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/*
* Copyright (c) 2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <ofw_tree.h>
#include <ofw.h>
#include <types.h>
#include <string.h>
#include <balloc.h>
#include <asm.h>
#define MAX_PATH_LEN 256
static ofw_tree_node_t *ofw_tree_node_alloc(void)
{
return balloc(sizeof(ofw_tree_node_t), sizeof(ofw_tree_node_t));
}
static ofw_tree_property_t *ofw_tree_properties_alloc(unsigned count)
{
return balloc(count * sizeof(ofw_tree_property_t), sizeof(ofw_tree_property_t));
}
static void * ofw_tree_space_alloc(size_t size)
{
char *addr;
/*
* What we do here is a nasty hack :-)
* Problem: string property values that are allocated via this
* function typically do not contain the trailing '\0'. This
* is very uncomfortable for kernel, which is supposed to deal
* with the properties.
* Solution: when allocating space via this function, we always
* allocate space for the extra '\0' character that we store
* behind the requested memory.
*/
addr = balloc(size + 1, size);
if (addr)
addr[size] = '\0';
return addr;
}
/** Transfer information from one OpenFirmware node into its memory representation.
*
* Transfer entire information from the OpenFirmware device tree 'current' node to
* its memory representation in 'current_node'. This function recursively processes
* all node's children. Node's peers are processed iteratively in order to prevent
* stack from overflowing.
*
* @param current_node Pointer to uninitialized ofw_tree_node structure that will
* become the memory represenation of 'current'.
* @param parent_node Parent ofw_tree_node structure or NULL in case of root node.
* @param current OpenFirmware phandle to the current device tree node.
*/
static void ofw_tree_node_process(ofw_tree_node_t *current_node,
ofw_tree_node_t *parent_node, phandle current)
{
static char path[MAX_PATH_LEN+1];
static char name[OFW_TREE_PROPERTY_MAX_NAMELEN];
phandle peer;
phandle child;
size_t len;
int i;
while (current_node) {
/*
* Initialize node.
*/
current_node->parent = parent_node;
current_node->peer = NULL;
current_node->child = NULL;
current_node->node_handle = current;
current_node->properties = 0;
current_node->property = NULL;
current_node->device = NULL;
/*
* Get the disambigued name.
*/
len = ofw_package_to_path(current, path, MAX_PATH_LEN);
if (len == -1)
return;
path[len] = '\0';
for (i = len - 1; i >= 0 && path[i] != '/'; i--)
;
i++; /* do not include '/' */
len -= i;
/* add space for trailing '\0' */
current_node->da_name = ofw_tree_space_alloc(len + 1);
if (!current_node->da_name)
return;
memcpy(current_node->da_name, &path[i], len);
current_node->da_name[len] = '\0';
/*
* Recursively process the potential child node.
*/
child = ofw_get_child_node(current);
if (child != 0 && child != -1) {
ofw_tree_node_t *child_node;
child_node = ofw_tree_node_alloc();
if (child_node) {
ofw_tree_node_process(child_node, current_node, child);
current_node->child = child_node;
}
}
/*
* Count properties.
*/
name[0] = '\0';
while (ofw_next_property(current, name, name) == 1)
current_node->properties++;
if (!current_node->properties)
return;
/*
* Copy properties.
*/
current_node->property = ofw_tree_properties_alloc(current_node->properties);
if (!current_node->property)
return;
name[0] = '\0';
for (i = 0; ofw_next_property(current, name, name) == 1; i++) {
size_t size;
if (i == current_node->properties)
break;
memcpy(current_node->property[i].name, name,
OFW_TREE_PROPERTY_MAX_NAMELEN);
current_node->property[i].name[OFW_TREE_PROPERTY_MAX_NAMELEN] = '\0';
size = ofw_get_proplen(current, name);
current_node->property[i].size = size;
if (size) {
void *buf;
buf = ofw_tree_space_alloc(size);
if (current_node->property[i].value = buf) {
/*
* Copy property value to memory node.
*/
(void) ofw_get_property(current, name, buf, size);
}
} else {
current_node->property[i].value = NULL;
}
}
current_node->properties = i; /* Just in case we ran out of memory. */
/*
* Iteratively process the next peer node.
* Note that recursion is a bad idea here.
* Due to the topology of the OpenFirmware device tree,
* the nesting of peer nodes could be to wide and the
* risk of overflowing the stack is too real.
*/
peer = ofw_get_peer_node(current);
if (peer != 0 && peer != -1) {
ofw_tree_node_t *peer_node;
peer_node = ofw_tree_node_alloc();
if (peer_node) {
current_node->peer = peer_node;
current_node = peer_node;
current = peer;
/*
* Process the peer in next iteration.
*/
continue;
}
}
/*
* No more peers on this level.
*/
break;
}
}
/** Construct memory representation of OpenFirmware device tree.
*
* @return NULL on failure or pointer to the root node.
*/
ofw_tree_node_t *ofw_tree_build(void)
{
ofw_tree_node_t *root;
phandle ssm_node;
ofw_tree_node_t *ssm;
root = ofw_tree_node_alloc();
if (root)
ofw_tree_node_process(root, NULL, ofw_root);
/*
* The firmware client interface does not automatically include the
* "ssm" node in the list of children of "/". A nasty yet working
* solution is to explicitly stick "ssm" to the OFW tree.
*/
ssm_node = ofw_find_device("/ssm@0,0");
if (ssm_node != -1) {
ssm = ofw_tree_node_alloc();
if (ssm) {
ofw_tree_node_process(
ssm, root, ofw_find_device("/ssm@0,0"));
ssm->peer = root->child;
root->child = ssm;
}
}
return root;
}