Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
segment.h
Go to the documentation of this file.
1 #ifndef __ASM_SH_SEGMENT_H
2 #define __ASM_SH_SEGMENT_H
3 
4 #ifndef __ASSEMBLY__
5 
6 typedef struct {
7  unsigned long seg;
9 
10 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
11 
12 /*
13  * The fs value determines whether argument validity checking should be
14  * performed or not. If get_fs() == USER_DS, checking is performed, with
15  * get_fs() == KERNEL_DS, checking is bypassed.
16  *
17  * For historical reasons, these macros are grossly misnamed.
18  */
19 #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFUL)
20 #ifdef CONFIG_MMU
21 #define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
22 #else
23 #define USER_DS KERNEL_DS
24 #endif
25 
26 #define segment_eq(a,b) ((a).seg == (b).seg)
27 
28 #define get_ds() (KERNEL_DS)
29 
30 #define get_fs() (current_thread_info()->addr_limit)
31 #define set_fs(x) (current_thread_info()->addr_limit = (x))
32 
33 #endif /* __ASSEMBLY__ */
34 #endif /* __ASM_SH_SEGMENT_H */