IB/mlx4: Saturate RoCE port PMA counters in case of overflow

For RoCE ports, we set the u32 PMA values based on u64 HCA counters. In case of
overflow, according to the IB spec, we have to saturate a counter to its
max value, do that.

Fixes: c37791349cc7 ('IB/mlx4: Support PMA counters for IBoE')
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
index c7619716c31dd92cb5ddad4f77d98528392698b5..59040265e3614a23fc8508e88dd5b2138e7107e8 100644 (file)
--- a/drivers/infiniband/hw/mlx4/mad.c
+++ b/drivers/infiniband/hw/mlx4/mad.c
@@ -64,6 +64,14 @@ enum {
 #define GUID_TBL_BLK_NUM_ENTRIES 8
 #define GUID_TBL_BLK_SIZE (GUID_TBL_ENTRY_SIZE * GUID_TBL_BLK_NUM_ENTRIES)
 
+/* Counters should be saturate once they reach their maximum value */
+#define ASSIGN_32BIT_COUNTER(counter, value) do {\
+       if ((value) > U32_MAX)                   \
+               counter = cpu_to_be32(U32_MAX); \
+       else                                     \
+               counter = cpu_to_be32(value);    \
+} while (0)
+
 struct mlx4_mad_rcv_buf {
        struct ib_grh grh;
        u8 payload[256];
@@ -806,10 +814,14 @@ static int ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
 static void edit_counter(struct mlx4_counter *cnt,
                                        struct ib_pma_portcounters *pma_cnt)
 {
-       pma_cnt->port_xmit_data = cpu_to_be32((be64_to_cpu(cnt->tx_bytes)>>2));
-       pma_cnt->port_rcv_data  = cpu_to_be32((be64_to_cpu(cnt->rx_bytes)>>2));
-       pma_cnt->port_xmit_packets = cpu_to_be32(be64_to_cpu(cnt->tx_frames));
-       pma_cnt->port_rcv_packets  = cpu_to_be32(be64_to_cpu(cnt->rx_frames));
+       ASSIGN_32BIT_COUNTER(pma_cnt->port_xmit_data,
+                            (be64_to_cpu(cnt->tx_bytes) >> 2));
+       ASSIGN_32BIT_COUNTER(pma_cnt->port_rcv_data,
+                            (be64_to_cpu(cnt->rx_bytes) >> 2));
+       ASSIGN_32BIT_COUNTER(pma_cnt->port_xmit_packets,
+                            be64_to_cpu(cnt->tx_frames));
+       ASSIGN_32BIT_COUNTER(pma_cnt->port_rcv_packets,
+                            be64_to_cpu(cnt->rx_frames));
 }
 
 static int iboe_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,