Linux kernel mirror (for testing)
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linux
1/*
2 * include/asm-m68k/processor.h
3 *
4 * Copyright (C) 1995 Hamish Macdonald
5 */
6
7#ifndef __ASM_M68K_PROCESSOR_H
8#define __ASM_M68K_PROCESSOR_H
9
10/*
11 * Default implementation of macro that returns current
12 * instruction pointer ("program counter").
13 */
14#define current_text_addr() ({ __label__ _l; _l: &&_l;})
15
16#include <linux/thread_info.h>
17#include <asm/segment.h>
18#include <asm/fpu.h>
19#include <asm/ptrace.h>
20
21static inline unsigned long rdusp(void)
22{
23#ifdef CONFIG_COLDFIRE_SW_A7
24 extern unsigned int sw_usp;
25 return sw_usp;
26#else
27 register unsigned long usp __asm__("a0");
28 /* move %usp,%a0 */
29 __asm__ __volatile__(".word 0x4e68" : "=a" (usp));
30 return usp;
31#endif
32}
33
34static inline void wrusp(unsigned long usp)
35{
36#ifdef CONFIG_COLDFIRE_SW_A7
37 extern unsigned int sw_usp;
38 sw_usp = usp;
39#else
40 register unsigned long a0 __asm__("a0") = usp;
41 /* move %a0,%usp */
42 __asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
43#endif
44}
45
46/*
47 * User space process size: 3.75GB. This is hardcoded into a few places,
48 * so don't change it unless you know what you are doing.
49 */
50#ifdef CONFIG_MMU
51#ifndef CONFIG_SUN3
52#define TASK_SIZE (0xF0000000UL)
53#else
54#define TASK_SIZE (0x0E000000UL)
55#endif
56#else
57#define TASK_SIZE (0xFFFFFFFFUL)
58#endif
59
60#ifdef __KERNEL__
61#define STACK_TOP TASK_SIZE
62#define STACK_TOP_MAX STACK_TOP
63#endif
64
65/* This decides where the kernel will search for a free chunk of vm
66 * space during mmap's.
67 */
68#ifdef CONFIG_MMU
69#ifndef CONFIG_SUN3
70#define TASK_UNMAPPED_BASE 0xC0000000UL
71#else
72#define TASK_UNMAPPED_BASE 0x0A000000UL
73#endif
74#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
75#else
76#define TASK_UNMAPPED_BASE 0
77#endif
78
79struct thread_struct {
80 unsigned long ksp; /* kernel stack pointer */
81 unsigned long usp; /* user stack pointer */
82 unsigned short sr; /* saved status register */
83 unsigned short fs; /* saved fs (sfc, dfc) */
84 unsigned long crp[2]; /* cpu root pointer */
85 unsigned long esp0; /* points to SR of stack frame */
86 unsigned long faddr; /* info about last fault */
87 int signo, code;
88 unsigned long fp[8*3];
89 unsigned long fpcntl[3]; /* fp control regs */
90 unsigned char fpstate[FPSTATESIZE]; /* floating point state */
91 struct thread_info info;
92};
93
94#define INIT_THREAD { \
95 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
96 .sr = PS_S, \
97 .fs = __KERNEL_DS, \
98 .info = INIT_THREAD_INFO(init_task), \
99}
100
101#ifdef CONFIG_MMU
102/*
103 * Do necessary setup to start up a newly executed thread.
104 */
105static inline void start_thread(struct pt_regs * regs, unsigned long pc,
106 unsigned long usp)
107{
108 regs->pc = pc;
109 regs->sr &= ~0x2000;
110 wrusp(usp);
111}
112
113extern int handle_kernel_fault(struct pt_regs *regs);
114
115#else
116
117/*
118 * Coldfire stacks need to be re-aligned on trap exit, conventional
119 * 68k can handle this case cleanly.
120 */
121#ifdef CONFIG_COLDFIRE
122#define reformat(_regs) do { (_regs)->format = 0x4; } while(0)
123#else
124#define reformat(_regs) do { } while (0)
125#endif
126
127#define start_thread(_regs, _pc, _usp) \
128do { \
129 (_regs)->pc = (_pc); \
130 ((struct switch_stack *)(_regs))[-1].a6 = 0; \
131 reformat(_regs); \
132 if (current->mm) \
133 (_regs)->d5 = current->mm->start_data; \
134 (_regs)->sr &= ~0x2000; \
135 wrusp(_usp); \
136} while(0)
137
138static inline int handle_kernel_fault(struct pt_regs *regs)
139{
140 /* Any fault in kernel is fatal on non-mmu */
141 return 0;
142}
143
144#endif
145
146/* Forward declaration, a strange C thing */
147struct task_struct;
148
149/* Free all resources held by a thread. */
150static inline void release_thread(struct task_struct *dead_task)
151{
152}
153
154/* Prepare to copy thread state - unlazy all lazy status */
155#define prepare_to_copy(tsk) do { } while (0)
156
157extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
158
159/*
160 * Free current thread data structures etc..
161 */
162static inline void exit_thread(void)
163{
164}
165
166extern unsigned long thread_saved_pc(struct task_struct *tsk);
167
168unsigned long get_wchan(struct task_struct *p);
169
170#define KSTK_EIP(tsk) \
171 ({ \
172 unsigned long eip = 0; \
173 if ((tsk)->thread.esp0 > PAGE_SIZE && \
174 (virt_addr_valid((tsk)->thread.esp0))) \
175 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
176 eip; })
177#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
178
179#define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
180
181#define cpu_relax() barrier()
182
183#endif