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 #include <linux/fs.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  * The following aren't currently used.
  44  */
  45 void (*pm_idle)(void);
  46 EXPORT_SYMBOL(pm_idle);
  47
  48 void (*pm_power_off)(void);
  49 EXPORT_SYMBOL(pm_power_off);
  50
  51 /*
  52  * The idle loop on an m68knommu..
  53  */
  54 static void default_idle(void)
  55 {
  56         local_irq_disable();
  57         while (!need_resched()) {
  58                 /* This stop will re-enable interrupts */
  59                 __asm__("stop #0x2000" : : : "cc");
  60                 local_irq_disable();
  61         }
  62         local_irq_enable();
  63 }
  64
  65 void (*idle)(void) = default_idle;
  66
  67 /*
  68  * The idle thread. There's no useful work to be
  69  * done, so just try to conserve power and have a
  70  * low exit latency (ie sit in a loop waiting for
  71  * somebody to say that they'd like to reschedule)
  72  */
  73 void cpu_idle(void)
  74 {
  75         /* endless idle loop with no priority at all */
  76         while (1) {
  77                 idle();
  78                 preempt_enable_no_resched();
  79                 schedule();
  80                 preempt_disable();
  81         }
  82 }
  83
  84 void machine_restart(char * __unused)
  85 {
  86         if (mach_reset)
  87                 mach_reset();
  88         for (;;);
  89 }
  90
  91 void machine_halt(void)
  92 {
  93         if (mach_halt)
  94                 mach_halt();
  95         for (;;);
  96 }
  97
  98 void machine_power_off(void)
  99 {
 100         if (mach_power_off)
 101                 mach_power_off();
 102         for (;;);
 103 }
 104
 105 void show_regs(struct pt_regs * regs)
 106 {
 107         printk(KERN_NOTICE "\n");
 108         printk(KERN_NOTICE "Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
 109                regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
 110         printk(KERN_NOTICE "ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
 111                regs->orig_d0, regs->d0, regs->a2, regs->a1);
 112         printk(KERN_NOTICE "A0: %08lx  D5: %08lx  D4: %08lx\n",
 113                regs->a0, regs->d5, regs->d4);
 114         printk(KERN_NOTICE "D3: %08lx  D2: %08lx  D1: %08lx\n",
 115                regs->d3, regs->d2, regs->d1);
 116         if (!(regs->sr & PS_S))
 117                 printk(KERN_NOTICE "USP: %08lx\n", rdusp());
 118 }
 119
 120 /*
 121  * Create a kernel thread
 122  */
 123 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 124 {
 125         int retval;
 126         long clone_arg = flags | CLONE_VM;
 127         mm_segment_t fs;
 128
 129         fs = get_fs();
 130         set_fs(KERNEL_DS);
 131
 132         __asm__ __volatile__ (
 133                         "movel  %%sp, %%d2\n\t"
 134                         "movel  %5, %%d1\n\t"
 135                         "movel  %1, %%d0\n\t"
 136                         "trap   #0\n\t"
 137                         "cmpl   %%sp, %%d2\n\t"
 138                         "jeq    1f\n\t"
 139                         "movel  %3, %%sp@-\n\t"
 140                         "jsr    %4@\n\t"
 141                         "movel  %2, %%d0\n\t"
 142                         "trap   #0\n"
 143                         "1:\n\t"
 144                         "movel  %%d0, %0\n"
 145                 : "=d" (retval)
 146                 : "i" (__NR_clone),
 147                   "i" (__NR_exit),
 148                   "a" (arg),
 149                   "a" (fn),
 150                   "a" (clone_arg)
 151                 : "cc", "%d0", "%d1", "%d2");
 152
 153         set_fs(fs);
 154         return retval;
 155 }
 156
 157 void flush_thread(void)
 158 {
 159 #ifdef CONFIG_FPU
 160         unsigned long zero = 0;
 161 #endif
 162         set_fs(USER_DS);
 163         current->thread.fs = __USER_DS;
 164 #ifdef CONFIG_FPU
 165         if (!FPU_IS_EMU)
 166                 asm volatile (".chip 68k/68881\n\t"
 167                               "frestore %0@\n\t"
 168                               ".chip 68k" : : "a" (&zero));
 169 #endif
 170 }
 171
 172 /*
 173  * "m68k_fork()".. By the time we get here, the
 174  * non-volatile registers have also been saved on the
 175  * stack. We do some ugly pointer stuff here.. (see
 176  * also copy_thread)
 177  */
 178
 179 asmlinkage int m68k_fork(struct pt_regs *regs)
 180 {
 181         /* fork almost works, enough to trick you into looking elsewhere :-( */
 182         return(-EINVAL);
 183 }
 184
 185 asmlinkage int m68k_vfork(struct pt_regs *regs)
 186 {
 187         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 188 }
 189
 190 asmlinkage int m68k_clone(struct pt_regs *regs)
 191 {
 192         unsigned long clone_flags;
 193         unsigned long newsp;
 194
 195         /* syscall2 puts clone_flags in d1 and usp in d2 */
 196         clone_flags = regs->d1;
 197         newsp = regs->d2;
 198         if (!newsp)
 199                 newsp = rdusp();
 200         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 201 }
 202
 203 int copy_thread(int nr, unsigned long clone_flags,
 204                 unsigned long usp, unsigned long topstk,
 205                 struct task_struct * p, struct pt_regs * regs)
 206 {
 207         struct pt_regs * childregs;
 208         struct switch_stack * childstack, *stack;
 209         unsigned long *retp;
 210
 211         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
 212
 213         *childregs = *regs;
 214         childregs->d0 = 0;
 215
 216         retp = ((unsigned long *) regs);
 217         stack = ((struct switch_stack *) retp) - 1;
 218
 219         childstack = ((struct switch_stack *) childregs) - 1;
 220         *childstack = *stack;
 221         childstack->retpc = (unsigned long)ret_from_fork;
 222
 223         p->thread.usp = usp;
 224         p->thread.ksp = (unsigned long)childstack;
 225         /*
 226          * Must save the current SFC/DFC value, NOT the value when
 227          * the parent was last descheduled - RGH  10-08-96
 228          */
 229         p->thread.fs = get_fs().seg;
 230
 231 #ifdef CONFIG_FPU
 232         if (!FPU_IS_EMU) {
 233                 /* Copy the current fpu state */
 234                 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
 235
 236                 if (p->thread.fpstate[0])
 237                   asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
 238                                 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
 239                                 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
 240                                 : "memory");
 241                 /* Restore the state in case the fpu was busy */
 242                 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
 243         }
 244 #endif
 245
 246         return 0;
 247 }
 248
 249 /* Fill in the fpu structure for a core dump.  */
 250
 251 int dump_fpu(struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 252 {
 253 #ifdef CONFIG_FPU
 254         char fpustate[216];
 255
 256         if (FPU_IS_EMU) {
 257                 int i;
 258
 259                 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
 260                 memcpy(fpu->fpregs, current->thread.fp, 96);
 261                 /* Convert internal fpu reg representation
 262                  * into long double format
 263                  */
 264                 for (i = 0; i < 24; i += 3)
 265                         fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
 266                                          ((fpu->fpregs[i] & 0x0000ffff) << 16);
 267                 return 1;
 268         }
 269
 270         /* First dump the fpu context to avoid protocol violation.  */
 271         asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
 272         if (!fpustate[0])
 273                 return 0;
 274
 275         asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
 276                 :: "m" (fpu->fpcntl[0])
 277                 : "memory");
 278         asm volatile ("fmovemx %/fp0-%/fp7,%0"
 279                 :: "m" (fpu->fpregs[0])
 280                 : "memory");
 281 #endif
 282         return 1;
 283 }
 284
 285 /*
 286  *      Generic dumping code. Used for panic and debug.
 287  */
 288 void dump(struct pt_regs *fp)
 289 {
 290         unsigned long   *sp;
 291         unsigned char   *tp;
 292         int             i;
 293
 294         printk(KERN_EMERG "\n" KERN_EMERG "CURRENT PROCESS:\n" KERN_EMERG "\n");
 295         printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);
 296
 297         if (current->mm) {
 298                 printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 299                         (int) current->mm->start_code,
 300                         (int) current->mm->end_code,
 301                         (int) current->mm->start_data,
 302                         (int) current->mm->end_data,
 303                         (int) current->mm->end_data,
 304                         (int) current->mm->brk);
 305                 printk(KERN_EMERG "USER-STACK=%08x KERNEL-STACK=%08x\n"
 306                         KERN_EMERG "\n",
 307                         (int) current->mm->start_stack,
 308                         (int)(((unsigned long) current) + THREAD_SIZE));
 309         }
 310
 311         printk(KERN_EMERG "PC: %08lx\n", fp->pc);
 312         printk(KERN_EMERG "SR: %08lx    SP: %08lx\n", (long) fp->sr, (long) fp);
 313         printk(KERN_EMERG "d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 314                 fp->d0, fp->d1, fp->d2, fp->d3);
 315         printk(KERN_EMERG "d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 316                 fp->d4, fp->d5, fp->a0, fp->a1);
 317         printk(KERN_EMERG "\n" KERN_EMERG "USP: %08x   TRAPFRAME: %08x\n",
 318                 (unsigned int) rdusp(), (unsigned int) fp);
 319
 320         printk(KERN_EMERG "\n" KERN_EMERG "CODE:");
 321         tp = ((unsigned char *) fp->pc) - 0x20;
 322         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 323                 if ((i % 0x10) == 0)
 324                         printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
 325                 printk("%08x ", (int) *sp++);
 326         }
 327         printk("\n" KERN_EMERG "\n");
 328
 329         printk(KERN_EMERG "KERNEL STACK:");
 330         tp = ((unsigned char *) fp) - 0x40;
 331         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 332                 if ((i % 0x10) == 0)
 333                         printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
 334                 printk("%08x ", (int) *sp++);
 335         }
 336         printk("\n" KERN_EMERG "\n");
 337
 338         printk(KERN_EMERG "USER STACK:");
 339         tp = (unsigned char *) (rdusp() - 0x10);
 340         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 341                 if ((i % 0x10) == 0)
 342                         printk("\n" KERN_EMERG "%08x: ", (int) (tp + i));
 343                 printk("%08x ", (int) *sp++);
 344         }
 345         printk("\n" KERN_EMERG "\n");
 346 }
 347
 348 /*
 349  * sys_execve() executes a new program.
 350  */
 351 asmlinkage int sys_execve(char *name, char **argv, char **envp)
 352 {
 353         int error;
 354         char * filename;
 355         struct pt_regs *regs = (struct pt_regs *) &name;
 356
 357         lock_kernel();
 358         filename = getname(name);
 359         error = PTR_ERR(filename);
 360         if (IS_ERR(filename))
 361                 goto out;
 362         error = do_execve(filename, argv, envp, regs);
 363         putname(filename);
 364 out:
 365         unlock_kernel();
 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