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 12 # echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/bind 13 14 (Note: kernels before 2.6.28 may require echo -n). 15 16What: /sys/bus/pci/drivers/.../unbind 17Date: December 2003 18Contact: linux-pci@vger.kernel.org 19Description: 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:: 26 27 # echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/unbind 28 29 (Note: kernels before 2.6.28 may require echo -n). 30 31What: /sys/bus/pci/drivers/.../new_id 32Date: December 2003 33Contact: linux-pci@vger.kernel.org 34Description: 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:: 46 47 # echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_id 48 49What: /sys/bus/pci/drivers/.../remove_id 50Date: February 2009 51Contact: Chris Wright <chrisw@sous-sol.org> 52Description: 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:: 63 64 # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id 65 66What: /sys/bus/pci/rescan 67Date: January 2009 68Contact: Linux PCI developers <linux-pci@vger.kernel.org> 69Description: 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. 73 74What: /sys/bus/pci/devices/.../msi_bus 75Date: September 2014 76Contact: Linux PCI developers <linux-pci@vger.kernel.org> 77Description: 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. 83 84What: /sys/bus/pci/devices/.../msi_irqs/ 85Date: September, 2011 86Contact: Neil Horman <nhorman@tuxdriver.com> 87Description: 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. 91 92What: /sys/bus/pci/devices/.../msi_irqs/<N> 93Date: September 2011 94Contact: Neil Horman <nhorman@tuxdriver.com> 95Description: 96 This attribute indicates the mode that the irq vector named by 97 the file is in (msi vs. msix) 98 99What: /sys/bus/pci/devices/.../remove 100Date: January 2009 101Contact: Linux PCI developers <linux-pci@vger.kernel.org> 102Description: 103 Writing a non-zero value to this attribute will 104 hot-remove the PCI device and any of its children. 105 106What: /sys/bus/pci/devices/.../pci_bus/.../rescan 107Date: May 2011 108Contact: Linux PCI developers <linux-pci@vger.kernel.org> 109Description: 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. 114 115What: /sys/bus/pci/devices/.../rescan 116Date: January 2009 117Contact: Linux PCI developers <linux-pci@vger.kernel.org> 118Description: 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. 123 124What: /sys/bus/pci/devices/.../reset 125Date: July 2009 126Contact: Michael S. Tsirkin <mst@redhat.com> 127Description: 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 132 will perform reset. 133 134What: /sys/bus/pci/devices/.../vpd 135Date: February 2008 136Contact: Ben Hutchings <bwh@kernel.org> 137Description: 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 malformatted data. If the 143 underlying VPD has a writable section then the 144 corresponding section of this file will be writable. 145 146What: /sys/bus/pci/devices/.../virtfnN 147Date: March 2009 148Contact: Yu Zhao <yu.zhao@intel.com> 149Description: 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). 154 155What: /sys/bus/pci/devices/.../dep_link 156Date: March 2009 157Contact: Yu Zhao <yu.zhao@intel.com> 158Description: 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. 164 165What: /sys/bus/pci/devices/.../physfn 166Date: March 2009 167Contact: Yu Zhao <yu.zhao@intel.com> 168Description: 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. 172 173What: /sys/bus/pci/slots/.../module 174Date: June 2009 175Contact: linux-pci@vger.kernel.org 176Description: 177 This symbolic link points to the PCI hotplug controller driver 178 module that manages the hotplug slot. 179 180What: /sys/bus/pci/devices/.../label 181Date: July 2010 182Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com 183Description: 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. 190Users: 191 Userspace applications interested in knowing the 192 firmware assigned name of the PCI device. 193 194What: /sys/bus/pci/devices/.../index 195Date: July 2010 196Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com 197Description: 198 Reading this attribute will provide the firmware 199 given instance (SMBIOS type 41 device type instance) of the 200 PCI device. The attribute will be created only if the firmware 201 has given an instance number to the PCI device. 202Users: 203 Userspace applications interested in knowing the 204 firmware assigned device type instance of the PCI 205 device that can help in understanding the firmware 206 intended order of the PCI device. 207 208What: /sys/bus/pci/devices/.../acpi_index 209Date: July 2010 210Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com 211Description: 212 Reading this attribute will provide the firmware 213 given instance (ACPI _DSM instance number) of the PCI device. 214 The attribute will be created only if the firmware has given 215 an instance number to the PCI device. ACPI _DSM instance number 216 will be given priority if the system firmware provides SMBIOS 217 type 41 device type instance also. 218Users: 219 Userspace applications interested in knowing the 220 firmware assigned instance number of the PCI 221 device that can help in understanding the firmware 222 intended order of the PCI device. 223 224What: /sys/bus/pci/devices/.../d3cold_allowed 225Date: July 2012 226Contact: Huang Ying <ying.huang@intel.com> 227Description: 228 d3cold_allowed is bit to control whether the corresponding PCI 229 device can be put into D3Cold state. If it is cleared, the 230 device will never be put into D3Cold state. If it is set, the 231 device may be put into D3Cold state if other requirements are 232 satisfied too. Reading this attribute will show the current 233 value of d3cold_allowed bit. Writing this attribute will set 234 the value of d3cold_allowed bit. 235 236What: /sys/bus/pci/devices/.../sriov_totalvfs 237Date: November 2012 238Contact: Donald Dutile <ddutile@redhat.com> 239Description: 240 This file appears when a physical PCIe device supports SR-IOV. 241 Userspace applications can read this file to determine the 242 maximum number of Virtual Functions (VFs) a PCIe physical 243 function (PF) can support. Typically, this is the value reported 244 in the PF's SR-IOV extended capability structure's TotalVFs 245 element. Drivers have the ability at probe time to reduce the 246 value read from this file via the pci_sriov_set_totalvfs() 247 function. 248 249What: /sys/bus/pci/devices/.../sriov_numvfs 250Date: November 2012 251Contact: Donald Dutile <ddutile@redhat.com> 252Description: 253 This file appears when a physical PCIe device supports SR-IOV. 254 Userspace applications can read and write to this file to 255 determine and control the enablement or disablement of Virtual 256 Functions (VFs) on the physical function (PF). A read of this 257 file will return the number of VFs that are enabled on this PF. 258 A number written to this file will enable the specified 259 number of VFs. A userspace application would typically read the 260 file and check that the value is zero, and then write the number 261 of VFs that should be enabled on the PF; the value written 262 should be less than or equal to the value in the sriov_totalvfs 263 file. A userspace application wanting to disable the VFs would 264 write a zero to this file. The core ensures that valid values 265 are written to this file, and returns errors when values are not 266 valid. For example, writing a 2 to this file when sriov_numvfs 267 is not 0 and not 2 already will return an error. Writing a 10 268 when the value of sriov_totalvfs is 8 will return an error. 269 270What: /sys/bus/pci/devices/.../driver_override 271Date: April 2014 272Contact: Alex Williamson <alex.williamson@redhat.com> 273Description: 274 This file allows the driver for a device to be specified which 275 will override standard static and dynamic ID matching. When 276 specified, only a driver with a name matching the value written 277 to driver_override will have an opportunity to bind to the 278 device. The override is specified by writing a string to the 279 driver_override file (echo pci-stub > driver_override) and 280 may be cleared with an empty string (echo > driver_override). 281 This returns the device to standard matching rules binding. 282 Writing to driver_override does not automatically unbind the 283 device from its current driver or make any attempt to 284 automatically load the specified driver. If no driver with a 285 matching name is currently loaded in the kernel, the device 286 will not bind to any driver. This also allows devices to 287 opt-out of driver binding using a driver_override name such as 288 "none". Only a single driver may be specified in the override, 289 there is no support for parsing delimiters. 290 291What: /sys/bus/pci/devices/.../numa_node 292Date: Oct 2014 293Contact: Prarit Bhargava <prarit@redhat.com> 294Description: 295 This file contains the NUMA node to which the PCI device is 296 attached, or -1 if the node is unknown. The initial value 297 comes from an ACPI _PXM method or a similar firmware 298 source. If that is missing or incorrect, this file can be 299 written to override the node. In that case, please report 300 a firmware bug to the system vendor. Writing to this file 301 taints the kernel with TAINT_FIRMWARE_WORKAROUND, which 302 reduces the supportability of your system. 303 304What: /sys/bus/pci/devices/.../revision 305Date: November 2016 306Contact: Emil Velikov <emil.l.velikov@gmail.com> 307Description: 308 This file contains the revision field of the PCI device. 309 The value comes from device config space. The file is read only. 310 311What: /sys/bus/pci/devices/.../sriov_drivers_autoprobe 312Date: April 2017 313Contact: Bodong Wang<bodong@mellanox.com> 314Description: 315 This file is associated with the PF of a device that 316 supports SR-IOV. It determines whether newly-enabled VFs 317 are immediately bound to a driver. It initially contains 318 1, which means the kernel automatically binds VFs to a 319 compatible driver immediately after they are enabled. If 320 an application writes 0 to the file before enabling VFs, 321 the kernel will not bind VFs to a driver. 322 323 A typical use case is to write 0 to this file, then enable 324 VFs, then assign the newly-created VFs to virtual machines. 325 Note that changing this file does not affect already- 326 enabled VFs. In this scenario, the user must first disable 327 the VFs, write 0 to sriov_drivers_autoprobe, then re-enable 328 the VFs. 329 330 This is similar to /sys/bus/pci/drivers_autoprobe, but 331 affects only the VFs associated with a specific PF. 332 333What: /sys/bus/pci/devices/.../p2pmem/size 334Date: November 2017 335Contact: Logan Gunthorpe <logang@deltatee.com> 336Description: 337 If the device has any Peer-to-Peer memory registered, this 338 file contains the total amount of memory that the device 339 provides (in decimal). 340 341What: /sys/bus/pci/devices/.../p2pmem/available 342Date: November 2017 343Contact: Logan Gunthorpe <logang@deltatee.com> 344Description: 345 If the device has any Peer-to-Peer memory registered, this 346 file contains the amount of memory that has not been 347 allocated (in decimal). 348 349What: /sys/bus/pci/devices/.../p2pmem/published 350Date: November 2017 351Contact: Logan Gunthorpe <logang@deltatee.com> 352Description: 353 If the device has any Peer-to-Peer memory registered, this 354 file contains a '1' if the memory has been published for 355 use outside the driver that owns the device. 356 357What: /sys/bus/pci/devices/.../link/clkpm 358 /sys/bus/pci/devices/.../link/l0s_aspm 359 /sys/bus/pci/devices/.../link/l1_aspm 360 /sys/bus/pci/devices/.../link/l1_1_aspm 361 /sys/bus/pci/devices/.../link/l1_2_aspm 362 /sys/bus/pci/devices/.../link/l1_1_pcipm 363 /sys/bus/pci/devices/.../link/l1_2_pcipm 364Date: October 2019 365Contact: Heiner Kallweit <hkallweit1@gmail.com> 366Description: If ASPM is supported for an endpoint, these files can be 367 used to disable or enable the individual power management 368 states. Write y/1/on to enable, n/0/off to disable. 369 370What: /sys/bus/pci/devices/.../power_state 371Date: November 2020 372Contact: Linux PCI developers <linux-pci@vger.kernel.org> 373Description: 374 This file contains the current PCI power state of the device. 375 The value comes from the PCI kernel device state and can be one 376 of: "unknown", "error", "D0", D1", "D2", "D3hot", "D3cold". 377 The file is read only. 378