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dmaengine: Create debug directories for DMA devices

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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: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200306142839.17910-4-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Peter Ujfalusi 2020-03-06 16:28:39 +02:00 committed by Vinod Koul
parent db8d9b4c9b
commit 26cf132de6
3 changed files with 44 additions and 1 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

28
drivers/dma/dmaengine.c
View file

@ -62,6 +62,22 @@ static long dmaengine_ref_count;
#ifdef CONFIG_DEBUG_FS #ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h> #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, static void dmaengine_dbg_summary_show(struct seq_file *s,
struct dma_device *dma_dev) struct dma_device *dma_dev)
{ {
@ -107,7 +123,7 @@ DEFINE_SHOW_ATTRIBUTE(dmaengine_summary);
static void __init dmaengine_debugfs_init(void) 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 */ /* /sys/kernel/debug/dmaengine/summary */
debugfs_create_file("summary", 0444, rootdir, NULL, debugfs_create_file("summary", 0444, rootdir, NULL,
@ -115,6 +131,12 @@ static void __init dmaengine_debugfs_init(void)
} }
#else #else
static inline void dmaengine_debugfs_init(void) { } 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 */ #endif /* DEBUG_FS */
/* --- sysfs implementation --- */ /* --- sysfs implementation --- */
@ -1265,6 +1287,8 @@ int dma_async_device_register(struct dma_device *device)
dma_channel_rebalance(); dma_channel_rebalance();
mutex_unlock(&dma_list_mutex); mutex_unlock(&dma_list_mutex);
dmaengine_debug_register(device);
return 0; return 0;
err_out: err_out:
@ -1298,6 +1322,8 @@ void dma_async_device_unregister(struct dma_device *device)
{ {
struct dma_chan *chan, *n; struct dma_chan *chan, *n;
dmaengine_debug_unregister(device);
list_for_each_entry_safe(chan, n, &device->channels, device_node) list_for_each_entry_safe(chan, n, &device->channels, device_node)
__dma_async_device_channel_unregister(device, chan); __dma_async_device_channel_unregister(device, chan);

16
drivers/dma/dmaengine.h
View file

@ -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_slave_channel(struct dma_chan *chan);
struct dma_chan *dma_get_any_slave_channel(struct dma_device *device); 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 #endif

1
include/linux/dmaengine.h
View file

@ -902,6 +902,7 @@ struct dma_device {
/* debugfs support */ /* debugfs support */
#ifdef CONFIG_DEBUG_FS #ifdef CONFIG_DEBUG_FS
void (*dbg_summary_show)(struct seq_file *s, struct dma_device *dev); void (*dbg_summary_show)(struct seq_file *s, struct dma_device *dev);
struct dentry *dbg_dev_root;
#endif #endif
}; };