Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 119 insertions, 0 deletions

diff --git a/Documentation/networking/devlink/devlink-health.rst b/Documentation/networking/devlink/devlink-health.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+==============
+Devlink Health
+==============
+
+Background
+==========
+
+The ``devlink`` health mechanism is targeted for Real Time Alerting, in
+order to know when something bad happened to a PCI device.
+
+  * Provide alert debug information.
+  * Self healing.
+  * If problem needs vendor support, provide a way to gather all needed
+    debugging information.
+
+Overview
+========
+
+The main idea is to unify and centralize driver health reports in the
+generic ``devlink`` instance and allow the user to set different
+attributes of the health reporting and recovery procedures.
+
+The ``devlink`` health reporter:
+Device driver creates a "health reporter" per each error/health type.
+Error/Health type can be a known/generic (e.g. PCI error, fw error, rx/tx error)
+or unknown (driver specific).
+For each registered health reporter a driver can issue error/health reports
+asynchronously. All health reports handling is done by ``devlink``.
+Device driver can provide specific callbacks for each "health reporter", e.g.:
+
+  * Recovery procedures
+  * Diagnostics procedures
+  * Object dump procedures
+  * OOB initial parameters
+
+Different parts of the driver can register different types of health reporters
+with different handlers.
+
+Actions
+=======
+
+Once an error is reported, devlink health will perform the following actions:
+
+  * A log is being send to the kernel trace events buffer
+  * Health status and statistics are being updated for the reporter instance
+  * Object dump is being taken and saved at the reporter instance (as long as
+    there is no other dump which is already stored)
+  * Auto recovery attempt is being done. Depends on:
+
+    - Auto-recovery configuration
+    - Grace period vs. time passed since last recover
+
+User Interface
+==============
+
+User can access/change each reporter's parameters and driver specific callbacks
+via ``devlink``, e.g per error type (per health reporter):
+
+  * Configure reporter's generic parameters (like: disable/enable auto recovery)
+  * Invoke recovery procedure
+  * Run diagnostics
+  * Object dump
+
+.. list-table:: List of devlink health interfaces
+   :widths: 10 90
+
+   * - Name
+     - Description
+   * - ``DEVLINK_CMD_HEALTH_REPORTER_GET``
+     - Retrieves status and configuration info per DEV and reporter.
+   * - ``DEVLINK_CMD_HEALTH_REPORTER_SET``
+     - Allows reporter-related configuration setting.
+   * - ``DEVLINK_CMD_HEALTH_REPORTER_RECOVER``
+     - Triggers reporter's recovery procedure.
+   * - ``DEVLINK_CMD_HEALTH_REPORTER_TEST``
+     - Triggers a fake health event on the reporter. The effects of the test
+       event in terms of recovery flow should follow closely that of a real
+       event.
+   * - ``DEVLINK_CMD_HEALTH_REPORTER_DIAGNOSE``
+     - Retrieves current device state related to the reporter.
+   * - ``DEVLINK_CMD_HEALTH_REPORTER_DUMP_GET``
+     - Retrieves the last stored dump. Devlink health
+       saves a single dump. If an dump is not already stored by devlink
+       for this reporter, devlink generates a new dump.
+       Dump output is defined by the reporter.
+   * - ``DEVLINK_CMD_HEALTH_REPORTER_DUMP_CLEAR``
+     - Clears the last saved dump file for the specified reporter.
+
+The following diagram provides a general overview of ``devlink-health``::
+
+                                                   netlink
+                                          +--------------------------+
+                                          |                          |
+                                          |            +             |
+                                          |            |             |
+                                          +--------------------------+
+                                                       |request for ops
+                                                       |(diagnose,
+      driver                               devlink     |recover,
+                                                       |dump)
+    +--------+                            +--------------------------+
+    |        |                            |    reporter|             |
+    |        |                            |  +---------v----------+  |
+    |        |   ops execution            |  |                    |  |
+    |     <----------------------------------+                    |  |
+    |        |                            |  |                    |  |
+    |        |                            |  + ^------------------+  |
+    |        |                            |    | request for ops     |
+    |        |                            |    | (recover, dump)     |
+    |        |                            |    |                     |
+    |        |                            |  +-+------------------+  |
+    |        |     health report          |  | health handler     |  |
+    |        +------------------------------->                    |  |
+    |        |                            |  +--------------------+  |
+    |        |     health reporter create |                          |
+    |        +---------------------------->                          |
+    +--------+                            +--------------------------+