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/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
 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(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 *retp;
 208
 209         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
 210
 211         *childregs = *regs;
 212         childregs->d0 = 0;
 213
 214         retp = ((unsigned long *) regs);
 215         stack = ((struct switch_stack *) retp) - 1;
 216
 217         childstack = ((struct switch_stack *) childregs) - 1;
 218         *childstack = *stack;
 219         childstack->retpc = (unsigned long)ret_from_fork;
 220
 221         p->thread.usp = usp;
 222         p->thread.ksp = (unsigned long)childstack;
 223
 224         if (clone_flags & CLONE_SETTLS)
 225                 task_thread_info(p)->tp_value = regs->d5;
 226
 227         /*
 228          * Must save the current SFC/DFC value, NOT the value when
 229          * the parent was last descheduled - RGH  10-08-96
 230          */
 231         p->thread.fs = get_fs().seg;
 232
 233 #ifdef CONFIG_FPU
 234         if (!FPU_IS_EMU) {
 235                 /* Copy the current fpu state */
 236                 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
 237
 238                 if (p->thread.fpstate[0])
 239                   asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
 240                                 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
 241                                 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
 242                                 : "memory");
 243                 /* Restore the state in case the fpu was busy */
 244                 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
 245         }
 246 #endif
 247
 248         return 0;
 249 }
 250
 251 /* Fill in the fpu structure for a core dump.  */
 252
 253 int dump_fpu(struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 254 {
 255 #ifdef CONFIG_FPU
 256         char fpustate[216];
 257
 258         if (FPU_IS_EMU) {
 259                 int i;
 260
 261                 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
 262                 memcpy(fpu->fpregs, current->thread.fp, 96);
 263                 /* Convert internal fpu reg representation
 264                  * into long double format
 265                  */
 266                 for (i = 0; i < 24; i += 3)
 267                         fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
 268                                          ((fpu->fpregs[i] & 0x0000ffff) << 16);
 269                 return 1;
 270         }
 271
 272         /* First dump the fpu context to avoid protocol violation.  */
 273         asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
 274         if (!fpustate[0])
 275                 return 0;
 276
 277         asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
 278                 :: "m" (fpu->fpcntl[0])
 279                 : "memory");
 280         asm volatile ("fmovemx %/fp0-%/fp7,%0"
 281                 :: "m" (fpu->fpregs[0])
 282                 : "memory");
 283 #endif
 284         return 1;
 285 }
 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