From patchwork Sat Oct 3 17:16:07 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 7322071 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 578129F1B9 for ; Sat, 3 Oct 2015 17:20:10 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 74717207A1 for ; Sat, 3 Oct 2015 17:20:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C854120794 for ; Sat, 3 Oct 2015 17:20:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750947AbbJCRUH (ORCPT ); Sat, 3 Oct 2015 13:20:07 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:43662 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750745AbbJCRUG (ORCPT ); Sat, 3 Oct 2015 13:20:06 -0400 Received: from [83.175.99.196] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZiQTQ-00081x-LQ; Sat, 03 Oct 2015 17:19:53 +0000 From: Christoph Hellwig To: James Bottomley Cc: atoth@atoth.sote.hu, aradford@gmail.com, linux-scsi@vger.kernel.org Subject: [PATCH] 3w-9xxx: don't unmap bounce buffered commands Date: Sat, 3 Oct 2015 19:16:07 +0200 Message-Id: <1443892567-9562-2-git-send-email-hch@lst.de> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1443892567-9562-1-git-send-email-hch@lst.de> References: <1443892567-9562-1-git-send-email-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 3w controller don't dma map small single SGL entry commands but instead bounce buffer them. Add a helper to identify these commands and don't call scsi_dma_unmap for them. Based on an earlier patch from James Bottomley. Fixes: 118c85 ("3w-9xxx: fix command completion race") Reported-by: T??th Attila Tested-by: T??th Attila Signed-off-by: Christoph Hellwig Acked-by: Adam Radford --- drivers/scsi/3w-9xxx.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c index add419d..a56a7b2 100644 --- a/drivers/scsi/3w-9xxx.c +++ b/drivers/scsi/3w-9xxx.c @@ -212,6 +212,17 @@ static const struct file_operations twa_fops = { .llseek = noop_llseek, }; +/* + * The controllers use an inline buffer instead of a mapped SGL for small, + * single entry buffers. Note that we treat a zero-length transfer like + * a mapped SGL. + */ +static bool twa_command_mapped(struct scsi_cmnd *cmd) +{ + return scsi_sg_count(cmd) != 1 || + scsi_bufflen(cmd) >= TW_MIN_SGL_LENGTH; +} + /* This function will complete an aen request from the isr */ static int twa_aen_complete(TW_Device_Extension *tw_dev, int request_id) { @@ -1339,7 +1350,8 @@ static irqreturn_t twa_interrupt(int irq, void *dev_instance) } /* Now complete the io */ - scsi_dma_unmap(cmd); + if (twa_command_mapped(cmd)) + scsi_dma_unmap(cmd); cmd->scsi_done(cmd); tw_dev->state[request_id] = TW_S_COMPLETED; twa_free_request_id(tw_dev, request_id); @@ -1582,7 +1594,8 @@ static int twa_reset_device_extension(TW_Device_Extension *tw_dev) struct scsi_cmnd *cmd = tw_dev->srb[i]; cmd->result = (DID_RESET << 16); - scsi_dma_unmap(cmd); + if (twa_command_mapped(cmd)) + scsi_dma_unmap(cmd); cmd->scsi_done(cmd); } } @@ -1765,12 +1778,14 @@ static int twa_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_ retval = twa_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL); switch (retval) { case SCSI_MLQUEUE_HOST_BUSY: - scsi_dma_unmap(SCpnt); + if (twa_command_mapped(SCpnt)) + scsi_dma_unmap(SCpnt); twa_free_request_id(tw_dev, request_id); break; case 1: SCpnt->result = (DID_ERROR << 16); - scsi_dma_unmap(SCpnt); + if (twa_command_mapped(SCpnt)) + scsi_dma_unmap(SCpnt); done(SCpnt); tw_dev->state[request_id] = TW_S_COMPLETED; twa_free_request_id(tw_dev, request_id); @@ -1831,8 +1846,7 @@ static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, /* Map sglist from scsi layer to cmd packet */ if (scsi_sg_count(srb)) { - if ((scsi_sg_count(srb) == 1) && - (scsi_bufflen(srb) < TW_MIN_SGL_LENGTH)) { + if (!twa_command_mapped(srb)) { if (srb->sc_data_direction == DMA_TO_DEVICE || srb->sc_data_direction == DMA_BIDIRECTIONAL) scsi_sg_copy_to_buffer(srb, @@ -1905,7 +1919,7 @@ static void twa_scsiop_execute_scsi_complete(TW_Device_Extension *tw_dev, int re { struct scsi_cmnd *cmd = tw_dev->srb[request_id]; - if (scsi_bufflen(cmd) < TW_MIN_SGL_LENGTH && + if (!twa_command_mapped(cmd) && (cmd->sc_data_direction == DMA_FROM_DEVICE || cmd->sc_data_direction == DMA_BIDIRECTIONAL)) { if (scsi_sg_count(cmd) == 1) {