RDMA/mlx5: Fix mlx5 rates to IB rates map

Correct the map between mlx5 rates and corresponding ib rates, as they
don't always have a fixed offset between them.

Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Zhang <[e-mail]>
Reviewed-by: Maor Gottlieb <[e-mail]>
Signed-off-by: Leon Romanovsky <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>

drivers/infiniband/hw/mlx5/qp.c

···
 	MLX5_PATH_FLAG_COUNTER	= 1 << 2,
 };
 
+static int mlx5_to_ib_rate_map(u8 rate)
+{
+	static const int rates[] = { IB_RATE_PORT_CURRENT, IB_RATE_56_GBPS,
+				     IB_RATE_25_GBPS,	   IB_RATE_100_GBPS,
+				     IB_RATE_200_GBPS,	   IB_RATE_50_GBPS,
+				     IB_RATE_400_GBPS };
+
+	if (rate < ARRAY_SIZE(rates))
+		return rates[rate];
+
+	return rate - MLX5_STAT_RATE_OFFSET;
+}
+
 static int ib_to_mlx5_rate_map(u8 rate)
 {
 	switch (rate) {
···
 	rdma_ah_set_path_bits(ah_attr, MLX5_GET(ads, path, mlid));
 
 	static_rate = MLX5_GET(ads, path, stat_rate);
-	rdma_ah_set_static_rate(ah_attr, static_rate ? static_rate - 5 : 0);
+	rdma_ah_set_static_rate(ah_attr, mlx5_to_ib_rate_map(static_rate));
 	if (MLX5_GET(ads, path, grh) ||
 	    ah_attr->type == RDMA_AH_ATTR_TYPE_ROCE) {
 		rdma_ah_set_grh(ah_attr, NULL, MLX5_GET(ads, path, flow_label),