linux/drivers/pci/host/pci-host-generic.c
Brian Norris a5f40e8098 PCI: Don't allow unbinding host controllers that aren't prepared
Many PCI host controller drivers aren't prepared to have their devices
unbound from them forcefully (e.g., through /sys/.../<driver>/unbind), as
they don't provide any driver .remove callback, where they'd detach the
root bus, release resources, etc. Keeping the driver built in (i.e., not a
loadable module) is not enough; and providing no .remove callback just
means we don't do any teardown.

To rule out the possibility of unbinding a device via sysfs, we need to set
the ".suppress_bind_attrs" field.

I found the suspect drivers via the following search:

  git grep -l platform_driver $(git grep -L -e '\.remove' -e suppress_bind_attrs drivers/pci/)

Then I inspected them to ensure that
(a) they set up a PCI bus in their probe() and
(b) they don't have a remove() callback for undoing the setup

Suggested-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-04-28 10:38:00 -05:00

68 lines
1.9 KiB
C

/*
* Simple, generic PCI host controller driver targetting firmware-initialised
* systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright (C) 2014 ARM Limited
*
* Author: Will Deacon <will.deacon@arm.com>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/pci-ecam.h>
#include <linux/platform_device.h>
static struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
.bus_shift = 16,
.pci_ops = {
.map_bus = pci_ecam_map_bus,
.read = pci_generic_config_read,
.write = pci_generic_config_write,
}
};
static const struct of_device_id gen_pci_of_match[] = {
{ .compatible = "pci-host-cam-generic",
.data = &gen_pci_cfg_cam_bus_ops },
{ .compatible = "pci-host-ecam-generic",
.data = &pci_generic_ecam_ops },
{ },
};
static int gen_pci_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id;
struct pci_ecam_ops *ops;
of_id = of_match_node(gen_pci_of_match, pdev->dev.of_node);
ops = (struct pci_ecam_ops *)of_id->data;
return pci_host_common_probe(pdev, ops);
}
static struct platform_driver gen_pci_driver = {
.driver = {
.name = "pci-host-generic",
.of_match_table = gen_pci_of_match,
.suppress_bind_attrs = true,
},
.probe = gen_pci_probe,
};
builtin_platform_driver(gen_pci_driver);