excmgr.c

T-kernel 的extension源代码

/*
 *----------------------------------------------------------------------
 *    T-Kernel / Standard Extension
 *
 *    Copyright (C) 2006 by Ken Sakamura. All rights reserved.
 *    T-Kernel / Standard Extension is distributed 
 *      under the T-License for T-Kernel / Standard Extension.
 *----------------------------------------------------------------------
 *
 *    Version:   1.00.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2006/8/11.
 *
 *----------------------------------------------------------------------
 */

/*
 *	excmgr.c (memory)
 *
 *	System exception handling (VR Virtual storage version)
 */

#include "segmgr.h"
#include "prcinfo.h"
#include <sys/sysexc.h>
#include <tm/tmonitor.h>
#include <sys/bdm.h>

IMPORT	void	_ExitTask( PINFO *pi, ID tskid );  /* proc/prcmgr.c */

#define	BMS_KILL_PROC	CALL_KILLPROC	/* Process forced termination request from monitor */

/* Message to system exception handling task */
typedef struct {
	BDM_ExcInfo		i;		/* Exception information */
	unsigned int		pgfault:1;	/* Page fault: TRUE */
	unsigned int		killproc:1;	/* Process forced termination request: TRUE */
} ExcMsg;

/* Message buffer for communicating with system exception handling task */
#define	MaxExcMsg		64U
#define TSD_IEM_STK_4096	(4*1024)

LOCAL ExcMsg	ExcMsg_buf[MaxExcMsg];
LOCAL UW	ExcMsg_top, ExcMsg_cnt;

LOCAL ID	SysExcTskID;		/* System exception handling task */

/*
 * Structure of exception stack at exception handler entry.
 */
typedef struct {
	DW	ssp;	/* Saved by the exception handler itself through its entry processing. */
	DW	t8;	/* Subsequently, saved through monitor's branch processing. */
	DW	t9;
	DW	epc;
	UW	taskmode;
	UW	psr;
	DW	usp;
} ExcStack;

Inline	BOOL	TaskIndependent( ExcStack *isp );

LOCAL void print_regs( ID tid );
LOCAL ER sendExcMsg( ExcMsg *msg );
LOCAL void recvExcMsg( ExcMsg *msg );
LOCAL void SysExcTsk( void );
LOCAL ER RegistPageFaultHdr( void );

#define TSD_HDR_VAL_3	3
#define TSD_SEH_VAL_3	3
#define TSD_SEH_VAL_2	2
#define TSD_PFH_VAL_M1	(-1)
#define TSD_PFH_VAL_EM1	(-1)

/*
 * Exception occurred in the task-independent section: TRUE
 */
Inline BOOL TaskIndependent( ExcStack *isp )
{
IMPORT	VP	int_stack_top;	/* Exception/interrupt stack top (T-Kernel) */
	W	n;

	n = ( (isp->taskmode & (UW)TMF_CPL(TSD_HDR_VAL_3)) > 0U )?
		(W)sizeof(ExcStack): (W)offsetof(ExcStack, usp);

	return ( ((B*)isp + n) < (B*)int_stack_top );
}

/*
 * Indicate task register value
 */
LOCAL void print_regs( ID tid )
{
#if DEBUGFUNC_SUPPORT
	T_REGS	g;
	T_EIT	e;
	T_CREGS	c;
	ER	er;

	er = tk_get_reg(tid, &g, &e, &c);
	if ( er < E_OK ) {
		BMS_DEBUG_PRINT(("- register can not read -\n"));
		return;
	}

	PrintTaskRegister(bms_printf, &g, &e, &c);
#endif /* DEBUGFUNC_SUPPORT */
}

/*
 * Send exception message
 *	Called in interrupt-disabled state
 */
LOCAL ER sendExcMsg( ExcMsg *msg )
{
	UW	pos;

	if ( ExcMsg_cnt >= (UW)MaxExcMsg ) {
		return E_LIMIT;
	}

	pos = (UW)((ExcMsg_top + ExcMsg_cnt) % MaxExcMsg);
	ExcMsg_buf[pos] = *msg;

	if ( ExcMsg_cnt++ == 0U ) {
		tk_wup_tsk(SysExcTskID);
	}

	return E_OK;
}

/*
 * Receive exception message
 */
LOCAL void recvExcMsg( ExcMsg *msg )
{
	UINT	imask;

	for ( ;; ) {
		DI(imask);
		if ( ExcMsg_cnt > 0U ) {
			*msg = ExcMsg_buf[ExcMsg_top];
			if ( ++ExcMsg_top >= (UW)MaxExcMsg ) {
				ExcMsg_top = 0;
			}
			ExcMsg_cnt--;
			break;
		}
		EI(imask);

		tk_slp_tsk(TMO_FEVR);
	}
	EI(imask);
}

/*
 * System exception handling task
 */
LOCAL void SysExcTsk( void )
{
IMPORT	WER	_snd_hdr_msg( MESSAGE *msg, W opt );	/* Message management */
	ExcMsg	excmsg;
	PINFO	*pinfo;
	ID	oldrid;
	EXCMESG	msg;
	ER	er;

	for ( ;; ) {	/* Not terminate on its own */

		/* Receive system exception */
		recvExcMsg(&excmsg);

		if ( excmsg.pgfault != 0U ) {
			/* Handle page fault */
			UW lsid = GetLSID_tid(excmsg.i.taskid);
			VP excaddr = (VP)excmsg.i.badvaddr.lo;
			LockSEG();
			if ( excmsg.i.vecno != EXC_TLBMOD ) {
				er = PageIn(excaddr, lsid);
			} else {
				er = CopyOnWrite(excaddr, lsid);
			}
			if ( er >= E_OK ) {
				/* Register in TLB */
				UW pte = GET_PTE(excaddr, lsid);
				UpdateTLB(excaddr, lsid, pte);
			}
			UnlockSEG();
			if ( er >= E_OK ) {
				/* Reopen intended task */
				er = tk_frsm_tsk(excmsg.i.taskid);
				if ( er >= E_OK ) {
					continue;
				}
			}
			DEBUG_PRINT(("SysExcTsk PageIn err = %d\n", er));
		}

		/* Obtain PINFO on exception occurrence process. */
		pinfo = GetPinfo(excmsg.i.taskid);
		if ( pinfo == NULL ) {
			goto system_down;
		}

		/* If the task is in the course of termination processing,
		   call task termination processing directly from process management. */
		if ( pinfo->exitkind != 0 ) {
			oldrid = tk_set_rid(TSK_SELF, pinfo->resid);
			_ExitTask(pinfo, excmsg.i.taskid);
			tk_set_rid(TSK_SELF, oldrid);
			continue;
		}

		if ( excmsg.killproc != 0U ) {
			goto kill_proc;
		}

		/* Send message */
		msg.type = MS_SYS1;
		msg.size = (W)sizeof(EXCMESG) - (W)offsetof(EXCMESG, taskid);
		msg.taskid = excmsg.i.taskid;
		msg.procid = pinfo->procid;
		msg.vecno    = excmsg.i.vecno;
		msg.badvaddr = excmsg.i.badvaddr;

		/* Send to exception server */
		er = _snd_hdr_msg((MESSAGE*)&msg, NOWAIT);
		if ( er <= 0 ) {
			DEBUG_PRINT(("SysExcTsk _snd_hdr_msg err = %d\n", er));

		kill_proc:
			/* If message could not be sent to exception server,
			   forcedly terminate the process. */
			tk_ras_tex(excmsg.i.taskid, 0);
			if ( excmsg.i.taskid != pinfo->tsk[0].tskid ) {
				/* Terminate main task as well. */
				tk_ras_tex(pinfo->tsk[0].tskid, 0);
			}
			pinfo->exitkind = MS_ABORT;
			tk_frsm_tsk(excmsg.i.taskid);
		}
	}

system_down:
	/* Use BMS to output message. */
	BMS_DEBUG_PRINT(("\n***** OS SYSTEM DOWN *****\n"));
	BMS_DEBUG_PRINT(("INT:%d BVA:%08x %08x tid:%d\n",
		excmsg.i.vecno, excmsg.i.badvaddr.hi, excmsg.i.badvaddr.lo,
		excmsg.i.taskid));
	print_regs(excmsg.i.taskid);
	tm_monitor();	/* To BMS */
}

/* ------------------------------------------------------------------------ */

/*
 * System exception handler
 */
EXPORT W SysExcHdr( UINT vecno, DW badvaddr )
{
	ExcStack	*isp;
	ExcMsg		excmsg;
	PINFO		*pinfo;
	ER		er;

	memset(&excmsg, 0, (size_t)sizeof(excmsg));
	excmsg.i.vecno    = vecno;
	excmsg.i.badvaddr = badvaddr;
	excmsg.pgfault    = FALSE;

	EI(0); /* Multiplex interrupt enabled */

	if ( vecno == (UW)BMS_KILL_PROC ) {
		/* Not considered as BMS_KILL_PROC request
		   when called from CPL > 0. */
		if ( (SCInfo.taskmode & (UW)TMF_PPL(TSD_SEH_VAL_3)) == 0U ) {
			/* In the case of BMS_KILL_PROC, its immediately preceding stack
			 * indicates the actual state at the occurrence of exception.
			 * Therefore, turn back the stack.
			 */
			isp = (ExcStack*)((B*)SCInfo.istkpos
					+ (sizeof(ExcStack) - (sizeof(DW) * TSD_SEH_VAL_2)));
			isp->ssp = ((ExcStack*)SCInfo.istkpos)->ssp;
			SCInfo.istkpos = isp;
			excmsg.killproc = TRUE;
		}
	}

	isp = SCInfo.istkpos;

	/* Obtain intended task ID */
	excmsg.i.taskid = tk_get_tid();
	if ( excmsg.i.taskid <= 0 ) {
		goto system_down;
	}

	/* If an exception occurs during the execution of interrupt handler (task independent
	   section) or in the interrupt-disabled state, shut down the system. */
	if ( ((isp->psr & ((UW)SR_ERL | (UW)SR_IE)) != (UW)SR_IE)
	  || TaskIndependent(isp) ) {
		goto system_down;
	}

	/* Notify BDM of the exception. */
	er = BDM_NotifyException(&excmsg.i);
	if ( er == E_OK ) {
		return 0;
	}

	/* If BDM does not exist, continue exception handling. */

	/* If an exception occurs during the execution of a task (extension, SVC, non-process,
	   etc.) within OS, shut down the system. */
	if ( ((isp->taskmode & (UW)TMF_CPL(TSD_HDR_VAL_3)) == 0U)
	  || ((pinfo = GetPinfo(excmsg.i.taskid)) == NULL) ) {
		goto system_down;
	}

	/* If the current task is a system process that is in the course of termination
	   processing, shut down the system. */
	if ( (pinfo->exitkind != 0)
	  && ((isp->taskmode & (UW)TMF_CPL(TSD_HDR_VAL_3)) < (UW)TMF_CPL(TSD_HDR_VAL_3)) ) {
		goto system_down;
	}

	/* Suspend current task */
	er = tk_sus_tsk(excmsg.i.taskid);
	if ( er < E_OK ) {
		goto system_down;
	}

	/* Notify to exception handling task */
	er = sendExcMsg(&excmsg);
	if ( er < E_OK ) {
		goto system_down;
	}

	return 0;

	/** Use BMS to indicate messages **/

system_down:
	BMS_DEBUG_PRINT(("\n***** OS SYSTEM DOWN *****\n"));
	BMS_DEBUG_PRINT(("INT:%d PC:%08x %08x PSR:%08x TMF:%08x\n"