release/src-rt-6.x.4708/linux/linux-2.6.36/arch/m68k/include/asm/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 #ifdef CONFIG_COLDFIRE
  24         extern unsigned int sw_usp;
  25         return sw_usp;
  26 #else
  27         unsigned long usp;
  28         __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
  29         return usp;
  30 #endif
  31 }
  32
  33 static inline void wrusp(unsigned long usp)
  34 {
  35 #ifdef CONFIG_COLDFIRE
  36         extern unsigned int sw_usp;
  37         sw_usp = usp;
  38 #else
  39         __asm__ __volatile__("move %0,%/usp" : : "a" (usp));
  40 #endif
  41 }
  42
  43 /*
  44  * User space process size: 3.75GB. This is hardcoded into a few places,
  45  * so don't change it unless you know what you are doing.
  46  */
  47 #ifdef CONFIG_MMU
  48 #ifndef CONFIG_SUN3
  49 #define TASK_SIZE       (0xF0000000UL)
  50 #else
  51 #define TASK_SIZE       (0x0E000000UL)
  52 #endif
  53 #else
  54 #define TASK_SIZE       (0xFFFFFFFFUL)
  55 #endif
  56
  57 #ifdef __KERNEL__
  58 #define STACK_TOP       TASK_SIZE
  59 #define STACK_TOP_MAX   STACK_TOP
  60 #endif
  61
  62 /* This decides where the kernel will search for a free chunk of vm
  63  * space during mmap's.
  64  */
  65 #ifdef CONFIG_MMU
  66 #ifndef CONFIG_SUN3
  67 #define TASK_UNMAPPED_BASE      0xC0000000UL
  68 #else
  69 #define TASK_UNMAPPED_BASE      0x0A000000UL
  70 #endif
  71 #define TASK_UNMAPPED_ALIGN(addr, off)  PAGE_ALIGN(addr)
  72 #else
  73 #define TASK_UNMAPPED_BASE      0
  74 #endif
  75
  76 struct thread_struct {
  77         unsigned long  ksp;             /* kernel stack pointer */
  78         unsigned long  usp;             /* user stack pointer */
  79         unsigned short sr;              /* saved status register */
  80         unsigned short fs;              /* saved fs (sfc, dfc) */
  81         unsigned long  crp[2];          /* cpu root pointer */
  82         unsigned long  esp0;            /* points to SR of stack frame */
  83         unsigned long  faddr;           /* info about last fault */
  84         int            signo, code;
  85         unsigned long  fp[8*3];
  86         unsigned long  fpcntl[3];       /* fp control regs */
  87         unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
  88         struct thread_info info;
  89 };
  90
  91 #define INIT_THREAD  {                                                  \
  92         .ksp    = sizeof(init_stack) + (unsigned long) init_stack,      \
  93         .sr     = PS_S,                                                 \
  94         .fs     = __KERNEL_DS,                                          \
  95         .info   = INIT_THREAD_INFO(init_task),                          \
  96 }
  97
  98 #ifdef CONFIG_MMU
  99 /*
 100  * Do necessary setup to start up a newly executed thread.
 101  */
 102 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
 103                                 unsigned long usp)
 104 {
 105         /* reads from user space */
 106         set_fs(USER_DS);
 107
 108         regs->pc = pc;
 109         regs->sr &= ~0x2000;
 110         wrusp(usp);
 111 }
 112
 113 #else
 114
 115 /*
 116  * Coldfire stacks need to be re-aligned on trap exit, conventional
 117  * 68k can handle this case cleanly.
 118  */
 119 #ifdef CONFIG_COLDFIRE
 120 #define reformat(_regs)         do { (_regs)->format = 0x4; } while(0)
 121 #else
 122 #define reformat(_regs)         do { } while (0)
 123 #endif
 124
 125 #define start_thread(_regs, _pc, _usp)                  \
 126 do {                                                    \
 127         set_fs(USER_DS); /* reads from user space */    \
 128         (_regs)->pc = (_pc);                            \
 129         ((struct switch_stack *)(_regs))[-1].a6 = 0;    \
 130         reformat(_regs);                                \
 131         if (current->mm)                                \
 132                 (_regs)->d5 = current->mm->start_data;  \
 133         (_regs)->sr &= ~0x2000;                         \
 134         wrusp(_usp);                                    \
 135 } while(0)
 136
 137 #endif
 138
 139 /* Forward declaration, a strange C thing */
 140 struct task_struct;
 141
 142 /* Free all resources held by a thread. */
 143 static inline void release_thread(struct task_struct *dead_task)
 144 {
 145 }
 146
 147 /* Prepare to copy thread state - unlazy all lazy status */
 148 #define prepare_to_copy(tsk)    do { } while (0)
 149
 150 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 151
 152 /*
 153  * Free current thread data structures etc..
 154  */
 155 static inline void exit_thread(void)
 156 {
 157 }
 158
 159 extern unsigned long thread_saved_pc(struct task_struct *tsk);
 160
 161 unsigned long get_wchan(struct task_struct *p);
 162
 163 #define KSTK_EIP(tsk)   \
 164     ({                  \
 165         unsigned long eip = 0;   \
 166         if ((tsk)->thread.esp0 > PAGE_SIZE && \
 167             (virt_addr_valid((tsk)->thread.esp0))) \
 168               eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
 169         eip; })
 170 #define KSTK_ESP(tsk)   ((tsk) == current ? rdusp() : (tsk)->thread.usp)
 171
 172 #define task_pt_regs(tsk)       ((struct pt_regs *) ((tsk)->thread.esp0))
 173
 174 #define cpu_relax()     barrier()
 175
 176 #endif