Linux kernel mirror (for testing)
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linux
1#ifndef _H8300_SYSTEM_H
2#define _H8300_SYSTEM_H
3
4#include <linux/config.h> /* get configuration macros */
5#include <linux/linkage.h>
6
7#define prepare_to_switch() do { } while(0)
8
9/*
10 * switch_to(n) should switch tasks to task ptr, first checking that
11 * ptr isn't the current task, in which case it does nothing. This
12 * also clears the TS-flag if the task we switched to has used the
13 * math co-processor latest.
14 */
15/*
16 * switch_to() saves the extra registers, that are not saved
17 * automatically by SAVE_SWITCH_STACK in resume(), ie. d0-d5 and
18 * a0-a1. Some of these are used by schedule() and its predecessors
19 * and so we might get see unexpected behaviors when a task returns
20 * with unexpected register values.
21 *
22 * syscall stores these registers itself and none of them are used
23 * by syscall after the function in the syscall has been called.
24 *
25 * Beware that resume now expects *next to be in d1 and the offset of
26 * tss to be in a1. This saves a few instructions as we no longer have
27 * to push them onto the stack and read them back right after.
28 *
29 * 02/17/96 - Jes Sorensen (jds@kom.auc.dk)
30 *
31 * Changed 96/09/19 by Andreas Schwab
32 * pass prev in a0, next in a1, offset of tss in d1, and whether
33 * the mm structures are shared in d2 (to avoid atc flushing).
34 *
35 * H8/300 Porting 2002/09/04 Yoshinori Sato
36 */
37
38asmlinkage void resume(void);
39#define switch_to(prev,next,last) { \
40 void *_last; \
41 __asm__ __volatile__( \
42 "mov.l %1, er0\n\t" \
43 "mov.l %2, er1\n\t" \
44 "mov.l %3, er2\n\t" \
45 "jsr @_resume\n\t" \
46 "mov.l er2,%0\n\t" \
47 : "=r" (_last) \
48 : "r" (&(prev->thread)), \
49 "r" (&(next->thread)), \
50 "g" (prev) \
51 : "cc", "er0", "er1", "er2", "er3"); \
52 (last) = _last; \
53}
54
55#define __sti() asm volatile ("andc #0x7f,ccr")
56#define __cli() asm volatile ("orc #0x80,ccr")
57
58#define __save_flags(x) \
59 asm volatile ("stc ccr,%w0":"=r" (x))
60
61#define __restore_flags(x) \
62 asm volatile ("ldc %w0,ccr": :"r" (x))
63
64#define irqs_disabled() \
65({ \
66 unsigned char flags; \
67 __save_flags(flags); \
68 ((flags & 0x80) == 0x80); \
69})
70
71#define iret() __asm__ __volatile__ ("rte": : :"memory", "sp", "cc")
72
73/* For spinlocks etc */
74#define local_irq_disable() __cli()
75#define local_irq_enable() __sti()
76#define local_irq_save(x) ({ __save_flags(x); local_irq_disable(); })
77#define local_irq_restore(x) __restore_flags(x)
78#define local_save_flags(x) __save_flags(x)
79
80/*
81 * Force strict CPU ordering.
82 * Not really required on H8...
83 */
84#define nop() asm volatile ("nop"::)
85#define mb() asm volatile ("" : : :"memory")
86#define rmb() asm volatile ("" : : :"memory")
87#define wmb() asm volatile ("" : : :"memory")
88#define set_rmb(var, value) do { xchg(&var, value); } while (0)
89#define set_mb(var, value) set_rmb(var, value)
90#define set_wmb(var, value) do { var = value; wmb(); } while (0)
91
92#ifdef CONFIG_SMP
93#define smp_mb() mb()
94#define smp_rmb() rmb()
95#define smp_wmb() wmb()
96#define smp_read_barrier_depends() read_barrier_depends()
97#else
98#define smp_mb() barrier()
99#define smp_rmb() barrier()
100#define smp_wmb() barrier()
101#define smp_read_barrier_depends() do { } while(0)
102#endif
103
104#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
105#define tas(ptr) (xchg((ptr),1))
106
107struct __xchg_dummy { unsigned long a[100]; };
108#define __xg(x) ((volatile struct __xchg_dummy *)(x))
109
110static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
111{
112 unsigned long tmp, flags;
113
114 local_irq_save(flags);
115
116 switch (size) {
117 case 1:
118 __asm__ __volatile__
119 ("mov.b %2,%0\n\t"
120 "mov.b %1,%2"
121 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
122 break;
123 case 2:
124 __asm__ __volatile__
125 ("mov.w %2,%0\n\t"
126 "mov.w %1,%2"
127 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
128 break;
129 case 4:
130 __asm__ __volatile__
131 ("mov.l %2,%0\n\t"
132 "mov.l %1,%2"
133 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
134 break;
135 default:
136 tmp = 0;
137 }
138 local_irq_restore(flags);
139 return tmp;
140}
141
142#define HARD_RESET_NOW() ({ \
143 local_irq_disable(); \
144 asm("jmp @@0"); \
145})
146
147#define arch_align_stack(x) (x)
148
149#endif /* _H8300_SYSTEM_H */