summaryrefslogtreecommitdiffstats
path: root/arch/m68k/include/asm/processor.h
blob: 278c69bad57a8369a542851df92571cdcf988447 (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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
/*
 * 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/thread_info.h>
#include <asm/segment.h>
#include <asm/fpu.h>
#include <asm/ptrace.h>

static inline unsigned long rdusp(void)
{
#ifdef CONFIG_COLDFIRE_SW_A7
	extern unsigned int sw_usp;
	return sw_usp;
#else
	register unsigned long usp __asm__("a0");
	/* move %usp,%a0 */
	__asm__ __volatile__(".word 0x4e68" : "=a" (usp));
	return usp;
#endif
}

static inline void wrusp(unsigned long usp)
{
#ifdef CONFIG_COLDFIRE_SW_A7
	extern unsigned int sw_usp;
	sw_usp = usp;
#else
	register unsigned long a0 __asm__("a0") = usp;
	/* move %a0,%usp */
	__asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
#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.
 */
#ifdef CONFIG_MMU
#ifndef CONFIG_SUN3
#define TASK_SIZE	(0xF0000000UL)
#else
#define TASK_SIZE	(0x0E000000UL)
#endif
#else
#define TASK_SIZE	(0xFFFFFFFFUL)
#endif

#ifdef __KERNEL__
#define STACK_TOP	TASK_SIZE
#define STACK_TOP_MAX	STACK_TOP
#endif

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

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 */
	struct thread_info info;
};

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

#ifdef CONFIG_MMU
/*
 * 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);
}

#else

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

#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)

#endif

/* 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)
{
}

extern 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 task_pt_regs(tsk)	((struct pt_regs *) ((tsk)->thread.esp0))

#define cpu_relax()	barrier()

#endif
OpenPOWER on IntegriCloud