i386/linux/linux-2.3.21/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 <asm/segment.h>
  17 #include <asm/fpu.h>
  18 #include <asm/ptrace.h>
  19
  20 extern inline unsigned long rdusp(void) {
  21         unsigned long usp;
  22
  23         __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
  24         return usp;
  25 }
  26
  27 extern inline void wrusp(unsigned long usp) {
  28         __asm__ __volatile__("move %0,%/usp" : : "a" (usp));
  29 }
  30
  31 /*
  32  * User space process size: 3.75GB. This is hardcoded into a few places,
  33  * so don't change it unless you know what you are doing.
  34  */
  35 #ifndef CONFIG_SUN3
  36 #define TASK_SIZE       (0xF0000000UL)
  37 #else
  38 #ifdef __ASSEMBLY__
  39 #define TASK_SIZE       (0x0E000000)
  40 #else
  41 #define TASK_SIZE       (0x0E000000UL)
  42 #endif
  43 #endif
  44
  45 /* This decides where the kernel will search for a free chunk of vm
  46  * space during mmap's.
  47  */
  48 #ifndef CONFIG_SUN3
  49 #define TASK_UNMAPPED_BASE      0xC0000000UL
  50 #else
  51 #define TASK_UNMAPPED_BASE      0x0A000000UL
  52 #endif
  53 #define TASK_UNMAPPED_ALIGN(addr, off)  PAGE_ALIGN(addr)
  54
  55 /*
  56  * Bus types
  57  */
  58 #define EISA_bus 0
  59 #define MCA_bus 0
  60
  61 /*
  62  * if you change this structure, you must change the code and offsets
  63  * in m68k/machasm.S
  64  */
  65
  66 struct thread_struct {
  67         unsigned long  ksp;             /* kernel stack pointer */
  68         unsigned long  usp;             /* user stack pointer */
  69         unsigned short sr;              /* saved status register */
  70         unsigned short fs;              /* saved fs (sfc, dfc) */
  71         unsigned long  crp[2];          /* cpu root pointer */
  72         unsigned long  esp0;            /* points to SR of stack frame */
  73         unsigned long  fp[8*3];
  74         unsigned long  fpcntl[3];       /* fp control regs */
  75         unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
  76 };
  77
  78 #define INIT_MMAP { &init_mm, 0, 0x40000000, NULL, __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED), VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
  79
  80 #define INIT_THREAD  { \
  81         sizeof(init_stack) + (unsigned long) init_stack, 0, \
  82         PS_S, __KERNEL_DS, \
  83         {0, 0}, 0, {0,}, {0, 0, 0}, {0,}, \
  84 }
  85
  86 /*
  87  * Do necessary setup to start up a newly executed thread.
  88  */
  89 static 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 */
 101 struct task_struct;
 102
 103 /* Free all resources held by a thread. */
 104 static inline void release_thread(struct task_struct *dead_task)
 105 {
 106 }
 107
 108 extern 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 #define forget_segments()               do { } while (0)
 113
 114 /*
 115  * Free current thread data structures etc..
 116  */
 117 static inline void exit_thread(void)
 118 {
 119 }
 120
 121 /*
 122  * Return saved PC of a blocked thread.
 123  */
 124 extern inline unsigned long thread_saved_pc(struct thread_struct *t)
 125 {
 126         extern void scheduling_functions_start_here(void);
 127         extern void scheduling_functions_end_here(void);
 128         struct switch_stack *sw = (struct switch_stack *)t->ksp;
 129         /* Check whether the thread is blocked in resume() */
 130         if (sw->retpc > (unsigned long)scheduling_functions_start_here &&
 131             sw->retpc < (unsigned long)scheduling_functions_end_here)
 132                 return ((unsigned long *)sw->a6)[1];
 133         else
 134                 return sw->retpc;
 135 }
 136
 137 #define THREAD_SIZE (2*PAGE_SIZE)
 138
 139 /* Allocation and freeing of basic task resources. */
 140 #define alloc_task_struct() \
 141         ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
 142 #define free_task_struct(p)     free_pages((unsigned long)(p),1)
 143
 144 #define init_task       (init_task_union.task)
 145 #define init_stack      (init_task_union.stack)
 146
 147 #endif