summaryrefslogtreecommitdiffstats
path: root/include/asm-m68k/processor.h
blob: 0ad99a7f8936d7f28a929d96275ec95fdd6ed808 (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
148
149
150
151
152
153
154
155
156
157
158
159
160
/*
 * include/asm-m68k/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/config.h>
#include <asm/segment.h>
#include <asm/fpu.h>
#include <asm/ptrace.h>

extern inline unsigned long rdusp(void) {
  	unsigned long usp;

	__asm__ __volatile__("move %/usp,%0" : "=a" (usp));
	return usp;
}

extern inline void wrusp(unsigned long usp) {
	__asm__ __volatile__("move %0,%/usp" : : "a" (usp));
}

/*
 * 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.
 */
#ifndef CONFIG_SUN3
#define TASK_SIZE	(0xF0000000UL)
#else
#ifdef __ASSEMBLY__
#define TASK_SIZE	(0x0E000000)
#else
#define TASK_SIZE	(0x0E000000UL)
#endif
#endif

/* This decides where the kernel will search for a free chunk of vm
 * space during mmap's.
 */
#ifndef CONFIG_SUN3
#define TASK_UNMAPPED_BASE	0xC0000000UL
#else
#define TASK_UNMAPPED_BASE	0x0A000000UL
#endif
#define TASK_UNMAPPED_ALIGN(addr, off)	PAGE_ALIGN(addr)

/*
 * Bus types
 */
#define EISA_bus 0
#define MCA_bus 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  faddr;		/* info about last fault */
	int            signo, code;
	unsigned long  fp[8*3];
	unsigned long  fpcntl[3];	/* fp control regs */
	unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
};

#define INIT_MMAP { &init_mm, 0, 0x40000000, NULL, __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED), VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }

#define INIT_THREAD  { \
	sizeof(init_stack) + (unsigned long) init_stack, 0, \
	PS_S, __KERNEL_DS, \
}

/*
 * Do necessary setup to start up a newly executed thread.
 */
static inline void start_thread(struct pt_regs * regs, unsigned long pc,
				unsigned long usp)
{
	/* reads from user space */
	set_fs(USER_DS);

	regs->pc = pc;
	regs->sr &= ~0x2000;
	wrusp(usp);
}

/* 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)
{
}

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

#define copy_segments(tsk, mm)		do { } while (0)
#define release_segments(mm)		do { } while (0)

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

/*
 * Return saved PC of a blocked thread.
 */
extern inline unsigned long thread_saved_pc(struct thread_struct *t)
{
	extern void scheduling_functions_start_here(void);
	extern void scheduling_functions_end_here(void);
	struct switch_stack *sw = (struct switch_stack *)t->ksp;
	/* Check whether the thread is blocked in resume() */
	if (sw->retpc > (unsigned long)scheduling_functions_start_here &&
	    sw->retpc < (unsigned long)scheduling_functions_end_here)
		return ((unsigned long *)sw->a6)[1];
	else
		return sw->retpc;
}

unsigned long get_wchan(struct task_struct *p);

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

#define THREAD_SIZE (2*PAGE_SIZE)

/* Allocation and freeing of basic task resources. */
#define alloc_task_struct() \
	((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
#define free_task_struct(p)	free_pages((unsigned long)(p),1)
#define get_task_struct(tsk)      atomic_inc(&virt_to_page(tsk)->count)

#define init_task	(init_task_union.task)
#define init_stack	(init_task_union.stack)

#endif