1What:		/sys/bus/pci/drivers/.../bind
2Date:		December 2003
3Contact:	linux-pci@vger.kernel.org
4Description:
5		Writing a device location to this file will cause
6		the driver to attempt to bind to the device found at
7		this location.	This is useful for overriding default
8		bindings.  The format for the location is: DDDD:BB:DD.F.
9		That is Domain:Bus:Device.Function and is the same as
10		found in /sys/bus/pci/devices/.  For example:
11		# echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/bind
12		(Note: kernels before 2.6.28 may require echo -n).
13
14What:		/sys/bus/pci/drivers/.../unbind
15Date:		December 2003
16Contact:	linux-pci@vger.kernel.org
17Description:
18		Writing a device location to this file will cause the
19		driver to attempt to unbind from the device found at
20		this location.	This may be useful when overriding default
21		bindings.  The format for the location is: DDDD:BB:DD.F.
22		That is Domain:Bus:Device.Function and is the same as
23		found in /sys/bus/pci/devices/. For example:
24		# echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/unbind
25		(Note: kernels before 2.6.28 may require echo -n).
26
27What:		/sys/bus/pci/drivers/.../new_id
28Date:		December 2003
29Contact:	linux-pci@vger.kernel.org
30Description:
31		Writing a device ID to this file will attempt to
32		dynamically add a new device ID to a PCI device driver.
33		This may allow the driver to support more hardware than
34		was included in the driver's static device ID support
35		table at compile time.  The format for the device ID is:
36		VVVV DDDD SVVV SDDD CCCC MMMM PPPP.  That is Vendor ID,
37		Device ID, Subsystem Vendor ID, Subsystem Device ID,
38		Class, Class Mask, and Private Driver Data.  The Vendor ID
39		and Device ID fields are required, the rest are optional.
40		Upon successfully adding an ID, the driver will probe
41		for the device and attempt to bind to it.  For example:
42		# echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_id
43
44What:		/sys/bus/pci/drivers/.../remove_id
45Date:		February 2009
46Contact:	Chris Wright <chrisw@sous-sol.org>
47Description:
48		Writing a device ID to this file will remove an ID
49		that was dynamically added via the new_id sysfs entry.
50		The format for the device ID is:
51		VVVV DDDD SVVV SDDD CCCC MMMM.	That is Vendor ID, Device
52		ID, Subsystem Vendor ID, Subsystem Device ID, Class,
53		and Class Mask.  The Vendor ID and Device ID fields are
54		required, the rest are optional.  After successfully
55		removing an ID, the driver will no longer support the
56		device.  This is useful to ensure auto probing won't
57		match the driver to the device.  For example:
58		# echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id
59
60What:		/sys/bus/pci/rescan
61Date:		January 2009
62Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
63Description:
64		Writing a non-zero value to this attribute will
65		force a rescan of all PCI buses in the system, and
66		re-discover previously removed devices.
67
68What:		/sys/bus/pci/devices/.../msi_bus
69Date:		September 2014
70Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
71Description:
72		Writing a zero value to this attribute disallows MSI and
73		MSI-X for any future drivers of the device.  If the device
74		is a bridge, MSI and MSI-X will be disallowed for future
75		drivers of all child devices under the bridge.  Drivers
76		must be reloaded for the new setting to take effect.
77
78What:		/sys/bus/pci/devices/.../msi_irqs/
79Date:		September, 2011
80Contact:	Neil Horman <nhorman@tuxdriver.com>
81Description:
82		The /sys/devices/.../msi_irqs directory contains a variable set
83		of files, with each file being named after a corresponding msi
84		irq vector allocated to that device.
85
86What:		/sys/bus/pci/devices/.../msi_irqs/<N>
87Date:		September 2011
88Contact:	Neil Horman <nhorman@tuxdriver.com>
89Description:
90		This attribute indicates the mode that the irq vector named by
91		the file is in (msi vs. msix)
92
93What:		/sys/bus/pci/devices/.../remove
94Date:		January 2009
95Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
96Description:
97		Writing a non-zero value to this attribute will
98		hot-remove the PCI device and any of its children.
99
100What:		/sys/bus/pci/devices/.../pci_bus/.../rescan
101Date:		May 2011
102Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
103Description:
104		Writing a non-zero value to this attribute will
105		force a rescan of the bus and all child buses,
106		and re-discover devices removed earlier from this
107		part of the device tree.
108
109What:		/sys/bus/pci/devices/.../rescan
110Date:		January 2009
111Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
112Description:
113		Writing a non-zero value to this attribute will
114		force a rescan of the device's parent bus and all
115		child buses, and re-discover devices removed earlier
116		from this part of the device tree.
117
118What:		/sys/bus/pci/devices/.../reset
119Date:		July 2009
120Contact:	Michael S. Tsirkin <mst@redhat.com>
121Description:
122		Some devices allow an individual function to be reset
123		without affecting other functions in the same device.
124		For devices that have this support, a file named reset
125		will be present in sysfs.  Writing 1 to this file
126		will perform reset.
127
128What:		/sys/bus/pci/devices/.../vpd
129Date:		February 2008
130Contact:	Ben Hutchings <bwh@kernel.org>
131Description:
132		A file named vpd in a device directory will be a
133		binary file containing the Vital Product Data for the
134		device.  It should follow the VPD format defined in
135		PCI Specification 2.1 or 2.2, but users should consider
136		that some devices may have malformatted data.  If the
137		underlying VPD has a writable section then the
138		corresponding section of this file will be writable.
139
140What:		/sys/bus/pci/devices/.../virtfnN
141Date:		March 2009
142Contact:	Yu Zhao <yu.zhao@intel.com>
143Description:
144		This symbolic link appears when hardware supports the SR-IOV
145		capability and the Physical Function driver has enabled it.
146		The symbolic link points to the PCI device sysfs entry of the
147		Virtual Function whose index is N (0...MaxVFs-1).
148
149What:		/sys/bus/pci/devices/.../dep_link
150Date:		March 2009
151Contact:	Yu Zhao <yu.zhao@intel.com>
152Description:
153		This symbolic link appears when hardware supports the SR-IOV
154		capability and the Physical Function driver has enabled it,
155		and this device has vendor specific dependencies with others.
156		The symbolic link points to the PCI device sysfs entry of
157		Physical Function this device depends on.
158
159What:		/sys/bus/pci/devices/.../physfn
160Date:		March 2009
161Contact:	Yu Zhao <yu.zhao@intel.com>
162Description:
163		This symbolic link appears when a device is a Virtual Function.
164		The symbolic link points to the PCI device sysfs entry of the
165		Physical Function this device associates with.
166
167What:		/sys/bus/pci/slots/.../module
168Date:		June 2009
169Contact:	linux-pci@vger.kernel.org
170Description:
171		This symbolic link points to the PCI hotplug controller driver
172		module that manages the hotplug slot.
173
174What:		/sys/bus/pci/devices/.../label
175Date:		July 2010
176Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
177Description:
178		Reading this attribute will provide the firmware
179		given name (SMBIOS type 41 string or ACPI _DSM string) of
180		the PCI device.	The attribute will be created only
181		if the firmware	has given a name to the PCI device.
182		ACPI _DSM string name will be given priority if the
183		system firmware provides SMBIOS type 41 string also.
184Users:
185		Userspace applications interested in knowing the
186		firmware assigned name of the PCI device.
187
188What:		/sys/bus/pci/devices/.../index
189Date:		July 2010
190Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
191Description:
192		Reading this attribute will provide the firmware
193		given instance (SMBIOS type 41 device type instance) of the
194		PCI device. The attribute will be created only if the firmware
195		has given an instance number to the PCI device.
196Users:
197		Userspace applications interested in knowing the
198		firmware assigned device type instance of the PCI
199		device that can help in understanding the firmware
200		intended order of the PCI device.
201
202What:		/sys/bus/pci/devices/.../acpi_index
203Date:		July 2010
204Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
205Description:
206		Reading this attribute will provide the firmware
207		given instance (ACPI _DSM instance number) of the PCI device.
208		The attribute will be created only if the firmware has given
209		an instance number to the PCI device. ACPI _DSM instance number
210		will be given priority if the system firmware provides SMBIOS
211		type 41 device type instance also.
212Users:
213		Userspace applications interested in knowing the
214		firmware assigned instance number of the PCI
215		device that can help in understanding the firmware
216		intended order of the PCI device.
217
218What:		/sys/bus/pci/devices/.../d3cold_allowed
219Date:		July 2012
220Contact:	Huang Ying <ying.huang@intel.com>
221Description:
222		d3cold_allowed is bit to control whether the corresponding PCI
223		device can be put into D3Cold state.  If it is cleared, the
224		device will never be put into D3Cold state.  If it is set, the
225		device may be put into D3Cold state if other requirements are
226		satisfied too.  Reading this attribute will show the current
227		value of d3cold_allowed bit.  Writing this attribute will set
228		the value of d3cold_allowed bit.
229
230What:		/sys/bus/pci/devices/.../sriov_totalvfs
231Date:		November 2012
232Contact:	Donald Dutile <ddutile@redhat.com>
233Description:
234		This file appears when a physical PCIe device supports SR-IOV.
235		Userspace applications can read this file to determine the
236		maximum number of Virtual Functions (VFs) a PCIe physical
237		function (PF) can support. Typically, this is the value reported
238		in the PF's SR-IOV extended capability structure's TotalVFs
239		element.  Drivers have the ability at probe time to reduce the
240		value read from this file via the pci_sriov_set_totalvfs()
241		function.
242
243What:		/sys/bus/pci/devices/.../sriov_numvfs
244Date:		November 2012
245Contact:	Donald Dutile <ddutile@redhat.com>
246Description:
247		This file appears when a physical PCIe device supports SR-IOV.
248		Userspace applications can read and write to this file to
249		determine and control the enablement or disablement of Virtual
250		Functions (VFs) on the physical function (PF). A read of this
251		file will return the number of VFs that are enabled on this PF.
252		A number written to this file will enable the specified
253		number of VFs. A userspace application would typically read the
254		file and check that the value is zero, and then write the number
255		of VFs that should be enabled on the PF; the value written
256		should be less than or equal to the value in the sriov_totalvfs
257		file. A userspace application wanting to disable the VFs would
258		write a zero to this file. The core ensures that valid values
259		are written to this file, and returns errors when values are not
260		valid.  For example, writing a 2 to this file when sriov_numvfs
261		is not 0 and not 2 already will return an error. Writing a 10
262		when the value of sriov_totalvfs is 8 will return an error.
263
264What:		/sys/bus/pci/devices/.../driver_override
265Date:		April 2014
266Contact:	Alex Williamson <alex.williamson@redhat.com>
267Description:
268		This file allows the driver for a device to be specified which
269		will override standard static and dynamic ID matching.  When
270		specified, only a driver with a name matching the value written
271		to driver_override will have an opportunity to bind to the
272		device.  The override is specified by writing a string to the
273		driver_override file (echo pci-stub > driver_override) and
274		may be cleared with an empty string (echo > driver_override).
275		This returns the device to standard matching rules binding.
276		Writing to driver_override does not automatically unbind the
277		device from its current driver or make any attempt to
278		automatically load the specified driver.  If no driver with a
279		matching name is currently loaded in the kernel, the device
280		will not bind to any driver.  This also allows devices to
281		opt-out of driver binding using a driver_override name such as
282		"none".  Only a single driver may be specified in the override,
283		there is no support for parsing delimiters.
284
285What:		/sys/bus/pci/devices/.../numa_node
286Date:		Oct 2014
287Contact:	Prarit Bhargava <prarit@redhat.com>
288Description:
289		This file contains the NUMA node to which the PCI device is
290		attached, or -1 if the node is unknown.  The initial value
291		comes from an ACPI _PXM method or a similar firmware
292		source.  If that is missing or incorrect, this file can be
293		written to override the node.  In that case, please report
294		a firmware bug to the system vendor.  Writing to this file
295		taints the kernel with TAINT_FIRMWARE_WORKAROUND, which
296		reduces the supportability of your system.
297