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/a.out.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/reboot.h>
  40 #include <linux/fs.h>
  41
  42 #include <asm/uaccess.h>
  43 #include <asm/system.h>
  44 #include <asm/traps.h>
  45 #include <asm/setup.h>
  46 #include <asm/pgtable.h>
  47
  48 void (*pm_power_off)(void) = NULL;
  49 EXPORT_SYMBOL(pm_power_off);
  50
  51 asmlinkage void ret_from_fork(void);
  52
  53 /*
  54  * The idle loop on an H8/300..
  55  */
  56 #if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM)
  57 static void default_idle(void)
  58 {
  59         local_irq_disable();
  60         if (!need_resched()) {
  61                 local_irq_enable();
  62                 /* XXX: race here! What if need_resched() gets set now? */
  63                 __asm__("sleep");
  64         } else
  65                 local_irq_enable();
  66 }
  67 #else
  68 static void default_idle(void)
  69 {
  70         cpu_relax();
  71 }
  72 #endif
  73 void (*idle)(void) = default_idle;
  74
  75 /*
  76  * The idle thread. There's no useful work to be
  77  * done, so just try to conserve power and have a
  78  * low exit latency (ie sit in a loop waiting for
  79  * somebody to say that they'd like to reschedule)
  80  */
  81 void cpu_idle(void)
  82 {
  83         while (1) {
  84                 while (!need_resched())
  85                         idle();
  86                 preempt_enable_no_resched();
  87                 schedule();
  88                 preempt_disable();
  89         }
  90 }
  91
  92 void machine_restart(char * __unused)
  93 {
  94         local_irq_disable();
  95         __asm__("jmp @@0");
  96 }
  97
  98 void machine_halt(void)
  99 {
 100         local_irq_disable();
 101         __asm__("sleep");
 102         for (;;);
 103 }
 104
 105 void machine_power_off(void)
 106 {
 107         local_irq_disable();
 108         __asm__("sleep");
 109         for (;;);
 110 }
 111
 112 void show_regs(struct pt_regs * regs)
 113 {
 114         printk("\nPC: %08lx  Status: %02x",
 115                regs->pc, regs->ccr);
 116         printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
 117                regs->orig_er0, regs->er0, regs->er1);
 118         printk("\nER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx",
 119                regs->er2, regs->er3, regs->er4, regs->er5);
 120         printk("\nER6' %08lx ",regs->er6);
 121         if (user_mode(regs))
 122                 printk("USP: %08lx\n", rdusp());
 123         else
 124                 printk("\n");
 125 }
 126
 127 /*
 128  * Create a kernel thread
 129  */
 130 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 131 {
 132         long retval;
 133         long clone_arg;
 134         mm_segment_t fs;
 135
 136         fs = get_fs();
 137         set_fs (KERNEL_DS);
 138         clone_arg = flags | CLONE_VM;
 139         __asm__("mov.l sp,er3\n\t"
 140                 "sub.l er2,er2\n\t"
 141                 "mov.l %2,er1\n\t"
 142                 "mov.l %1,er0\n\t"
 143                 "trapa #0\n\t"
 144                 "cmp.l sp,er3\n\t"
 145                 "beq 1f\n\t"
 146                 "mov.l %4,er0\n\t"
 147                 "mov.l %3,er1\n\t"
 148                 "jsr @er1\n\t"
 149                 "mov.l %5,er0\n\t"
 150                 "trapa #0\n"
 151                 "1:\n\t"
 152                 "mov.l er0,%0"
 153                 :"=r"(retval)
 154                 :"i"(__NR_clone),"g"(clone_arg),"g"(fn),"g"(arg),"i"(__NR_exit)
 155                 :"er0","er1","er2","er3");
 156         set_fs (fs);
 157         return retval;
 158 }
 159
 160 void flush_thread(void)
 161 {
 162 }
 163
 164 /*
 165  * "h8300_fork()".. By the time we get here, the
 166  * non-volatile registers have also been saved on the
 167  * stack. We do some ugly pointer stuff here.. (see
 168  * also copy_thread)
 169  */
 170
 171 asmlinkage int h8300_fork(struct pt_regs *regs)
 172 {
 173         return -EINVAL;
 174 }
 175
 176 asmlinkage int h8300_vfork(struct pt_regs *regs)
 177 {
 178         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 179 }
 180
 181 asmlinkage int h8300_clone(struct pt_regs *regs)
 182 {
 183         unsigned long clone_flags;
 184         unsigned long newsp;
 185
 186         /* syscall2 puts clone_flags in er1 and usp in er2 */
 187         clone_flags = regs->er1;
 188         newsp = regs->er2;
 189         if (!newsp)
 190                 newsp  = rdusp();
 191         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 192
 193 }
 194
 195 int copy_thread(int nr, unsigned long clone_flags,
 196                 unsigned long usp, unsigned long topstk,
 197                  struct task_struct * p, struct pt_regs * regs)
 198 {
 199         struct pt_regs * childregs;
 200
 201         childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
 202
 203         *childregs = *regs;
 204         childregs->retpc = (unsigned long) ret_from_fork;
 205         childregs->er0 = 0;
 206
 207         p->thread.usp = usp;
 208         p->thread.ksp = (unsigned long)childregs;
 209
 210         return 0;
 211 }
 212
 213 /*
 214  * sys_execve() executes a new program.
 215  */
 216 asmlinkage int sys_execve(char *name, char **argv, char **envp,int dummy,...)
 217 {
 218         int error;
 219         char * filename;
 220         struct pt_regs *regs = (struct pt_regs *) ((unsigned char *)&dummy-4);
 221
 222         lock_kernel();
 223         filename = getname(name);
 224         error = PTR_ERR(filename);
 225         if (IS_ERR(filename))
 226                 goto out;
 227         error = do_execve(filename, argv, envp, regs);
 228         putname(filename);
 229 out:
 230         unlock_kernel();
 231         return error;
 232 }
 233
 234 unsigned long thread_saved_pc(struct task_struct *tsk)
 235 {
 236         return ((struct pt_regs *)tsk->thread.esp0)->pc;
 237 }
 238
 239 unsigned long get_wchan(struct task_struct *p)
 240 {
 241         unsigned long fp, pc;
 242         unsigned long stack_page;
 243         int count = 0;
 244         if (!p || p == current || p->state == TASK_RUNNING)
 245                 return 0;
 246
 247         stack_page = (unsigned long)p;
 248         fp = ((struct pt_regs *)p->thread.ksp)->er6;
 249         do {
 250                 if (fp < stack_page+sizeof(struct thread_info) ||
 251                     fp >= 8184+stack_page)
 252                         return 0;
 253                 pc = ((unsigned long *)fp)[1];
 254                 if (!in_sched_functions(pc))
 255                         return pc;
 256                 fp = *(unsigned long *) fp;
 257         } while (count++ < 16);
 258         return 0;
 259 }