scsi: lpfc: Fix MRQ > 1 context list handling

Various oops including cpu LOCKUPs were seen.

For asynchronously received ius where the driver must assign exchange
resources, the resources were on a single get (free) list and put list
(finished, waiting to be put on get list). As all cpus are sharing the
lists, an interrupt for a receive frame may have to wait for all the
other cpus to place their done work onto the put list before it can
acquire the lock to pull from the list.

Fix by breaking the resource lists into per-cpu lists or at least more
than 1 list with cpu's sharing the lists). A cpu would allocate from the
free list for its own cpu, and put its done work on the its own put list
- avoiding the contention. As cpu load may vary, when empty, a cpu may
grab from another cpu, thereby changing resource distribution.  But
searching for a resource only occurs on 1 or a few cpus until a single
resource can be allocated. if the condition reoccurs, it starts looking
at a different cpu.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/drivers/scsi/lpfc/lpfc_crtn.h b/drivers/scsi/lpfc/lpfc_crtn.h
index da669dce12fe..7e300734b345 100644
--- a/drivers/scsi/lpfc/lpfc_crtn.h
+++ b/drivers/scsi/lpfc/lpfc_crtn.h
@@ -556,9 +556,8 @@ int lpfc_nvmet_update_targetport(struct lpfc_hba *phba);
 void lpfc_nvmet_destroy_targetport(struct lpfc_hba *phba);
 void lpfc_nvmet_unsol_ls_event(struct lpfc_hba *phba,
 			struct lpfc_sli_ring *pring, struct lpfc_iocbq *piocb);
-void lpfc_nvmet_unsol_fcp_event(struct lpfc_hba *phba,
-			struct lpfc_sli_ring *pring,
-			struct rqb_dmabuf *nvmebuf, uint64_t isr_ts);
+void lpfc_nvmet_unsol_fcp_event(struct lpfc_hba *phba, uint32_t idx,
+				struct rqb_dmabuf *nvmebuf, uint64_t isr_ts);
 void lpfc_nvme_mod_param_dep(struct lpfc_hba *phba);
 void lpfc_nvme_abort_fcreq_cmpl(struct lpfc_hba *phba,
 				struct lpfc_iocbq *cmdiocb,