1/*
  2 *  linux/arch/h8300/kernel/process.c
  3 *
  4 * Yoshinori Sato <ysato@users.sourceforge.jp>
  5 *
  6 *  Based on:
  7 *
  8 *  linux/arch/m68knommu/kernel/process.c
  9 *
 10 *  Copyright (C) 1998  D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
 11 *                      Kenneth Albanowski <kjahds@kjahds.com>,
 12 *                      The Silver Hammer Group, Ltd.
 13 *
 14 *  linux/arch/m68k/kernel/process.c
 15 *
 16 *  Copyright (C) 1995  Hamish Macdonald
 17 *
 18 *  68060 fixes by Jesper Skov
 19 */
 20
 21/*
 22 * This file handles the architecture-dependent parts of process handling..
 23 */
 24
 25#include <linux/errno.h>
 26#include <linux/module.h>
 27#include <linux/sched.h>
 28#include <linux/kernel.h>
 29#include <linux/mm.h>
 30#include <linux/smp.h>
 31#include <linux/stddef.h>
 32#include <linux/unistd.h>
 33#include <linux/ptrace.h>
 34#include <linux/user.h>
 35#include <linux/interrupt.h>
 36#include <linux/reboot.h>
 37#include <linux/fs.h>
 38#include <linux/slab.h>
 39#include <linux/rcupdate.h>
 40
 41#include <asm/uaccess.h>
 42#include <asm/traps.h>
 43#include <asm/setup.h>
 44#include <asm/pgtable.h>
 45
 46void (*pm_power_off)(void) = NULL;
 47EXPORT_SYMBOL(pm_power_off);
 48
 49asmlinkage void ret_from_fork(void);
 50asmlinkage void ret_from_kernel_thread(void);
 51
 52/*
 53 * The idle loop on an H8/300..
 54 */
 55void arch_cpu_idle(void)
 56{
 57	local_irq_enable();
 58	__asm__("sleep");
 59}
 60
 61void machine_restart(char *__unused)
 62{
 63	local_irq_disable();
 64	__asm__("jmp @@0");
 65}
 66
 67void machine_halt(void)
 68{
 69	local_irq_disable();
 70	__asm__("sleep");
 71	for (;;)
 72		;
 73}
 74
 75void machine_power_off(void)
 76{
 77	local_irq_disable();
 78	__asm__("sleep");
 79	for (;;)
 80		;
 81}
 82
 83void show_regs(struct pt_regs *regs)
 84{
 85	show_regs_print_info(KERN_DEFAULT);
 86
 87	pr_notice("\n");
 88	pr_notice("PC: %08lx  Status: %02x\n",
 89	       regs->pc, regs->ccr);
 90	pr_notice("ORIG_ER0: %08lx ER0: %08lx ER1: %08lx\n",
 91	       regs->orig_er0, regs->er0, regs->er1);
 92	pr_notice("ER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx\n",
 93	       regs->er2, regs->er3, regs->er4, regs->er5);
 94	pr_notice("ER6' %08lx ", regs->er6);
 95	if (user_mode(regs))
 96		printk("USP: %08lx\n", rdusp());
 97	else
 98		printk("\n");
 99}
100
101void flush_thread(void)
102{
103}
104
105int copy_thread(unsigned long clone_flags,
106		unsigned long usp, unsigned long topstk,
107		struct task_struct *p)
108{
109	struct pt_regs *childregs;
110
111	childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
112
113	if (unlikely(p->flags & PF_KTHREAD)) {
114		memset(childregs, 0, sizeof(struct pt_regs));
115		childregs->retpc = (unsigned long) ret_from_kernel_thread;
116		childregs->er4 = topstk; /* arg */
117		childregs->er5 = usp; /* fn */
118	}  else {
119		*childregs = *current_pt_regs();
120		childregs->er0 = 0;
121		childregs->retpc = (unsigned long) ret_from_fork;
122		p->thread.usp = usp ?: rdusp();
123	}
124	p->thread.ksp = (unsigned long)childregs;
125
126	return 0;
127}
128
129unsigned long thread_saved_pc(struct task_struct *tsk)
130{
131	return ((struct pt_regs *)tsk->thread.esp0)->pc;
132}
133
134unsigned long get_wchan(struct task_struct *p)
135{
136	unsigned long fp, pc;
137	unsigned long stack_page;
138	int count = 0;
139
140	if (!p || p == current || p->state == TASK_RUNNING)
141		return 0;
142
143	stack_page = (unsigned long)p;
144	fp = ((struct pt_regs *)p->thread.ksp)->er6;
145	do {
146		if (fp < stack_page+sizeof(struct thread_info) ||
147		    fp >= 8184+stack_page)
148			return 0;
149		pc = ((unsigned long *)fp)[1];
150		if (!in_sched_functions(pc))
151			return pc;
152		fp = *(unsigned long *) fp;
153	} while (count++ < 16);
154	return 0;
155}
156
157/* generic sys_clone is not enough registers */
158asmlinkage int sys_clone(unsigned long __user *args)
159{
160	unsigned long clone_flags;
161	unsigned long  newsp;
162	uintptr_t parent_tidptr;
163	uintptr_t child_tidptr;
164
165	get_user(clone_flags, &args[0]);
166	get_user(newsp, &args[1]);
167	get_user(parent_tidptr, &args[2]);
168	get_user(child_tidptr, &args[3]);
169	return do_fork(clone_flags, newsp, 0,
170		       (int __user *)parent_tidptr, (int __user *)child_tidptr);
171}