linux/drivers/pci/remove.c
Lukas Wunner 035ee288ae PCI: Fix bridge_d3 update on device removal
Starting with v4.8, we allow a PCIe port to runtime suspend to D3hot if the
port itself and its children satisfy a number of conditions.  Once a child
is removed, we recheck those conditions in case the removed device was
blocking the port from suspending.

The rechecking needs to happen *after* the device has been removed from the
bus it resides on.  Otherwise when walking the port's subordinate bus in
pci_bridge_d3_update(), the device being removed would erroneously still be
taken into account.

However the device is removed from the bus_list in pci_destroy_dev() and we
currently recheck *before* that.  Fix it.

Fixes: 9d26d3a8f1 ("PCI: Put PCIe ports into D3 during suspend")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <mika.westerberg@linux.intel.com>
2016-09-13 16:00:18 -05:00

167 lines
3.7 KiB
C

#include <linux/pci.h>
#include <linux/module.h>
#include <linux/pci-aspm.h>
#include "pci.h"
static void pci_free_resources(struct pci_dev *dev)
{
int i;
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
struct resource *res = dev->resource + i;
if (res->parent)
release_resource(res);
}
}
static void pci_stop_dev(struct pci_dev *dev)
{
pci_pme_active(dev, false);
if (dev->is_added) {
pci_proc_detach_device(dev);
pci_remove_sysfs_dev_files(dev);
device_release_driver(&dev->dev);
dev->is_added = 0;
}
if (dev->bus->self)
pcie_aspm_exit_link_state(dev);
}
static void pci_destroy_dev(struct pci_dev *dev)
{
if (!dev->dev.kobj.parent)
return;
device_del(&dev->dev);
down_write(&pci_bus_sem);
list_del(&dev->bus_list);
up_write(&pci_bus_sem);
pci_bridge_d3_device_removed(dev);
pci_free_resources(dev);
put_device(&dev->dev);
}
void pci_remove_bus(struct pci_bus *bus)
{
pci_proc_detach_bus(bus);
down_write(&pci_bus_sem);
list_del(&bus->node);
pci_bus_release_busn_res(bus);
up_write(&pci_bus_sem);
pci_remove_legacy_files(bus);
if (bus->ops->remove_bus)
bus->ops->remove_bus(bus);
pcibios_remove_bus(bus);
device_unregister(&bus->dev);
}
EXPORT_SYMBOL(pci_remove_bus);
static void pci_stop_bus_device(struct pci_dev *dev)
{
struct pci_bus *bus = dev->subordinate;
struct pci_dev *child, *tmp;
/*
* Stopping an SR-IOV PF device removes all the associated VFs,
* which will update the bus->devices list and confuse the
* iterator. Therefore, iterate in reverse so we remove the VFs
* first, then the PF.
*/
if (bus) {
list_for_each_entry_safe_reverse(child, tmp,
&bus->devices, bus_list)
pci_stop_bus_device(child);
}
pci_stop_dev(dev);
}
static void pci_remove_bus_device(struct pci_dev *dev)
{
struct pci_bus *bus = dev->subordinate;
struct pci_dev *child, *tmp;
if (bus) {
list_for_each_entry_safe(child, tmp,
&bus->devices, bus_list)
pci_remove_bus_device(child);
pci_remove_bus(bus);
dev->subordinate = NULL;
}
pci_destroy_dev(dev);
}
/**
* pci_stop_and_remove_bus_device - remove a PCI device and any children
* @dev: the device to remove
*
* Remove a PCI device from the device lists, informing the drivers
* that the device has been removed. We also remove any subordinate
* buses and children in a depth-first manner.
*
* For each device we remove, delete the device structure from the
* device lists, remove the /proc entry, and notify userspace
* (/sbin/hotplug).
*/
void pci_stop_and_remove_bus_device(struct pci_dev *dev)
{
pci_stop_bus_device(dev);
pci_remove_bus_device(dev);
}
EXPORT_SYMBOL(pci_stop_and_remove_bus_device);
void pci_stop_and_remove_bus_device_locked(struct pci_dev *dev)
{
pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(dev);
pci_unlock_rescan_remove();
}
EXPORT_SYMBOL_GPL(pci_stop_and_remove_bus_device_locked);
void pci_stop_root_bus(struct pci_bus *bus)
{
struct pci_dev *child, *tmp;
struct pci_host_bridge *host_bridge;
if (!pci_is_root_bus(bus))
return;
host_bridge = to_pci_host_bridge(bus->bridge);
list_for_each_entry_safe_reverse(child, tmp,
&bus->devices, bus_list)
pci_stop_bus_device(child);
/* stop the host bridge */
device_release_driver(&host_bridge->dev);
}
EXPORT_SYMBOL_GPL(pci_stop_root_bus);
void pci_remove_root_bus(struct pci_bus *bus)
{
struct pci_dev *child, *tmp;
struct pci_host_bridge *host_bridge;
if (!pci_is_root_bus(bus))
return;
host_bridge = to_pci_host_bridge(bus->bridge);
list_for_each_entry_safe(child, tmp,
&bus->devices, bus_list)
pci_remove_bus_device(child);
pci_remove_bus(bus);
host_bridge->bus = NULL;
/* remove the host bridge */
device_unregister(&host_bridge->dev);
}
EXPORT_SYMBOL_GPL(pci_remove_root_bus);