From patchwork Fri May 5 09:57:48 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Petazzoni X-Patchwork-Id: 9713335 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D809960235 for ; Fri, 5 May 2017 10:26:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BC2402867A for ; Fri, 5 May 2017 10:26:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AFC322867C; Fri, 5 May 2017 10:26:12 +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=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2C6E62867A for ; Fri, 5 May 2017 10:26:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=Y8BARdgRwBeJoRtA0OnVpEfuWv21nV0Sgy6SOeMDjhk=; b=WqpI6rlACETKtaoFH076OSiiGp P+fGmAsRiruF+xlLk4pIn58c36VSlrpnofkFsYFt024UxGnjP5c1FWLCE9L06l0BYfCjf12HiAooe Pmd96GX7onN7nSazIzygGGRuqOwicQ9RFDbnakknCRR/0LMIZA19UHcsAAcBhUzVmnSi6mIafXgpk XslWGesVhMs8cEQ9OmfJV2GMToXmUGdUHiHRdxwxKg4svfuYqb+PDSpCX1tBdt3yn/RuTZMNXzESK i4RuX9VRZEOxHfLY0d/D9jjJhSgzXAiEpNZjiQPoIpBt8Vd/+cWu18esKVxWzQQi8yKNkv6QORZeC VPhyuxdg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1d6aR9-00025K-HD; Fri, 05 May 2017 10:26:11 +0000 Received: from mail.free-electrons.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1d6a0X-0002Ws-Cx for linux-arm-kernel@lists.infradead.org; Fri, 05 May 2017 09:58:54 +0000 Received: by mail.free-electrons.com (Postfix, from userid 110) id 157E0212EB; Fri, 5 May 2017 11:57:58 +0200 (CEST) Received: from localhost (LStLambert-657-1-97-87.w90-63.abo.wanadoo.fr [90.63.216.87]) by mail.free-electrons.com (Postfix) with ESMTPSA id E37B7206EF; Fri, 5 May 2017 11:57:57 +0200 (CEST) From: Thomas Petazzoni To: Vinod Koul , dmaengine@vger.kernel.org Subject: [PATCH 05/10] dma: mv_xor_v2: fix tx_submit() implementation Date: Fri, 5 May 2017 11:57:48 +0200 Message-Id: <1493978274-12805-6-git-send-email-thomas.petazzoni@free-electrons.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1493978274-12805-1-git-send-email-thomas.petazzoni@free-electrons.com> References: <1493978274-12805-1-git-send-email-thomas.petazzoni@free-electrons.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170505_025842_653685_C79B2AFB X-CRM114-Status: GOOD ( 13.70 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Petazzoni , Andrew Lunn , Yehuda Yitschak , Jason Cooper , Hanna Hawa , stable@vger.kernel.org, Nadav Haklai , Gregory Clement , linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The mv_xor_v2_tx_submit() gets the next available HW descriptor by calling mv_xor_v2_get_desq_write_ptr(), which reads a HW register telling the next available HW descriptor. This was working fine when HW descriptors were issued for processing directly in tx_submit(). However, as part of the review process of the driver, a change was requested to move the actual kick-off of HW descriptors processing to ->issue_pending(). Due to this, reading the HW register to know the next available HW descriptor no longer works. So instead of using this HW register, we implemented a software index pointing to the next available HW descriptor. Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver") Cc: Signed-off-by: Thomas Petazzoni --- drivers/dma/mv_xor_v2.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-) diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c index 211b8c0..4684ece 100644 --- a/drivers/dma/mv_xor_v2.c +++ b/drivers/dma/mv_xor_v2.c @@ -161,6 +161,7 @@ struct mv_xor_v2_device { struct mv_xor_v2_sw_desc *sw_desq; int desc_size; unsigned int npendings; + unsigned int hw_queue_idx; }; /** @@ -214,18 +215,6 @@ static void mv_xor_v2_set_data_buffers(struct mv_xor_v2_device *xor_dev, } /* - * Return the next available index in the DESQ. - */ -static int mv_xor_v2_get_desq_write_ptr(struct mv_xor_v2_device *xor_dev) -{ - /* read the index for the next available descriptor in the DESQ */ - u32 reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ALLOC_OFF); - - return ((reg >> MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_SHIFT) - & MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_MASK); -} - -/* * notify the engine of new descriptors, and update the available index. */ static void mv_xor_v2_add_desc_to_desq(struct mv_xor_v2_device *xor_dev, @@ -306,7 +295,6 @@ static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data) static dma_cookie_t mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx) { - int desq_ptr; void *dest_hw_desc; dma_cookie_t cookie; struct mv_xor_v2_sw_desc *sw_desc = @@ -322,15 +310,15 @@ mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx) spin_lock_bh(&xor_dev->lock); cookie = dma_cookie_assign(tx); - /* get the next available slot in the DESQ */ - desq_ptr = mv_xor_v2_get_desq_write_ptr(xor_dev); - /* copy the HW descriptor from the SW descriptor to the DESQ */ - dest_hw_desc = xor_dev->hw_desq_virt + desq_ptr; + dest_hw_desc = xor_dev->hw_desq_virt + xor_dev->hw_queue_idx; memcpy(dest_hw_desc, &sw_desc->hw_desc, xor_dev->desc_size); xor_dev->npendings++; + xor_dev->hw_queue_idx++; + if (xor_dev->hw_queue_idx >= MV_XOR_V2_DESC_NUM) + xor_dev->hw_queue_idx = 0; spin_unlock_bh(&xor_dev->lock);