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         while(1) {
  49                 if (need_resched())
  50                         __asm__("stop #0x2000" : : : "cc");
  51                 schedule();
  52         }
  53 }
  54
  55 void (*idle)(void) = default_idle;
  56
  57 /*
  58  * The idle thread. There's no useful work to be
  59  * done, so just try to conserve power and have a
  60  * low exit latency (ie sit in a loop waiting for
  61  * somebody to say that they'd like to reschedule)
  62  */
  63 void cpu_idle(void)
  64 {
  65         /* endless idle loop with no priority at all */
  66         idle();
  67 }
  68
  69 void machine_restart(char * __unused)
  70 {
  71         if (mach_reset)
  72                 mach_reset();
  73         for (;;);
  74 }
  75
  76 EXPORT_SYMBOL(machine_restart);
  77
  78 void machine_halt(void)
  79 {
  80         if (mach_halt)
  81                 mach_halt();
  82         for (;;);
  83 }
  84
  85 EXPORT_SYMBOL(machine_halt);
  86
  87 void machine_power_off(void)
  88 {
  89         if (mach_power_off)
  90                 mach_power_off();
  91         for (;;);
  92 }
  93
  94 EXPORT_SYMBOL(machine_power_off);
  95
  96 void show_regs(struct pt_regs * regs)
  97 {
  98         printk(KERN_NOTICE "\n");
  99         printk(KERN_NOTICE "Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
 100                regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
 101         printk(KERN_NOTICE "ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
 102                regs->orig_d0, regs->d0, regs->a2, regs->a1);
 103         printk(KERN_NOTICE "A0: %08lx  D5: %08lx  D4: %08lx\n",
 104                regs->a0, regs->d5, regs->d4);
 105         printk(KERN_NOTICE "D3: %08lx  D2: %08lx  D1: %08lx\n",
 106                regs->d3, regs->d2, regs->d1);
 107         if (!(regs->sr & PS_S))
 108                 printk(KERN_NOTICE "USP: %08lx\n", rdusp());
 109 }
 110
 111 /*
 112  * Create a kernel thread
 113  */
 114 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 115 {
 116         int retval;
 117         long clone_arg = flags | CLONE_VM;
 118         mm_segment_t fs;
 119
 120         fs = get_fs();
 121         set_fs(KERNEL_DS);
 122
 123         __asm__ __volatile__ (
 124                         "movel  %%sp, %%d2\n\t"
 125                         "movel  %5, %%d1\n\t"
 126                         "movel  %1, %%d0\n\t"
 127                         "trap   #0\n\t"
 128                         "cmpl   %%sp, %%d2\n\t"
 129                         "jeq    1f\n\t"
 130                         "movel  %3, %%sp@-\n\t"
 131                         "jsr    %4@\n\t"
 132                         "movel  %2, %%d0\n\t"
 133                         "trap   #0\n"
 134                         "1:\n\t"
 135                         "movel  %%d0, %0\n"
 136                 : "=d" (retval)
 137                 : "i" (__NR_clone),
 138                   "i" (__NR_exit),
 139                   "a" (arg),
 140                   "a" (fn),
 141                   "a" (clone_arg)
 142                 : "cc", "%d0", "%d1", "%d2");
 143
 144         set_fs(fs);
 145         return retval;
 146 }
 147
 148 void flush_thread(void)
 149 {
 150 #ifdef CONFIG_FPU
 151         unsigned long zero = 0;
 152 #endif
 153         set_fs(USER_DS);
 154         current->thread.fs = __USER_DS;
 155 #ifdef CONFIG_FPU
 156         if (!FPU_IS_EMU)
 157                 asm volatile (".chip 68k/68881\n\t"
 158                               "frestore %0@\n\t"
 159                               ".chip 68k" : : "a" (&zero));
 160 #endif
 161 }
 162
 163 /*
 164  * "m68k_fork()".. By the time we get here, the
 165  * non-volatile registers have also been saved on the
 166  * stack. We do some ugly pointer stuff here.. (see
 167  * also copy_thread)
 168  */
 169
 170 asmlinkage int m68k_fork(struct pt_regs *regs)
 171 {
 172         /* fork almost works, enough to trick you into looking elsewhere :-( */
 173         return(-EINVAL);
 174 }
 175
 176 asmlinkage int m68k_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 m68k_clone(struct pt_regs *regs)
 182 {
 183         unsigned long clone_flags;
 184         unsigned long newsp;
 185
 186         /* syscall2 puts clone_flags in d1 and usp in d2 */
 187         clone_flags = regs->d1;
 188         newsp = regs->d2;
 189         if (!newsp)
 190                 newsp = rdusp();
 191         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 192 }
 193
 194 int copy_thread(int nr, unsigned long clone_flags,
 195                 unsigned long usp, unsigned long topstk,
 196                 struct task_struct * p, struct pt_regs * regs)
 197 {
 198         struct pt_regs * childregs;
 199         struct switch_stack * childstack, *stack;
 200         unsigned long stack_offset, *retp;
 201
 202         stack_offset = THREAD_SIZE - sizeof(struct pt_regs);
 203         childregs = (struct pt_regs *) ((unsigned long) p->thread_info + stack_offset);
 204
 205         *childregs = *regs;
 206         childregs->d0 = 0;
 207
 208         retp = ((unsigned long *) regs);
 209         stack = ((struct switch_stack *) retp) - 1;
 210
 211         childstack = ((struct switch_stack *) childregs) - 1;
 212         *childstack = *stack;
 213         childstack->retpc = (unsigned long)ret_from_fork;
 214
 215         p->thread.usp = usp;
 216         p->thread.ksp = (unsigned long)childstack;
 217         /*
 218          * Must save the current SFC/DFC value, NOT the value when
 219          * the parent was last descheduled - RGH  10-08-96
 220          */
 221         p->thread.fs = get_fs().seg;
 222
 223 #ifdef CONFIG_FPU
 224         if (!FPU_IS_EMU) {
 225                 /* Copy the current fpu state */
 226                 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
 227
 228                 if (p->thread.fpstate[0])
 229                   asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
 230                                 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
 231                                 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
 232                                 : "memory");
 233                 /* Restore the state in case the fpu was busy */
 234                 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
 235         }
 236 #endif
 237
 238         return 0;
 239 }
 240
 241 /* Fill in the fpu structure for a core dump.  */
 242
 243 int dump_fpu(struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 244 {
 245 #ifdef CONFIG_FPU
 246         char fpustate[216];
 247
 248         if (FPU_IS_EMU) {
 249                 int i;
 250
 251                 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
 252                 memcpy(fpu->fpregs, current->thread.fp, 96);
 253                 /* Convert internal fpu reg representation
 254                  * into long double format
 255                  */
 256                 for (i = 0; i < 24; i += 3)
 257                         fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
 258                                          ((fpu->fpregs[i] & 0x0000ffff) << 16);
 259                 return 1;
 260         }
 261
 262         /* First dump the fpu context to avoid protocol violation.  */
 263         asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
 264         if (!fpustate[0])
 265                 return 0;
 266
 267         asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
 268                 :: "m" (fpu->fpcntl[0])
 269                 : "memory");
 270         asm volatile ("fmovemx %/fp0-%/fp7,%0"
 271                 :: "m" (fpu->fpregs[0])
 272                 : "memory");
 273 #endif
 274         return 1;
 275 }
 276
 277 /*
 278  * fill in the user structure for a core dump..
 279  */
 280 void dump_thread(struct pt_regs * regs, struct user * dump)
 281 {
 282         struct switch_stack *sw;
 283
 284         /* changed the size calculations - should hopefully work better. lbt */
 285         dump->magic = CMAGIC;
 286         dump->start_code = 0;
 287         dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
 288         dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
 289         dump->u_dsize = ((unsigned long) (current->mm->brk +
 290                                           (PAGE_SIZE-1))) >> PAGE_SHIFT;
 291         dump->u_dsize -= dump->u_tsize;
 292         dump->u_ssize = 0;
 293
 294         if (dump->start_stack < TASK_SIZE)
 295                 dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
 296
 297         dump->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump);
 298         sw = ((struct switch_stack *)regs) - 1;
 299         dump->regs.d1 = regs->d1;
 300         dump->regs.d2 = regs->d2;
 301         dump->regs.d3 = regs->d3;
 302         dump->regs.d4 = regs->d4;
 303         dump->regs.d5 = regs->d5;
 304         dump->regs.d6 = sw->d6;
 305         dump->regs.d7 = sw->d7;
 306         dump->regs.a0 = regs->a0;
 307         dump->regs.a1 = regs->a1;
 308         dump->regs.a2 = regs->a2;
 309         dump->regs.a3 = sw->a3;
 310         dump->regs.a4 = sw->a4;
 311         dump->regs.a5 = sw->a5;
 312         dump->regs.a6 = sw->a6;
 313         dump->regs.d0 = regs->d0;
 314         dump->regs.orig_d0 = regs->orig_d0;
 315         dump->regs.stkadj = regs->stkadj;
 316         dump->regs.sr = regs->sr;
 317         dump->regs.pc = regs->pc;
 318         dump->regs.fmtvec = (regs->format << 12) | regs->vector;
 319         /* dump floating point stuff */
 320         dump->u_fpvalid = dump_fpu (regs, &dump->m68kfp);
 321 }
 322
 323 /*
 324  *      Generic dumping code. Used for panic and debug.
 325  */
 326 void dump(struct pt_regs *fp)
 327 {
 328         unsigned long   *sp;
 329         unsigned char   *tp;
 330         int             i;
 331
 332         printk(KERN_EMERG "\nCURRENT PROCESS:\n\n");
 333         printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);
 334
 335         if (current->mm) {
 336                 printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 337                         (int) current->mm->start_code,
 338                         (int) current->mm->end_code,
 339                         (int) current->mm->start_data,
 340                         (int) current->mm->end_data,
 341                         (int) current->mm->end_data,
 342                         (int) current->mm->brk);
 343                 printk(KERN_EMERG "USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 344                         (int) current->mm->start_stack,
 345                         (int)(((unsigned long) current) + THREAD_SIZE));
 346         }
 347
 348         printk(KERN_EMERG "PC: %08lx\n", fp->pc);
 349         printk(KERN_EMERG "SR: %08lx    SP: %08lx\n", (long) fp->sr, (long) fp);
 350         printk(KERN_EMERG "d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 351                 fp->d0, fp->d1, fp->d2, fp->d3);
 352         printk(KERN_EMERG "d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 353                 fp->d4, fp->d5, fp->a0, fp->a1);
 354         printk(KERN_EMERG "\nUSP: %08x   TRAPFRAME: %08x\n", (unsigned int) rdusp(),
 355                 (unsigned int) fp);
 356
 357         printk(KERN_EMERG "\nCODE:");
 358         tp = ((unsigned char *) fp->pc) - 0x20;
 359         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 360                 if ((i % 0x10) == 0)
 361                         printk(KERN_EMERG "\n%08x: ", (int) (tp + i));
 362                 printk(KERN_EMERG "%08x ", (int) *sp++);
 363         }
 364         printk(KERN_EMERG "\n");
 365
 366         printk(KERN_EMERG "\nKERNEL STACK:");
 367         tp = ((unsigned char *) fp) - 0x40;
 368         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 369                 if ((i % 0x10) == 0)
 370                         printk(KERN_EMERG "\n%08x: ", (int) (tp + i));
 371                 printk(KERN_EMERG "%08x ", (int) *sp++);
 372         }
 373         printk(KERN_EMERG "\n");
 374         printk(KERN_EMERG "\n");
 375
 376         printk(KERN_EMERG "\nUSER STACK:");
 377         tp = (unsigned char *) (rdusp() - 0x10);
 378         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 379                 if ((i % 0x10) == 0)
 380                         printk(KERN_EMERG "\n%08x: ", (int) (tp + i));
 381                 printk(KERN_EMERG "%08x ", (int) *sp++);
 382         }
 383         printk(KERN_EMERG "\n\n");
 384 }
 385
 386 /*
 387  * sys_execve() executes a new program.
 388  */
 389 asmlinkage int sys_execve(char *name, char **argv, char **envp)
 390 {
 391         int error;
 392         char * filename;
 393         struct pt_regs *regs = (struct pt_regs *) &name;
 394
 395         lock_kernel();
 396         filename = getname(name);
 397         error = PTR_ERR(filename);
 398         if (IS_ERR(filename))
 399                 goto out;
 400         error = do_execve(filename, argv, envp, regs);
 401         putname(filename);
 402 out:
 403         unlock_kernel();
 404         return error;
 405 }
 406
 407 unsigned long get_wchan(struct task_struct *p)
 408 {
 409         unsigned long fp, pc;
 410         unsigned long stack_page;
 411         int count = 0;
 412         if (!p || p == current || p->state == TASK_RUNNING)
 413                 return 0;
 414
 415         stack_page = (unsigned long)p;
 416         fp = ((struct switch_stack *)p->thread.ksp)->a6;
 417         do {
 418                 if (fp < stack_page+sizeof(struct thread_info) ||
 419                     fp >= 8184+stack_page)
 420                         return 0;
 421                 pc = ((unsigned long *)fp)[1];
 422                 if (!in_sched_functions(pc))
 423                         return pc;
 424                 fp = *(unsigned long *) fp;
 425         } while (count++ < 16);
 426         return 0;
 427 }
 428
 429 /*
 430  * Return saved PC of a blocked thread.
 431  */
 432 unsigned long thread_saved_pc(struct task_struct *tsk)
 433 {
 434         struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
 435
 436         /* Check whether the thread is blocked in resume() */
 437         if (in_sched_functions(sw->retpc))
 438                 return ((unsigned long *)sw->a6)[1];
 439         else
 440                 return sw->retpc;
 441 }
 442