Re: [PATCH 2/3] accel/qaic: Add fifo size debugfs

[Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>]

Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>

On 11.03.2024 17:58, Jeffrey Hugo wrote:
> Each DMA Bridge Channel (dbc) has a unique configured fifo size which is
> specified by the userspace client of that dbc. Since the fifo is
> circular, it is useful to know the configured size when debugging
> issues.
> 
> Add a per-dbc subdirectory in debugfs and in each subdirectory add a
> fifo_size entry that will display the size of that dbc's fifo when read.
> 
> Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
> Reviewed-by: Carl Vanderlip <quic_carlv@quicinc.com>
> Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
> ---
>  drivers/accel/qaic/qaic_debugfs.c | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/drivers/accel/qaic/qaic_debugfs.c b/drivers/accel/qaic/qaic_debugfs.c
> index 4f87fe29be1a..9d56cd451b64 100644
> --- a/drivers/accel/qaic/qaic_debugfs.c
> +++ b/drivers/accel/qaic/qaic_debugfs.c
> @@ -11,6 +11,7 @@
>  #include <linux/mutex.h>
>  #include <linux/pci.h>
>  #include <linux/seq_file.h>
> +#include <linux/sprintf.h>
>  #include <linux/string.h>
>  #include <linux/types.h>
>  #include <linux/workqueue.h>
> @@ -20,6 +21,7 @@
>  
>  #define BOOTLOG_POOL_SIZE		16
>  #define BOOTLOG_MSG_SIZE		512
> +#define QAIC_DBC_DIR_NAME		9
>  
>  struct bootlog_msg {
>  	/* Buffer for bootlog messages */
> @@ -74,14 +76,43 @@ static const struct file_operations bootlog_fops = {
>  	.release = single_release,
>  };
>  
> +static int read_dbc_fifo_size(struct seq_file *s, void *unused)
> +{
> +	struct dma_bridge_chan *dbc = s->private;
> +
> +	seq_printf(s, "%u\n", dbc->nelem);
> +	return 0;
> +}
> +
> +static int fifo_size_open(struct inode *inode, struct file *file)
> +{
> +	return single_open(file, read_dbc_fifo_size, inode->i_private);
> +}
> +
> +static const struct file_operations fifo_size_fops = {
> +	.owner = THIS_MODULE,
> +	.open = fifo_size_open,
> +	.read = seq_read,
> +	.llseek = seq_lseek,
> +	.release = single_release,
> +};
> +
>  void qaic_debugfs_init(struct qaic_drm_device *qddev)
>  {
>  	struct qaic_device *qdev = qddev->qdev;
>  	struct dentry *debugfs_root;
> +	struct dentry *debugfs_dir;
> +	char name[QAIC_DBC_DIR_NAME];
> +	u32 i;
>  
>  	debugfs_root = to_drm(qddev)->debugfs_root;
>  
>  	debugfs_create_file("bootlog", 0400, debugfs_root, qdev, &bootlog_fops);
> +	for (i = 0; i < qdev->num_dbc; ++i) {
> +		snprintf(name, QAIC_DBC_DIR_NAME, "dbc%03u", i);
> +		debugfs_dir = debugfs_create_dir(name, debugfs_root);
> +		debugfs_create_file("fifo_size", 0400, debugfs_dir, &qdev->dbc[i], &fifo_size_fops);
> +	}
>  }
>  
>  static struct bootlog_page *alloc_bootlog_page(struct qaic_device *qdev)