ionic: add a watchdog timer to monitor heartbeat

Add a watchdog to periodically monitor the NIC heartbeat.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/pensando/ionic/ionic.h

@@ -46,6 +46,8 @@ struct ionic {
 	DECLARE_BITMAP(intrs, IONIC_INTR_CTRL_REGS_MAX);
 	struct work_struct nb_work;
 	struct notifier_block nb;
+	struct timer_list watchdog_timer;
+	int watchdog_period;
 };
 
 struct ionic_admin_ctx {

drivers/net/ethernet/pensando/ionic/ionic_dev.c

@@ -11,6 +11,16 @@
 #include "ionic_dev.h"
 #include "ionic_lif.h"
 
+static void ionic_watchdog_cb(struct timer_list *t)
+{
+	struct ionic *ionic = from_timer(ionic, t, watchdog_timer);
+
+	mod_timer(&ionic->watchdog_timer,
+		  round_jiffies(jiffies + ionic->watchdog_period));
+
+	ionic_heartbeat_check(ionic);
+}
+
 void ionic_init_devinfo(struct ionic *ionic)
 {
 	struct ionic_dev *idev = &ionic->idev;
@@ -72,6 +82,11 @@ int ionic_dev_setup(struct ionic *ionic)
 		return -EFAULT;
 	}
 
+	timer_setup(&ionic->watchdog_timer, ionic_watchdog_cb, 0);
+	ionic->watchdog_period = IONIC_WATCHDOG_SECS * HZ;
+	mod_timer(&ionic->watchdog_timer,
+		  round_jiffies(jiffies + ionic->watchdog_period));
+
 	idev->db_pages = bar->vaddr;
 	idev->phy_db_pages = bar->bus_addr;
 
@@ -80,7 +95,7 @@ int ionic_dev_setup(struct ionic *ionic)
 
 void ionic_dev_teardown(struct ionic *ionic)
 {
-	/* place holder */
+	del_timer_sync(&ionic->watchdog_timer);
 }
 
 /* Devcmd Interface */
@@ -93,7 +108,7 @@ int ionic_heartbeat_check(struct ionic *ionic)
 
 	/* wait a little more than one second before testing again */
 	hb_time = jiffies;
-	if (time_before(hb_time, (idev->last_hb_time + (HZ * 2))))
+	if (time_before(hb_time, (idev->last_hb_time + ionic->watchdog_period)))
 		return 0;
 
 	/* firmware is useful only if fw_status is non-zero */

drivers/net/ethernet/pensando/ionic/ionic_dev.h

@@ -16,6 +16,7 @@
 #define IONIC_MIN_TXRX_DESC		16
 #define IONIC_DEF_TXRX_DESC		4096
 #define IONIC_LIFS_MAX			1024
+#define IONIC_WATCHDOG_SECS		5
 #define IONIC_ITR_COAL_USEC_DEFAULT	64
 
 #define IONIC_DEV_CMD_REG_VERSION	1