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/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
  46 void (*pm_power_off)(void) = NULL;
  47 EXPORT_SYMBOL(pm_power_off);
  48
  49 asmlinkage void ret_from_fork(void);
  50 asmlinkage void ret_from_kernel_thread(void);
  51
  52 /*
  53  * The idle loop on an H8/300..
  54  */
  55 #if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM)
  56 void arch_cpu_idle(void)
  57 {
  58         local_irq_enable();
  59         /* XXX: race here! What if need_resched() gets set now? */
  60         __asm__("sleep");
  61 }
  62 #endif
  63
  64 void machine_restart(char * __unused)
  65 {
  66         local_irq_disable();
  67         __asm__("jmp @@0");
  68 }
  69
  70 void machine_halt(void)
  71 {
  72         local_irq_disable();
  73         __asm__("sleep");
  74         for (;;);
  75 }
  76
  77 void machine_power_off(void)
  78 {
  79         local_irq_disable();
  80         __asm__("sleep");
  81         for (;;);
  82 }
  83
  84 void show_regs(struct pt_regs * regs)
  85 {
  86         printk("\nPC: %08lx  Status: %02x",
  87                regs->pc, regs->ccr);
  88         printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
  89                regs->orig_er0, regs->er0, regs->er1);
  90         printk("\nER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx",
  91                regs->er2, regs->er3, regs->er4, regs->er5);
  92         printk("\nER6' %08lx ",regs->er6);
  93         if (user_mode(regs))
  94                 printk("USP: %08lx\n", rdusp());
  95         else
  96                 printk("\n");
  97 }
  98
  99 void flush_thread(void)
 100 {
 101 }
 102
 103 int copy_thread(unsigned long clone_flags,
 104                 unsigned long usp, unsigned long topstk,
 105                  struct task_struct * p)
 106 {
 107         struct pt_regs * childregs;
 108
 109         childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
 110
 111         if (unlikely(p->flags & PF_KTHREAD)) {
 112                 memset(childregs, 0, sizeof(struct pt_regs));
 113                 childregs->retpc = (unsigned long) ret_from_kernel_thread;
 114                 childregs->er4 = topstk; /* arg */
 115                 childregs->er5 = usp; /* fn */
 116                 p->thread.ksp = (unsigned long)childregs;
 117         }
 118         *childregs = *current_pt_regs();
 119         childregs->retpc = (unsigned long) ret_from_fork;
 120         childregs->er0 = 0;
 121         p->thread.usp = usp ?: rdusp();
 122         p->thread.ksp = (unsigned long)childregs;
 123
 124         return 0;
 125 }
 126
 127 unsigned long thread_saved_pc(struct task_struct *tsk)
 128 {
 129         return ((struct pt_regs *)tsk->thread.esp0)->pc;
 130 }
 131
 132 unsigned long get_wchan(struct task_struct *p)
 133 {
 134         unsigned long fp, pc;
 135         unsigned long stack_page;
 136         int count = 0;
 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 }