[Skiboot] [PATCH 014/110] doc: prettify OPAL_QUIESCE
Stewart Smith
stewart at linux.ibm.com
Fri May 31 16:12:15 AEST 2019
Signed-off-by: Stewart Smith <stewart at linux.ibm.com>
---
doc/opal-api/opal-quiesce-158.rst | 87 ++++++++++++++++++-------------
1 file changed, 50 insertions(+), 37 deletions(-)
diff --git a/doc/opal-api/opal-quiesce-158.rst b/doc/opal-api/opal-quiesce-158.rst
index 19604396b541..babbe04131e4 100644
--- a/doc/opal-api/opal-quiesce-158.rst
+++ b/doc/opal-api/opal-quiesce-158.rst
@@ -1,58 +1,71 @@
-.. _opal-quiesce:
+.. _OPAL_QUIESCE:
OPAL_QUIESCE
============
-The host OS can use OPAL_QUIESCE to ensure CPUs under host control are not
+.. code-block:: c
+
+ #define OPAL_QUIESCE 158
+
+ int64_t opal_quiesce(uint32_t quiesce_type, int32_t cpu_target);
+
+The host OS can use :ref:`OPAL_QUIESCE` to ensure CPUs under host control are not
executing OPAL. This is useful in crash or shutdown scenarios to try to
ensure that CPUs are not holding locks, and is intended to be used with
-OPAL_SIGNAL_SYSTEM_RESET, for example.
+:ref:`OPAL_SIGNAL_SYSTEM_RESET`, for example.
Arguments
---------
-::
-
- uint32_t quiesce_type
- QUIESCE_HOLD Wait for all target(s) currently executing OPAL to
- return to the host. Any new OPAL call that is made
- will be held off until QUIESCE_RESUME.
- QUIESCE_REJECT Wait for all target(s) currently executing OPAL to
- return to the host. Any new OPAL call that is made
- will fail with OPAL_BUSY until QUIESCE_RESUME.
- QUIESCE_LOCK_BREAK After QUIESCE_HOLD or QUIESCE_REJECT is successful,
- the CPU can call QUIESCE_LOCK_BREAK to skip all
- locking in OPAL to give the best chance of making
- progress in the crash/debug paths. The host should
- ensure all other CPUs are stopped (e.g., with
- OPAL_SIGNAL_SYSTEM_RESET) before this call is made, to
- avoid concurrency.
- QUIESCE_RESUME Undo the effects of QUIESCE_HOLD/QUIESCE_REJECT and
- QUIESCE_LOCK_BREAK calls.
- QUIESCE_RESUME_FAST_REBOOT
- As above, but also reset the tracking of OS calls
- into firmware as part of fast reboot (secondaries
- will never return to OS, but instead be released
- into a new OS boot).
-
- int32_t target_cpu
- cpu_nr >= 0 The cpu server number of the target cpu to reset.
- -1 All cpus except the current one should be quiesced.
+
+quiesce_type
+^^^^^^^^^^^^
+
+QUIESCE_HOLD
+ Wait for all target(s) currently executing OPAL to
+ return to the host. Any new OPAL call that is made
+ will be held off until QUIESCE_RESUME.
+QUIESCE_REJECT
+ Wait for all target(s) currently executing OPAL to
+ return to the host. Any new OPAL call that is made
+ will fail with OPAL_BUSY until QUIESCE_RESUME.
+QUIESCE_LOCK_BREAK
+ After QUIESCE_HOLD or QUIESCE_REJECT is successful,
+ the CPU can call QUIESCE_LOCK_BREAK to skip all
+ locking in OPAL to give the best chance of making
+ progress in the crash/debug paths. The host should
+ ensure all other CPUs are stopped (e.g., with
+ OPAL_SIGNAL_SYSTEM_RESET) before this call is made, to
+ avoid concurrency.
+QUIESCE_RESUME
+ Undo the effects of QUIESCE_HOLD/QUIESCE_REJECT and
+ QUIESCE_LOCK_BREAK calls.
+QUIESCE_RESUME_FAST_REBOOT
+ As above, but also reset the tracking of OS calls
+ into firmware as part of fast reboot (secondaries
+ will never return to OS, but instead be released
+ into a new OS boot).
+
+target_cpu
+^^^^^^^^^^
+
+``cpu_nr >= 0``
+ The cpu server number of the target cpu to reset.
+``-1``
+ All cpus except the current one should be quiesced.
Returns
-------
-OPAL_SUCCESS
- The quiesce call was successful.
-OPAL_PARTIAL
+:ref:`OPAL_SUCCESS`
+ The quiesce call was successful.
+:ref:`OPAL_PARTIAL`
Some or all of the CPUs executing OPAL when the call was made did not
return to the host after a timeout of 1 second. This is a best effort
at quiescing OPAL, and QUIESCE_RESUME must be called to resume normal
firmware operation.
-
-OPAL_PARAMETER
+:ref:`OPAL_PARAMETER`
A parameter was incorrect.
-
-OPAL_BUSY
+:ref:`OPAL_BUSY`
This CPU was not able to complete the operation, either because another
has concurrently started quiescing the system, or because it has not
successfully called QUIESCE_HOLD or QUIESCE_REJECT before attempting
--
2.21.0
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