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/*
104 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be
105 * true on thread creation). We need to set this explicitly.
106 */
107#ifdef CONFIG_COLDFIRE
108#define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0)
109#else
110#define setframeformat(_regs) do { } while (0)
111#endif
112
113#ifdef CONFIG_MMU
114/*
115 * Do necessary setup to start up a newly executed thread.
116 */
117static inline void start_thread(struct pt_regs * regs, unsigned long pc,
118 unsigned long usp)
119{
120 regs->pc = pc;
121 regs->sr &= ~0x2000;
122 setframeformat(regs);
123 wrusp(usp);
124}
125
126extern int handle_kernel_fault(struct pt_regs *regs);
127
128#else
129
130#define start_thread(_regs, _pc, _usp) \
131do { \
132 (_regs)->pc = (_pc); \
133 ((struct switch_stack *)(_regs))[-1].a6 = 0; \
134 setframeformat(_regs); \
135 if (current->mm) \
136 (_regs)->d5 = current->mm->start_data; \
137 (_regs)->sr &= ~0x2000; \
138 wrusp(_usp); \
139} while(0)
140
141static inline int handle_kernel_fault(struct pt_regs *regs)
142{
143 /* Any fault in kernel is fatal on non-mmu */
144 return 0;
145}
146
147#endif
148
149/* Forward declaration, a strange C thing */
150struct task_struct;
151
152/* Free all resources held by a thread. */
153static inline void release_thread(struct task_struct *dead_task)
154{
155}
156
157/*
158 * Free current thread data structures etc..
159 */
160static inline void exit_thread(void)
161{
162}
163
164extern unsigned long thread_saved_pc(struct task_struct *tsk);
165
166unsigned long get_wchan(struct task_struct *p);
167
168#define KSTK_EIP(tsk) \
169 ({ \
170 unsigned long eip = 0; \
171 if ((tsk)->thread.esp0 > PAGE_SIZE && \
172 (virt_addr_valid((tsk)->thread.esp0))) \
173 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
174 eip; })
175#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
176
177#define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
178
179#define cpu_relax() barrier()
180
181#endif