[PATCH 4.14 103/209] IB/rxe: Make counters thread safe

Greg Kroah-Hartman
2019-12-04T18:22:39Z

From: Parav Pandit <parav@mellanox.com>

[ Upstream commit d5108e69fe013ff47ab815b849caba9cc33ca1e5 ]

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: 0b1e5b99a48b ("IB/rxe: Add port protocol stats")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/sw/rxe/rxe_hw_counters.c | 2 +-
drivers/infiniband/sw/rxe/rxe_verbs.h | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_hw_counters.c b/drivers/infiniband/sw/rxe/rxe_hw_counters.c
index 6aeb7a165e469..ea4542a9d69e6 100644
--- a/drivers/infiniband/sw/rxe/rxe_hw_counters.c
+++ b/drivers/infiniband/sw/rxe/rxe_hw_counters.c
@@ -59,7 +59,7 @@ 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);
}
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
index b2b76a316ebae..d1cc89f6f2e33 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.h
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
@@ -410,16 +410,16 @@ 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)
--
2.20.1