IB/rxe: Make counters thread safe

Current rxe device counters are not thread safe.
When multiple QPs are used, they can be racy.
Make them thread safe by making it atomic64.

Fixes: 0b1e5b99 ("IB/rxe: Add port protocol stats")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/sw/rxe/rxe_hw_counters.c

@@ -62,7 +62,7 @@ int rxe_ib_get_hw_stats(struct ib_device *ibdev,
 		return -EINVAL;
 
 	for (cnt = 0; cnt  < ARRAY_SIZE(rxe_counter_name); cnt++)
-		stats->value[cnt] = dev->stats_counters[cnt];
+		stats->value[cnt] = atomic64_read(&dev->stats_counters[cnt]);
 
 	return ARRAY_SIZE(rxe_counter_name);
 }

drivers/infiniband/sw/rxe/rxe_verbs.h

@@ -409,16 +409,16 @@ struct rxe_dev {
 	spinlock_t		mmap_offset_lock; /* guard mmap_offset */
 	int			mmap_offset;
 
-	u64			stats_counters[RXE_NUM_OF_COUNTERS];
+	atomic64_t		stats_counters[RXE_NUM_OF_COUNTERS];
 
 	struct rxe_port		port;
 	struct list_head	list;
 	struct crypto_shash	*tfm;
 };
 
-static inline void rxe_counter_inc(struct rxe_dev *rxe, enum rxe_counters cnt)
+static inline void rxe_counter_inc(struct rxe_dev *rxe, enum rxe_counters index)
 {
-	rxe->stats_counters[cnt]++;
+	atomic64_inc(&rxe->stats_counters[index]);
 }
 
 static inline struct rxe_dev *to_rdev(struct ib_device *dev)