arch/m68k/kernel/process_mm.c

   1 /*
   2  *  linux/arch/m68k/kernel/process.c
   3  *
   4  *  Copyright (C) 1995  Hamish Macdonald
   5  *
   6  *  68060 fixes by Jesper Skov
   7  */
   8
   9 /*
  10  * This file handles the architecture-dependent parts of process handling..
  11  */
  12
  13 #include <linux/errno.h>
  14 #include <linux/module.h>
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/mm.h>
  18 #include <linux/slab.h>
  19 #include <linux/fs.h>
  20 #include <linux/smp.h>
  21 #include <linux/stddef.h>
  22 #include <linux/unistd.h>
  23 #include <linux/ptrace.h>
  24 #include <linux/user.h>
  25 #include <linux/reboot.h>
  26 #include <linux/init_task.h>
  27 #include <linux/mqueue.h>
  28
  29 #include <asm/uaccess.h>
  30 #include <asm/system.h>
  31 #include <asm/traps.h>
  32 #include <asm/machdep.h>
  33 #include <asm/setup.h>
  34 #include <asm/pgtable.h>
  35
  36
  37 asmlinkage void ret_from_fork(void);
  38
  39
  40 /*
  41  * Return saved PC from a blocked thread
  42  */
  43 unsigned long thread_saved_pc(struct task_struct *tsk)
  44 {
  45         struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
  46         /* Check whether the thread is blocked in resume() */
  47         if (in_sched_functions(sw->retpc))
  48                 return ((unsigned long *)sw->a6)[1];
  49         else
  50                 return sw->retpc;
  51 }
  52
  53 /*
  54  * The idle loop on an m68k..
  55  */
  56 static void default_idle(void)
  57 {
  58         if (!need_resched())
  59 #if defined(MACH_ATARI_ONLY)
  60                 /* block out HSYNC on the atari (falcon) */
  61                 __asm__("stop #0x2200" : : : "cc");
  62 #else
  63                 __asm__("stop #0x2000" : : : "cc");
  64 #endif
  65 }
  66
  67 void (*idle)(void) = default_idle;
  68
  69 /*
  70  * The idle thread. There's no useful work to be
  71  * done, so just try to conserve power and have a
  72  * low exit latency (ie sit in a loop waiting for
  73  * somebody to say that they'd like to reschedule)
  74  */
  75 void cpu_idle(void)
  76 {
  77         /* endless idle loop with no priority at all */
  78         while (1) {
  79                 while (!need_resched())
  80                         idle();
  81                 preempt_enable_no_resched();
  82                 schedule();
  83                 preempt_disable();
  84         }
  85 }
  86
  87 void machine_restart(char * __unused)
  88 {
  89         if (mach_reset)
  90                 mach_reset();
  91         for (;;);
  92 }
  93
  94 void machine_halt(void)
  95 {
  96         if (mach_halt)
  97                 mach_halt();
  98         for (;;);
  99 }
 100
 101 void machine_power_off(void)
 102 {
 103         if (mach_power_off)
 104                 mach_power_off();
 105         for (;;);
 106 }
 107
 108 void (*pm_power_off)(void) = machine_power_off;
 109 EXPORT_SYMBOL(pm_power_off);
 110
 111 void show_regs(struct pt_regs * regs)
 112 {
 113         printk("\n");
 114         printk("Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
 115                regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
 116         printk("ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
 117                regs->orig_d0, regs->d0, regs->a2, regs->a1);
 118         printk("A0: %08lx  D5: %08lx  D4: %08lx\n",
 119                regs->a0, regs->d5, regs->d4);
 120         printk("D3: %08lx  D2: %08lx  D1: %08lx\n",
 121                regs->d3, regs->d2, regs->d1);
 122         if (!(regs->sr & PS_S))
 123                 printk("USP: %08lx\n", rdusp());
 124 }
 125
 126 /*
 127  * Create a kernel thread
 128  */
 129 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 130 {
 131         int pid;
 132         mm_segment_t fs;
 133
 134         fs = get_fs();
 135         set_fs (KERNEL_DS);
 136
 137         {
 138         register long retval __asm__ ("d0");
 139         register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
 140
 141         retval = __NR_clone;
 142         __asm__ __volatile__
 143           ("clrl %%d2\n\t"
 144            "trap #0\n\t"                /* Linux/m68k system call */
 145            "tstl %0\n\t"                /* child or parent */
 146            "jne 1f\n\t"                 /* parent - jump */
 147            "lea %%sp@(%c7),%6\n\t"      /* reload current */
 148            "movel %6@,%6\n\t"
 149            "movel %3,%%sp@-\n\t"        /* push argument */
 150            "jsr %4@\n\t"                /* call fn */
 151            "movel %0,%%d1\n\t"          /* pass exit value */
 152            "movel %2,%%d0\n\t"          /* exit */
 153            "trap #0\n"
 154            "1:"
 155            : "+d" (retval)
 156            : "i" (__NR_clone), "i" (__NR_exit),
 157              "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
 158              "i" (-THREAD_SIZE)
 159            : "d2");
 160
 161         pid = retval;
 162         }
 163
 164         set_fs (fs);
 165         return pid;
 166 }
 167 EXPORT_SYMBOL(kernel_thread);
 168
 169 void flush_thread(void)
 170 {
 171         unsigned long zero = 0;
 172
 173         current->thread.fs = __USER_DS;
 174         if (!FPU_IS_EMU)
 175                 asm volatile("frestore %0": :"m" (zero));
 176 }
 177
 178 /*
 179  * "m68k_fork()".. By the time we get here, the
 180  * non-volatile registers have also been saved on the
 181  * stack. We do some ugly pointer stuff here.. (see
 182  * also copy_thread)
 183  */
 184
 185 asmlinkage int m68k_fork(struct pt_regs *regs)
 186 {
 187         return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 188 }
 189
 190 asmlinkage int m68k_vfork(struct pt_regs *regs)
 191 {
 192         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
 193                        NULL, NULL);
 194 }
 195
 196 asmlinkage int m68k_clone(struct pt_regs *regs)
 197 {
 198         unsigned long clone_flags;
 199         unsigned long newsp;
 200         int __user *parent_tidptr, *child_tidptr;
 201
 202         /* syscall2 puts clone_flags in d1 and usp in d2 */
 203         clone_flags = regs->d1;
 204         newsp = regs->d2;
 205         parent_tidptr = (int __user *)regs->d3;
 206         child_tidptr = (int __user *)regs->d4;
 207         if (!newsp)
 208                 newsp = rdusp();
 209         return do_fork(clone_flags, newsp, regs, 0,
 210                        parent_tidptr, child_tidptr);
 211 }
 212
 213 int copy_thread(unsigned long clone_flags, unsigned long usp,
 214                  unsigned long unused,
 215                  struct task_struct * p, struct pt_regs * regs)
 216 {
 217         struct pt_regs * childregs;
 218         struct switch_stack * childstack, *stack;
 219         unsigned long *retp;
 220
 221         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
 222
 223         *childregs = *regs;
 224         childregs->d0 = 0;
 225
 226         retp = ((unsigned long *) regs);
 227         stack = ((struct switch_stack *) retp) - 1;
 228
 229         childstack = ((struct switch_stack *) childregs) - 1;
 230         *childstack = *stack;
 231         childstack->retpc = (unsigned long)ret_from_fork;
 232
 233         p->thread.usp = usp;
 234         p->thread.ksp = (unsigned long)childstack;
 235
 236         if (clone_flags & CLONE_SETTLS)
 237                 task_thread_info(p)->tp_value = regs->d5;
 238
 239         /*
 240          * Must save the current SFC/DFC value, NOT the value when
 241          * the parent was last descheduled - RGH  10-08-96
 242          */
 243         p->thread.fs = get_fs().seg;
 244
 245         if (!FPU_IS_EMU) {
 246                 /* Copy the current fpu state */
 247                 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
 248
 249                 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
 250                         if (CPU_IS_COLDFIRE) {
 251                                 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
 252                                               "fmovel %/fpiar,%1\n\t"
 253                                               "fmovel %/fpcr,%2\n\t"
 254                                               "fmovel %/fpsr,%3"
 255                                               :
 256                                               : "m" (p->thread.fp[0]),
 257                                                 "m" (p->thread.fpcntl[0]),
 258                                                 "m" (p->thread.fpcntl[1]),
 259                                                 "m" (p->thread.fpcntl[2])
 260                                               : "memory");
 261                         } else {
 262                                 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
 263                                               "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
 264                                               :
 265                                               : "m" (p->thread.fp[0]),
 266                                                 "m" (p->thread.fpcntl[0])
 267                                               : "memory");
 268                         }
 269                 }
 270
 271                 /* Restore the state in case the fpu was busy */
 272                 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
 273         }
 274
 275         return 0;
 276 }
 277
 278 /* Fill in the fpu structure for a core dump.  */
 279
 280 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 281 {
 282         char fpustate[216];
 283
 284         if (FPU_IS_EMU) {
 285                 int i;
 286
 287                 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
 288                 memcpy(fpu->fpregs, current->thread.fp, 96);
 289                 /* Convert internal fpu reg representation
 290                  * into long double format
 291                  */
 292                 for (i = 0; i < 24; i += 3)
 293                         fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
 294                                          ((fpu->fpregs[i] & 0x0000ffff) << 16);
 295                 return 1;
 296         }
 297
 298         /* First dump the fpu context to avoid protocol violation.  */
 299         asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
 300         if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
 301                 return 0;
 302
 303         if (CPU_IS_COLDFIRE) {
 304                 asm volatile ("fmovel %/fpiar,%0\n\t"
 305                               "fmovel %/fpcr,%1\n\t"
 306                               "fmovel %/fpsr,%2\n\t"
 307                               "fmovemd %/fp0-%/fp7,%3"
 308                               :
 309                               : "m" (fpu->fpcntl[0]),
 310                                 "m" (fpu->fpcntl[1]),
 311                                 "m" (fpu->fpcntl[2]),
 312                                 "m" (fpu->fpregs[0])
 313                               : "memory");
 314         } else {
 315                 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
 316                               :
 317                               : "m" (fpu->fpcntl[0])
 318                               : "memory");
 319                 asm volatile ("fmovemx %/fp0-%/fp7,%0"
 320                               :
 321                               : "m" (fpu->fpregs[0])
 322                               : "memory");
 323         }
 324
 325         return 1;
 326 }
 327 EXPORT_SYMBOL(dump_fpu);
 328
 329 /*
 330  * sys_execve() executes a new program.
 331  */
 332 asmlinkage int sys_execve(const char __user *name,
 333                           const char __user *const __user *argv,
 334                           const char __user *const __user *envp)
 335 {
 336         int error;
 337         char * filename;
 338         struct pt_regs *regs = (struct pt_regs *) &name;
 339
 340         filename = getname(name);
 341         error = PTR_ERR(filename);
 342         if (IS_ERR(filename))
 343                 return error;
 344         error = do_execve(filename, argv, envp, regs);
 345         putname(filename);
 346         return error;
 347 }
 348
 349 unsigned long get_wchan(struct task_struct *p)
 350 {
 351         unsigned long fp, pc;
 352         unsigned long stack_page;
 353         int count = 0;
 354         if (!p || p == current || p->state == TASK_RUNNING)
 355                 return 0;
 356
 357         stack_page = (unsigned long)task_stack_page(p);
 358         fp = ((struct switch_stack *)p->thread.ksp)->a6;
 359         do {
 360                 if (fp < stack_page+sizeof(struct thread_info) ||
 361                     fp >= 8184+stack_page)
 362                         return 0;
 363                 pc = ((unsigned long *)fp)[1];
 364                 if (!in_sched_functions(pc))
 365                         return pc;
 366                 fp = *(unsigned long *) fp;
 367         } while (count++ < 16);
 368         return 0;
 369 }