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#if defined(CONFIG_COLDFIRE)
52#define TASK_SIZE (0xC0000000UL)
53#elif defined(CONFIG_SUN3)
54#define TASK_SIZE (0x0E000000UL)
55#else
56#define TASK_SIZE (0xF0000000UL)
57#endif
58#else
59#define TASK_SIZE (0xFFFFFFFFUL)
60#endif
61
62#ifdef __KERNEL__
63#define STACK_TOP TASK_SIZE
64#define STACK_TOP_MAX STACK_TOP
65#endif
66
67/* This decides where the kernel will search for a free chunk of vm
68 * space during mmap's.
69 */
70#ifdef CONFIG_MMU
71#if defined(CONFIG_COLDFIRE)
72#define TASK_UNMAPPED_BASE 0x60000000UL
73#elif defined(CONFIG_SUN3)
74#define TASK_UNMAPPED_BASE 0x0A000000UL
75#else
76#define TASK_UNMAPPED_BASE 0xC0000000UL
77#endif
78#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
79#else
80#define TASK_UNMAPPED_BASE 0
81#endif
82
83struct thread_struct {
84 unsigned long ksp; /* kernel stack pointer */
85 unsigned long usp; /* user stack pointer */
86 unsigned short sr; /* saved status register */
87 unsigned short fs; /* saved fs (sfc, dfc) */
88 unsigned long crp[2]; /* cpu root pointer */
89 unsigned long esp0; /* points to SR of stack frame */
90 unsigned long faddr; /* info about last fault */
91 int signo, code;
92 unsigned long fp[8*3];
93 unsigned long fpcntl[3]; /* fp control regs */
94 unsigned char fpstate[FPSTATESIZE]; /* floating point state */
95};
96
97#define INIT_THREAD { \
98 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
99 .sr = PS_S, \
100 .fs = __KERNEL_DS, \
101}
102
103#ifdef CONFIG_MMU
104/*
105 * Do necessary setup to start up a newly executed thread.
106 */
107static inline void start_thread(struct pt_regs * regs, unsigned long pc,
108 unsigned long usp)
109{
110 regs->pc = pc;
111 regs->sr &= ~0x2000;
112 wrusp(usp);
113}
114
115extern int handle_kernel_fault(struct pt_regs *regs);
116
117#else
118
119/*
120 * Coldfire stacks need to be re-aligned on trap exit, conventional
121 * 68k can handle this case cleanly.
122 */
123#ifdef CONFIG_COLDFIRE
124#define reformat(_regs) do { (_regs)->format = 0x4; } while(0)
125#else
126#define reformat(_regs) do { } while (0)
127#endif
128
129#define start_thread(_regs, _pc, _usp) \
130do { \
131 (_regs)->pc = (_pc); \
132 ((struct switch_stack *)(_regs))[-1].a6 = 0; \
133 reformat(_regs); \
134 if (current->mm) \
135 (_regs)->d5 = current->mm->start_data; \
136 (_regs)->sr &= ~0x2000; \
137 wrusp(_usp); \
138} while(0)
139
140static inline int handle_kernel_fault(struct pt_regs *regs)
141{
142 /* Any fault in kernel is fatal on non-mmu */
143 return 0;
144}
145
146#endif
147
148/* Forward declaration, a strange C thing */
149struct task_struct;
150
151/* Free all resources held by a thread. */
152static inline void release_thread(struct task_struct *dead_task)
153{
154}
155
156/* Prepare to copy thread state - unlazy all lazy status */
157#define prepare_to_copy(tsk) do { } while (0)
158
159extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
160
161/*
162 * Free current thread data structures etc..
163 */
164static inline void exit_thread(void)
165{
166}
167
168extern unsigned long thread_saved_pc(struct task_struct *tsk);
169
170unsigned long get_wchan(struct task_struct *p);
171
172#define KSTK_EIP(tsk) \
173 ({ \
174 unsigned long eip = 0; \
175 if ((tsk)->thread.esp0 > PAGE_SIZE && \
176 (virt_addr_valid((tsk)->thread.esp0))) \
177 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
178 eip; })
179#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
180
181#define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
182
183#define cpu_relax() barrier()
184
185#endif