arch/h8300/include/asm/processor.h

   1 /*
   2  * include/asm-h8300/processor.h
   3  *
   4  * Copyright (C) 2002 Yoshinori Sato
   5  *
   6  * Based on: linux/asm-m68nommu/processor.h
   7  *
   8  * Copyright (C) 1995 Hamish Macdonald
   9  */
  10
  11 #ifndef __ASM_H8300_PROCESSOR_H
  12 #define __ASM_H8300_PROCESSOR_H
  13
  14 /*
  15  * Default implementation of macro that returns current
  16  * instruction pointer ("program counter").
  17  */
  18 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
  19
  20 #include <linux/compiler.h>
  21 #include <asm/segment.h>
  22 #include <asm/fpu.h>
  23 #include <asm/ptrace.h>
  24 #include <asm/current.h>
  25
  26 static inline unsigned long rdusp(void) {
  27         extern unsigned int     sw_usp;
  28         return(sw_usp);
  29 }
  30
  31 static inline void wrusp(unsigned long usp) {
  32         extern unsigned int     sw_usp;
  33         sw_usp = usp;
  34 }
  35
  36 /*
  37  * User space process size: 3.75GB. This is hardcoded into a few places,
  38  * so don't change it unless you know what you are doing.
  39  */
  40 #define TASK_SIZE       (0xFFFFFFFFUL)
  41
  42 #ifdef __KERNEL__
  43 #define STACK_TOP       TASK_SIZE
  44 #define STACK_TOP_MAX   STACK_TOP
  45 #endif
  46
  47 /*
  48  * This decides where the kernel will search for a free chunk of vm
  49  * space during mmap's. We won't be using it
  50  */
  51 #define TASK_UNMAPPED_BASE      0
  52
  53 struct thread_struct {
  54         unsigned long  ksp;             /* kernel stack pointer */
  55         unsigned long  usp;             /* user stack pointer */
  56         unsigned long  ccr;             /* saved status register */
  57         unsigned long  esp0;            /* points to SR of stack frame */
  58         struct {
  59                 unsigned short *addr;
  60                 unsigned short inst;
  61         } breakinfo;
  62 };
  63
  64 #define INIT_THREAD  {                                          \
  65         .ksp  = sizeof(init_stack) + (unsigned long)init_stack, \
  66         .usp  = 0,                                              \
  67         .ccr  = PS_S,                                           \
  68         .esp0 = 0,                                              \
  69         .breakinfo = {                                          \
  70                 .addr = (unsigned short *)-1,                   \
  71                 .inst = 0                                       \
  72         }                                                       \
  73 }
  74
  75 /*
  76  * Do necessary setup to start up a newly executed thread.
  77  *
  78  * pass the data segment into user programs if it exists,
  79  * it can't hurt anything as far as I can tell
  80  */
  81 #if defined(__H8300H__)
  82 #define start_thread(_regs, _pc, _usp)                          \
  83 do {                                                            \
  84         set_fs(USER_DS);           /* reads from user space */  \
  85         (_regs)->pc = (_pc);                                    \
  86         (_regs)->ccr = 0x00;       /* clear all flags */        \
  87         (_regs)->er5 = current->mm->start_data; /* GOT base */  \
  88         wrusp((unsigned long)(_usp) - sizeof(unsigned long)*3); \
  89 } while(0)
  90 #endif
  91 #if defined(__H8300S__)
  92 #define start_thread(_regs, _pc, _usp)                          \
  93 do {                                                            \
  94         set_fs(USER_DS);           /* reads from user space */  \
  95         (_regs)->pc = (_pc);                                    \
  96         (_regs)->ccr = 0x00;       /* clear kernel flag */      \
  97         (_regs)->exr = 0x78;       /* enable all interrupts */  \
  98         (_regs)->er5 = current->mm->start_data; /* GOT base */  \
  99         /* 14 = space for retaddr(4), vector(4), er0(4) and ext(2) on stack */ \
 100         wrusp(((unsigned long)(_usp)) - 14);                    \
 101 } while(0)
 102 #endif
 103
 104 /* Forward declaration, a strange C thing */
 105 struct task_struct;
 106
 107 /* Free all resources held by a thread. */
 108 static inline void release_thread(struct task_struct *dead_task)
 109 {
 110 }
 111
 112 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 113
 114 #define prepare_to_copy(tsk)    do { } while (0)
 115
 116 /*
 117  * Free current thread data structures etc..
 118  */
 119 static inline void exit_thread(void)
 120 {
 121 }
 122
 123 /*
 124  * Return saved PC of a blocked thread.
 125  */
 126 unsigned long thread_saved_pc(struct task_struct *tsk);
 127 unsigned long get_wchan(struct task_struct *p);
 128
 129 #define KSTK_EIP(tsk)   \
 130     ({                  \
 131         unsigned long eip = 0;   \
 132         if ((tsk)->thread.esp0 > PAGE_SIZE && \
 133             MAP_NR((tsk)->thread.esp0) < max_mapnr) \
 134               eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
 135         eip; })
 136 #define KSTK_ESP(tsk)   ((tsk) == current ? rdusp() : (tsk)->thread.usp)
 137
 138 #define cpu_relax()    barrier()
 139
 140 #endif