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/thread_info.h>
17 #include <asm/segment.h>
19 #include <asm/ptrace.h>
21 static inline unsigned long rdusp(void)
25 __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
29 static inline void wrusp(unsigned long usp)
31 __asm__ __volatile__("move %0,%/usp" : : "a" (usp));
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.
39 #define TASK_SIZE (0xF0000000UL)
41 #define TASK_SIZE (0x0E000000UL)
45 #define STACK_TOP TASK_SIZE
46 #define STACK_TOP_MAX STACK_TOP
49 /* This decides where the kernel will search for a free chunk of vm
50 * space during mmap's.
53 #define TASK_UNMAPPED_BASE 0xC0000000UL
55 #define TASK_UNMAPPED_BASE 0x0A000000UL
57 #define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
59 struct 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 */
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;
74 #define INIT_THREAD { \
75 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
78 .info = INIT_THREAD_INFO(init_task), \
82 * Do necessary setup to start up a newly executed thread.
84 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
87 /* reads from user space */
95 /* Forward declaration, a strange C thing */
98 /* Free all resources held by a thread. */
99 static inline void release_thread(struct task_struct *dead_task)
103 /* Prepare to copy thread state - unlazy all lazy status */
104 #define prepare_to_copy(tsk) do { } while (0)
106 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
109 * Free current thread data structures etc..
111 static inline void exit_thread(void)
115 extern unsigned long thread_saved_pc(struct task_struct *tsk);
117 unsigned long get_wchan(struct task_struct *p);
119 #define KSTK_EIP(tsk) \
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; \
126 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
128 #define cpu_relax() barrier()