net/sfc: fix reading adapter state without locking

[ upstream commit 17b0d7b ]

Update MAC stats function reads adapter state with MAC stats locking
but without adapter locking. Add adapter locking before calling this
function and remove MAC stats locking since there's no point to have
it together with adapter locking. The second place MAC stats locking
is used is MAC stats reset function. It's called with adapter being
already locked so there's no point to use MAC stats locking anymore.

Fixes: 1caab2f ("net/sfc: add basic statistics")

Signed-off-by: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>

drivers/net/sfc/sfc.h

@@ -128,7 +128,6 @@ struct sfc_port {
 	unsigned int			nb_mcast_addrs;
 	uint8_t				*mcast_addrs;
 
-	rte_spinlock_t			mac_stats_lock;
 	uint64_t			*mac_stats_buf;
 	unsigned int			mac_stats_nb_supported;
 	efsys_mem_t			mac_stats_dma_mem;

drivers/net/sfc/sfc_ethdev.c

@@ -604,7 +604,7 @@ sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
 	uint64_t *mac_stats;
 	int ret;
 
-	rte_spinlock_lock(&port->mac_stats_lock);
+	sfc_adapter_lock(sa);
 
 	ret = sfc_port_update_mac_stats(sa);
 	if (ret != 0)
@@ -677,7 +677,7 @@ sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
 	}
 
 unlock:
-	rte_spinlock_unlock(&port->mac_stats_lock);
+	sfc_adapter_unlock(sa);
 	SFC_ASSERT(ret >= 0);
 	return -ret;
 }
@@ -689,19 +689,24 @@ sfc_stats_reset(struct rte_eth_dev *dev)
 	struct sfc_port *port = &sa->port;
 	int rc;
 
+	sfc_adapter_lock(sa);
+
 	if (sa->state != SFC_ADAPTER_STARTED) {
 		/*
 		 * The operation cannot be done if port is not started; it
 		 * will be scheduled to be done during the next port start
 		 */
 		port->mac_stats_reset_pending = B_TRUE;
+		sfc_adapter_unlock(sa);
 		return 0;
 	}
 
 	rc = sfc_port_reset_mac_stats(sa);
 	if (rc != 0)
 		sfc_err(sa, "failed to reset statistics (rc = %d)", rc);
 
+	sfc_adapter_unlock(sa);
+
 	SFC_ASSERT(rc >= 0);
 	return -rc;
 }
@@ -717,7 +722,7 @@ sfc_xstats_get(struct rte_eth_dev *dev, struct rte_eth_xstat *xstats,
 	unsigned int i;
 	int nstats = 0;
 
-	rte_spinlock_lock(&port->mac_stats_lock);
+	sfc_adapter_lock(sa);
 
 	rc = sfc_port_update_mac_stats(sa);
 	if (rc != 0) {
@@ -739,7 +744,7 @@ sfc_xstats_get(struct rte_eth_dev *dev, struct rte_eth_xstat *xstats,
 	}
 
 unlock:
-	rte_spinlock_unlock(&port->mac_stats_lock);
+	sfc_adapter_unlock(sa);
 
 	return nstats;
 }
@@ -780,7 +785,7 @@ sfc_xstats_get_by_id(struct rte_eth_dev *dev, const uint64_t *ids,
 	int ret;
 	int rc;
 
-	rte_spinlock_lock(&port->mac_stats_lock);
+	sfc_adapter_lock(sa);
 
 	if (unlikely(values == NULL) ||
 	    unlikely(ids == NULL && n < port->mac_stats_nb_supported)) {
@@ -810,7 +815,7 @@ sfc_xstats_get_by_id(struct rte_eth_dev *dev, const uint64_t *ids,
 	ret = nb_written;
 
 unlock:
-	rte_spinlock_unlock(&port->mac_stats_lock);
+	sfc_adapter_unlock(sa);
 
 	return ret;
 }
@@ -826,9 +831,14 @@ sfc_xstats_get_names_by_id(struct rte_eth_dev *dev,
 	unsigned int nb_written = 0;
 	unsigned int i;
 
+	sfc_adapter_lock(sa);
+
 	if (unlikely(xstats_names == NULL) ||
-	    unlikely((ids == NULL) && (size < port->mac_stats_nb_supported)))
-		return port->mac_stats_nb_supported;
+	    unlikely((ids == NULL) && (size < port->mac_stats_nb_supported))) {
+		nb_supported = port->mac_stats_nb_supported;
+		sfc_adapter_unlock(sa);
+		return nb_supported;
+	}
 
 	for (i = 0; (i < EFX_MAC_NSTATS) && (nb_written < size); ++i) {
 		if (!EFX_MAC_STAT_SUPPORTED(port->mac_stats_mask, i))
@@ -844,6 +854,8 @@ sfc_xstats_get_names_by_id(struct rte_eth_dev *dev,
 		++nb_supported;
 	}
 
+	sfc_adapter_unlock(sa);
+
 	return nb_written;
 }
 

drivers/net/sfc/sfc_port.c

@@ -43,7 +43,7 @@ sfc_port_update_mac_stats(struct sfc_adapter *sa)
 	unsigned int nb_attempts = 0;
 	int rc;
 
-	SFC_ASSERT(rte_spinlock_is_locked(&port->mac_stats_lock));
+	SFC_ASSERT(sfc_adapter_is_locked(sa));
 
 	if (sa->state != SFC_ADAPTER_STARTED)
 		return EINVAL;
@@ -103,14 +103,13 @@ sfc_port_reset_sw_stats(struct sfc_adapter *sa)
 int
 sfc_port_reset_mac_stats(struct sfc_adapter *sa)
 {
-	struct sfc_port *port = &sa->port;
 	int rc;
 
-	rte_spinlock_lock(&port->mac_stats_lock);
+	SFC_ASSERT(sfc_adapter_is_locked(sa));
+
 	rc = efx_mac_stats_clear(sa->nic);
 	if (rc == 0)
 		sfc_port_reset_sw_stats(sa);
-	rte_spinlock_unlock(&port->mac_stats_lock);
 
 	return rc;
 }
@@ -416,8 +415,6 @@ sfc_port_attach(struct sfc_adapter *sa)
 		goto fail_mcast_addr_list_buf_alloc;
 	}
 
-	rte_spinlock_init(&port->mac_stats_lock);
-
 	rc = ENOMEM;
 	port->mac_stats_buf = rte_calloc_socket("mac_stats_buf", EFX_MAC_NSTATS,
 						sizeof(uint64_t), 0,