xref: /linux/Documentation/ABI/testing/sysfs-bus-pci (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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		Depends on CONFIG_HOTPLUG.
68
69What:		/sys/bus/pci/devices/.../msi_irqs/
70Date:		September, 2011
71Contact:	Neil Horman <nhorman@tuxdriver.com>
72Description:
73		The /sys/devices/.../msi_irqs directory contains a variable set
74		of sub-directories, with each sub-directory being named after a
75		corresponding msi irq vector allocated to that device.  Each
76		numbered sub-directory N contains attributes of that irq.
77		Note that this directory is not created for device drivers which
78		do not support msi irqs
79
80What:		/sys/bus/pci/devices/.../msi_irqs/<N>/mode
81Date:		September 2011
82Contact:	Neil Horman <nhorman@tuxdriver.com>
83Description:
84		This attribute indicates the mode that the irq vector named by
85		the parent directory is in (msi vs. msix)
86
87What:		/sys/bus/pci/devices/.../remove
88Date:		January 2009
89Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
90Description:
91		Writing a non-zero value to this attribute will
92		hot-remove the PCI device and any of its children.
93		Depends on CONFIG_HOTPLUG.
94
95What:		/sys/bus/pci/devices/.../pci_bus/.../rescan
96Date:		May 2011
97Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
98Description:
99		Writing a non-zero value to this attribute will
100		force a rescan of the bus and all child buses,
101		and re-discover devices removed earlier from this
102		part of the device tree.  Depends on CONFIG_HOTPLUG.
103
104What:		/sys/bus/pci/devices/.../rescan
105Date:		January 2009
106Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
107Description:
108		Writing a non-zero value to this attribute will
109		force a rescan of the device's parent bus and all
110		child buses, and re-discover devices removed earlier
111		from this part of the device tree.
112		Depends on CONFIG_HOTPLUG.
113
114What:		/sys/bus/pci/devices/.../reset
115Date:		July 2009
116Contact:	Michael S. Tsirkin <mst@redhat.com>
117Description:
118		Some devices allow an individual function to be reset
119		without affecting other functions in the same device.
120		For devices that have this support, a file named reset
121		will be present in sysfs.  Writing 1 to this file
122		will perform reset.
123
124What:		/sys/bus/pci/devices/.../vpd
125Date:		February 2008
126Contact:	Ben Hutchings <bhutchings@solarflare.com>
127Description:
128		A file named vpd in a device directory will be a
129		binary file containing the Vital Product Data for the
130		device.  It should follow the VPD format defined in
131		PCI Specification 2.1 or 2.2, but users should consider
132		that some devices may have malformatted data.  If the
133		underlying VPD has a writable section then the
134		corresponding section of this file will be writable.
135
136What:		/sys/bus/pci/devices/.../virtfnN
137Date:		March 2009
138Contact:	Yu Zhao <yu.zhao@intel.com>
139Description:
140		This symbolic link appears when hardware supports the SR-IOV
141		capability and the Physical Function driver has enabled it.
142		The symbolic link points to the PCI device sysfs entry of the
143		Virtual Function whose index is N (0...MaxVFs-1).
144
145What:		/sys/bus/pci/devices/.../dep_link
146Date:		March 2009
147Contact:	Yu Zhao <yu.zhao@intel.com>
148Description:
149		This symbolic link appears when hardware supports the SR-IOV
150		capability and the Physical Function driver has enabled it,
151		and this device has vendor specific dependencies with others.
152		The symbolic link points to the PCI device sysfs entry of
153		Physical Function this device depends on.
154
155What:		/sys/bus/pci/devices/.../physfn
156Date:		March 2009
157Contact:	Yu Zhao <yu.zhao@intel.com>
158Description:
159		This symbolic link appears when a device is a Virtual Function.
160		The symbolic link points to the PCI device sysfs entry of the
161		Physical Function this device associates with.
162
163What:		/sys/bus/pci/slots/.../module
164Date:		June 2009
165Contact:	linux-pci@vger.kernel.org
166Description:
167		This symbolic link points to the PCI hotplug controller driver
168		module that manages the hotplug slot.
169
170What:		/sys/bus/pci/devices/.../label
171Date:		July 2010
172Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
173Description:
174		Reading this attribute will provide the firmware
175		given name (SMBIOS type 41 string or ACPI _DSM string) of
176		the PCI device.	The attribute will be created only
177		if the firmware	has given a name to the PCI device.
178		ACPI _DSM string name will be given priority if the
179		system firmware provides SMBIOS type 41 string also.
180Users:
181		Userspace applications interested in knowing the
182		firmware assigned name of the PCI device.
183
184What:		/sys/bus/pci/devices/.../index
185Date:		July 2010
186Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
187Description:
188		Reading this attribute will provide the firmware
189		given instance (SMBIOS type 41 device type instance) of the
190		PCI device. The attribute will be created only if the firmware
191		has given an instance number to the PCI device.
192Users:
193		Userspace applications interested in knowing the
194		firmware assigned device type instance of the PCI
195		device that can help in understanding the firmware
196		intended order of the PCI device.
197
198What:		/sys/bus/pci/devices/.../acpi_index
199Date:		July 2010
200Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
201Description:
202		Reading this attribute will provide the firmware
203		given instance (ACPI _DSM instance number) of the PCI device.
204		The attribute will be created only if the firmware has given
205		an instance number to the PCI device. ACPI _DSM instance number
206		will be given priority if the system firmware provides SMBIOS
207		type 41 device type instance also.
208Users:
209		Userspace applications interested in knowing the
210		firmware assigned instance number of the PCI
211		device that can help in understanding the firmware
212		intended order of the PCI device.
213
214What:		/sys/bus/pci/devices/.../d3cold_allowed
215Date:		July 2012
216Contact:	Huang Ying <ying.huang@intel.com>
217Description:
218		d3cold_allowed is bit to control whether the corresponding PCI
219		device can be put into D3Cold state.  If it is cleared, the
220		device will never be put into D3Cold state.  If it is set, the
221		device may be put into D3Cold state if other requirements are
222		satisfied too.  Reading this attribute will show the current
223		value of d3cold_allowed bit.  Writing this attribute will set
224		the value of d3cold_allowed bit.
225
226What:		/sys/bus/pci/devices/.../sriov_totalvfs
227Date:		November 2012
228Contact:	Donald Dutile <ddutile@redhat.com>
229Description:
230		This file appears when a physical PCIe device supports SR-IOV.
231		Userspace applications can read this file to determine the
232		maximum number of Virtual Functions (VFs) a PCIe physical
233		function (PF) can support. Typically, this is the value reported
234		in the PF's SR-IOV extended capability structure's TotalVFs
235		element.  Drivers have the ability at probe time to reduce the
236		value read from this file via the pci_sriov_set_totalvfs()
237		function.
238
239What:		/sys/bus/pci/devices/.../sriov_numvfs
240Date:		November 2012
241Contact:	Donald Dutile <ddutile@redhat.com>
242Description:
243		This file appears when a physical PCIe device supports SR-IOV.
244		Userspace applications can read and write to this file to
245		determine and control the enablement or disablement of Virtual
246		Functions (VFs) on the physical function (PF). A read of this
247		file will return the number of VFs that are enabled on this PF.
248		A number written to this file will enable the specified
249		number of VFs. A userspace application would typically read the
250		file and check that the value is zero, and then write the number
251		of VFs that should be enabled on the PF; the value written
252		should be less than or equal to the value in the sriov_totalvfs
253		file. A userspace application wanting to disable the VFs would
254		write a zero to this file. The core ensures that valid values
255		are written to this file, and returns errors when values are not
256		valid.  For example, writing a 2 to this file when sriov_numvfs
257		is not 0 and not 2 already will return an error. Writing a 10
258		when the value of sriov_totalvfs is 8 will return an error.
259