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 MMU_SECTION_SIZE (1 * 1024 * 1024)
27
28 #define prepare_to_switch() do { } while (0)
29
30 /*
31 * switch_to(n) should switch tasks to task ptr, first checking that
32 * ptr isn't the current task, in which case it does nothing.
33 */
34 struct thread_struct;
35 extern void *switch_thread (struct thread_struct *last,
36 struct thread_struct *next);
37 #define switch_to(prev,next,last) do { \
38 if (prev != next) { \
39 (last) = switch_thread (&prev->thread, &next->thread); \
40 } \
41 } while (0)
42
43 /* Enable/disable interrupts. */
44 #define __sti() \
45 { \
46 register unsigned tmp; \
47 __asm__ __volatile__ (" \
48 mfs %0, rmsr; \
49 ori %0, %0, 2; \
50 mts rmsr, %0" \
51 : "=r" (tmp) \
52 : \
53 : "memory"); \
54 }
55
56 #define __cli() \
57 { \
58 register unsigned tmp; \
59 __asm__ __volatile__ (" \
60 mfs %0, rmsr; \
61 andi %0, %0, ~2; \
62 mts rmsr, %0" \
63 : "=r" (tmp) \
64 : \
65 : "memory"); \
66 }
67
68 #define __save_flags(flags) \
69 __asm__ __volatile__ ("mfs %0, rmsr" : "=r" (flags))
70 #define __restore_flags(flags) \
71 __asm__ __volatile__ ("mts rmsr, %0" :: "r" (flags))
72
73 #define __save_flags_cli(flags) \
74 { \
75 register unsigned tmp; \
76 __asm__ __volatile__ (" \
77 mfs %0, rmsr; \
78 andi %1, %0, ~2; \
79 mts rmsr, %1;" \
80 : "=r" (flags), "=r" (tmp) \
81 : \
82 : "memory"); \
83 }
84
85 #define __save_flags_sti(flags) \
86 { \
87 register unsigned tmp; \
88 __asm__ __volatile__ (" \
89 mfs %0, rmsr; \
90 ori %1, %0, 2; \
91 mts rmsr, %1;" \
92 : "=r" (flags) ,"=r" (tmp) \
93 : \
94 : "memory"); \
95 }
96
97 /* For spinlocks etc */
98 #define local_irq_save(flags) __save_flags_cli (flags)
99 #define local_irq_set(flags) __save_flags_sti (flags)
100 #define local_irq_restore(flags) __restore_flags (flags)
101 #define local_irq_disable() __cli ()
102 #define local_irq_enable() __sti ()
103
104 #define cli() __cli ()
105 #define sti() __sti ()
106 #define save_flags(flags) __save_flags (flags)
107 #define restore_flags(flags) __restore_flags (flags)
108 #define save_flags_cli(flags) __save_flags_cli (flags)
109
110 /*
111 * Force strict CPU ordering.
112 * Not really required on microblaze...
113 */
114 #define nop() __asm__ __volatile__ ("nop")
115 #define mb() __asm__ __volatile__ ("nop" ::: "memory")
116 #define rmb() mb ()
117 #define wmb() mb ()
118 #define set_mb(var, value) do { var = value; mb(); } while (0)
119 #define set_wmb(var, value) do { var = value; wmb (); } while (0)
120
121 #ifdef CONFIG_SMP
122 #define smp_mb() mb ()
123 #define smp_rmb() rmb ()
124 #define smp_wmb() wmb ()
125 #else
126 #define smp_mb() barrier ()
127 #define smp_rmb() barrier ()
128 #define smp_wmb() barrier ()
129 #endif
130
131 #define xchg(ptr, with) \
132 ((__typeof__ (*(ptr)))__xchg ((unsigned long)(with), (ptr), sizeof (*(ptr))))
133 #define tas(ptr) (xchg ((ptr), 1))
134
__xchg(unsigned long with,__volatile__ void * ptr,int size)135 static inline unsigned long __xchg(unsigned long with,
136 __volatile__ void *ptr, int size)
137 {
138 unsigned long tmp, flags;
139
140 save_flags_cli (flags);
141
142 switch (size) {
143 case 1:
144 tmp = *(unsigned char *)ptr;
145 *(unsigned char *)ptr = with;
146 break;
147 case 2:
148 tmp = *(unsigned short *)ptr;
149 *(unsigned short *)ptr = with;
150 break;
151 case 4:
152 tmp = *(unsigned long *)ptr;
153 *(unsigned long *)ptr = with;
154 break;
155 }
156
157 restore_flags (flags);
158
159 return tmp;
160 }
161
162 #endif /* __MICROBLAZE_SYSTEM_H__ */
163