Re: [RFC PATCH 1/3] drm/debugfs: create debugfs files during drm_dev_register().
From: Wambui Karuga
Date: Wed May 13 2020 - 14:12:39 EST
On Wed, 13 May 2020, Thomas Zimmermann wrote:
Hi
Am 13.05.20 um 13:41 schrieb Wambui Karuga:
Introduce the ability to track requests for the addition of drm debugfs
files at any time and have them added all at once during
drm_dev_register().
Drivers can add drm debugfs file requests to a new list tied to drm_device.
During drm_dev_register(), the new function drm_debugfs_create_file()
will iterate over the list of added files on a given minor to create
them.
Two new structs are introduced in this change: struct drm_simple_info
which represents a drm debugfs file entry and struct
drm_simple_info_entry which is used to track file requests and is the
main parameter of choice passed by functions. Each drm_simple_info_entry is
added to the new struct drm_device->debugfs_list for file requests.
Signed-off-by: Wambui Karuga <wambui.karugax@xxxxxxxxx>
---
drivers/gpu/drm/drm_debugfs.c | 59 ++++++++++++++++++++++++++++++++---
drivers/gpu/drm/drm_drv.c | 2 ++
include/drm/drm_debugfs.h | 38 ++++++++++++++++++++++
include/drm/drm_device.h | 12 +++++++
4 files changed, 107 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index 2bea22130703..03b0588ede68 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -145,9 +145,10 @@ static const struct drm_info_list drm_debugfs_list[] = {
static int drm_debugfs_open(struct inode *inode, struct file *file)
{
- struct drm_info_node *node = inode->i_private;
+ struct drm_simple_info_entry *entry = inode->i_private;
+ struct drm_simple_info *node = &entry->file;
- return single_open(file, node->info_ent->show, node);
+ return single_open(file, node->show_fn, entry);
}
@@ -159,6 +160,25 @@ static const struct file_operations drm_debugfs_fops = {
.release = single_release,
};
+/**
+ * drm_debugfs_create_file - create DRM debugfs file.
+ * @dev: drm_device that the file belongs to
+ *
+ * Create a DRM debugfs file from the list of files to be created
+ * from dev->debugfs_list.
+ */
+static void drm_debugfs_create_file(struct drm_minor *minor)
This function creates several files. I'd rather call it
drm_debugfs_create_added_files().
Okay, that makes sense. I can change that.
+{
+ struct drm_device *dev = minor->dev;
+ struct drm_simple_info_entry *entry;
+
+ list_for_each_entry(entry, &dev->debugfs_list, list) {
+ debugfs_create_file(entry->file.name,
+ S_IFREG | S_IRUGO, minor->debugfs_root,
+ entry,
+ &drm_debugfs_fops);
+ }
I think the created items should be removed from the list. That way,
drivers can call the function multiple times without recreating the same
files again.
Hadn't thought of that - I can try add that.
+}
/**
* drm_debugfs_create_files - Initialize a given set of debugfs files for DRM
@@ -213,8 +233,7 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
sprintf(name, "%d", minor_id);
minor->debugfs_root = debugfs_create_dir(name, root);
- drm_debugfs_create_files(drm_debugfs_list, DRM_DEBUGFS_ENTRIES,
- minor->debugfs_root, minor);
By removing these two lines, aren't you losing the files listed in
DRM_DEBUGFS_ENTRIES?
Yes.
When using the new functions, drm_debugfs_create_files() should not
be called at this point, but for compatibility these two lines should
be put back, I think.
+ drm_debugfs_create_file(minor);
if (drm_drv_uses_atomic_modeset(dev)) {
drm_atomic_debugfs_init(minor);
@@ -449,4 +468,36 @@ void drm_debugfs_crtc_remove(struct drm_crtc *crtc)
crtc->debugfs_entry = NULL;
}
+void drm_debugfs_add_file(struct drm_device *dev, const char *name,
+ drm_simple_show_t show_fn, void *data)
+{
+ struct drm_simple_info_entry *entry =
+ kzalloc(sizeof(*entry), GFP_KERNEL);
+
+ if (!entry)
+ return;
+
+ entry->file.name = name;
+ entry->file.show_fn = show_fn;
+ entry->file.data = data;
+ entry->dev = dev;
+
+ mutex_lock(&dev->debugfs_mutex);
+ list_add(&entry->list, &dev->debugfs_list);
+ mutex_unlock(&dev->debugfs_mutex);
+}
+EXPORT_SYMBOL(drm_debugfs_add_file);
+
+void drm_debugfs_add_files(struct drm_device *dev,
+ const struct drm_simple_info *files, int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ drm_debugfs_add_file(dev, files[i].name, files[i].show_fn,
+ files[i].data);
+ }
+}
+EXPORT_SYMBOL(drm_debugfs_add_files);
+
#endif /* CONFIG_DEBUG_FS */
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index bc38322f306e..c68df4e31aa0 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -646,12 +646,14 @@ int drm_dev_init(struct drm_device *dev,
INIT_LIST_HEAD(&dev->filelist_internal);
INIT_LIST_HEAD(&dev->clientlist);
INIT_LIST_HEAD(&dev->vblank_event_list);
+ INIT_LIST_HEAD(&dev->debugfs_list);
spin_lock_init(&dev->event_lock);
mutex_init(&dev->struct_mutex);
mutex_init(&dev->filelist_mutex);
mutex_init(&dev->clientlist_mutex);
mutex_init(&dev->master_mutex);
+ mutex_init(&dev->debugfs_mutex);
ret = drmm_add_action(dev, drm_dev_init_release, NULL);
if (ret)
diff --git a/include/drm/drm_debugfs.h b/include/drm/drm_debugfs.h
index 2188dc83957f..bbce580c3b38 100644
--- a/include/drm/drm_debugfs.h
+++ b/include/drm/drm_debugfs.h
@@ -34,6 +34,44 @@
#include <linux/types.h>
#include <linux/seq_file.h>
+
+struct drm_device;
+
+typedef int (*drm_simple_show_t)(struct seq_file *, void *);
+
+/**
+ * struct drm_simple_info - debugfs file entry
+ *
+ * This struct represents a debugfs file to be created.
+ */
+struct drm_simple_info {
drm_simple_info and drm_simple_info_entry seem to be misnomers. They
should probably have some reference to debugfs in their name.
I'll change the names.
Thanks,
wambui karuga
Best regards
Thomas
+ const char *name;
+ drm_simple_show_t show_fn;
+ u32 driver_features;
+ void *data;
+};
+
+/**
+ * struct drm_simple_info_entry - debugfs list entry
+ *
+ * This struct is used in tracking requests for new debugfs files
+ * to be created.
+ */
+struct drm_simple_info_entry {
+ struct drm_device *dev;
+ struct drm_simple_info file;
+ struct list_head list;
+};
+
+void drm_debugfs_add_file(struct drm_device *dev,
+ const char *name,
+ drm_simple_show_t show_fn,
+ void *data);
+
+void drm_debugfs_add_files(struct drm_device *dev,
+ const struct drm_simple_info *files,
+ int count);
+
/**
* struct drm_info_list - debugfs info list entry
*
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index a55874db9dd4..b84dfdac27b7 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -326,6 +326,18 @@ struct drm_device {
*/
struct drm_fb_helper *fb_helper;
+ /**
+ * @debugfs_mutex:
+ * Protects debugfs_list access.
+ */
+ struct mutex debugfs_mutex;
+
+ /** @debugfs_list:
+ * List of debugfs files to add.
+ * Files are added during drm_dev_register().
+ */
+ struct list_head debugfs_list;
+
/* Everything below here is for legacy driver, never use! */
/* private: */
#if IS_ENABLED(CONFIG_DRM_LEGACY)
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 NÃrnberg, Germany
(HRB 36809, AG NÃrnberg)
GeschÃftsfÃhrer: Felix ImendÃrffer