From patchwork Fri Feb 28 13:07:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Ujfalusi X-Patchwork-Id: 11412217 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 E466D138D for ; Fri, 28 Feb 2020 13:08:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA7DC246AF for ; Fri, 28 Feb 2020 13:08:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="XpPA8fA1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726674AbgB1NIC (ORCPT ); Fri, 28 Feb 2020 08:08:02 -0500 Received: from lelv0142.ext.ti.com ([198.47.23.249]:38570 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725769AbgB1NIB (ORCPT ); Fri, 28 Feb 2020 08:08:01 -0500 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 01SD7pZQ011550; Fri, 28 Feb 2020 07:07:51 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1582895271; bh=42Kd2NmuD2KX5smzhDQPlg7uqqCq2Ohxi2uxGYOlrRk=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=XpPA8fA1N6ZSydpnC6AxKKDXVAmASiKzjM2GQCdYJsbTa+tSzv1HF6GvJf4Gie972 rHRimTp+LTBSxuaAHjIHKHmHxN425Y4HROUyPXxjlnq9O66T38RlRtGXxIcJwaT2iA +bdmnNwxUILjWDcupmgrJVOApvVVWUwIYqMzNf4Q= Received: from DFLE104.ent.ti.com (dfle104.ent.ti.com [10.64.6.25]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id 01SD7prU105541; Fri, 28 Feb 2020 07:07:51 -0600 Received: from DFLE101.ent.ti.com (10.64.6.22) by DFLE104.ent.ti.com (10.64.6.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Fri, 28 Feb 2020 07:07:51 -0600 Received: from localhost.localdomain (10.64.41.19) by DFLE101.ent.ti.com (10.64.6.22) 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, 28 Feb 2020 07:07:51 -0600 Received: from feketebors.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by localhost.localdomain (8.15.2/8.15.2) with ESMTP id 01SD7lct037330; Fri, 28 Feb 2020 07:07:50 -0600 From: Peter Ujfalusi To: CC: , , , Subject: [PATCH v4 1/2] dmaengine: Add basic debugfs support Date: Fri, 28 Feb 2020 15:07:46 +0200 Message-ID: <20200228130747.22905-2-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200228130747.22905-1-peter.ujfalusi@ti.com> References: <20200228130747.22905-1-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/summary 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 4 channels: 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 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_summary_show callback to provide controller specific information instead of the generic one. It is easy to extend the generic dmaengine_summary_show() to print additional information about the used channels. In case DMA drivers want to create additional files under the dmaengine directory to provide additional debug points, they can use the dmaengine_get_debugfs_root() to get the dentry of the rootdir. I have taken the idea from gpiolib and clk subsystems. Signed-off-by: Peter Ujfalusi --- drivers/dma/dmaengine.c | 77 +++++++++++++++++++++++++++++++++++++++ drivers/dma/dmaengine.h | 6 +++ include/linux/dmaengine.h | 12 +++++- 3 files changed, 94 insertions(+), 1 deletion(-) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index c3b1283b6d31..b5e8b737785c 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -760,6 +760,11 @@ 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 +842,11 @@ 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); @@ -1562,3 +1572,70 @@ static int __init dma_bus_init(void) return class_register(&dma_devclass); } arch_initcall(dma_bus_init); + +#ifdef CONFIG_DEBUG_FS +#include + +static struct dentry *rootdir; + +struct dentry *dmaengine_get_debugfs_root(void) +{ + return rootdir; +} +EXPORT_SYMBOL_GPL(dmaengine_get_debugfs_root); + +static void dmaengine_dbg_summary_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, " %-13s| %s", dma_chan_name(chan), + 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_summary_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_summary_show) + dma_dev->dbg_summary_show(s, dma_dev); + else + dmaengine_dbg_summary_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_summary); + +static int __init dmaengine_debugfs_init(void) +{ + rootdir = debugfs_create_dir("dmaengine", NULL); + + /* /sys/kernel/debug/dmaengine */ + debugfs_create_file("summary", 0444, rootdir, NULL, + &dmaengine_summary_fops); + return 0; +} +late_initcall(dmaengine_debugfs_init); + +#endif /* DEBUG_FS */ diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h index e8a320c9e57c..72cd7fe33638 100644 --- a/drivers/dma/dmaengine.h +++ b/drivers/dma/dmaengine.h @@ -182,4 +182,10 @@ dmaengine_desc_callback_valid(struct dmaengine_desc_callback *cb) struct dma_chan *dma_get_slave_channel(struct dma_chan *chan); struct dma_chan *dma_get_any_slave_channel(struct dma_device *device); +#ifdef CONFIG_DEBUG_FS +#include + +struct dentry *dmaengine_get_debugfs_root(void); +#endif + #endif diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 64461fc64e1b..a0fff2f9f3b5 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_summary_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_summary_show)(struct seq_file *s, struct dma_device *dev); +#endif }; static inline int dmaengine_slave_config(struct dma_chan *chan,