On Fri, Dec 14, 2012 at 10:36 AM, wrote:
> From: Sumit Semwal
>
> Add debugfs support to make it easier to print debug information
> about the dma-buf buffers.
>
> Signed-off-by: Sumit Semwal
Looks line, only nitpick is that we have no idea who exported a given
buffer. So what about adding a new dma_buf_export_named which takes a
char * to identify the exporter, and then add a bit of cpp magic like
this:
#define dma_buf_export(args) dma_buf_export_named(args, stringify(__FILE))
At least for drm drivers using the prime helpers this should add the
file of the exporting driver, so would be good enough to identify the
exporter. Or we could add a dma_buf_export_dev which has a struct
device * as additional argument ... Otoh that wouldn't really work for
exporting dma_bufs from ION, so maybe a const char * is better.
-Daniel
> ---
> drivers/base/dma-buf.c | 149
> +++
> include/linux/dma-buf.h |6 +-
> 2 files changed, 154 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
> index a3f79c4..49fcf0f 100644
> --- a/drivers/base/dma-buf.c
> +++ b/drivers/base/dma-buf.c
> @@ -27,9 +27,18 @@
> #include
> #include
> #include
> +#include
> +#include
>
> 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;
> @@ -40,6 +49,11 @@ static int dma_buf_release(struct inode *inode, struct
> file *file)
> dmabuf = file->private_data;
>
> dmabuf->ops->release(dmabuf);
> +
> + mutex_lock(&db_list.lock);
> + list_del(&dmabuf->list_node);
> + mutex_unlock(&db_list.lock);
> +
> kfree(dmabuf);
> return 0;
> }
> @@ -120,6 +134,10 @@ struct dma_buf *dma_buf_export(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);
> @@ -505,3 +523,134 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
> dmabuf->ops->vunmap(dmabuf, vaddr);
> }
> EXPORT_SYMBOL_GPL(dma_buf_vunmap);
> +
> +static int dma_buf_init_debugfs(void);
> +static void dma_buf_uninit_debugfs(void);
> +
> +static void __init dma_buf_init(void)
> +{
> + mutex_init(&db_list.lock);
> + INIT_LIST_HEAD(&db_list.head);
> + dma_buf_init_debugfs();
> +}
> +
> +static void __exit dma_buf_deinit(void)
> +{
> + dma_buf_uninit_debugfs();
> +}
> +
> +#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, "\tsize\tflags\tmode\tcount\n");
> +
> + list_for_each_entry(buf_obj, &db_list.head, list_node) {
> + seq_printf(s, "\t");
> +
> + seq_printf(s, "%08zu\t%08x\t%08x\t%08d\n",
> + buf_obj->size, buf_obj->file->f_flags,
> + buf_obj->file->f_mode,
> + 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;
> + }
> +
> + 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 stru
