linux_dsm_epyc7002/arch/powerpc/kernel/of_platform.c
Thadeu Lima de Souza Cascardo 6a040ce725 powerpc/eeh: Fix crash when adding a device in a slot with DDW
The DDW code uses a eeh_dev struct from the pci_dev. However, this is
not set until eeh_add_device_late is called.

Since pci_bus_add_devices is called before eeh_add_device_late, the PCI
devices are added to the bus, making drivers' probe hooks to be called.
These will call set_dma_mask, which will call the DDW code, which will
require the eeh_dev struct from pci_dev. This would result in a crash,
due to a NULL dereference.

Calling eeh_add_device_late after pci_bus_add_devices would make the
system BUG, because device files shouldn't be added to devices there
were not added to the system. So, a new function is needed to add such
files only after pci_bus_add_devices have been called.

Cc: stable@vger.kernel.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Acked-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10 17:01:58 +11:00

126 lines
3.0 KiB
C

/*
* Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
* <benh@kernel.crashing.org>
* and Arnd Bergmann, 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.
*
*/
#undef DEBUG
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/mod_devicetable.h>
#include <linux/pci.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/atomic.h>
#include <asm/errno.h>
#include <asm/topology.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
#include <asm/eeh.h>
#ifdef CONFIG_PPC_OF_PLATFORM_PCI
/* The probing of PCI controllers from of_platform is currently
* 64 bits only, mostly due to gratuitous differences between
* the 32 and 64 bits PCI code on PowerPC and the 32 bits one
* lacking some bits needed here.
*/
static int of_pci_phb_probe(struct platform_device *dev)
{
struct pci_controller *phb;
/* Check if we can do that ... */
if (ppc_md.pci_setup_phb == NULL)
return -ENODEV;
pr_info("Setting up PCI bus %s\n", dev->dev.of_node->full_name);
/* Alloc and setup PHB data structure */
phb = pcibios_alloc_controller(dev->dev.of_node);
if (!phb)
return -ENODEV;
/* Setup parent in sysfs */
phb->parent = &dev->dev;
/* Setup the PHB using arch provided callback */
if (ppc_md.pci_setup_phb(phb)) {
pcibios_free_controller(phb);
return -ENODEV;
}
/* Process "ranges" property */
pci_process_bridge_OF_ranges(phb, dev->dev.of_node, 0);
/* Init pci_dn data structures */
pci_devs_phb_init_dynamic(phb);
/* Create EEH devices for the PHB */
eeh_dev_phb_init_dynamic(phb);
/* Register devices with EEH */
if (dev->dev.of_node->child)
eeh_add_device_tree_early(dev->dev.of_node);
/* Scan the bus */
pcibios_scan_phb(phb);
if (phb->bus == NULL)
return -ENXIO;
/* Claim resources. This might need some rework as well depending
* whether we are doing probe-only or not, like assigning unassigned
* resources etc...
*/
pcibios_claim_one_bus(phb->bus);
/* Finish EEH setup */
eeh_add_device_tree_late(phb->bus);
/* Add probed PCI devices to the device model */
pci_bus_add_devices(phb->bus);
/* sysfs files should only be added after devices are added */
eeh_add_sysfs_files(phb->bus);
return 0;
}
static struct of_device_id of_pci_phb_ids[] = {
{ .type = "pci", },
{ .type = "pcix", },
{ .type = "pcie", },
{ .type = "pciex", },
{ .type = "ht", },
{}
};
static struct platform_driver of_pci_phb_driver = {
.probe = of_pci_phb_probe,
.driver = {
.name = "of-pci",
.owner = THIS_MODULE,
.of_match_table = of_pci_phb_ids,
},
};
static __init int of_pci_phb_init(void)
{
return platform_driver_register(&of_pci_phb_driver);
}
device_initcall(of_pci_phb_init);
#endif /* CONFIG_PPC_OF_PLATFORM_PCI */