Add an intermediate layer driver, cbus(4), to manage its own

interrupts of PC-9801 extension board slot bus (so-called 'C-bus') on
LUNA-88K2.

Existing pcex(4) is now attached at cbus(4), i.e.

cbus0 at mainbus0
pcex0 at cbus0

With this driver, some other PC-9801 boards might be supported on luna88k
in the (near?) future:-)

ok miod@

6 files changed, 379 insertions, 111 deletions

diff --git a/sys/arch/luna88k/conf/GENERIC b/sys/arch/luna88k/conf/GENERIC
index 9f9382661e4..45ff38d2b5e 100644
--- a/sys/arch/luna88k/conf/GENERIC
+++ b/sys/arch/luna88k/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.17 2014/04/16 12:01:33 aoyama Exp $
+#	$OpenBSD: GENERIC,v 1.18 2014/12/08 13:24:04 aoyama Exp $
 #
 # For further information on compiling OpenBSD kernels, see the config(8)
 # man page.
@@ -43,7 +43,8 @@ spc0		at mainbus0
 spc1		at mainbus0
 
 # PC-9801 extension board slot
-pcex0		at mainbus0
+cbus0		at mainbus0
+pcex0		at cbus0
 
 # Workstation Console attachments
 wsdisplay*	at fb?
diff --git a/sys/arch/luna88k/conf/files.luna88k b/sys/arch/luna88k/conf/files.luna88k
index 249ad97a148..69b87de8953 100644
--- a/sys/arch/luna88k/conf/files.luna88k
+++ b/sys/arch/luna88k/conf/files.luna88k
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.luna88k,v 1.21 2014/11/08 21:18:42 aoyama Exp $
+#	$OpenBSD: files.luna88k,v 1.22 2014/12/08 13:24:04 aoyama Exp $
 #
 maxpartitions 16
 
@@ -65,8 +65,12 @@ file arch/luna88k/dev/mb89352.c				spc
 #file arch/luna88k/dev/nec86hw.c			pcm needs-flag
 #file arch/luna88k/dev/nec86_luna88k.c			pcm needs-flag
 
+device cbus {}
+attach	cbus at mainbus
+file	arch/luna88k/dev/cbus.c
+
 device pcex
-attach	pcex at mainbus
+attach	pcex at cbus
 file	arch/luna88k/dev/pcex.c				pcex needs-flag
 
 # list of standard files
diff --git a/sys/arch/luna88k/dev/cbus.c b/sys/arch/luna88k/dev/cbus.c
new file mode 100644
index 00000000000..1f92b8f0ca5
--- /dev/null
+++ b/sys/arch/luna88k/dev/cbus.c
@@ -0,0 +1,297 @@
+/*	$OpenBSD: cbus.c,v 1.1 2014/12/08 13:24:04 aoyama Exp $	*/
+
+/*
+ * Copyright (c) 2014 Kenji Aoyama.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * PC-9801 extension board slot bus ('C-bus') driver for LUNA-88K2.
+ */
+
+#include <sys/param.h>
+#include <sys/device.h>
+#include <sys/malloc.h>
+#include <sys/systm.h>
+
+#include <machine/asm_macro.h>	/* ff1() */
+#include <machine/autoconf.h>
+#include <machine/board.h>	/* PC_BASE */
+
+#include <luna88k/dev/cbusvar.h>
+#include <luna88k/luna88k/isr.h>	/* isrlink_autovec() */
+
+#if 0
+#define CBUS_DEBUG
+#endif
+
+/*
+ * C-bus interrupt status register
+ */
+#define CBUS_INTR_STAT_REG	(PC_BASE + 0x1100000)
+volatile u_int8_t *cbus_isreg = (u_int8_t *)CBUS_INTR_STAT_REG;
+
+/* autoconf stuff */
+int cbus_match(struct device *, void *, void *);
+void cbus_attach(struct device *, struct device *, void *);
+int cbus_print(void *, const char *);
+
+struct cbus_softc {
+	struct device sc_dev;
+	struct cbus_isr_t cbus_isr[NCBUSISR];
+	u_int8_t registered;
+};
+
+const struct cfattach cbus_ca = {
+	sizeof(struct cbus_softc), cbus_match, cbus_attach
+};
+
+struct cfdriver cbus_cd = {
+	NULL, "cbus", DV_DULL
+};
+
+/* prototypes */
+int cbus_isrlink(int (*)(void *), void *, int, const char *);
+int cbus_isrunlink(int (*)(void *), int);
+void cbus_isrdispatch(int);
+int cbus_intr(void *);
+
+int
+cbus_match(struct device *parent, void *cf, void *aux)
+{
+	struct mainbus_attach_args *ma = aux;
+
+	if (strcmp(ma->ma_name, cbus_cd.cd_name))
+		return 0;
+#if 0
+	if (badaddr((vaddr_t)ma->ma_addr, 4))
+		return 0;
+#endif
+	return 1;
+}
+
+void
+cbus_attach(struct device *parent, struct device *self, void *args)
+{
+	struct cbus_softc *sc = (struct cbus_softc *)self;
+	struct mainbus_attach_args *ma = args;
+	struct cbus_attach_args caa;
+	int i;
+
+	for (i = 0; i < NCBUSISR; i++) {
+		sc->cbus_isr[i].isr_func = NULL;
+		/* clearing interrupt flags (INT0-INT6) */
+		*cbus_isreg = (u_int8_t)i;
+	}
+
+	/* register C-bus interrupt service routine on mainbus */
+	isrlink_autovec(cbus_intr, (void *)self, ma->ma_ilvl,
+	    ISRPRI_TTY, self->dv_xname);
+
+	printf("\n");
+
+	caa.intlevel = -1;	/* not specified */
+	config_found(self, &caa, cbus_print);
+	return;
+}
+
+int
+cbus_print(void *aux, const char *pnp)
+{
+	struct cbus_attach_args *caa = aux;
+#if 0	/* not yet */
+	if (pnp)
+		printf("%s at %s", caa->name, pnp);	/* not configured */
+#endif
+	if (caa->intlevel != -1)
+		printf(" INT %d", caa->intlevel);
+
+	return UNCONF;
+}
+
+/*
+ * Register a C-bus interrupt service routine.
+ */
+int
+cbus_isrlink(int (*func)(void *), void *arg, int ipl, const char *name)
+{
+	struct cbus_softc *sc = NULL;
+
+	if (cbus_cd.cd_ndevs != 0)
+		sc = cbus_cd.cd_devs[0];
+	if (sc == NULL)
+		panic("cbus_isrlink: can't find cbus_softc");
+
+#ifdef DIAGNOSTIC
+	if (ipl < 0 || ipl >= NCBUSISR) {
+		printf("cbus_isrlink: bad ipl %d\n", ipl);
+		return -1;
+	}
+#endif
+
+	if (sc->cbus_isr[ipl].isr_func != NULL) {
+		printf("cbus_isrlink: isr already assigned on INT%d\n", ipl);
+		return -1;
+	}
+
+	/* set the entry */
+	sc->cbus_isr[ipl].isr_func = func;
+	sc->cbus_isr[ipl].isr_arg = arg;
+	evcount_attach(&(sc->cbus_isr[ipl].isr_count), name, &ipl);
+	sc->registered |= (1 << (6 - ipl));
+#ifdef CBUS_DEBUG
+	printf("cbus_isrlink: sc->registered = 0x%02x\n", sc->registered);
+#endif
+
+	return 0;
+}
+
+/*
+ * Unregister a C-bus interrupt service routine.
+ */
+int
+cbus_isrunlink(int (*func)(void *), int ipl)
+{
+	struct cbus_softc *sc = NULL;
+
+	if (cbus_cd.cd_ndevs != 0)
+		sc = cbus_cd.cd_devs[0];
+	if (sc == NULL)
+		panic("cbus_isrunlink: can't find cbus_softc");
+
+#ifdef DIAGNOSTIC
+	if (ipl < 0 || ipl >= NCBUSISR) {
+		printf("cbus_isrunlink: bad ipl %d\n", ipl);
+		return -1;
+	}
+#endif
+
+	if (sc->cbus_isr[ipl].isr_func == NULL) {
+		printf("cbus_isrunlink: isr not assigned on INT%d\n", ipl);
+		return -1;
+	}
+
+	/* reset the entry */
+	sc->cbus_isr[ipl].isr_func = NULL;
+	sc->cbus_isr[ipl].isr_arg = NULL;
+	evcount_detach(&(sc->cbus_isr[ipl].isr_count));
+	sc->registered &= ~(1 << (6 - ipl));
+#ifdef CBUS_DEBUG
+	printf("cbus_isrunlink: sc->registered = 0x%02x\n", sc->registered);
+#endif
+
+	return 0;
+}
+
+/*
+ * Dispatch C-bus interrupt service routines.
+ */
+void
+cbus_isrdispatch(int ipl)
+{
+	int rc;
+	static int straycount, unexpected;
+	struct cbus_softc *sc = NULL;
+
+	if (cbus_cd.cd_ndevs != 0)
+		sc = cbus_cd.cd_devs[0];
+	if (sc == NULL)
+		panic("cbus_isrdispatch: can't find cbus_softc");
+
+#ifdef DIAGNOSTIC
+	if (ipl < 0 || ipl >= NCBUSISR)
+		panic("cbus_isrdispatch: bad ipl 0x%d", ipl);
+#endif
+
+	if (sc->cbus_isr[ipl].isr_func == NULL) {
+		printf("cbus_isrdispatch: ipl %d unexpected\n", ipl);
+		if (++unexpected > 10)
+			panic("too many unexpected interrupts");
+		return;
+	}
+
+	rc = sc->cbus_isr[ipl].isr_func(sc->cbus_isr[ipl].isr_arg);
+	if (rc != 0)
+		sc->cbus_isr[ipl].isr_count.ec_count++;
+
+	if (rc)
+		straycount = 0;
+	else if (++straycount > 50)
+		panic("cbus_isrdispatch: too many stray interrupts");
+	else
+		printf("cbus_isrdispatch: stray level %d interrupt\n", ipl);
+}
+
+/*
+ * Note about interrupt on PC-9801 extension board slot
+ *
+ * PC-9801 extension board slot bus (so-called 'C-bus' in Japan) use 8 own
+ * interrupt levels, INT0-INT6, and NMI.  On LUNA-88K2, they all trigger
+ * level 4 interrupt on mainbus, so we need to check the dedicated interrupt
+ * status  register to know which C-bus interrupt is occurred.
+ *
+ * The interrupt status register for C-bus is located at
+ * (u_int8_t *)CBUS_INTR_STAT. Each bit of the register becomes 0 when
+ * corresponding C-bus interrupt has occurred, otherwise 1.
+ *
+ * bit 7 = NMI(?)
+ * bit 6 = INT0
+ * bit 5 = INT1
+ *  :
+ * bit 0 = INT6
+ *
+ * To clear the C-bus interrupt flag, write the corresponding 'bit' number
+ * (as u_int_8) to the register.  For example, if you want to clear INT1,
+ * you should write '5' like:
+ *   *(u_int8_t *)CBUS_INTR_STAT = 5;
+ */
+
+/*
+ * Interrupt handler on mainbus.
+ */
+int
+cbus_intr(void *arg)
+{
+	struct cbus_softc *sc = (struct cbus_softc *)arg;
+	u_int8_t intr_status;
+	int n;
+
+	/*
+	 * LUNA-88K2's interrupt level 4 is shared with other devices,
+	 * such as le(4), for example.  So we check:
+	 * - the value of our C-bus interrupt status register, and
+	 * - if the INT level is what we are looking for.
+	 */
+	intr_status = *cbus_isreg & sc->registered;
+	if (intr_status == sc->registered) return 0;	/* Not for me */
+
+#ifdef CBUS_DEBUG
+	printf("cbus_intr: called, *cbus_isreg=0x%02x, registered = 0x%02x\n",
+	    *cbus_isreg, sc->registered);
+#endif
+	/* Make the bit pattern that we should proces */
+	intr_status = intr_status ^ sc->registered;
+#ifdef CBUS_DEBUG
+	printf("cbus_intr: processing 0x%02x\n", intr_status);
+#endif
+
+	/* Process, and clear each interrupt flag */
+	while ((n = ff1(intr_status)) != 32) {
+		cbus_isrdispatch(6 - n);
+		*cbus_isreg = (u_int8_t)n;
+		intr_status &= ~(1 << n); 
+	}
+
+	return 1;
+}
diff --git a/sys/arch/luna88k/dev/cbusvar.h b/sys/arch/luna88k/dev/cbusvar.h
new file mode 100644
index 00000000000..c73e8629223
--- /dev/null
+++ b/sys/arch/luna88k/dev/cbusvar.h
@@ -0,0 +1,46 @@
+/*	$OpenBSD: cbusvar.h,v 1.1 2014/12/08 13:24:04 aoyama Exp $	*/
+
+/*
+ * Copyright (c) 2014 Kenji Aoyama.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * PC-9801 extension board slot bus ('C-bus') driver for LUNA-88K2.
+ */
+
+#include <sys/evcount.h>
+#include <sys/queue.h>
+
+/*
+ * Currently 7 level C-bus interrupts (INT0 - INT6) are supported.
+ */
+#define NCBUSISR	7
+
+/*
+ * C-bus interrupt handler
+ */
+struct cbus_isr_t {
+	int		(*isr_func)(void *);
+	void		*isr_arg;
+	struct evcount	isr_count;
+};
+
+int	cbus_isrlink(int (*)(void *), void *, int, const char *);
+int	cbus_isrunlink(int (*)(void *), int);
+void	cbus_isrdispatch(int);
+
+struct cbus_attach_args {
+	int	intlevel;
+};
diff --git a/sys/arch/luna88k/dev/pcex.c b/sys/arch/luna88k/dev/pcex.c
index a2c825ab81c..82e8d19abac 100644
--- a/sys/arch/luna88k/dev/pcex.c
+++ b/sys/arch/luna88k/dev/pcex.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcex.c,v 1.3 2014/05/17 10:06:43 aoyama Exp $	*/
+/*	$OpenBSD: pcex.c,v 1.4 2014/12/08 13:24:04 aoyama Exp $	*/
 
 /*
  * Copyright (c) 2014 Kenji Aoyama.
@@ -25,16 +25,12 @@
 #include <sys/device.h>
 #include <sys/ioctl.h>
 
-#include <machine/asm_macro.h>	/* ff1() */
 #include <machine/autoconf.h>
 #include <machine/board.h>	/* PC_BASE */
 #include <machine/conf.h>
-#include <machine/intr.h>
 #include <machine/pcex.h>
 
-#include <uvm/uvm_extern.h>
-
-#include <luna88k/luna88k/isr.h>
+#include <luna88k/dev/cbusvar.h>
 
 extern int hz;
 
@@ -44,23 +40,6 @@ extern int hz;
 
 #define PCEXMEM_BASE	PC_BASE
 #define PCEXIO_BASE	(PC_BASE + 0x1000000)
-#define CBUS_ISR	(PC_BASE + 0x1100000)
-
-/*
- * C-bus Interrupt Status Register
- */
-volatile u_int8_t *cisr = (u_int8_t *)CBUS_ISR;
-
-const u_int8_t cisr_int_bits[] = {
-	0x40,	/* INT 0 */
-	0x20,	/* INT 1 */
-	0x10,	/* INT 2 */
-	0x08,	/* INT 3 */
-	0x04,	/* INT 4 */
-	0x02,	/* INT 5 */
-	0x01	/* INT 6 */
-/*	0x80	   NMI(?), not supported in this driver now */
-};
 
 /* autoconf stuff */
 int pcex_match(struct device *, void *, void *);
@@ -68,7 +47,7 @@ void pcex_attach(struct device *, struct device *, void *);
 
 struct pcex_softc {
 	struct device sc_dev;
-	u_int8_t int_bits;
+	int intr_use[NCBUSISR];
 };
 
 const struct cfattach pcex_ca = {
@@ -88,34 +67,20 @@ int pcex_wait_int(struct pcex_softc *, u_int);
 int
 pcex_match(struct device *parent, void *cf, void *aux)
 {
-	struct mainbus_attach_args *ma = aux;
-
-	if (strcmp(ma->ma_name, pcex_cd.cd_name))
-		return 0;
-#if 0
-	if (badaddr((vaddr_t)ma->ma_addr, 4))
-		return 0;
-#endif
-	return 1;
+	return 1;	/* XXX: always matched */
 }
 
 void
 pcex_attach(struct device *parent, struct device *self, void *args)
 {
 	struct pcex_softc *sc = (struct pcex_softc *)self;
-	struct mainbus_attach_args *ma = args;
-	u_int8_t i;
+	int i;
 
-	sc->int_bits = 0x00;
-
-	/* make sure of clearing interrupt flags for INT0-INT6 */
-	for (i = 0; i < 7; i++)
-		*cisr = i;
-
-	isrlink_autovec(pcex_intr, (void *)self, ma->ma_ilvl,
-		ISRPRI_TTY, self->dv_xname);
+	for (i = 0; i < NCBUSISR; i++)
+		sc->intr_use[i] = 0;
 
 	printf("\n");
+	return;
 }
 
 int
@@ -190,8 +155,12 @@ pcex_set_int(struct pcex_softc *sc, u_int level)
 {
 	if (level > 6)
 		return EINVAL;
+	if (sc->intr_use[level] != 0)
+		return EINVAL;	/* Duplicate */
 
-	sc->int_bits |= cisr_int_bits[level];
+	sc->intr_use[level] = 1;
+	cbus_isrlink(pcex_intr, &(sc->intr_use[level]), level,
+	    sc->sc_dev.dv_xname);
 
 	return 0;
 }
@@ -201,8 +170,11 @@ pcex_reset_int(struct pcex_softc *sc, u_int level)
 {
 	if (level > 6)
 		return EINVAL;
+	if (sc->intr_use[level] == 0)
+		return EINVAL;	/* Not registered */
 
-	sc->int_bits &= ~cisr_int_bits[level];
+	sc->intr_use[level] = 0;
+	cbus_isrunlink(pcex_intr, level);
 
 	return 0;
 }
@@ -214,74 +186,27 @@ pcex_wait_int(struct pcex_softc *sc, u_int level)
 
 	if (level > 6)
 		return EINVAL;
+	if (sc->intr_use[level] == 0)
+		return EINVAL;	/* Not registered */
+
+	ret = tsleep(&(sc->intr_use[level]), PWAIT | PCATCH, "pcex",
+	    hz /* XXX: 1 sec. */);
 
-	ret = tsleep((void *)sc, PWAIT | PCATCH, "pcex", hz /* XXX: 1 sec. */);
 #ifdef PCEX_DEBUG
 	if (ret == EWOULDBLOCK)
-		printf("%s: timeout in tsleep\n", __func__);
+		printf("pcex_wait_int: timeout in tsleep\n");
 #endif
 	return ret;
 }
 
-/*
- * Note about interrupt on PC-9801 extension board slot
- *
- * PC-9801 extension board slot bus (so-called 'C-bus' in Japan) use 8 own
- * interrupt levels, INT0-INT6, and NMI.  On LUNA-88K2, they all trigger
- * level 4 interrupt, so we need to check the dedicated interrupt status
- * register to know which C-bus interrupt is occurred.
- *
- * The interrupt status register for C-bus is located at (u_int8_t *)CBUS_ISR.
- * Each bit of the register becomes 0 when corresponding C-bus interrupt has
- * occurred, otherwise 1.
- *
- * bit 7 = NMI(?)
- * bit 6 = INT0
- * bit 5 = INT1
- *  :
- * bit 0 = INT6
- *
- * To clear the C-bus interrupt flag, write the corresponding 'bit' number
- * (as u_int_8) to the register.  For example, if you want to clear INT1,
- * you should write '5' like:
- *   *(u_int8_t *)CBUS_ISR = 5;
- */
-
-/*
- * Interrupt handler
- */
 int
 pcex_intr(void *arg)
 {
-	struct pcex_softc *sc = (struct pcex_softc *)arg;
-	u_int8_t int_status;
-	int n;
-
-	/*
-	 * LUNA-88K2's interrupt level 4 is shared with other devices,
-	 * such as le(4), for example.  So we check:
-	 * - the value of our C-bus interrupt status register, and
-	 * - if the INT level is what we are looking for.
-	 */
-	int_status = *cisr & sc->int_bits;
-	if (int_status == sc->int_bits) return 0;	/* Not for me */
-
 #ifdef PCEX_DEBUG
-	printf("%s: called, *cisr=0x%02x, int_bits = 0x%02x\n",
-		__func__, *cisr, sc->int_bits);
+	printf("pcex_intr: called, arg=%p\n", arg);
 #endif
-
 	/* Just wakeup(9) for now */
-	wakeup((void *)sc);
-
-	/* Make the bit pattern that we should clear interrupt flag */
-	int_status = int_status ^ sc->int_bits;
-
-	/* Clear each interrupt flag */
-	while ((n = ff1(int_status)) != 32) {
-		*cisr = (u_int8_t)n;
-		int_status &= ~(1 << n); 
-	}
+	wakeup(arg);
 
 	return 1;
 }
diff --git a/sys/arch/luna88k/luna88k/mainbus.c b/sys/arch/luna88k/luna88k/mainbus.c
index da163a051e1..30a17e7b90a 100644
--- a/sys/arch/luna88k/luna88k/mainbus.c
+++ b/sys/arch/luna88k/luna88k/mainbus.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mainbus.c,v 1.11 2014/05/08 13:31:00 aoyama Exp $ */
+/* $OpenBSD: mainbus.c,v 1.12 2014/12/08 13:24:04 aoyama Exp $ */
 /* $NetBSD: mainbus.c,v 1.2 2000/01/07 05:13:08 nisimura Exp $ */
 
 /*-
@@ -54,12 +54,7 @@ static const struct mainbus_attach_args devs[] = {
 	{ "fb",	   0xc1100000, -1, LUNA_88K|LUNA_88K2 }, /* BrookTree RAMDAC */
 	{ "spc",   0xe1000000, 3,  LUNA_88K|LUNA_88K2 }, /* MB89352 */
 	{ "spc",   0xe1000040, 3,  LUNA_88K2 },          /* ditto, LUNA-88K2 only */
-#if NPCM > 0
-	{ "pcm",   0x91000000, 4,  LUNA_88K2 }, 	 /* NEC-9801-86 Sound board (under testing) */
-#endif
-#if NPCEX > 0
-	{ "pcex",  0x91000000, 4,  LUNA_88K2 },		 /* PC-9801 extension slot */
-#endif
+	{ "cbus",  0x91000000, 4,  LUNA_88K2 },		 /* PC-9801 extension slot */
 };
 
 void	mainbus_attach(struct device *, struct device *, void *);