2 * include/asm-m68k/processor.h
4 * Copyright (C) 1995 Hamish Macdonald
7 #ifndef __ASM_M68K_PROCESSOR_H
8 #define __ASM_M68K_PROCESSOR_H
11 * Default implementation of macro that returns current
12 * instruction pointer ("program counter").
14 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
16 #include <linux/config.h>
17 #include <asm/segment.h>
19 #include <asm/ptrace.h>
21 extern inline unsigned long rdusp(void) {
24 __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
28 extern inline void wrusp(unsigned long usp) {
29 __asm__ __volatile__("move %0,%/usp" : : "a" (usp));
33 * User space process size: 3.75GB. This is hardcoded into a few places,
34 * so don't change it unless you know what you are doing.
37 #define TASK_SIZE (0xF0000000UL)
40 #define TASK_SIZE (0x0E000000)
42 #define TASK_SIZE (0x0E000000UL)
46 /* This decides where the kernel will search for a free chunk of vm
47 * space during mmap's.
50 #define TASK_UNMAPPED_BASE 0xC0000000UL
52 #define TASK_UNMAPPED_BASE 0x0A000000UL
54 #define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
63 * if you change this structure, you must change the code and offsets
67 struct thread_struct {
68 unsigned long ksp; /* kernel stack pointer */
69 unsigned long usp; /* user stack pointer */
70 unsigned short sr; /* saved status register */
71 unsigned short fs; /* saved fs (sfc, dfc) */
72 unsigned long crp[2]; /* cpu root pointer */
73 unsigned long esp0; /* points to SR of stack frame */
74 unsigned long faddr; /* info about last fault */
76 unsigned long fp[8*3];
77 unsigned long fpcntl[3]; /* fp control regs */
78 unsigned char fpstate[FPSTATESIZE]; /* floating point state */
81 #define INIT_THREAD { \
82 sizeof(init_stack) + (unsigned long) init_stack, 0, \
87 * Do necessary setup to start up a newly executed thread.
89 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
92 /* reads from user space */
100 /* Forward declaration, a strange C thing */
103 /* Free all resources held by a thread. */
104 static inline void release_thread(struct task_struct *dead_task)
108 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
110 #define copy_segments(tsk, mm) do { } while (0)
111 #define release_segments(mm) do { } while (0)
114 * Free current thread data structures etc..
116 static inline void exit_thread(void)
121 * Return saved PC of a blocked thread.
123 extern inline unsigned long thread_saved_pc(struct thread_struct *t)
125 extern void scheduling_functions_start_here(void);
126 extern void scheduling_functions_end_here(void);
127 struct switch_stack *sw = (struct switch_stack *)t->ksp;
128 /* Check whether the thread is blocked in resume() */
129 if (sw->retpc > (unsigned long)scheduling_functions_start_here &&
130 sw->retpc < (unsigned long)scheduling_functions_end_here)
131 return ((unsigned long *)sw->a6)[1];
136 unsigned long get_wchan(struct task_struct *p);
138 #define KSTK_EIP(tsk) \
140 unsigned long eip = 0; \
141 if ((tsk)->thread.esp0 > PAGE_SIZE && \
142 (VALID_PAGE(virt_to_page((tsk)->thread.esp0)))) \
143 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
145 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
147 #define THREAD_SIZE (2*PAGE_SIZE)
149 /* Allocation and freeing of basic task resources. */
150 #define alloc_task_struct() \
151 ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
152 #define free_task_struct(p) free_pages((unsigned long)(p),1)
153 #define get_task_struct(tsk) atomic_inc(&virt_to_page(tsk)->count)
155 #define init_task (init_task_union.task)
156 #define init_stack (init_task_union.stack)
158 #define cpu_relax() do { } while (0)