Linux kernel mirror (for testing)
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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 unsigned long usp;
24
25 __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
26 return usp;
27}
28
29static inline void wrusp(unsigned long usp)
30{
31 __asm__ __volatile__("move %0,%/usp" : : "a" (usp));
32}
33
34/*
35 * User space process size: 3.75GB. This is hardcoded into a few places,
36 * so don't change it unless you know what you are doing.
37 */
38#ifndef CONFIG_SUN3
39#define TASK_SIZE (0xF0000000UL)
40#else
41#define TASK_SIZE (0x0E000000UL)
42#endif
43
44#ifdef __KERNEL__
45#define STACK_TOP TASK_SIZE
46#define STACK_TOP_MAX STACK_TOP
47#endif
48
49/* This decides where the kernel will search for a free chunk of vm
50 * space during mmap's.
51 */
52#ifndef CONFIG_SUN3
53#define TASK_UNMAPPED_BASE 0xC0000000UL
54#else
55#define TASK_UNMAPPED_BASE 0x0A000000UL
56#endif
57#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
58
59struct thread_struct {
60 unsigned long ksp; /* kernel stack pointer */
61 unsigned long usp; /* user stack pointer */
62 unsigned short sr; /* saved status register */
63 unsigned short fs; /* saved fs (sfc, dfc) */
64 unsigned long crp[2]; /* cpu root pointer */
65 unsigned long esp0; /* points to SR of stack frame */
66 unsigned long faddr; /* info about last fault */
67 int signo, code;
68 unsigned long fp[8*3];
69 unsigned long fpcntl[3]; /* fp control regs */
70 unsigned char fpstate[FPSTATESIZE]; /* floating point state */
71 struct thread_info info;
72};
73
74#define INIT_THREAD { \
75 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
76 .sr = PS_S, \
77 .fs = __KERNEL_DS, \
78 .info = INIT_THREAD_INFO(init_task), \
79}
80
81/*
82 * Do necessary setup to start up a newly executed thread.
83 */
84static inline void start_thread(struct pt_regs * regs, unsigned long pc,
85 unsigned long usp)
86{
87 /* reads from user space */
88 set_fs(USER_DS);
89
90 regs->pc = pc;
91 regs->sr &= ~0x2000;
92 wrusp(usp);
93}
94
95/* Forward declaration, a strange C thing */
96struct task_struct;
97
98/* Free all resources held by a thread. */
99static inline void release_thread(struct task_struct *dead_task)
100{
101}
102
103/* Prepare to copy thread state - unlazy all lazy status */
104#define prepare_to_copy(tsk) do { } while (0)
105
106extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
107
108/*
109 * Free current thread data structures etc..
110 */
111static inline void exit_thread(void)
112{
113}
114
115extern unsigned long thread_saved_pc(struct task_struct *tsk);
116
117unsigned long get_wchan(struct task_struct *p);
118
119#define KSTK_EIP(tsk) \
120 ({ \
121 unsigned long eip = 0; \
122 if ((tsk)->thread.esp0 > PAGE_SIZE && \
123 (virt_addr_valid((tsk)->thread.esp0))) \
124 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
125 eip; })
126#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
127
128#define cpu_relax() barrier()
129
130#endif