1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _M68K_SEGMENT_H
3 #define _M68K_SEGMENT_H
4 
5 /* define constants */
6 /* Address spaces (FC0-FC2) */
7 #define USER_DATA     (1)
8 #ifndef __USER_DS
9 #define __USER_DS     (USER_DATA)
10 #endif
11 #define USER_PROGRAM  (2)
12 #define SUPER_DATA    (5)
13 #ifndef __KERNEL_DS
14 #define __KERNEL_DS   (SUPER_DATA)
15 #endif
16 #define SUPER_PROGRAM (6)
17 #define CPU_SPACE     (7)
18 
19 #ifndef __ASSEMBLY__
20 
21 typedef struct {
22 	unsigned long seg;
23 } mm_segment_t;
24 
25 #define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })
26 
27 #ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
28 /*
29  * Get/set the SFC/DFC registers for MOVES instructions
30  */
31 #define USER_DS		MAKE_MM_SEG(__USER_DS)
32 #define KERNEL_DS	MAKE_MM_SEG(__KERNEL_DS)
33 
get_fs(void)34 static inline mm_segment_t get_fs(void)
35 {
36 	mm_segment_t _v;
37 	__asm__ ("movec %/dfc,%0":"=r" (_v.seg):);
38 	return _v;
39 }
40 
set_fs(mm_segment_t val)41 static inline void set_fs(mm_segment_t val)
42 {
43 	__asm__ __volatile__ ("movec %0,%/sfc\n\t"
44 			      "movec %0,%/dfc\n\t"
45 			      : /* no outputs */ : "r" (val.seg) : "memory");
46 }
47 
48 #else
49 #define USER_DS		MAKE_MM_SEG(TASK_SIZE)
50 #define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)
51 #define get_fs()	(current_thread_info()->addr_limit)
52 #define set_fs(x)	(current_thread_info()->addr_limit = (x))
53 #endif
54 
55 #define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
56 
57 #endif /* __ASSEMBLY__ */
58 
59 #endif /* _M68K_SEGMENT_H */
60