/* *  linux/arch/arm/kernel/process.c * *  Copyright (C) 1996-2000 Russell King - Converted to ARM. *  Original Copyright (C) 1995  Linus Torvalds * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */#include <stdarg.h> #include <linux/module.h>#include <linux/sched.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/stddef.h>#include <linux/unistd.h>#include <linux/user.h>#include <linux/delay.h>#include <linux/reboot.h>#include <linux/interrupt.h>#include <linux/kallsyms.h>#include <linux/init.h>#include <linux/cpu.h>#include <linux/elfcore.h>#include <linux/pm.h>#include <linux/tick.h>#include <linux/utsname.h>#include <linux/uaccess.h> #include <asm/leds.h>#include <asm/processor.h>#include <asm/system.h>#include <asm/thread_notify.h>#include <asm/stacktrace.h>#include <asm/mach/time.h> static const char *processor_modes[] = {  "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,  "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",  "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,  "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"}; static const char *isa_modes[] = {  "ARM" , "Thumb" , "Jazelle", "ThumbEE"}; extern void setup_mm_for_reboot(char mode); static volatile int hlt_counter; #include <mach/system.h> void disable_hlt(void){	hlt_counter++;} EXPORT_SYMBOL(disable_hlt); void enable_hlt(void){	hlt_counter--;} EXPORT_SYMBOL(enable_hlt); static int __init nohlt_setup(char *__unused){	hlt_counter = 1;	return 1;} static int __init hlt_setup(char *__unused){	hlt_counter = 0;	return 1;} __setup("nohlt", nohlt_setup);__setup("hlt", hlt_setup); void arm_machine_restart(char mode, const char *cmd){	/*	 * Clean and disable cache, and turn off interrupts	 */	cpu_proc_fin(); 	/*	 * Tell the mm system that we are going to reboot -	 * we may need it to insert some 1:1 mappings so that	 * soft boot works.	 */	setup_mm_for_reboot(mode); 	/*	 * Now call the architecture specific reboot code.	 */	arch_reset(mode, cmd); 	/*	 * Whoops - the architecture was unable to reboot.	 * Tell the user!	 */	mdelay(1000);	printk("Reboot failed -- System halted\n");	while (1);} /* * Function pointers to optional machine specific functions */void (*pm_power_off)(void);EXPORT_SYMBOL(pm_power_off); void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;EXPORT_SYMBOL_GPL(arm_pm_restart);  /* * This is our default idle handler.  We need to disable * interrupts here to ensure we don't miss a wakeup call. */static void default_idle(void){	if (!need_resched())		arch_idle();	local_irq_enable();} void (*pm_idle)(void) = default_idle;EXPORT_SYMBOL(pm_idle); /* * The idle thread, has rather strange semantics for calling pm_idle, * but this is what x86 does and we need to do the same, so that * things like cpuidle get called in the same way.  The only difference * is that we always respect 'hlt_counter' to prevent low power idle. */void cpu_idle(void){	local_fiq_enable(); 	/* endless idle loop with no priority at all */	while (1) {		tick_nohz_stop_sched_tick(1);		leds_event(led_idle_start);		while (!need_resched()) {#ifdef CONFIG_HOTPLUG_CPU			if (cpu_is_offline(smp_processor_id()))				cpu_die();#endif 			local_irq_disable();			if (hlt_counter) {				local_irq_enable();				cpu_relax();			} else {				stop_critical_timings();				pm_idle();				start_critical_timings();				/*				 * This will eventually be removed - pm_idle				 * functions should always return with IRQs				 * enabled.				 */				WARN_ON(irqs_disabled());				local_irq_enable();			}		}		leds_event(led_idle_end);		tick_nohz_restart_sched_tick();		preempt_enable_no_resched();		schedule();		preempt_disable();	}} static char reboot_mode = 'h'; int __init reboot_setup(char *str){	reboot_mode = str[0];	return 1;} __setup("reboot=", reboot_setup); void machine_halt(void){}  void machine_power_off(void){	if (pm_power_off)		pm_power_off();} void machine_restart(char *cmd){	arm_pm_restart(reboot_mode, cmd);} void __show_regs(struct pt_regs *regs){	unsigned long flags;	char buf[64]; 	printk("CPU: %d    %s  (%s %.*s)\n",		raw_smp_processor_id(), print_tainted(),		init_utsname()->release,		(int)strcspn(init_utsname()->version, " "),		init_utsname()->version);	print_symbol("PC is at %s\n", instruction_pointer(regs));	print_symbol("LR is at %s\n", regs->ARM_lr);	printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"	       "sp : %08lx  ip : %08lx  fp : %08lx\n",		regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,		regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);	printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",		regs->ARM_r10, regs->ARM_r9,		regs->ARM_r8);	printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",		regs->ARM_r7, regs->ARM_r6,		regs->ARM_r5, regs->ARM_r4);	printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",		regs->ARM_r3, regs->ARM_r2,		regs->ARM_r1, regs->ARM_r0); 	flags = regs->ARM_cpsr;	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';	buf[4] = '\0'; 	printk("Flags: %s  IRQs o%s  FIQs o%s  Mode %s  ISA %s  Segment %s\n",		buf, interrupts_enabled(regs) ? "n" : "ff",		fast_interrupts_enabled(regs) ? "n" : "ff",		processor_modes[processor_mode(regs)],		isa_modes[isa_mode(regs)],		get_fs() == get_ds() ? "kernel" : "user");#ifdef CONFIG_CPU_CP15	{		unsigned int ctrl; 		buf[0] = '\0';#ifdef CONFIG_CPU_CP15_MMU		{			unsigned int transbase, dac;			asm("mrc p15, 0, %0, c2, c0\n\t"			    "mrc p15, 0, %1, c3, c0\n"			    : "=r" (transbase), "=r" (dac));			snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",			  	transbase, dac);		}#endif		asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); 		printk("Control: %08x%s\n", ctrl, buf);	}#endif} void show_regs(struct pt_regs * regs){	printk("\n");	printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);	__show_regs(regs);	__backtrace();} ATOMIC_NOTIFIER_HEAD(thread_notify_head); EXPORT_SYMBOL_GPL(thread_notify_head); /* * Free current thread data structures etc.. */void exit_thread(void){	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());} void flush_thread(void){	struct thread_info *thread = current_thread_info();	struct task_struct *tsk = current; 	memset(thread->used_cp, 0, sizeof(thread->used_cp));	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));	memset(&thread->fpstate, 0, sizeof(union fp_state)); 	thread_notify(THREAD_NOTIFY_FLUSH, thread);} void release_thread(struct task_struct *dead_task){} asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); intcopy_thread(unsigned long clone_flags, unsigned long stack_start,	    unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs){	struct thread_info *thread = task_thread_info(p);	struct pt_regs *childregs = task_pt_regs(p); 	*childregs = *regs;	childregs->ARM_r0 = 0;	childregs->ARM_sp = stack_start; 	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));	thread->cpu_context.sp = (unsigned long)childregs;	thread->cpu_context.pc = (unsigned long)ret_from_fork; 	if (clone_flags & CLONE_SETTLS)		thread->tp_value = regs->ARM_r3; 	return 0;} /* * Fill in the task's elfregs structure for a core dump. */int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs){	elf_core_copy_regs(elfregs, task_pt_regs(t));	return 1;} /* * fill in the fpe structure for a core dump... */int dump_fpu (struct pt_regs *regs, struct user_fp *fp){	struct thread_info *thread = current_thread_info();	int used_math = thread->used_cp[1] | thread->used_cp[2]; 	if (used_math)		memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 	return used_math != 0;}EXPORT_SYMBOL(dump_fpu); /* * Shuffle the argument into the correct register before calling the * thread function.  r4 is the thread argument, r5 is the pointer to * the thread function, and r6 points to the exit function. */extern void kernel_thread_helper(void);asm(	".pushsection .text\n""	.align\n""	.type	kernel_thread_helper, #function\n""kernel_thread_helper:\n"#ifdef CONFIG_TRACE_IRQFLAGS"	bl	trace_hardirqs_on\n"#endif"	msr	cpsr_c, r7\n""	mov	r0, r4\n""	mov	lr, r6\n""	mov	pc, r5\n""	.size	kernel_thread_helper, . - kernel_thread_helper\n""	.popsection"); #ifdef CONFIG_ARM_UNWINDextern 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;}