forked from Minki/linux
a70e3f024d
Each region has an independently configurable number of maximum snapshots. This information is not reported to userspace, making it not very discoverable. Fix this by adding a new DEVLINK_ATTR_REGION_MAX_SNAPSHOST attribute which is used to report this maximum. Ex: $devlink region pci/0000:af:00.0/nvm-flash: size 10485760 snapshot [] max 1 pci/0000:af:00.0/device-caps: size 4096 snapshot [] max 10 pci/0000:af:00.1/nvm-flash: size 10485760 snapshot [] max 1 pci/0000:af:00.1/device-caps: size 4096 snapshot [] max 10 This information enables users to understand why a new region command may fail due to having too many existing snapshots. Reported-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel) Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
71 lines
2.8 KiB
ReStructuredText
71 lines
2.8 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
|
|
|
|
==============
|
|
Devlink Region
|
|
==============
|
|
|
|
``devlink`` regions enable access to driver defined address regions using
|
|
devlink.
|
|
|
|
Each device can create and register its own supported address regions. The
|
|
region can then be accessed via the devlink region interface.
|
|
|
|
Region snapshots are collected by the driver, and can be accessed via read
|
|
or dump commands. This allows future analysis on the created snapshots.
|
|
Regions may optionally support triggering snapshots on demand.
|
|
|
|
Snapshot identifiers are scoped to the devlink instance, not a region.
|
|
All snapshots with the same snapshot id within a devlink instance
|
|
correspond to the same event.
|
|
|
|
The major benefit to creating a region is to provide access to internal
|
|
address regions that are otherwise inaccessible to the user.
|
|
|
|
Regions may also be used to provide an additional way to debug complex error
|
|
states, but see also Documentation/networking/devlink/devlink-health.rst
|
|
|
|
Regions may optionally support capturing a snapshot on demand via the
|
|
``DEVLINK_CMD_REGION_NEW`` netlink message. A driver wishing to allow
|
|
requested snapshots must implement the ``.snapshot`` callback for the region
|
|
in its ``devlink_region_ops`` structure. If snapshot id is not set in
|
|
the ``DEVLINK_CMD_REGION_NEW`` request kernel will allocate one and send
|
|
the snapshot information to user space.
|
|
|
|
example usage
|
|
-------------
|
|
|
|
.. code:: shell
|
|
|
|
$ devlink region help
|
|
$ devlink region show [ DEV/REGION ]
|
|
$ devlink region del DEV/REGION snapshot SNAPSHOT_ID
|
|
$ devlink region dump DEV/REGION [ snapshot SNAPSHOT_ID ]
|
|
$ devlink region read DEV/REGION [ snapshot SNAPSHOT_ID ] address ADDRESS length length
|
|
|
|
# Show all of the exposed regions with region sizes:
|
|
$ devlink region show
|
|
pci/0000:00:05.0/cr-space: size 1048576 snapshot [1 2] max 8
|
|
pci/0000:00:05.0/fw-health: size 64 snapshot [1 2] max 8
|
|
|
|
# Delete a snapshot using:
|
|
$ devlink region del pci/0000:00:05.0/cr-space snapshot 1
|
|
|
|
# Request an immediate snapshot, if supported by the region
|
|
$ devlink region new pci/0000:00:05.0/cr-space
|
|
pci/0000:00:05.0/cr-space: snapshot 5
|
|
|
|
# Dump a snapshot:
|
|
$ devlink region dump pci/0000:00:05.0/fw-health snapshot 1
|
|
0000000000000000 0014 95dc 0014 9514 0035 1670 0034 db30
|
|
0000000000000010 0000 0000 ffff ff04 0029 8c00 0028 8cc8
|
|
0000000000000020 0016 0bb8 0016 1720 0000 0000 c00f 3ffc
|
|
0000000000000030 bada cce5 bada cce5 bada cce5 bada cce5
|
|
|
|
# Read a specific part of a snapshot:
|
|
$ devlink region read pci/0000:00:05.0/fw-health snapshot 1 address 0 length 16
|
|
0000000000000000 0014 95dc 0014 9514 0035 1670 0034 db30
|
|
|
|
As regions are likely very device or driver specific, no generic regions are
|
|
defined. See the driver-specific documentation files for information on the
|
|
specific regions a driver supports.
|