From patchwork Wed Aug 7 10:19:19 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Mack X-Patchwork-Id: 2840117 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id E5AFE9F479 for ; Wed, 7 Aug 2013 10:21:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A5769201E1 for ; Wed, 7 Aug 2013 10:21:53 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4652A201CD for ; Wed, 7 Aug 2013 10:21:51 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1V70rX-0002OG-V4; Wed, 07 Aug 2013 10:21:04 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1V70rF-0003Hh-MA; Wed, 07 Aug 2013 10:20:45 +0000 Received: from svenfoo.org ([82.94.215.22] helo=mail.zonque.de) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1V70qW-0003B5-9E for linux-arm-kernel@lists.infradead.org; Wed, 07 Aug 2013 10:20:03 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.zonque.de (Postfix) with ESMTP id A7408C059B; Wed, 7 Aug 2013 12:19:37 +0200 (CEST) Received: from mail.zonque.de ([127.0.0.1]) by localhost (rambrand.bugwerft.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Q3FSLw8Wra6I; Wed, 7 Aug 2013 12:19:37 +0200 (CEST) Received: from tamtam.fritz.box (p5DDC7ADB.dip0.t-ipconnect.de [93.220.122.219]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.zonque.de (Postfix) with ESMTPSA id B33D5C0599; Wed, 7 Aug 2013 12:19:36 +0200 (CEST) From: Daniel Mack To: vinod.koul@intel.com, djbw@fb.com Subject: [PATCH 01/12] dma: mmp_pdma: add protect when alloc/free phy channels Date: Wed, 7 Aug 2013 12:19:19 +0200 Message-Id: <1375870770-14263-2-git-send-email-zonque@gmail.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1375870770-14263-1-git-send-email-zonque@gmail.com> References: <1375870770-14263-1-git-send-email-zonque@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130807_062000_686739_E4265557 X-CRM114-Status: GOOD ( 13.41 ) X-Spam-Score: -0.2 (/) Cc: wangx@marvell.com, eric.y.miao@gmail.com, nico@fluxnic.net, haojian.zhuang@gmail.com, cxie4@marvell.com, ezequiel.garcia@free-electrons.com, linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, FREEMAIL_FROM,RCVD_IN_DNSWL_MED,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 From: Xiang Wang In mmp pdma, phy channels are allocated/freed dynamically and frequently. But no proper protection is added. Conflict will happen when multi-users are requesting phy channels at the same time. Use spinlock to protect. Signed-off-by: Xiang Wang --- drivers/dma/mmp_pdma.c | 42 ++++++++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 16 deletions(-) diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index c26699f..226158d 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -121,6 +121,7 @@ struct mmp_pdma_device { struct device *dev; struct dma_device device; struct mmp_pdma_phy *phy; + spinlock_t phy_lock; /* protect alloc/free phy channels */ }; #define tx_to_mmp_pdma_desc(tx) container_of(tx, struct mmp_pdma_desc_sw, async_tx) @@ -219,6 +220,7 @@ static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan) int prio, i; struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device); struct mmp_pdma_phy *phy; + unsigned long flags; /* * dma channel priorities @@ -227,6 +229,8 @@ static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan) * ch 8 - 11, 24 - 27 <--> (2) * ch 12 - 15, 28 - 31 <--> (3) */ + + spin_lock_irqsave(&pdev->phy_lock, flags); for (prio = 0; prio <= (((pdev->dma_channels - 1) & 0xf) >> 2); prio++) { for (i = 0; i < pdev->dma_channels; i++) { if (prio != ((i & 0xf) >> 2)) @@ -234,14 +238,30 @@ static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan) phy = &pdev->phy[i]; if (!phy->vchan) { phy->vchan = pchan; + spin_unlock_irqrestore(&pdev->phy_lock, flags); return phy; } } } + spin_unlock_irqrestore(&pdev->phy_lock, flags); return NULL; } +static void mmp_pdma_free_phy(struct mmp_pdma_chan *pchan) +{ + struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device); + unsigned long flags; + + if (!pchan->phy) + return; + + spin_lock_irqsave(&pdev->phy_lock, flags); + pchan->phy->vchan = NULL; + pchan->phy = NULL; + spin_unlock_irqrestore(&pdev->phy_lock, flags); +} + /* desc->tx_list ==> pending list */ static void append_pending_queue(struct mmp_pdma_chan *chan, struct mmp_pdma_desc_sw *desc) @@ -277,10 +297,7 @@ static void start_pending_queue(struct mmp_pdma_chan *chan) if (list_empty(&chan->chain_pending)) { /* chance to re-fetch phy channel with higher prio */ - if (chan->phy) { - chan->phy->vchan = NULL; - chan->phy = NULL; - } + mmp_pdma_free_phy(chan); dev_dbg(chan->dev, "no pending list\n"); return; } @@ -377,10 +394,7 @@ static int mmp_pdma_alloc_chan_resources(struct dma_chan *dchan) dev_err(chan->dev, "unable to allocate descriptor pool\n"); return -ENOMEM; } - if (chan->phy) { - chan->phy->vchan = NULL; - chan->phy = NULL; - } + mmp_pdma_free_phy(chan); chan->idle = true; chan->dev_addr = 0; return 1; @@ -411,10 +425,7 @@ static void mmp_pdma_free_chan_resources(struct dma_chan *dchan) chan->desc_pool = NULL; chan->idle = true; chan->dev_addr = 0; - if (chan->phy) { - chan->phy->vchan = NULL; - chan->phy = NULL; - } + mmp_pdma_free_phy(chan); return; } @@ -581,10 +592,7 @@ static int mmp_pdma_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd, switch (cmd) { case DMA_TERMINATE_ALL: disable_chan(chan->phy); - if (chan->phy) { - chan->phy->vchan = NULL; - chan->phy = NULL; - } + mmp_pdma_free_phy(chan); spin_lock_irqsave(&chan->desc_lock, flags); mmp_pdma_free_desc_list(chan, &chan->chain_pending); mmp_pdma_free_desc_list(chan, &chan->chain_running); @@ -777,6 +785,8 @@ static int mmp_pdma_probe(struct platform_device *op) return -ENOMEM; pdev->dev = &op->dev; + spin_lock_init(&pdev->phy_lock); + iores = platform_get_resource(op, IORESOURCE_MEM, 0); if (!iores) return -EINVAL;