From patchwork Wed Jul 4 16:17:42 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guennadi Liakhovetski X-Patchwork-Id: 1157011 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 696073FE4F for ; Wed, 4 Jul 2012 16:18:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755296Ab2GDQR6 (ORCPT ); Wed, 4 Jul 2012 12:17:58 -0400 Received: from moutng.kundenserver.de ([212.227.126.186]:63920 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754810Ab2GDQRs (ORCPT ); Wed, 4 Jul 2012 12:17:48 -0400 Received: from axis700.grange (dslb-188-109-038-248.pools.arcor-ip.net [188.109.38.248]) by mrelayeu.kundenserver.de (node=mrbap4) with ESMTP (Nemesis) id 0MIw2b-1SovFB2kxN-002Uj6; Wed, 04 Jul 2012 18:17:45 +0200 Received: from 6a.grange (6a.grange [192.168.1.11]) by axis700.grange (Postfix) with ESMTPS id 2633118B06F; Wed, 4 Jul 2012 18:17:44 +0200 (CEST) Received: from lyakh by 6a.grange with local (Exim 4.72) (envelope-from ) id 1SmSGt-0006Mj-UG; Wed, 04 Jul 2012 18:17:43 +0200 From: Guennadi Liakhovetski To: Vinod Koul Cc: Magnus Damm , linux-sh@vger.kernel.org, linux-mmc@vger.kernel.org, Chris Ball , linux-kernel@vger.kernel.org Subject: [PATCH 3/4] dma: sh: provide a migration path for slave drivers to stop using .private Date: Wed, 4 Jul 2012 18:17:42 +0200 Message-Id: <1341418663-24432-4-git-send-email-g.liakhovetski@gmx.de> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1341418663-24432-1-git-send-email-g.liakhovetski@gmx.de> References: <1341418663-24432-1-git-send-email-g.liakhovetski@gmx.de> X-Provags-ID: V02:K0:NpUH/R2Xxbj1qMKhjUk8X0G6W/vGsdnR7y6VN89T+Fu 4eftY/c0Du2AoBxImDaZtFWPtjPy1KLrmfM2J9uiYTf/QB0995 9Hq/VQdtkLC8Gn8PipHad8BVZqgwM8r5B0mrucY/E1PvK32hTh g14KleyVNFMcMniZk0vT8ACBeteF0Kx6L7T3iUGWwF8J96OaIq m3Hfk1slo80aXm2VcrRr1E/ebkWu5GTkjPIsN2wfQ7fnGAbr9R Eo0Fr99qlNt/FmsaMYX7Iy0CbTVijDr3BU64ku2Vos2Qvpr1/N C8DG1tIYJ3mZB7cIqKnEqiv2KwiCw5gx+3xkRLG0sVPio1gr6w LcubHrKBI79P8HpUR8c9wb3C7cciTMJvON5cnxT1xeEe9tTovr 1CJ5zsofFvNPQ== Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org This patch extends the sh dmaengine driver to support the preferred channel selection and configuration method, instead of using the "private" field from struct dma_chan. We add a standard filter function to be used by slave drivers instead of implementing their own ones, and add support for the DMA_SLAVE_CONFIG control operation, which must accompany the new channel selection method. We still support the legacy .private channel allocation method to cater for a smooth driver migration. Signed-off-by: Guennadi Liakhovetski --- drivers/dma/sh/shdma-base.c | 114 +++++++++++++++++++++++++++++++++--------- drivers/dma/sh/shdma.c | 5 +- include/linux/sh_dma.h | 2 + include/linux/shdma-base.h | 2 +- 4 files changed, 95 insertions(+), 28 deletions(-) diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c index 73db282..0c34c73 100644 --- a/drivers/dma/sh/shdma-base.c +++ b/drivers/dma/sh/shdma-base.c @@ -171,6 +171,65 @@ static struct shdma_desc *shdma_get_desc(struct shdma_chan *schan) return NULL; } +static int shdma_setup_slave(struct shdma_chan *schan, int slave_id) +{ + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + int ret; + + if (slave_id < 0 || slave_id >= slave_num) + return -EINVAL; + + if (test_and_set_bit(slave_id, shdma_slave_used)) + return -EBUSY; + + ret = ops->set_slave(schan, slave_id, false); + if (ret < 0) { + clear_bit(slave_id, shdma_slave_used); + return ret; + } + + schan->slave_id = slave_id; + + return 0; +} + +/* + * This is the standard shdma filter function to be used as a replacement to the + * "old" method, using the .private pointer. If for some reason you allocate a + * channel without slave data, use something like ERR_PTR(-EINVAL) as a filter + * parameter. If this filter is used, the slave driver, after calling + * dma_request_channel(), will also have to call dmaengine_slave_config() with + * .slave_id, .direction, and either .src_addr or .dst_addr set. + * NOTE: this filter doesn't support multiple DMAC drivers with the DMA_SLAVE + * capability! If this becomes a requirement, hardware glue drivers, using this + * services would have to provide their own filters, which first would check + * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do + * this, and only then, in case of a match, call this common filter. + */ +bool shdma_chan_filter(struct dma_chan *chan, void *arg) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + int slave_id = (int)arg; + int ret; + + if (slave_id < 0) + /* No slave requested - arbitrary channel */ + return true; + + if (slave_id >= slave_num) + return false; + + ret = ops->set_slave(schan, slave_id, true); + if (ret < 0) + return false; + + return true; +} +EXPORT_SYMBOL(shdma_chan_filter); + static int shdma_alloc_chan_resources(struct dma_chan *chan) { struct shdma_chan *schan = to_shdma_chan(chan); @@ -185,21 +244,10 @@ static int shdma_alloc_chan_resources(struct dma_chan *chan) * never runs concurrently with itself or free_chan_resources. */ if (slave) { - if (slave->slave_id < 0 || slave->slave_id >= slave_num) { - ret = -EINVAL; - goto evalid; - } - - if (test_and_set_bit(slave->slave_id, shdma_slave_used)) { - ret = -EBUSY; - goto etestused; - } - - ret = ops->set_slave(schan, slave->slave_id); + /* Legacy mode: .private is set in filter */ + ret = shdma_setup_slave(schan, slave->slave_id); if (ret < 0) goto esetslave; - - schan->slave_id = slave->slave_id; } else { schan->slave_id = -EINVAL; } @@ -228,8 +276,6 @@ edescalloc: if (slave) esetslave: clear_bit(slave->slave_id, shdma_slave_used); -etestused: -evalid: chan->private = NULL; return ret; } @@ -587,22 +633,40 @@ static int shdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, struct shdma_chan *schan = to_shdma_chan(chan); struct shdma_dev *sdev = to_shdma_dev(chan->device); const struct shdma_ops *ops = sdev->ops; + struct dma_slave_config *config; unsigned long flags; - - /* Only supports DMA_TERMINATE_ALL */ - if (cmd != DMA_TERMINATE_ALL) - return -ENXIO; + int ret; if (!chan) return -EINVAL; - spin_lock_irqsave(&schan->chan_lock, flags); - - ops->halt_channel(schan); - - spin_unlock_irqrestore(&schan->chan_lock, flags); + switch (cmd) { + case DMA_TERMINATE_ALL: + spin_lock_irqsave(&schan->chan_lock, flags); + ops->halt_channel(schan); + spin_unlock_irqrestore(&schan->chan_lock, flags); - shdma_chan_ld_cleanup(schan, true); + shdma_chan_ld_cleanup(schan, true); + break; + case DMA_SLAVE_CONFIG: + /* + * So far only .slave_id is used, but the slave drivers are + * encouraged to also set a transfer direction and an address. + */ + if (!arg) + return -EINVAL; + /* + * We could lock this, but you shouldn't be configuring the + * channel, while using it... + */ + config = (struct dma_slave_config*)arg; + ret = shdma_setup_slave(schan, config->slave_id); + if (ret < 0) + return ret; + break; + default: + return -ENXIO; + } return 0; } diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c index 9a10d8b..027c9be 100644 --- a/drivers/dma/sh/shdma.c +++ b/drivers/dma/sh/shdma.c @@ -320,7 +320,7 @@ static const struct sh_dmae_slave_config *dmae_find_slave( } static int sh_dmae_set_slave(struct shdma_chan *schan, - int slave_id) + int slave_id, bool try) { struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan, shdma_chan); @@ -328,7 +328,8 @@ static int sh_dmae_set_slave(struct shdma_chan *schan, if (!cfg) return -ENODEV; - sh_chan->config = cfg; + if (!try) + sh_chan->config = cfg; return 0; } diff --git a/include/linux/sh_dma.h b/include/linux/sh_dma.h index 4e83f3e..b64d6be 100644 --- a/include/linux/sh_dma.h +++ b/include/linux/sh_dma.h @@ -99,4 +99,6 @@ struct sh_dmae_pdata { #define CHCR_TE 0x00000002 #define CHCR_IE 0x00000004 +bool shdma_chan_filter(struct dma_chan *chan, void *arg); + #endif diff --git a/include/linux/shdma-base.h b/include/linux/shdma-base.h index 6263ad2..93f9821 100644 --- a/include/linux/shdma-base.h +++ b/include/linux/shdma-base.h @@ -93,7 +93,7 @@ struct shdma_ops { dma_addr_t (*slave_addr)(struct shdma_chan *); int (*desc_setup)(struct shdma_chan *, struct shdma_desc *, dma_addr_t, dma_addr_t, size_t *); - int (*set_slave)(struct shdma_chan *, int); + int (*set_slave)(struct shdma_chan *, int, bool); void (*setup_xfer)(struct shdma_chan *, int); void (*start_xfer)(struct shdma_chan *, struct shdma_desc *); struct shdma_desc *(*embedded_desc)(void *, int);