From patchwork Thu Jan 30 11:42:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Ujfalusi X-Patchwork-Id: 11357791 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 8CB2092A for ; Thu, 30 Jan 2020 11:41:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 603FA20CC7 for ; Thu, 30 Jan 2020 11:41:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="iYEDvFcQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727112AbgA3Llp (ORCPT ); Thu, 30 Jan 2020 06:41:45 -0500 Received: from lelv0142.ext.ti.com ([198.47.23.249]:37446 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727107AbgA3Llo (ORCPT ); Thu, 30 Jan 2020 06:41:44 -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 00UBfc5p039522; Thu, 30 Jan 2020 05:41:38 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1580384498; bh=nOaK30hKcU0nHopMIcNcNAI7Bta7pqRO8AZ6vId2DZU=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=iYEDvFcQ1/K+Xei33XXarqTk2bXsPv6Meu3Q+Fq4bt1TwJJwidwjI6nwQgYz2AS6t nCMmEbdIpnVJzX5i+etGWlch5N0I+txNPEYv5xyRZ6L2LFXXfRWYU8Mh84fHAMTOwy UPT/w4MdxQ/YFcnz4vezisOhneFcjnsLlTWGMvDo= Received: from DLEE106.ent.ti.com (dlee106.ent.ti.com [157.170.170.36]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id 00UBfcUf008738; Thu, 30 Jan 2020 05:41:38 -0600 Received: from DLEE101.ent.ti.com (157.170.170.31) 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; Thu, 30 Jan 2020 05:41:37 -0600 Received: from lelv0326.itg.ti.com (10.180.67.84) by DLEE101.ent.ti.com (157.170.170.31) 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; Thu, 30 Jan 2020 05:41:38 -0600 Received: from feketebors.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 00UBfW7Y104655; Thu, 30 Jan 2020 05:41:36 -0600 From: Peter Ujfalusi To: CC: , , , Subject: [PATCH 2/2] dmaengine: Add basic debugfs support Date: Thu, 30 Jan 2020 13:42:20 +0200 Message-ID: <20200130114220.23538-3-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200130114220.23538-1-peter.ujfalusi@ti.com> References: <20200130114220.23538-1-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 | 120 ++++++++++++++++++++++++++++++++++++++ include/linux/dmaengine.h | 12 +++- 2 files changed, 131 insertions(+), 1 deletion(-) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 75516f9fbab4..7573a4d0f9d7 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 +761,13 @@ 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->slave_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev), name); + if (!chan->slave_name) + dev_warn(dev, + "Cannot allocate memory for slave name (debugfs)\n"); +#endif + chan->name = kasprintf(GFP_KERNEL, "dma:%s", name); if (!chan->name) { dev_warn(dev, @@ -840,6 +848,13 @@ void dma_release_channel(struct dma_chan *chan) chan->name = NULL; chan->slave = NULL; } + +#ifdef CONFIG_DEBUG_FS + if (chan->slave_name) { + kfree(chan->slave_name); + chan->slave_name = NULL; + } +#endif mutex_unlock(&dma_list_mutex); } EXPORT_SYMBOL_GPL(dma_release_channel); @@ -1562,3 +1577,108 @@ static int __init dma_bus_init(void) return class_register(&dma_devclass); } arch_initcall(dma_bus_init); + +#ifdef CONFIG_DEBUG_FS +static void *dmaengine_seq_start(struct seq_file *s, loff_t *pos) +{ + struct dma_device *dma_dev = NULL; + loff_t index = *pos; + + s->private = ""; + + mutex_lock(&dma_list_mutex); + list_for_each_entry(dma_dev, &dma_device_list, global_node) + if (index-- == 0) { + mutex_unlock(&dma_list_mutex); + return dma_dev; + } + mutex_unlock(&dma_list_mutex); + + return NULL; +} + +static void *dmaengine_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct dma_device *dma_dev = v; + void *ret = NULL; + + mutex_lock(&dma_list_mutex); + if (list_is_last(&dma_dev->global_node, &dma_device_list)) + ret = NULL; + else + ret = list_entry(dma_dev->global_node.next, + struct dma_device, global_node); + mutex_unlock(&dma_list_mutex); + + s->private = "\n"; + ++*pos; + + return ret; +} + +static void dmaengine_seq_stop(struct seq_file *s, void *v) +{ +} + +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%d:", dma_dev->dev_id, + chan->chan_id); + if (chan->slave_name) + seq_printf(s, "\t\t%s\n", chan->slave_name); + else + seq_printf(s, "\t\t%s\n", "in-use"); + } + } +} + +static int dmaengine_seq_show(struct seq_file *s, void *v) +{ + struct dma_device *dma_dev = v; + + seq_printf(s, "%sdma%d (%s): number of channels: %u\n", + (char *)s->private, 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); + + return 0; +} + +static const struct seq_operations dmaengine_seq_ops = { + .start = dmaengine_seq_start, + .next = dmaengine_seq_next, + .stop = dmaengine_seq_stop, + .show = dmaengine_seq_show, +}; + +static int dmaengine_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &dmaengine_seq_ops); +} + +static const struct file_operations dmaengine_operations = { + .owner = THIS_MODULE, + .open = dmaengine_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __init dmaengine_debugfs_init(void) +{ + /* /sys/kernel/debug/dmaengine */ + debugfs_create_file("dmaengine", S_IFREG | 0444, NULL, NULL, + &dmaengine_operations); + return 0; +} +subsys_initcall(dmaengine_debugfs_init); + +#endif /* DEBUG_FS */ diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 64461fc64e1b..5b9d6b1aa6e9 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 + * @slave_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 *slave_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,