include/asm-m68knommu/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/threads.h>
  17 #include <asm/types.h>
  18 #include <asm/segment.h>
  19 #include <asm/fpu.h>
  20 #include <asm/ptrace.h>
  21 #include <asm/current.h>
  22
  23 static inline unsigned long rdusp(void)
  24 {
  25 #ifdef CONFIG_COLDFIRE
  26         extern unsigned int sw_usp;
  27         return(sw_usp);
  28 #else
  29         unsigned long usp;
  30         __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
  31         return usp;
  32 #endif
  33 }
  34
  35 static inline void wrusp(unsigned long usp)
  36 {
  37 #ifdef CONFIG_COLDFIRE
  38         extern unsigned int sw_usp;
  39         sw_usp = usp;
  40 #else
  41         __asm__ __volatile__("move %0,%/usp" : : "a" (usp));
  42 #endif
  43 }
  44
  45 /*
  46  * User space process size: 3.75GB. This is hardcoded into a few places,
  47  * so don't change it unless you know what you are doing.
  48  */
  49 #define TASK_SIZE       (0xF0000000UL)
  50
  51 /*
  52  * This decides where the kernel will search for a free chunk of vm
  53  * space during mmap's. We won't be using it
  54  */
  55 #define TASK_UNMAPPED_BASE      0
  56
  57 /*
  58  * if you change this structure, you must change the code and offsets
  59  * in m68k/machasm.S
  60  */
  61
  62 struct thread_struct {
  63         unsigned long  ksp;             /* kernel stack pointer */
  64         unsigned long  usp;             /* user stack pointer */
  65         unsigned short sr;              /* saved status register */
  66         unsigned short fs;              /* saved fs (sfc, dfc) */
  67         unsigned long  crp[2];          /* cpu root pointer */
  68         unsigned long  esp0;            /* points to SR of stack frame */
  69         unsigned long  fp[8*3];
  70         unsigned long  fpcntl[3];       /* fp control regs */
  71         unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
  72 };
  73
  74 #define INIT_THREAD  { \
  75         sizeof(init_stack) + (unsigned long) init_stack, 0, \
  76         PS_S, __KERNEL_DS, \
  77         {0, 0}, 0, {0,}, {0, 0, 0}, {0,}, \
  78 }
  79
  80 /*
  81  * Do necessary setup to start up a newly executed thread.
  82  *
  83  * pass the data segment into user programs if it exists,
  84  * it can't hurt anything as far as I can tell
  85  */
  86 #define start_thread(_regs, _pc, _usp)           \
  87 do {                                             \
  88         set_fs(USER_DS); /* reads from user space */ \
  89         (_regs)->pc = (_pc);                         \
  90         if (current->mm)                             \
  91                 (_regs)->d5 = current->mm->start_data;   \
  92         (_regs)->sr &= ~0x2000;                      \
  93         wrusp(_usp);                                 \
  94 } while(0)
  95
  96 /* Forward declaration, a strange C thing */
  97 struct task_struct;
  98
  99 /* Free all resources held by a thread. */
 100 static inline void release_thread(struct task_struct *dead_task)
 101 {
 102 }
 103
 104 /* Prepare to copy thread state - unlazy all lazy status */
 105 #define prepare_to_copy(tsk)    do { } while (0)
 106
 107 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 108
 109 /*
 110  * Free current thread data structures etc..
 111  */
 112 static inline void exit_thread(void)
 113 {
 114 }
 115
 116 unsigned long thread_saved_pc(struct task_struct *tsk);
 117 unsigned long get_wchan(struct task_struct *p);
 118
 119 #define KSTK_EIP(tsk)   \
 120     ({                  \
 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; \
 125         eip; })
 126 #define KSTK_ESP(tsk)   ((tsk) == current ? rdusp() : (tsk)->thread.usp)
 127
 128 #define cpu_relax()    do { } while (0)
 129
 130 #endif