PCI: expose function reset capability in sysfs

Some devices allow an individual function to be reset without affecting
other functions in the same device: that's what pci_reset_function does.
For devices that have this support, expose reset attribite in sysfs.

This is useful e.g. for virtualization, where a qemu userspace
process wants to reset the device when the guest is reset,
to emulate machine reboot as closely as possible.

Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 6bf68053e4b8..25be3250f7d6 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -84,6 +84,16 @@ Description:
                 from this part of the device tree.
                 Depends on CONFIG_HOTPLUG.
 
+What:           /sys/bus/pci/devices/.../reset
+Date:           July 2009
+Contact:        Michael S. Tsirkin <mst@redhat.com>
+Description:
+                Some devices allow an individual function to be reset
+                without affecting other functions in the same device.
+                For devices that have this support, a file named reset
+                will be present in sysfs.  Writing 1 to this file
+                will perform reset.
+
 What:           /sys/bus/pci/devices/.../vpd
 Date:           February 2008
 Contact:        Ben Hutchings <bhutchings@solarflare.com>