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 (SH3 SH4 Virtual storage version)
 */

#include "segmgr.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	TRAP_KILLPROC	/* Process forced termination request from BMS */

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

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

/*
 * Structure of interrupt stack at exception handler entry
 */
typedef struct {
	UW	r0_bank1;
	UW	spc;
	UW	ssr;
	UW	mdr;
	UW	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 void _SysExcHdr( UW exccode, UW excinfo, ExcStack *isp );
LOCAL void SysExcHdr( UW exccode, UW excinfo );
LOCAL ER RegistPageFaultHdr( void );

#define TSD_HDR_VAL_3		3
#define TSD_SEH_SFT_2		2U
#define TSD_IEM_SFT_5		5
#define TSD_HDR_MSK_15		15
#define TSD_PFH_VAL_M1		(-1)
#define TSD_SEH_VAL_0X160	0x160U
#define TSD_RSH_DHL_0X1000	0x1000U
#define TSD_IEM_STK_2048	2048

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

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

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

/*
 * Indicate task register value
 *	PC: 12345678 SR: 12345678 MDR:12345678
 *	R0: 12345678 R1: 12345678 R2: 12345678 R3: 12345678
 *	R4: 12345678 R5: 12345678 R6: 12345678 R7: 12345678
 *	R8: 12345678 R9: 12345678 R10:12345678 R11:12345678
 *	R12:12345678 R13:12345678 R14:12345678
 *	MAC:12345678 12345678     GBR:12345678 PR: 12345678
 *	USP:12345678 SSP:12345678 LSID:1234   UATB:12345678
 */
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) % (UW)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 = 0U;
			}
			ExcMsg_cnt--;
			break;
		}
		EI(imask);

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

/*
 * System exception handling task
 */
LOCAL void SysExcTsk( void )
{
#if USE_PROCESS_MANAGER
IMPORT	WER	_snd_hdr_msg( MESSAGE *msg, W opt );	/* Message management */
#endif
	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);
			LockSEG();
			if ( excmsg.i.exccode != EXC_TLBPRO_W ) {
				er = PageIn((VP)excmsg.i.excaddr, lsid);
			} else {
				er = CopyOnWrite((VP)excmsg.i.excaddr, lsid);
			}
			if ( er >= E_OK ) {
				/* Load into TLB. */
				UW pte = GET_PTE((VP)excmsg.i.excaddr, lsid);
				UpdateTLB((VP)excmsg.i.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));
		}

#if USE_PROCESS_MANAGER
		/* 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) - offsetof(EXCMESG, taskid));
		msg.taskid = excmsg.i.taskid;
		msg.procid = pinfo->procid;
		msg.exccode = excmsg.i.exccode;
		msg.excinfo = excmsg.i.excinfo;
		msg.excaddr = excmsg.i.excaddr;

		/* 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);
		}
#endif
	}

system_down:
	/* Use BMS to output message. */
	BMS_DEBUG_PRINT(("\n***** OS SYSTEM DOWN *****\n"));
	BMS_DEBUG_PRINT(("INT:%03x TEA:%08x tid:%d\n",
		excmsg.i.exccode, excmsg.i.excaddr, excmsg.i.taskid));
	print_regs(excmsg.i.taskid);
	tm_monitor();	/* To BMS */
}

/*
 * Body of system exception handler
 */
LOCAL void _SysExcHdr( UW exccode, UW excinfo, ExcStack *isp )
{
	ExcMsg		excmsg;
	PINFO		*pinfo;
	ER		er;

	memset(&excmsg, 0, (size_t)sizeof(excmsg));
	excmsg.i.exccode = exccode;
	excmsg.i.excinfo = excinfo;
	excmsg.i.excaddr = *(_UW*)TEA;
	excmsg.pgfault = FALSE;

	if ( (exccode == TSD_SEH_VAL_0X160) /*TRAPA*/
	  && (excinfo == ((UW)BMS_KILL_PROC << TSD_SEH_SFT_2)) ) {
		/* Not considered as BMS_KILL_PROC request
		   when called from CPL > 0. */
		if ( (isp->mdr & MDR_CPL(TSD_HDR_VAL_3)) == 0U ) {
			/* In the case of BMS_KILL_PROC, its immediately preceding stack
			   indicates the actual state at the occurrence of exception. */
			isp = (ExcStack*)&isp->usp;
			excmsg.killproc = TRUE;
			/* Turn back interrupt stack. */
			Asm("ldc %0, r6_bank":: "r"(isp));
		}
	}

	/* Obtain intended task ID */
	excmsg.i.taskid = er = tk_get_tid();
	if ( er < E_OK ) {
		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->ssr & SR_I(TSD_HDR_MSK_15)) > 0U)
	  || TaskIndependent(isp) ) {
		goto system_down;
	}

	/* Notify BDM of the exception. */
	er = BDM_NotifyException(&excmsg.i);
	if ( er == E_OK ) {
		return;
	}
	/* 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->mdr & MDR_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->mdr & MDR_CPL(TSD_HDR_VAL_3)) < MDR_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;

	/** Use BMS to indicate messages **/