1 /*
2 * include/asm-microblaze/system.h -- Low-level interrupt/thread ops
3 *
4 * Copyright (C) 2003 John Williams (jwilliams@itee.uq.edu.au)
5 * based upon microblaze version
6 * Copyright (C) 2001 NEC Corporation
7 * Copyright (C) 2001 Miles Bader <miles@gnu.org>
8 *
9 * This file is subject to the terms and conditions of the GNU General
10 * Public License. See the file COPYING in the main directory of this
11 * archive for more details.
12 *
13 * Written by Miles Bader <miles@gnu.org>
14 * Microblaze port by John Williams
15 * Microblaze port by John Williams
16 */
17
18 #ifndef __MICROBLAZE_SYSTEM_H__
19 #define __MICROBLAZE_SYSTEM_H__
20
21 #if 0
22 #include <linux/linkage.h>
23 #endif
24 #include <asm/ptrace.h>
25
26 #define prepare_to_switch() do { } while (0)
27
28 /*
29 * switch_to(n) should switch tasks to task ptr, first checking that
30 * ptr isn't the current task, in which case it does nothing.
31 */
32 struct thread_struct;
33 extern void *switch_thread (struct thread_struct *last,
34 struct thread_struct *next);
35 #define switch_to(prev,next,last) do { \
36 if (prev != next) { \
37 (last) = switch_thread (&prev->thread, &next->thread); \
38 } \
39 } while (0)
40
41
42 /* Enable/disable interrupts. */
43 #define __sti() \
44 { \
45 register unsigned tmp; \
46 __asm__ __volatile__ (" \
47 mfs %0, rmsr; \
48 ori %0, %0, 2; \
49 mts rmsr, %0" \
50 : "=r" (tmp) \
51 : \
52 : "memory"); \
53 }
54
55 #define __cli() \
56 { \
57 register unsigned tmp; \
58 __asm__ __volatile__ (" \
59 mfs %0, rmsr; \
60 andi %0, %0, ~2; \
61 mts rmsr, %0" \
62 : "=r" (tmp) \
63 : \
64 : "memory"); \
65 }
66
67 #define __save_flags(flags) \
68 __asm__ __volatile__ ("mfs %0, rmsr" : "=r" (flags))
69 #define __restore_flags(flags) \
70 __asm__ __volatile__ ("mts rmsr, %0" :: "r" (flags))
71
72 #define __save_flags_cli(flags) \
73 { \
74 register unsigned tmp; \
75 __asm__ __volatile__ (" \
76 mfs %0, rmsr; \
77 andi %1, %0, ~2; \
78 mts rmsr, %1;" \
79 : "=r" (flags), "=r" (tmp) \
80 : \
81 : "memory"); \
82 }
83
84 #define __save_flags_sti(flags) \
85 { \
86 register unsigned tmp; \
87 __asm__ __volatile__ (" \
88 mfs %0, rmsr; \
89 ori %1, %0, 2; \
90 mts rmsr, %1;" \
91 : "=r" (flags) ,"=r" (tmp) \
92 : \
93 : "memory"); \
94 }
95
96 /* For spinlocks etc */
97 #define local_irq_save(flags) __save_flags_cli (flags)
98 #define local_irq_set(flags) __save_flags_sti (flags)
99 #define local_irq_restore(flags) __restore_flags (flags)
100 #define local_irq_disable() __cli ()
101 #define local_irq_enable() __sti ()
102
103 #define cli() __cli ()
104 #define sti() __sti ()
105 #define save_flags(flags) __save_flags (flags)
106 #define restore_flags(flags) __restore_flags (flags)
107 #define save_flags_cli(flags) __save_flags_cli (flags)
108
109 /*
110 * Force strict CPU ordering.
111 * Not really required on microblaze...
112 */
113 #define nop() __asm__ __volatile__ ("nop")
114 #define mb() __asm__ __volatile__ ("nop" ::: "memory")
115 #define rmb() mb ()
116 #define wmb() mb ()
117 #define set_mb(var, value) do { var = value; mb(); } while (0)
118 #define set_wmb(var, value) do { var = value; wmb (); } while (0)
119
120 #ifdef CONFIG_SMP
121 #define smp_mb() mb ()
122 #define smp_rmb() rmb ()
123 #define smp_wmb() wmb ()
124 #else
125 #define smp_mb() barrier ()
126 #define smp_rmb() barrier ()
127 #define smp_wmb() barrier ()
128 #endif
129
130 #define xchg(ptr, with) \
131 ((__typeof__ (*(ptr)))__xchg ((unsigned long)(with), (ptr), sizeof (*(ptr))))
132 #define tas(ptr) (xchg ((ptr), 1))
133
__xchg(unsigned long with,__volatile__ void * ptr,int size)134 static inline unsigned long __xchg(unsigned long with,
135 __volatile__ void *ptr, int size)
136 {
137 unsigned long tmp, flags;
138
139 save_flags_cli (flags);
140
141 switch (size) {
142 case 1:
143 tmp = *(unsigned char *)ptr;
144 *(unsigned char *)ptr = with;
145 break;
146 case 2:
147 tmp = *(unsigned short *)ptr;
148 *(unsigned short *)ptr = with;
149 break;
150 case 4:
151 tmp = *(unsigned long *)ptr;
152 *(unsigned long *)ptr = with;
153 break;
154 }
155
156 restore_flags (flags);
157
158 return tmp;
159 }
160
161 #endif /* __MICROBLAZE_SYSTEM_H__ */
162