arch/m68k/kernel/process_no.c

   1 /*
   2  *  linux/arch/m68knommu/kernel/process.c
   3  *
   4  *  Copyright (C) 1995  Hamish Macdonald
   5  *
   6  *  68060 fixes by Jesper Skov
   7  *
   8  *  uClinux changes
   9  *  Copyright (C) 2000-2002, David McCullough <davidm@snapgear.com>
  10  */
  11
  12 /*
  13  * This file handles the architecture-dependent parts of process handling..
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/errno.h>
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/mm.h>
  21 #include <linux/smp.h>
  22 #include <linux/stddef.h>
  23 #include <linux/unistd.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/user.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/reboot.h>
  28 #include <linux/fs.h>
  29 #include <linux/slab.h>
  30
  31 #include <asm/uaccess.h>
  32 #include <asm/system.h>
  33 #include <asm/traps.h>
  34 #include <asm/machdep.h>
  35 #include <asm/setup.h>
  36 #include <asm/pgtable.h>
  37
  38 asmlinkage void ret_from_fork(void);
  39
  40 /*
  41  * The following aren't currently used.
  42  */
  43 void (*pm_idle)(void);
  44 EXPORT_SYMBOL(pm_idle);
  45
  46 void (*pm_power_off)(void);
  47 EXPORT_SYMBOL(pm_power_off);
  48
  49 /*
  50  * The idle loop on an m68knommu..
  51  */
  52 static void default_idle(void)
  53 {
  54         local_irq_disable();
  55         while (!need_resched()) {
  56                 /* This stop will re-enable interrupts */
  57                 __asm__("stop #0x2000" : : : "cc");
  58                 local_irq_disable();
  59         }
  60         local_irq_enable();
  61 }
  62
  63 void (*idle)(void) = default_idle;
  64
  65 /*
  66  * The idle thread. There's no useful work to be
  67  * done, so just try to conserve power and have a
  68  * low exit latency (ie sit in a loop waiting for
  69  * somebody to say that they'd like to reschedule)
  70  */
  71 void cpu_idle(void)
  72 {
  73         /* endless idle loop with no priority at all */
  74         while (1) {
  75                 idle();
  76                 preempt_enable_no_resched();
  77                 schedule();
  78                 preempt_disable();
  79         }
  80 }
  81
  82 void machine_restart(char * __unused)
  83 {
  84         if (mach_reset)
  85                 mach_reset();
  86         for (;;);
  87 }
  88
  89 void machine_halt(void)
  90 {
  91         if (mach_halt)
  92                 mach_halt();
  93         for (;;);
  94 }
  95
  96 void machine_power_off(void)
  97 {
  98         if (mach_power_off)
  99                 mach_power_off();
 100         for (;;);
 101 }
 102
 103 void show_regs(struct pt_regs * regs)
 104 {
 105         printk(KERN_NOTICE "\n");
 106         printk(KERN_NOTICE "Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
 107                regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
 108         printk(KERN_NOTICE "ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
 109                regs->orig_d0, regs->d0, regs->a2, regs->a1);
 110         printk(KERN_NOTICE "A0: %08lx  D5: %08lx  D4: %08lx\n",
 111                regs->a0, regs->d5, regs->d4);
 112         printk(KERN_NOTICE "D3: %08lx  D2: %08lx  D1: %08lx\n",
 113                regs->d3, regs->d2, regs->d1);
 114         if (!(regs->sr & PS_S))
 115                 printk(KERN_NOTICE "USP: %08lx\n", rdusp());
 116 }
 117
 118 /*
 119  * Create a kernel thread
 120  */
 121 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 122 {
 123         int retval;
 124         long clone_arg = flags | CLONE_VM;
 125         mm_segment_t fs;
 126
 127         fs = get_fs();
 128         set_fs(KERNEL_DS);
 129
 130         __asm__ __volatile__ (
 131                         "movel  %%sp, %%d2\n\t"
 132                         "movel  %5, %%d1\n\t"
 133                         "movel  %1, %%d0\n\t"
 134                         "trap   #0\n\t"
 135                         "cmpl   %%sp, %%d2\n\t"
 136                         "jeq    1f\n\t"
 137                         "movel  %3, %%sp@-\n\t"
 138                         "jsr    %4@\n\t"
 139                         "movel  %2, %%d0\n\t"
 140                         "trap   #0\n"
 141                         "1:\n\t"
 142                         "movel  %%d0, %0\n"
 143                 : "=d" (retval)
 144                 : "i" (__NR_clone),
 145                   "i" (__NR_exit),
 146                   "a" (arg),
 147                   "a" (fn),
 148                   "a" (clone_arg)
 149                 : "cc", "%d0", "%d1", "%d2");
 150
 151         set_fs(fs);
 152         return retval;
 153 }
 154 EXPORT_SYMBOL(kernel_thread);
 155
 156 void flush_thread(void)
 157 {
 158 #ifdef CONFIG_FPU
 159         unsigned long zero = 0;
 160 #endif
 161
 162         current->thread.fs = __USER_DS;
 163 #ifdef CONFIG_FPU
 164         if (!FPU_IS_EMU)
 165                 asm volatile (".chip 68k/68881\n\t"
 166                               "frestore %0@\n\t"
 167                               ".chip 68k" : : "a" (&zero));
 168 #endif
 169 }
 170
 171 /*
 172  * "m68k_fork()".. By the time we get here, the
 173  * non-volatile registers have also been saved on the
 174  * stack. We do some ugly pointer stuff here.. (see
 175  * also copy_thread)
 176  */
 177
 178 asmlinkage int m68k_fork(struct pt_regs *regs)
 179 {
 180         /* fork almost works, enough to trick you into looking elsewhere :-( */
 181         return(-EINVAL);
 182 }
 183
 184 asmlinkage int m68k_vfork(struct pt_regs *regs)
 185 {
 186         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 187 }
 188
 189 asmlinkage int m68k_clone(struct pt_regs *regs)
 190 {
 191         unsigned long clone_flags;
 192         unsigned long newsp;
 193
 194         /* syscall2 puts clone_flags in d1 and usp in d2 */
 195         clone_flags = regs->d1;
 196         newsp = regs->d2;
 197         if (!newsp)
 198                 newsp = rdusp();
 199         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 200 }
 201
 202 int copy_thread(unsigned long clone_flags,
 203                 unsigned long usp, unsigned long topstk,
 204                 struct task_struct * p, struct pt_regs * regs)
 205 {
 206         struct pt_regs * childregs;
 207         struct switch_stack * childstack, *stack;
 208         unsigned long *retp;
 209
 210         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
 211
 212         *childregs = *regs;
 213         childregs->d0 = 0;
 214
 215         retp = ((unsigned long *) regs);
 216         stack = ((struct switch_stack *) retp) - 1;
 217
 218         childstack = ((struct switch_stack *) childregs) - 1;
 219         *childstack = *stack;
 220         childstack->retpc = (unsigned long)ret_from_fork;
 221
 222         p->thread.usp = usp;
 223         p->thread.ksp = (unsigned long)childstack;
 224
 225         if (clone_flags & CLONE_SETTLS)
 226                 task_thread_info(p)->tp_value = regs->d5;
 227
 228         /*
 229          * Must save the current SFC/DFC value, NOT the value when
 230          * the parent was last descheduled - RGH  10-08-96
 231          */
 232         p->thread.fs = get_fs().seg;
 233
 234 #ifdef CONFIG_FPU
 235         if (!FPU_IS_EMU) {
 236                 /* Copy the current fpu state */
 237                 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
 238
 239                 if (p->thread.fpstate[0])
 240                   asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
 241                                 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
 242                                 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
 243                                 : "memory");
 244                 /* Restore the state in case the fpu was busy */
 245                 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
 246         }
 247 #endif
 248
 249         return 0;
 250 }
 251
 252 /* Fill in the fpu structure for a core dump.  */
 253
 254 int dump_fpu(struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 255 {
 256 #ifdef CONFIG_FPU
 257         char fpustate[216];
 258
 259         if (FPU_IS_EMU) {
 260                 int i;
 261
 262                 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
 263                 memcpy(fpu->fpregs, current->thread.fp, 96);
 264                 /* Convert internal fpu reg representation
 265                  * into long double format
 266                  */
 267                 for (i = 0; i < 24; i += 3)
 268                         fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
 269                                          ((fpu->fpregs[i] & 0x0000ffff) << 16);
 270                 return 1;
 271         }
 272
 273         /* First dump the fpu context to avoid protocol violation.  */
 274         asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
 275         if (!fpustate[0])
 276                 return 0;
 277
 278         asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
 279                 :: "m" (fpu->fpcntl[0])
 280                 : "memory");
 281         asm volatile ("fmovemx %/fp0-%/fp7,%0"
 282                 :: "m" (fpu->fpregs[0])
 283                 : "memory");
 284 #endif
 285         return 1;
 286 }
 287 EXPORT_SYMBOL(dump_fpu);
 288
 289 /*
 290  *      Generic dumping code. Used for panic and debug.
 291  */
 292 void dump(struct pt_regs *fp)
 293 {
 294         unsigned long   *sp;
 295         unsigned char   *tp;
 296         int             i;
 297
 298         printk(KERN_EMERG "\nCURRENT PROCESS:\n\n");
 299         printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);
 300
 301         if (current->mm) {
 302                 printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 303                         (int) current->mm->start_code,
 304                         (int) current->mm->end_code,
 305                         (int) current->mm->start_data,
 306                         (int) current->mm->end_data,
 307                         (int) current->mm->end_data,
 308                         (int) current->mm->brk);
 309                 printk(KERN_EMERG "USER-STACK=%08x KERNEL-STACK=%08x\n\n",
 310                         (int) current->mm->start_stack,
 311                         (int)(((unsigned long) current) + THREAD_SIZE));
 312         }
 313
 314         printk(KERN_EMERG "PC: %08lx\n", fp->pc);
 315         printk(KERN_EMERG "SR: %08lx    SP: %08lx\n", (long) fp->sr, (long) fp);
 316         printk(KERN_EMERG "d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 317                 fp->d0, fp->d1, fp->d2, fp->d3);
 318         printk(KERN_EMERG "d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 319                 fp->d4, fp->d5, fp->a0, fp->a1);
 320         printk(KERN_EMERG "\nUSP: %08x   TRAPFRAME: %p\n",
 321                 (unsigned int) rdusp(), fp);
 322
 323         printk(KERN_EMERG "\nCODE:");
 324         tp = ((unsigned char *) fp->pc) - 0x20;
 325         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 326                 if ((i % 0x10) == 0)
 327                         printk(KERN_EMERG "%p: ", tp + i);
 328                 printk("%08x ", (int) *sp++);
 329         }
 330         printk(KERN_EMERG "\n");
 331
 332         printk(KERN_EMERG "KERNEL STACK:");
 333         tp = ((unsigned char *) fp) - 0x40;
 334         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 335                 if ((i % 0x10) == 0)
 336                         printk(KERN_EMERG "%p: ", tp + i);
 337                 printk("%08x ", (int) *sp++);
 338         }
 339         printk(KERN_EMERG "\n");
 340
 341         printk(KERN_EMERG "USER STACK:");
 342         tp = (unsigned char *) (rdusp() - 0x10);
 343         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 344                 if ((i % 0x10) == 0)
 345                         printk(KERN_EMERG "%p: ", tp + i);
 346                 printk("%08x ", (int) *sp++);
 347         }
 348         printk(KERN_EMERG "\n");
 349 }
 350
 351 /*
 352  * sys_execve() executes a new program.
 353  */
 354 asmlinkage int sys_execve(const char *name,
 355                           const char *const *argv,
 356                           const char *const *envp)
 357 {
 358         int error;
 359         char * filename;
 360         struct pt_regs *regs = (struct pt_regs *) &name;
 361
 362         filename = getname(name);
 363         error = PTR_ERR(filename);
 364         if (IS_ERR(filename))
 365                 return error;
 366         error = do_execve(filename, argv, envp, regs);
 367         putname(filename);
 368         return error;
 369 }
 370
 371 unsigned long get_wchan(struct task_struct *p)
 372 {
 373         unsigned long fp, pc;
 374         unsigned long stack_page;
 375         int count = 0;
 376         if (!p || p == current || p->state == TASK_RUNNING)
 377                 return 0;
 378
 379         stack_page = (unsigned long)p;
 380         fp = ((struct switch_stack *)p->thread.ksp)->a6;
 381         do {
 382                 if (fp < stack_page+sizeof(struct thread_info) ||
 383                     fp >= THREAD_SIZE-8+stack_page)
 384                         return 0;
 385                 pc = ((unsigned long *)fp)[1];
 386                 if (!in_sched_functions(pc))
 387                         return pc;
 388                 fp = *(unsigned long *) fp;
 389         } while (count++ < 16);
 390         return 0;
 391 }
 392
 393 /*
 394  * Return saved PC of a blocked thread.
 395  */
 396 unsigned long thread_saved_pc(struct task_struct *tsk)
 397 {
 398         struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
 399
 400         /* Check whether the thread is blocked in resume() */
 401         if (in_sched_functions(sw->retpc))
 402                 return ((unsigned long *)sw->a6)[1];
 403         else
 404                 return sw->retpc;
 405 }
 406