1/* 2 * include/asm-m68knommu/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/compiler.h> 17#include <linux/threads.h> 18#include <asm/types.h> 19#include <asm/segment.h> 20#include <asm/fpu.h> 21#include <asm/ptrace.h> 22#include <asm/current.h> 23 24static inline unsigned long rdusp(void) 25{ 26#ifdef CONFIG_COLDFIRE 27 extern unsigned int sw_usp; 28 return(sw_usp); 29#else 30 unsigned long usp; 31 __asm__ __volatile__("move %/usp,%0" : "=a" (usp)); 32 return usp; 33#endif 34} 35 36static inline void wrusp(unsigned long usp) 37{ 38#ifdef CONFIG_COLDFIRE 39 extern unsigned int sw_usp; 40 sw_usp = usp; 41#else 42 __asm__ __volatile__("move %0,%/usp" : : "a" (usp)); 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#define TASK_SIZE (0xF0000000UL) 51 52/* 53 * This decides where the kernel will search for a free chunk of vm 54 * space during mmap's. We won't be using it 55 */ 56#define TASK_UNMAPPED_BASE 0 57 58/* 59 * if you change this structure, you must change the code and offsets 60 * in m68k/machasm.S 61 */ 62 63struct thread_struct { 64 unsigned long ksp; /* kernel stack pointer */ 65 unsigned long usp; /* user stack pointer */ 66 unsigned short sr; /* saved status register */ 67 unsigned short fs; /* saved fs (sfc, dfc) */ 68 unsigned long crp[2]; /* cpu root pointer */ 69 unsigned long esp0; /* points to SR of stack frame */ 70 unsigned long fp[8*3]; 71 unsigned long fpcntl[3]; /* fp control regs */ 72 unsigned char fpstate[FPSTATESIZE]; /* floating point state */ 73}; 74 75#define INIT_THREAD { \ 76 sizeof(init_stack) + (unsigned long) init_stack, 0, \ 77 PS_S, __KERNEL_DS, \ 78 {0, 0}, 0, {0,}, {0, 0, 0}, {0,}, \ 79} 80 81/* 82 * Coldfire stacks need to be re-aligned on trap exit, conventional 83 * 68k can handle this case cleanly. 84 */ 85#if defined(CONFIG_COLDFIRE) 86#define reformat(_regs) do { (_regs)->format = 0x4; } while(0) 87#else 88#define reformat(_regs) do { } while (0) 89#endif 90 91/* 92 * Do necessary setup to start up a newly executed thread. 93 * 94 * pass the data segment into user programs if it exists, 95 * it can't hurt anything as far as I can tell 96 */ 97#define start_thread(_regs, _pc, _usp) \ 98do { \ 99 set_fs(USER_DS); /* reads from user space */ \ 100 (_regs)->pc = (_pc); \ 101 ((struct switch_stack *)(_regs))[-1].a6 = 0; \ 102 reformat(_regs); \ 103 if (current->mm) \ 104 (_regs)->d5 = current->mm->start_data; \ 105 (_regs)->sr &= ~0x2000; \ 106 wrusp(_usp); \ 107} while(0) 108 109/* Forward declaration, a strange C thing */ 110struct task_struct; 111 112/* Free all resources held by a thread. */ 113static inline void release_thread(struct task_struct *dead_task) 114{ 115} 116 117/* Prepare to copy thread state - unlazy all lazy status */ 118#define prepare_to_copy(tsk) do { } while (0) 119 120extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags); 121 122/* 123 * Free current thread data structures etc.. 124 */ 125static inline void exit_thread(void) 126{ 127} 128 129unsigned long thread_saved_pc(struct task_struct *tsk); 130unsigned long get_wchan(struct task_struct *p); 131 132#define KSTK_EIP(tsk) \ 133 ({ \ 134 unsigned long eip = 0; \ 135 if ((tsk)->thread.esp0 > PAGE_SIZE && \ 136 (virt_addr_valid((tsk)->thread.esp0))) \ 137 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \ 138 eip; }) 139#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp) 140 141#define cpu_relax() barrier() 142 143#endif 144