libtopo/common/topo_tree.c

/*
 * 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 (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * Topology Trees
 *
 * Toplogy trees are instantiated for each builtin (FMRI) scheme specified
 * in topo_builtin.c.  Each ttree_t data structure contains the
 * skeleton of the topology tree (scheme, root node, and file information).
 * The root node of a topology does not represent any FMRI but rather serves
 * as the entry point for topology access interfaces.  The file information
 * provides a handle to access static .xml files that seed scheme-specifc
 * topologies
 *
 * Topology trees will remain unpopulated until topo_snap_hold() is called.
 * At that time, a ttree_t structure is allocated and added to the list
 * trees maintained in topo_hdl_t.  Builtin scheme-specific enumerators are
 * called upon to create nodes that represent FMRIs for resources present in the
 * system.  If a <scheme>-topology.xml file exists in a standard file
 * location, the file is used to seed the topology while the rest is
 * dynamically created by the builtin or helper enumerator modules.
 * For example, the 'hc' tree is enumerated by the hc enumerator (hc.c)
 * after the hc-topology.xml is read from /usr/platform/`uname -i`/lib/fm/topo,
 * /usr/platform/`uname -r`/lib/fm/topo, or /usr/lib/fm/topo.  Each node
 * is created with a properly formatted hc FMRI resource.
 *
 * Toplogy trees are released and deallocated when topo_snap_hold is called.
 * Upon return from topo_snap_rele(), all node resources are deallocated
 * and all that remains is the ttree_t structure containing the root node.
 */

#include <pthread.h>
#include <limits.h>
#include <assert.h>
#include <sys/param.h>
#include <sys/systeminfo.h>
#include <sys/utsname.h>

#include <topo_alloc.h>
#include <topo_error.h>
#include <topo_file.h>
#include <topo_module.h>
#include <topo_string.h>
#include <topo_subr.h>
#include <topo_tree.h>

static ttree_t *
set_create_error(topo_hdl_t *thp, ttree_t *tp, int err)
{
    if (tp != NULL)
        topo_tree_destroy(tp);

    if (err != 0)
        (void) topo_hdl_seterrno(thp, err);

    return (NULL);
}

ttree_t *
topo_tree_create(topo_hdl_t *thp, topo_mod_t *mod, const char *scheme)
{
    ttree_t *tp;
    tnode_t *rp;

    if ((tp = topo_mod_zalloc(mod, sizeof (ttree_t))) == NULL)
        return (set_create_error(thp, NULL, ETOPO_NOMEM));

    tp->tt_mod = mod;

    if ((tp->tt_scheme = topo_mod_strdup(mod, scheme)) == NULL)
        return (set_create_error(thp, tp, ETOPO_NOMEM));

    /*
     * Initialize a private walker for internal use
     */
    if ((tp->tt_walk = topo_mod_zalloc(mod, sizeof (topo_walk_t))) == NULL)
        return (set_create_error(thp, tp, ETOPO_NOMEM));

    /*
     * Create the root of this tree: LINKED but never BOUND
     */
    if ((rp = topo_mod_zalloc(mod, sizeof (tnode_t))) == NULL)
        return (set_create_error(thp, tp, 0)); /* th_errno set */

    rp->tn_state = TOPO_NODE_ROOT | TOPO_NODE_INIT;
    rp->tn_name = tp->tt_scheme;
    rp->tn_instance = 0;
    rp->tn_enum = mod;
    rp->tn_hdl = thp;

    topo_node_hold(rp);

    tp->tt_walk->tw_root = rp;
    tp->tt_walk->tw_thp = thp;

    topo_mod_hold(mod); /* released when root node destroyed */

    tp->tt_root = rp;

    return (tp);
}

void
topo_tree_destroy(ttree_t *tp)
{
    topo_mod_t *mod;

    if (tp == NULL)
        return;

    mod = tp->tt_mod;
    if (tp->tt_walk != NULL)
        topo_mod_free(mod, tp->tt_walk, sizeof (topo_walk_t));

    if (tp->tt_root != NULL) {
        assert(tp->tt_root->tn_refs == 1);
        topo_node_rele(tp->tt_root);
    }
    /*
     * Deallocate this last, because a pointer alias for tt_scheme
     * (stored in the root node's name field) may be used in
     * topo_node_rele().
     */
    if (tp->tt_scheme != NULL)
        topo_mod_strfree(mod, tp->tt_scheme);

    topo_mod_free(mod, tp, sizeof (ttree_t));
}

static int
topo_tree_enum(topo_hdl_t *thp, ttree_t *tp)
{
    int rv = 0;
    char *pp;
    boolean_t load_snapshot;

    load_snapshot = ((thp->th_snap_dir == NULL) ? B_FALSE : B_TRUE);

    topo_dprintf(thp, TOPO_DBG_SNAP, "%s: scheme=%s, load_snapshot=%s\n",
        __func__, tp->tt_scheme,
        (load_snapshot == B_TRUE) ? "TRUE" : "FALSE");

    if (load_snapshot == B_TRUE) {
        /*
         * Enumerate by loading in a saved topology snapshot.
         */
        rv = topo_file_load(tp->tt_root->tn_enum, tp->tt_root,
            NULL, tp->tt_scheme, B_FALSE);
    } else {
        /*
         * Attempt to enumerate the tree from a topology map in the
         * following order:
         *  <product-name>-<scheme>-topology
         *  <platform-name>-<scheme>-topology (uname -i)
         *  <machine-name>-<scheme>-topology (uname -m)
         *  <scheme>-topology
         *
         * Trim any SUNW, from the product or platform name
         * before loading file
         */
        if (thp->th_product == NULL ||
            (pp = strchr(thp->th_product, ',')) == NULL)
            pp = thp->th_product;
        else
            pp++;
        if (topo_file_load(tp->tt_root->tn_enum, tp->tt_root,
            pp, tp->tt_scheme, B_FALSE) < 0) {
            if ((pp = strchr(thp->th_platform, ',')) == NULL)
                pp = thp->th_platform;
            else
                pp++;
            if (topo_file_load(tp->tt_root->tn_enum, tp->tt_root,
                pp, tp->tt_scheme, B_FALSE) < 0) {
                if (topo_file_load(tp->tt_root->tn_enum,
                    tp->tt_root, thp->th_machine,
                    tp->tt_scheme, B_FALSE) < 0) {
                    rv = topo_file_load(
                        tp->tt_root->tn_enum, tp->tt_root,
                        NULL, tp->tt_scheme, B_FALSE);
                }
            }
        }
    }

    if (rv != 0) {
        topo_dprintf(thp, TOPO_DBG_ERR, "%s: failed to load topology "
            "map for %s FMRI scheme, errmsg=%s\n", __func__,
            tp->tt_scheme, topo_mod_errmsg(tp->tt_root->tn_enum));
        return (topo_hdl_seterrno(thp,
            topo_mod_errno(tp->tt_root->tn_enum)));
    }

    return (0);
}

int
topo_tree_enum_all(topo_hdl_t *thp)
{
    int err = 0;
    ttree_t *tp;

    for (tp = topo_list_next(&thp->th_trees); tp != NULL;
        tp = topo_list_next(tp)) {
        if (topo_tree_enum(thp, tp) < 0) {
            err++;
            if ((topo_hdl_errno(thp) == ETOPO_ENUM_FATAL))
                break;
        }
    }

    if (err != 0)
        return (-1);
    else
        return (0);
}