From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9AA6EC43387 for ; Fri, 4 Jan 2019 16:04:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63D76218CD for ; Fri, 4 Jan 2019 16:04:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726642AbfADQEf (ORCPT ); Fri, 4 Jan 2019 11:04:35 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:17115 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726053AbfADQEe (ORCPT ); Fri, 4 Jan 2019 11:04:34 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id A022DDF777DD; Sat, 5 Jan 2019 00:04:30 +0800 (CST) Received: from [127.0.0.1] (10.202.226.43) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.408.0; Sat, 5 Jan 2019 00:04:30 +0800 Subject: Re: [PATCH] scsi/mvsas/mv_init.c: Use dma_zalloc_coherent To: Sabyasachi Gupta References: <5bf56248.1c69fb81.21a6e.5a72@mx.google.com> CC: , , , Souptick Joarder , , , Brajeswar Ghosh From: John Garry Message-ID: <8af8ef0a-add1-1010-6ef3-7e5c6ff51aa9@huawei.com> Date: Fri, 4 Jan 2019 16:04:24 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.43] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/01/2019 15:11, Sabyasachi Gupta wrote: > On Fri, Jan 4, 2019 at 6:43 PM John Garry wrote: >> >> On 04/01/2019 12:48, Sabyasachi Gupta wrote: >>> On Wed, Dec 19, 2018 at 6:49 PM Sabyasachi Gupta >>> wrote: >>>> >>>> On Sat, Dec 1, 2018 at 6:40 PM Sabyasachi Gupta >>>> wrote: >>>>> >>>>> On Wed, Nov 21, 2018 at 7:18 PM Sabyasachi Gupta >>>>> wrote: >>>>>> >>>>>> Replace dma_alloc_coherent + memset with dma_zalloc_coherent >>>>>> >> >> If you're going to make this change, then how about change these to the >> managed version, so that we can avoid the explicit free'ing at driver >> removal? > > I can't get it Please see dmam_alloc_coherent(). You can set __GFP_ZERO in the gfp argument to memset(0). I would say that this is a more useful change. > >> >>>>>> Signed-off-by: Sabyasachi Gupta >>>>> >>>>> Any comment on this patch? >>>> >>>> Any comment on this patch? >>> >>> Any comment on this patch? >>> >>>> >>>>> >>>>>> --- >>>>>> drivers/scsi/mvsas/mv_init.c | 12 ++++-------- >>>>>> 1 file changed, 4 insertions(+), 8 deletions(-) >>>>>> >>>>>> diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c >>>>>> index 3ac3437..495bddb 100644 >>>>>> --- a/drivers/scsi/mvsas/mv_init.c >>>>>> +++ b/drivers/scsi/mvsas/mv_init.c >>>>>> @@ -253,33 +253,29 @@ static int mvs_alloc(struct mvs_info *mvi, struct Scsi_Host *shost) >>>>>> /* >>>>>> * alloc and init our DMA areas >>>>>> */ >>>>>> - mvi->tx = dma_alloc_coherent(mvi->dev, >>>>>> + mvi->tx = dma_zalloc_coherent(mvi->dev, >>>>>> sizeof(*mvi->tx) * MVS_CHIP_SLOT_SZ, >>>>>> &mvi->tx_dma, GFP_KERNEL); >> >> I'm guessing that this does not pass checkpatch with --strict option. >> >> Thanks, >> John > > I have not not checked with --strict option It may warn that you're not maintaining alignment. > >> >>>>>> if (!mvi->tx) >>>>>> goto err_out; >>>>>> - memset(mvi->tx, 0, sizeof(*mvi->tx) * MVS_CHIP_SLOT_SZ); >>>>>> - mvi->rx_fis = dma_alloc_coherent(mvi->dev, MVS_RX_FISL_SZ, >>>>>> + mvi->rx_fis = dma_zalloc_coherent(mvi->dev, MVS_RX_FISL_SZ, >>>>>> &mvi->rx_fis_dma, GFP_KERNEL); >>>>>> if (!mvi->rx_fis) >>>>>> goto err_out; >>>>>> - memset(mvi->rx_fis, 0, MVS_RX_FISL_SZ); >>>>>> >>>>>> - mvi->rx = dma_alloc_coherent(mvi->dev, >>>>>> + mvi->rx = dma_zalloc_coherent(mvi->dev, >>>>>> sizeof(*mvi->rx) * (MVS_RX_RING_SZ + 1), >>>>>> &mvi->rx_dma, GFP_KERNEL); >>>>>> if (!mvi->rx) >>>>>> goto err_out; >>>>>> - memset(mvi->rx, 0, sizeof(*mvi->rx) * (MVS_RX_RING_SZ + 1)); >>>>>> mvi->rx[0] = cpu_to_le32(0xfff); >>>>>> mvi->rx_cons = 0xfff; >>>>>> >>>>>> - mvi->slot = dma_alloc_coherent(mvi->dev, >>>>>> + mvi->slot = dma_zalloc_coherent(mvi->dev, >>>>>> sizeof(*mvi->slot) * slot_nr, >>>>>> &mvi->slot_dma, GFP_KERNEL); >>>>>> if (!mvi->slot) >>>>>> goto err_out; >>>>>> - memset(mvi->slot, 0, sizeof(*mvi->slot) * slot_nr); >>>>>> >>>>>> mvi->bulk_buffer = dma_alloc_coherent(mvi->dev, >>>>>> TRASH_BUCKET_SIZE, >>>>>> -- >>>>>> 2.7.4 >>>>>> >>> >>> . >>> >> >> > > . >