/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2007 Maciej W. Rozycki
* Copyright (C) 2014, Imagination Technologies Ltd.
*/
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/thread_info.h>
#include <linux/string.h>
#include <asm/asm-eva.h>
/*
* The fs value determines whether argument validity checking should be
* performed or not. If get_fs() == USER_DS, checking is performed, with
* get_fs() == KERNEL_DS, checking is bypassed.
*
* For historical reasons, these macros are grossly misnamed.
*/
#ifdef CONFIG_32BIT
#ifdef CONFIG_KVM_GUEST
#define __UA_LIMIT 0x40000000UL
#else
#define __UA_LIMIT 0x80000000UL
#endif
#define __UA_ADDR ".word"
#define __UA_LA "la"
#define __UA_ADDU "addu"
#define __UA_t0 "$8"
#define __UA_t1 "$9"
#endif /* CONFIG_32BIT */
#ifdef CONFIG_64BIT
extern u64 __ua_limit;
#define __UA_LIMIT __ua_limit
#define __UA_ADDR ".dword"
#define __UA_LA "dla"
#define __UA_ADDU "daddu"
#define __UA_t0 "$12"
#define __UA_t1 "$13"
#endif /* CONFIG_64BIT */
/*
* USER_DS is a bitmask that has the bits set that may not be set in a valid
* userspace address. Note that we limit 32-bit userspace to 0x7fff8000 but
* the arithmetic we're doing only works if the limit is a power of two, so
* we use 0x80000000 here on 32-bit kernels. If a process passes an invalid
* address in this range it's the process's problem, not ours :-)
*/
#ifdef CONFIG_KVM_GUEST
#define KERNEL_DS ((mm_segment_t) { 0x80000000UL })
#define USER_DS ((mm_segment_t) { 0xC0000000UL })
#else
#define KERNEL_DS ((mm_segment_t) { 0UL })
#define USER_DS ((mm_segment_t) { __UA_LIMIT })
#endif
#define VERIFY_READ 0
#define VERIFY_WRITE 1
#define get_ds() (KERNEL_DS)
#define get_fs() (current_thread_info()->addr_limit)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
#define segment_eq(a, b) ((a).seg == (b).seg)
/*
* eva_kernel_access() - determine whether kernel memory access on an EVA system