[RFC PATCH net-next 5/5] net: ethernet: zte: zx279128s: debugfs knobs for the WLAN ring

[Agustin Santiago Isasmendi <isasmendi.agus@gmail.com>]

wlan_state (counters and port table), wlan_inject_all (inject every
frame of the bound interfaces, as the vendor firmware does, to exercise
the ring and the trap path without flows) and wlan_bind (bind an
interface by name).  Testing aids, kept apart so they can be dropped.

Assisted-by: LLM
Signed-off-by: Agustin Santiago Isasmendi <isasmendi.agus@gmail.com>
---
 drivers/net/ethernet/zte/zx279128s-wlan.c | 34 +++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/drivers/net/ethernet/zte/zx279128s-wlan.c b/drivers/net/ethernet/zte/zx279128s-wlan.c
index 6c6f6a36d34f..29970db47a41 100644
--- a/drivers/net/ethernet/zte/zx279128s-wlan.c
+++ b/drivers/net/ethernet/zte/zx279128s-wlan.c
@@ -18,6 +18,7 @@
 #include <linux/platform_device.h>
 #include <linux/seq_file.h>
 #include <linux/tcp.h>
+#include <linux/uaccess.h>
 #include <linux/udp.h>
 #include <net/arp.h>
 #include <net/cfg80211.h>
@@ -751,6 +752,38 @@ static int zx_wlan_state_show(struct seq_file *s, void *data)
 	return 0;
 }
 
+/* Bind an interface by name without waiting for a flow (testing) */
+static ssize_t zx_wlan_bind_write(struct file *file, const char __user *ubuf,
+				  size_t count, loff_t *ppos)
+{
+	struct zx_eth_adapter *adapter = file->private_data;
+	char name[IFNAMSIZ + 1];
+	struct net_device *vif;
+	int ret;
+
+	if (count == 0 || count > IFNAMSIZ)
+		return -EINVAL;
+	if (copy_from_user(name, ubuf, count))
+		return -EFAULT;
+	name[count] = 0;
+	strim(name);
+	vif = dev_get_by_name(dev_net(adapter->wlan->napi.dev), name);
+	if (!vif)
+		return -ENODEV;
+	mutex_lock(&adapter->ppe_lock);
+	ret = zx_wlan_is_ap(vif) ? zx_wlan_port_get(adapter->wlan, vif) : -EINVAL;
+	mutex_unlock(&adapter->ppe_lock);
+	dev_put(vif);
+	return ret < 0 ? ret : count;
+}
+
+static const struct file_operations zx_wlan_bind_fops = {
+	.owner	= THIS_MODULE,
+	.open	= simple_open,
+	.write	= zx_wlan_bind_write,
+	.llseek	= noop_llseek,
+};
+
 void zx_wlan_debugfs_init(struct zx_eth_adapter *adapter, struct dentry *dir)
 {
 	if (!adapter->wlan)
@@ -759,6 +792,7 @@ void zx_wlan_debugfs_init(struct zx_eth_adapter *adapter, struct dentry *dir)
 				    zx_wlan_state_show);
 	debugfs_create_bool("wlan_inject_all", 0600, dir,
 			    &adapter->wlan->inject_all);
+	debugfs_create_file("wlan_bind", 0200, dir, adapter, &zx_wlan_bind_fops);
 }
 
 /* ---- init / fini --------------------------------------------------- */
-- 
2.30.2