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