1/*
  2 * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
  3 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  4 *
  5 *   This program is free software; you can redistribute it and/or
  6 *   modify it under the terms of the GNU General Public License
  7 *   as published by the Free Software Foundation, version 2.
  8 *
  9 *   This program is distributed in the hope that it will be useful, but
 10 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 11 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 12 *   NON INFRINGEMENT.  See the GNU General Public License for
 13 *   more details.
 14 *
 15 * See asm-generic/syscall.h for descriptions of what we must do here.
 16 */
 17
 18#ifndef _ASM_TILE_SYSCALL_H
 19#define _ASM_TILE_SYSCALL_H
 20
 21#include <linux/sched.h>
 22#include <linux/err.h>
 23#include <linux/audit.h>
 24#include <linux/compat.h>
 25#include <arch/abi.h>
 26
 27/* The array of function pointers for syscalls. */
 28extern void *sys_call_table[];
 29#ifdef CONFIG_COMPAT
 30extern void *compat_sys_call_table[];
 31#endif
 32
 33/*
 34 * Only the low 32 bits of orig_r0 are meaningful, so we return int.
 35 * This importantly ignores the high bits on 64-bit, so comparisons
 36 * sign-extend the low 32 bits.
 37 */
 38static inline int syscall_get_nr(struct task_struct *t, struct pt_regs *regs)
 39{
 40	return regs->regs[TREG_SYSCALL_NR];
 41}
 42
 43static inline void syscall_rollback(struct task_struct *task,
 44				    struct pt_regs *regs)
 45{
 46	regs->regs[0] = regs->orig_r0;
 47}
 48
 49static inline long syscall_get_error(struct task_struct *task,
 50				     struct pt_regs *regs)
 51{
 52	unsigned long error = regs->regs[0];
 53	return IS_ERR_VALUE(error) ? error : 0;
 54}
 55
 56static inline long syscall_get_return_value(struct task_struct *task,
 57					    struct pt_regs *regs)
 58{
 59	return regs->regs[0];
 60}
 61
 62static inline void syscall_set_return_value(struct task_struct *task,
 63					    struct pt_regs *regs,
 64					    int error, long val)
 65{
 66	if (error) {
 67		/* R0 is the passed-in negative error, R1 is positive. */
 68		regs->regs[0] = error;
 69		regs->regs[1] = -error;
 70	} else {
 71		/* R1 set to zero to indicate no error. */
 72		regs->regs[0] = val;
 73		regs->regs[1] = 0;
 74	}
 75}
 76
 77static inline void syscall_get_arguments(struct task_struct *task,
 78					 struct pt_regs *regs,
 79					 unsigned int i, unsigned int n,
 80					 unsigned long *args)
 81{
 82	BUG_ON(i + n > 6);
 83	memcpy(args, &regs[i], n * sizeof(args[0]));
 84}
 85
 86static inline void syscall_set_arguments(struct task_struct *task,
 87					 struct pt_regs *regs,
 88					 unsigned int i, unsigned int n,
 89					 const unsigned long *args)
 90{
 91	BUG_ON(i + n > 6);
 92	memcpy(&regs[i], args, n * sizeof(args[0]));
 93}
 94
 95/*
 96 * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
 97 * tile has the same system calls both on little- and big- endian.
 98 */
 99static inline int syscall_get_arch(void)
100{
101	if (is_compat_task())
102		return AUDIT_ARCH_TILEGX32;
103
104#ifdef CONFIG_TILEGX
105	return AUDIT_ARCH_TILEGX;
106#else
107	return AUDIT_ARCH_TILEPRO;
108#endif
109}
110
111#endif	/* _ASM_TILE_SYSCALL_H */