From patchwork Wed Mar 6 19:56:06 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matt Porter X-Patchwork-Id: 2228011 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 583283FC8A for ; Wed, 6 Mar 2013 19:56:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754702Ab3CFTzn (ORCPT ); Wed, 6 Mar 2013 14:55:43 -0500 Received: from mail-ie0-f170.google.com ([209.85.223.170]:42227 "EHLO mail-ie0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754551Ab3CFTzm (ORCPT ); Wed, 6 Mar 2013 14:55:42 -0500 Received: by mail-ie0-f170.google.com with SMTP id c11so10189872ieb.29 for ; Wed, 06 Mar 2013 11:55:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:sender:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references; bh=s/N+gP6vGhP3ZtETry8cm4f/rrDttcmow2KGhs4SUPM=; b=jk3NQ0c5b3NleQ3LPaMmVnptS/YMh1+1/x0lv0mmhB7MvbkEDQOs5XW2l3vu/eOJvc Jt5bGwz20CC/ebgil7yFiL2QBtxyiTi6MFJPulYjRqRurm69FmYXEl9lwtFn/c4FNlLm b2yvSgtsfweutS2Mj9mecSfUEU60dmdSnW9mWE8LWtLVpZCs1pTbZ5zUA6WGvaHwf3x0 06+5bXMRT1YtVebsr4uVUhXcRGGlKKzmDk0Z4pPyvVozctFTdo2zR681MEbWy+nKMSme l1/NezgH/UG8Y/Sr8DwpEQ5viPcWetP9gdmByVBls5QcUScLBJ6Hyoh14TNac0l7fITV kIhA== X-Received: by 10.50.194.164 with SMTP id hx4mr11973706igc.35.1362599741722; Wed, 06 Mar 2013 11:55:41 -0800 (PST) Received: from beef.ohporter.com (cpe-98-27-254-98.neo.res.rr.com. [98.27.254.98]) by mx.google.com with ESMTPS id wx2sm25991191igb.4.2013.03.06.11.55.40 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 06 Mar 2013 11:55:41 -0800 (PST) From: Matt Porter To: Vinod Koul , Chris Ball Cc: Dan Williams , Sekhar Nori , Grant Likely , Linux DaVinci Kernel List , Linux Kernel Mailing List , Linux MMC List Subject: [PATCH v4 2/3] dma: edma: add device_slave_sg_limits() support Date: Wed, 6 Mar 2013 14:56:06 -0500 Message-Id: <1362599767-11292-3-git-send-email-mporter@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1362599767-11292-1-git-send-email-mporter@ti.com> References: <1362599767-11292-1-git-send-email-mporter@ti.com> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Implement device_slave_sg_limits(). EDMA has a finite set of PaRAM slots available for linking a multi-segment SG transfer. In order to prevent any one channel from consuming all PaRAM slots to fulfill a large SG transfer, the driver reports a static per-channel max number of SG segments it will handle. The maximum size of an SG segment is limited by the addr_width and maxburst of a given transfer request. These values are provided by the client driver and used to calculate and return the maximum segment length. Signed-off-by: Matt Porter --- drivers/dma/edma.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index cd7e328..42373bf 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -70,6 +70,7 @@ struct edma_chan { bool alloced; int slot[EDMA_MAX_SLOTS]; struct dma_slave_config cfg; + struct dma_slave_sg_limits sg_limits; }; struct edma_cc { @@ -462,6 +463,20 @@ static void edma_issue_pending(struct dma_chan *chan) spin_unlock_irqrestore(&echan->vchan.lock, flags); } +static struct dma_slave_sg_limits +*edma_get_slave_sg_limits(struct dma_chan *chan, + enum dma_slave_buswidth addr_width, + u32 maxburst) +{ + struct edma_chan *echan; + + echan = to_edma_chan(chan); + echan->sg_limits.max_seg_len = + (SZ_64K - 1) * addr_width * maxburst; + + return &echan->sg_limits; +} + static size_t edma_desc_size(struct edma_desc *edesc) { int i; @@ -521,6 +536,7 @@ static void __init edma_chan_init(struct edma_cc *ecc, echan->ch_num = EDMA_CTLR_CHAN(ecc->ctlr, i); echan->ecc = ecc; echan->vchan.desc_free = edma_desc_free; + echan->sg_limits.max_seg_nr = MAX_NR_SG; vchan_init(&echan->vchan, dma); @@ -537,6 +553,7 @@ static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma, dma->device_alloc_chan_resources = edma_alloc_chan_resources; dma->device_free_chan_resources = edma_free_chan_resources; dma->device_issue_pending = edma_issue_pending; + dma->device_slave_sg_limits = edma_get_slave_sg_limits; dma->device_tx_status = edma_tx_status; dma->device_control = edma_control; dma->dev = dev;