arch/m68knommu/kernel/sys_m68k.c

   1 /*
   2  * linux/arch/m68knommu/kernel/sys_m68k.c
   3  *
   4  * This file contains various random system calls that
   5  * have a non-standard calling sequence on the Linux/m68k
   6  * platform.
   7  */
   8
   9 #include <linux/errno.h>
  10 #include <linux/sched.h>
  11 #include <linux/mm.h>
  12 #include <linux/smp.h>
  13 #include <linux/sem.h>
  14 #include <linux/msg.h>
  15 #include <linux/shm.h>
  16 #include <linux/stat.h>
  17 #include <linux/syscalls.h>
  18 #include <linux/mman.h>
  19 #include <linux/file.h>
  20 #include <linux/ipc.h>
  21 #include <linux/fs.h>
  22
  23 #include <asm/setup.h>
  24 #include <asm/uaccess.h>
  25 #include <asm/cachectl.h>
  26 #include <asm/traps.h>
  27 #include <asm/cacheflush.h>
  28 #include <asm/unistd.h>
  29
  30 /* sys_cacheflush -- flush (part of) the processor cache.  */
  31 asmlinkage int
  32 sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
  33 {
  34         flush_cache_all();
  35         return(0);
  36 }
  37
  38 asmlinkage int sys_getpagesize(void)
  39 {
  40         return PAGE_SIZE;
  41 }
  42
  43 /*
  44  * Do a system call from kernel instead of calling sys_execve so we
  45  * end up with proper pt_regs.
  46  */
  47 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
  48 {
  49         register long __res asm ("%d0") = __NR_execve;
  50         register long __a asm ("%d1") = (long)(filename);
  51         register long __b asm ("%d2") = (long)(argv);
  52         register long __c asm ("%d3") = (long)(envp);
  53         asm volatile ("trap  #0" : "+d" (__res)
  54                         : "d" (__a), "d" (__b), "d" (__c));
  55         return __res;
  56 }
  57
  58 asmlinkage unsigned long sys_get_thread_area(void)
  59 {
  60         return current_thread_info()->tp_value;
  61 }
  62
  63 asmlinkage int sys_set_thread_area(unsigned long tp)
  64 {
  65         current_thread_info()->tp_value = tp;
  66         return 0;
  67 }
  68
  69 /* This syscall gets its arguments in A0 (mem), D2 (oldval) and
  70    D1 (newval).  */
  71 asmlinkage int
  72 sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
  73                       unsigned long __user * mem)
  74 {
  75         struct mm_struct *mm = current->mm;
  76         unsigned long mem_value;
  77
  78         down_read(&mm->mmap_sem);
  79
  80         mem_value = *mem;
  81         if (mem_value == oldval)
  82                 *mem = newval;
  83
  84         up_read(&mm->mmap_sem);
  85         return mem_value;
  86 }
  87
  88 asmlinkage int sys_atomic_barrier(void)
  89 {
  90         /* no code needed for uniprocs */
  91         return 0;
  92 }