PCI: Introduce /sys/bus/pci/rescan

This interface allows the user to force a rescan of all PCI buses
in system, and rediscover devices that have been removed earlier.

pci_bus_attrs implementation from Trent Piepho.

Thanks to Vegard Nossum for discovering locking issues with the
sysfs interface.

Cc: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index d175a2a5fac2..e6ad047cb3c2 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -57,6 +57,15 @@ Description:
                 match the driver to the device.  For example:
                 # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id
 
+What:           /sys/bus/pci/rescan
+Date:           January 2009
+Contact:        Linux PCI developers <linux-pci@vger.kernel.org>
+Description:
+                Writing a non-zero value to this attribute will
+                force a rescan of all PCI buses in the system, and
+                re-discover previously removed devices.
+                Depends on CONFIG_HOTPLUG.
+
 What:           /sys/bus/pci/devices/.../vpd
 Date:           February 2008
 Contact:        Ben Hutchings <bhutchings@solarflare.com>