net/mlx4_en: Add a service task

Add a service task to run tasks that needed to be executed periodically.
Currently the only task is a watchdog to catch NIC clock overflow, to make
timestamping accurate.
Will move the statistics task into this framework in a later patch.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 47 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/drivers/net/ethernet/mellanox/mlx4/en_clock.c
index 501c72f1fbeb..2f181219662e 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c
@@ -129,4 +129,23 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev)
 
         timecounter_init(&mdev->clock, &mdev->cycles,
                          ktime_to_ns(ktime_get_real()));
+
+        /* Calculate period in seconds to call the overflow watchdog - to make
+         * sure counter is checked at least once every wrap around.
+         */
+        mdev->overflow_period =
+                (cyclecounter_cyc2ns(&mdev->cycles,
+                                    mdev->cycles.mask) / NSEC_PER_SEC / 2)
+                * HZ;
+}
+
+void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev)
+{
+        bool timeout = time_is_before_jiffies(mdev->last_overflow_check +
+                                              mdev->overflow_period);
+
+        if (timeout) {
+                timecounter_read(&mdev->clock);
+                mdev->last_overflow_check = jiffies;
+        }
 }
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index 4cb9f3203973..f4f88b846020 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -1361,6 +1361,26 @@ static void mlx4_en_do_get_stats(struct work_struct *work)
         mutex_unlock(&mdev->state_lock);
 }
 
+/* mlx4_en_service_task - Run service task for tasks that needed to be done
+ * periodically
+ */
+static void mlx4_en_service_task(struct work_struct *work)
+{
+        struct delayed_work *delay = to_delayed_work(work);
+        struct mlx4_en_priv *priv = container_of(delay, struct mlx4_en_priv,
+                                                 service_task);
+        struct mlx4_en_dev *mdev = priv->mdev;
+
+        mutex_lock(&mdev->state_lock);
+        if (mdev->device_up) {
+                mlx4_en_ptp_overflow_check(mdev);
+
+                queue_delayed_work(mdev->workqueue, &priv->service_task,
+                                   SERVICE_TASK_DELAY);
+        }
+        mutex_unlock(&mdev->state_lock);
+}
+
 static void mlx4_en_linkstate(struct work_struct *work)
 {
         struct mlx4_en_priv *priv = container_of(work, struct mlx4_en_priv,
@@ -1865,6 +1885,7 @@ void mlx4_en_destroy_netdev(struct net_device *dev)
                 mlx4_free_hwq_res(mdev->dev, &priv->res, MLX4_EN_PAGE_SIZE);
 
         cancel_delayed_work(&priv->stats_task);
+        cancel_delayed_work(&priv->service_task);
         /* flush any pending task for this netdev */
         flush_workqueue(mdev->workqueue);
 
@@ -2084,6 +2105,7 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
         INIT_WORK(&priv->watchdog_task, mlx4_en_restart);
         INIT_WORK(&priv->linkstate_task, mlx4_en_linkstate);
         INIT_DELAYED_WORK(&priv->stats_task, mlx4_en_do_get_stats);
+        INIT_DELAYED_WORK(&priv->service_task, mlx4_en_service_task);
 #ifdef CONFIG_MLX4_EN_DCB
         if (!mlx4_is_slave(priv->mdev->dev)) {
                 if (mdev->dev->caps.flags & MLX4_DEV_CAP_FLAG_SET_ETH_SCHED) {
@@ -2206,6 +2228,8 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
         }
         mlx4_en_set_default_moderation(priv);
         queue_delayed_work(mdev->workqueue, &priv->stats_task, STATS_DELAY);
+        queue_delayed_work(mdev->workqueue, &priv->service_task,
+                           SERVICE_TASK_DELAY);
         return 0;
 
 out:
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 85b0754ec8ac..b1d7657b2bf5 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -78,6 +78,7 @@
 #define STAMP_SHIFT             31
 #define STAMP_VAL               0x7fffffff
 #define STATS_DELAY             (HZ / 4)
+#define SERVICE_TASK_DELAY      (HZ / 4)
 #define MAX_NUM_OF_FS_RULES     256
 
 #define MLX4_EN_FILTER_HASH_SHIFT 4
@@ -355,6 +356,7 @@ struct mlx4_en_dev {
         struct cyclecounter     cycles;
         struct timecounter      clock;
         unsigned long           last_overflow_check;
+        unsigned long           overflow_period;
 };
 
 
@@ -519,6 +521,7 @@ struct mlx4_en_priv {
         struct work_struct watchdog_task;
         struct work_struct linkstate_task;
         struct delayed_work stats_task;
+        struct delayed_work service_task;
         struct mlx4_en_perf_stats pstats;
         struct mlx4_en_pkt_stats pkstats;
         struct mlx4_en_port_stats port_stats;
@@ -645,6 +648,7 @@ void mlx4_en_cleanup_filters(struct mlx4_en_priv *priv,
 #define MLX4_EN_NUM_SELF_TEST   5
 void mlx4_en_ex_selftest(struct net_device *dev, u32 *flags, u64 *buf);
 u64 mlx4_en_mac_to_u64(u8 *addr);
+void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev);
 
 /*
  * Functions for time stamping