[Skiboot] [PATCH v4] IPMI: Trigger OPAL TI in abort path.

[Vasant Hegde]

On 11/5/19 4:15 PM, Mahesh Salgaonkar wrote:
> The current assert/abort implementation for BMC based system invokes cec
> reboot after printing backtrace. This means that BMC never gets notified
> about OPAL crash/termination. This sometimes leads into never ending
> IPL-ing loop if OPAL keeps aborting very early in boot path.
> 
> Trigger a software xstop (OPAL TI) to inform BMC about the OPAL
> termination. BMC is capable of catching checkstop signal and facilitate in
> rebooting (IPL-ing) host.
> 
> With AutoReboot policy, OpenBMC handles checkstop signals and counts them
> against the reboot counter. In cases where OPAL is crashing before host
> reaches to runtime, OpenBMC will move the system in Quiesced state after 3
> or so attempts of IPL/reboot so that system can be debugged. When OPAL
> triggers software checkstop it causes all the CPU threads to be stooped and
> moved to quiesced state. Hence OPAL don't need to explicitly stop all CPUs
> before calling software xstop.
> 
> Signed-off-by: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>


Reviewed-by: Vasant Hegde <hegdevasant at linux.vnet.ibm.com>

-Vasant