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#ifdef __ASSEMBLY__ 42#define TASK_SIZE (0x0E000000) 43#else 44#define TASK_SIZE (0x0E000000UL) 45#endif 46#endif 47 48/* This decides where the kernel will search for a free chunk of vm 49 * space during mmap's. 50 */ 51#ifndef CONFIG_SUN3 52#define TASK_UNMAPPED_BASE 0xC0000000UL 53#else 54#define TASK_UNMAPPED_BASE 0x0A000000UL 55#endif 56#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr) 57 58struct thread_struct { 59 unsigned long ksp; /* kernel stack pointer */ 60 unsigned long usp; /* user stack pointer */ 61 unsigned short sr; /* saved status register */ 62 unsigned short fs; /* saved fs (sfc, dfc) */ 63 unsigned long crp[2]; /* cpu root pointer */ 64 unsigned long esp0; /* points to SR of stack frame */ 65 unsigned long faddr; /* info about last fault */ 66 int signo, code; 67 unsigned long fp[8*3]; 68 unsigned long fpcntl[3]; /* fp control regs */ 69 unsigned char fpstate[FPSTATESIZE]; /* floating point state */ 70 struct thread_info info; 71}; 72 73#define INIT_THREAD { \ 74 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 75 .sr = PS_S, \ 76 .fs = __KERNEL_DS, \ 77 .info = INIT_THREAD_INFO(init_task), \ 78} 79 80/* 81 * Do necessary setup to start up a newly executed thread. 82 */ 83static inline void start_thread(struct pt_regs * regs, unsigned long pc, 84 unsigned long usp) 85{ 86 /* reads from user space */ 87 set_fs(USER_DS); 88 89 regs->pc = pc; 90 regs->sr &= ~0x2000; 91 wrusp(usp); 92} 93 94/* Forward declaration, a strange C thing */ 95struct task_struct; 96 97/* Free all resources held by a thread. */ 98static inline void release_thread(struct task_struct *dead_task) 99{ 100} 101 102/* Prepare to copy thread state - unlazy all lazy status */ 103#define prepare_to_copy(tsk) do { } while (0) 104 105extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags); 106 107/* 108 * Free current thread data structures etc.. 109 */ 110static inline void exit_thread(void) 111{ 112} 113 114extern unsigned long thread_saved_pc(struct task_struct *tsk); 115 116unsigned long get_wchan(struct task_struct *p); 117 118#define KSTK_EIP(tsk) \ 119 ({ \ 120 unsigned long eip = 0; \ 121 if ((tsk)->thread.esp0 > PAGE_SIZE && \ 122 (virt_addr_valid((tsk)->thread.esp0))) \ 123 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \ 124 eip; }) 125#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp) 126 127#define cpu_relax() barrier() 128 129#endif 130