1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/arch/h8300/kernel/process.c
  4 *
  5 * Yoshinori Sato <ysato@users.sourceforge.jp>
  6 *
  7 *  Based on:
  8 *
  9 *  linux/arch/m68knommu/kernel/process.c
 10 *
 11 *  Copyright (C) 1998  D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
 12 *                      Kenneth Albanowski <kjahds@kjahds.com>,
 13 *                      The Silver Hammer Group, Ltd.
 14 *
 15 *  linux/arch/m68k/kernel/process.c
 16 *
 17 *  Copyright (C) 1995  Hamish Macdonald
 18 *
 19 *  68060 fixes by Jesper Skov
 20 */
 21
 22/*
 23 * This file handles the architecture-dependent parts of process handling..
 24 */
 25
 26#include <linux/errno.h>
 27#include <linux/module.h>
 28#include <linux/sched.h>
 29#include <linux/sched/debug.h>
 30#include <linux/sched/task.h>
 31#include <linux/sched/task_stack.h>
 32#include <linux/kernel.h>
 33#include <linux/mm.h>
 34#include <linux/smp.h>
 35#include <linux/stddef.h>
 36#include <linux/unistd.h>
 37#include <linux/ptrace.h>
 38#include <linux/user.h>
 39#include <linux/interrupt.h>
 40#include <linux/reboot.h>
 41#include <linux/fs.h>
 42#include <linux/slab.h>
 43#include <linux/rcupdate.h>
 44
 45#include <linux/uaccess.h>
 46#include <asm/traps.h>
 47#include <asm/setup.h>
 48
 49void (*pm_power_off)(void) = NULL;
 50EXPORT_SYMBOL(pm_power_off);
 51
 52asmlinkage void ret_from_fork(void);
 53asmlinkage void ret_from_kernel_thread(void);
 54
 55/*
 56 * The idle loop on an H8/300..
 57 */
 58void arch_cpu_idle(void)
 59{
 60	local_irq_enable();
 61	__asm__("sleep");
 62}
 63
 64void machine_restart(char *__unused)
 65{
 66	local_irq_disable();
 67	__asm__("jmp @@0");
 68}
 69
 70void machine_halt(void)
 71{
 72	local_irq_disable();
 73	__asm__("sleep");
 74	for (;;)
 75		;
 76}
 77
 78void machine_power_off(void)
 79{
 80	local_irq_disable();
 81	__asm__("sleep");
 82	for (;;)
 83		;
 84}
 85
 86void show_regs(struct pt_regs *regs)
 87{
 88	show_regs_print_info(KERN_DEFAULT);
 89
 90	pr_notice("\n");
 91	pr_notice("PC: %08lx  Status: %02x\n",
 92	       regs->pc, regs->ccr);
 93	pr_notice("ORIG_ER0: %08lx ER0: %08lx ER1: %08lx\n",
 94	       regs->orig_er0, regs->er0, regs->er1);
 95	pr_notice("ER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx\n",
 96	       regs->er2, regs->er3, regs->er4, regs->er5);
 97	pr_notice("ER6' %08lx ", regs->er6);
 98	if (user_mode(regs))
 99		printk("USP: %08lx\n", rdusp());
100	else
101		printk("\n");
102}
103
104void flush_thread(void)
105{
106}
107
108int copy_thread(unsigned long clone_flags, unsigned long usp,
109		unsigned long topstk, struct task_struct *p, unsigned long tls)
110{
111	struct pt_regs *childregs;
112
113	childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
114
115	if (unlikely(p->flags & PF_KTHREAD)) {
116		memset(childregs, 0, sizeof(struct pt_regs));
117		childregs->retpc = (unsigned long) ret_from_kernel_thread;
118		childregs->er4 = topstk; /* arg */
119		childregs->er5 = usp; /* fn */
120	}  else {
121		*childregs = *current_pt_regs();
122		childregs->er0 = 0;
123		childregs->retpc = (unsigned long) ret_from_fork;
124		p->thread.usp = usp ?: rdusp();
125	}
126	p->thread.ksp = (unsigned long)childregs;
127
128	return 0;
129}
130
131unsigned long get_wchan(struct task_struct *p)
132{
133	unsigned long fp, pc;
134	unsigned long stack_page;
135	int count = 0;
136
137	if (!p || p == current || p->state == TASK_RUNNING)
138		return 0;
139
140	stack_page = (unsigned long)p;
141	fp = ((struct pt_regs *)p->thread.ksp)->er6;
142	do {
143		if (fp < stack_page+sizeof(struct thread_info) ||
144		    fp >= 8184+stack_page)
145			return 0;
146		pc = ((unsigned long *)fp)[1];
147		if (!in_sched_functions(pc))
148			return pc;
149		fp = *(unsigned long *) fp;
150	} while (count++ < 16);
151	return 0;
152}
153
154/* generic sys_clone is not enough registers */
155asmlinkage int sys_clone(unsigned long __user *args)
156{
157	unsigned long clone_flags;
158	unsigned long  newsp;
159	uintptr_t parent_tidptr;
160	uintptr_t child_tidptr;
161	struct kernel_clone_args kargs = {};
162
163	get_user(clone_flags, &args[0]);
164	get_user(newsp, &args[1]);
165	get_user(parent_tidptr, &args[2]);
166	get_user(child_tidptr, &args[3]);
167
168	kargs.flags		= (lower_32_bits(clone_flags) & ~CSIGNAL);
169	kargs.pidfd		= (int __user *)parent_tidptr;
170	kargs.child_tid		= (int __user *)child_tidptr;
171	kargs.parent_tid	= (int __user *)parent_tidptr;
172	kargs.exit_signal	= (lower_32_bits(clone_flags) & CSIGNAL);
173	kargs.stack		= newsp;
174
175	return _do_fork(&kargs);
176}