LXR linux-old/include/asm-m68k/processor.h

   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/config.h>
  17#include <asm/segment.h>
  18#include <asm/fpu.h>
  19#include <asm/ptrace.h>
  20
  21extern inline unsigned long rdusp(void) {
  22        unsigned long usp;
  23
  24        __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
  25        return usp;
  26}
  27
  28extern inline void wrusp(unsigned long usp) {
  29        __asm__ __volatile__("move %0,%/usp" : : "a" (usp));
  30}
  31
  32/*
  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.
  35 */
  36#ifndef CONFIG_SUN3
  37#define TASK_SIZE       (0xF0000000UL)
  38#else
  39#ifdef __ASSEMBLY__
  40#define TASK_SIZE       (0x0E000000)
  41#else
  42#define TASK_SIZE       (0x0E000000UL)
  43#endif
  44#endif
  45
  46/* This decides where the kernel will search for a free chunk of vm
  47 * space during mmap's.
  48 */
  49#ifndef CONFIG_SUN3
  50#define TASK_UNMAPPED_BASE      0xC0000000UL
  51#else
  52#define TASK_UNMAPPED_BASE      0x0A000000UL
  53#endif
  54#define TASK_UNMAPPED_ALIGN(addr, off)  PAGE_ALIGN(addr)
  55
  56/*
  57 * Bus types
  58 */
  59#define EISA_bus 0
  60#define MCA_bus 0
  61
  62/* 
  63 * if you change this structure, you must change the code and offsets
  64 * in m68k/machasm.S
  65 */
  66   
  67struct 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 */
  75        int            signo, code;
  76        unsigned long  fp[8*3];
  77        unsigned long  fpcntl[3];       /* fp control regs */
  78        unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
  79};
  80
  81#define INIT_THREAD  { \
  82        sizeof(init_stack) + (unsigned long) init_stack, 0, \
  83        PS_S, __KERNEL_DS, \
  84}
  85
  86/*
  87 * Do necessary setup to start up a newly executed thread.
  88 */
  89static inline void start_thread(struct pt_regs * regs, unsigned long pc,
  90                                unsigned long usp)
  91{
  92        /* reads from user space */
  93        set_fs(USER_DS);
  94
  95        regs->pc = pc;
  96        regs->sr &= ~0x2000;
  97        wrusp(usp);
  98}
  99
 100/* Forward declaration, a strange C thing */
 101struct task_struct;
 102
 103/* Free all resources held by a thread. */
 104static inline void release_thread(struct task_struct *dead_task)
 105{
 106}
 107
 108extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 109
 110#define copy_segments(tsk, mm)          do { } while (0)
 111#define release_segments(mm)            do { } while (0)
 112
 113/*
 114 * Free current thread data structures etc..
 115 */
 116static inline void exit_thread(void)
 117{
 118}
 119
 120/*
 121 * Return saved PC of a blocked thread.
 122 */
 123extern inline unsigned long thread_saved_pc(struct thread_struct *t)
 124{
 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];
 132        else
 133                return sw->retpc;
 134}
 135
 136unsigned long get_wchan(struct task_struct *p);
 137
 138#define KSTK_EIP(tsk)   \
 139    ({                  \
 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; \
 144        eip; })
 145#define KSTK_ESP(tsk)   ((tsk) == current ? rdusp() : (tsk)->thread.usp)
 146
 147#define THREAD_SIZE (2*PAGE_SIZE)
 148
 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)
 154
 155#define init_task       (init_task_union.task)
 156#define init_stack      (init_task_union.stack)
 157
 158#define cpu_relax()     do { } while (0)
 159
 160#endif
 161