Commit 26cf132d authored by Peter Ujfalusi's avatar Peter Ujfalusi Committed by Vinod Koul
Browse files

dmaengine: Create debug directories for DMA devices 



Create a placeholder directory for each registered DMA device.

DMA drivers can use the dmaengine_get_debugfs_root() call to get their
debugfs root and can populate with custom files to aim debugging.

Signed-off-by: default avatarPeter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200306142839.17910-4-peter.ujfalusi@ti.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent db8d9b4c

drivers/dma/dmaengine.c

+27 −1
Original line number Diff line number Diff line
@@ -62,6 +62,22 @@ static long dmaengine_ref_count; 
#ifdef CONFIG_DEBUG_FS

#include <linux/debugfs.h>



static struct dentry *rootdir;



static void dmaengine_debug_register(struct dma_device *dma_dev)

{

	dma_dev->dbg_dev_root = debugfs_create_dir(dev_name(dma_dev->dev),

						   rootdir);

	if (IS_ERR(dma_dev->dbg_dev_root))

		dma_dev->dbg_dev_root = NULL;

}



static void dmaengine_debug_unregister(struct dma_device *dma_dev)

{

	debugfs_remove_recursive(dma_dev->dbg_dev_root);

	dma_dev->dbg_dev_root = NULL;

}



static void dmaengine_dbg_summary_show(struct seq_file *s,

				       struct dma_device *dma_dev)

{
@@ -107,7 +123,7 @@ DEFINE_SHOW_ATTRIBUTE(dmaengine_summary); 


static void __init dmaengine_debugfs_init(void)

{

	struct dentry *rootdir = debugfs_create_dir("dmaengine", NULL);

	rootdir = debugfs_create_dir("dmaengine", NULL);



	/* /sys/kernel/debug/dmaengine/summary */

	debugfs_create_file("summary", 0444, rootdir, NULL,
@@ -115,6 +131,12 @@ static void __init dmaengine_debugfs_init(void) 
}

#else

static inline void dmaengine_debugfs_init(void) { }

static inline int dmaengine_debug_register(struct dma_device *dma_dev)

{

	return 0;

}



static inline void dmaengine_debug_unregister(struct dma_device *dma_dev) { }

#endif	/* DEBUG_FS */



/* --- sysfs implementation --- */
@@ -1265,6 +1287,8 @@ int dma_async_device_register(struct dma_device *device) 
	dma_channel_rebalance();

	mutex_unlock(&dma_list_mutex);



	dmaengine_debug_register(device);



	return 0;



err_out:
@@ -1298,6 +1322,8 @@ void dma_async_device_unregister(struct dma_device *device) 
{

	struct dma_chan *chan, *n;



	dmaengine_debug_unregister(device);



	list_for_each_entry_safe(chan, n, &device->channels, device_node)

		__dma_async_device_channel_unregister(device, chan);

drivers/dma/dmaengine.h

+16 −0
Original line number Diff line number Diff line
@@ -182,4 +182,20 @@ 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 <linux/debugfs.h>



static inline struct dentry *

dmaengine_get_debugfs_root(struct dma_device *dma_dev) {

	return dma_dev->dbg_dev_root;

}

#else

struct dentry;

static inline struct dentry *

dmaengine_get_debugfs_root(struct dma_device *dma_dev)

{

	return NULL;

}

#endif /* CONFIG_DEBUG_FS */



#endif

include/linux/dmaengine.h

+1 −0
Original line number Diff line number Diff line
@@ -902,6 +902,7 @@ struct dma_device { 
	/* debugfs support */

#ifdef CONFIG_DEBUG_FS

	void (*dbg_summary_show)(struct seq_file *s, struct dma_device *dev);

	struct dentry *dbg_dev_root;

#endif

};

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