cp0.h

一个用在mips体系结构中的操作系统

/*
 * Copyright (C) 1996-1998 by the Board of Trustees
 *    of Leland Stanford Junior University.
 * 
 * This file is part of the SimOS distribution. 
 * See LICENSE file for terms of the license. 
 *
 */

/*****************************************************************
 * cp0.h
 * 
 * Definitions for CP0 - TLB and exception handling
 * Written for BIG ENDIAN!!!
 *
 * $Author: bosch $
 * $Date: 1998/02/10 00:30:18 $
 *****************************************************************/

#ifndef CP0_H
#define CP0_H

/* These two codes are used in mem_driver_simos.c to alert it to */
/* backdoor references */
#define NORMAL_CODE 0
#define BACKDOOR_CODE 0x100
#define EXCEPTION_CODE 0x200

/* This can only take on values up to NTLBENTRIES, but use of */
/* registers, and possible problems with sign extension make using a */
/* whole word make the most sense */
typedef uint IDX ;

extern int exceptionDuringBackdoor; 


/* This is called to allow access to the hash talbe */
IDX Tlb_Lookup( int cpuNum, uint region, VPN, ASID );

/* This is called after Tlb_Init when we are jumping into Embra to set */
/* up the entries in the TLB hash table, and the quick check*/
extern void Em_Tlb_Init( int cpuNum, int swtch );

/* This is called when we switch out of mshade, so we don't have stale data*/
/* if/when we re-enter mshade */
extern void Em_Tlb_Clear( int cpuNum );

/* Global CP0 Functions */
/* These are called from translated code */
C_LINK void Em_RestoreFromException(int cpuNum, VA restoreAddr);
C_LINK  uint Em_ProbeTLB(int cpuNum);
C_LINK  uint Em_ReadTLBEntry(int cpuNum);
C_LINK  uint Em_WriteRandomTLBEntry(int cpuNum);
C_LINK  uint Em_WriteTLBEntry(int cpuNum);
C_LINK  uint Em_MoveToC0(int cpuNum, Inst instr, VA nextPC );
/*C_LINK  void MoveFromC0(int cpuNum, unsigned gp_reg, unsigned co_reg );*/

/* Is this entry writable (dirty) in the TLB? */
int Em_Is_Tlb_Writable( int cpuNum, VA vAddr, ASID asid );
/* Is this entry readable (valid) in the TLB? */
int Em_Is_Tlb_Readable( int cpuNum, VA vAddr, ASID asid );
void Em_RaiseC1Unusable( int cpuNum );

void Em_EXCEPTION(int cpuNum, int, int);
C_LINK void Em_RaiseEXCEPTION(int cpuNum, int code, int ce);


typedef enum {ACT_DWRITE, ACT_DREAD, ACT_IREAD} Em_accesstype;

extern uint Em_TranslateVirtual(int cpuNum, VA, PA*, Em_accesstype);



struct PgMaskStruct{
   Reg  mask;
   uint loBit;
   uint offset_mask;
};

extern struct PgMaskStruct PgSz[];

#endif /* CP0_H */