OPAL_QUIESCE

#define OPAL_QUIESCE                         158

int64_t opal_quiesce(uint32_t quiesce_type, int32_t cpu_target);

The host OS can use 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.

Arguments

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
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
A parameter was incorrect.
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 QUIESCE_LOCK_BREAK or QUIESCE_RESUME.