linux/drivers/pci/remove.c
Lukas Wunner 1ed276a7b9 PCI: Autosense device removal in pci_bridge_d3_update()
The algorithm to update the flag indicating whether a bridge may go to D3
makes a few optimizations based on whether the update was caused by the
removal of a device on the one hand, versus the addition of a device or the
change of its D3cold flags on the other hand.

The information whether the update pertains to a removal is currently
passed in by the caller, but the function may as well determine that itself
by examining the device in question, thereby allowing for a considerable
simplification and reduction of the code.

Out of several options to determine removal, I've chosen the function
device_is_registered() because it's cheap:  It merely returns the
dev->kobj.state_in_sysfs flag.  That flag is set through device_add() when
the root bus is scanned and cleared through device_remove().  The call to
pci_bridge_d3_update() happens after each of these calls, respectively, so
the ordering is correct.

No functional change intended.

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-17 18:44:56 -06:00

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_update(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);