/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 *

 * 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 2006 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*

 * Topology Nodes

 *

 * Topology nodes, tnode_t, are data structures containing per-FMRI

 * information and are linked together to form the topology tree.

 * Nodes are created during the enumeration process of topo_snap_hold()

 * and destroyed during topo_snap_rele().  For the most part, tnode_t data

 * is read-only and no lock protection is required.  Nodes are

 * held in place during tree walk functions.  Tree walk functions

 * may access node data safely without locks.  The exception to this rule

 * is data associated with node properties (topo_prop.c).  Properties

 * may change at anytime and are protected by a per-property locking

 * strategy.

 *

 * Enumerator plugin modules may also safely access node data.  Enumeration

 * occurs only during topo_snap_hold() where a per-topo_hdl_t lock prevents

 * multi-threaded access to the topology trees.

 *

 * Like tree walking functions, method plugin modules have access to read-only

 * node data but may make changes to property information.

 *

 * Node Interfaces

 *

 * Nodes are created when an enumerator calls topo_node_bind().  Prior to the

 * call to topo_node_bind(), the caller should have reserved a range of

 * node instances with topo_node_range_create().  topo_node_range_create()

 * does not allocate any node resources but creates the infrastruture

 * required for a fully populated topology level.  This allows enumerators

 * reading from a <scheme>-topology.xml file to parse the file for a range

 * of resources before confirming the existence of a resource via a helper

 * plugin.  Only when the resource has been confirmed to exist should

 * the node be bound.

 *

 * Node range and node linkage is only performed during enumeration when it

 * is safe to change node hash lists and next pointers. Nodes and node ranges

 * are deallocated when all references to the node have been released:

 * last walk completes and topo_snap_rele() is called.

 *

 * Node Hash/Ranges

 *

 * Each parent node may have one or more ranges of child nodes.  Each range

 * serves as a hash list of like sibling nodes all with the same name but

 * different instance numbers.  A parent may have more than one node hash

 * (child range). If that is the case, the hash lists are strung together to

 * form sibling relationships between ranges.  Hash/Ranges are sparsely

 * populated with only nodes that have represented resources in the system.

 */

#include <assert.h>

#include <pthread.h>

#include <strings.h>

#include <topo_alloc.h>

#include <topo_tree.h>

static void

topo_node_destroy(tnode_t *node)

{

	int i;

	tnode_t *pnode = node->tn_parent;

	topo_nodehash_t *nhp;

	topo_mod_t *hmod, *mod = node->tn_enum;

	if (node == NULL)

		return;

	assert(node->tn_refs == 0);

	/*

	 * If not a root node, remove this node from the parent's node hash

	 */

	if (!(node->tn_state & TOPO_NODE_ROOT)) {

		topo_node_lock(pnode);

		nhp = node->tn_phash;

		for (i = 0; i < nhp->th_arrlen; i++) {

			if (node == nhp->th_nodearr[i]) {

				nhp->th_nodearr[i] = NULL;

				/*

				 * Release hold on parent

				 */

				--pnode->tn_refs;

				if (pnode->tn_refs == 0)

					topo_node_destroy(pnode);

			}

		}

		topo_node_unlock(pnode);

	}

	topo_node_unlock(node);

	/*

	 * Allow enumerator to clean-up private data and then release

	 * ref count

	 */

	topo_method_unregister_all(mod, node);

	/*

	 * Destroy all node hash lists

	 */

	while ((nhp = topo_list_next(&node->tn_children)) != NULL) {

		for (i = 0; i < nhp->th_arrlen; i++) {

			assert(nhp->th_nodearr[i] == NULL);

		}

		hmod = nhp->th_enum;

		topo_mod_strfree(hmod, nhp->th_name);

		topo_mod_free(hmod, nhp->th_nodearr,

		    nhp->th_arrlen * sizeof (tnode_t *));

		topo_list_delete(&node->tn_children, nhp);

		topo_mod_free(hmod, nhp, sizeof (topo_nodehash_t));

		topo_mod_rele(hmod);

	}

	/*

	 * Destroy all property data structures, free the node and release

	 * the module that created it

	 */

	topo_pgroup_destroy_all(node);

	topo_mod_free(mod, node, sizeof (tnode_t));

	topo_mod_rele(mod);

}

void

topo_node_lock(tnode_t *node)

{

	(void) pthread_mutex_lock(&node->tn_lock);

}

void

topo_node_unlock(tnode_t *node)

{

	(void) pthread_mutex_unlock(&node->tn_lock);

}

void

topo_node_hold(tnode_t *node)

{

	topo_node_lock(node);

	++node->tn_refs;

	topo_node_unlock(node);

}

void

topo_node_rele(tnode_t *node)

{

	topo_node_lock(node);

	--node->tn_refs;

	/*

	 * Ok to remove this node from the topo tree and destroy it

	 */

	if (node->tn_refs == 0)

		topo_node_destroy(node);

	else

		topo_node_unlock(node);

}

char *

topo_node_name(tnode_t *node)

{

	return (node->tn_name);

}

topo_instance_t

topo_node_instance(tnode_t *node)

{

	return (node->tn_instance);

}

void *

{

	return (node->tn_priv);

}

static int

node_create_seterror(topo_mod_t *mod, tnode_t *pnode, topo_nodehash_t *nhp,

    int err)

{

	topo_node_unlock(pnode);

	    "%s\n", topo_strerror(err));

	if (nhp != NULL) {

		if (nhp->th_name != NULL)

			topo_mod_strfree(mod, nhp->th_name);

		if (nhp->th_nodearr != NULL) {

			topo_mod_free(mod, nhp->th_nodearr,

			    nhp->th_arrlen * sizeof (tnode_t *));

		}

		topo_mod_free(mod, nhp, sizeof (topo_nodehash_t));

	}

	return (topo_mod_seterrno(mod, err));

}

int

topo_node_range_create(topo_mod_t *mod, tnode_t *pnode, const char *name,

    topo_instance_t min, topo_instance_t max)

{

	topo_nodehash_t *nhp;

	topo_node_lock(pnode);

	assert((pnode->tn_state & TOPO_NODE_BOUND) ||

	    (pnode->tn_state & TOPO_NODE_ROOT));

	for (nhp = topo_list_next(&pnode->tn_children); nhp != NULL;

	    nhp = topo_list_next(nhp)) {

		if (strcmp(nhp->th_name, name) == 0)

			return (node_create_seterror(mod, pnode, NULL,

			    ETOPO_NODE_DUP));

	}

	if (min < 0 || max < min)

		return (node_create_seterror(mod, pnode, NULL,

		    ETOPO_NODE_INVAL));

	if ((nhp = topo_mod_zalloc(mod, sizeof (topo_nodehash_t))) == NULL)

		return (node_create_seterror(mod, pnode, nhp, ETOPO_NOMEM));

	if ((nhp->th_name = topo_mod_strdup(mod, name)) == NULL)

		return (node_create_seterror(mod, pnode, nhp, ETOPO_NOMEM));

	nhp->th_arrlen = max - min + 1;

	if ((nhp->th_nodearr = topo_mod_zalloc(mod,

	    nhp->th_arrlen * sizeof (tnode_t *))) == NULL)

		return (node_create_seterror(mod, pnode, nhp, ETOPO_NOMEM));

	nhp->th_range.tr_min = min;

	nhp->th_range.tr_max = max;

	nhp->th_enum = mod;

	topo_mod_hold(mod);

	/*

	 * Add these nodes to parent child list

	 */

	topo_list_append(&pnode->tn_children, nhp);

	topo_node_unlock(pnode);

	return (0);

}

void

topo_node_range_destroy(tnode_t *pnode, const char *name)

{

	int i;

	topo_nodehash_t *nhp;

	topo_mod_t *mod;

	topo_node_lock(pnode);

	for (nhp = topo_list_next(&pnode->tn_children); nhp != NULL;

	    nhp = topo_list_next(nhp)) {

		if (strcmp(nhp->th_name, name) == 0) {

			break;

		}

	}

	if (nhp == NULL) {

		topo_node_unlock(pnode);

		return;

	}

	topo_list_delete(&pnode->tn_children, nhp);

	topo_node_unlock(pnode);

	/*

	 * Should be an empty node range

	 */

	for (i = 0; i < nhp->th_arrlen; i++) {

		topo_node_unbind(nhp->th_nodearr[i]);

	}

	mod = nhp->th_enum;

	if (nhp->th_name != NULL)

		topo_mod_strfree(mod, nhp->th_name);

	if (nhp->th_nodearr != NULL) {

		topo_mod_free(mod, nhp->th_nodearr,

		    nhp->th_arrlen * sizeof (tnode_t *));

	}

	topo_mod_free(mod, nhp, sizeof (topo_nodehash_t));

	topo_mod_rele(mod);

}

tnode_t *

topo_node_lookup(tnode_t *pnode, const char *name, topo_instance_t inst)

{

	int h;

	tnode_t *node;

	topo_nodehash_t *nhp;

	topo_node_lock(pnode);

	for (nhp = topo_list_next(&pnode->tn_children); nhp != NULL;

	    nhp = topo_list_next(nhp)) {

		if (strcmp(nhp->th_name, name) == 0) {

			if (inst > nhp->th_range.tr_max ||

			    inst < nhp->th_range.tr_min) {

				topo_node_unlock(pnode);

				return (NULL);

			}

			h = topo_node_hash(nhp, inst);

			node = nhp->th_nodearr[h];

			topo_node_unlock(pnode);

			return (node);

		}

	}

	topo_node_unlock(pnode);

	return (NULL);

}

int

topo_node_hash(topo_nodehash_t *nhp, topo_instance_t inst)

{

	return (nhp->th_range.tr_max == 0 ?

	    nhp->th_range.tr_max : inst % (nhp->th_range.tr_max + 1));

}

static tnode_t *

node_bind_seterror(topo_mod_t *mod, tnode_t *pnode, tnode_t *node, int err)

{

	topo_node_unlock(pnode);

	(void) topo_mod_seterrno(mod, err);

	if (node == NULL)

		return (NULL);

	    "%s\n", (node->tn_name != NULL ? node->tn_name : "unknown"),

	    node->tn_instance, topo_strerror(err));

	topo_node_lock(node); /* expected to be locked */

	topo_node_destroy(node);

	return (NULL);

}

tnode_t *

topo_node_bind(topo_mod_t *mod, tnode_t *pnode, const char *name,

{

	int h, err;

	tnode_t *node;

	topo_nodehash_t *nhp;

	topo_node_lock(pnode);

	for (nhp = topo_list_next(&pnode->tn_children); nhp != NULL;

	    nhp = topo_list_next(nhp)) {

		if (strcmp(nhp->th_name, name) == 0) {

			if (inst > nhp->th_range.tr_max ||

			    inst < nhp->th_range.tr_min)

				return (node_bind_seterror(mod, pnode, NULL,

				    ETOPO_NODE_INVAL));

			h = topo_node_hash(nhp, inst);

			if (nhp->th_nodearr[h] != NULL)

				return (node_bind_seterror(mod, pnode, NULL,

				    ETOPO_NODE_BOUND));

			else

				break;

		}

	}

	if (nhp == NULL)

		return (node_bind_seterror(mod, pnode, NULL, ETOPO_NODE_NOENT));

	if ((node = topo_mod_zalloc(mod, sizeof (tnode_t))) == NULL)

		return (node_bind_seterror(mod, pnode, NULL, ETOPO_NOMEM));

	(void) pthread_mutex_init(&node->tn_lock, NULL);

	node->tn_enum = mod;

	node->tn_hdl = mod->tm_hdl;

	node->tn_parent = pnode;

	node->tn_name = nhp->th_name;

	node->tn_instance = inst;

	node->tn_phash = nhp;

	node->tn_refs = 0;

	/* Ref count module that bound this node */

	topo_mod_hold(mod);

	if (fmri == NULL)

		return (node_bind_seterror(mod, pnode, node, ETOPO_NODE_INVAL));

		return (node_bind_seterror(mod, pnode, node, err));

	if (topo_prop_set_fmri(node, TOPO_PGROUP_PROTOCOL, TOPO_PROP_RESOURCE,

		return (node_bind_seterror(mod, pnode, node, err));

	node->tn_state |= TOPO_NODE_BOUND;

	topo_node_hold(node);

	nhp->th_nodearr[h] = node;

	++pnode->tn_refs;

	topo_node_unlock(pnode);

	}

	return (node);

}

void

topo_node_unbind(tnode_t *node)

{

	if (node == NULL)

		return;

	topo_node_lock(node);

	if (!(node->tn_state & TOPO_NODE_BOUND)) {

		topo_node_unlock(node);

		return;

	}

	node->tn_state &= ~TOPO_NODE_BOUND;

	topo_node_unlock(node);

	topo_node_rele(node);

}

/*ARGSUSED*/

int

topo_node_present(tnode_t *node)

{

	return (0);

}

/*ARGSUSED*/

int

topo_node_contains(tnode_t *er, tnode_t *ee)

{

	return (0);

}

/*ARGSUSED*/

int

topo_node_unusable(tnode_t *node)

{

	return (0);

}