1What:		/sys/bus/pci/drivers/.../bind
2What:		/sys/devices/pciX/.../bind
3Date:		December 2003
4Contact:	linux-pci@vger.kernel.org
5Description:
6		Writing a device location to this file will cause
7		the driver to attempt to bind to the device found at
8		this location.	This is useful for overriding default
9		bindings.  The format for the location is: DDDD:BB:DD.F.
10		That is Domain:Bus:Device.Function and is the same as
11		found in /sys/bus/pci/devices/.  For example::
12
13		  # echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/bind
14
15		(Note: kernels before 2.6.28 may require echo -n).
16
17What:		/sys/bus/pci/drivers/.../unbind
18What:		/sys/devices/pciX/.../unbind
19Date:		December 2003
20Contact:	linux-pci@vger.kernel.org
21Description:
22		Writing a device location to this file will cause the
23		driver to attempt to unbind from the device found at
24		this location.	This may be useful when overriding default
25		bindings.  The format for the location is: DDDD:BB:DD.F.
26		That is Domain:Bus:Device.Function and is the same as
27		found in /sys/bus/pci/devices/. For example::
28
29		  # echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/unbind
30
31		(Note: kernels before 2.6.28 may require echo -n).
32
33What:		/sys/bus/pci/drivers/.../new_id
34What:		/sys/devices/pciX/.../new_id
35Date:		December 2003
36Contact:	linux-pci@vger.kernel.org
37Description:
38		Writing a device ID to this file will attempt to
39		dynamically add a new device ID to a PCI device driver.
40		This may allow the driver to support more hardware than
41		was included in the driver's static device ID support
42		table at compile time.  The format for the device ID is:
43		VVVV DDDD SVVV SDDD CCCC MMMM PPPP.  That is Vendor ID,
44		Device ID, Subsystem Vendor ID, Subsystem Device ID,
45		Class, Class Mask, and Private Driver Data.  The Vendor ID
46		and Device ID fields are required, the rest are optional.
47		Upon successfully adding an ID, the driver will probe
48		for the device and attempt to bind to it.  For example::
49
50		  # echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_id
51
52What:		/sys/bus/pci/drivers/.../remove_id
53What:		/sys/devices/pciX/.../remove_id
54Date:		February 2009
55Contact:	Chris Wright <chrisw@sous-sol.org>
56Description:
57		Writing a device ID to this file will remove an ID
58		that was dynamically added via the new_id sysfs entry.
59		The format for the device ID is:
60		VVVV DDDD SVVV SDDD CCCC MMMM.	That is Vendor ID, Device
61		ID, Subsystem Vendor ID, Subsystem Device ID, Class,
62		and Class Mask.  The Vendor ID and Device ID fields are
63		required, the rest are optional.  After successfully
64		removing an ID, the driver will no longer support the
65		device.  This is useful to ensure auto probing won't
66		match the driver to the device.  For example::
67
68		  # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id
69
70What:		/sys/bus/pci/rescan
71Date:		January 2009
72Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
73Description:
74		Writing a non-zero value to this attribute will
75		force a rescan of all PCI buses in the system, and
76		re-discover previously removed devices.
77
78What:		/sys/bus/pci/devices/.../msi_bus
79Date:		September 2014
80Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
81Description:
82		Writing a zero value to this attribute disallows MSI and
83		MSI-X for any future drivers of the device.  If the device
84		is a bridge, MSI and MSI-X will be disallowed for future
85		drivers of all child devices under the bridge.  Drivers
86		must be reloaded for the new setting to take effect.
87
88What:		/sys/bus/pci/devices/.../msi_irqs/
89Date:		September, 2011
90Contact:	Neil Horman <nhorman@tuxdriver.com>
91Description:
92		The /sys/devices/.../msi_irqs directory contains a variable set
93		of files, with each file being named after a corresponding msi
94		irq vector allocated to that device.
95
96What:		/sys/bus/pci/devices/.../msi_irqs/<N>
97Date:		September 2011
98Contact:	Neil Horman <nhorman@tuxdriver.com>
99Description:
100		This attribute indicates the mode that the irq vector named by
101		the file is in (msi vs. msix)
102
103What:		/sys/bus/pci/devices/.../irq
104Date:		August 2021
105Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
106Description:
107		If a driver has enabled MSI (not MSI-X), "irq" contains the
108		IRQ of the first MSI vector. Otherwise "irq" contains the
109		IRQ of the legacy INTx interrupt.
110
111		"irq" being set to 0 indicates that the device isn't
112		capable of generating legacy INTx interrupts.
113
114What:		/sys/bus/pci/devices/.../remove
115Date:		January 2009
116Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
117Description:
118		Writing a non-zero value to this attribute will
119		hot-remove the PCI device and any of its children.
120
121What:		/sys/bus/pci/devices/.../pci_bus/.../rescan
122Date:		May 2011
123Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
124Description:
125		Writing a non-zero value to this attribute will
126		force a rescan of the bus and all child buses,
127		and re-discover devices removed earlier from this
128		part of the device tree.
129
130What:		/sys/bus/pci/devices/.../rescan
131Date:		January 2009
132Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
133Description:
134		Writing a non-zero value to this attribute will
135		force a rescan of the device's parent bus and all
136		child buses, and re-discover devices removed earlier
137		from this part of the device tree.
138
139What:		/sys/bus/pci/devices/.../reset_method
140Date:		August 2021
141Contact:	Amey Narkhede <ameynarkhede03@gmail.com>
142Description:
143		Some devices allow an individual function to be reset
144		without affecting other functions in the same slot.
145
146		For devices that have this support, a file named
147		reset_method is present in sysfs.  Reading this file
148		gives names of the supported and enabled reset methods and
149		their ordering.  Writing a space-separated list of names of
150		reset methods sets the reset methods and ordering to be
151		used when resetting the device.  Writing an empty string
152		disables the ability to reset the device.  Writing
153		"default" enables all supported reset methods in the
154		default ordering.
155
156What:		/sys/bus/pci/devices/.../reset
157Date:		July 2009
158Contact:	Michael S. Tsirkin <mst@redhat.com>
159Description:
160		Some devices allow an individual function to be reset
161		without affecting other functions in the same device.
162		For devices that have this support, a file named reset
163		will be present in sysfs.  Writing 1 to this file
164		will perform reset.
165
166What:		/sys/bus/pci/devices/.../vpd
167Date:		February 2008
168Contact:	Ben Hutchings <bwh@kernel.org>
169Description:
170		A file named vpd in a device directory will be a
171		binary file containing the Vital Product Data for the
172		device.  It should follow the VPD format defined in
173		PCI Specification 2.1 or 2.2, but users should consider
174		that some devices may have incorrectly formatted data.
175		If the underlying VPD has a writable section then the
176		corresponding section of this file will be writable.
177
178What:		/sys/bus/pci/devices/.../virtfn<N>
179Date:		March 2009
180Contact:	Yu Zhao <yu.zhao@intel.com>
181Description:
182		This symbolic link appears when hardware supports the SR-IOV
183		capability and the Physical Function driver has enabled it.
184		The symbolic link points to the PCI device sysfs entry of the
185		Virtual Function whose index is N (0...MaxVFs-1).
186
187What:		/sys/bus/pci/devices/.../dep_link
188Date:		March 2009
189Contact:	Yu Zhao <yu.zhao@intel.com>
190Description:
191		This symbolic link appears when hardware supports the SR-IOV
192		capability and the Physical Function driver has enabled it,
193		and this device has vendor specific dependencies with others.
194		The symbolic link points to the PCI device sysfs entry of
195		Physical Function this device depends on.
196
197What:		/sys/bus/pci/devices/.../physfn
198Date:		March 2009
199Contact:	Yu Zhao <yu.zhao@intel.com>
200Description:
201		This symbolic link appears when a device is a Virtual Function.
202		The symbolic link points to the PCI device sysfs entry of the
203		Physical Function this device associates with.
204
205What:		/sys/bus/pci/devices/.../modalias
206Date:		May 2005
207Contact:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
208Description:
209		This attribute indicates the PCI ID of the device object.
210
211		That is in the format:
212		pci:vXXXXXXXXdXXXXXXXXsvXXXXXXXXsdXXXXXXXXbcXXscXXiXX,
213		where:
214
215		    - vXXXXXXXX contains the vendor ID;
216		    - dXXXXXXXX contains the device ID;
217		    - svXXXXXXXX contains the sub-vendor ID;
218		    - sdXXXXXXXX contains the subsystem device ID;
219		    - bcXX contains the device class;
220		    - scXX contains the device subclass;
221		    - iXX contains the device class programming interface.
222
223What:		/sys/bus/pci/slots/.../module
224Date:		June 2009
225Contact:	linux-pci@vger.kernel.org
226Description:
227		This symbolic link points to the PCI hotplug controller driver
228		module that manages the hotplug slot.
229
230What:		/sys/bus/pci/devices/.../label
231Date:		July 2010
232Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
233Description:
234		Reading this attribute will provide the firmware
235		given name (SMBIOS type 41 string or ACPI _DSM string) of
236		the PCI device.	The attribute will be created only
237		if the firmware	has given a name to the PCI device.
238		ACPI _DSM string name will be given priority if the
239		system firmware provides SMBIOS type 41 string also.
240Users:
241		Userspace applications interested in knowing the
242		firmware assigned name of the PCI device.
243
244What:		/sys/bus/pci/devices/.../index
245Date:		July 2010
246Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
247Description:
248		Reading this attribute will provide the firmware given instance
249		number of the PCI device.  Depending on the platform this can
250		be for example the SMBIOS type 41 device type instance or the
251		user-defined ID (UID) on s390. The attribute will be created
252		only if the firmware has given an instance number to the PCI
253		device and that number is guaranteed to uniquely identify the
254		device in the system.
255Users:
256		Userspace applications interested in knowing the
257		firmware assigned device type instance of the PCI
258		device that can help in understanding the firmware
259		intended order of the PCI device.
260
261What:		/sys/bus/pci/devices/.../acpi_index
262Date:		July 2010
263Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
264Description:
265		Reading this attribute will provide the firmware
266		given instance (ACPI _DSM instance number) of the PCI device.
267		The attribute will be created only if the firmware has given
268		an instance number to the PCI device. ACPI _DSM instance number
269		will be given priority if the system firmware provides SMBIOS
270		type 41 device type instance also.
271Users:
272		Userspace applications interested in knowing the
273		firmware assigned instance number of the PCI
274		device that can help in understanding the firmware
275		intended order of the PCI device.
276
277What:		/sys/bus/pci/devices/.../d3cold_allowed
278Date:		July 2012
279Contact:	Huang Ying <ying.huang@intel.com>
280Description:
281		d3cold_allowed is bit to control whether the corresponding PCI
282		device can be put into D3Cold state.  If it is cleared, the
283		device will never be put into D3Cold state.  If it is set, the
284		device may be put into D3Cold state if other requirements are
285		satisfied too.  Reading this attribute will show the current
286		value of d3cold_allowed bit.  Writing this attribute will set
287		the value of d3cold_allowed bit.
288
289What:		/sys/bus/pci/devices/.../sriov_totalvfs
290Date:		November 2012
291Contact:	Donald Dutile <ddutile@redhat.com>
292Description:
293		This file appears when a physical PCIe device supports SR-IOV.
294		Userspace applications can read this file to determine the
295		maximum number of Virtual Functions (VFs) a PCIe physical
296		function (PF) can support. Typically, this is the value reported
297		in the PF's SR-IOV extended capability structure's TotalVFs
298		element.  Drivers have the ability at probe time to reduce the
299		value read from this file via the pci_sriov_set_totalvfs()
300		function.
301
302What:		/sys/bus/pci/devices/.../sriov_numvfs
303Date:		November 2012
304Contact:	Donald Dutile <ddutile@redhat.com>
305Description:
306		This file appears when a physical PCIe device supports SR-IOV.
307		Userspace applications can read and write to this file to
308		determine and control the enablement or disablement of Virtual
309		Functions (VFs) on the physical function (PF). A read of this
310		file will return the number of VFs that are enabled on this PF.
311		A number written to this file will enable the specified
312		number of VFs. A userspace application would typically read the
313		file and check that the value is zero, and then write the number
314		of VFs that should be enabled on the PF; the value written
315		should be less than or equal to the value in the sriov_totalvfs
316		file. A userspace application wanting to disable the VFs would
317		write a zero to this file. The core ensures that valid values
318		are written to this file, and returns errors when values are not
319		valid.  For example, writing a 2 to this file when sriov_numvfs
320		is not 0 and not 2 already will return an error. Writing a 10
321		when the value of sriov_totalvfs is 8 will return an error.
322
323What:		/sys/bus/pci/devices/.../driver_override
324Date:		April 2014
325Contact:	Alex Williamson <alex.williamson@redhat.com>
326Description:
327		This file allows the driver for a device to be specified which
328		will override standard static and dynamic ID matching.  When
329		specified, only a driver with a name matching the value written
330		to driver_override will have an opportunity to bind to the
331		device.  The override is specified by writing a string to the
332		driver_override file (echo pci-stub > driver_override) and
333		may be cleared with an empty string (echo > driver_override).
334		This returns the device to standard matching rules binding.
335		Writing to driver_override does not automatically unbind the
336		device from its current driver or make any attempt to
337		automatically load the specified driver.  If no driver with a
338		matching name is currently loaded in the kernel, the device
339		will not bind to any driver.  This also allows devices to
340		opt-out of driver binding using a driver_override name such as
341		"none".  Only a single driver may be specified in the override,
342		there is no support for parsing delimiters.
343
344What:		/sys/bus/pci/devices/.../numa_node
345Date:		Oct 2014
346Contact:	Prarit Bhargava <prarit@redhat.com>
347Description:
348		This file contains the NUMA node to which the PCI device is
349		attached, or -1 if the node is unknown.  The initial value
350		comes from an ACPI _PXM method or a similar firmware
351		source.  If that is missing or incorrect, this file can be
352		written to override the node.  In that case, please report
353		a firmware bug to the system vendor.  Writing to this file
354		taints the kernel with TAINT_FIRMWARE_WORKAROUND, which
355		reduces the supportability of your system.
356
357What:		/sys/bus/pci/devices/.../revision
358Date:		November 2016
359Contact:	Emil Velikov <emil.l.velikov@gmail.com>
360Description:
361		This file contains the revision field of the PCI device.
362		The value comes from device config space. The file is read only.
363
364What:		/sys/bus/pci/devices/.../sriov_drivers_autoprobe
365Date:		April 2017
366Contact:	Bodong Wang<bodong@mellanox.com>
367Description:
368		This file is associated with the PF of a device that
369		supports SR-IOV.  It determines whether newly-enabled VFs
370		are immediately bound to a driver.  It initially contains
371		1, which means the kernel automatically binds VFs to a
372		compatible driver immediately after they are enabled.  If
373		an application writes 0 to the file before enabling VFs,
374		the kernel will not bind VFs to a driver.
375
376		A typical use case is to write 0 to this file, then enable
377		VFs, then assign the newly-created VFs to virtual machines.
378		Note that changing this file does not affect already-
379		enabled VFs.  In this scenario, the user must first disable
380		the VFs, write 0 to sriov_drivers_autoprobe, then re-enable
381		the VFs.
382
383		This is similar to /sys/bus/pci/drivers_autoprobe, but
384		affects only the VFs associated with a specific PF.
385
386What:		/sys/bus/pci/devices/.../p2pmem/size
387Date:		November 2017
388Contact:	Logan Gunthorpe <logang@deltatee.com>
389Description:
390		If the device has any Peer-to-Peer memory registered, this
391	        file contains the total amount of memory that the device
392		provides (in decimal).
393
394What:		/sys/bus/pci/devices/.../p2pmem/available
395Date:		November 2017
396Contact:	Logan Gunthorpe <logang@deltatee.com>
397Description:
398		If the device has any Peer-to-Peer memory registered, this
399	        file contains the amount of memory that has not been
400		allocated (in decimal).
401
402What:		/sys/bus/pci/devices/.../p2pmem/published
403Date:		November 2017
404Contact:	Logan Gunthorpe <logang@deltatee.com>
405Description:
406		If the device has any Peer-to-Peer memory registered, this
407	        file contains a '1' if the memory has been published for
408		use outside the driver that owns the device.
409
410What:		/sys/bus/pci/devices/.../link/clkpm
411		/sys/bus/pci/devices/.../link/l0s_aspm
412		/sys/bus/pci/devices/.../link/l1_aspm
413		/sys/bus/pci/devices/.../link/l1_1_aspm
414		/sys/bus/pci/devices/.../link/l1_2_aspm
415		/sys/bus/pci/devices/.../link/l1_1_pcipm
416		/sys/bus/pci/devices/.../link/l1_2_pcipm
417Date:		October 2019
418Contact:	Heiner Kallweit <hkallweit1@gmail.com>
419Description:	If ASPM is supported for an endpoint, these files can be
420		used to disable or enable the individual power management
421		states. Write y/1/on to enable, n/0/off to disable.
422
423What:		/sys/bus/pci/devices/.../power_state
424Date:		November 2020
425Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
426Description:
427		This file contains the current PCI power state of the device.
428		The value comes from the PCI kernel device state and can be one
429		of: "unknown", "error", "D0", D1", "D2", "D3hot", "D3cold".
430		The file is read only.
431
432What:		/sys/bus/pci/devices/.../sriov_vf_total_msix
433Date:		January 2021
434Contact:	Leon Romanovsky <leonro@nvidia.com>
435Description:
436		This file is associated with a SR-IOV physical function (PF).
437		It contains the total number of MSI-X vectors available for
438		assignment to all virtual functions (VFs) associated with PF.
439		The value will be zero if the device doesn't support this
440		functionality. For supported devices, the value will be
441		constant and won't be changed after MSI-X vectors assignment.
442
443What:		/sys/bus/pci/devices/.../sriov_vf_msix_count
444Date:		January 2021
445Contact:	Leon Romanovsky <leonro@nvidia.com>
446Description:
447		This file is associated with a SR-IOV virtual function (VF).
448		It allows configuration of the number of MSI-X vectors for
449		the VF. This allows devices that have a global pool of MSI-X
450		vectors to optimally divide them between VFs based on VF usage.
451
452		The values accepted are:
453		 * > 0 - this number will be reported as the Table Size in the
454			 VF's MSI-X capability
455		 * < 0 - not valid
456		 * = 0 - will reset to the device default value
457
458		The file is writable if the PF is bound to a driver that
459		implements ->sriov_set_msix_vec_count().
460
461What:		/sys/bus/pci/devices/.../resourceN_resize
462Date:		September 2022
463Contact:	Alex Williamson <alex.williamson@redhat.com>
464Description:
465		These files provide an interface to PCIe Resizable BAR support.
466		A file is created for each BAR resource (N) supported by the
467		PCIe Resizable BAR extended capability of the device.  Reading
468		each file exposes the bitmap of available resource sizes:
469
470		# cat resource1_resize
471		00000000000001c0
472
473		The bitmap represents supported resource sizes for the BAR,
474		where bit0 = 1MB, bit1 = 2MB, bit2 = 4MB, etc.  In the above
475		example the device supports 64MB, 128MB, and 256MB BAR sizes.
476
477		When writing the file, the user provides the bit position of
478		the desired resource size, for example:
479
480		# echo 7 > resource1_resize
481
482		This indicates to set the size value corresponding to bit 7,
483		128MB.  The resulting size is 2 ^ (bit# + 20).  This definition
484		matches the PCIe specification of this capability.
485
486		In order to make use of resource resizing, all PCI drivers must
487		be unbound from the device and peer devices under the same
488		parent bridge may need to be soft removed.  In the case of
489		VGA devices, writing a resize value will remove low level
490		console drivers from the device.  Raw users of pci-sysfs
491		resourceN attributes must be terminated prior to resizing.
492		Success of the resizing operation is not guaranteed.
493