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

commit 61a3855bb726cbb062ef02a31a832dea455456e0 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
index 4d599cedbb0b1ccceab997a4945be0d8d6e89fde..6ee534874535729a389de8808922332696be0f5f 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];
@@ -730,10 +738,14 @@ 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,