From patchwork Fri Jan 31 09:38:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Ujfalusi X-Patchwork-Id: 11359521 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 27DAF13B4 for ; Fri, 31 Jan 2020 09:38:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 051F320CC7 for ; Fri, 31 Jan 2020 09:38:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="XW6VOONy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728287AbgAaJiZ (ORCPT ); Fri, 31 Jan 2020 04:38:25 -0500 Received: from lelv0143.ext.ti.com ([198.47.23.248]:49868 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728237AbgAaJiX (ORCPT ); Fri, 31 Jan 2020 04:38:23 -0500 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 00V9cEHa094778; Fri, 31 Jan 2020 03:38:14 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1580463494; bh=ReMGt/DSeBN+XI+/pirRZxAFHoWdvXSVqCSKrKt1Fvk=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=XW6VOONynztS0wldIPlEf5yYr56TEPmkb6CazDQ7utz0nlaQ+ijsC/4LHigg+oO7S HLFMK7Cqe7LjEteHfXjMCDGnxzUtAkS3rJnCO2r8EbAiorDYTFx6/Z2Uch9OY17juM oeCSQfkdbvQMZFPIyADfcA9KtaefMcz/eSVzLQtA= Received: from DLEE103.ent.ti.com (dlee103.ent.ti.com [157.170.170.33]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 00V9cE7Q069223 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 31 Jan 2020 03:38:14 -0600 Received: from DLEE107.ent.ti.com (157.170.170.37) by DLEE103.ent.ti.com (157.170.170.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Fri, 31 Jan 2020 03:38:14 -0600 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE107.ent.ti.com (157.170.170.37) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Fri, 31 Jan 2020 03:38:14 -0600 Received: from feketebors.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 00V9cAGk054689; Fri, 31 Jan 2020 03:38:12 -0600 From: Peter Ujfalusi To: CC: , , , Subject: [PATCH v2 1/2] dmaengine: Cleanups for the slave <-> channel symlink support Date: Fri, 31 Jan 2020 11:38:58 +0200 Message-ID: <20200131093859.3311-2-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200131093859.3311-1-peter.ujfalusi@ti.com> References: <20200131093859.3311-1-peter.ujfalusi@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org No need to use goto to jump over the return chan ? chan : ERR_PTR(-EPROBE_DEFER); We can just revert the check and return right there. Do not fail the channel request if the chan->name allocation fails, but print a warning about it. Change the dev_err to dev_warn if sysfs_create_link() fails as it is not fatal. Only attempt to remove the DMA_SLAVE_NAME symlink if it is created - or it was attempted to be created. Signed-off-by: Peter Ujfalusi Reviewed-by: Geert Uytterhoeven --- drivers/dma/dmaengine.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 7b1cefc3213a..342d23132fca 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -756,22 +756,21 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name) } mutex_unlock(&dma_list_mutex); - if (!IS_ERR_OR_NULL(chan)) - goto found; - - return chan ? chan : ERR_PTR(-EPROBE_DEFER); + if (IS_ERR_OR_NULL(chan)) + return chan ? chan : ERR_PTR(-EPROBE_DEFER); found: - chan->slave = dev; chan->name = kasprintf(GFP_KERNEL, "dma:%s", name); if (!chan->name) - return ERR_PTR(-ENOMEM); + return chan; + chan->slave = dev; if (sysfs_create_link(&chan->dev->device.kobj, &dev->kobj, DMA_SLAVE_NAME)) - dev_err(dev, "Cannot create DMA %s symlink\n", DMA_SLAVE_NAME); + dev_warn(dev, "Cannot create DMA %s symlink\n", DMA_SLAVE_NAME); if (sysfs_create_link(&dev->kobj, &chan->dev->device.kobj, chan->name)) - dev_err(dev, "Cannot create DMA %s symlink\n", chan->name); + dev_warn(dev, "Cannot create DMA %s symlink\n", chan->name); + return chan; } EXPORT_SYMBOL_GPL(dma_request_chan); @@ -830,13 +829,14 @@ void dma_release_channel(struct dma_chan *chan) /* drop PRIVATE cap enabled by __dma_request_channel() */ if (--chan->device->privatecnt == 0) dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask); + if (chan->slave) { + sysfs_remove_link(&chan->dev->device.kobj, DMA_SLAVE_NAME); sysfs_remove_link(&chan->slave->kobj, chan->name); kfree(chan->name); chan->name = NULL; chan->slave = NULL; } - sysfs_remove_link(&chan->dev->device.kobj, DMA_SLAVE_NAME); mutex_unlock(&dma_list_mutex); } EXPORT_SYMBOL_GPL(dma_release_channel); From patchwork Fri Jan 31 09:38:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Ujfalusi X-Patchwork-Id: 11359519 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 814B3921 for ; Fri, 31 Jan 2020 09:38:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54FDD20CC7 for ; Fri, 31 Jan 2020 09:38:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="lHGTLPew" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728299AbgAaJiX (ORCPT ); Fri, 31 Jan 2020 04:38:23 -0500 Received: from fllv0016.ext.ti.com ([198.47.19.142]:49318 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728287AbgAaJiW (ORCPT ); Fri, 31 Jan 2020 04:38:22 -0500 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 00V9cG9h062891; Fri, 31 Jan 2020 03:38:16 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1580463496; bh=9TngcuOhfMZbaWeTL28TLmvKTUEs6RWhGH7o8O7jm4o=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=lHGTLPewwf/NR4DMB0lA1iP3tfGZdY3B0IS6AfDkZUyZ3OSFQDPuqsiO6urgjkgiQ x4S++uwHQgCNvqSJKcGpV7ceBfzMTaJYlJanB5mMfGKgpkoKh27EYdgTuHmMReCwRo p5CL1UEmWCQDTqMdiedWyjhOBtLFRKVYaVSleQVA= Received: from DLEE103.ent.ti.com (dlee103.ent.ti.com [157.170.170.33]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 00V9cGta069275 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 31 Jan 2020 03:38:16 -0600 Received: from DLEE106.ent.ti.com (157.170.170.36) by DLEE103.ent.ti.com (157.170.170.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Fri, 31 Jan 2020 03:38:16 -0600 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE106.ent.ti.com (157.170.170.36) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Fri, 31 Jan 2020 03:38:15 -0600 Received: from feketebors.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 00V9cAGl054689; Fri, 31 Jan 2020 03:38:14 -0600 From: Peter Ujfalusi To: CC: , , , Subject: [PATCH v2 2/2] dmaengine: Add basic debugfs support Date: Fri, 31 Jan 2020 11:38:59 +0200 Message-ID: <20200131093859.3311-3-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200131093859.3311-1-peter.ujfalusi@ti.com> References: <20200131093859.3311-1-peter.ujfalusi@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org Via the /sys/kernel/debug/dmaengine users can get information about the DMA devices and the used channels. Example output on am654-evm with audio using two channels and after running dmatest on 6 channels: # cat /sys/kernel/debug/dmaengine dma0 (285c0000.dma-controller): number of channels: 96 dma1 (31150000.dma-controller): number of channels: 267 dma1chan0: 2b00000.mcasp:tx dma1chan1: 2b00000.mcasp:rx dma1chan2: in-use dma1chan3: in-use dma1chan4: in-use dma1chan5: in-use dma1chan6: in-use dma1chan7: in-use For slave channels we can show the device and the channel name a given channel is requested. For non slave devices the only information we know is that the channel is in use. DMA drivers can implement the optional dbg_show callback to provide controller specific information instead of the generic one. It is easy to extend the generic dmaengine_dbg_show() to print additional information about the used channels. I have taken the idea from gpiolib. Signed-off-by: Peter Ujfalusi --- drivers/dma/dmaengine.c | 66 +++++++++++++++++++++++++++++++++++++++ include/linux/dmaengine.h | 12 ++++++- 2 files changed, 77 insertions(+), 1 deletion(-) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 342d23132fca..121231300d35 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -32,6 +32,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include #include #include @@ -760,6 +761,11 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name) return chan ? chan : ERR_PTR(-EPROBE_DEFER); found: +#ifdef CONFIG_DEBUG_FS + chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev), + name); +#endif + chan->name = kasprintf(GFP_KERNEL, "dma:%s", name); if (!chan->name) return chan; @@ -837,6 +843,11 @@ void dma_release_channel(struct dma_chan *chan) chan->name = NULL; chan->slave = NULL; } + +#ifdef CONFIG_DEBUG_FS + kfree(chan->dbg_client_name); + chan->dbg_client_name = NULL; +#endif mutex_unlock(&dma_list_mutex); } EXPORT_SYMBOL_GPL(dma_release_channel); @@ -1559,3 +1570,58 @@ static int __init dma_bus_init(void) return class_register(&dma_devclass); } arch_initcall(dma_bus_init); + +#ifdef CONFIG_DEBUG_FS +static void dmaengine_dbg_show(struct seq_file *s, struct dma_device *dma_dev) +{ + struct dma_chan *chan; + + list_for_each_entry(chan, &dma_dev->channels, device_node) { + if (chan->client_count) { + seq_printf(s, " dma%dchan%-4d| %s", + dma_dev->dev_id, chan->chan_id, + chan->dbg_client_name ?: "in-use"); + + if (chan->router) + seq_printf(s, " (via router: %s)\n", + dev_name(chan->router->dev)); + else + seq_puts(s, "\n"); + } + } +} + +static int dmaengine_debugfs_show(struct seq_file *s, void *data) +{ + struct dma_device *dma_dev = NULL; + + mutex_lock(&dma_list_mutex); + list_for_each_entry(dma_dev, &dma_device_list, global_node) { + seq_printf(s, "dma%d (%s): number of channels: %u\n", + dma_dev->dev_id, dev_name(dma_dev->dev), + dma_dev->chancnt); + + if (dma_dev->dbg_show) + dma_dev->dbg_show(s, dma_dev); + else + dmaengine_dbg_show(s, dma_dev); + + if (!list_is_last(&dma_dev->global_node, &dma_device_list)) + seq_puts(s, "\n"); + } + mutex_unlock(&dma_list_mutex); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(dmaengine_debugfs); + +static int __init dmaengine_debugfs_init(void) +{ + /* /sys/kernel/debug/dmaengine */ + debugfs_create_file("dmaengine", 0444, NULL, NULL, + &dmaengine_debugfs_fops); + return 0; +} +late_initcall(dmaengine_debugfs_init); + +#endif /* DEBUG_FS */ diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 64461fc64e1b..9f232b7618f1 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -300,6 +300,8 @@ struct dma_router { * @chan_id: channel ID for sysfs * @dev: class device for sysfs * @name: backlink name for sysfs + * @dbg_client_name: slave name for debugfs in format: + * dev_name(requester's dev):channel name, for example: "2b00000.mcasp:tx" * @device_node: used to add this to the device chan list * @local: per-cpu pointer to a struct dma_chan_percpu * @client_count: how many clients are using this channel @@ -318,6 +320,9 @@ struct dma_chan { int chan_id; struct dma_chan_dev *dev; const char *name; +#ifdef CONFIG_DEBUG_FS + char *dbg_client_name; +#endif struct list_head device_node; struct dma_chan_percpu __percpu *local; @@ -805,7 +810,9 @@ struct dma_filter { * called and there are no further references to this structure. This * must be implemented to free resources however many existing drivers * do not and are therefore not safe to unbind while in use. - * + * @dbg_show: optional routine to show contents in debugfs; default code + * will be used when this is omitted, but custom code can show extra, + * controller specific information. */ struct dma_device { struct kref ref; @@ -891,6 +898,9 @@ struct dma_device { struct dma_tx_state *txstate); void (*device_issue_pending)(struct dma_chan *chan); void (*device_release)(struct dma_device *dev); +#ifdef CONFIG_DEBUG_FS + void (*dbg_show)(struct seq_file *s, struct dma_device *dev); +#endif }; static inline int dmaengine_slave_config(struct dma_chan *chan,