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 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 #ifdef __ASSEMBLY__
  42 #define TASK_SIZE       (0x0E000000)
  43 #else
  44 #define TASK_SIZE       (0x0E000000UL)
  45 #endif
  46 #endif
  47
  48 /* This decides where the kernel will search for a free chunk of vm
  49  * space during mmap's.
  50  */
  51 #ifndef CONFIG_SUN3
  52 #define TASK_UNMAPPED_BASE      0xC0000000UL
  53 #else
  54 #define TASK_UNMAPPED_BASE      0x0A000000UL
  55 #endif
  56 #define TASK_UNMAPPED_ALIGN(addr, off)  PAGE_ALIGN(addr)
  57
  58 struct task_work {
  59         unsigned char sigpending;
  60         unsigned char notify_resume;    /* request for notification on
  61                                            userspace execution resumption */
  62         char          need_resched;
  63         unsigned char delayed_trace;    /* single step a syscall */
  64         unsigned char syscall_trace;    /* count of syscall interceptors */
  65         unsigned char memdie;           /* task was selected to be killed */
  66         unsigned char pad[2];
  67 };
  68
  69 struct thread_struct {
  70         unsigned long  ksp;             /* kernel stack pointer */
  71         unsigned long  usp;             /* user stack pointer */
  72         unsigned short sr;              /* saved status register */
  73         unsigned short fs;              /* saved fs (sfc, dfc) */
  74         unsigned long  crp[2];          /* cpu root pointer */
  75         unsigned long  esp0;            /* points to SR of stack frame */
  76         unsigned long  faddr;           /* info about last fault */
  77         int            signo, code;
  78         unsigned long  fp[8*3];
  79         unsigned long  fpcntl[3];       /* fp control regs */
  80         unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
  81         struct task_work work;
  82 };
  83
  84 #define INIT_THREAD  {                                                  \
  85         ksp:    sizeof(init_stack) + (unsigned long) init_stack,        \
  86         sr:     PS_S,                                                   \
  87         fs:     __KERNEL_DS,                                            \
  88         info:   INIT_THREAD_INFO(init_task)                             \
  89 }
  90
  91 /*
  92  * Do necessary setup to start up a newly executed thread.
  93  */
  94 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
  95                                 unsigned long usp)
  96 {
  97         /* reads from user space */
  98         set_fs(USER_DS);
  99
 100         regs->pc = pc;
 101         regs->sr &= ~0x2000;
 102         wrusp(usp);
 103 }
 104
 105 /* Forward declaration, a strange C thing */
 106 struct task_struct;
 107
 108 /* Free all resources held by a thread. */
 109 static inline void release_thread(struct task_struct *dead_task)
 110 {
 111 }
 112
 113 /* Prepare to copy thread state - unlazy all lazy status */
 114 #define prepare_to_copy(tsk)    do { } while (0)
 115
 116 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 117
 118 /*
 119  * Free current thread data structures etc..
 120  */
 121 static inline void exit_thread(void)
 122 {
 123 }
 124
 125 extern unsigned long thread_saved_pc(struct task_struct *tsk);
 126
 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             (virt_addr_valid((tsk)->thread.esp0))) \
 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