net/mlx5: SF, Improve performance in SF allocation

Avoid second traversal on the SF table by recording the first free entry
and using it in case the looked up entry was not found in the table.

Signed-off-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sf/hw_table.c b/drivers/net/ethernet/mellanox/mlx5/core/sf/hw_table.c
index 500c71fb6f6d866afd04caa114c84e1767f6c0f7..d9c69123c1abc4c4bc7a5bbbaf54ef01cefacf08 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/sf/hw_table.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sf/hw_table.c
@@ -73,26 +73,29 @@ static int mlx5_sf_hw_table_id_alloc(struct mlx5_sf_hw_table *table, u32 control
                                     u32 usr_sfnum)
 {
        struct mlx5_sf_hwc_table *hwc;
+       int free_idx = -1;
        int i;
 
        hwc = mlx5_sf_controller_to_hwc(table->dev, controller);
        if (!hwc->sfs)
                return -ENOSPC;
 
-       /* Check if sf with same sfnum already exists or not. */
        for (i = 0; i < hwc->max_fn; i++) {
+               if (!hwc->sfs[i].allocated && free_idx == -1) {
+                       free_idx = i;
+                       continue;
+               }
+
                if (hwc->sfs[i].allocated && hwc->sfs[i].usr_sfnum == usr_sfnum)
                        return -EEXIST;
        }
-       /* Find the free entry and allocate the entry from the array */
-       for (i = 0; i < hwc->max_fn; i++) {
-               if (!hwc->sfs[i].allocated) {
-                       hwc->sfs[i].usr_sfnum = usr_sfnum;
-                       hwc->sfs[i].allocated = true;
-                       return i;
-               }
-       }
-       return -ENOSPC;
+
+       if (free_idx == -1)
+               return -ENOSPC;
+
+       hwc->sfs[free_idx].usr_sfnum = usr_sfnum;
+       hwc->sfs[free_idx].allocated = true;
+       return free_idx;
 }
 
 static void mlx5_sf_hw_table_id_free(struct mlx5_sf_hw_table *table, u32 controller, int id)