1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_SH_SEGMENT_H
3 #define __ASM_SH_SEGMENT_H
4 
5 #ifndef __ASSEMBLY__
6 
7 typedef struct {
8 	unsigned long seg;
9 } mm_segment_t;
10 
11 #define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })
12 
13 /*
14  * The fs value determines whether argument validity checking should be
15  * performed or not.  If get_fs() == USER_DS, checking is performed, with
16  * get_fs() == KERNEL_DS, checking is bypassed.
17  *
18  * For historical reasons, these macros are grossly misnamed.
19  */
20 #define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFFUL)
21 #ifdef CONFIG_MMU
22 #define USER_DS		MAKE_MM_SEG(PAGE_OFFSET)
23 #else
24 #define USER_DS		KERNEL_DS
25 #endif
26 
27 #define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
28 
29 #define get_fs()	(current_thread_info()->addr_limit)
30 #define set_fs(x)	(current_thread_info()->addr_limit = (x))
31 
32 #endif /* __ASSEMBLY__ */
33 #endif /* __ASM_SH_SEGMENT_H */
34