aboutsummaryrefslogtreecommitdiff
path: root/arch/m68k/include/asm/processor_no.h
blob: 7a1e0ba35f5adaf90111835ca718b832e1da5810 (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
/*
 * include/asm-m68knommu/processor.h
 *
 * Copyright (C) 1995 Hamish Macdonald
 */

#ifndef __ASM_M68K_PROCESSOR_H
#define __ASM_M68K_PROCESSOR_H

/*
 * Default implementation of macro that returns current
 * instruction pointer ("program counter").
 */
#define current_text_addr() ({ __label__ _l; _l: &&_l;})

#include <linux/compiler.h>
#include <linux/threads.h>
#include <asm/types.h>
#include <asm/segment.h>
#include <asm/fpu.h>
#include <asm/ptrace.h>
#include <asm/current.h>

static inline unsigned long rdusp(void)
{
#ifdef CONFIG_COLDFIRE
	extern unsigned int sw_usp;
	return(sw_usp);
#else
  	unsigned long usp;
	__asm__ __volatile__("move %/usp,%0" : "=a" (usp));
	return usp;
#endif
}

static inline void wrusp(unsigned long usp)
{
#ifdef CONFIG_COLDFIRE
	extern unsigned int sw_usp;
	sw_usp = usp;
#else
	__asm__ __volatile__("move %0,%/usp" : : "a" (usp));
#endif
}

/*
 * User space process size: 3.75GB. This is hardcoded into a few places,
 * so don't change it unless you know what you are doing.
 */
#define TASK_SIZE	(0xF0000000UL)

/*
 * This decides where the kernel will search for a free chunk of vm
 * space during mmap's. We won't be using it
 */
#define TASK_UNMAPPED_BASE	0

/* 
 * if you change this structure, you must change the code and offsets
 * in m68k/machasm.S
 */
   
struct thread_struct {
	unsigned long  ksp;		/* kernel stack pointer */
	unsigned long  usp;		/* user stack pointer */
	unsigned short sr;		/* saved status register */
	unsigned short fs;		/* saved fs (sfc, dfc) */
	unsigned long  crp[2];		/* cpu root pointer */
	unsigned long  esp0;		/* points to SR of stack frame */
	unsigned long  fp[8*3];
	unsigned long  fpcntl[3];	/* fp control regs */
	unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
};

#define INIT_THREAD  {							\
	.ksp	= sizeof(init_stack) + (unsigned long) init_stack,	\
	.sr	= PS_S,							\
	.fs	= __KERNEL_DS,						\
}

/*
 * Coldfire stacks need to be re-aligned on trap exit, conventional
 * 68k can handle this case cleanly.
 */
#if defined(CONFIG_COLDFIRE)
#define	reformat(_regs)		do { (_regs)->format = 0x4; } while(0)
#else
#define	reformat(_regs)		do { } while (0)
#endif

/*
 * Do necessary setup to start up a newly executed thread.
 *
 * pass the data segment into user programs if it exists,
 * it can't hurt anything as far as I can tell
 */
#define start_thread(_regs, _pc, _usp)			\
do {							\
	set_fs(USER_DS); /* reads from user space */	\
	(_regs)->pc = (_pc);				\
	((struct switch_stack *)(_regs))[-1].a6 = 0;	\
	reformat(_regs);				\
	if (current->mm)				\
		(_regs)->d5 = current->mm->start_data;	\
	(_regs)->sr &= ~0x2000;				\
	wrusp(_usp);					\
} while(0)

/* Forward declaration, a strange C thing */
struct task_struct;

/* Free all resources held by a thread. */
static inline void release_thread(struct task_struct *dead_task)
{
}

/* Prepare to copy thread state - unlazy all lazy status */
#define prepare_to_copy(tsk)	do { } while (0)

extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);

/*
 * Free current thread data structures etc..
 */
static inline void exit_thread(void)
{
}

unsigned long thread_saved_pc(struct task_struct *tsk);
unsigned long get_wchan(struct task_struct *p);

#define	KSTK_EIP(tsk)	\
    ({			\
	unsigned long eip = 0;	 \
	if ((tsk)->thread.esp0 > PAGE_SIZE && \
	    (virt_addr_valid((tsk)->thread.esp0))) \
	      eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
	eip; })
#define	KSTK_ESP(tsk)	((tsk) == current ? rdusp() : (tsk)->thread.usp)

#define cpu_relax()    barrier()

#endif