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/config.h>
  26 #include <linux/errno.h>
  27 #include <linux/module.h>
  28 #include <linux/sched.h>
  29 #include <linux/kernel.h>
  30 #include <linux/mm.h>
  31 #include <linux/smp.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/stddef.h>
  34 #include <linux/unistd.h>
  35 #include <linux/ptrace.h>
  36 #include <linux/slab.h>
  37 #include <linux/user.h>
  38 #include <linux/a.out.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/reboot.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 asmlinkage void ret_from_fork(void);
  49
  50 /*
  51  * The idle loop on an H8/300..
  52  */
  53 #if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM)
  54 void default_idle(void)
  55 {
  56         local_irq_disable();
  57         if (!need_resched()) {
  58                 local_irq_enable();
  59                 /* XXX: race here! What if need_resched() gets set now? */
  60                 __asm__("sleep");
  61         } else
  62                 local_irq_enable();
  63 }
  64 #else
  65 void default_idle(void)
  66 {
  67         cpu_relax();
  68 }
  69 #endif
  70 void (*idle)(void) = default_idle;
  71
  72 /*
  73  * The idle thread. There's no useful work to be
  74  * done, so just try to conserve power and have a
  75  * low exit latency (ie sit in a loop waiting for
  76  * somebody to say that they'd like to reschedule)
  77  */
  78 void cpu_idle(void)
  79 {
  80         while (1) {
  81                 while (!need_resched())
  82                         idle();
  83                 preempt_enable_no_resched();
  84                 schedule();
  85                 preempt_disable();
  86         }
  87 }
  88
  89 void machine_restart(char * __unused)
  90 {
  91         local_irq_disable();
  92         __asm__("jmp @@0");
  93 }
  94
  95 void machine_halt(void)
  96 {
  97         local_irq_disable();
  98         __asm__("sleep");
  99         for (;;);
 100 }
 101
 102 void machine_power_off(void)
 103 {
 104         local_irq_disable();
 105         __asm__("sleep");
 106         for (;;);
 107 }
 108
 109 void show_regs(struct pt_regs * regs)
 110 {
 111         printk("\nPC: %08lx  Status: %02x",
 112                regs->pc, regs->ccr);
 113         printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
 114                regs->orig_er0, regs->er0, regs->er1);
 115         printk("\nER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx",
 116                regs->er2, regs->er3, regs->er4, regs->er5);
 117         printk("\nER6' %08lx ",regs->er6);
 118         if (user_mode(regs))
 119                 printk("USP: %08lx\n", rdusp());
 120         else
 121                 printk("\n");
 122 }
 123
 124 /*
 125  * Create a kernel thread
 126  */
 127 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 128 {
 129         long retval;
 130         long clone_arg;
 131         mm_segment_t fs;
 132
 133         fs = get_fs();
 134         set_fs (KERNEL_DS);
 135         clone_arg = flags | CLONE_VM;
 136         __asm__("mov.l sp,er3\n\t"
 137                 "sub.l er2,er2\n\t"
 138                 "mov.l %2,er1\n\t"
 139                 "mov.l %1,er0\n\t"
 140                 "trapa #0\n\t"
 141                 "cmp.l sp,er3\n\t"
 142                 "beq 1f\n\t"
 143                 "mov.l %4,er0\n\t"
 144                 "mov.l %3,er1\n\t"
 145                 "jsr @er1\n\t"
 146                 "mov.l %5,er0\n\t"
 147                 "trapa #0\n"
 148                 "1:\n\t"
 149                 "mov.l er0,%0"
 150                 :"=r"(retval)
 151                 :"i"(__NR_clone),"g"(clone_arg),"g"(fn),"g"(arg),"i"(__NR_exit)
 152                 :"er0","er1","er2","er3");
 153         set_fs (fs);
 154         return retval;
 155 }
 156
 157 void flush_thread(void)
 158 {
 159 }
 160
 161 /*
 162  * "h8300_fork()".. By the time we get here, the
 163  * non-volatile registers have also been saved on the
 164  * stack. We do some ugly pointer stuff here.. (see
 165  * also copy_thread)
 166  */
 167
 168 asmlinkage int h8300_fork(struct pt_regs *regs)
 169 {
 170         return -EINVAL;
 171 }
 172
 173 asmlinkage int h8300_vfork(struct pt_regs *regs)
 174 {
 175         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 176 }
 177
 178 asmlinkage int h8300_clone(struct pt_regs *regs)
 179 {
 180         unsigned long clone_flags;
 181         unsigned long newsp;
 182
 183         /* syscall2 puts clone_flags in er1 and usp in er2 */
 184         clone_flags = regs->er1;
 185         newsp = regs->er2;
 186         if (!newsp)
 187                 newsp  = rdusp();
 188         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 189
 190 }
 191
 192 int copy_thread(int nr, unsigned long clone_flags,
 193                 unsigned long usp, unsigned long topstk,
 194                  struct task_struct * p, struct pt_regs * regs)
 195 {
 196         struct pt_regs * childregs;
 197
 198         childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
 199
 200         *childregs = *regs;
 201         childregs->retpc = (unsigned long) ret_from_fork;
 202         childregs->er0 = 0;
 203
 204         p->thread.usp = usp;
 205         p->thread.ksp = (unsigned long)childregs;
 206
 207         return 0;
 208 }
 209
 210 /*
 211  * fill in the user structure for a core dump..
 212  */
 213 void dump_thread(struct pt_regs * regs, struct user * dump)
 214 {
 215 /* changed the size calculations - should hopefully work better. lbt */
 216         dump->magic = CMAGIC;
 217         dump->start_code = 0;
 218         dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
 219         dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
 220         dump->u_dsize = ((unsigned long) (current->mm->brk +
 221                                           (PAGE_SIZE-1))) >> PAGE_SHIFT;
 222         dump->u_dsize -= dump->u_tsize;
 223         dump->u_ssize = 0;
 224
 225         dump->u_ar0 = (struct user_regs_struct *)(((int)(&dump->regs)) -((int)(dump)));
 226         dump->regs.er0 = regs->er0;
 227         dump->regs.er1 = regs->er1;
 228         dump->regs.er2 = regs->er2;
 229         dump->regs.er3 = regs->er3;
 230         dump->regs.er4 = regs->er4;
 231         dump->regs.er5 = regs->er5;
 232         dump->regs.er6 = regs->er6;
 233         dump->regs.orig_er0 = regs->orig_er0;
 234         dump->regs.ccr = regs->ccr;
 235         dump->regs.pc  = regs->pc;
 236 }
 237
 238 /*
 239  * sys_execve() executes a new program.
 240  */
 241 asmlinkage int sys_execve(char *name, char **argv, char **envp,int dummy,...)
 242 {
 243         int error;
 244         char * filename;
 245         struct pt_regs *regs = (struct pt_regs *) ((unsigned char *)&dummy-4);
 246
 247         lock_kernel();
 248         filename = getname(name);
 249         error = PTR_ERR(filename);
 250         if (IS_ERR(filename))
 251                 goto out;
 252         error = do_execve(filename, argv, envp, regs);
 253         putname(filename);
 254 out:
 255         unlock_kernel();
 256         return error;
 257 }
 258
 259 unsigned long thread_saved_pc(struct task_struct *tsk)
 260 {
 261         return ((struct pt_regs *)tsk->thread.esp0)->pc;
 262 }
 263
 264 unsigned long get_wchan(struct task_struct *p)
 265 {
 266         unsigned long fp, pc;
 267         unsigned long stack_page;
 268         int count = 0;
 269         if (!p || p == current || p->state == TASK_RUNNING)
 270                 return 0;
 271
 272         stack_page = (unsigned long)p;
 273         fp = ((struct pt_regs *)p->thread.ksp)->er6;
 274         do {
 275                 if (fp < stack_page+sizeof(struct thread_info) ||
 276                     fp >= 8184+stack_page)
 277                         return 0;
 278                 pc = ((unsigned long *)fp)[1];
 279                 if (!in_sched_functions(pc))
 280                         return pc;
 281                 fp = *(unsigned long *) fp;
 282         } while (count++ < 16);
 283         return 0;
 284 }