summaryrefslogtreecommitdiffstats
path: root/include/asm-h8300/system.h
blob: 8e81cf665e75ea3406b2d4a79f7a002671aa52f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
#ifndef _H8300_SYSTEM_H
#define _H8300_SYSTEM_H

#include <linux/config.h> /* get configuration macros */
#include <linux/linkage.h>

/*
 * switch_to(n) should switch tasks to task ptr, first checking that
 * ptr isn't the current task, in which case it does nothing.  This
 * also clears the TS-flag if the task we switched to has used the
 * math co-processor latest.
 */
/*
 * switch_to() saves the extra registers, that are not saved
 * automatically by SAVE_SWITCH_STACK in resume(), ie. d0-d5 and
 * a0-a1. Some of these are used by schedule() and its predecessors
 * and so we might get see unexpected behaviors when a task returns
 * with unexpected register values.
 *
 * syscall stores these registers itself and none of them are used
 * by syscall after the function in the syscall has been called.
 *
 * Beware that resume now expects *next to be in d1 and the offset of
 * tss to be in a1. This saves a few instructions as we no longer have
 * to push them onto the stack and read them back right after.
 *
 * 02/17/96 - Jes Sorensen (jds@kom.auc.dk)
 *
 * Changed 96/09/19 by Andreas Schwab
 * pass prev in a0, next in a1, offset of tss in d1, and whether
 * the mm structures are shared in d2 (to avoid atc flushing).
 *
 * H8/300 Porting 2002/09/04 Yoshinori Sato
 */

asmlinkage void resume(void);
#define switch_to(prev,next,last) {                         \
  void *_last;						    \
  __asm__ __volatile__(					    \
  			"mov.l	%1, er0\n\t"		    \
			"mov.l	%2, er1\n\t"		    \
                        "mov.l  %3, er2\n\t"                \
			"jsr @_resume\n\t"                  \
                        "mov.l  er2,%0\n\t"                 \
		       : "=r" (_last)			    \
		       : "r" (&(prev->thread)),		    \
			 "r" (&(next->thread)),		    \
                         "g" (prev)                         \
		       : "cc", "er0", "er1", "er2", "er3"); \
  (last) = _last; 					    \
}

#define __sti() asm volatile ("andc #0x7f,ccr")
#define __cli() asm volatile ("orc  #0x80,ccr")

#define __save_flags(x) \
       asm volatile ("stc ccr,%w0":"=r" (x))

#define __restore_flags(x) \
       asm volatile ("ldc %w0,ccr": :"r" (x))

#define	irqs_disabled()			\
({					\
	unsigned char flags;		\
	__save_flags(flags);	        \
	((flags & 0x80) == 0x80);	\
})

#define iret() __asm__ __volatile__ ("rte": : :"memory", "sp", "cc")

/* For spinlocks etc */
#define local_irq_disable()	__cli()
#define local_irq_enable()      __sti()
#define local_irq_save(x)	({ __save_flags(x); local_irq_disable(); })
#define local_irq_restore(x)	__restore_flags(x)
#define local_save_flags(x)     __save_flags(x)

/*
 * Force strict CPU ordering.
 * Not really required on H8...
 */
#define nop()  asm volatile ("nop"::)
#define mb()   asm volatile (""   : : :"memory")
#define rmb()  asm volatile (""   : : :"memory")
#define wmb()  asm volatile (""   : : :"memory")
#define set_rmb(var, value)    do { xchg(&var, value); } while (0)
#define set_mb(var, value)     set_rmb(var, value)
#define set_wmb(var, value)    do { var = value; wmb(); } while (0)

#ifdef CONFIG_SMP
#define smp_mb()	mb()
#define smp_rmb()	rmb()
#define smp_wmb()	wmb()
#define smp_read_barrier_depends()	read_barrier_depends()
#else
#define smp_mb()	barrier()
#define smp_rmb()	barrier()
#define smp_wmb()	barrier()
#define smp_read_barrier_depends()	do { } while(0)
#endif

#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
#define tas(ptr) (xchg((ptr),1))

struct __xchg_dummy { unsigned long a[100]; };
#define __xg(x) ((volatile struct __xchg_dummy *)(x))

static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
{
  unsigned long tmp, flags;

  local_irq_save(flags);

  switch (size) {
  case 1:
    __asm__ __volatile__
    ("mov.b %2,%0\n\t"
     "mov.b %1,%2"
    : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
    break;
  case 2:
    __asm__ __volatile__
    ("mov.w %2,%0\n\t"
     "mov.w %1,%2"
    : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
    break;
  case 4:
    __asm__ __volatile__
    ("mov.l %2,%0\n\t"
     "mov.l %1,%2"
    : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
    break;
  default:
    tmp = 0;	  
  }
  local_irq_restore(flags);
  return tmp;
}

#define HARD_RESET_NOW() ({		\
        local_irq_disable();		\
        asm("jmp @@0");			\
})

#define arch_align_stack(x) (x)

#endif /* _H8300_SYSTEM_H */
OpenPOWER on IntegriCloud