Commit b89e3563 authored by Sumit Semwal's avatar Sumit Semwal

dma-buf: Add debugfs support

Add debugfs support to make it easier to print debug information
about the dma-buf buffers.

Cc: Dave Airlie <airlied@redhat.com>
 [minor fixes on init and warning fix]
Cc: Dan Carpenter <dan.carpenter@oracle.com>
 [remove double unlock in fail case]
Signed-off-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
parent 78df9695
......@@ -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);
......@@ -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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