arch/m68knommu/kernel/process.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/config.h>
  17 #include <linux/module.h>
  18 #include <linux/errno.h>
  19 #include <linux/sched.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mm.h>
  22 #include <linux/smp.h>
  23 #include <linux/smp_lock.h>
  24 #include <linux/stddef.h>
  25 #include <linux/unistd.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/slab.h>
  28 #include <linux/user.h>
  29 #include <linux/a.out.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/reboot.h>
  32
  33 #include <asm/uaccess.h>
  34 #include <asm/system.h>
  35 #include <asm/traps.h>
  36 #include <asm/machdep.h>
  37 #include <asm/setup.h>
  38 #include <asm/pgtable.h>
  39
  40 asmlinkage void ret_from_fork(void);
  41
  42
  43 /*
  44  * The idle loop on an m68knommu..
  45  */
  46 void default_idle(void)
  47 {
  48         local_irq_disable();
  49         while (!need_resched()) {
  50                 /* This stop will re-enable interrupts */
  51                 __asm__("stop #0x2000" : : : "cc");
  52                 local_irq_disable();
  53         }
  54         local_irq_enable();
  55 }
  56
  57 void (*idle)(void) = default_idle;
  58
  59 /*
  60  * The idle thread. There's no useful work to be
  61  * done, so just try to conserve power and have a
  62  * low exit latency (ie sit in a loop waiting for
  63  * somebody to say that they'd like to reschedule)
  64  */
  65 void cpu_idle(void)
  66 {
  67         /* endless idle loop with no priority at all */
  68         while (1) {
  69                 idle();
  70                 preempt_enable_no_resched();
  71                 schedule();
  72                 preempt_disable();
  73         }
  74 }
  75
  76 void machine_restart(char * __unused)
  77 {
  78         if (mach_reset)
  79                 mach_reset();
  80         for (;;);
  81 }
  82
  83 EXPORT_SYMBOL(machine_restart);
  84
  85 void machine_halt(void)
  86 {
  87         if (mach_halt)
  88                 mach_halt();
  89         for (;;);
  90 }
  91
  92 EXPORT_SYMBOL(machine_halt);
  93
  94 void machine_power_off(void)
  95 {
  96         if (mach_power_off)
  97                 mach_power_off();
  98         for (;;);
  99 }
 100
 101 EXPORT_SYMBOL(machine_power_off);
 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
 155 void flush_thread(void)
 156 {
 157 #ifdef CONFIG_FPU
 158         unsigned long zero = 0;
 159 #endif
 160         set_fs(USER_DS);
 161         current->thread.fs = __USER_DS;
 162 #ifdef CONFIG_FPU
 163         if (!FPU_IS_EMU)
 164                 asm volatile (".chip 68k/68881\n\t"
 165                               "frestore %0@\n\t"
 166                               ".chip 68k" : : "a" (&zero));
 167 #endif
 168 }
 169
 170 /*
 171  * "m68k_fork()".. By the time we get here, the
 172  * non-volatile registers have also been saved on the
 173  * stack. We do some ugly pointer stuff here.. (see
 174  * also copy_thread)
 175  */
 176
 177 asmlinkage int m68k_fork(struct pt_regs *regs)
 178 {
 179         /* fork almost works, enough to trick you into looking elsewhere :-( */
 180         return(-EINVAL);
 181 }
 182
 183 asmlinkage int m68k_vfork(struct pt_regs *regs)
 184 {
 185         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 186 }
 187
 188 asmlinkage int m68k_clone(struct pt_regs *regs)
 189 {
 190         unsigned long clone_flags;
 191         unsigned long newsp;
 192
 193         /* syscall2 puts clone_flags in d1 and usp in d2 */
 194         clone_flags = regs->d1;
 195         newsp = regs->d2;
 196         if (!newsp)
 197                 newsp = rdusp();
 198         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 199 }
 200
 201 int copy_thread(int nr, unsigned long clone_flags,
 202                 unsigned long usp, unsigned long topstk,
 203                 struct task_struct * p, struct pt_regs * regs)
 204 {
 205         struct pt_regs * childregs;
 206         struct switch_stack * childstack, *stack;
 207         unsigned long stack_offset, *retp;
 208
 209         stack_offset = THREAD_SIZE - sizeof(struct pt_regs);
 210         childregs = (struct pt_regs *) ((unsigned long) p->thread_info + stack_offset);
 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          * Must save the current SFC/DFC value, NOT the value when
 226          * the parent was last descheduled - RGH  10-08-96
 227          */
 228         p->thread.fs = get_fs().seg;
 229
 230 #ifdef CONFIG_FPU
 231         if (!FPU_IS_EMU) {
 232                 /* Copy the current fpu state */
 233                 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
 234
 235                 if (p->thread.fpstate[0])
 236                   asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
 237                                 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
 238                                 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
 239                                 : "memory");
 240                 /* Restore the state in case the fpu was busy */
 241                 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
 242         }
 243 #endif
 244
 245         return 0;
 246 }
 247
 248 /* Fill in the fpu structure for a core dump.  */
 249
 250 int dump_fpu(struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 251 {
 252 #ifdef CONFIG_FPU
 253         char fpustate[216];
 254
 255         if (FPU_IS_EMU) {
 256                 int i;
 257
 258                 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
 259                 memcpy(fpu->fpregs, current->thread.fp, 96);
 260                 /* Convert internal fpu reg representation
 261                  * into long double format
 262                  */
 263                 for (i = 0; i < 24; i += 3)
 264                         fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
 265                                          ((fpu->fpregs[i] & 0x0000ffff) << 16);
 266                 return 1;
 267         }
 268
 269         /* First dump the fpu context to avoid protocol violation.  */
 270         asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
 271         if (!fpustate[0])
 272                 return 0;
 273
 274         asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
 275                 :: "m" (fpu->fpcntl[0])
 276                 : "memory");
 277         asm volatile ("fmovemx %/fp0-%/fp7,%0"
 278                 :: "m" (fpu->fpregs[0])
 279                 : "memory");
 280 #endif
 281         return 1;
 282 }
 283
 284 /*
 285  * fill in the user structure for a core dump..
 286  */
 287 void dump_thread(struct pt_regs * regs, struct user * dump)
 288 {
 289         struct switch_stack *sw;
 290
 291         /* changed the size calculations - should hopefully work better. lbt */
 292         dump->magic = CMAGIC;
 293         dump->start_code = 0;
 294         dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
 295         dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
 296         dump->u_dsize = ((unsigned long) (current->mm->brk +
 297                                           (PAGE_SIZE-1))) >> PAGE_SHIFT;
 298         dump->u_dsize -= dump->u_tsize;
 299         dump->u_ssize = 0;
 300
 301         if (dump->start_stack < TASK_SIZE)
 302                 dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
 303
 304         dump->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump);
 305         sw = ((struct switch_stack *)regs) - 1;
 306         dump->regs.d1 = regs->d1;
 307         dump->regs.d2 = regs->d2;
 308         dump->regs.d3 = regs->d3;
 309         dump->regs.d4 = regs->d4;
 310         dump->regs.d5 = regs->d5;
 311         dump->regs.d6 = sw->d6;
 312         dump->regs.d7 = sw->d7;
 313         dump->regs.a0 = regs->a0;
 314         dump->regs.a1 = regs->a1;
 315         dump->regs.a2 = regs->a2;
 316         dump->regs.a3 = sw->a3;
 317         dump->regs.a4 = sw->a4;
 318         dump->regs.a5 = sw->a5;
 319         dump->regs.a6 = sw->a6;
 320         dump->regs.d0 = regs->d0;
 321         dump->regs.orig_d0 = regs->orig_d0;
 322         dump->regs.stkadj = regs->stkadj;
 323         dump->regs.sr = regs->sr;
 324         dump->regs.pc = regs->pc;
 325         dump->regs.fmtvec = (regs->format << 12) | regs->vector;
 326         /* dump floating point stuff */
 327         dump->u_fpvalid = dump_fpu (regs, &dump->m68kfp);
 328 }
 329
 330 /*
 331  *      Generic dumping code. Used for panic and debug.
 332  */
 333 void dump(struct pt_regs *fp)
 334 {
 335         unsigned long   *sp;
 336         unsigned char   *tp;
 337         int             i;
 338
 339         printk(KERN_EMERG "\nCURRENT PROCESS:\n\n");
 340         printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);
 341
 342         if (current->mm) {
 343                 printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 344                         (int) current->mm->start_code,
 345                         (int) current->mm->end_code,
 346                         (int) current->mm->start_data,
 347                         (int) current->mm->end_data,
 348                         (int) current->mm->end_data,
 349                         (int) current->mm->brk);
 350                 printk(KERN_EMERG "USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 351                         (int) current->mm->start_stack,
 352                         (int)(((unsigned long) current) + THREAD_SIZE));
 353         }
 354
 355         printk(KERN_EMERG "PC: %08lx\n", fp->pc);
 356         printk(KERN_EMERG "SR: %08lx    SP: %08lx\n", (long) fp->sr, (long) fp);
 357         printk(KERN_EMERG "d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 358                 fp->d0, fp->d1, fp->d2, fp->d3);
 359         printk(KERN_EMERG "d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 360                 fp->d4, fp->d5, fp->a0, fp->a1);
 361         printk(KERN_EMERG "\nUSP: %08x   TRAPFRAME: %08x\n", (unsigned int) rdusp(),
 362                 (unsigned int) fp);
 363
 364         printk(KERN_EMERG "\nCODE:");
 365         tp = ((unsigned char *) fp->pc) - 0x20;
 366         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 367                 if ((i % 0x10) == 0)
 368                         printk(KERN_EMERG "\n%08x: ", (int) (tp + i));
 369                 printk(KERN_EMERG "%08x ", (int) *sp++);
 370         }
 371         printk(KERN_EMERG "\n");
 372
 373         printk(KERN_EMERG "\nKERNEL STACK:");
 374         tp = ((unsigned char *) fp) - 0x40;
 375         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 376                 if ((i % 0x10) == 0)
 377                         printk(KERN_EMERG "\n%08x: ", (int) (tp + i));
 378                 printk(KERN_EMERG "%08x ", (int) *sp++);
 379         }
 380         printk(KERN_EMERG "\n");
 381         printk(KERN_EMERG "\n");
 382
 383         printk(KERN_EMERG "\nUSER STACK:");
 384         tp = (unsigned char *) (rdusp() - 0x10);
 385         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 386                 if ((i % 0x10) == 0)
 387                         printk(KERN_EMERG "\n%08x: ", (int) (tp + i));
 388                 printk(KERN_EMERG "%08x ", (int) *sp++);
 389         }
 390         printk(KERN_EMERG "\n\n");
 391 }
 392
 393 /*
 394  * sys_execve() executes a new program.
 395  */
 396 asmlinkage int sys_execve(char *name, char **argv, char **envp)
 397 {
 398         int error;
 399         char * filename;
 400         struct pt_regs *regs = (struct pt_regs *) &name;
 401
 402         lock_kernel();
 403         filename = getname(name);
 404         error = PTR_ERR(filename);
 405         if (IS_ERR(filename))
 406                 goto out;
 407         error = do_execve(filename, argv, envp, regs);
 408         putname(filename);
 409 out:
 410         unlock_kernel();
 411         return error;
 412 }
 413
 414 unsigned long get_wchan(struct task_struct *p)
 415 {
 416         unsigned long fp, pc;
 417         unsigned long stack_page;
 418         int count = 0;
 419         if (!p || p == current || p->state == TASK_RUNNING)
 420                 return 0;
 421
 422         stack_page = (unsigned long)p;
 423         fp = ((struct switch_stack *)p->thread.ksp)->a6;
 424         do {
 425                 if (fp < stack_page+sizeof(struct thread_info) ||
 426                     fp >= 8184+stack_page)
 427                         return 0;
 428                 pc = ((unsigned long *)fp)[1];
 429                 if (!in_sched_functions(pc))
 430                         return pc;
 431                 fp = *(unsigned long *) fp;
 432         } while (count++ < 16);
 433         return 0;
 434 }
 435
 436 /*
 437  * Return saved PC of a blocked thread.
 438  */
 439 unsigned long thread_saved_pc(struct task_struct *tsk)
 440 {
 441         struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
 442
 443         /* Check whether the thread is blocked in resume() */
 444         if (in_sched_functions(sw->retpc))
 445                 return ((unsigned long *)sw->a6)[1];
 446         else
 447                 return sw->retpc;
 448 }
 449