1 files changed, 180 insertions, 0 deletions
diff --git a/usr/src/uts/common/io/nulldriver.c b/usr/src/uts/common/io/nulldriver.c
new file mode 100644
index 0000000000..04e8d86b22
--- /dev/null
+++ b/usr/src/uts/common/io/nulldriver.c
@@ -0,0 +1,180 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*
+ * nulldriver - null device driver
+ *
+ * The nulldriver is used to associate a solaris driver with a specific
+ * device without enabling external device access.
+ *
+ * The driver can be used to:
+ *
+ * o Prevent external access to specific devices/hardware by associating a
+ *   high-precedence 'compatible' binding, including a path-oriented alias,
+ *   with nulldriver.
+ *
+ * o Enable a nexus bus_config implementation to perform dynamic child
+ *   discovery by creating a child 'probe' devinfo node, bound to
+ *   nulldriver, at the specific child @unit-addresses associated with
+ *   discovery.  With a nulldriver bound 'probe' node, nexus driver
+ *   bus_config discovery code can use the same devinfo node oriented
+ *   transport services for both discovery and normal-operation: which
+ *   is a significant simplification.  While nulldriver prevents external
+ *   device access, a nexus driver can still internally use the transport
+ *   services.
+ *
+ *   A scsi(4) example of this type of use is SCSA enumeration services
+ *   issuing a scsi REPORT_LUN command to a lun-0 'probe' node bound to
+ *   nulldriver in order to discover all luns supported by a target.
+ */
+
+#include <sys/modctl.h>
+#include <sys/conf.h>
+#include <sys/ddi.h>
+#include <sys/sunddi.h>
+#include <sys/cmn_err.h>
+
+static int nulldriver_getinfo(dev_info_t *, ddi_info_cmd_t, void *, void **);
+static int nulldriver_probe(dev_info_t *);
+static int nulldriver_attach(dev_info_t *, ddi_attach_cmd_t);
+static int nulldriver_detach(dev_info_t *, ddi_detach_cmd_t);
+
+static struct cb_ops nulldriver_cb_ops = {
+	nodev,				/* open */
+	nodev,				/* close */
+	nodev,				/* strategy */
+	nodev,				/* print */
+	nodev,				/* dump */
+	nodev,				/* read */
+	nodev,				/* write */
+	nodev,				/* ioctl */
+	nodev,				/* devmap */
+	nodev,				/* mmap */
+	nodev,				/* segmap */
+	nochpoll,			/* poll */
+	ddi_prop_op,			/* cb_prop_op */
+	0,				/* streamtab  */
+	D_MP | D_NEW | D_HOTPLUG	/* Driver compatibility flag */
+};
+
+static struct dev_ops nulldriver_dev_ops = {
+	DEVO_REV,			/* devo_rev, */
+	0,				/* refcnt  */
+	nulldriver_getinfo,		/* info */
+	nodev,				/* identify */
+	nulldriver_probe,		/* probe */
+	nulldriver_attach,		/* attach */
+	nulldriver_detach,		/* detach */
+	nodev,				/* reset */
+	&nulldriver_cb_ops,		/* driver operations */
+	(struct bus_ops *)0,		/* bus operations */
+	NULL,				/* power */
+	ddi_quiesce_not_needed,		/* quiesce */
+};
+
+static struct modldrv modldrv = {
+	&mod_driverops, "nulldriver 1.1", &nulldriver_dev_ops
+};
+
+static struct modlinkage modlinkage = {
+	MODREV_1, &modldrv, NULL
+};
+
+int
+_init(void)
+{
+	return (mod_install(&modlinkage));
+}
+
+int
+_fini(void)
+{
+	return (mod_remove(&modlinkage));
+}
+
+int
+_info(struct modinfo *modinfop)
+{
+	return (mod_info(&modlinkage, modinfop));
+}
+
+/*ARGSUSED*/
+static int
+nulldriver_getinfo(dev_info_t *dip, ddi_info_cmd_t infocmd,
+    void *arg, void **result)
+{
+	return (DDI_FAILURE);
+}
+
+/*ARGSUSED*/
+static int
+nulldriver_probe(dev_info_t *dip)
+{
+	/*
+	 * We want to succeed probe so that the node gets assigned a unit
+	 * address "@addr".
+	 */
+	if (ddi_dev_is_sid(dip) == DDI_SUCCESS)
+		return (DDI_PROBE_DONTCARE);
+	return (DDI_PROBE_DONTCARE);
+}
+
+/*
+ * nulldriver_attach()
+ *	attach(9e) entrypoint.
+ */
+/* ARGSUSED */
+static int
+nulldriver_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
+{
+	switch (cmd) {
+	case DDI_ATTACH:
+	case DDI_RESUME:
+		return (DDI_SUCCESS);
+
+	case DDI_PM_RESUME:
+	default:
+		return (DDI_FAILURE);
+	}
+}
+
+/*
+ * nulldriver_detach()
+ *	detach(9E) entrypoint
+ */
+/* ARGSUSED */
+static int
+nulldriver_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
+{
+	switch (cmd) {
+	case DDI_DETACH:
+	case DDI_SUSPEND:
+		return (DDI_SUCCESS);
+
+	case DDI_PM_SUSPEND:
+	default:
+		return (DDI_FAILURE);
+	}
+}