From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:52280 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751593AbdKSOea (ORCPT ); Sun, 19 Nov 2017 09:34:30 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dick Kennedy , James Smart , Hannes Reinecke , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.4 29/59] scsi: lpfc: Add missing memory barrier Date: Sun, 19 Nov 2017 15:32:37 +0100 Message-Id: <20171119143152.294529501@linuxfoundation.org> In-Reply-To: <20171119143150.964013720@linuxfoundation.org> References: <20171119143150.964013720@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Smart [ 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 Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/lpfc/lpfc_sli.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -118,6 +118,8 @@ lpfc_sli4_wq_put(struct lpfc_queue *q, u 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;