1 #ifndef _H8300_SYSTEM_H
2 #define _H8300_SYSTEM_H
4 #include <linux/config.h> /* get configuration macros */
5 #include <linux/kernel.h>
6 #include <linux/linkage.h>
8 #define prepare_to_switch() do { } while(0)
11 * switch_to(n) should switch tasks to task ptr, first checking that
12 * ptr isn't the current task, in which case it does nothing. This
13 * also clears the TS-flag if the task we switched to has used the
14 * math co-processor latest.
17 * switch_to() saves the extra registers, that are not saved
18 * automatically by SAVE_SWITCH_STACK in resume(), ie. d0-d5 and
19 * a0-a1. Some of these are used by schedule() and its predecessors
20 * and so we might get see unexpected behaviors when a task returns
21 * with unexpected register values.
23 * syscall stores these registers itself and none of them are used
24 * by syscall after the function in the syscall has been called.
26 * Beware that resume now expects *next to be in d1 and the offset of
27 * tss to be in a1. This saves a few instructions as we no longer have
28 * to push them onto the stack and read them back right after.
30 * 02/17/96 - Jes Sorensen (jds@kom.auc.dk)
32 * Changed 96/09/19 by Andreas Schwab
33 * pass prev in a0, next in a1, offset of tss in d1, and whether
34 * the mm structures are shared in d2 (to avoid atc flushing).
36 * H8/300 Porting 2002/09/04 Yoshinori Sato
38 asmlinkage void resume(void);
39 #define switch_to(prev,next,last) { \
41 __asm__ __volatile__( \
46 : "r" (&(prev->thread)), \
47 "r" (&(next->thread)) \
48 : "cc", "er0", "er1", "er2", "er3"); \
52 #if defined(__H8300H__)
53 #define __sti() asm volatile ("andc #0x7f,ccr")
54 #define __cli() asm volatile ("orc #0x80,ccr")
56 #define __save_flags(x) \
57 asm volatile ("sub.l er0,er0\n\tstc ccr,r0l\n\tmov.l er0,%0":"=r" (x) : : "er0")
59 #define __restore_flags(x) \
60 asm volatile ("mov.l %0,er0\n\tldc r0l,ccr": :"r" (x) : "er0")
62 #if defined(__H8300S__)
63 #define __sti() asm volatile ("andc #0xf8,exr")
64 #define __cli() asm volatile ("orc #0x07,exr")
66 #define __save_flags(x) \
67 asm volatile ("sub.l er0,er0\n\tstc exr,r0l\n\tmov.l er0,%0":"=r" (x) : : "er0")
69 #define __restore_flags(x) \
70 asm volatile ("mov.l %0,er0\n\tldc r0l,exr": :"r" (x) : "er0")
73 #define irqs_disabled() \
75 unsigned long flags; \
76 __save_flags(flags); \
77 ((flags & 0x80) == 0x80); \
80 #define iret() __asm__ __volatile__ ("rte": : :"memory", "sp", "cc")
82 /* For spinlocks etc */
83 #define local_irq_disable() asm volatile ("orc #0x80,ccr")
84 #define local_irq_enable() asm volatile ("andc #0x7f,ccr")
85 #define local_irq_save(x) ({ __save_flags(x); local_irq_disable(); })
86 #define local_irq_restore(x) __restore_flags(x)
87 #define local_save_flags(x) __save_flags(x)
90 * Force strict CPU ordering.
91 * Not really required on m68k...
93 #define nop() asm volatile ("nop"::)
94 #define mb() asm volatile ("" : : :"memory")
95 #define rmb() asm volatile ("" : : :"memory")
96 #define wmb() asm volatile ("" : : :"memory")
97 #define set_rmb(var, value) do { xchg(&var, value); } while (0)
98 #define set_mb(var, value) set_rmb(var, value)
99 #define set_wmb(var, value) do { var = value; wmb(); } while (0)
102 #define smp_mb() mb()
103 #define smp_rmb() rmb()
104 #define smp_wmb() wmb()
105 #define smp_read_barrier_depends() read_barrier_depends()
107 #define smp_mb() barrier()
108 #define smp_rmb() barrier()
109 #define smp_wmb() barrier()
110 #define smp_read_barrier_depends() do { } while(0)
113 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
114 #define tas(ptr) (xchg((ptr),1))
116 struct __xchg_dummy { unsigned long a[100]; };
117 #define __xg(x) ((volatile struct __xchg_dummy *)(x))
119 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
121 unsigned long tmp, flags;
123 local_irq_save(flags);
130 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "er0","memory");
136 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
142 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
147 local_irq_restore(flags);
151 #define HARD_RESET_NOW() ({ \
152 local_irq_disable(); \
156 #endif /* _H8300_SYSTEM_H */