linux/drivers/pci/of.c
David Daney 69566dd8be PCI: OF: Don't crash when bridge parent is NULL.
In pcibios_get_phb_of_node(), we will crash while booting if
bus->bridge->parent is NULL.

Check for this case and avoid dereferencing the NULL pointer.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-08-19 08:51:37 -07:00

61 lines
1.5 KiB
C

/*
* PCI <-> OF mapping helpers
*
* Copyright 2011 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/of.h>
#include <linux/of_pci.h>
#include "pci.h"
void pci_set_of_node(struct pci_dev *dev)
{
if (!dev->bus->dev.of_node)
return;
dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
dev->devfn);
}
void pci_release_of_node(struct pci_dev *dev)
{
of_node_put(dev->dev.of_node);
dev->dev.of_node = NULL;
}
void pci_set_bus_of_node(struct pci_bus *bus)
{
if (bus->self == NULL)
bus->dev.of_node = pcibios_get_phb_of_node(bus);
else
bus->dev.of_node = of_node_get(bus->self->dev.of_node);
}
void pci_release_bus_of_node(struct pci_bus *bus)
{
of_node_put(bus->dev.of_node);
bus->dev.of_node = NULL;
}
struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
{
/* This should only be called for PHBs */
if (WARN_ON(bus->self || bus->parent))
return NULL;
/* Look for a node pointer in either the intermediary device we
* create above the root bus or it's own parent. Normally only
* the later is populated.
*/
if (bus->bridge->of_node)
return of_node_get(bus->bridge->of_node);
if (bus->bridge->parent && bus->bridge->parent->of_node)
return of_node_get(bus->bridge->parent->of_node);
return NULL;
}