linux/arch/m68knommu/kernel/sys_m68k.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_ipc() is the de-multiplexer for the SysV IPC calls..
 *
 * This is really horribly ugly.
 */
asmlinkage int sys_ipc (uint call, int first, int second,
			int third, void *ptr, long fifth)
{
	int version, ret;

	version = call >> 16; /* hack for backward compatibility */
	call &= 0xffff;

	if (call <= SEMCTL)
		switch (call) {
		case SEMOP:
			return sys_semop (first, (struct sembuf *)ptr, second);
		case SEMGET:
			return sys_semget (first, second, third);
		case SEMCTL: {
			union semun fourth;
			if (!ptr)
				return -EINVAL;
			if (get_user(fourth.__pad, (void **) ptr))
				return -EFAULT;
			return sys_semctl (first, second, third, fourth);
			}
		default:
			return -EINVAL;
		}
	if (call <= MSGCTL) 
		switch (call) {
		case MSGSND:
			return sys_msgsnd (first, (struct msgbuf *) ptr, 
					  second, third);
		case MSGRCV:
			switch (version) {
			case 0: {
				struct ipc_kludge tmp;
				if (!ptr)
					return -EINVAL;
				if (copy_from_user (&tmp,
						    (struct ipc_kludge *)ptr,
						    sizeof (tmp)))
					return -EFAULT;
				return sys_msgrcv (first, tmp.msgp, second,
						   tmp.msgtyp, third);
				}
			default:
				return sys_msgrcv (first,
						   (struct msgbuf *) ptr,
						   second, fifth, third);
			}
		case MSGGET:
			return sys_msgget ((key_t) first, second);
		case MSGCTL:
			return sys_msgctl (first, second,
					   (struct msqid_ds *) ptr);
		default:
			return -EINVAL;
		}
	if (call <= SHMCTL)
		switch (call) {
		case SHMAT:
			switch (version) {
			default: {
				ulong raddr;
				ret = do_shmat (first, ptr, second, &raddr);
				if (ret)
					return ret;
				return put_user (raddr, (ulong __user *) third);
			}
			}
		case SHMDT:
			return sys_shmdt (ptr);
		case SHMGET:
			return sys_shmget (first, second, third);
		case SHMCTL:
			return sys_shmctl (first, second, ptr);
		default:
			return -ENOSYS;
		}

	return -EINVAL;
}

/* 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, char *const argv[], 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;
}