xref: /linux/Documentation/ABI/testing/sysfs-bus-pci (revision c34e9ab9a612ee8b18273398ef75c207b01f516d)
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/.../reset_subordinate
167Date:		October 2024
168Contact:	linux-pci@vger.kernel.org
169Description:
170		This is visible only for bridge devices. If you want to reset
171		all devices attached through the subordinate bus of a specific
172		bridge device, writing 1 to this will try to do it.  This will
173		affect all devices attached to the system through this bridge
174		similiar to writing 1 to their individual "reset" file, so use
175		with caution.
176
177What:		/sys/bus/pci/devices/.../vpd
178Date:		February 2008
179Contact:	Ben Hutchings <bwh@kernel.org>
180Description:
181		A file named vpd in a device directory will be a
182		binary file containing the Vital Product Data for the
183		device.  It should follow the VPD format defined in
184		PCI Specification 2.1 or 2.2, but users should consider
185		that some devices may have incorrectly formatted data.
186		If the underlying VPD has a writable section then the
187		corresponding section of this file will be writable.
188
189What:		/sys/bus/pci/devices/.../virtfn<N>
190Date:		March 2009
191Contact:	Yu Zhao <yu.zhao@intel.com>
192Description:
193		This symbolic link appears when hardware supports the SR-IOV
194		capability and the Physical Function driver has enabled it.
195		The symbolic link points to the PCI device sysfs entry of the
196		Virtual Function whose index is N (0...MaxVFs-1).
197
198What:		/sys/bus/pci/devices/.../dep_link
199Date:		March 2009
200Contact:	Yu Zhao <yu.zhao@intel.com>
201Description:
202		This symbolic link appears when hardware supports the SR-IOV
203		capability and the Physical Function driver has enabled it,
204		and this device has vendor specific dependencies with others.
205		The symbolic link points to the PCI device sysfs entry of
206		Physical Function this device depends on.
207
208What:		/sys/bus/pci/devices/.../physfn
209Date:		March 2009
210Contact:	Yu Zhao <yu.zhao@intel.com>
211Description:
212		This symbolic link appears when a device is a Virtual Function.
213		The symbolic link points to the PCI device sysfs entry of the
214		Physical Function this device associates with.
215
216What:		/sys/bus/pci/devices/.../modalias
217Date:		May 2005
218Contact:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
219Description:
220		This attribute indicates the PCI ID of the device object.
221
222		That is in the format:
223		pci:vXXXXXXXXdXXXXXXXXsvXXXXXXXXsdXXXXXXXXbcXXscXXiXX,
224		where:
225
226		    - vXXXXXXXX contains the vendor ID;
227		    - dXXXXXXXX contains the device ID;
228		    - svXXXXXXXX contains the sub-vendor ID;
229		    - sdXXXXXXXX contains the subsystem device ID;
230		    - bcXX contains the device class;
231		    - scXX contains the device subclass;
232		    - iXX contains the device class programming interface.
233
234What:		/sys/bus/pci/slots/.../module
235Date:		June 2009
236Contact:	linux-pci@vger.kernel.org
237Description:
238		This symbolic link points to the PCI hotplug controller driver
239		module that manages the hotplug slot.
240
241What:		/sys/bus/pci/devices/.../label
242Date:		July 2010
243Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
244Description:
245		Reading this attribute will provide the firmware
246		given name (SMBIOS type 41 string or ACPI _DSM string) of
247		the PCI device.	The attribute will be created only
248		if the firmware	has given a name to the PCI device.
249		ACPI _DSM string name will be given priority if the
250		system firmware provides SMBIOS type 41 string also.
251Users:
252		Userspace applications interested in knowing the
253		firmware assigned name of the PCI device.
254
255What:		/sys/bus/pci/devices/.../index
256Date:		July 2010
257Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
258Description:
259		Reading this attribute will provide the firmware given instance
260		number of the PCI device.  Depending on the platform this can
261		be for example the SMBIOS type 41 device type instance or the
262		user-defined ID (UID) on s390. The attribute will be created
263		only if the firmware has given an instance number to the PCI
264		device and that number is guaranteed to uniquely identify the
265		device in the system.
266Users:
267		Userspace applications interested in knowing the
268		firmware assigned device type instance of the PCI
269		device that can help in understanding the firmware
270		intended order of the PCI device.
271
272What:		/sys/bus/pci/devices/.../acpi_index
273Date:		July 2010
274Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
275Description:
276		Reading this attribute will provide the firmware
277		given instance (ACPI _DSM instance number) of the PCI device.
278		The attribute will be created only if the firmware has given
279		an instance number to the PCI device. ACPI _DSM instance number
280		will be given priority if the system firmware provides SMBIOS
281		type 41 device type instance also.
282Users:
283		Userspace applications interested in knowing the
284		firmware assigned instance number of the PCI
285		device that can help in understanding the firmware
286		intended order of the PCI device.
287
288What:		/sys/bus/pci/devices/.../d3cold_allowed
289Date:		July 2012
290Contact:	Huang Ying <ying.huang@intel.com>
291Description:
292		d3cold_allowed is bit to control whether the corresponding PCI
293		device can be put into D3Cold state.  If it is cleared, the
294		device will never be put into D3Cold state.  If it is set, the
295		device may be put into D3Cold state if other requirements are
296		satisfied too.  Reading this attribute will show the current
297		value of d3cold_allowed bit.  Writing this attribute will set
298		the value of d3cold_allowed bit.
299
300What:		/sys/bus/pci/devices/.../sriov_totalvfs
301Date:		November 2012
302Contact:	Donald Dutile <ddutile@redhat.com>
303Description:
304		This file appears when a physical PCIe device supports SR-IOV.
305		Userspace applications can read this file to determine the
306		maximum number of Virtual Functions (VFs) a PCIe physical
307		function (PF) can support. Typically, this is the value reported
308		in the PF's SR-IOV extended capability structure's TotalVFs
309		element.  Drivers have the ability at probe time to reduce the
310		value read from this file via the pci_sriov_set_totalvfs()
311		function.
312
313What:		/sys/bus/pci/devices/.../sriov_numvfs
314Date:		November 2012
315Contact:	Donald Dutile <ddutile@redhat.com>
316Description:
317		This file appears when a physical PCIe device supports SR-IOV.
318		Userspace applications can read and write to this file to
319		determine and control the enablement or disablement of Virtual
320		Functions (VFs) on the physical function (PF). A read of this
321		file will return the number of VFs that are enabled on this PF.
322		A number written to this file will enable the specified
323		number of VFs. A userspace application would typically read the
324		file and check that the value is zero, and then write the number
325		of VFs that should be enabled on the PF; the value written
326		should be less than or equal to the value in the sriov_totalvfs
327		file. A userspace application wanting to disable the VFs would
328		write a zero to this file. The core ensures that valid values
329		are written to this file, and returns errors when values are not
330		valid.  For example, writing a 2 to this file when sriov_numvfs
331		is not 0 and not 2 already will return an error. Writing a 10
332		when the value of sriov_totalvfs is 8 will return an error.
333
334What:		/sys/bus/pci/devices/.../driver_override
335Date:		April 2014
336Contact:	Alex Williamson <alex.williamson@redhat.com>
337Description:
338		This file allows the driver for a device to be specified which
339		will override standard static and dynamic ID matching.  When
340		specified, only a driver with a name matching the value written
341		to driver_override will have an opportunity to bind to the
342		device.  The override is specified by writing a string to the
343		driver_override file (echo pci-stub > driver_override) and
344		may be cleared with an empty string (echo > driver_override).
345		This returns the device to standard matching rules binding.
346		Writing to driver_override does not automatically unbind the
347		device from its current driver or make any attempt to
348		automatically load the specified driver.  If no driver with a
349		matching name is currently loaded in the kernel, the device
350		will not bind to any driver.  This also allows devices to
351		opt-out of driver binding using a driver_override name such as
352		"none".  Only a single driver may be specified in the override,
353		there is no support for parsing delimiters.
354
355What:		/sys/bus/pci/devices/.../numa_node
356Date:		Oct 2014
357Contact:	Prarit Bhargava <prarit@redhat.com>
358Description:
359		This file contains the NUMA node to which the PCI device is
360		attached, or -1 if the node is unknown.  The initial value
361		comes from an ACPI _PXM method or a similar firmware
362		source.  If that is missing or incorrect, this file can be
363		written to override the node.  In that case, please report
364		a firmware bug to the system vendor.  Writing to this file
365		taints the kernel with TAINT_FIRMWARE_WORKAROUND, which
366		reduces the supportability of your system.
367
368What:		/sys/bus/pci/devices/.../revision
369Date:		November 2016
370Contact:	Emil Velikov <emil.l.velikov@gmail.com>
371Description:
372		This file contains the revision field of the PCI device.
373		The value comes from device config space. The file is read only.
374
375What:		/sys/bus/pci/devices/.../sriov_drivers_autoprobe
376Date:		April 2017
377Contact:	Bodong Wang<bodong@mellanox.com>
378Description:
379		This file is associated with the PF of a device that
380		supports SR-IOV.  It determines whether newly-enabled VFs
381		are immediately bound to a driver.  It initially contains
382		1, which means the kernel automatically binds VFs to a
383		compatible driver immediately after they are enabled.  If
384		an application writes 0 to the file before enabling VFs,
385		the kernel will not bind VFs to a driver.
386
387		A typical use case is to write 0 to this file, then enable
388		VFs, then assign the newly-created VFs to virtual machines.
389		Note that changing this file does not affect already-
390		enabled VFs.  In this scenario, the user must first disable
391		the VFs, write 0 to sriov_drivers_autoprobe, then re-enable
392		the VFs.
393
394		This is similar to /sys/bus/pci/drivers_autoprobe, but
395		affects only the VFs associated with a specific PF.
396
397What:		/sys/bus/pci/devices/.../p2pmem/size
398Date:		November 2017
399Contact:	Logan Gunthorpe <logang@deltatee.com>
400Description:
401		If the device has any Peer-to-Peer memory registered, this
402	        file contains the total amount of memory that the device
403		provides (in decimal).
404
405What:		/sys/bus/pci/devices/.../p2pmem/available
406Date:		November 2017
407Contact:	Logan Gunthorpe <logang@deltatee.com>
408Description:
409		If the device has any Peer-to-Peer memory registered, this
410	        file contains the amount of memory that has not been
411		allocated (in decimal).
412
413What:		/sys/bus/pci/devices/.../p2pmem/published
414Date:		November 2017
415Contact:	Logan Gunthorpe <logang@deltatee.com>
416Description:
417		If the device has any Peer-to-Peer memory registered, this
418	        file contains a '1' if the memory has been published for
419		use outside the driver that owns the device.
420
421What:		/sys/bus/pci/devices/.../p2pmem/allocate
422Date:		August 2022
423Contact:	Logan Gunthorpe <logang@deltatee.com>
424Description:
425		This file allows mapping p2pmem into userspace. For each
426		mmap() call on this file, the kernel will allocate a chunk
427		of Peer-to-Peer memory for use in Peer-to-Peer transactions.
428		This memory can be used in O_DIRECT calls to NVMe backed
429		files for Peer-to-Peer copies.
430
431What:		/sys/bus/pci/devices/.../link/clkpm
432		/sys/bus/pci/devices/.../link/l0s_aspm
433		/sys/bus/pci/devices/.../link/l1_aspm
434		/sys/bus/pci/devices/.../link/l1_1_aspm
435		/sys/bus/pci/devices/.../link/l1_2_aspm
436		/sys/bus/pci/devices/.../link/l1_1_pcipm
437		/sys/bus/pci/devices/.../link/l1_2_pcipm
438Date:		October 2019
439Contact:	Heiner Kallweit <hkallweit1@gmail.com>
440Description:	If ASPM is supported for an endpoint, these files can be
441		used to disable or enable the individual power management
442		states. Write y/1/on to enable, n/0/off to disable.
443
444What:		/sys/bus/pci/devices/.../power_state
445Date:		November 2020
446Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
447Description:
448		This file contains the current PCI power state of the device.
449		The value comes from the PCI kernel device state and can be one
450		of: "unknown", "error", "D0", D1", "D2", "D3hot", "D3cold".
451		The file is read only.
452
453What:		/sys/bus/pci/devices/.../sriov_vf_total_msix
454Date:		January 2021
455Contact:	Leon Romanovsky <leonro@nvidia.com>
456Description:
457		This file is associated with a SR-IOV physical function (PF).
458		It contains the total number of MSI-X vectors available for
459		assignment to all virtual functions (VFs) associated with PF.
460		The value will be zero if the device doesn't support this
461		functionality. For supported devices, the value will be
462		constant and won't be changed after MSI-X vectors assignment.
463
464What:		/sys/bus/pci/devices/.../sriov_vf_msix_count
465Date:		January 2021
466Contact:	Leon Romanovsky <leonro@nvidia.com>
467Description:
468		This file is associated with a SR-IOV virtual function (VF).
469		It allows configuration of the number of MSI-X vectors for
470		the VF. This allows devices that have a global pool of MSI-X
471		vectors to optimally divide them between VFs based on VF usage.
472
473		The values accepted are:
474		 * > 0 - this number will be reported as the Table Size in the
475			 VF's MSI-X capability
476		 * < 0 - not valid
477		 * = 0 - will reset to the device default value
478
479		The file is writable if the PF is bound to a driver that
480		implements ->sriov_set_msix_vec_count().
481
482What:		/sys/bus/pci/devices/.../resourceN_resize
483Date:		September 2022
484Contact:	Alex Williamson <alex.williamson@redhat.com>
485Description:
486		These files provide an interface to PCIe Resizable BAR support.
487		A file is created for each BAR resource (N) supported by the
488		PCIe Resizable BAR extended capability of the device.  Reading
489		each file exposes the bitmap of available resource sizes:
490
491		# cat resource1_resize
492		00000000000001c0
493
494		The bitmap represents supported resource sizes for the BAR,
495		where bit0 = 1MB, bit1 = 2MB, bit2 = 4MB, etc.  In the above
496		example the device supports 64MB, 128MB, and 256MB BAR sizes.
497
498		When writing the file, the user provides the bit position of
499		the desired resource size, for example:
500
501		# echo 7 > resource1_resize
502
503		This indicates to set the size value corresponding to bit 7,
504		128MB.  The resulting size is 2 ^ (bit# + 20).  This definition
505		matches the PCIe specification of this capability.
506
507		In order to make use of resource resizing, all PCI drivers must
508		be unbound from the device and peer devices under the same
509		parent bridge may need to be soft removed.  In the case of
510		VGA devices, writing a resize value will remove low level
511		console drivers from the device.  Raw users of pci-sysfs
512		resourceN attributes must be terminated prior to resizing.
513		Success of the resizing operation is not guaranteed.
514
515What:		/sys/bus/pci/devices/.../leds/*:enclosure:*/brightness
516What:		/sys/class/leds/*:enclosure:*/brightness
517Date:		August 2024
518KernelVersion:	6.12
519Description:
520		LED indications on PCIe storage enclosures which are controlled
521		through the NPEM interface (Native PCIe Enclosure Management,
522		PCIe r6.1 sec 6.28) are accessible as led class devices, both
523		below /sys/class/leds and below NPEM-capable PCI devices.
524
525		Although these led class devices could be manipulated manually,
526		in practice they are typically manipulated automatically by an
527		application such as ledmon(8).
528
529		The name of a led class device is as follows:
530		<bdf>:enclosure:<indication>
531		where:
532
533		- <bdf> is the domain, bus, device and function number
534		  (e.g. 10000:02:05.0)
535		- <indication> is a short description of the LED indication
536
537		Valid indications per PCIe r6.1 table 6-27 are:
538
539		- ok (drive is functioning normally)
540		- locate (drive is being identified by an admin)
541		- fail (drive is not functioning properly)
542		- rebuild (drive is part of an array that is rebuilding)
543		- pfa (drive is predicted to fail soon)
544		- hotspare (drive is marked to be used as a replacement)
545		- ica (drive is part of an array that is degraded)
546		- ifa (drive is part of an array that is failed)
547		- idt (drive is not the right type for the connector)
548		- disabled (drive is disabled, removal is safe)
549		- specific0 to specific7 (enclosure-specific indications)
550
551		Broadly, the indications fall into one of these categories:
552
553		- to signify drive state (ok, locate, fail, idt, disabled)
554		- to signify drive role or state in a software RAID array
555		  (rebuild, pfa, hotspare, ica, ifa)
556		- to signify any other role or state (specific0 to specific7)
557
558		Mandatory indications per PCIe r6.1 sec 7.9.19.2 comprise:
559		ok, locate, fail, rebuild. All others are optional.
560		A led class device is only visible if the corresponding
561		indication is supported by the device.
562
563		To manipulate the indications, write 0 (LED_OFF) or 1 (LED_ON)
564		to the "brightness" file. Note that manipulating an indication
565		may implicitly manipulate other indications at the vendor's
566		discretion. E.g. when the user lights up the "ok" indication,
567		the vendor may choose to automatically turn off the "fail"
568		indication. The current state of an indication can be
569		retrieved by reading its "brightness" file.
570
571		The PCIe Base Specification allows vendors leeway to choose
572		different colors or blinking patterns for the indications,
573		but they typically follow the IBPI standard. E.g. the "locate"
574		indication is usually presented as one or two LEDs blinking at
575		4 Hz frequency:
576		https://en.wikipedia.org/wiki/International_Blinking_Pattern_Interpretation
577
578		PCI Firmware Specification r3.3 sec 4.7 defines a DSM interface
579		to facilitate shared access by operating system and platform
580		firmware to a device's NPEM registers. The kernel will use
581		this DSM interface where available, instead of accessing NPEM
582		registers directly. The DSM interface does not support the
583		enclosure-specific indications "specific0" to "specific7",
584		hence the corresponding led class devices are unavailable if
585		the DSM interface is used.
586