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
  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        raw_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 | PF_IO_WORKER))) {
 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 kernel_clone(&kargs);
 176}
 177