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/smp_lock.h>
  23 #include <linux/stddef.h>
  24 #include <linux/unistd.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/slab.h>
  27 #include <linux/user.h>
  28 #include <linux/a.out.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/reboot.h>
  31
  32 #include <asm/uaccess.h>
  33 #include <asm/system.h>
  34 #include <asm/traps.h>
  35 #include <asm/machdep.h>
  36 #include <asm/setup.h>
  37 #include <asm/pgtable.h>
  38
  39 asmlinkage void ret_from_fork(void);
  40
  41 /*
  42  * The following aren't currently used.
  43  */
  44 void (*pm_idle)(void);
  45 EXPORT_SYMBOL(pm_idle);
  46
  47 void (*pm_power_off)(void);
  48 EXPORT_SYMBOL(pm_power_off);
  49
  50 /*
  51  * The idle loop on an m68knommu..
  52  */
  53 static void default_idle(void)
  54 {
  55         local_irq_disable();
  56         while (!need_resched()) {
  57                 /* This stop will re-enable interrupts */
  58                 __asm__("stop #0x2000" : : : "cc");
  59                 local_irq_disable();
  60         }
  61         local_irq_enable();
  62 }
  63
  64 void (*idle)(void) = default_idle;
  65
  66 /*
  67  * The idle thread. There's no useful work to be
  68  * done, so just try to conserve power and have a
  69  * low exit latency (ie sit in a loop waiting for
  70  * somebody to say that they'd like to reschedule)
  71  */
  72 void cpu_idle(void)
  73 {
  74         /* endless idle loop with no priority at all */
  75         while (1) {
  76                 idle();
  77                 preempt_enable_no_resched();
  78                 schedule();
  79                 preempt_disable();
  80         }
  81 }
  82
  83 void machine_restart(char * __unused)
  84 {
  85         if (mach_reset)
  86                 mach_reset();
  87         for (;;);
  88 }
  89
  90 void machine_halt(void)
  91 {
  92         if (mach_halt)
  93                 mach_halt();
  94         for (;;);
  95 }
  96
  97 void machine_power_off(void)
  98 {
  99         if (mach_power_off)
 100                 mach_power_off();
 101         for (;;);
 102 }
 103
 104 void show_regs(struct pt_regs * regs)
 105 {
 106         printk(KERN_NOTICE "\n");
 107         printk(KERN_NOTICE "Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
 108                regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
 109         printk(KERN_NOTICE "ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
 110                regs->orig_d0, regs->d0, regs->a2, regs->a1);
 111         printk(KERN_NOTICE "A0: %08lx  D5: %08lx  D4: %08lx\n",
 112                regs->a0, regs->d5, regs->d4);
 113         printk(KERN_NOTICE "D3: %08lx  D2: %08lx  D1: %08lx\n",
 114                regs->d3, regs->d2, regs->d1);
 115         if (!(regs->sr & PS_S))
 116                 printk(KERN_NOTICE "USP: %08lx\n", rdusp());
 117 }
 118
 119 /*
 120  * Create a kernel thread
 121  */
 122 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 123 {
 124         int retval;
 125         long clone_arg = flags | CLONE_VM;
 126         mm_segment_t fs;
 127
 128         fs = get_fs();
 129         set_fs(KERNEL_DS);
 130
 131         __asm__ __volatile__ (
 132                         "movel  %%sp, %%d2\n\t"
 133                         "movel  %5, %%d1\n\t"
 134                         "movel  %1, %%d0\n\t"
 135                         "trap   #0\n\t"
 136                         "cmpl   %%sp, %%d2\n\t"
 137                         "jeq    1f\n\t"
 138                         "movel  %3, %%sp@-\n\t"
 139                         "jsr    %4@\n\t"
 140                         "movel  %2, %%d0\n\t"
 141                         "trap   #0\n"
 142                         "1:\n\t"
 143                         "movel  %%d0, %0\n"
 144                 : "=d" (retval)
 145                 : "i" (__NR_clone),
 146                   "i" (__NR_exit),
 147                   "a" (arg),
 148                   "a" (fn),
 149                   "a" (clone_arg)
 150                 : "cc", "%d0", "%d1", "%d2");
 151
 152         set_fs(fs);
 153         return retval;
 154 }
 155
 156 void flush_thread(void)
 157 {
 158 #ifdef CONFIG_FPU
 159         unsigned long zero = 0;
 160 #endif
 161         set_fs(USER_DS);
 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(int nr, 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          * 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  *      Generic dumping code. Used for panic and debug.
 286  */
 287 void dump(struct pt_regs *fp)
 288 {
 289         unsigned long   *sp;
 290         unsigned char   *tp;
 291         int             i;
 292
 293         printk(KERN_EMERG "\n" KERN_EMERG "CURRENT PROCESS:\n" KERN_EMERG "\n");
 294         printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);
 295
 296         if (current->mm) {
 297                 printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 298                         (int) current->mm->start_code,
 299                         (int) current->mm->end_code,
 300                         (int) current->mm->start_data,
 301                         (int) current->mm->end_data,
 302                         (int) current->mm->end_data,
 303                         (int) current->mm->brk);
 304                 printk(KERN_EMERG "USER-STACK=%08x KERNEL-STACK=%08x\n"
 305                         KERN_EMERG "\n",
 306                         (int) current->mm->start_stack,
 307                         (int)(((unsigned long) current) + THREAD_SIZE));
 308         }
 309
 310         printk(KERN_EMERG "PC: %08lx\n", fp->pc);
 311         printk(KERN_EMERG "SR: %08lx    SP: %08lx\n", (long) fp->sr, (long) fp);
 312         printk(KERN_EMERG "d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 313                 fp->d0, fp->d1, fp->d2, fp->d3);
 314         printk(KERN_EMERG "d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 315                 fp->d4, fp->d5, fp->a0, fp->a1);
 316         printk(KERN_EMERG "\n" KERN_EMERG "USP: %08x   TRAPFRAME: %08x\n",
 317                 (unsigned int) rdusp(), (unsigned int) fp);
 318
 319         printk(KERN_EMERG "\n" KERN_EMERG "CODE:");
 320         tp = ((unsigned char *) fp->pc) - 0x20;
 321         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 322                 if ((i % 0x10) == 0)
 323                         printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
 324                 printk("%08x ", (int) *sp++);
 325         }
 326         printk("\n" KERN_EMERG "\n");
 327
 328         printk(KERN_EMERG "KERNEL STACK:");
 329         tp = ((unsigned char *) fp) - 0x40;
 330         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 331                 if ((i % 0x10) == 0)
 332                         printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
 333                 printk("%08x ", (int) *sp++);
 334         }
 335         printk("\n" KERN_EMERG "\n");
 336
 337         printk(KERN_EMERG "USER STACK:");
 338         tp = (unsigned char *) (rdusp() - 0x10);
 339         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 340                 if ((i % 0x10) == 0)
 341                         printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
 342                 printk("%08x ", (int) *sp++);
 343         }
 344         printk("\n" KERN_EMERG "\n");
 345 }
 346
 347 /*
 348  * sys_execve() executes a new program.
 349  */
 350 asmlinkage int sys_execve(char *name, char **argv, char **envp)
 351 {
 352         int error;
 353         char * filename;
 354         struct pt_regs *regs = (struct pt_regs *) &name;
 355
 356         lock_kernel();
 357         filename = getname(name);
 358         error = PTR_ERR(filename);
 359         if (IS_ERR(filename))
 360                 goto out;
 361         error = do_execve(filename, argv, envp, regs);
 362         putname(filename);
 363 out:
 364         unlock_kernel();
 365         return error;
 366 }
 367
 368 unsigned long get_wchan(struct task_struct *p)
 369 {
 370         unsigned long fp, pc;
 371         unsigned long stack_page;
 372         int count = 0;
 373         if (!p || p == current || p->state == TASK_RUNNING)
 374                 return 0;
 375
 376         stack_page = (unsigned long)p;
 377         fp = ((struct switch_stack *)p->thread.ksp)->a6;
 378         do {
 379                 if (fp < stack_page+sizeof(struct thread_info) ||
 380                     fp >= 8184+stack_page)
 381                         return 0;
 382                 pc = ((unsigned long *)fp)[1];
 383                 if (!in_sched_functions(pc))
 384                         return pc;
 385                 fp = *(unsigned long *) fp;
 386         } while (count++ < 16);
 387         return 0;
 388 }
 389
 390 /*
 391  * Return saved PC of a blocked thread.
 392  */
 393 unsigned long thread_saved_pc(struct task_struct *tsk)
 394 {
 395         struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
 396
 397         /* Check whether the thread is blocked in resume() */
 398         if (in_sched_functions(sw->retpc))
 399                 return ((unsigned long *)sw->a6)[1];
 400         else
 401                 return sw->retpc;
 402 }
 403