LXR linux/arch/h8300/kernel/process.c

   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#include <asm/pgtable.h>
  49
  50void (*pm_power_off)(void) = NULL;
  51EXPORT_SYMBOL(pm_power_off);
  52
  53asmlinkage void ret_from_fork(void);
  54asmlinkage void ret_from_kernel_thread(void);
  55
  56/*
  57 * The idle loop on an H8/300..
  58 */
  59void arch_cpu_idle(void)
  60{
  61        local_irq_enable();
  62        __asm__("sleep");
  63}
  64
  65void machine_restart(char *__unused)
  66{
  67        local_irq_disable();
  68        __asm__("jmp @@0");
  69}
  70
  71void machine_halt(void)
  72{
  73        local_irq_disable();
  74        __asm__("sleep");
  75        for (;;)
  76                ;
  77}
  78
  79void machine_power_off(void)
  80{
  81        local_irq_disable();
  82        __asm__("sleep");
  83        for (;;)
  84                ;
  85}
  86
  87void show_regs(struct pt_regs *regs)
  88{
  89        show_regs_print_info(KERN_DEFAULT);
  90
  91        pr_notice("\n");
  92        pr_notice("PC: %08lx  Status: %02x\n",
  93               regs->pc, regs->ccr);
  94        pr_notice("ORIG_ER0: %08lx ER0: %08lx ER1: %08lx\n",
  95               regs->orig_er0, regs->er0, regs->er1);
  96        pr_notice("ER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx\n",
  97               regs->er2, regs->er3, regs->er4, regs->er5);
  98        pr_notice("ER6' %08lx ", regs->er6);
  99        if (user_mode(regs))
 100                printk("USP: %08lx\n", rdusp());
 101        else
 102                printk("\n");
 103}
 104
 105void flush_thread(void)
 106{
 107}
 108
 109int copy_thread(unsigned long clone_flags,
 110                unsigned long usp, unsigned long topstk,
 111                struct task_struct *p)
 112{
 113        struct pt_regs *childregs;
 114
 115        childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
 116
 117        if (unlikely(p->flags & PF_KTHREAD)) {
 118                memset(childregs, 0, sizeof(struct pt_regs));
 119                childregs->retpc = (unsigned long) ret_from_kernel_thread;
 120                childregs->er4 = topstk; /* arg */
 121                childregs->er5 = usp; /* fn */
 122        }  else {
 123                *childregs = *current_pt_regs();
 124                childregs->er0 = 0;
 125                childregs->retpc = (unsigned long) ret_from_fork;
 126                p->thread.usp = usp ?: rdusp();
 127        }
 128        p->thread.ksp = (unsigned long)childregs;
 129
 130        return 0;
 131}
 132
 133unsigned long get_wchan(struct task_struct *p)
 134{
 135        unsigned long fp, pc;
 136        unsigned long stack_page;
 137        int count = 0;
 138
 139        if (!p || p == current || p->state == TASK_RUNNING)
 140                return 0;
 141
 142        stack_page = (unsigned long)p;
 143        fp = ((struct pt_regs *)p->thread.ksp)->er6;
 144        do {
 145                if (fp < stack_page+sizeof(struct thread_info) ||
 146                    fp >= 8184+stack_page)
 147                        return 0;
 148                pc = ((unsigned long *)fp)[1];
 149                if (!in_sched_functions(pc))
 150                        return pc;
 151                fp = *(unsigned long *) fp;
 152        } while (count++ < 16);
 153        return 0;
 154}
 155
 156/* generic sys_clone is not enough registers */
 157asmlinkage int sys_clone(unsigned long __user *args)
 158{
 159        unsigned long clone_flags;
 160        unsigned long  newsp;
 161        uintptr_t parent_tidptr;
 162        uintptr_t child_tidptr;
 163
 164        get_user(clone_flags, &args[0]);
 165        get_user(newsp, &args[1]);
 166        get_user(parent_tidptr, &args[2]);
 167        get_user(child_tidptr, &args[3]);
 168        return do_fork(clone_flags, newsp, 0,
 169                       (int __user *)parent_tidptr, (int __user *)child_tidptr);
 170}
 171