1 What: /sys/bus/pci/drivers/.../bind
3 Contact: linux-pci@vger.kernel.org
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::
12 # echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/bind
14 (Note: kernels before 2.6.28 may require echo -n).
16 What: /sys/bus/pci/drivers/.../unbind
18 Contact: linux-pci@vger.kernel.org
20 Writing a device location to this file will cause the
21 driver to attempt to unbind from the device found at
22 this location. This may be useful when overriding default
23 bindings. The format for the location is: DDDD:BB:DD.F.
24 That is Domain:Bus:Device.Function and is the same as
25 found in /sys/bus/pci/devices/. For example::
27 # echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/unbind
29 (Note: kernels before 2.6.28 may require echo -n).
31 What: /sys/bus/pci/drivers/.../new_id
33 Contact: linux-pci@vger.kernel.org
35 Writing a device ID to this file will attempt to
36 dynamically add a new device ID to a PCI device driver.
37 This may allow the driver to support more hardware than
38 was included in the driver's static device ID support
39 table at compile time. The format for the device ID is:
40 VVVV DDDD SVVV SDDD CCCC MMMM PPPP. That is Vendor ID,
41 Device ID, Subsystem Vendor ID, Subsystem Device ID,
42 Class, Class Mask, and Private Driver Data. The Vendor ID
43 and Device ID fields are required, the rest are optional.
44 Upon successfully adding an ID, the driver will probe
45 for the device and attempt to bind to it. For example::
47 # echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_id
49 What: /sys/bus/pci/drivers/.../remove_id
51 Contact: Chris Wright <chrisw@sous-sol.org>
53 Writing a device ID to this file will remove an ID
54 that was dynamically added via the new_id sysfs entry.
55 The format for the device ID is:
56 VVVV DDDD SVVV SDDD CCCC MMMM. That is Vendor ID, Device
57 ID, Subsystem Vendor ID, Subsystem Device ID, Class,
58 and Class Mask. The Vendor ID and Device ID fields are
59 required, the rest are optional. After successfully
60 removing an ID, the driver will no longer support the
61 device. This is useful to ensure auto probing won't
62 match the driver to the device. For example::
64 # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id
66 What: /sys/bus/pci/rescan
68 Contact: Linux PCI developers <linux-pci@vger.kernel.org>
70 Writing a non-zero value to this attribute will
71 force a rescan of all PCI buses in the system, and
72 re-discover previously removed devices.
74 What: /sys/bus/pci/devices/.../msi_bus
76 Contact: Linux PCI developers <linux-pci@vger.kernel.org>
78 Writing a zero value to this attribute disallows MSI and
79 MSI-X for any future drivers of the device. If the device
80 is a bridge, MSI and MSI-X will be disallowed for future
81 drivers of all child devices under the bridge. Drivers
82 must be reloaded for the new setting to take effect.
84 What: /sys/bus/pci/devices/.../msi_irqs/
86 Contact: Neil Horman <nhorman@tuxdriver.com>
88 The /sys/devices/.../msi_irqs directory contains a variable set
89 of files, with each file being named after a corresponding msi
90 irq vector allocated to that device.
92 What: /sys/bus/pci/devices/.../msi_irqs/<N>
94 Contact: Neil Horman <nhorman@tuxdriver.com>
96 This attribute indicates the mode that the irq vector named by
97 the file is in (msi vs. msix)
99 What: /sys/bus/pci/devices/.../remove
101 Contact: Linux PCI developers <linux-pci@vger.kernel.org>
103 Writing a non-zero value to this attribute will
104 hot-remove the PCI device and any of its children.
106 What: /sys/bus/pci/devices/.../pci_bus/.../rescan
108 Contact: Linux PCI developers <linux-pci@vger.kernel.org>
110 Writing a non-zero value to this attribute will
111 force a rescan of the bus and all child buses,
112 and re-discover devices removed earlier from this
113 part of the device tree.
115 What: /sys/bus/pci/devices/.../rescan
117 Contact: Linux PCI developers <linux-pci@vger.kernel.org>
119 Writing a non-zero value to this attribute will
120 force a rescan of the device's parent bus and all
121 child buses, and re-discover devices removed earlier
122 from this part of the device tree.
124 What: /sys/bus/pci/devices/.../reset
126 Contact: Michael S. Tsirkin <mst@redhat.com>
128 Some devices allow an individual function to be reset
129 without affecting other functions in the same device.
130 For devices that have this support, a file named reset
131 will be present in sysfs. Writing 1 to this file
134 What: /sys/bus/pci/devices/.../vpd
136 Contact: Ben Hutchings <bwh@kernel.org>
138 A file named vpd in a device directory will be a
139 binary file containing the Vital Product Data for the
140 device. It should follow the VPD format defined in
141 PCI Specification 2.1 or 2.2, but users should consider
142 that some devices may have incorrectly formatted data.
143 If the underlying VPD has a writable section then the
144 corresponding section of this file will be writable.
146 What: /sys/bus/pci/devices/.../virtfnN
148 Contact: Yu Zhao <yu.zhao@intel.com>
150 This symbolic link appears when hardware supports the SR-IOV
151 capability and the Physical Function driver has enabled it.
152 The symbolic link points to the PCI device sysfs entry of the
153 Virtual Function whose index is N (0...MaxVFs-1).
155 What: /sys/bus/pci/devices/.../dep_link
157 Contact: Yu Zhao <yu.zhao@intel.com>
159 This symbolic link appears when hardware supports the SR-IOV
160 capability and the Physical Function driver has enabled it,
161 and this device has vendor specific dependencies with others.
162 The symbolic link points to the PCI device sysfs entry of
163 Physical Function this device depends on.
165 What: /sys/bus/pci/devices/.../physfn
167 Contact: Yu Zhao <yu.zhao@intel.com>
169 This symbolic link appears when a device is a Virtual Function.
170 The symbolic link points to the PCI device sysfs entry of the
171 Physical Function this device associates with.
173 What: /sys/bus/pci/slots/.../module
175 Contact: linux-pci@vger.kernel.org
177 This symbolic link points to the PCI hotplug controller driver
178 module that manages the hotplug slot.
180 What: /sys/bus/pci/devices/.../label
182 Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
184 Reading this attribute will provide the firmware
185 given name (SMBIOS type 41 string or ACPI _DSM string) of
186 the PCI device. The attribute will be created only
187 if the firmware has given a name to the PCI device.
188 ACPI _DSM string name will be given priority if the
189 system firmware provides SMBIOS type 41 string also.
191 Userspace applications interested in knowing the
192 firmware assigned name of the PCI device.
194 What: /sys/bus/pci/devices/.../index
196 Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
198 Reading this attribute will provide the firmware given instance
199 number of the PCI device. Depending on the platform this can
200 be for example the SMBIOS type 41 device type instance or the
201 user-defined ID (UID) on s390. The attribute will be created
202 only if the firmware has given an instance number to the PCI
203 device and that number is guaranteed to uniquely identify the
204 device in the system.
206 Userspace applications interested in knowing the
207 firmware assigned device type instance of the PCI
208 device that can help in understanding the firmware
209 intended order of the PCI device.
211 What: /sys/bus/pci/devices/.../acpi_index
213 Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
215 Reading this attribute will provide the firmware
216 given instance (ACPI _DSM instance number) of the PCI device.
217 The attribute will be created only if the firmware has given
218 an instance number to the PCI device. ACPI _DSM instance number
219 will be given priority if the system firmware provides SMBIOS
220 type 41 device type instance also.
222 Userspace applications interested in knowing the
223 firmware assigned instance number of the PCI
224 device that can help in understanding the firmware
225 intended order of the PCI device.
227 What: /sys/bus/pci/devices/.../d3cold_allowed
229 Contact: Huang Ying <ying.huang@intel.com>
231 d3cold_allowed is bit to control whether the corresponding PCI
232 device can be put into D3Cold state. If it is cleared, the
233 device will never be put into D3Cold state. If it is set, the
234 device may be put into D3Cold state if other requirements are
235 satisfied too. Reading this attribute will show the current
236 value of d3cold_allowed bit. Writing this attribute will set
237 the value of d3cold_allowed bit.
239 What: /sys/bus/pci/devices/.../sriov_totalvfs
241 Contact: Donald Dutile <ddutile@redhat.com>
243 This file appears when a physical PCIe device supports SR-IOV.
244 Userspace applications can read this file to determine the
245 maximum number of Virtual Functions (VFs) a PCIe physical
246 function (PF) can support. Typically, this is the value reported
247 in the PF's SR-IOV extended capability structure's TotalVFs
248 element. Drivers have the ability at probe time to reduce the
249 value read from this file via the pci_sriov_set_totalvfs()
252 What: /sys/bus/pci/devices/.../sriov_numvfs
254 Contact: Donald Dutile <ddutile@redhat.com>
256 This file appears when a physical PCIe device supports SR-IOV.
257 Userspace applications can read and write to this file to
258 determine and control the enablement or disablement of Virtual
259 Functions (VFs) on the physical function (PF). A read of this
260 file will return the number of VFs that are enabled on this PF.
261 A number written to this file will enable the specified
262 number of VFs. A userspace application would typically read the
263 file and check that the value is zero, and then write the number
264 of VFs that should be enabled on the PF; the value written
265 should be less than or equal to the value in the sriov_totalvfs
266 file. A userspace application wanting to disable the VFs would
267 write a zero to this file. The core ensures that valid values
268 are written to this file, and returns errors when values are not
269 valid. For example, writing a 2 to this file when sriov_numvfs
270 is not 0 and not 2 already will return an error. Writing a 10
271 when the value of sriov_totalvfs is 8 will return an error.
273 What: /sys/bus/pci/devices/.../driver_override
275 Contact: Alex Williamson <alex.williamson@redhat.com>
277 This file allows the driver for a device to be specified which
278 will override standard static and dynamic ID matching. When
279 specified, only a driver with a name matching the value written
280 to driver_override will have an opportunity to bind to the
281 device. The override is specified by writing a string to the
282 driver_override file (echo pci-stub > driver_override) and
283 may be cleared with an empty string (echo > driver_override).
284 This returns the device to standard matching rules binding.
285 Writing to driver_override does not automatically unbind the
286 device from its current driver or make any attempt to
287 automatically load the specified driver. If no driver with a
288 matching name is currently loaded in the kernel, the device
289 will not bind to any driver. This also allows devices to
290 opt-out of driver binding using a driver_override name such as
291 "none". Only a single driver may be specified in the override,
292 there is no support for parsing delimiters.
294 What: /sys/bus/pci/devices/.../numa_node
296 Contact: Prarit Bhargava <prarit@redhat.com>
298 This file contains the NUMA node to which the PCI device is
299 attached, or -1 if the node is unknown. The initial value
300 comes from an ACPI _PXM method or a similar firmware
301 source. If that is missing or incorrect, this file can be
302 written to override the node. In that case, please report
303 a firmware bug to the system vendor. Writing to this file
304 taints the kernel with TAINT_FIRMWARE_WORKAROUND, which
305 reduces the supportability of your system.
307 What: /sys/bus/pci/devices/.../revision
309 Contact: Emil Velikov <emil.l.velikov@gmail.com>
311 This file contains the revision field of the PCI device.
312 The value comes from device config space. The file is read only.
314 What: /sys/bus/pci/devices/.../sriov_drivers_autoprobe
316 Contact: Bodong Wang<bodong@mellanox.com>
318 This file is associated with the PF of a device that
319 supports SR-IOV. It determines whether newly-enabled VFs
320 are immediately bound to a driver. It initially contains
321 1, which means the kernel automatically binds VFs to a
322 compatible driver immediately after they are enabled. If
323 an application writes 0 to the file before enabling VFs,
324 the kernel will not bind VFs to a driver.
326 A typical use case is to write 0 to this file, then enable
327 VFs, then assign the newly-created VFs to virtual machines.
328 Note that changing this file does not affect already-
329 enabled VFs. In this scenario, the user must first disable
330 the VFs, write 0 to sriov_drivers_autoprobe, then re-enable
333 This is similar to /sys/bus/pci/drivers_autoprobe, but
334 affects only the VFs associated with a specific PF.
336 What: /sys/bus/pci/devices/.../p2pmem/size
338 Contact: Logan Gunthorpe <logang@deltatee.com>
340 If the device has any Peer-to-Peer memory registered, this
341 file contains the total amount of memory that the device
342 provides (in decimal).
344 What: /sys/bus/pci/devices/.../p2pmem/available
346 Contact: Logan Gunthorpe <logang@deltatee.com>
348 If the device has any Peer-to-Peer memory registered, this
349 file contains the amount of memory that has not been
350 allocated (in decimal).
352 What: /sys/bus/pci/devices/.../p2pmem/published
354 Contact: Logan Gunthorpe <logang@deltatee.com>
356 If the device has any Peer-to-Peer memory registered, this
357 file contains a '1' if the memory has been published for
358 use outside the driver that owns the device.
360 What: /sys/bus/pci/devices/.../link/clkpm
361 /sys/bus/pci/devices/.../link/l0s_aspm
362 /sys/bus/pci/devices/.../link/l1_aspm
363 /sys/bus/pci/devices/.../link/l1_1_aspm
364 /sys/bus/pci/devices/.../link/l1_2_aspm
365 /sys/bus/pci/devices/.../link/l1_1_pcipm
366 /sys/bus/pci/devices/.../link/l1_2_pcipm
368 Contact: Heiner Kallweit <hkallweit1@gmail.com>
369 Description: If ASPM is supported for an endpoint, these files can be
370 used to disable or enable the individual power management
371 states. Write y/1/on to enable, n/0/off to disable.
373 What: /sys/bus/pci/devices/.../power_state
375 Contact: Linux PCI developers <linux-pci@vger.kernel.org>
377 This file contains the current PCI power state of the device.
378 The value comes from the PCI kernel device state and can be one
379 of: "unknown", "error", "D0", D1", "D2", "D3hot", "D3cold".
380 The file is read only.
382 What: /sys/bus/pci/devices/.../sriov_vf_total_msix
384 Contact: Leon Romanovsky <leonro@nvidia.com>
386 This file is associated with a SR-IOV physical function (PF).
387 It contains the total number of MSI-X vectors available for
388 assignment to all virtual functions (VFs) associated with PF.
389 The value will be zero if the device doesn't support this
390 functionality. For supported devices, the value will be
391 constant and won't be changed after MSI-X vectors assignment.
393 What: /sys/bus/pci/devices/.../sriov_vf_msix_count
395 Contact: Leon Romanovsky <leonro@nvidia.com>
397 This file is associated with a SR-IOV virtual function (VF).
398 It allows configuration of the number of MSI-X vectors for
399 the VF. This allows devices that have a global pool of MSI-X
400 vectors to optimally divide them between VFs based on VF usage.
402 The values accepted are:
403 * > 0 - this number will be reported as the Table Size in the
404 VF's MSI-X capability
406 * = 0 - will reset to the device default value
408 The file is writable if the PF is bound to a driver that
409 implements ->sriov_set_msix_vec_count().