netdevsim: add debugfs-triggered queue reset

Support triggering queue reset via debugfs for an upcoming test.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index cfb079a345320ecc066a4f5f7c111a088041b089..d013b64985390e869a74e932a07f01061f3ff431 100644 (file)
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -20,6 +20,7 @@
 #include <linux/netdevice.h>
 #include <linux/slab.h>
 #include <net/netdev_queues.h>
+#include <net/netdev_rx_queue.h>
 #include <net/page_pool/helpers.h>
 #include <net/netlink.h>
 #include <net/net_shaper.h>
@@ -29,6 +30,8 @@
 
 #include "netdevsim.h"
 
+MODULE_IMPORT_NS("NETDEV_INTERNAL");
+
 #define NSIM_RING_SIZE         256
 
 static int nsim_napi_rx(struct nsim_rq *rq, struct sk_buff *skb)
@@ -722,6 +725,54 @@ static const struct netdev_queue_mgmt_ops nsim_queue_mgmt_ops = {
        .ndo_queue_stop         = nsim_queue_stop,
 };
 
+static ssize_t
+nsim_qreset_write(struct file *file, const char __user *data,
+                 size_t count, loff_t *ppos)
+{
+       struct netdevsim *ns = file->private_data;
+       unsigned int queue, mode;
+       char buf[32];
+       ssize_t ret;
+
+       if (count >= sizeof(buf))
+               return -EINVAL;
+       if (copy_from_user(buf, data, count))
+               return -EFAULT;
+       buf[count] = '\0';
+
+       ret = sscanf(buf, "%u %u", &queue, &mode);
+       if (ret != 2)
+               return -EINVAL;
+
+       rtnl_lock();
+       if (!netif_running(ns->netdev)) {
+               ret = -ENETDOWN;
+               goto exit_unlock;
+       }
+
+       if (queue >= ns->netdev->real_num_rx_queues) {
+               ret = -EINVAL;
+               goto exit_unlock;
+       }
+
+       ns->rq_reset_mode = mode;
+       ret = netdev_rx_queue_restart(ns->netdev, queue);
+       ns->rq_reset_mode = 0;
+       if (ret)
+               goto exit_unlock;
+
+       ret = count;
+exit_unlock:
+       rtnl_unlock();
+       return ret;
+}
+
+static const struct file_operations nsim_qreset_fops = {
+       .open = simple_open,
+       .write = nsim_qreset_write,
+       .owner = THIS_MODULE,
+};
+
 static ssize_t
 nsim_pp_hold_read(struct file *file, char __user *data,
                  size_t count, loff_t *ppos)
@@ -934,6 +985,9 @@ nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port)
 
        ns->pp_dfs = debugfs_create_file("pp_hold", 0600, nsim_dev_port->ddir,
                                         ns, &nsim_pp_hold_fops);
+       ns->qr_dfs = debugfs_create_file("queue_reset", 0200,
+                                        nsim_dev_port->ddir, ns,
+                                        &nsim_qreset_fops);
 
        return ns;
 
@@ -947,6 +1001,7 @@ void nsim_destroy(struct netdevsim *ns)
        struct net_device *dev = ns->netdev;
        struct netdevsim *peer;
 
+       debugfs_remove(ns->qr_dfs);
        debugfs_remove(ns->pp_dfs);
 
        rtnl_lock();

diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 8c50969b1240694af8c387bd109328bca8e475ea..a70f62af4c88612e94e471cbe2ab5f6f4125f851 100644 (file)
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -136,6 +136,7 @@ struct netdevsim {
 
        struct page *page;
        struct dentry *pp_dfs;
+       struct dentry *qr_dfs;
 
        struct nsim_ethtool ethtool;
        struct netdevsim __rcu *peer;