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,
  48                   const char *const argv[],
  49                   const char *const envp[])
  50 {
  51         register long __res asm ("%d0") = __NR_execve;
  52         register long __a asm ("%d1") = (long)(filename);
  53         register long __b asm ("%d2") = (long)(argv);
  54         register long __c asm ("%d3") = (long)(envp);
  55         asm volatile ("trap  #0" : "+d" (__res)
  56                         : "d" (__a), "d" (__b), "d" (__c));
  57         return __res;
  58 }
  59
  60 asmlinkage unsigned long sys_get_thread_area(void)
  61 {
  62         return current_thread_info()->tp_value;
  63 }
  64
  65 asmlinkage int sys_set_thread_area(unsigned long tp)
  66 {
  67         current_thread_info()->tp_value = tp;
  68         return 0;
  69 }
  70
  71 /* This syscall gets its arguments in A0 (mem), D2 (oldval) and
  72    D1 (newval).  */
  73 asmlinkage int
  74 sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
  75                       unsigned long __user * mem)
  76 {
  77         struct mm_struct *mm = current->mm;
  78         unsigned long mem_value;
  79
  80         down_read(&mm->mmap_sem);
  81
  82         mem_value = *mem;
  83         if (mem_value == oldval)
  84                 *mem = newval;
  85
  86         up_read(&mm->mmap_sem);
  87         return mem_value;
  88 }
  89
  90 asmlinkage int sys_atomic_barrier(void)
  91 {
  92         /* no code needed for uniprocs */
  93         return 0;
  94 }