liquidio: CN23XX health monitoring

Adds support for watchdog based health monitoring
of octeon cores on cn23xx device.

Signed-off-by: Derek Chickles <derek.chickles@caviumnetworks.com>
Signed-off-by: Satanand Burla <satananda.burla@caviumnetworks.com>
Signed-off-by: Felix Manlunas <felix.manlunas@caviumnetworks.com>
Signed-off-by: Raghu Vatsavayi <raghu.vatsavayi@caviumnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cavium/liquidio/lio_main.c

@@ -24,6 +24,7 @@
 #include <linux/firmware.h>
 #include <linux/ptp_clock_kernel.h>
 #include <net/vxlan.h>
+#include <linux/kthread.h>
 #include "liquidio_common.h"
 #include "octeon_droq.h"
 #include "octeon_iq.h"
@@ -948,8 +949,6 @@ static void update_txq_status(struct octeon_device *oct, int iq_num)
 	struct lio *lio;
 	struct octeon_instr_queue *iq = oct->instr_queue[iq_num];
 
-	/*octeon_update_iq_read_idx(oct, iq);*/
-
 	netdev = oct->props[iq->ifidx].netdev;
 
 	/* This is needed because the first IQ does not have
@@ -1187,6 +1186,102 @@ static int octeon_setup_interrupt(struct octeon_device *oct)
 	return 0;
 }
 
+static int liquidio_watchdog(void *param)
+{
+	u64 wdog;
+	u16 mask_of_stuck_cores = 0;
+	u16 mask_of_crashed_cores = 0;
+	int core_num;
+	u8 core_is_stuck[LIO_MAX_CORES];
+	u8 core_crashed[LIO_MAX_CORES];
+	struct octeon_device *oct = param;
+
+	memset(core_is_stuck, 0, sizeof(core_is_stuck));
+	memset(core_crashed, 0, sizeof(core_crashed));
+
+	while (!kthread_should_stop()) {
+		mask_of_crashed_cores =
+		    (u16)octeon_read_csr64(oct, CN23XX_SLI_SCRATCH2);
+
+		for (core_num = 0; core_num < LIO_MAX_CORES; core_num++) {
+			if (!core_is_stuck[core_num]) {
+				wdog = lio_pci_readq(oct, CIU3_WDOG(core_num));
+
+				/* look at watchdog state field */
+				wdog &= CIU3_WDOG_MASK;
+				if (wdog) {
+					/* this watchdog timer has expired */
+					core_is_stuck[core_num] =
+						LIO_MONITOR_WDOG_EXPIRE;
+					mask_of_stuck_cores |= (1 << core_num);
+				}
+			}
+
+			if (!core_crashed[core_num])
+				core_crashed[core_num] =
+				    (mask_of_crashed_cores >> core_num) & 1;
+		}
+
+		if (mask_of_stuck_cores) {
+			for (core_num = 0; core_num < LIO_MAX_CORES;
+			     core_num++) {
+				if (core_is_stuck[core_num] == 1) {
+					dev_err(&oct->pci_dev->dev,
+						"ERROR: Octeon core %d is stuck!\n",
+						core_num);
+					/* 2 means we have printk'd  an error
+					 * so no need to repeat the same printk
+					 */
+					core_is_stuck[core_num] =
+						LIO_MONITOR_CORE_STUCK_MSGD;
+				}
+			}
+		}
+
+		if (mask_of_crashed_cores) {
+			for (core_num = 0; core_num < LIO_MAX_CORES;
+			     core_num++) {
+				if (core_crashed[core_num] == 1) {
+					dev_err(&oct->pci_dev->dev,
+						"ERROR: Octeon core %d crashed!  See oct-fwdump for details.\n",
+						core_num);
+					/* 2 means we have printk'd  an error
+					 * so no need to repeat the same printk
+					 */
+					core_crashed[core_num] =
+						LIO_MONITOR_CORE_STUCK_MSGD;
+				}
+			}
+		}
+#ifdef CONFIG_MODULE_UNLOAD
+		if (mask_of_stuck_cores || mask_of_crashed_cores) {
+			/* make module refcount=0 so that rmmod will work */
+			long refcount;
+
+			refcount = module_refcount(THIS_MODULE);
+
+			while (refcount > 0) {
+				module_put(THIS_MODULE);
+				refcount = module_refcount(THIS_MODULE);
+			}
+
+			/* compensate for and withstand an unlikely (but still
+			 * possible) race condition
+			 */
+			while (refcount < 0) {
+				try_module_get(THIS_MODULE);
+				refcount = module_refcount(THIS_MODULE);
+			}
+		}
+#endif
+		/* sleep for two seconds */
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(2 * HZ);
+	}
+
+	return 0;
+}
+
 /**
  * \brief PCI probe handler
  * @param pdev PCI device structure
@@ -1232,6 +1327,30 @@ liquidio_probe(struct pci_dev *pdev,
 		return -ENOMEM;
 	}
 
+	if (OCTEON_CN23XX_PF(oct_dev)) {
+		u64 scratch1;
+		u8 bus, device, function;
+
+		scratch1 = octeon_read_csr64(oct_dev, CN23XX_SLI_SCRATCH1);
+		if (!(scratch1 & 4ULL)) {
+			/* Bit 2 of SLI_SCRATCH_1 is a flag that indicates that
+			 * the lio watchdog kernel thread is running for this
+			 * NIC.  Each NIC gets one watchdog kernel thread.
+			 */
+			scratch1 |= 4ULL;
+			octeon_write_csr64(oct_dev, CN23XX_SLI_SCRATCH1,
+					   scratch1);
+
+			bus = pdev->bus->number;
+			device = PCI_SLOT(pdev->devfn);
+			function = PCI_FUNC(pdev->devfn);
+			oct_dev->watchdog_task = kthread_create(
+			    liquidio_watchdog, oct_dev,
+			    "liowd/%02hhx:%02hhx.%hhx", bus, device, function);
+			wake_up_process(oct_dev->watchdog_task);
+		}
+	}
+
 	oct_dev->rx_pause = 1;
 	oct_dev->tx_pause = 1;
 
@@ -1564,6 +1683,9 @@ static void liquidio_remove(struct pci_dev *pdev)
 
 	dev_dbg(&oct_dev->pci_dev->dev, "Stopping device\n");
 
+	if (oct_dev->watchdog_task)
+		kthread_stop(oct_dev->watchdog_task);
+
 	if (oct_dev->app_mode && (oct_dev->app_mode == CVM_DRV_NIC_APP))
 		liquidio_stop_nic_module(oct_dev);
 

drivers/net/ethernet/cavium/liquidio/octeon_device.h

@@ -484,6 +484,8 @@ struct octeon_device {
 
 	/* private flags to control driver-specific features through ethtool */
 	u32 priv_flags;
+
+	void *watchdog_task;
 };
 
 #define  OCT_DRV_ONLINE 1

drivers/net/ethernet/cavium/liquidio/octeon_network.h

@@ -131,6 +131,12 @@ struct lio {
 #define LIO_SIZE         (sizeof(struct lio))
 #define GET_LIO(netdev)  ((struct lio *)netdev_priv(netdev))
 
+#define CIU3_WDOG(c)                 (0x1010000020000ULL + (c << 3))
+#define CIU3_WDOG_MASK               12ULL
+#define LIO_MONITOR_WDOG_EXPIRE      1
+#define LIO_MONITOR_CORE_STUCK_MSGD  2
+#define LIO_MAX_CORES                12
+
 /**
  * \brief Enable or disable feature
  * @param netdev    pointer to network device