[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/leds.h>
#include <linux/reboot.h>

#include <asm/cacheflush.h>
#include <asm/idmap.h>
#include <asm/processor.h>
#include <asm/thread_notify.h>
#include <asm/stacktrace.h>
#include <asm/system_misc.h>
#include <asm/mach/time.h>
#include <asm/tls.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[] __maybe_unused = {
  "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[] __maybe_unused = {
  "ARM" , "Thumb" , "Jazelle", "ThumbEE"
};

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 */
	raw_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(enum reboot_mode reboot_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)(enum reboot_mode reboot_mode, const char *cmd) = null_restart;
EXPORT_SYMBOL_GPL(arm_pm_restart);

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

void (*arm_pm_idle)(void);

/*
 * Called from the core idle loop.
 */

void arch_cpu_idle(void)
{
	if (arm_pm_idle)
		arm_pm_idle();
	else
		cpu_do_idle();
	local_irq_enable();
}

void arch_cpu_idle_prepare(void)
{
	local_fiq_enable();
}

void arch_cpu_idle_enter(void)
{
	ledtrig_cpu(CPU_LED_IDLE_START);
#ifdef CONFIG_PL310_ERRATA_769419
	wmb();
#endif
}

void arch_cpu_idle_exit(void)
{
	ledtrig_cpu(CPU_LED_IDLE_END);
}

#ifdef CONFIG_HOTPLUG_CPU
void arch_cpu_idle_dead(void)
{
	cpu_die();
}
#endif

/*
 * Called by kexec, immediately prior to machine_kexec().
 *
 * This must completely disable all secondary CPUs; simply causing those CPUs
 * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
 * kexec'd kernel to use any and all RAM as it sees fit, without having to
 * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
 * functionality embodied in disable_nonboot_cpus() to achieve this.
 */
void machine_shutdown(void)
{
	disable_nonboot_cpus();
}

/*
 * Halting simply requires that the secondary CPUs stop performing any
 * activity (executing tasks, handling interrupts). smp_send_stop()
 * achieves this.
 */
void machine_halt(void)
{
	local_irq_disable();
	smp_send_stop();

	local_irq_disable();
	while (1);
}

/*
 * Power-off simply requires that the secondary CPUs stop performing any
 * activity (executing tasks, handling interrupts). smp_send_stop()
 * achieves this. When the system power is turned off, it will take all CPUs
 * with it.
 */
void machine_power_off(void)
{
	local_irq_disable();
	smp_send_stop();

	if (pm_power_off)
		pm_power_off();
}

/*
 * Restart requires that the secondary CPUs stop performing any activity
 * while the primary CPU resets the system. Systems with a single CPU can
 * use soft_restart() as their machine descriptor's .restart hook, since that
 * will cause the only available CPU to reset. Systems with multiple CPUs must
 * provide a HW restart implementation, to ensure that all CPUs reset at once.
 * This is required so that any code running after reset on the primary CPU
 * doesn't have to co-ordinate with other CPUs to ensure they aren't still
 * executing pre-reset code, and using RAM that the primary CPU's code wishes
 * to use. Implementing such co-ordination would be essentially impossible.
 */
void machine_restart(char *cmd)
{
	local_irq_disable();
	smp_send_stop();

	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");
	local_irq_disable();
	while (1);
}

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

	show_regs_print_info(KERN_DEFAULT);

	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';

#ifndef CONFIG_CPU_V7M
	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");
#else
	printk("xPSR: %08lx\n", regs->ARM_cpsr);
#endif

#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");
	__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 thread_info *thread = task_thread_info(p);
	struct pt_regs *childregs = task_pt_regs(p);

	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));

	if (likely(!(p->flags & PF_KTHREAD))) {
		*childregs = *current_pt_regs();
		childregs->ARM_r0 = 0;
		if (stack_start)
			childregs->ARM_sp = stack_start;
	} else {
		memset(childregs, 0, sizeof(struct pt_regs));
		thread->cpu_context.r4 = stk_sz;
		thread->cpu_context.r5 = stack_start;
		childregs->ARM_cpsr = SVC_MODE;
	}
	thread->cpu_context.pc = (unsigned long)ret_from_fork;
	thread->cpu_context.sp = (unsigned long)childregs;

	clear_ptrace_hw_breakpoint(p);

	if (clone_flags & CLONE_SETTLS)
		thread->tp_value[0] = childregs->ARM_r3;
	thread->tp_value[1] = get_tpuser();

	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);

unsigned long get_wchan(struct task_struct *p)
{
	struct stackframe frame;
	unsigned long stack_page;
	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);
	stack_page = (unsigned long)task_stack_page(p);
	do {
		if (frame.sp < stack_page ||
		    frame.sp >= stack_page + THREAD_SIZE ||
		    unwind_frame(&frame) < 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
#ifdef CONFIG_KUSER_HELPERS
/*
 * The vectors page is always readable from user space for the
 * atomic helpers. Insert it into the gate_vma so that it is visible
 * through ptrace and /proc/<pid>/mem.
 */
static struct vm_area_struct gate_vma = {
	.vm_start	= 0xffff0000,
	.vm_end		= 0xffff0000 + PAGE_SIZE,
	.vm_flags	= VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
};

static int __init gate_vma_init(void)
{
	gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
	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);
}
#define is_gate_vma(vma)	((vma) == &gate_vma)
#else
#define is_gate_vma(vma)	0
#endif

const char *arch_vma_name(struct vm_area_struct *vma)
{
	return is_gate_vma(vma) ? "[vectors]" :
		(vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
		 "[sigpage]" : NULL;
}

static struct page *signal_page;
extern struct page *get_signal_page(void);

int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
	struct mm_struct *mm = current->mm;
	unsigned long addr;
	int ret;

	if (!signal_page)
		signal_page = get_signal_page();
	if (!signal_page)
		return -ENOMEM;

	down_write(&mm->mmap_sem);
	addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
	if (IS_ERR_VALUE(addr)) {
		ret = addr;
		goto up_fail;
	}

	ret = install_special_mapping(mm, addr, PAGE_SIZE,
		VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
		&signal_page);

	if (ret == 0)
		mm->context.sigpage = addr;

 up_fail:
	up_write(&mm->mmap_sem);
	return ret;
}
#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>
fa8bbb13	33	#include <linux/leds.h>
7b6d864b	34	#include <linux/reboot.h>
1da177e4	35
9ca03a21	36	#include <asm/cacheflush.h>
9ecb47de	37	#include <asm/idmap.h>
1da177e4	38	#include <asm/processor.h>
d6551e88	39	#include <asm/thread_notify.h>
2d7c11bf	40	#include <asm/stacktrace.h>
779dd959	41	#include <asm/system_misc.h>
2ea83398	42	#include <asm/mach/time.h>
a4780ade	43	#include <asm/tls.h>
1da177e4	44
c743f380 NP	45	#ifdef CONFIG_CC_STACKPROTECTOR
	46	#include <linux/stackprotector.h>
	47	unsigned long __stack_chk_guard __read_mostly;
	48	EXPORT_SYMBOL(__stack_chk_guard);
	49	#endif
	50
e2e55fde	51	static const char *processor_modes[] __maybe_unused = {
ae0a846e RK	52	"USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
	53	"UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
	54	"USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
	55	"UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
	56	};
	57
e2e55fde	58	static const char *isa_modes[] __maybe_unused = {
909d6c6c GD	59	"ARM" , "Thumb" , "Jazelle", "ThumbEE"
	60	};
	61
290130a1 WD	62	extern void call_with_stack(void (fn)(void ), void arg, void sp);
	63	typedef void (*phys_reset_t)(unsigned long);
	64
	65	/*
	66	* A temporary stack to use for CPU reset. This is static so that we
	67	* don't clobber it with the identity mapping. When running with this
	68	* stack, any references to the current task will not work so you
	69	* should really do as little as possible before jumping to your reset
	70	* code.
	71	*/
	72	static u64 soft_restart_stack[16];
	73
	74	static void __soft_restart(void *addr)
74617fb6	75	{
290130a1	76	phys_reset_t phys_reset;
74617fb6	77
290130a1	78	/* Take out a flat memory mapping. */
5aafec15	79	setup_mm_for_reboot();
74617fb6	80
9ca03a21 RK	81	/* Clean and invalidate caches */
	82	flush_cache_all();
	83
	84	/* Turn off caching */
	85	cpu_proc_fin();
	86
	87	/* Push out any further dirty data, and ensure cache is empty */
	88	flush_cache_all();
	89
290130a1 WD	90	/* Switch to the identity mapping. */
	91	phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
	92	phys_reset((unsigned long)addr);
74617fb6	93
290130a1 WD	94	/* Should never get here. */
	95	BUG();
	96	}
	97
	98	void soft_restart(unsigned long addr)
	99	{
	100	u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
	101
	102	/* Disable interrupts first */
c7d442f4	103	raw_local_irq_disable();
290130a1 WD	104	local_fiq_disable();
	105
	106	/* Disable the L2 if we're the last man standing. */
	107	if (num_online_cpus() == 1)
	108	outer_disable();
	109
	110	/* Change to the new stack and continue with the reset. */
	111	call_with_stack(__soft_restart, (void )addr, (void )stack);
	112
	113	/* Should never get here. */
	114	BUG();
e879c862 RK	115	}
e879c862 RK	116
7b6d864b	117	static void null_restart(enum reboot_mode reboot_mode, const char *cmd)
e879c862	118	{
74617fb6 RP	119	}
74617fb6 RP	120
1da177e4	121	/*
74617fb6	122	* Function pointers to optional machine specific functions
1da177e4	123	*/
1da177e4 LT	124	void (*pm_power_off)(void);
	125	EXPORT_SYMBOL(pm_power_off);
	126
7b6d864b	127	void (arm_pm_restart)(enum reboot_mode reboot_mode, const char cmd) = null_restart;
74617fb6 RP	128	EXPORT_SYMBOL_GPL(arm_pm_restart);
74617fb6 RP	129
1da177e4	130	/*
4fa20439	131	* This is our default idle handler.
1da177e4	132	*/
4fa20439 NP	133
	134	void (*arm_pm_idle)(void);
	135
ad68cc7a NP	136	/*
	137	* Called from the core idle loop.
	138	*/
	139
	140	void arch_cpu_idle(void)
1da177e4	141	{
4fa20439 NP	142	if (arm_pm_idle)
	143	arm_pm_idle();
	144	else
ae940913	145	cpu_do_idle();
9ccdac36	146	local_irq_enable();
1da177e4 LT	147	}
1da177e4 LT	148
f7b861b7	149	void arch_cpu_idle_prepare(void)
1da177e4 LT	150	{
1da177e4 LT	151	local_fiq_enable();
f7b861b7	152	}
1da177e4	153
f7b861b7 TG	154	void arch_cpu_idle_enter(void)
	155	{
	156	ledtrig_cpu(CPU_LED_IDLE_START);
	157	#ifdef CONFIG_PL310_ERRATA_769419
	158	wmb();
a054a811	159	#endif
f7b861b7	160	}
a054a811	161
f7b861b7 TG	162	void arch_cpu_idle_exit(void)
	163	{
	164	ledtrig_cpu(CPU_LED_IDLE_END);
	165	}
	166
	167	#ifdef CONFIG_HOTPLUG_CPU
	168	void arch_cpu_idle_dead(void)
	169	{
	170	cpu_die();
	171	}
11ed0ba1	172	#endif
f7b861b7	173
19ab428f SW	174	/*
	175	* Called by kexec, immediately prior to machine_kexec().
	176	*
	177	* This must completely disable all secondary CPUs; simply causing those CPUs
	178	* to execute e.g. a RAM-based pin loop is not sufficient. This allows the
	179	* kexec'd kernel to use any and all RAM as it sees fit, without having to
	180	* avoid any code or data used by any SW CPU pin loop. The CPU hotplug
	181	* functionality embodied in disable_nonboot_cpus() to achieve this.
	182	*/
3d3f78d7	183	void machine_shutdown(void)
1da177e4	184	{
19ab428f	185	disable_nonboot_cpus();
1da177e4 LT	186	}
1da177e4 LT	187
19ab428f SW	188	/*
	189	* Halting simply requires that the secondary CPUs stop performing any
	190	* activity (executing tasks, handling interrupts). smp_send_stop()
	191	* achieves this.
	192	*/
3d3f78d7 RK	193	void machine_halt(void)
3d3f78d7 RK	194	{
44424c34	195	local_irq_disable();
19ab428f SW	196	smp_send_stop();
19ab428f SW	197
98bd8b96	198	local_irq_disable();
3d3f78d7 RK	199	while (1);
3d3f78d7 RK	200	}
1da177e4	201
19ab428f SW	202	/*
	203	* Power-off simply requires that the secondary CPUs stop performing any
	204	* activity (executing tasks, handling interrupts). smp_send_stop()
	205	* achieves this. When the system power is turned off, it will take all CPUs
	206	* with it.
	207	*/
1da177e4 LT	208	void machine_power_off(void)
1da177e4 LT	209	{
44424c34	210	local_irq_disable();
19ab428f SW	211	smp_send_stop();
19ab428f SW	212
1da177e4 LT	213	if (pm_power_off)
	214	pm_power_off();
	215	}
	216
19ab428f SW	217	/*
	218	* Restart requires that the secondary CPUs stop performing any activity
	219	* while the primary CPU resets the system. Systems with a single CPU can
	220	* use soft_restart() as their machine descriptor's .restart hook, since that
	221	* will cause the only available CPU to reset. Systems with multiple CPUs must
	222	* provide a HW restart implementation, to ensure that all CPUs reset at once.
	223	* This is required so that any code running after reset on the primary CPU
	224	* doesn't have to co-ordinate with other CPUs to ensure they aren't still
	225	* executing pre-reset code, and using RAM that the primary CPU's code wishes
	226	* to use. Implementing such co-ordination would be essentially impossible.
	227	*/
be093beb	228	void machine_restart(char *cmd)
1da177e4	229	{
44424c34	230	local_irq_disable();
19ab428f	231	smp_send_stop();
ac15e00b	232
be093beb	233	arm_pm_restart(reboot_mode, cmd);
ac15e00b RK	234
	235	/* Give a grace period for failure to restart of 1s */
	236	mdelay(1000);
	237
	238	/* Whoops - the platform was unable to reboot. Tell the user! */
	239	printk("Reboot failed -- System halted\n");
98bd8b96	240	local_irq_disable();
ac15e00b	241	while (1);
1da177e4 LT	242	}
1da177e4 LT	243
652a12ef	244	void __show_regs(struct pt_regs *regs)
1da177e4	245	{
154c772e RK	246	unsigned long flags;
154c772e RK	247	char buf[64];
1da177e4	248
a43cb95d TH	249	show_regs_print_info(KERN_DEFAULT);
a43cb95d TH	250
1da177e4 LT	251	print_symbol("PC is at %s\n", instruction_pointer(regs));
1da177e4 LT	252	print_symbol("LR is at %s\n", regs->ARM_lr);
154c772e	253	printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
1da177e4	254	"sp : %08lx ip : %08lx fp : %08lx\n",
154c772e RK	255	regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
154c772e RK	256	regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
1da177e4 LT	257	printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
	258	regs->ARM_r10, regs->ARM_r9,
	259	regs->ARM_r8);
	260	printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
	261	regs->ARM_r7, regs->ARM_r6,
	262	regs->ARM_r5, regs->ARM_r4);
	263	printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
	264	regs->ARM_r3, regs->ARM_r2,
	265	regs->ARM_r1, regs->ARM_r0);
154c772e RK	266
	267	flags = regs->ARM_cpsr;
	268	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
	269	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
	270	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
	271	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
	272	buf[4] = '\0';
	273
e2e55fde	274	#ifndef CONFIG_CPU_V7M
909d6c6c	275	printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
154c772e	276	buf, interrupts_enabled(regs) ? "n" : "ff",
1da177e4 LT	277	fast_interrupts_enabled(regs) ? "n" : "ff",
1da177e4 LT	278	processor_modes[processor_mode(regs)],
909d6c6c	279	isa_modes[isa_mode(regs)],
1da177e4	280	get_fs() == get_ds() ? "kernel" : "user");
e2e55fde UKK	281	#else
	282	printk("xPSR: %08lx\n", regs->ARM_cpsr);
	283	#endif
	284
154c772e	285	#ifdef CONFIG_CPU_CP15
1da177e4	286	{
f12d0d7c	287	unsigned int ctrl;
154c772e RK	288
154c772e RK	289	buf[0] = '\0';
f12d0d7c	290	#ifdef CONFIG_CPU_CP15_MMU
154c772e RK	291	{
	292	unsigned int transbase, dac;
	293	asm("mrc p15, 0, %0, c2, c0\n\t"
	294	"mrc p15, 0, %1, c3, c0\n"
	295	: "=r" (transbase), "=r" (dac));
	296	snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
	297	transbase, dac);
	298	}
f12d0d7c	299	#endif
154c772e RK	300	asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
	301
	302	printk("Control: %08x%s\n", ctrl, buf);
	303	}
f12d0d7c	304	#endif
1da177e4 LT	305	}
1da177e4 LT	306
652a12ef RK	307	void show_regs(struct pt_regs * regs)
	308	{
	309	printk("\n");
652a12ef	310	__show_regs(regs);
b380ab4f	311	dump_stack();
652a12ef RK	312	}
652a12ef RK	313
797245f5 RK	314	ATOMIC_NOTIFIER_HEAD(thread_notify_head);
	315
	316	EXPORT_SYMBOL_GPL(thread_notify_head);
	317
1da177e4 LT	318	/*
	319	* Free current thread data structures etc..
	320	*/
	321	void exit_thread(void)
	322	{
797245f5	323	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
1da177e4 LT	324	}
1da177e4 LT	325
1da177e4 LT	326	void flush_thread(void)
	327	{
	328	struct thread_info *thread = current_thread_info();
	329	struct task_struct *tsk = current;
	330
864232fa WD	331	flush_ptrace_hw_breakpoint(tsk);
864232fa WD	332
1da177e4 LT	333	memset(thread->used_cp, 0, sizeof(thread->used_cp));
1da177e4 LT	334	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
d6551e88 RK	335	memset(&thread->fpstate, 0, sizeof(union fp_state));
	336
	337	thread_notify(THREAD_NOTIFY_FLUSH, thread);
1da177e4 LT	338	}
	339
	340	void release_thread(struct task_struct *dead_task)
	341	{
1da177e4 LT	342	}
	343
	344	asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
	345
	346	int
6f2c55b8	347	copy_thread(unsigned long clone_flags, unsigned long stack_start,
afa86fc4	348	unsigned long stk_sz, struct task_struct *p)
1da177e4	349	{
815d5ec8 AV	350	struct thread_info *thread = task_thread_info(p);
815d5ec8 AV	351	struct pt_regs *childregs = task_pt_regs(p);
1da177e4	352
1da177e4	353	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
9e14f828	354
38a61b6b AV	355	if (likely(!(p->flags & PF_KTHREAD))) {
38a61b6b AV	356	childregs = current_pt_regs();
9e14f828	357	childregs->ARM_r0 = 0;
38a61b6b AV	358	if (stack_start)
38a61b6b AV	359	childregs->ARM_sp = stack_start;
9e14f828	360	} else {
9fff2fa0	361	memset(childregs, 0, sizeof(struct pt_regs));
9e14f828 AV	362	thread->cpu_context.r4 = stk_sz;
9e14f828 AV	363	thread->cpu_context.r5 = stack_start;
9e14f828 AV	364	childregs->ARM_cpsr = SVC_MODE;
9e14f828 AV	365	}
9fff2fa0	366	thread->cpu_context.pc = (unsigned long)ret_from_fork;
1da177e4	367	thread->cpu_context.sp = (unsigned long)childregs;
1da177e4	368
864232fa WD	369	clear_ptrace_hw_breakpoint(p);
864232fa WD	370
1da177e4	371	if (clone_flags & CLONE_SETTLS)
a4780ade AH	372	thread->tp_value[0] = childregs->ARM_r3;
a4780ade AH	373	thread->tp_value[1] = get_tpuser();
1da177e4	374
2e82669a CM	375	thread_notify(THREAD_NOTIFY_COPY, thread);
2e82669a CM	376
1da177e4 LT	377	return 0;
	378	}
	379
cde3f860 AB	380	/*
	381	* Fill in the task's elfregs structure for a core dump.
	382	*/
	383	int dump_task_regs(struct task_struct t, elf_gregset_t elfregs)
	384	{
	385	elf_core_copy_regs(elfregs, task_pt_regs(t));
	386	return 1;
	387	}
	388
1da177e4 LT	389	/*
	390	* fill in the fpe structure for a core dump...
	391	*/
	392	int dump_fpu (struct pt_regs regs, struct user_fp fp)
	393	{
	394	struct thread_info *thread = current_thread_info();
	395	int used_math = thread->used_cp[1] \| thread->used_cp[2];
	396
	397	if (used_math)
	398	memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
	399
	400	return used_math != 0;
	401	}
	402	EXPORT_SYMBOL(dump_fpu);
	403
1da177e4 LT	404	unsigned long get_wchan(struct task_struct *p)
1da177e4 LT	405	{
2d7c11bf	406	struct stackframe frame;
1b15ec7a	407	unsigned long stack_page;
1da177e4 LT	408	int count = 0;
	409	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	410	return 0;
	411
2d7c11bf CM	412	frame.fp = thread_saved_fp(p);
	413	frame.sp = thread_saved_sp(p);
	414	frame.lr = 0; /* recovered from the stack */
	415	frame.pc = thread_saved_pc(p);
1b15ec7a	416	stack_page = (unsigned long)task_stack_page(p);
1da177e4	417	do {
1b15ec7a KK	418	if (frame.sp < stack_page \|\|
	419	frame.sp >= stack_page + THREAD_SIZE \|\|
	420	unwind_frame(&frame) < 0)
1da177e4	421	return 0;
2d7c11bf CM	422	if (!in_sched_functions(frame.pc))
2d7c11bf CM	423	return frame.pc;
1da177e4 LT	424	} while (count ++ < 16);
	425	return 0;
	426	}
990cb8ac NP	427
	428	unsigned long arch_randomize_brk(struct mm_struct *mm)
	429	{
	430	unsigned long range_end = mm->brk + 0x02000000;
	431	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
	432	}
ec706dab	433
6cde6d42	434	#ifdef CONFIG_MMU
a5463cd3	435	#ifdef CONFIG_KUSER_HELPERS
ec706dab NP	436	/*
ec706dab NP	437	* The vectors page is always readable from user space for the
48be69a0 RK	438	* atomic helpers. Insert it into the gate_vma so that it is visible
48be69a0 RK	439	* through ptrace and /proc/<pid>/mem.
ec706dab	440	*/
f6604efe RK	441	static struct vm_area_struct gate_vma = {
	442	.vm_start = 0xffff0000,
	443	.vm_end = 0xffff0000 + PAGE_SIZE,
	444	.vm_flags = VM_READ \| VM_EXEC \| VM_MAYREAD \| VM_MAYEXEC,
f6604efe	445	};
ec706dab	446
f9d4861f	447	static int __init gate_vma_init(void)
ec706dab	448	{
f6604efe	449	gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
f9d4861f WD	450	return 0;
	451	}
	452	arch_initcall(gate_vma_init);
	453
	454	struct vm_area_struct get_gate_vma(struct mm_struct mm)
	455	{
	456	return &gate_vma;
	457	}
	458
	459	int in_gate_area(struct mm_struct *mm, unsigned long addr)
	460	{
	461	return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
	462	}
	463
	464	int in_gate_area_no_mm(unsigned long addr)
	465	{
	466	return in_gate_area(NULL, addr);
ec706dab	467	}
1d0bbf42	468	#define is_gate_vma(vma) ((vma) == &gate_vma)
a5463cd3 RK	469	#else
	470	#define is_gate_vma(vma) 0
	471	#endif
ec706dab NP	472
	473	const char arch_vma_name(struct vm_area_struct vma)
	474	{
a5463cd3	475	return is_gate_vma(vma) ? "[vectors]" :
48be69a0 RK	476	(vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
	477	"[sigpage]" : NULL;
	478	}
	479
e0d40756	480	static struct page *signal_page;
48be69a0 RK	481	extern struct page *get_signal_page(void);
	482
	483	int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
	484	{
	485	struct mm_struct *mm = current->mm;
48be69a0 RK	486	unsigned long addr;
	487	int ret;
	488
e0d40756 RK	489	if (!signal_page)
	490	signal_page = get_signal_page();
	491	if (!signal_page)
48be69a0 RK	492	return -ENOMEM;
	493
	494	down_write(&mm->mmap_sem);
	495	addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
	496	if (IS_ERR_VALUE(addr)) {
	497	ret = addr;
	498	goto up_fail;
	499	}
	500
	501	ret = install_special_mapping(mm, addr, PAGE_SIZE,
	502	VM_READ \| VM_EXEC \| VM_MAYREAD \| VM_MAYWRITE \| VM_MAYEXEC,
e0d40756	503	&signal_page);
48be69a0 RK	504
	505	if (ret == 0)
	506	mm->context.sigpage = addr;
	507
	508	up_fail:
	509	up_write(&mm->mmap_sem);
	510	return ret;
ec706dab	511	}
6cde6d42	512	#endif