1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
#ifndef _M68K_SYSTEM_H
#define _M68K_SYSTEM_H
#include <linux/config.h> /* get configuration macros */
#include <linux/linkage.h>
#include <asm/segment.h>
extern inline unsigned long rdusp(void) {
unsigned long usp;
__asm__ __volatile__("movec %/usp,%0"
: "=d" (usp));
return usp;
}
extern inline void wrusp(unsigned long usp) {
__asm__ __volatile__("movec %0,%/usp"
:
: "d" (usp));
}
/*
* switch_to(n) should switch tasks to task ptr, first checking that
* ptr isn't the current task, in which case it does nothing. This
* also clears the TS-flag if the task we switched to has used the
* math co-processor latest.
*/
/*
* switch_to() saves the extra registers, that are not saved
* automatically by SAVE_SWITCH_STACK in resume(), ie. d0-d5 and
* a0-a1. Some of these are used by schedule() and its predecessors
* and so we might get see unexpected behaviors when a task returns
* with unexpected register values.
*
* syscall stores these registers itself and none of them are used
* by syscall after the function in the syscall has been called.
*
* Beware that resume now expects *next to be in d1 and the offset of
* tss to be in a1. This saves a few instructions as we no longer have
* to push them onto the stack and read them back right after.
*
* 02/17/96 - Jes Sorensen (jds@kom.auc.dk)
*
* Changed 96/09/19 by Andreas Schwab
* pass prev in a0, next in a1, offset of tss in d1, and whether
* the mm structures are shared in d2 (to avoid atc flushing).
*/
asmlinkage void resume(void);
#define switch_to(prev,next) { \
register void *_prev __asm__ ("a0") = (prev); \
register void *_next __asm__ ("a1") = (next); \
register int _tssoff __asm__ ("d1") = (int)&((struct task_struct *)0)->tss; \
register char _shared __asm__ ("d2") = ((prev)->mm == (next)->mm); \
__asm__ __volatile__("jbsr " SYMBOL_NAME_STR(resume) "\n\t" \
: : "a" (_prev), "a" (_next), "d" (_tssoff), \
"d" (_shared) \
: "d0", "d1", "d2", "d3", "d4", "d5", "a0", "a1"); \
}
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
#define tas(ptr) (xchg((ptr),1))
struct __xchg_dummy { unsigned long a[100]; };
#define __xg(x) ((volatile struct __xchg_dummy *)(x))
#if defined(CONFIG_ATARI) && !defined(CONFIG_AMIGA) && !defined(CONFIG_MAC)
/* block out HSYNC on the atari */
#define __sti() __asm__ __volatile__ ("andiw #0xfbff,%/sr": : : "memory")
#else /* portable version */
#define __sti() __asm__ __volatile__ ("andiw #0xf8ff,%/sr": : : "memory")
#endif /* machine compilation types */
#define __cli() __asm__ __volatile__ ("oriw #0x0700,%/sr": : : "memory")
#define nop() __asm__ __volatile__ ("nop"::)
#define mb() __asm__ __volatile__ ("" : : :"memory")
#define __save_flags(x) \
__asm__ __volatile__("movew %/sr,%0":"=d" (x) : /* no input */ :"memory")
#define __restore_flags(x) \
__asm__ __volatile__("movew %0,%/sr": /* no outputs */ :"d" (x) : "memory")
#define cli() __cli()
#define sti() __sti()
#define save_flags(x) __save_flags(x)
#define restore_flags(x) __restore_flags(x)
#define save_and_cli(flags) do { save_flags(flags); cli(); } while(0)
#ifndef CONFIG_RMW_INSNS
static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
{
unsigned long tmp, flags;
save_flags(flags);
cli();
switch (size) {
case 1:
__asm__ __volatile__
("moveb %2,%0\n\t"
"moveb %1,%2"
: "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 2:
__asm__ __volatile__
("movew %2,%0\n\t"
"movew %1,%2"
: "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 4:
__asm__ __volatile__
("movel %2,%0\n\t"
"movel %1,%2"
: "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
}
restore_flags(flags);
return tmp;
}
#else
static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
{
switch (size) {
case 1:
__asm__ __volatile__
("moveb %2,%0\n\t"
"1:\n\t"
"casb %0,%1,%2\n\t"
"jne 1b"
: "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 2:
__asm__ __volatile__
("movew %2,%0\n\t"
"1:\n\t"
"casw %0,%1,%2\n\t"
"jne 1b"
: "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 4:
__asm__ __volatile__
("movel %2,%0\n\t"
"1:\n\t"
"casl %0,%1,%2\n\t"
"jne 1b"
: "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
}
return x;
}
#endif
#endif /* _M68K_SYSTEM_H */
|
