RE: [PATCH v3 08/10] ntb_pingpong: Add a debugfs file to get the ping count

["Allen Hubbe" <Allen.Hubbe@emc.com>]

From: Logan Gunthorpe
> This commit adds a debugfs 'count' file to ntb_pingpong. This is so
> testing with ntb_pingpong can be automated beyond just checking the
> logs for pong messages.
> 
> The count file returns a number which increments every pong. The
> counter can be cleared by writing a zero.
> 
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>

Acked-by: Allen Hubbe <Allen.Hubbe@emc.com>

> ---
>  drivers/ntb/test/ntb_pingpong.c | 62 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 61 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ntb/test/ntb_pingpong.c b/drivers/ntb/test/ntb_pingpong.c
> index fe16005..7d31179 100644
> --- a/drivers/ntb/test/ntb_pingpong.c
> +++ b/drivers/ntb/test/ntb_pingpong.c
> @@ -61,6 +61,7 @@
>  #include <linux/pci.h>
>  #include <linux/slab.h>
>  #include <linux/spinlock.h>
> +#include <linux/debugfs.h>
> 
>  #include <linux/ntb.h>
> 
> @@ -96,8 +97,13 @@ struct pp_ctx {
>  	spinlock_t			db_lock;
>  	struct timer_list		db_timer;
>  	unsigned long			db_delay;
> +	struct dentry			*debugfs_node_dir;
> +	struct dentry			*debugfs_count;
> +	atomic_t			count;
>  };
> 
> +static struct dentry *pp_debugfs_dir;
> +
>  static void pp_ping(unsigned long ctx)
>  {
>  	struct pp_ctx *pp = (void *)ctx;
> @@ -171,10 +177,32 @@ static void pp_db_event(void *ctx, int vec)
>  		dev_dbg(&pp->ntb->dev,
>  			"Pong vec %d bits %#llx\n",
>  			vec, db_bits);
> +		atomic_inc(&pp->count);
>  	}
>  	spin_unlock_irqrestore(&pp->db_lock, irqflags);
>  }
> 
> +static int pp_debugfs_setup(struct pp_ctx *pp)
> +{
> +	struct pci_dev *pdev = pp->ntb->pdev;
> +
> +	if (!pp_debugfs_dir)
> +		return -ENODEV;
> +
> +	pp->debugfs_node_dir = debugfs_create_dir(pci_name(pdev),
> +						  pp_debugfs_dir);
> +	if (!pp->debugfs_node_dir)
> +		return -ENODEV;
> +
> +	pp->debugfs_count = debugfs_create_atomic_t("count", S_IRUSR | S_IWUSR,
> +						    pp->debugfs_node_dir,
> +						    &pp->count);
> +	if (!pp->debugfs_count)
> +		return -ENODEV;
> +
> +	return 0;
> +}
> +
>  static const struct ntb_ctx_ops pp_ops = {
>  	.link_event = pp_link_event,
>  	.db_event = pp_db_event,
> @@ -210,6 +238,7 @@ static int pp_probe(struct ntb_client *client,
> 
>  	pp->ntb = ntb;
>  	pp->db_bits = 0;
> +	atomic_set(&pp->count, 0);
>  	spin_lock_init(&pp->db_lock);
>  	setup_timer(&pp->db_timer, pp_ping, (unsigned long)pp);
>  	pp->db_delay = msecs_to_jiffies(delay_ms);
> @@ -218,6 +247,10 @@ static int pp_probe(struct ntb_client *client,
>  	if (rc)
>  		goto err_ctx;
> 
> +	rc = pp_debugfs_setup(pp);
> +	if (rc)
> +		goto err_ctx;
> +
>  	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
>  	ntb_link_event(ntb);
> 
> @@ -234,6 +267,8 @@ static void pp_remove(struct ntb_client *client,
>  {
>  	struct pp_ctx *pp = ntb->ctx;
> 
> +	debugfs_remove_recursive(pp->debugfs_node_dir);
> +
>  	ntb_clear_ctx(ntb);
>  	del_timer_sync(&pp->db_timer);
>  	ntb_link_disable(ntb);
> @@ -247,4 +282,29 @@ static struct ntb_client pp_client = {
>  		.remove = pp_remove,
>  	},
>  };
> -module_ntb_client(pp_client);
> +
> +static int __init pp_init(void)
> +{
> +	int rc;
> +
> +	if (debugfs_initialized())
> +		pp_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
> +
> +	rc = ntb_register_client(&pp_client);
> +	if (rc)
> +		goto err_client;
> +
> +	return 0;
> +
> +err_client:
> +	debugfs_remove_recursive(pp_debugfs_dir);
> +	return rc;
> +}
> +module_init(pp_init);
> +
> +static void __exit pp_exit(void)
> +{
> +	ntb_unregister_client(&pp_client);
> +	debugfs_remove_recursive(pp_debugfs_dir);
> +}
> +module_exit(pp_exit);
> --
> 2.1.4