// SPDX-License-Identifier: GPL-2.0-or-later/* *    PARISC Architecture-dependent parts of process handling *    based on the work for i386 * *    Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org> *    Copyright (C) 2000 Martin K Petersen <mkp at mkp.net> *    Copyright (C) 2000 John Marvin <jsm at parisc-linux.org> *    Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org> *    Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org> *    Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org> *    Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com> *    Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org> *    Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org> *    Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org> *    Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org> *    Copyright (C) 2001-2014 Helge Deller <deller@gmx.de> *    Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org> */#include <linux/elf.h>#include <linux/errno.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/fs.h>#include <linux/cpu.h>#include <linux/module.h>#include <linux/personality.h>#include <linux/ptrace.h>#include <linux/reboot.h>#include <linux/sched.h>#include <linux/sched/debug.h>#include <linux/sched/task.h>#include <linux/sched/task_stack.h>#include <linux/slab.h>#include <linux/stddef.h>#include <linux/unistd.h>#include <linux/kallsyms.h>#include <linux/uaccess.h>#include <linux/rcupdate.h>#include <linux/random.h>#include <linux/nmi.h>#include <linux/sched/hotplug.h> #include <asm/io.h>#include <asm/asm-offsets.h>#include <asm/assembly.h>#include <asm/pdc.h>#include <asm/pdc_chassis.h>#include <asm/unwind.h>#include <asm/sections.h>#include <asm/cacheflush.h> #define COMMAND_GLOBAL  F_EXTEND(0xfffe0030)#define CMD_RESET       5       /* reset any module */ /*** The Wright Brothers and Gecko systems have a H/W problem** (Lasi...'nuf said) may cause a broadcast reset to lockup** the system. An HVERSION dependent PDC call was developed** to perform a "safe", platform specific broadcast reset instead** of kludging up all the code.**** Older machines which do not implement PDC_BROADCAST_RESET will** return (with an error) and the regular broadcast reset can be** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET** the PDC call will not return (the system will be reset).*/void machine_restart(char *cmd){#ifdef FASTBOOT_SELFTEST_SUPPORT	/*	 ** If user has modified the Firmware Selftest Bitmap,	 ** run the tests specified in the bitmap after the	 ** system is rebooted w/PDC_DO_RESET.	 **	 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"	 **	 ** Using "directed resets" at each processor with the MEM_TOC	 ** vector cleared will also avoid running destructive	 ** memory self tests. (Not implemented yet)	 */	if (ftc_bitmap) {		pdc_do_firm_test_reset(ftc_bitmap);	}#endif	/* set up a new led state on systems shipped with a LED State panel */	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);		/* "Normal" system reset */	pdc_do_reset(); 	/* Nope...box should reset with just CMD_RESET now */	gsc_writel(CMD_RESET, COMMAND_GLOBAL); 	/* Wait for RESET to lay us to rest. */	while (1) ; } /* * This routine is called from sys_reboot to actually turn off the * machine  */void machine_power_off(void){	/* Put the soft power button back under hardware control.	 * If the user had already pressed the power button, the	 * following call will immediately power off. */	pdc_soft_power_button(0);		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 	/* ipmi_poweroff may have been installed. */	do_kernel_power_off();			/* It seems we have no way to power the system off via	 * software. The user has to press the button himself. */ 	printk("Power off or press RETURN to reboot.\n"); 	/* prevent soft lockup/stalled CPU messages for endless loop. */	rcu_sysrq_start();	lockup_detector_soft_poweroff();	while (1) {		/* reboot if user presses RETURN key */		if (pdc_iodc_getc() == 13) {			printk("Rebooting...\n");			machine_restart(NULL);		}	}} void (*pm_power_off)(void);EXPORT_SYMBOL(pm_power_off); void machine_halt(void){	machine_power_off();} void flush_thread(void){	/* Only needs to handle fpu stuff or perf monitors.	** REVISIT: several arches implement a "lazy fpu state".	*/} /* * Idle thread support * * Detect when running on QEMU with SeaBIOS PDC Firmware and let * QEMU idle the host too. */ int running_on_qemu __ro_after_init;EXPORT_SYMBOL(running_on_qemu); /* * Called from the idle thread for the CPU which has been shutdown. */void __noreturn arch_cpu_idle_dead(void){#ifdef CONFIG_HOTPLUG_CPU	idle_task_exit(); 	local_irq_disable(); 	/* Tell the core that this CPU is now safe to dispose of. */	cpuhp_ap_report_dead(); 	/* Ensure that the cache lines are written out. */	flush_cache_all_local();	flush_tlb_all_local(NULL); 	/* Let PDC firmware put CPU into firmware idle loop. */	__pdc_cpu_rendezvous(); 	pr_warn("PDC does not provide rendezvous function.\n");#endif	while (1);} void __cpuidle arch_cpu_idle(void){	/* nop on real hardware, qemu will idle sleep. */	asm volatile("or %%r10,%%r10,%%r10\n":::);} static int __init parisc_idle_init(void){	if (!running_on_qemu)		cpu_idle_poll_ctrl(1); 	return 0;}arch_initcall(parisc_idle_init); /* * Copy architecture-specific thread state */intcopy_thread(struct task_struct *p, const struct kernel_clone_args *args){	unsigned long clone_flags = args->flags;	unsigned long usp = args->stack;	unsigned long tls = args->tls;	struct pt_regs *cregs = &(p->thread.regs);	void *stack = task_stack_page(p);		/* We have to use void * instead of a function pointer, because	 * function pointers aren't a pointer to the function on 64-bit.	 * Make them const so the compiler knows they live in .text */	extern void * const ret_from_kernel_thread;	extern void * const child_return; 	if (unlikely(args->fn)) {		/* kernel thread */		memset(cregs, 0, sizeof(struct pt_regs));		if (args->idle) /* idle thread */			return 0;		/* Must exit via ret_from_kernel_thread in order		 * to call schedule_tail()		 */		cregs->ksp = (unsigned long) stack + FRAME_SIZE + PT_SZ_ALGN;		cregs->kpc = (unsigned long) &ret_from_kernel_thread;		/*		 * Copy function and argument to be called from		 * ret_from_kernel_thread.		 */#ifdef CONFIG_64BIT		cregs->gr[27] = ((unsigned long *)args->fn)[3];		cregs->gr[26] = ((unsigned long *)args->fn)[2];#else		cregs->gr[26] = (unsigned long) args->fn;#endif		cregs->gr[25] = (unsigned long) args->fn_arg;	} else {		/* user thread */		/* usp must be word aligned.  This also prevents users from		 * passing in the value 1 (which is the signal for a special		 * return for a kernel thread) */		if (usp) {			usp = ALIGN(usp, 4);			if (likely(usp))				cregs->gr[30] = usp;		}		cregs->ksp = (unsigned long) stack + FRAME_SIZE;		cregs->kpc = (unsigned long) &child_return; 		/* Setup thread TLS area */		if (clone_flags & CLONE_SETTLS)			cregs->cr27 = tls;	} 	return 0;} unsigned long__get_wchan(struct task_struct *p){	struct unwind_frame_info info;	unsigned long ip;	int count = 0; 	/*	 * These bracket the sleeping functions..	 */ 	unwind_frame_init_from_blocked_task(&info, p);	do {		if (unwind_once(&info) < 0)			return 0;		if (task_is_running(p))                        return 0;		ip = info.ip;		if (!in_sched_functions(ip))			return ip;	} while (count++ < MAX_UNWIND_ENTRIES);	return 0;}