From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753569AbdKHVIT (ORCPT ); Wed, 8 Nov 2017 16:08:19 -0500 Received: from omzsmtpe02.verizonbusiness.com ([199.249.25.209]:7127 "EHLO omzsmtpe02.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752503AbdKHVBU (ORCPT ); Wed, 8 Nov 2017 16:01:20 -0500 X-Host: endeavour.tdc.vzwcorp.com From: "Levin, Alexander (Sasha Levin)" To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" CC: James Smart , Dick Kennedy , "Martin K . Petersen" , "Levin, Alexander (Sasha Levin)" Subject: [PATCH AUTOSEL for-4.9 22/53] scsi: lpfc: Add missing memory barrier Thread-Topic: [PATCH AUTOSEL for-4.9 22/53] scsi: lpfc: Add missing memory barrier Thread-Index: AQHTWNMkq+Vf1FDrREaikFI33cAxqA== Date: Wed, 8 Nov 2017 20:50:00 +0000 Message-ID: <20171108204940.27321-22-alexander.levin@verizon.com> References: <20171108204940.27321-1-alexander.levin@verizon.com> In-Reply-To: <20171108204940.27321-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vA8L8Pb8003948 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 --- 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; -- 2.11.0