File: /usr/src/linux/include/asm-cris/system.h
1 /* $Id: system.h,v 1.4 2001/03/20 19:46:00 bjornw Exp $ */
2
3 #ifndef __ASM_CRIS_SYSTEM_H
4 #define __ASM_CRIS_SYSTEM_H
5
6 #include <linux/config.h>
7
8 #include <asm/segment.h>
9
10 /* the switch_to macro calls resume, an asm function in entry.S which does the actual
11 * task switching.
12 */
13
14 extern struct task_struct *resume(struct task_struct *prev, struct task_struct *next, int);
15 #define prepare_to_switch() do { } while(0)
16 #define switch_to(prev,next,last) last = resume(prev,next, \
17 (int)&((struct task_struct *)0)->thread)
18
19 /* read/write the user-mode stackpointer */
20
21 extern inline unsigned long rdusp(void) {
22 unsigned long usp;
23 __asm__ __volatile__("move usp,%0" : "=rm" (usp));
24 return usp;
25 }
26
27 #define wrusp(usp) \
28 __asm__ __volatile__("move %0,usp" : /* no outputs */ : "rm" (usp))
29
30 /* read the current stackpointer */
31
32 extern inline unsigned long rdsp(void) {
33 unsigned long sp;
34 __asm__ __volatile__("move.d sp,%0" : "=rm" (sp));
35 return sp;
36 }
37
38 static inline unsigned long _get_base(char * addr)
39 {
40 return 0;
41 }
42
43 #define nop() __asm__ __volatile__ ("nop");
44
45 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
46 #define tas(ptr) (xchg((ptr),1))
47
48 struct __xchg_dummy { unsigned long a[100]; };
49 #define __xg(x) ((struct __xchg_dummy *)(x))
50
51 #if 0
52 /* use these and an oscilloscope to see the fraction of time we're running with IRQ's disabled */
53 /* it assumes the LED's are on port 0x90000000 of course. */
54 #define sti() __asm__ __volatile__ ( "ei\n\tpush r0\n\tmoveq 0,r0\n\tmove.d r0,[0x90000000]\n\tpop r0" );
55 #define cli() __asm__ __volatile__ ( "di\n\tpush r0\n\tmove.d 0x40000,r0\n\tmove.d r0,[0x90000000]\n\tpop r0");
56 #define save_flags(x) __asm__ __volatile__ ("move ccr,%0" : "=rm" (x) : : "memory");
57 #define restore_flags(x) __asm__ __volatile__ ("move %0,ccr\n\tbtstq 5,%0\n\tbpl 1f\n\tnop\n\tpush r0\n\tmoveq 0,r0\n\tmove.d r0,[0x90000000]\n\tpop r0\n1:\n" : : "r" (x) : "memory");
58 #else
59 #define __cli() __asm__ __volatile__ ( "di");
60 #define __sti() __asm__ __volatile__ ( "ei" );
61 #define __save_flags(x) __asm__ __volatile__ ("move ccr,%0" : "=rm" (x) : : "memory");
62 #define __restore_flags(x) __asm__ __volatile__ ("move %0,ccr" : : "rm" (x) : "memory");
63
64 /* For spinlocks etc */
65 #define local_irq_save(x) __asm__ __volatile__ ("move ccr,%0\n\tdi" : "=rm" (x) : : "memory");
66 #define local_irq_restore(x) restore_flags(x)
67
68 #define local_irq_disable() cli()
69 #define local_irq_enable() sti()
70
71 #endif
72
73 #define cli() __cli()
74 #define sti() __sti()
75 #define save_flags(x) __save_flags(x)
76 #define restore_flags(x) __restore_flags(x)
77 #define save_and_cli(x) do { __save_flags(x); cli(); } while(0)
78
79 static inline unsigned long __xchg(unsigned long x, void * ptr, int size)
80 {
81 /* since Etrax doesn't have any atomic xchg instructions, we need to disable
82 irq's (if enabled) and do it with move.d's */
83 #if 0
84 unsigned int flags;
85 save_flags(flags); /* save flags, including irq enable bit */
86 cli(); /* shut off irq's */
87 switch (size) {
88 case 1:
89 __asm__ __volatile__ (
90 "move.b %0,r0\n\t"
91 "move.b %1,%0\n\t"
92 "move.b r0,%1\n\t"
93 : "=r" (x)
94 : "m" (*__xg(ptr)), "r" (x)
95 : "memory","r0");
96 break;
97 case 2:
98 __asm__ __volatile__ (
99 "move.w %0,r0\n\t"
100 "move.w %1,%0\n\t"
101 "move.w r0,%1\n\t"
102 : "=r" (x)
103 : "m" (*__xg(ptr)), "r" (x)
104 : "memory","r0");
105 break;
106 case 4:
107 __asm__ __volatile__ (
108 "move.d %0,r0\n\t"
109 "move.d %1,%0\n\t"
110 "move.d r0,%1\n\t"
111 : "=r" (x)
112 : "m" (*__xg(ptr)), "r" (x)
113 : "memory","r0");
114 break;
115 }
116 restore_flags(flags); /* restore irq enable bit */
117 return x;
118 #else
119 unsigned long flags,temp;
120 save_flags(flags); /* save flags, including irq enable bit */
121 cli(); /* shut off irq's */
122 switch (size) {
123 case 1:
124 *((unsigned char *)&temp) = x;
125 x = *(unsigned char *)ptr;
126 *(unsigned char *)ptr = *((unsigned char *)&temp);
127 break;
128 case 2:
129 *((unsigned short *)&temp) = x;
130 x = *(unsigned short *)ptr;
131 *(unsigned short *)ptr = *((unsigned short *)&temp);
132 break;
133 case 4:
134 temp = x;
135 x = *(unsigned long *)ptr;
136 *(unsigned long *)ptr = temp;
137 break;
138 }
139 restore_flags(flags); /* restore irq enable bit */
140 return x;
141 #endif
142 }
143
144 #define mb() __asm__ __volatile__ ("" : : : "memory")
145 #define rmb() mb()
146 #define wmb() mb()
147
148 #ifdef CONFIG_SMP
149 #define smp_mb() mb()
150 #define smp_rmb() rmb()
151 #define smp_wmb() wmb()
152 #else
153 #define smp_mb() barrier()
154 #define smp_rmb() barrier()
155 #define smp_wmb() barrier()
156 #endif
157
158 #define iret()
159
160 /*
161 * disable hlt during certain critical i/o operations
162 */
163 #define HAVE_DISABLE_HLT
164 void disable_hlt(void);
165 void enable_hlt(void);
166
167 #endif
168