/* * linux/arch/unicore32/kernel/process.c * * Code specific to PKUnity SoC and UniCore ISA * * Copyright (C) 2001-2010 GUAN Xue-tao * * 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/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/gpio.h>#include <linux/stacktrace.h> #include <asm/cacheflush.h>#include <asm/processor.h>#include <asm/system.h>#include <asm/stacktrace.h> #include "setup.h" static const char * const processor_modes[] = {	"UK00", "UK01", "UK02", "UK03", "UK04", "UK05", "UK06", "UK07",	"UK08", "UK09", "UK0A", "UK0B", "UK0C", "UK0D", "UK0E", "UK0F",	"USER", "REAL", "INTR", "PRIV", "UK14", "UK15", "UK16", "ABRT",	"UK18", "UK19", "UK1A", "EXTN", "UK1C", "UK1D", "UK1E", "SUSR"}; /* * 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. */void cpu_idle(void){	/* endless idle loop with no priority at all */	while (1) {		tick_nohz_stop_sched_tick(1);		while (!need_resched()) {			local_irq_disable();			stop_critical_timings();			cpu_do_idle();			local_irq_enable();			start_critical_timings();		}		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){	gpio_set_value(GPO_SOFT_OFF, 0);} /* * Function pointers to optional machine specific functions */void (*pm_power_off)(void) = NULL; void machine_power_off(void){	if (pm_power_off)		pm_power_off();	machine_halt();} void machine_restart(char *cmd){	/* Disable interrupts first */	local_irq_disable(); 	/*	 * 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(reboot_mode); 	/* 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(); 	/*	 * Now handle reboot code.	 */	if (reboot_mode == 's') {		/* Jump into ROM at address 0xffff0000 */		cpu_reset(VECTORS_BASE);	} else {		writel(0x00002001, PM_PLLSYSCFG); /* cpu clk = 250M */		writel(0x00100800, PM_PLLDDRCFG); /* ddr clk =  44M */		writel(0x00002001, PM_PLLVGACFG); /* vga clk = 250M */ 		/* Use on-chip reset capability */		/* following instructions must be in one icache line */		__asm__ __volatile__(			"	.align 5\n\t"			"	stw	%1, [%0]\n\t"			"201:	ldw	r0, [%0]\n\t"			"	cmpsub.a	r0, #0\n\t"			"	bne	201b\n\t"			"	stw	%3, [%2]\n\t"			"	nop; nop; nop\n\t"			/* prefetch 3 instructions at most */			:			: "r" (PM_PMCR),			  "r" (PM_PMCR_CFBSYS | PM_PMCR_CFBDDR				| PM_PMCR_CFBVGA),			  "r" (RESETC_SWRR),			  "r" (RESETC_SWRR_SRB)			: "r0", "memory");	} 	/*	 * Whoops - the architecture was unable to reboot.	 * Tell the user!	 */	mdelay(1000);	printk(KERN_EMERG "Reboot failed -- System halted\n");	do { } while (1);} void __show_regs(struct pt_regs *regs){	unsigned long flags;	char buf[64]; 	printk(KERN_DEFAULT "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->UCreg_lr);	printk(KERN_DEFAULT "pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"	       "sp : %08lx  ip : %08lx  fp : %08lx\n",		regs->UCreg_pc, regs->UCreg_lr, regs->UCreg_asr,		regs->UCreg_sp, regs->UCreg_ip, regs->UCreg_fp);	printk(KERN_DEFAULT "r26: %08lx  r25: %08lx  r24: %08lx\n",		regs->UCreg_26, regs->UCreg_25,		regs->UCreg_24);	printk(KERN_DEFAULT "r23: %08lx  r22: %08lx  r21: %08lx  r20: %08lx\n",		regs->UCreg_23, regs->UCreg_22,		regs->UCreg_21, regs->UCreg_20);	printk(KERN_DEFAULT "r19: %08lx  r18: %08lx  r17: %08lx  r16: %08lx\n",		regs->UCreg_19, regs->UCreg_18,		regs->UCreg_17, regs->UCreg_16);	printk(KERN_DEFAULT "r15: %08lx  r14: %08lx  r13: %08lx  r12: %08lx\n",		regs->UCreg_15, regs->UCreg_14,		regs->UCreg_13, regs->UCreg_12);	printk(KERN_DEFAULT "r11: %08lx  r10: %08lx  r9 : %08lx  r8 : %08lx\n",		regs->UCreg_11, regs->UCreg_10,		regs->UCreg_09, regs->UCreg_08);	printk(KERN_DEFAULT "r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",		regs->UCreg_07, regs->UCreg_06,		regs->UCreg_05, regs->UCreg_04);	printk(KERN_DEFAULT "r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",		regs->UCreg_03, regs->UCreg_02,		regs->UCreg_01, regs->UCreg_00); 	flags = regs->UCreg_asr;	buf[0] = flags & PSR_S_BIT ? 'S' : 's';	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(KERN_DEFAULT "Flags: %s  INTR o%s  REAL o%s  Mode %s  Segment %s\n",		buf, interrupts_enabled(regs) ? "n" : "ff",		fast_interrupts_enabled(regs) ? "n" : "ff",		processor_modes[processor_mode(regs)],		segment_eq(get_fs(), get_ds()) ? "kernel" : "user");	{		unsigned int ctrl; 		buf[0] = '\0';		{			unsigned int transbase;			asm("movc %0, p0.c2, #0\n"			    : "=r" (transbase));			snprintf(buf, sizeof(buf), "  Table: %08x", transbase);		}		asm("movc %0, p0.c1, #0\n" : "=r" (ctrl)); 		printk(KERN_DEFAULT "Control: %08x%s\n", ctrl, buf);	}} void show_regs(struct pt_regs *regs){	printk(KERN_DEFAULT "\n");	printk(KERN_DEFAULT "Pid: %d, comm: %20s\n",			task_pid_nr(current), current->comm);	__show_regs(regs);	__backtrace();} /* * Free current thread data structures etc.. */void exit_thread(void){} 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));#ifdef CONFIG_UNICORE_FPU_F64	memset(&thread->fpstate, 0, sizeof(struct fp_state));#endif} 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->UCreg_00 = 0;	childregs->UCreg_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)		childregs->UCreg_16 = regs->UCreg_03; 	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, elf_fpregset_t *fp){	struct thread_info *thread = current_thread_info();	int used_math = thread->used_cp[1] | thread->used_cp[2]; #ifdef CONFIG_UNICORE_FPU_F64	if (used_math)		memcpy(fp, &thread->fpstate, sizeof(*fp));#endif	return used_math != 0;}EXPORT_SYMBOL(dump_fpu); /* * Shuffle the argument into the correct register before calling the * thread function.  r1 is the thread argument, r2 is the pointer to * the thread function, and r3 points to the exit function. */asm(".pushsection .text\n""	.align\n""	.type	kernel_thread_helper, #function\n""kernel_thread_helper:\n""	mov.a	asr, r7\n""	mov	r0, r4\n""	mov	lr, r6\n""	mov	pc, r5\n""	.size	kernel_thread_helper, . - kernel_thread_helper\n""	.popsection"); /* * 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.UCreg_04 = (unsigned long)arg;	regs.UCreg_05 = (unsigned long)fn;	regs.UCreg_06 = (unsigned long)do_exit;	regs.UCreg_07 = PRIV_MODE;	regs.UCreg_pc = (unsigned long)kernel_thread_helper;	regs.UCreg_asr = regs.UCreg_07 | 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;} /* * 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_ALWAYSDUMP | VM_RESERVED,				       NULL);} const char *arch_vma_name(struct vm_area_struct *vma){	return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;}