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
  21 extern inline unsigned long rdusp(void) {
  22         unsigned long usp;
  23
  24         __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
  25         return usp;
  26 }
  27
  28 extern 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
  67 struct 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  fp[8*3];
  75         unsigned long  fpcntl[3];       /* fp control regs */
  76         unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
  77 };
  78
  79 #define INIT_MMAP { &init_mm, 0, 0x40000000, NULL, __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED), VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
  80
  81 #define INIT_THREAD  { \
  82         sizeof(init_stack) + (unsigned long) init_stack, 0, \
  83         PS_S, __KERNEL_DS, \
  84         {0, 0}, 0, {0,}, {0, 0, 0}, {0,}, \
  85 }
  86
  87 /*
  88  * Do necessary setup to start up a newly executed thread.
  89  */
  90 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
  91                                 unsigned long usp)
  92 {
  93         /* reads from user space */
  94         set_fs(USER_DS);
  95
  96         regs->pc = pc;
  97         regs->sr &= ~0x2000;
  98         wrusp(usp);
  99 }
 100
 101 /* Forward declaration, a strange C thing */
 102 struct task_struct;
 103
 104 /* Free all resources held by a thread. */
 105 static inline void release_thread(struct task_struct *dead_task)
 106 {
 107 }
 108
 109 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 110
 111 #define copy_segments(tsk, mm)          do { } while (0)
 112 #define release_segments(mm)            do { } while (0)
 113 #define forget_segments()               do { } while (0)
 114
 115 /*
 116  * Free current thread data structures etc..
 117  */
 118 static inline void exit_thread(void)
 119 {
 120 }
 121
 122 /*
 123  * Return saved PC of a blocked thread.
 124  */
 125 extern inline unsigned long thread_saved_pc(struct thread_struct *t)
 126 {
 127         extern void scheduling_functions_start_here(void);
 128         extern void scheduling_functions_end_here(void);
 129         struct switch_stack *sw = (struct switch_stack *)t->ksp;
 130         /* Check whether the thread is blocked in resume() */
 131         if (sw->retpc > (unsigned long)scheduling_functions_start_here &&
 132             sw->retpc < (unsigned long)scheduling_functions_end_here)
 133                 return ((unsigned long *)sw->a6)[1];
 134         else
 135                 return sw->retpc;
 136 }
 137
 138 unsigned long get_wchan(struct task_struct *p);
 139
 140 #define KSTK_EIP(tsk)   \
 141     ({                  \
 142         unsigned long eip = 0;   \
 143         if ((tsk)->thread.esp0 > PAGE_SIZE && \
 144             MAP_NR((tsk)->thread.esp0) < max_mapnr) \
 145               eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
 146         eip; })
 147 #define KSTK_ESP(tsk)   ((tsk) == current ? rdusp() : (tsk)->thread.usp)
 148
 149 #define THREAD_SIZE (2*PAGE_SIZE)
 150
 151 /* Allocation and freeing of basic task resources. */
 152 #define alloc_task_struct() \
 153         ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
 154 #define free_task_struct(p)     free_pages((unsigned long)(p),1)
 155
 156 #define init_task       (init_task_union.task)
 157 #define init_stack      (init_task_union.stack)
 158
 159 #endif