Recent updates in pHyp Firmware and VIOS releases provide new infrastructure towards enabling Subordinate Command Response Queues (Sub-CRQs) such that each Sub-CRQ is a channel backed by an actual hardware queue in the FC stack on the partner VIOS. Sub-CRQs are registered with the firmware via hypercalls and then negotiated with the VIOS via new Management Datagrams (MADs) for channel setup. This initial implementation adds the necessary Sub-CRQ framework and implements the new MADs for negotiating and assigning a set of Sub-CRQs to associated VIOS HW backed channels. The event pool and locking still leverages the legacy single queue implementation, and as such lock contention is problematic when increasing the number of queues. However, this initial work demonstrates a 1.2x factor increase in IOPs when configured with two HW queues despite lock contention. changes in v2: * Patch 4: changed firmware support logging to dev_warn_once * Patch 6: adjusted locking * Patch 15: dropped logging verbosity, moved cancel event tracking into subqueue * Patch 17: removed write permission for migration module parameters drive hard reset after update to num of scsi channels changes in v2: * Patch 4: NULL'd scsi_scrq reference after deallocation * Patch 6: Added switch case to handle XPORT event * Patch 9: fixed ibmvfc_event leak and double free * added support for cancel command with MQ * added parameter toggles for MQ settings Tyrel Datwyler (18): ibmvfc: add vhost fields and defaults for MQ enablement ibmvfc: define hcall wrapper for registering a Sub-CRQ ibmvfc: add Subordinate CRQ definitions ibmvfc: add alloc/dealloc routines for SCSI Sub-CRQ Channels ibmvfc: add Sub-CRQ IRQ enable/disable routine ibmvfc: add handlers to drain and complete Sub-CRQ responses ibmvfc: define Sub-CRQ interrupt handler routine ibmvfc: map/request irq and register Sub-CRQ interrupt handler ibmvfc: implement channel enquiry and setup commands ibmvfc: advertise client support for using hardware channels ibmvfc: set and track hw queue in ibmvfc_event struct ibmvfc: send commands down HW Sub-CRQ when channelized ibmvfc: register Sub-CRQ handles with VIOS during channel setup ibmvfc: add cancel mad initialization helper ibmvfc: send Cancel MAD down each hw scsi channel ibmvfc: enable MQ and set reasonable defaults ibmvfc: provide modules parameters for MQ settings ibmvfc: drop host lock when completing commands in CRQ drivers/scsi/ibmvscsi/ibmvfc.c | 721 +++++++++++++++++++++++++++++---- drivers/scsi/ibmvscsi/ibmvfc.h | 79 +++- 2 files changed, 711 insertions(+), 89 deletions(-) -- 2.27.0
