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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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69566dd8be
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>
62 lines
1.5 KiB
C
62 lines
1.5 KiB
C
/*
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* PCI <-> OF mapping helpers
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*
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* Copyright 2011 IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <linux/of.h>
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#include <linux/of_pci.h>
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#include "pci.h"
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void pci_set_of_node(struct pci_dev *dev)
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{
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if (!dev->bus->dev.of_node)
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return;
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dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
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dev->devfn);
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}
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void pci_release_of_node(struct pci_dev *dev)
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{
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of_node_put(dev->dev.of_node);
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dev->dev.of_node = NULL;
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}
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void pci_set_bus_of_node(struct pci_bus *bus)
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{
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if (bus->self == NULL)
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bus->dev.of_node = pcibios_get_phb_of_node(bus);
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else
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bus->dev.of_node = of_node_get(bus->self->dev.of_node);
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}
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void pci_release_bus_of_node(struct pci_bus *bus)
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{
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of_node_put(bus->dev.of_node);
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bus->dev.of_node = NULL;
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}
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struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
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{
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/* This should only be called for PHBs */
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if (WARN_ON(bus->self || bus->parent))
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return NULL;
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/* Look for a node pointer in either the intermediary device we
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* create above the root bus or it's own parent. Normally only
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* the later is populated.
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*/
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if (bus->bridge->of_node)
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return of_node_get(bus->bridge->of_node);
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if (bus->bridge->parent && bus->bridge->parent->of_node)
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return of_node_get(bus->bridge->parent->of_node);
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return NULL;
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}
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