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_irqs/ 69Date: September, 2011 70Contact: Neil Horman <nhorman@tuxdriver.com> 71Description: 72 The /sys/devices/.../msi_irqs directory contains a variable set 73 of files, with each file being named after a corresponding msi 74 irq vector allocated to that device. 75 76What: /sys/bus/pci/devices/.../msi_irqs/<N> 77Date: September 2011 78Contact: Neil Horman <nhorman@tuxdriver.com> 79Description: 80 This attribute indicates the mode that the irq vector named by 81 the file is in (msi vs. msix) 82 83What: /sys/bus/pci/devices/.../remove 84Date: January 2009 85Contact: Linux PCI developers <linux-pci@vger.kernel.org> 86Description: 87 Writing a non-zero value to this attribute will 88 hot-remove the PCI device and any of its children. 89 90What: /sys/bus/pci/devices/.../pci_bus/.../rescan 91Date: May 2011 92Contact: Linux PCI developers <linux-pci@vger.kernel.org> 93Description: 94 Writing a non-zero value to this attribute will 95 force a rescan of the bus and all child buses, 96 and re-discover devices removed earlier from this 97 part of the device tree. 98 99What: /sys/bus/pci/devices/.../rescan 100Date: January 2009 101Contact: Linux PCI developers <linux-pci@vger.kernel.org> 102Description: 103 Writing a non-zero value to this attribute will 104 force a rescan of the device's parent bus and all 105 child buses, and re-discover devices removed earlier 106 from this part of the device tree. 107 108What: /sys/bus/pci/devices/.../reset 109Date: July 2009 110Contact: Michael S. Tsirkin <mst@redhat.com> 111Description: 112 Some devices allow an individual function to be reset 113 without affecting other functions in the same device. 114 For devices that have this support, a file named reset 115 will be present in sysfs. Writing 1 to this file 116 will perform reset. 117 118What: /sys/bus/pci/devices/.../vpd 119Date: February 2008 120Contact: Ben Hutchings <bwh@kernel.org> 121Description: 122 A file named vpd in a device directory will be a 123 binary file containing the Vital Product Data for the 124 device. It should follow the VPD format defined in 125 PCI Specification 2.1 or 2.2, but users should consider 126 that some devices may have malformatted data. If the 127 underlying VPD has a writable section then the 128 corresponding section of this file will be writable. 129 130What: /sys/bus/pci/devices/.../virtfnN 131Date: March 2009 132Contact: Yu Zhao <yu.zhao@intel.com> 133Description: 134 This symbolic link appears when hardware supports the SR-IOV 135 capability and the Physical Function driver has enabled it. 136 The symbolic link points to the PCI device sysfs entry of the 137 Virtual Function whose index is N (0...MaxVFs-1). 138 139What: /sys/bus/pci/devices/.../dep_link 140Date: March 2009 141Contact: Yu Zhao <yu.zhao@intel.com> 142Description: 143 This symbolic link appears when hardware supports the SR-IOV 144 capability and the Physical Function driver has enabled it, 145 and this device has vendor specific dependencies with others. 146 The symbolic link points to the PCI device sysfs entry of 147 Physical Function this device depends on. 148 149What: /sys/bus/pci/devices/.../physfn 150Date: March 2009 151Contact: Yu Zhao <yu.zhao@intel.com> 152Description: 153 This symbolic link appears when a device is a Virtual Function. 154 The symbolic link points to the PCI device sysfs entry of the 155 Physical Function this device associates with. 156 157What: /sys/bus/pci/slots/.../module 158Date: June 2009 159Contact: linux-pci@vger.kernel.org 160Description: 161 This symbolic link points to the PCI hotplug controller driver 162 module that manages the hotplug slot. 163 164What: /sys/bus/pci/devices/.../label 165Date: July 2010 166Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com 167Description: 168 Reading this attribute will provide the firmware 169 given name (SMBIOS type 41 string or ACPI _DSM string) of 170 the PCI device. The attribute will be created only 171 if the firmware has given a name to the PCI device. 172 ACPI _DSM string name will be given priority if the 173 system firmware provides SMBIOS type 41 string also. 174Users: 175 Userspace applications interested in knowing the 176 firmware assigned name of the PCI device. 177 178What: /sys/bus/pci/devices/.../index 179Date: July 2010 180Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com 181Description: 182 Reading this attribute will provide the firmware 183 given instance (SMBIOS type 41 device type instance) of the 184 PCI device. The attribute will be created only if the firmware 185 has given an instance number to the PCI device. 186Users: 187 Userspace applications interested in knowing the 188 firmware assigned device type instance of the PCI 189 device that can help in understanding the firmware 190 intended order of the PCI device. 191 192What: /sys/bus/pci/devices/.../acpi_index 193Date: July 2010 194Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com 195Description: 196 Reading this attribute will provide the firmware 197 given instance (ACPI _DSM instance number) of the PCI device. 198 The attribute will be created only if the firmware has given 199 an instance number to the PCI device. ACPI _DSM instance number 200 will be given priority if the system firmware provides SMBIOS 201 type 41 device type instance also. 202Users: 203 Userspace applications interested in knowing the 204 firmware assigned instance number 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/.../d3cold_allowed 209Date: July 2012 210Contact: Huang Ying <ying.huang@intel.com> 211Description: 212 d3cold_allowed is bit to control whether the corresponding PCI 213 device can be put into D3Cold state. If it is cleared, the 214 device will never be put into D3Cold state. If it is set, the 215 device may be put into D3Cold state if other requirements are 216 satisfied too. Reading this attribute will show the current 217 value of d3cold_allowed bit. Writing this attribute will set 218 the value of d3cold_allowed bit. 219 220What: /sys/bus/pci/devices/.../sriov_totalvfs 221Date: November 2012 222Contact: Donald Dutile <ddutile@redhat.com> 223Description: 224 This file appears when a physical PCIe device supports SR-IOV. 225 Userspace applications can read this file to determine the 226 maximum number of Virtual Functions (VFs) a PCIe physical 227 function (PF) can support. Typically, this is the value reported 228 in the PF's SR-IOV extended capability structure's TotalVFs 229 element. Drivers have the ability at probe time to reduce the 230 value read from this file via the pci_sriov_set_totalvfs() 231 function. 232 233What: /sys/bus/pci/devices/.../sriov_numvfs 234Date: November 2012 235Contact: Donald Dutile <ddutile@redhat.com> 236Description: 237 This file appears when a physical PCIe device supports SR-IOV. 238 Userspace applications can read and write to this file to 239 determine and control the enablement or disablement of Virtual 240 Functions (VFs) on the physical function (PF). A read of this 241 file will return the number of VFs that are enabled on this PF. 242 A number written to this file will enable the specified 243 number of VFs. A userspace application would typically read the 244 file and check that the value is zero, and then write the number 245 of VFs that should be enabled on the PF; the value written 246 should be less than or equal to the value in the sriov_totalvfs 247 file. A userspace application wanting to disable the VFs would 248 write a zero to this file. The core ensures that valid values 249 are written to this file, and returns errors when values are not 250 valid. For example, writing a 2 to this file when sriov_numvfs 251 is not 0 and not 2 already will return an error. Writing a 10 252 when the value of sriov_totalvfs is 8 will return an error. 253 254What: /sys/bus/pci/devices/.../driver_override 255Date: April 2014 256Contact: Alex Williamson <alex.williamson@redhat.com> 257Description: 258 This file allows the driver for a device to be specified which 259 will override standard static and dynamic ID matching. When 260 specified, only a driver with a name matching the value written 261 to driver_override will have an opportunity to bind to the 262 device. The override is specified by writing a string to the 263 driver_override file (echo pci-stub > driver_override) and 264 may be cleared with an empty string (echo > driver_override). 265 This returns the device to standard matching rules binding. 266 Writing to driver_override does not automatically unbind the 267 device from its current driver or make any attempt to 268 automatically load the specified driver. If no driver with a 269 matching name is currently loaded in the kernel, the device 270 will not bind to any driver. This also allows devices to 271 opt-out of driver binding using a driver_override name such as 272 "none". Only a single driver may be specified in the override, 273 there is no support for parsing delimiters. 274