Linux Kernel  3.7.1
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segment.h
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1 #ifndef _M68K_SEGMENT_H
2 #define _M68K_SEGMENT_H
3 
4 /* define constants */
5 /* Address spaces (FC0-FC2) */
6 #define USER_DATA (1)
7 #ifndef __USER_DS
8 #define __USER_DS (USER_DATA)
9 #endif
10 #define USER_PROGRAM (2)
11 #define SUPER_DATA (5)
12 #ifndef __KERNEL_DS
13 #define __KERNEL_DS (SUPER_DATA)
14 #endif
15 #define SUPER_PROGRAM (6)
16 #define CPU_SPACE (7)
17 
18 #ifndef __ASSEMBLY__
19 
20 typedef struct {
21  unsigned long seg;
22 } mm_segment_t;
23 
24 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
25 
26 #ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
27 /*
28  * Get/set the SFC/DFC registers for MOVES instructions
29  */
30 #define USER_DS MAKE_MM_SEG(__USER_DS)
31 #define KERNEL_DS MAKE_MM_SEG(__KERNEL_DS)
32 
33 static inline mm_segment_t get_fs(void)
34 {
35  mm_segment_t _v;
36  __asm__ ("movec %/dfc,%0":"=r" (_v.seg):);
37  return _v;
38 }
39 
40 static inline void set_fs(mm_segment_t val)
41 {
42  __asm__ __volatile__ ("movec %0,%/sfc\n\t"
43  "movec %0,%/dfc\n\t"
44  : /* no outputs */ : "r" (val.seg) : "memory");
45 }
46 
47 static inline mm_segment_t get_ds(void)
48 {
49  /* return the supervisor data space code */
50  return KERNEL_DS;
51 }
52 
53 #else
54 #define USER_DS MAKE_MM_SEG(TASK_SIZE)
55 #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
56 #define get_ds() (KERNEL_DS)
57 #define get_fs() (current_thread_info()->addr_limit)
58 #define set_fs(x) (current_thread_info()->addr_limit = (x))
59 #endif
60 
61 #define segment_eq(a,b) ((a).seg == (b).seg)
62 
63 #endif /* __ASSEMBLY__ */
64 
65 #endif /* _M68K_SEGMENT_H */