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/thread_info.h>
  17 #include <asm/segment.h>
  18 #include <asm/fpu.h>
  19 #include <asm/ptrace.h>
  20
  21 static inline unsigned long rdusp(void)
  22 {
  23         unsigned long usp;
  24
  25         __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
  26         return usp;
  27 }
  28
  29 static inline void wrusp(unsigned long usp)
  30 {
  31         __asm__ __volatile__("move %0,%/usp" : : "a" (usp));
  32 }
  33
  34 /*
  35  * User space process size: 3.75GB. This is hardcoded into a few places,
  36  * so don't change it unless you know what you are doing.
  37  */
  38 #ifndef CONFIG_SUN3
  39 #define TASK_SIZE       (0xF0000000UL)
  40 #else
  41 #define TASK_SIZE       (0x0E000000UL)
  42 #endif
  43
  44 /* This decides where the kernel will search for a free chunk of vm
  45  * space during mmap's.
  46  */
  47 #ifndef CONFIG_SUN3
  48 #define TASK_UNMAPPED_BASE      0xC0000000UL
  49 #else
  50 #define TASK_UNMAPPED_BASE      0x0A000000UL
  51 #endif
  52 #define TASK_UNMAPPED_ALIGN(addr, off)  PAGE_ALIGN(addr)
  53
  54 struct thread_struct {
  55         unsigned long  ksp;             /* kernel stack pointer */
  56         unsigned long  usp;             /* user stack pointer */
  57         unsigned short sr;              /* saved status register */
  58         unsigned short fs;              /* saved fs (sfc, dfc) */
  59         unsigned long  crp[2];          /* cpu root pointer */
  60         unsigned long  esp0;            /* points to SR of stack frame */
  61         unsigned long  faddr;           /* info about last fault */
  62         int            signo, code;
  63         unsigned long  fp[8*3];
  64         unsigned long  fpcntl[3];       /* fp control regs */
  65         unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
  66         struct thread_info info;
  67 };
  68
  69 #define INIT_THREAD  {                                                  \
  70         .ksp    = sizeof(init_stack) + (unsigned long) init_stack,      \
  71         .sr     = PS_S,                                                 \
  72         .fs     = __KERNEL_DS,                                          \
  73         .info   = INIT_THREAD_INFO(init_task),                          \
  74 }
  75
  76 /*
  77  * Do necessary setup to start up a newly executed thread.
  78  */
  79 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
  80                                 unsigned long usp)
  81 {
  82         /* reads from user space */
  83         set_fs(USER_DS);
  84
  85         regs->pc = pc;
  86         regs->sr &= ~0x2000;
  87         wrusp(usp);
  88 }
  89
  90 /* Forward declaration, a strange C thing */
  91 struct task_struct;
  92
  93 /* Free all resources held by a thread. */
  94 static inline void release_thread(struct task_struct *dead_task)
  95 {
  96 }
  97
  98 /* Prepare to copy thread state - unlazy all lazy status */
  99 #define prepare_to_copy(tsk)    do { } while (0)
 100
 101 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 102
 103 /*
 104  * Free current thread data structures etc..
 105  */
 106 static inline void exit_thread(void)
 107 {
 108 }
 109
 110 extern unsigned long thread_saved_pc(struct task_struct *tsk);
 111
 112 unsigned long get_wchan(struct task_struct *p);
 113
 114 #define KSTK_EIP(tsk)   \
 115     ({                  \
 116         unsigned long eip = 0;   \
 117         if ((tsk)->thread.esp0 > PAGE_SIZE && \
 118             (virt_addr_valid((tsk)->thread.esp0))) \
 119               eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
 120         eip; })
 121 #define KSTK_ESP(tsk)   ((tsk) == current ? rdusp() : (tsk)->thread.usp)
 122
 123 #define cpu_relax()     barrier()
 124
 125 #endif