m68k: merge the mmu and non-mmu versions of sys_m68k.c

There is a lot of common code in the sys_m68k.c files. The mmu and non-mmu
versions can easily be merged into a single file.

There is really only 2 functions that differ in the 2 cases. A single
ifdef on CONFIG_MMU can take care of this. Alternatively we could break
those 2 functions out and maintain sys_m68k_no.c and sys_m68k_mm.c with
just this code in it (Makefile could then just build the right one).
Does anyone have strong feelings on which way they want this done?
Signed-off-by: Greg Ungerer <gerg@uclinux.org>

arch/m68k/kernel/sys_m68k_no.c

-/*
- * linux/arch/m68knommu/kernel/sys_m68k.c
- *
- * This file contains various random system calls that
- * have a non-standard calling sequence on the Linux/m68k
- * platform.
- */
-
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/sem.h>
-#include <linux/msg.h>
-#include <linux/shm.h>
-#include <linux/stat.h>
-#include <linux/syscalls.h>
-#include <linux/mman.h>
-#include <linux/file.h>
-#include <linux/ipc.h>
-#include <linux/fs.h>
-
-#include <asm/setup.h>
-#include <asm/uaccess.h>
-#include <asm/cachectl.h>
-#include <asm/traps.h>
-#include <asm/cacheflush.h>
-#include <asm/unistd.h>
-
-/* sys_cacheflush -- flush (part of) the processor cache.  */
-asmlinkage int
-sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
-{
-	flush_cache_all();
-	return(0);
-}
-
-asmlinkage int sys_getpagesize(void)
-{
-	return PAGE_SIZE;
-}
-
-/*
- * Do a system call from kernel instead of calling sys_execve so we
- * end up with proper pt_regs.
- */
-int kernel_execve(const char *filename,
-		  const char *const argv[],
-		  const char *const envp[])
-{
-	register long __res asm ("%d0") = __NR_execve;
-	register long __a asm ("%d1") = (long)(filename);
-	register long __b asm ("%d2") = (long)(argv);
-	register long __c asm ("%d3") = (long)(envp);
-	asm volatile ("trap  #0" : "+d" (__res)
-			: "d" (__a), "d" (__b), "d" (__c));
-	return __res;
-}
-
-asmlinkage unsigned long sys_get_thread_area(void)
-{
-	return current_thread_info()->tp_value;
-}
-
-asmlinkage int sys_set_thread_area(unsigned long tp)
-{
-	current_thread_info()->tp_value = tp;
-	return 0;
-}
-
-/* This syscall gets its arguments in A0 (mem), D2 (oldval) and
-   D1 (newval).  */
-asmlinkage int
-sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
-		      unsigned long __user * mem)
-{
-	struct mm_struct *mm = current->mm;
-	unsigned long mem_value;
-
-	down_read(&mm->mmap_sem);
-
-	mem_value = *mem;
-	if (mem_value == oldval)
-		*mem = newval;
-
-	up_read(&mm->mmap_sem);
-	return mem_value;
-}
-
-asmlinkage int sys_atomic_barrier(void)
-{
-	/* no code needed for uniprocs */
-	return 0;
-}