/*
 *  arch/s390/kernel/sys_s390.c
 *
 *  S390 version
 *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
 *               Thomas Spatzier (tspat@de.ibm.com)
 *
 *  Derived from "arch/i386/kernel/sys_i386.c"
 *
 *  This file contains various random system calls that
 *  have a non-standard calling sequence on the Linux/s390
 *  platform.
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fs.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/utsname.h>
#include <linux/personality.h>
#include <linux/unistd.h>
#include <linux/ipc.h>
#include <linux/syscalls.h>
#include <asm/uaccess.h>
#include "entry.h"

/* common code for old and new mmaps */
static inline long do_mmap2(
        unsigned long addr, unsigned long len,
        unsigned long prot, unsigned long flags,
        unsigned long fd, unsigned long pgoff)
{
        long error = -EBADF;
        struct file * file = NULL;

        flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
        if (!(flags & MAP_ANONYMOUS)) {
                file = fget(fd);
                if (!file)
                        goto out;
        }

        down_write(&current->mm->mmap_sem);
        error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
        up_write(&current->mm->mmap_sem);

        if (file)
                fput(file);
out:
        return error;
}

/*
 * Perform the select(nd, in, out, ex, tv) and mmap() system
 * calls. Linux for S/390 isn't able to handle more than 5
 * system call parameters, so these system calls used a memory
 * block for parameter passing..
 */

struct mmap_arg_struct {
        unsigned long addr;
        unsigned long len;
        unsigned long prot;
        unsigned long flags;
        unsigned long fd;
        unsigned long offset;
};

SYSCALL_DEFINE1(mmap2, struct mmap_arg_struct __user *, arg)
{
        struct mmap_arg_struct a;
        int error = -EFAULT;

        if (copy_from_user(&a, arg, sizeof(a)))
                goto out;
        error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
out:
        return error;
}

SYSCALL_DEFINE1(s390_old_mmap, struct mmap_arg_struct __user *, arg)
{
        struct mmap_arg_struct a;
        long error = -EFAULT;

        if (copy_from_user(&a, arg, sizeof(a)))
                goto out;

        error = -EINVAL;
        if (a.offset & ~PAGE_MASK)
                goto out;

        error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
out:
        return error;
}

/*
 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 *
 * This is really horribly ugly.
 */
SYSCALL_DEFINE5(ipc, uint, call, int, first, unsigned long, second,
                unsigned long, third, void __user *, ptr)
{
        struct ipc_kludge tmp;
        int ret;

        switch (call) {
        case SEMOP:
                return sys_semtimedop(first, (struct sembuf __user *)ptr,
                                       (unsigned)second, NULL);
        case SEMTIMEDOP:
                return sys_semtimedop(first, (struct sembuf __user *)ptr,
                                       (unsigned)second,
                                       (const struct timespec __user *) third);
        case SEMGET:
                return sys_semget(first, (int)second, third);
        case SEMCTL: {
                union semun fourth;
                if (!ptr)
                        return -EINVAL;
                if (get_user(fourth.__pad, (void __user * __user *) ptr))
                        return -EFAULT;
                return sys_semctl(first, (int)second, third, fourth);
        }
        case MSGSND:
                return sys_msgsnd (first, (struct msgbuf __user *) ptr,
                                   (size_t)second, third);
                break;
        case MSGRCV:
                if (!ptr)
                        return -EINVAL;
                if (copy_from_user (&tmp, (struct ipc_kludge __user *) ptr,
                                    sizeof (struct ipc_kludge)))
                        return -EFAULT;
                return sys_msgrcv (first, tmp.msgp,
                                   (size_t)second, tmp.msgtyp, third);
        case MSGGET:
                return sys_msgget((key_t)first, (int)second);
        case MSGCTL:
                return sys_msgctl(first, (int)second,
                                   (struct msqid_ds __user *)ptr);

        case SHMAT: {
                ulong raddr;
                ret = do_shmat(first, (char __user *)ptr,
                                (int)second, &raddr);
                if (ret)
                        return ret;
                return put_user (raddr, (ulong __user *) third);
                break;
        }
        case SHMDT:
                return sys_shmdt ((char __user *)ptr);
        case SHMGET:
                return sys_shmget(first, (size_t)second, third);
        case SHMCTL:
                return sys_shmctl(first, (int)second,
                                   (struct shmid_ds __user *) ptr);
        default:
                return -ENOSYS;

        }

        return -EINVAL;
}

#ifdef CONFIG_64BIT
SYSCALL_DEFINE1(s390_newuname, struct new_utsname __user *, name)
{
        int ret = sys_newuname(name);

        if (personality(current->personality) == PER_LINUX32 && !ret) {
                ret = copy_to_user(name->machine, "s390\0\0\0\0", 8);
                if (ret) ret = -EFAULT;
        }
        return ret;
}

SYSCALL_DEFINE1(s390_personality, unsigned long, personality)
{
        int ret;

        if (current->personality == PER_LINUX32 && personality == PER_LINUX)
                personality = PER_LINUX32;
        ret = sys_personality(personality);
        if (ret == PER_LINUX32)
                ret = PER_LINUX;

        return ret;
}
#endif /* CONFIG_64BIT */

/*
 * Wrapper function for sys_fadvise64/fadvise64_64
 */
#ifndef CONFIG_64BIT

SYSCALL_DEFINE5(s390_fadvise64, int, fd, u32, offset_high, u32, offset_low,
                size_t, len, int, advice)
{
        return sys_fadvise64(fd, (u64) offset_high << 32 | offset_low,
                        len, advice);
}

struct fadvise64_64_args {
        int fd;
        long long offset;
        long long len;
        int advice;
};

SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, args)
{
        struct fadvise64_64_args a;

        if ( copy_from_user(&a, args, sizeof(a)) )
                return -EFAULT;
        return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
}

/*
 * This is a wrapper to call sys_fallocate(). For 31 bit s390 the last
 * 64 bit argument "len" is split into the upper and lower 32 bits. The
 * system call wrapper in the user space loads the value to %r6/%r7.
 * The code in entry.S keeps the values in %r2 - %r6 where they are and
 * stores %r7 to 96(%r15). But the standard C linkage requires that
 * the whole 64 bit value for len is stored on the stack and doesn't
 * use %r6 at all. So s390_fallocate has to convert the arguments from
 *   %r2: fd, %r3: mode, %r4/%r5: offset, %r6/96(%r15)-99(%r15): len
 * to
 *   %r2: fd, %r3: mode, %r4/%r5: offset, 96(%r15)-103(%r15): len
 */
SYSCALL_DEFINE(s390_fallocate)(int fd, int mode, loff_t offset,
                               u32 len_high, u32 len_low)
{
        return sys_fallocate(fd, mode, offset, ((u64)len_high << 32) | len_low);
}
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
asmlinkage long SyS_s390_fallocate(long fd, long mode, loff_t offset,
                                   long len_high, long len_low)
{
        return SYSC_s390_fallocate((int) fd, (int) mode, offset,
                                   (u32) len_high, (u32) len_low);
}
SYSCALL_ALIAS(sys_s390_fallocate, SyS_s390_fallocate);
#endif

#endif