From patchwork Fri Jun 14 02:53:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 10994117 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 0BA6176 for ; Fri, 14 Jun 2019 02:54:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F325426E3C for ; Fri, 14 Jun 2019 02:54:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E4FDE26E3E; Fri, 14 Jun 2019 02:54:48 +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=ham 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 7974D232A7 for ; Fri, 14 Jun 2019 02:54:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726831AbfFNCyr (ORCPT ); Thu, 13 Jun 2019 22:54:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34668 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726259AbfFNCyp (ORCPT ); Thu, 13 Jun 2019 22:54:45 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8BDF35944C; Fri, 14 Jun 2019 02:54:44 +0000 (UTC) Received: from localhost (ovpn-8-21.pek2.redhat.com [10.72.8.21]) by smtp.corp.redhat.com (Postfix) with ESMTP id C24375C3F8; Fri, 14 Jun 2019 02:54:43 +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 Subject: [PATCH V3 15/15] NCR5380: Support chained sg lists Date: Fri, 14 Jun 2019 10:53:16 +0800 Message-Id: <20190614025316.7360-16-ming.lei@redhat.com> In-Reply-To: <20190614025316.7360-1-ming.lei@redhat.com> References: <20190614025316.7360-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 14 Jun 2019 02:54:44 +0000 (UTC) Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Finn Thain My understanding is that support for chained scatterlists is to become mandatory for LLDs. 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. Cc: Michael Schmitz Reviewed-by: Michael Schmitz Signed-off-by: Finn Thain --- drivers/scsi/NCR5380.c | 41 ++++++++++++++++++----------------------- 1 file changed, 18 insertions(+), 23 deletions(-) diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c index fe0535affc14..4ef44fafe6ca 100644 --- a/drivers/scsi/NCR5380.c +++ b/drivers/scsi/NCR5380.c @@ -149,12 +149,10 @@ static inline void initialize_SCp(struct scsi_cmnd *cmd) if (scsi_bufflen(cmd)) { cmd->SCp.buffer = scsi_sglist(cmd); - cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1; cmd->SCp.ptr = sg_virt(cmd->SCp.buffer); cmd->SCp.this_residual = cmd->SCp.buffer->length; } else { cmd->SCp.buffer = NULL; - cmd->SCp.buffers_residual = 0; cmd->SCp.ptr = NULL; cmd->SCp.this_residual = 0; } @@ -163,6 +161,17 @@ static inline void initialize_SCp(struct scsi_cmnd *cmd) cmd->SCp.Message = 0; } +static inline void advance_sg_buffer(struct scsi_cmnd *cmd) +{ + struct scatterlist *s = cmd->SCp.buffer; + + if (!cmd->SCp.this_residual && s && !sg_is_last(s)) { + cmd->SCp.buffer = sg_next(s); + cmd->SCp.ptr = sg_virt(cmd->SCp.buffer); + cmd->SCp.this_residual = cmd->SCp.buffer->length; + } +} + /** * NCR5380_poll_politely2 - wait for two chip register values * @hostdata: host private data @@ -1672,12 +1681,7 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) sun3_dma_setup_done != cmd) { int count; - if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) { - ++cmd->SCp.buffer; - --cmd->SCp.buffers_residual; - cmd->SCp.this_residual = cmd->SCp.buffer->length; - cmd->SCp.ptr = sg_virt(cmd->SCp.buffer); - } + advance_sg_buffer(cmd); count = sun3scsi_dma_xfer_len(hostdata, cmd); @@ -1727,15 +1731,11 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) * scatter-gather list, move onto the next one. */ - if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) { - ++cmd->SCp.buffer; - --cmd->SCp.buffers_residual; - cmd->SCp.this_residual = cmd->SCp.buffer->length; - cmd->SCp.ptr = sg_virt(cmd->SCp.buffer); - dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n", - cmd->SCp.this_residual, - cmd->SCp.buffers_residual); - } + advance_sg_buffer(cmd); + dsprintk(NDEBUG_INFORMATION, instance, + "this residual %d, sg ents %d\n", + cmd->SCp.this_residual, + sg_nents(cmd->SCp.buffer)); /* * The preferred transfer method is going to be @@ -2136,12 +2136,7 @@ static void NCR5380_reselect(struct Scsi_Host *instance) if (sun3_dma_setup_done != tmp) { int count; - if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) { - ++tmp->SCp.buffer; - --tmp->SCp.buffers_residual; - tmp->SCp.this_residual = tmp->SCp.buffer->length; - tmp->SCp.ptr = sg_virt(tmp->SCp.buffer); - } + advance_sg_buffer(tmp); count = sun3scsi_dma_xfer_len(hostdata, tmp);