arch/h8300/kernel/process.c

   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/sched/debug.h>
  29 #include <linux/kernel.h>
  30 #include <linux/mm.h>
  31 #include <linux/smp.h>
  32 #include <linux/stddef.h>
  33 #include <linux/unistd.h>
  34 #include <linux/ptrace.h>
  35 #include <linux/user.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/reboot.h>
  38 #include <linux/fs.h>
  39 #include <linux/slab.h>
  40 #include <linux/rcupdate.h>
  41
  42 #include <linux/uaccess.h>
  43 #include <asm/traps.h>
  44 #include <asm/setup.h>
  45 #include <asm/pgtable.h>
  46
  47 void (*pm_power_off)(void) = NULL;
  48 EXPORT_SYMBOL(pm_power_off);
  49
  50 asmlinkage void ret_from_fork(void);
  51 asmlinkage void ret_from_kernel_thread(void);
  52
  53 /*
  54  * The idle loop on an H8/300..
  55  */
  56 void arch_cpu_idle(void)
  57 {
  58         local_irq_enable();
  59         __asm__("sleep");
  60 }
  61
  62 void machine_restart(char *__unused)
  63 {
  64         local_irq_disable();
  65         __asm__("jmp @@0");
  66 }
  67
  68 void machine_halt(void)
  69 {
  70         local_irq_disable();
  71         __asm__("sleep");
  72         for (;;)
  73                 ;
  74 }
  75
  76 void machine_power_off(void)
  77 {
  78         local_irq_disable();
  79         __asm__("sleep");
  80         for (;;)
  81                 ;
  82 }
  83
  84 void show_regs(struct pt_regs *regs)
  85 {
  86         show_regs_print_info(KERN_DEFAULT);
  87
  88         pr_notice("\n");
  89         pr_notice("PC: %08lx  Status: %02x\n",
  90                regs->pc, regs->ccr);
  91         pr_notice("ORIG_ER0: %08lx ER0: %08lx ER1: %08lx\n",
  92                regs->orig_er0, regs->er0, regs->er1);
  93         pr_notice("ER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx\n",
  94                regs->er2, regs->er3, regs->er4, regs->er5);
  95         pr_notice("ER6' %08lx ", regs->er6);
  96         if (user_mode(regs))
  97                 printk("USP: %08lx\n", rdusp());
  98         else
  99                 printk("\n");
 100 }
 101
 102 void flush_thread(void)
 103 {
 104 }
 105
 106 int copy_thread(unsigned long clone_flags,
 107                 unsigned long usp, unsigned long topstk,
 108                 struct task_struct *p)
 109 {
 110         struct pt_regs *childregs;
 111
 112         childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
 113
 114         if (unlikely(p->flags & PF_KTHREAD)) {
 115                 memset(childregs, 0, sizeof(struct pt_regs));
 116                 childregs->retpc = (unsigned long) ret_from_kernel_thread;
 117                 childregs->er4 = topstk; /* arg */
 118                 childregs->er5 = usp; /* fn */
 119         }  else {
 120                 *childregs = *current_pt_regs();
 121                 childregs->er0 = 0;
 122                 childregs->retpc = (unsigned long) ret_from_fork;
 123                 p->thread.usp = usp ?: rdusp();
 124         }
 125         p->thread.ksp = (unsigned long)childregs;
 126
 127         return 0;
 128 }
 129
 130 unsigned long thread_saved_pc(struct task_struct *tsk)
 131 {
 132         return ((struct pt_regs *)tsk->thread.esp0)->pc;
 133 }
 134
 135 unsigned long get_wchan(struct task_struct *p)
 136 {
 137         unsigned long fp, pc;
 138         unsigned long stack_page;
 139         int count = 0;
 140
 141         if (!p || p == current || p->state == TASK_RUNNING)
 142                 return 0;
 143
 144         stack_page = (unsigned long)p;
 145         fp = ((struct pt_regs *)p->thread.ksp)->er6;
 146         do {
 147                 if (fp < stack_page+sizeof(struct thread_info) ||
 148                     fp >= 8184+stack_page)
 149                         return 0;
 150                 pc = ((unsigned long *)fp)[1];
 151                 if (!in_sched_functions(pc))
 152                         return pc;
 153                 fp = *(unsigned long *) fp;
 154         } while (count++ < 16);
 155         return 0;
 156 }
 157
 158 /* generic sys_clone is not enough registers */
 159 asmlinkage int sys_clone(unsigned long __user *args)
 160 {
 161         unsigned long clone_flags;
 162         unsigned long  newsp;
 163         uintptr_t parent_tidptr;
 164         uintptr_t child_tidptr;
 165
 166         get_user(clone_flags, &args[0]);
 167         get_user(newsp, &args[1]);
 168         get_user(parent_tidptr, &args[2]);
 169         get_user(child_tidptr, &args[3]);
 170         return do_fork(clone_flags, newsp, 0,
 171                        (int __user *)parent_tidptr, (int __user *)child_tidptr);
 172 }