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+.. 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.
+
+Regions may optionally allow directly reading from their contents without a
+snapshot. Direct read requests are not atomic. In particular a read request
+of size 256 bytes or larger will be split into multiple chunks. If atomic
+access is required, use a snapshot. A driver wishing to enable this for a
+region should implement the ``.read`` callback in the ``devlink_region_ops``
+structure. User space can request a direct read by using the
+``DEVLINK_ATTR_REGION_DIRECT`` attribute instead of specifying a snapshot
+id.
+
+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
+
+    # Read from the region without a snapshot
+    $ devlink region read pci/0000:00:05.0/fw-health address 16 length 16
+    0000000000000010 0000 0000 ffff ff04 0029 8c00 0028 8cc8
+
+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.