From: James Smart james.smart@broadcom.com
[ Upstream commit 6b3b3bdb83b4ad51252d21bb13596db879e51850 ]
On loosely ordered memory systems (PPC for example), the WQE elements were being updated in memory, but not necessarily flushed before the separate doorbell was written to hw which would cause hw to dma the WQE element. Thus, the hardware occasionally received partially updated WQE data.
Add the memory barrier after updating the WQE memory.
Signed-off-by: Dick Kennedy dick.kennedy@broadcom.com Signed-off-by: James Smart james.smart@broadcom.com Reviewed-by: Hannes Reinecke hare@suse.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin alexander.levin@verizon.com --- drivers/scsi/lpfc/lpfc_sli.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 2d4f4b58dcfa..beec755a56c6 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -119,6 +119,8 @@ lpfc_sli4_wq_put(struct lpfc_queue *q, union lpfc_wqe *wqe) if (q->phba->sli3_options & LPFC_SLI4_PHWQ_ENABLED) bf_set(wqe_wqid, &wqe->generic.wqe_com, q->queue_id); lpfc_sli_pcimem_bcopy(wqe, temp_wqe, q->entry_size); + /* ensure WQE bcopy flushed before doorbell write */ + wmb();
/* Update the host index before invoking device */ host_index = q->host_index;