(struct task_struct *p)
	502	{
2d7c11bf	503	struct stackframe frame;
1da177e4 LT	504	int count = 0;
	505	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	506	return 0;
	507
2d7c11bf CM	508	frame.fp = thread_saved_fp(p);
	509	frame.sp = thread_saved_sp(p);
	510	frame.lr = 0; /* recovered from the stack */
	511	frame.pc = thread_saved_pc(p);
1da177e4	512	do {
2d7c11bf CM	513	int ret = unwind_frame(&frame);
2d7c11bf CM	514	if (ret < 0)
1da177e4	515	return 0;
2d7c11bf CM	516	if (!in_sched_functions(frame.pc))
2d7c11bf CM	517	return frame.pc;
1da177e4 LT	518	} while (count ++ < 16);
	519	return 0;
	520	}
990cb8ac NP	521
	522	unsigned long arch_randomize_brk(struct mm_struct *mm)
	523	{
	524	unsigned long range_end = mm->brk + 0x02000000;
	525	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
	526	}
ec706dab	527
6cde6d42	528	#ifdef CONFIG_MMU
ec706dab NP	529	/*
	530	* The vectors page is always readable from user space for the
	531	* atomic helpers and the signal restart code. Let's declare a mapping
	532	* for it so it is visible through ptrace and /proc/<pid>/mem.
	533	*/
	534
	535	int vectors_user_mapping(void)
	536	{
	537	struct mm_struct *mm = current->mm;
	538	return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
	539	VM_READ \| VM_EXEC \|
909af768	540	VM_MAYREAD \| VM_MAYEXEC \| VM_RESERVED,
ec706dab NP	541	NULL);
	542	}
	543
	544	const char arch_vma_name(struct vm_area_struct vma)
	545	{
	546	return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
	547	}
6cde6d42	548	#endif