dma-buf: Add debugfs support (b89e3563) · Commits · 戴 / test

drivers/base/dma-buf.c

+158 −0

Original line number	Diff line number	Diff line
		@@ -27,9 +27,18 @@
		#include <linux/dma-buf.h>
		#include <linux/anon_inodes.h>
		#include <linux/export.h>
		#include <linux/debugfs.h>
		#include <linux/seq_file.h>

		static inline int is_dma_buf_file(struct file *);

		struct dma_buf_list {
		struct list_head head;
		struct mutex lock;
		};

		static struct dma_buf_list db_list;

		static int dma_buf_release(struct inode inode, struct file file)
		{
		struct dma_buf *dmabuf;
		@@ -42,6 +51,11 @@ static int dma_buf_release(struct inode inode, struct file file)
		BUG_ON(dmabuf->vmapping_counter);

		dmabuf->ops->release(dmabuf);

		mutex_lock(&db_list.lock);
		list_del(&dmabuf->list_node);
		mutex_unlock(&db_list.lock);

		kfree(dmabuf);
		return 0;
		}
		@@ -125,6 +139,10 @@ struct dma_buf dma_buf_export_named(void priv, const struct dma_buf_ops *ops,
		mutex_init(&dmabuf->lock);
		INIT_LIST_HEAD(&dmabuf->attachments);

		mutex_lock(&db_list.lock);
		list_add(&dmabuf->list_node, &db_list.head);
		mutex_unlock(&db_list.lock);

		return dmabuf;
		}
		EXPORT_SYMBOL_GPL(dma_buf_export_named);
		@@ -551,3 +569,143 @@ void dma_buf_vunmap(struct dma_buf dmabuf, void vaddr)
		mutex_unlock(&dmabuf->lock);
		}
		EXPORT_SYMBOL_GPL(dma_buf_vunmap);

		#ifdef CONFIG_DEBUG_FS
		static int dma_buf_describe(struct seq_file *s)
		{
		int ret;
		struct dma_buf *buf_obj;
		struct dma_buf_attachment *attach_obj;
		int count = 0, attach_count;
		size_t size = 0;

		ret = mutex_lock_interruptible(&db_list.lock);

		if (ret)
		return ret;

		seq_printf(s, "\nDma-buf Objects:\n");
		seq_printf(s, "\texp_name\tsize\tflags\tmode\tcount\n");

		list_for_each_entry(buf_obj, &db_list.head, list_node) {
		ret = mutex_lock_interruptible(&buf_obj->lock);

		if (ret) {
		seq_printf(s,
		"\tERROR locking buffer object: skipping\n");
		continue;
		}

		seq_printf(s, "\t");

		seq_printf(s, "\t%s\t%08zu\t%08x\t%08x\t%08ld\n",
		buf_obj->exp_name, buf_obj->size,
		buf_obj->file->f_flags, buf_obj->file->f_mode,
		(long)(buf_obj->file->f_count.counter));

		seq_printf(s, "\t\tAttached Devices:\n");
		attach_count = 0;

		list_for_each_entry(attach_obj, &buf_obj->attachments, node) {
		seq_printf(s, "\t\t");

		seq_printf(s, "%s\n", attach_obj->dev->init_name);
		attach_count++;
		}

		seq_printf(s, "\n\t\tTotal %d devices attached\n",
		attach_count);

		count++;
		size += buf_obj->size;
		mutex_unlock(&buf_obj->lock);
		}

		seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size);

		mutex_unlock(&db_list.lock);
		return 0;
		}

		static int dma_buf_show(struct seq_file s, void unused)
		{
		void (func)(struct seq_file ) = s->private;
		func(s);
		return 0;
		}

		static int dma_buf_debug_open(struct inode inode, struct file file)
		{
		return single_open(file, dma_buf_show, inode->i_private);
		}

		static const struct file_operations dma_buf_debug_fops = {
		.open = dma_buf_debug_open,
		.read = seq_read,
		.llseek = seq_lseek,
		.release = single_release,
		};

		static struct dentry *dma_buf_debugfs_dir;

		static int dma_buf_init_debugfs(void)
		{
		int err = 0;
		dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL);
		if (IS_ERR(dma_buf_debugfs_dir)) {
		err = PTR_ERR(dma_buf_debugfs_dir);
		dma_buf_debugfs_dir = NULL;
		return err;
		}

		err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe);

		if (err)
		pr_debug("dma_buf: debugfs: failed to create node bufinfo\n");

		return err;
		}

		static void dma_buf_uninit_debugfs(void)
		{
		if (dma_buf_debugfs_dir)
		debugfs_remove_recursive(dma_buf_debugfs_dir);
		}

		int dma_buf_debugfs_create_file(const char *name,
		int (write)(struct seq_file ))
		{
		struct dentry *d;

		d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir,
		write, &dma_buf_debug_fops);

		if (IS_ERR(d))
		return PTR_ERR(d);

		return 0;
		}
		#else
		static inline int dma_buf_init_debugfs(void)
		{
		return 0;
		}
		static inline void dma_buf_uninit_debugfs(void)
		{
		}
		#endif

		static int __init dma_buf_init(void)
		{
		mutex_init(&db_list.lock);
		INIT_LIST_HEAD(&db_list.head);
		dma_buf_init_debugfs();
		return 0;
		}
		subsys_initcall(dma_buf_init);

		static void __exit dma_buf_deinit(void)
		{
		dma_buf_uninit_debugfs();
		}
		__exitcall(dma_buf_deinit);

include/linux/dma-buf.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -113,6 +113,7 @@ struct dma_buf_ops {
		* @attachments: list of dma_buf_attachment that denotes all devices attached.
		* @ops: dma_buf_ops associated with this buffer object.
		* @exp_name: name of the exporter; useful for debugging.
		* @list_node: node for dma_buf accounting and debugging.
		* @priv: exporter specific private data for this buffer object.
		*/
		struct dma_buf {
		@@ -125,6 +126,7 @@ struct dma_buf {
		unsigned vmapping_counter;
		void *vmap_ptr;
		const char *exp_name;
		struct list_head list_node;
		void *priv;
		};

		@@ -192,5 +194,6 @@ int dma_buf_mmap(struct dma_buf , struct vm_area_struct ,
		unsigned long);
		void dma_buf_vmap(struct dma_buf );
		void dma_buf_vunmap(struct dma_buf , void vaddr);

		int dma_buf_debugfs_create_file(const char *name,
		int (write)(struct seq_file ));
		#endif /* __DMA_BUF_H__ */

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