[PATCH net-next 3/8] netdevsim: add pause frame stats

[Jakub Kicinski]

Add minimal ethtool interface for testing ethtool pause stats.

Signed-off-by: Jakub Kicinski <k...@kernel.org>
---
 drivers/net/netdevsim/Makefile    |  2 +-
 drivers/net/netdevsim/ethtool.c   | 64 +++++++++++++++++++++++++++++++
 drivers/net/netdevsim/netdev.c    |  1 +
 drivers/net/netdevsim/netdevsim.h | 11 ++++++
 4 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 drivers/net/netdevsim/ethtool.c

diff --git a/drivers/net/netdevsim/Makefile b/drivers/net/netdevsim/Makefile
index 4dfb389dbfd8..ade086eed955 100644
--- a/drivers/net/netdevsim/Makefile
+++ b/drivers/net/netdevsim/Makefile
@@ -3,7 +3,7 @@
 obj-$(CONFIG_NETDEVSIM) += netdevsim.o
 
 netdevsim-objs := \
-       netdev.o dev.o fib.o bus.o health.o udp_tunnels.o
+       netdev.o dev.o ethtool.o fib.o bus.o health.o udp_tunnels.o
 
 ifeq ($(CONFIG_BPF_SYSCALL),y)
 netdevsim-objs += \
diff --git a/drivers/net/netdevsim/ethtool.c b/drivers/net/netdevsim/ethtool.c
new file mode 100644
index 000000000000..7c016edfbcee
--- /dev/null
+++ b/drivers/net/netdevsim/ethtool.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+
+#include <linux/debugfs.h>
+#include <linux/ethtool.h>
+#include <linux/random.h>
+
+#include "netdevsim.h"
+
+static void
+nsim_get_pause_stats(struct net_device *dev,
+                    struct ethtool_pause_stats *pause_stats)
+{
+       struct netdevsim *ns = netdev_priv(dev);
+
+       if (ns->ethtool.report_stats_rx)
+               pause_stats->rx_pause_frames = 1;
+       if (ns->ethtool.report_stats_tx)
+               pause_stats->tx_pause_frames = 2;
+}
+
+static void
+nsim_get_pauseparam(struct net_device *dev, struct ethtool_pauseparam *pause)
+{
+       struct netdevsim *ns = netdev_priv(dev);
+
+       pause->autoneg = 0; /* We don't support ksettings, so can't pretend */
+       pause->rx_pause = ns->ethtool.rx;
+       pause->tx_pause = ns->ethtool.tx;
+}
+
+static int
+nsim_set_pauseparam(struct net_device *dev, struct ethtool_pauseparam *pause)
+{
+       struct netdevsim *ns = netdev_priv(dev);
+
+       if (pause->autoneg)
+               return -EINVAL;
+
+       ns->ethtool.rx = pause->rx_pause;
+       ns->ethtool.tx = pause->tx_pause;
+       return 0;
+}
+
+const struct ethtool_ops nsim_ethtool_ops = {
+       .get_pause_stats        = nsim_get_pause_stats,
+       .get_pauseparam         = nsim_get_pauseparam,
+       .set_pauseparam         = nsim_set_pauseparam,
+};
+
+void nsim_ethtool_init(struct netdevsim *ns)
+{
+       struct dentry *ethtool, *dir;
+
+       ns->netdev->ethtool_ops = &nsim_ethtool_ops;
+
+       ethtool = debugfs_create_dir("ethtool", ns->nsim_dev->ddir);
+
+       dir = debugfs_create_dir("pause", ethtool);
+       debugfs_create_bool("report_stats_rx", 0600, dir,
+                           &ns->ethtool.report_stats_rx);
+       debugfs_create_bool("report_stats_tx", 0600, dir,
+                           &ns->ethtool.report_stats_tx);
+}
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index 97cfb015a50b..7178468302c8 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -301,6 +301,7 @@ nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port 
*nsim_dev_port)
        ns->nsim_bus_dev = nsim_dev->nsim_bus_dev;
        SET_NETDEV_DEV(dev, &ns->nsim_bus_dev->dev);
        dev->netdev_ops = &nsim_netdev_ops;
+       nsim_ethtool_init(ns);
 
        err = nsim_udp_tunnels_info_create(nsim_dev, dev);
        if (err)
diff --git a/drivers/net/netdevsim/netdevsim.h 
b/drivers/net/netdevsim/netdevsim.h
index 284f7092241d..0c86561e6d8d 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -50,6 +50,13 @@ struct nsim_ipsec {
        u32 ok;
 };
 
+struct nsim_ethtool {
+       bool rx;
+       bool tx;
+       bool report_stats_rx;
+       bool report_stats_tx;
+};
+
 struct netdevsim {
        struct net_device *netdev;
        struct nsim_dev *nsim_dev;
@@ -80,12 +87,16 @@ struct netdevsim {
                u32 ports[2][NSIM_UDP_TUNNEL_N_PORTS];
                struct debugfs_u32_array dfs_ports[2];
        } udp_ports;
+
+       struct nsim_ethtool ethtool;
 };
 
 struct netdevsim *
 nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port);
 void nsim_destroy(struct netdevsim *ns);
 
+void nsim_ethtool_init(struct netdevsim *ns);
+
 void nsim_udp_tunnels_debugfs_create(struct nsim_dev *nsim_dev);
 int nsim_udp_tunnels_info_create(struct nsim_dev *nsim_dev,
                                 struct net_device *dev);
-- 
2.26.2