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* SBE: Add timer supportVasant Hegde2018-04-301-2/+183
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SBE on P9 provides one shot programmable timer facility. We can use this to implement OPAL timers and hence limit the reliance on the Linux heartbeat (similar to HW timer facility provided by SLW on P8). Design: - We will continue to run Linux heartbeat. - Each chip has SBE. This patch always schedules timer on SBE on master chip. - Start timer option starts new timer or modifies an active timer for the specified timeout. - SBE expects timeout value in microseconds. We track timeout value in TB. Hence we convert tb to microseconds before sending request to SBE. - We are requesting ack from SBE for timer message. It gaurantees that SBE has scheduled timer. - Disabling SBE timer We expect SBE to send timer expiry interrupt whenever timer expires. We wait for 10 more ms before disabling timer. In future we can consider below alternative approaches: - Presently SBE timer disable is permanent (until we reboot system). SBE sends "I'm back" interrupt after reset. We can consider restarting timer after SBE reset. - Reset SBE and start timer again. - Each chip has SBE. On multi chip system we can try to schedule timer on different chip. Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> CC: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
* Add SBE driver supportVasant Hegde2018-04-301-18/+678
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SBE (Self Boot Engine) on P9 has two different jobs: - Boot the chip up to the point the core is functional - Provide various services like timer, scom, stash MPIPL, etc., at runtime OPAL can communicate to SBE via a set of data and control registers provided by the PSU block in P9 chip. - Four 8 byte registers for Host to send command packets to SBE - Four 8 byte registers for SBE to send response packets to Host - Two doorbell registers (1 on each side) to alert either party when data is placed in above mentioned data register Protocol constraints: Only one command is accepted in the command buffer until the response for the command is enqueued in the response buffer by SBE. Usage: We will use SBE for various purposes like timer, MPIPL, etc. This patch implements the SBE MBOX spec for OPAL to communicate with SBE. Design consideration: - Each chip has SBE. We need to track SBE messages per chip. Hence added per chip sbe structure and list of messages to that chip - SBE accepts only one command at a time. Hence serialized MBOX commands. - OPAL gets interrupted once SBE sets doorbell register - OPAL has to clear doorbell register after reading response - Every command class has timeout option. Timed out messages are discarded - SBE MBOX commands can be classified into four types : - Those that must be sent to the master only (ex: sending MDST/MDDT info) - Those that must be sent to slaves only (ex: continue MPIPL) - Those that must be sent to all chips (ex: close insecure window) - Those that can be sent to any chip (ex: timer) Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
* SBE: Add passthrough command supportVasant Hegde2017-06-081-0/+61
SBE sends passthrough command. We have to capture this interrupt and send event to HBRT via opal-prd (user space daemon). This patch adds minimal SBE code to capture SBE interrupt and send event to opal-prd. Next patch will add opal-prd (user space) support. CC: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
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