From patchwork Tue Jun 18 01:37:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 11000751 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8BCBA14E5 for ; Tue, 18 Jun 2019 01:38:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7C84328614 for ; Tue, 18 Jun 2019 01:38:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 70A922868D; Tue, 18 Jun 2019 01:38:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 23B40286CC for ; Tue, 18 Jun 2019 01:38:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727349AbfFRBiu (ORCPT ); Mon, 17 Jun 2019 21:38:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39058 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726642AbfFRBit (ORCPT ); Mon, 17 Jun 2019 21:38:49 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2693A3082208; Tue, 18 Jun 2019 01:38:49 +0000 (UTC) Received: from localhost (ovpn-8-17.pek2.redhat.com [10.72.8.17]) by smtp.corp.redhat.com (Postfix) with ESMTP id 42B2710027B7; Tue, 18 Jun 2019 01:38:45 +0000 (UTC) From: Ming Lei To: linux-scsi@vger.kernel.org, "Martin K . Petersen" Cc: James Bottomley , Bart Van Assche , Hannes Reinecke , Christoph Hellwig , Jim Gill , Cathy Avery , "Ewan D . Milne" , Brian King , James Smart , "Juergen E . Fischer" , Michael Schmitz , Finn Thain , Greg Kroah-Hartman , devel@driverdev.osuosl.org, linux-usb@vger.kernel.org, Dan Carpenter , Benjamin Block , Ming Lei Subject: [PATCH V5 06/16] scsi: pmcraid: use sg helper to operate scatterlist Date: Tue, 18 Jun 2019 09:37:47 +0800 Message-Id: <20190618013757.22401-7-ming.lei@redhat.com> In-Reply-To: <20190618013757.22401-1-ming.lei@redhat.com> References: <20190618013757.22401-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Tue, 18 Jun 2019 01:38:49 +0000 (UTC) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Use the scatterlist iterators and remove direct indexing of the scatterlist array. This way allows us to pre-allocate one small scatterlist, which can be chained with one runtime allocated scatterlist if the pre-allocated one isn't enough for the whole request. Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Signed-off-by: Ming Lei --- drivers/scsi/pmcraid.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c index e338d7a4f571..286cac59cb5f 100644 --- a/drivers/scsi/pmcraid.c +++ b/drivers/scsi/pmcraid.c @@ -3270,7 +3270,7 @@ static int pmcraid_copy_sglist( int direction ) { - struct scatterlist *scatterlist; + struct scatterlist *sg; void *kaddr; int bsize_elem; int i; @@ -3279,10 +3279,10 @@ static int pmcraid_copy_sglist( /* Determine the actual number of bytes per element */ bsize_elem = PAGE_SIZE * (1 << sglist->order); - scatterlist = sglist->scatterlist; + sg = sglist->scatterlist; - for (i = 0; i < (len / bsize_elem); i++, buffer += bsize_elem) { - struct page *page = sg_page(&scatterlist[i]); + for (i = 0; i < (len / bsize_elem); i++, sg = sg_next(sg), buffer += bsize_elem) { + struct page *page = sg_page(sg); kaddr = kmap(page); if (direction == DMA_TO_DEVICE) @@ -3297,11 +3297,11 @@ static int pmcraid_copy_sglist( return -EFAULT; } - scatterlist[i].length = bsize_elem; + sg->length = bsize_elem; } if (len % bsize_elem) { - struct page *page = sg_page(&scatterlist[i]); + struct page *page = sg_page(sg); kaddr = kmap(page); @@ -3312,7 +3312,7 @@ static int pmcraid_copy_sglist( kunmap(page); - scatterlist[i].length = len % bsize_elem; + sg->length = len % bsize_elem; } if (rc) {