/* * Based on arch/arm/kernel/process.c * * Original Copyright (C) 1995  Linus Torvalds * Copyright (C) 1996-2000 Russell King - Converted to ARM. * Copyright (C) 2012 ARM Ltd. * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program.  If not, see <http://www.gnu.org/licenses/>. */ #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/personality.h>#include <linux/notifier.h> #include <asm/compat.h>#include <asm/cacheflush.h>#include <asm/fpsimd.h>#include <asm/mmu_context.h>#include <asm/processor.h>#include <asm/stacktrace.h> static void setup_restart(void){	/*	 * 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(); 	/* Clean and invalidate caches */	flush_cache_all(); 	/* Turn D-cache off */	cpu_cache_off(); 	/* Push out any further dirty data, and ensure cache is empty */	flush_cache_all();} void soft_restart(unsigned long addr){	setup_restart();	cpu_reset(addr);} /* * Function pointers to optional machine specific functions */void (*pm_power_off)(void);EXPORT_SYMBOL_GPL(pm_power_off); void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);EXPORT_SYMBOL_GPL(arm_pm_restart); void arch_cpu_idle_prepare(void){	local_fiq_enable();} /* * This is our default idle handler. */void arch_cpu_idle(void){	/*	 * This should do all the clock switching and wait for interrupt	 * tricks	 */	cpu_do_idle();	local_irq_enable();} #ifdef CONFIG_HOTPLUG_CPUvoid arch_cpu_idle_dead(void){       cpu_die();}#endif 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(); 	/* Disable interrupts first */	local_irq_disable();	local_fiq_disable(); 	/* Now call the architecture specific reboot code. */	if (arm_pm_restart)		arm_pm_restart(reboot_mode, cmd); 	/*	 * Whoops - the architecture was unable to reboot.	 */	printk("Reboot failed -- System halted\n");	while (1);} void __show_regs(struct pt_regs *regs){	int i, top_reg;	u64 lr, sp; 	if (compat_user_mode(regs)) {		lr = regs->compat_lr;		sp = regs->compat_sp;		top_reg = 12;	} else {		lr = regs->regs[30];		sp = regs->sp;		top_reg = 29;	} 	show_regs_print_info(KERN_DEFAULT);	print_symbol("PC is at %s\n", instruction_pointer(regs));	print_symbol("LR is at %s\n", lr);	printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",	       regs->pc, lr, regs->pstate);	printk("sp : %016llx\n", sp);	for (i = top_reg; i >= 0; i--) {		printk("x%-2d: %016llx ", i, regs->regs[i]);		if (i % 2 == 0)			printk("\n");	}	printk("\n");} void show_regs(struct pt_regs * regs){	printk("\n");	__show_regs(regs);} /* * Free current thread data structures etc.. */void exit_thread(void){} void flush_thread(void){	fpsimd_flush_thread();	flush_ptrace_hw_breakpoint(current);} void release_thread(struct task_struct *dead_task){} int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src){	fpsimd_save_state(&current->thread.fpsimd_state);	*dst = *src;	return 0;} 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 *childregs = task_pt_regs(p);	unsigned long tls = p->thread.tp_value; 	memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context)); 	if (likely(!(p->flags & PF_KTHREAD))) {		*childregs = *current_pt_regs();		childregs->regs[0] = 0;		if (is_compat_thread(task_thread_info(p))) {			if (stack_start)				childregs->compat_sp = stack_start;		} else {			/*			 * Read the current TLS pointer from tpidr_el0 as it may be			 * out-of-sync with the saved value.			 */			asm("mrs %0, tpidr_el0" : "=r" (tls));			if (stack_start) {				/* 16-byte aligned stack mandatory on AArch64 */				if (stack_start & 15)					return -EINVAL;				childregs->sp = stack_start;			}		}		/*		 * If a TLS pointer was passed to clone (4th argument), use it		 * for the new thread.		 */		if (clone_flags & CLONE_SETTLS)			tls = childregs->regs[3];	} else {		memset(childregs, 0, sizeof(struct pt_regs));		childregs->pstate = PSR_MODE_EL1h;		p->thread.cpu_context.x19 = stack_start;		p->thread.cpu_context.x20 = stk_sz;	}	p->thread.cpu_context.pc = (unsigned long)ret_from_fork;	p->thread.cpu_context.sp = (unsigned long)childregs;	p->thread.tp_value = tls; 	ptrace_hw_copy_thread(p); 	return 0;} static void tls_thread_switch(struct task_struct *next){	unsigned long tpidr, tpidrro; 	if (!is_compat_task()) {		asm("mrs %0, tpidr_el0" : "=r" (tpidr));		current->thread.tp_value = tpidr;	} 	if (is_compat_thread(task_thread_info(next))) {		tpidr = 0;		tpidrro = next->thread.tp_value;	} else {		tpidr = next->thread.tp_value;		tpidrro = 0;	} 	asm(	"	msr	tpidr_el0, %0\n"	"	msr	tpidrro_el0, %1"	: : "r" (tpidr), "r" (tpidrro));} /* * Thread switching. */struct task_struct *__switch_to(struct task_struct *prev,				struct task_struct *next){	struct task_struct *last; 	fpsimd_thread_switch(next);	tls_thread_switch(next);	hw_breakpoint_thread_switch(next);	contextidr_thread_switch(next); 	/*	 * Complete any pending TLB or cache maintenance on this CPU in case	 * the thread migrates to a different CPU.	 */	dsb(); 	/* the actual thread switch */	last = cpu_switch_to(prev, next); 	return last;} 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.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_align_stack(unsigned long sp){	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)		sp -= get_random_int() & ~PAGE_MASK;	return sp & ~0xf;} static unsigned long randomize_base(unsigned long base){	unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;	return randomize_range(base, range_end, 0) ? : base;} unsigned long arch_randomize_brk(struct mm_struct *mm){	return randomize_base(mm->brk);} unsigned long randomize_et_dyn(unsigned long base){	return randomize_base(base);}