1/*
  2 *  arch/s390/kernel/sys_s390.c
  3 *
  4 *  S390 version
  5 *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
  6 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
  7 *               Thomas Spatzier (tspat@de.ibm.com)
  8 *
  9 *  Derived from "arch/i386/kernel/sys_i386.c"
 10 *
 11 *  This file contains various random system calls that
 12 *  have a non-standard calling sequence on the Linux/s390
 13 *  platform.
 14 */
 15
 16#include <linux/errno.h>
 17#include <linux/sched.h>
 18#include <linux/mm.h>
 19#include <linux/fs.h>
 20#include <linux/smp.h>
 21#include <linux/sem.h>
 22#include <linux/msg.h>
 23#include <linux/shm.h>
 24#include <linux/stat.h>
 25#include <linux/syscalls.h>
 26#include <linux/mman.h>
 27#include <linux/file.h>
 28#include <linux/utsname.h>
 29#include <linux/personality.h>
 30#include <linux/unistd.h>
 31#include <linux/ipc.h>
 32#include <asm/uaccess.h>
 33#include "entry.h"
 34
 35/*
 36 * Perform the mmap() system call. Linux for S/390 isn't able to handle more
 37 * than 5 system call parameters, so this system call uses a memory block
 38 * for parameter passing.
 39 */
 40
 41struct s390_mmap_arg_struct {
 42	unsigned long addr;
 43	unsigned long len;
 44	unsigned long prot;
 45	unsigned long flags;
 46	unsigned long fd;
 47	unsigned long offset;
 48};
 49
 50SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
 51{
 52	struct s390_mmap_arg_struct a;
 53	int error = -EFAULT;
 54
 55	if (copy_from_user(&a, arg, sizeof(a)))
 56		goto out;
 57	error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
 58out:
 59	return error;
 60}
 61
 62/*
 63 * sys_ipc() is the de-multiplexer for the SysV IPC calls.
 64 */
 65SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
 66		unsigned long, third, void __user *, ptr)
 67{
 68	if (call >> 16)
 69		return -EINVAL;
 70	/* The s390 sys_ipc variant has only five parameters instead of six
 71	 * like the generic variant. The only difference is the handling of
 72	 * the SEMTIMEDOP subcall where on s390 the third parameter is used
 73	 * as a pointer to a struct timespec where the generic variant uses
 74	 * the fifth parameter.
 75	 * Therefore we can call the generic variant by simply passing the
 76	 * third parameter also as fifth parameter.
 77	 */
 78	return sys_ipc(call, first, second, third, ptr, third);
 79}
 80
 81#ifdef CONFIG_64BIT
 82SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
 83{
 84	unsigned int ret;
 85
 86	if (current->personality == PER_LINUX32 && personality == PER_LINUX)
 87		personality = PER_LINUX32;
 88	ret = sys_personality(personality);
 89	if (ret == PER_LINUX32)
 90		ret = PER_LINUX;
 91
 92	return ret;
 93}
 94#endif /* CONFIG_64BIT */
 95
 96/*
 97 * Wrapper function for sys_fadvise64/fadvise64_64
 98 */
 99#ifndef CONFIG_64BIT
100
101SYSCALL_DEFINE5(s390_fadvise64, int, fd, u32, offset_high, u32, offset_low,
102		size_t, len, int, advice)
103{
104	return sys_fadvise64(fd, (u64) offset_high << 32 | offset_low,
105			len, advice);
106}
107
108struct fadvise64_64_args {
109	int fd;
110	long long offset;
111	long long len;
112	int advice;
113};
114
115SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, args)
116{
117	struct fadvise64_64_args a;
118
119	if ( copy_from_user(&a, args, sizeof(a)) )
120		return -EFAULT;
121	return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
122}
123
124/*
125 * This is a wrapper to call sys_fallocate(). For 31 bit s390 the last
126 * 64 bit argument "len" is split into the upper and lower 32 bits. The
127 * system call wrapper in the user space loads the value to %r6/%r7.
128 * The code in entry.S keeps the values in %r2 - %r6 where they are and
129 * stores %r7 to 96(%r15). But the standard C linkage requires that
130 * the whole 64 bit value for len is stored on the stack and doesn't
131 * use %r6 at all. So s390_fallocate has to convert the arguments from
132 *   %r2: fd, %r3: mode, %r4/%r5: offset, %r6/96(%r15)-99(%r15): len
133 * to
134 *   %r2: fd, %r3: mode, %r4/%r5: offset, 96(%r15)-103(%r15): len
135 */
136SYSCALL_DEFINE(s390_fallocate)(int fd, int mode, loff_t offset,
137			       u32 len_high, u32 len_low)
138{
139	return sys_fallocate(fd, mode, offset, ((u64)len_high << 32) | len_low);
140}
141#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
142asmlinkage long SyS_s390_fallocate(long fd, long mode, loff_t offset,
143				   long len_high, long len_low)
144{
145	return SYSC_s390_fallocate((int) fd, (int) mode, offset,
146				   (u32) len_high, (u32) len_low);
147}
148SYSCALL_ALIAS(sys_s390_fallocate, SyS_s390_fallocate);
149#endif
150
151#endif