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 #ifdef __KERNEL__
  45 #define STACK_TOP       TASK_SIZE
  46 #define STACK_TOP_MAX   STACK_TOP
  47 #endif
  48
  49 /* This decides where the kernel will search for a free chunk of vm
  50  * space during mmap's.
  51  */
  52 #ifndef CONFIG_SUN3
  53 #define TASK_UNMAPPED_BASE      0xC0000000UL
  54 #else
  55 #define TASK_UNMAPPED_BASE      0x0A000000UL
  56 #endif
  57 #define TASK_UNMAPPED_ALIGN(addr, off)  PAGE_ALIGN(addr)
  58
  59 struct thread_struct {
  60         unsigned long  ksp;             /* kernel stack pointer */
  61         unsigned long  usp;             /* user stack pointer */
  62         unsigned short sr;              /* saved status register */
  63         unsigned short fs;              /* saved fs (sfc, dfc) */
  64         unsigned long  crp[2];          /* cpu root pointer */
  65         unsigned long  esp0;            /* points to SR of stack frame */
  66         unsigned long  faddr;           /* info about last fault */
  67         int            signo, code;
  68         unsigned long  fp[8*3];
  69         unsigned long  fpcntl[3];       /* fp control regs */
  70         unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
  71         struct thread_info info;
  72 };
  73
  74 #define INIT_THREAD  {                                                  \
  75         .ksp    = sizeof(init_stack) + (unsigned long) init_stack,      \
  76         .sr     = PS_S,                                                 \
  77         .fs     = __KERNEL_DS,                                          \
  78         .info   = INIT_THREAD_INFO(init_task),                          \
  79 }
  80
  81 /*
  82  * Do necessary setup to start up a newly executed thread.
  83  */
  84 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
  85                                 unsigned long usp)
  86 {
  87         /* reads from user space */
  88         set_fs(USER_DS);
  89
  90         regs->pc = pc;
  91         regs->sr &= ~0x2000;
  92         wrusp(usp);
  93 }
  94
  95 /* Forward declaration, a strange C thing */
  96 struct task_struct;
  97
  98 /* Free all resources held by a thread. */
  99 static inline void release_thread(struct task_struct *dead_task)
 100 {
 101 }
 102
 103 /* Prepare to copy thread state - unlazy all lazy status */
 104 #define prepare_to_copy(tsk)    do { } while (0)
 105
 106 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 107
 108 /*
 109  * Free current thread data structures etc..
 110  */
 111 static inline void exit_thread(void)
 112 {
 113 }
 114
 115 extern unsigned long thread_saved_pc(struct task_struct *tsk);
 116
 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()     barrier()
 129
 130 #endif