[Skiboot] [PATCH 10/12] opal: Enable backup topology.

Stewart Smith stewart at linux.vnet.ibm.com
Thu May 7 07:13:24 AEST 2015

Mahesh Jagannath Salgaonkar <mahesh at linux.vnet.ibm.com> writes:

> On 04/22/2015 09:49 AM, Stewart Smith wrote:
>> Mahesh J Salgaonkar <mahesh at linux.vnet.ibm.com> writes:
>>> Whenever FSP makes any changes to backup topology as part of either
>>> routine hardware maintenance or fixing failed backup topology configuration,
>>> it sends out mailbox command xE6, s/c 0x06, mod 0, to enable/disable
>>> the backup topology. OPAL layer should keep itself up-to-date with accurate
>>> details of current topology configurations. This will help OPAL layer to
>>> successfully handle any TOD failover in future.
>>> The FSP can only request that the currently inactive (backup) topology be
>>> disabled or enabled. If the requested topology is currently the active
>>> topology, then fail this request with a 0xB8 (TOD topology in use) status
>>> as return code.
>>> For disable request, set the backup topology status as disabled.
>>> For enable request, scan all the available chips and find the new backup
>>> master chip by looking at TOD status register of each chip.
>>> Signed-off-by: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>
>>> ---
>>>  hw/chiptod.c               |  106 ++++++++++++++++++++++++++++++++++++++++++++
>>>  include/fsp.h              |    9 ++++
>>>  platforms/ibm-fsp/common.c |    3 +
>> Should this be a platform call rather than having FSP code leak into
>> common hw code?
> I am not sure I understood your question.
> fsp_chiptod_init() registers a client to monitor/listen FSP mailbox
> commands of specific Mbox CLASS (E6 = HW maintanance) and need to be
> called during platform init.
> I see that platform init call points to ibm_fsp_init() defined in
> ibm-fsp/common.c. Hence I have just hooked fsp_chiptod_init() in
> ibm_fsp_init() function where bunch of other fsp_* functions are invoked.
> Do you think that's not the right way to do it ?

More concerned about the FSP specific code being introduced into
hw/chiptod.c - any reason that code should be there rather somewhere in
platforms/ibm-fsp ?

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