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/smp_lock.h>
  32 #include <linux/stddef.h>
  33 #include <linux/unistd.h>
  34 #include <linux/ptrace.h>
  35 #include <linux/slab.h>
  36 #include <linux/user.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/reboot.h>
  39 #include <linux/fs.h>
  40
  41 #include <asm/uaccess.h>
  42 #include <asm/system.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
  52 /*
  53  * The idle loop on an H8/300..
  54  */
  55 #if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM)
  56 static void default_idle(void)
  57 {
  58         local_irq_disable();
  59         if (!need_resched()) {
  60                 local_irq_enable();
  61                 /* XXX: race here! What if need_resched() gets set now? */
  62                 __asm__("sleep");
  63         } else
  64                 local_irq_enable();
  65 }
  66 #else
  67 static void default_idle(void)
  68 {
  69         cpu_relax();
  70 }
  71 #endif
  72 void (*idle)(void) = default_idle;
  73
  74 /*
  75  * The idle thread. There's no useful work to be
  76  * done, so just try to conserve power and have a
  77  * low exit latency (ie sit in a loop waiting for
  78  * somebody to say that they'd like to reschedule)
  79  */
  80 void cpu_idle(void)
  81 {
  82         while (1) {
  83                 while (!need_resched())
  84                         idle();
  85                 preempt_enable_no_resched();
  86                 schedule();
  87                 preempt_disable();
  88         }
  89 }
  90
  91 void machine_restart(char * __unused)
  92 {
  93         local_irq_disable();
  94         __asm__("jmp @@0");
  95 }
  96
  97 void machine_halt(void)
  98 {
  99         local_irq_disable();
 100         __asm__("sleep");
 101         for (;;);
 102 }
 103
 104 void machine_power_off(void)
 105 {
 106         local_irq_disable();
 107         __asm__("sleep");
 108         for (;;);
 109 }
 110
 111 void show_regs(struct pt_regs * regs)
 112 {
 113         printk("\nPC: %08lx  Status: %02x",
 114                regs->pc, regs->ccr);
 115         printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
 116                regs->orig_er0, regs->er0, regs->er1);
 117         printk("\nER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx",
 118                regs->er2, regs->er3, regs->er4, regs->er5);
 119         printk("\nER6' %08lx ",regs->er6);
 120         if (user_mode(regs))
 121                 printk("USP: %08lx\n", rdusp());
 122         else
 123                 printk("\n");
 124 }
 125
 126 /*
 127  * Create a kernel thread
 128  */
 129 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 130 {
 131         long retval;
 132         long clone_arg;
 133         mm_segment_t fs;
 134
 135         fs = get_fs();
 136         set_fs (KERNEL_DS);
 137         clone_arg = flags | CLONE_VM;
 138         __asm__("mov.l sp,er3\n\t"
 139                 "sub.l er2,er2\n\t"
 140                 "mov.l %2,er1\n\t"
 141                 "mov.l %1,er0\n\t"
 142                 "trapa #0\n\t"
 143                 "cmp.l sp,er3\n\t"
 144                 "beq 1f\n\t"
 145                 "mov.l %4,er0\n\t"
 146                 "mov.l %3,er1\n\t"
 147                 "jsr @er1\n\t"
 148                 "mov.l %5,er0\n\t"
 149                 "trapa #0\n"
 150                 "1:\n\t"
 151                 "mov.l er0,%0"
 152                 :"=r"(retval)
 153                 :"i"(__NR_clone),"g"(clone_arg),"g"(fn),"g"(arg),"i"(__NR_exit)
 154                 :"er0","er1","er2","er3");
 155         set_fs (fs);
 156         return retval;
 157 }
 158
 159 void flush_thread(void)
 160 {
 161 }
 162
 163 /*
 164  * "h8300_fork()".. By the time we get here, the
 165  * non-volatile registers have also been saved on the
 166  * stack. We do some ugly pointer stuff here.. (see
 167  * also copy_thread)
 168  */
 169
 170 asmlinkage int h8300_fork(struct pt_regs *regs)
 171 {
 172         return -EINVAL;
 173 }
 174
 175 asmlinkage int h8300_vfork(struct pt_regs *regs)
 176 {
 177         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 178 }
 179
 180 asmlinkage int h8300_clone(struct pt_regs *regs)
 181 {
 182         unsigned long clone_flags;
 183         unsigned long newsp;
 184
 185         /* syscall2 puts clone_flags in er1 and usp in er2 */
 186         clone_flags = regs->er1;
 187         newsp = regs->er2;
 188         if (!newsp)
 189                 newsp  = rdusp();
 190         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 191
 192 }
 193
 194 int copy_thread(unsigned long clone_flags,
 195                 unsigned long usp, unsigned long topstk,
 196                  struct task_struct * p, struct pt_regs * regs)
 197 {
 198         struct pt_regs * childregs;
 199
 200         childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
 201
 202         *childregs = *regs;
 203         childregs->retpc = (unsigned long) ret_from_fork;
 204         childregs->er0 = 0;
 205
 206         p->thread.usp = usp;
 207         p->thread.ksp = (unsigned long)childregs;
 208
 209         return 0;
 210 }
 211
 212 /*
 213  * sys_execve() executes a new program.
 214  */
 215 asmlinkage int sys_execve(char *name, char **argv, char **envp,int dummy,...)
 216 {
 217         int error;
 218         char * filename;
 219         struct pt_regs *regs = (struct pt_regs *) ((unsigned char *)&dummy-4);
 220
 221         lock_kernel();
 222         filename = getname(name);
 223         error = PTR_ERR(filename);
 224         if (IS_ERR(filename))
 225                 goto out;
 226         error = do_execve(filename, argv, envp, regs);
 227         putname(filename);
 228 out:
 229         unlock_kernel();
 230         return error;
 231 }
 232
 233 unsigned long thread_saved_pc(struct task_struct *tsk)
 234 {
 235         return ((struct pt_regs *)tsk->thread.esp0)->pc;
 236 }
 237
 238 unsigned long get_wchan(struct task_struct *p)
 239 {
 240         unsigned long fp, pc;
 241         unsigned long stack_page;
 242         int count = 0;
 243         if (!p || p == current || p->state == TASK_RUNNING)
 244                 return 0;
 245
 246         stack_page = (unsigned long)p;
 247         fp = ((struct pt_regs *)p->thread.ksp)->er6;
 248         do {
 249                 if (fp < stack_page+sizeof(struct thread_info) ||
 250                     fp >= 8184+stack_page)
 251                         return 0;
 252                 pc = ((unsigned long *)fp)[1];
 253                 if (!in_sched_functions(pc))
 254                         return pc;
 255                 fp = *(unsigned long *) fp;
 256         } while (count++ < 16);
 257         return 0;
 258 }