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         while(1) {
  57                 if (need_resched()) {
  58                         sti();
  59                         __asm__("sleep");
  60                         cli();
  61                 }
  62                 schedule();
  63         }
  64 }
  65 #else
  66 void default_idle(void)
  67 {
  68         while(1) {
  69                 if (need_resched())
  70                         schedule();
  71         }
  72 }
  73 #endif
  74 void (*idle)(void) = default_idle;
  75
  76 /*
  77  * The idle thread. There's no useful work to be
  78  * done, so just try to conserve power and have a
  79  * low exit latency (ie sit in a loop waiting for
  80  * somebody to say that they'd like to reschedule)
  81  */
  82 void cpu_idle(void)
  83 {
  84         idle();
  85 }
  86
  87 void machine_restart(char * __unused)
  88 {
  89         local_irq_disable();
  90         __asm__("jmp @@0");
  91 }
  92
  93 EXPORT_SYMBOL(machine_restart);
  94
  95 void machine_halt(void)
  96 {
  97         local_irq_disable();
  98         __asm__("sleep");
  99         for (;;);
 100 }
 101
 102 EXPORT_SYMBOL(machine_halt);
 103
 104 void machine_power_off(void)
 105 {
 106         local_irq_disable();
 107         __asm__("sleep");
 108         for (;;);
 109 }
 110
 111 EXPORT_SYMBOL(machine_power_off);
 112
 113 void show_regs(struct pt_regs * regs)
 114 {
 115         printk("\n");
 116         printk("PC: %08lx  Status: %02x\n",
 117                regs->pc, regs->ccr);
 118         printk("ORIG_ER0: %08lx ER0: %08lx ER1: %08lx\n",
 119                regs->orig_er0, regs->er0, regs->er1);
 120         printk("ER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx\n",
 121                regs->er2, regs->er3, regs->er4, regs->er5);
 122         printk("ER6' %08lx ",regs->er6);
 123         if (user_mode(regs))
 124                 printk("USP: %08lx\n", rdusp());
 125         else
 126                 printk("\n");
 127 }
 128
 129 /*
 130  * Create a kernel thread
 131  */
 132 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 133 {
 134         long retval;
 135         long clone_arg;
 136         mm_segment_t fs;
 137
 138         fs = get_fs();
 139         set_fs (KERNEL_DS);
 140         clone_arg = flags | CLONE_VM;
 141         __asm__("mov.l sp,er3\n\t"
 142                 "sub.l er2,er2\n\t"
 143                 "mov.l %2,er1\n\t"
 144                 "mov.l %1,er0\n\t"
 145                 "trapa #0\n\t"
 146                 "cmp.l sp,er3\n\t"
 147                 "beq 1f\n\t"
 148                 "mov.l %4,er0\n\t"
 149                 "mov.l %3,er1\n\t"
 150                 "jsr @er1\n\t"
 151                 "mov.l %5,er0\n\t"
 152                 "trapa #0\n"
 153                 "1:\n\t"
 154                 "mov.l er0,%0"
 155                 :"=r"(retval)
 156                 :"i"(__NR_clone),"g"(clone_arg),"g"(fn),"g"(arg),"i"(__NR_exit)
 157                 :"er0","er1","er2","er3");
 158         set_fs (fs);
 159         return retval;
 160 }
 161
 162 void flush_thread(void)
 163 {
 164 }
 165
 166 /*
 167  * "h8300_fork()".. By the time we get here, the
 168  * non-volatile registers have also been saved on the
 169  * stack. We do some ugly pointer stuff here.. (see
 170  * also copy_thread)
 171  */
 172
 173 asmlinkage int h8300_fork(struct pt_regs *regs)
 174 {
 175         return -EINVAL;
 176 }
 177
 178 asmlinkage int h8300_vfork(struct pt_regs *regs)
 179 {
 180         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 181 }
 182
 183 asmlinkage int h8300_clone(struct pt_regs *regs)
 184 {
 185         unsigned long clone_flags;
 186         unsigned long newsp;
 187
 188         /* syscall2 puts clone_flags in er1 and usp in er2 */
 189         clone_flags = regs->er1;
 190         newsp = regs->er2;
 191         if (!newsp)
 192                 newsp  = rdusp();
 193         return do_fork(clone_flags & ~CLONE_IDLETASK, newsp, regs, 0, NULL, NULL);
 194
 195 }
 196
 197 int copy_thread(int nr, unsigned long clone_flags,
 198                 unsigned long usp, unsigned long topstk,
 199                  struct task_struct * p, struct pt_regs * regs)
 200 {
 201         struct pt_regs * childregs;
 202
 203         childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
 204
 205         *childregs = *regs;
 206         childregs->retpc = (unsigned long) ret_from_fork;
 207         childregs->er0 = 0;
 208
 209         p->thread.usp = usp;
 210         p->thread.ksp = (unsigned long)childregs;
 211
 212         return 0;
 213 }
 214
 215 /*
 216  * fill in the user structure for a core dump..
 217  */
 218 void dump_thread(struct pt_regs * regs, struct user * dump)
 219 {
 220 /* changed the size calculations - should hopefully work better. lbt */
 221         dump->magic = CMAGIC;
 222         dump->start_code = 0;
 223         dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
 224         dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
 225         dump->u_dsize = ((unsigned long) (current->mm->brk +
 226                                           (PAGE_SIZE-1))) >> PAGE_SHIFT;
 227         dump->u_dsize -= dump->u_tsize;
 228         dump->u_ssize = 0;
 229
 230         dump->u_ar0 = (struct user_regs_struct *)(((int)(&dump->regs)) -((int)(dump)));
 231         dump->regs.er0 = regs->er0;
 232         dump->regs.er1 = regs->er1;
 233         dump->regs.er2 = regs->er2;
 234         dump->regs.er3 = regs->er3;
 235         dump->regs.er4 = regs->er4;
 236         dump->regs.er5 = regs->er5;
 237         dump->regs.er6 = regs->er6;
 238         dump->regs.orig_er0 = regs->orig_er0;
 239         dump->regs.ccr = regs->ccr;
 240         dump->regs.pc  = regs->pc;
 241 }
 242
 243 /*
 244  * sys_execve() executes a new program.
 245  */
 246 asmlinkage int sys_execve(char *name, char **argv, char **envp,int dummy,...)
 247 {
 248         int error;
 249         char * filename;
 250         struct pt_regs *regs = (struct pt_regs *) ((unsigned char *)&dummy-4);
 251
 252         lock_kernel();
 253         filename = getname(name);
 254         error = PTR_ERR(filename);
 255         if (IS_ERR(filename))
 256                 goto out;
 257         error = do_execve(filename, argv, envp, regs);
 258         putname(filename);
 259 out:
 260         unlock_kernel();
 261         return error;
 262 }
 263
 264 /*
 265  * These bracket the sleeping functions..
 266  */
 267 #define first_sched     ((unsigned long) scheduling_functions_start_here)
 268 #define last_sched      ((unsigned long) scheduling_functions_end_here)
 269
 270 unsigned long thread_saved_pc(struct task_struct *tsk)
 271 {
 272         return ((struct pt_regs *)tsk->thread.esp0)->pc;
 273 }
 274
 275 unsigned long get_wchan(struct task_struct *p)
 276 {
 277         unsigned long fp, pc;
 278         unsigned long stack_page;
 279         int count = 0;
 280         if (!p || p == current || p->state == TASK_RUNNING)
 281                 return 0;
 282
 283         stack_page = (unsigned long)p;
 284         fp = ((struct pt_regs *)p->thread.ksp)->er6;
 285         do {
 286                 if (fp < stack_page+sizeof(struct thread_info) ||
 287                     fp >= 8184+stack_page)
 288                         return 0;
 289                 pc = ((unsigned long *)fp)[1];
 290                 if (pc < first_sched || pc >= last_sched)
 291                         return pc;
 292                 fp = *(unsigned long *) fp;
 293         } while (count++ < 16);
 294         return 0;
 295 }