/* *  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 <linux/leds.h> #include <asm/cacheflush.h>#include <asm/idmap.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"}; static volatile int hlt_counter; void disable_hlt(void){	hlt_counter++;} EXPORT_SYMBOL(disable_hlt); void enable_hlt(void){	hlt_counter--;	BUG_ON(hlt_counter < 0);} 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();} /* * The idle thread. * 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();		ledtrig_cpu(CPU_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())					default_idle();				start_critical_timings();				/*				 * default_idle functions must always				 * return with IRQs enabled.				 */				WARN_ON(irqs_disabled());			} else				local_irq_enable();		}		ledtrig_cpu(CPU_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();	local_irq_disable();	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");	local_irq_disable();	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"); intcopy_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 = childregs->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); 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