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                 schedule_preempt_disabled();
  77         }
  78 }
  79
  80 void machine_restart(char * __unused)
  81 {
  82         if (mach_reset)
  83                 mach_reset();
  84         for (;;);
  85 }
  86
  87 void machine_halt(void)
  88 {
  89         if (mach_halt)
  90                 mach_halt();
  91         for (;;);
  92 }
  93
  94 void machine_power_off(void)
  95 {
  96         if (mach_power_off)
  97                 mach_power_off();
  98         for (;;);
  99 }
 100
 101 void show_regs(struct pt_regs * regs)
 102 {
 103         printk(KERN_NOTICE "\n");
 104         printk(KERN_NOTICE "Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
 105                regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
 106         printk(KERN_NOTICE "ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
 107                regs->orig_d0, regs->d0, regs->a2, regs->a1);
 108         printk(KERN_NOTICE "A0: %08lx  D5: %08lx  D4: %08lx\n",
 109                regs->a0, regs->d5, regs->d4);
 110         printk(KERN_NOTICE "D3: %08lx  D2: %08lx  D1: %08lx\n",
 111                regs->d3, regs->d2, regs->d1);
 112         if (!(regs->sr & PS_S))
 113                 printk(KERN_NOTICE "USP: %08lx\n", rdusp());
 114 }
 115
 116 /*
 117  * Create a kernel thread
 118  */
 119 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 120 {
 121         int retval;
 122         long clone_arg = flags | CLONE_VM;
 123         mm_segment_t fs;
 124
 125         fs = get_fs();
 126         set_fs(KERNEL_DS);
 127
 128         __asm__ __volatile__ (
 129                         "movel  %%sp, %%d2\n\t"
 130                         "movel  %5, %%d1\n\t"
 131                         "movel  %1, %%d0\n\t"
 132                         "trap   #0\n\t"
 133                         "cmpl   %%sp, %%d2\n\t"
 134                         "jeq    1f\n\t"
 135                         "movel  %3, %%sp@-\n\t"
 136                         "jsr    %4@\n\t"
 137                         "movel  %2, %%d0\n\t"
 138                         "trap   #0\n"
 139                         "1:\n\t"
 140                         "movel  %%d0, %0\n"
 141                 : "=d" (retval)
 142                 : "i" (__NR_clone),
 143                   "i" (__NR_exit),
 144                   "a" (arg),
 145                   "a" (fn),
 146                   "a" (clone_arg)
 147                 : "cc", "%d0", "%d1", "%d2");
 148
 149         set_fs(fs);
 150         return retval;
 151 }
 152 EXPORT_SYMBOL(kernel_thread);
 153
 154 void flush_thread(void)
 155 {
 156 #ifdef CONFIG_FPU
 157         unsigned long zero = 0;
 158 #endif
 159
 160         current->thread.fs = __USER_DS;
 161 #ifdef CONFIG_FPU
 162         if (!FPU_IS_EMU)
 163                 asm volatile (".chip 68k/68881\n\t"
 164                               "frestore %0\n\t"
 165                               ".chip 68k" : : "m" (zero));
 166 #endif
 167 }
 168
 169 /*
 170  * "m68k_fork()".. By the time we get here, the
 171  * non-volatile registers have also been saved on the
 172  * stack. We do some ugly pointer stuff here.. (see
 173  * also copy_thread)
 174  */
 175
 176 asmlinkage int m68k_fork(struct pt_regs *regs)
 177 {
 178         /* fork almost works, enough to trick you into looking elsewhere :-( */
 179         return(-EINVAL);
 180 }
 181
 182 asmlinkage int m68k_vfork(struct pt_regs *regs)
 183 {
 184         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 185 }
 186
 187 asmlinkage int m68k_clone(struct pt_regs *regs)
 188 {
 189         unsigned long clone_flags;
 190         unsigned long newsp;
 191
 192         /* syscall2 puts clone_flags in d1 and usp in d2 */
 193         clone_flags = regs->d1;
 194         newsp = regs->d2;
 195         if (!newsp)
 196                 newsp = rdusp();
 197         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 198 }
 199
 200 int copy_thread(unsigned long clone_flags,
 201                 unsigned long usp, unsigned long topstk,
 202                 struct task_struct * p, struct pt_regs * regs)
 203 {
 204         struct pt_regs * childregs;
 205         struct switch_stack * childstack, *stack;
 206         unsigned long *retp;
 207
 208         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
 209
 210         *childregs = *regs;
 211         childregs->d0 = 0;
 212
 213         retp = ((unsigned long *) regs);
 214         stack = ((struct switch_stack *) retp) - 1;
 215
 216         childstack = ((struct switch_stack *) childregs) - 1;
 217         *childstack = *stack;
 218         childstack->retpc = (unsigned long)ret_from_fork;
 219
 220         p->thread.usp = usp;
 221         p->thread.ksp = (unsigned long)childstack;
 222
 223         if (clone_flags & CLONE_SETTLS)
 224                 task_thread_info(p)->tp_value = regs->d5;
 225
 226         /*
 227          * Must save the current SFC/DFC value, NOT the value when
 228          * the parent was last descheduled - RGH  10-08-96
 229          */
 230         p->thread.fs = get_fs().seg;
 231
 232 #ifdef CONFIG_FPU
 233         if (!FPU_IS_EMU) {
 234                 /* Copy the current fpu state */
 235                 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
 236
 237                 if (p->thread.fpstate[0])
 238                   asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
 239                                 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
 240                                 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
 241                                 : "memory");
 242                 /* Restore the state in case the fpu was busy */
 243                 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
 244         }
 245 #endif
 246
 247         return 0;
 248 }
 249
 250 /* Fill in the fpu structure for a core dump.  */
 251
 252 int dump_fpu(struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 253 {
 254 #ifdef CONFIG_FPU
 255         char fpustate[216];
 256
 257         if (FPU_IS_EMU) {
 258                 int i;
 259
 260                 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
 261                 memcpy(fpu->fpregs, current->thread.fp, 96);
 262                 /* Convert internal fpu reg representation
 263                  * into long double format
 264                  */
 265                 for (i = 0; i < 24; i += 3)
 266                         fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
 267                                          ((fpu->fpregs[i] & 0x0000ffff) << 16);
 268                 return 1;
 269         }
 270
 271         /* First dump the fpu context to avoid protocol violation.  */
 272         asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
 273         if (!fpustate[0])
 274                 return 0;
 275
 276         asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
 277                 :: "m" (fpu->fpcntl[0])
 278                 : "memory");
 279         asm volatile ("fmovemx %/fp0-%/fp7,%0"
 280                 :: "m" (fpu->fpregs[0])
 281                 : "memory");
 282 #endif
 283         return 1;
 284 }
 285 EXPORT_SYMBOL(dump_fpu);
 286
 287 /*
 288  *      Generic dumping code. Used for panic and debug.
 289  */
 290 void dump(struct pt_regs *fp)
 291 {
 292         unsigned long   *sp;
 293         unsigned char   *tp;
 294         int             i;
 295
 296         printk(KERN_EMERG "\nCURRENT PROCESS:\n\n");
 297         printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);
 298
 299         if (current->mm) {
 300                 printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 301                         (int) current->mm->start_code,
 302                         (int) current->mm->end_code,
 303                         (int) current->mm->start_data,
 304                         (int) current->mm->end_data,
 305                         (int) current->mm->end_data,
 306                         (int) current->mm->brk);
 307                 printk(KERN_EMERG "USER-STACK=%08x KERNEL-STACK=%08x\n\n",
 308                         (int) current->mm->start_stack,
 309                         (int)(((unsigned long) current) + THREAD_SIZE));
 310         }
 311
 312         printk(KERN_EMERG "PC: %08lx\n", fp->pc);
 313         printk(KERN_EMERG "SR: %08lx    SP: %08lx\n", (long) fp->sr, (long) fp);
 314         printk(KERN_EMERG "d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 315                 fp->d0, fp->d1, fp->d2, fp->d3);
 316         printk(KERN_EMERG "d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 317                 fp->d4, fp->d5, fp->a0, fp->a1);
 318         printk(KERN_EMERG "\nUSP: %08x   TRAPFRAME: %p\n",
 319                 (unsigned int) rdusp(), fp);
 320
 321         printk(KERN_EMERG "\nCODE:");
 322         tp = ((unsigned char *) fp->pc) - 0x20;
 323         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 324                 if ((i % 0x10) == 0)
 325                         printk(KERN_EMERG "%p: ", tp + i);
 326                 printk("%08x ", (int) *sp++);
 327         }
 328         printk(KERN_EMERG "\n");
 329
 330         printk(KERN_EMERG "KERNEL STACK:");
 331         tp = ((unsigned char *) fp) - 0x40;
 332         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 333                 if ((i % 0x10) == 0)
 334                         printk(KERN_EMERG "%p: ", tp + i);
 335                 printk("%08x ", (int) *sp++);
 336         }
 337         printk(KERN_EMERG "\n");
 338
 339         printk(KERN_EMERG "USER STACK:");
 340         tp = (unsigned char *) (rdusp() - 0x10);
 341         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 342                 if ((i % 0x10) == 0)
 343                         printk(KERN_EMERG "%p: ", tp + i);
 344                 printk("%08x ", (int) *sp++);
 345         }
 346         printk(KERN_EMERG "\n");
 347 }
 348
 349 /*
 350  * sys_execve() executes a new program.
 351  */
 352 asmlinkage int sys_execve(const char *name,
 353                           const char *const *argv,
 354                           const char *const *envp)
 355 {
 356         int error;
 357         char * filename;
 358         struct pt_regs *regs = (struct pt_regs *) &name;
 359
 360         filename = getname(name);
 361         error = PTR_ERR(filename);
 362         if (IS_ERR(filename))
 363                 return error;
 364         error = do_execve(filename, argv, envp, regs);
 365         putname(filename);
 366         return error;
 367 }
 368
 369 unsigned long get_wchan(struct task_struct *p)
 370 {
 371         unsigned long fp, pc;
 372         unsigned long stack_page;
 373         int count = 0;
 374         if (!p || p == current || p->state == TASK_RUNNING)
 375                 return 0;
 376
 377         stack_page = (unsigned long)p;
 378         fp = ((struct switch_stack *)p->thread.ksp)->a6;
 379         do {
 380                 if (fp < stack_page+sizeof(struct thread_info) ||
 381                     fp >= THREAD_SIZE-8+stack_page)
 382                         return 0;
 383                 pc = ((unsigned long *)fp)[1];
 384                 if (!in_sched_functions(pc))
 385                         return pc;
 386                 fp = *(unsigned long *) fp;
 387         } while (count++ < 16);
 388         return 0;
 389 }
 390
 391 /*
 392  * Return saved PC of a blocked thread.
 393  */
 394 unsigned long thread_saved_pc(struct task_struct *tsk)
 395 {
 396         struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
 397
 398         /* Check whether the thread is blocked in resume() */
 399         if (in_sched_functions(sw->retpc))
 400                 return ((unsigned long *)sw->a6)[1];
 401         else
 402                 return sw->retpc;
 403 }
 404