dpa_eth: add FSL_DPAA_DBG_LOOP debug option

Add debug option to divert traffic received on one DPAA interface
directly to another DPAA interface. By default this option is disabled.
When enabled special debugfs entries appear for each DPAA interface
that allow changing the divert state from disabled (-1) to enabled by
writing the Tx interface number in them.

Signed-off-by: Madalin Bucur <madalin.bucur@freescale.com>
Change-Id: I7c92d074980dadef55077e43616cb3caa2787838
Reviewed-on: http://git.am.freescale.net:8181/13043
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Cristian-Constantin Sovaiala <Cristian.Sovaiala@freescale.com>
Reviewed-by: Jose Rivera <German.Rivera@freescale.com>

1 files changed, 106 insertions, 0 deletions

diff --git a/drivers/net/ethernet/freescale/dpa/dpaa_debugfs.c b/drivers/net/ethernet/freescale/dpa/dpaa_debugfs.c
index 0c884a5..a5665ac 100644
--- a/drivers/net/ethernet/freescale/dpa/dpaa_debugfs.c
+++ b/drivers/net/ethernet/freescale/dpa/dpaa_debugfs.c
@@ -41,6 +41,12 @@
 
 static int __cold dpa_debugfs_open(struct inode *inode, struct file *file);
 
+#ifdef CONFIG_FSL_DPAA_DBG_LOOP
+static int __cold dpa_debugfs_loop_open(struct inode *inode, struct file *file);
+static ssize_t dpa_loop_write(struct file *f,
+	const char __user *buf, size_t count, loff_t *off);
+#endif
+
 static struct dentry *dpa_debugfs_root;
 static const struct file_operations dpa_debugfs_fops = {
 	.open		= dpa_debugfs_open,
@@ -49,6 +55,16 @@ static const struct file_operations dpa_debugfs_fops = {
 	.release	= single_release,
 };
 
+#ifdef CONFIG_FSL_DPAA_DBG_LOOP
+static const struct file_operations dpa_debugfs_lp_fops = {
+	.open		= dpa_debugfs_loop_open,
+	.write		= dpa_loop_write,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+#endif
+
 static int dpa_debugfs_show(struct seq_file *file, void *offset)
 {
 	int				 i;
@@ -200,6 +216,74 @@ static int dpa_debugfs_show(struct seq_file *file, void *offset)
 	return 0;
 }
 
+#ifdef CONFIG_FSL_DPAA_DBG_LOOP
+static int dpa_debugfs_loop_show(struct seq_file *file, void *offset)
+{
+	struct dpa_priv_s *priv;
+
+	BUG_ON(offset == NULL);
+
+	priv = netdev_priv((struct net_device *)file->private);
+	seq_printf(file, "%d->%d\n", priv->loop_id, priv->loop_to);
+
+	return 0;
+}
+
+static int user_input_convert(const char __user *user_buf, size_t count,
+			      long *val)
+{
+	char buf[12];
+
+	if (count > sizeof(buf) - 1)
+		return -EINVAL;
+	if (copy_from_user(buf, user_buf, count))
+		return -EFAULT;
+	buf[count] = '\0';
+	if (kstrtol(buf, 0, val))
+		return -EINVAL;
+	return 0;
+}
+
+static ssize_t dpa_loop_write(struct file *f,
+	const char __user *buf, size_t count, loff_t *off)
+{
+	struct dpa_priv_s *priv;
+	struct net_device *netdev;
+	struct seq_file *sf;
+	int ret;
+	long val;
+
+	ret = user_input_convert(buf, count, &val);
+	if (ret)
+		return ret;
+
+	sf = (struct seq_file *)f->private_data;
+	netdev = (struct net_device *)sf->private;
+	priv = netdev_priv(netdev);
+
+	priv->loop_to = ((val < 0) || (val > 20)) ? -1 : val;
+
+	return count;
+}
+
+static int __cold dpa_debugfs_loop_open(struct inode *inode, struct file *file)
+{
+	int			 _errno;
+	const struct net_device	*net_dev;
+
+	_errno = single_open(file, dpa_debugfs_loop_show, inode->i_private);
+	if (unlikely(_errno < 0)) {
+		net_dev = (struct net_device *)inode->i_private;
+
+		if (netif_msg_drv((struct dpa_priv_s *)netdev_priv(net_dev)))
+			netdev_err(net_dev, "single_open() = %d\n",
+					_errno);
+	}
+
+	return _errno;
+}
+#endif /* CONFIG_FSL_DPAA_DBG_LOOP */
+
 static int __cold dpa_debugfs_open(struct inode *inode, struct file *file)
 {
 	int			 _errno;
@@ -219,6 +303,9 @@ static int __cold dpa_debugfs_open(struct inode *inode, struct file *file)
 int dpa_netdev_debugfs_create(struct net_device *net_dev)
 {
 	struct dpa_priv_s *priv = netdev_priv(net_dev);
+#ifdef CONFIG_FSL_DPAA_DBG_LOOP
+	char loop_file_name[100];
+#endif
 
 	if (unlikely(dpa_debugfs_root == NULL)) {
 		pr_err(KBUILD_MODNAME ": %s:%hu:%s(): \t%s\n",
@@ -241,6 +328,22 @@ int dpa_netdev_debugfs_create(struct net_device *net_dev)
 		return -ENOMEM;
 	}
 
+#ifdef CONFIG_FSL_DPAA_DBG_LOOP
+	sprintf(loop_file_name, "%s_loop", net_dev->name);
+	priv->debugfs_loop_file = debugfs_create_file(loop_file_name,
+							 S_IRUGO,
+							 dpa_debugfs_root,
+							 net_dev,
+							 &dpa_debugfs_lp_fops);
+	if (unlikely(priv->debugfs_loop_file == NULL)) {
+		netdev_err(net_dev, "debugfs_create_file(%s/%s/%s)",
+				powerpc_debugfs_root->d_iname,
+				dpa_debugfs_root->d_iname,
+				loop_file_name);
+
+		return -ENOMEM;
+	}
+#endif
 	return 0;
 }
 
@@ -249,6 +352,9 @@ void dpa_netdev_debugfs_remove(struct net_device *net_dev)
 	struct dpa_priv_s *priv = netdev_priv(net_dev);
 
 	debugfs_remove(priv->debugfs_file);
+#ifdef CONFIG_FSL_DPAA_DBG_LOOP
+	debugfs_remove(priv->debugfs_loop_file);
+#endif
 }
 
 static int __init dpa_debugfs_module_init(void)