releases/5.10.94/net-mlx5-set-command-entry-semaphore-up-once-got-ind.patch

   1 From 65e1119397a202a42d4448990ba3d20ea0d83d42 Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Sun, 5 Dec 2021 12:07:49 +0200
   4 Subject: net/mlx5: Set command entry semaphore up once got index free
   5
   6 From: Moshe Shemesh <moshe@nvidia.com>
   7
   8 [ Upstream commit 8e715cd613a1e872b9d918e912d90b399785761a ]
   9
  10 Avoid a race where command work handler may fail to allocate command
  11 entry index, by holding the command semaphore down till command entry
  12 index is being freed.
  13
  14 Fixes: 410bd754cd73 ("net/mlx5: Add retry mechanism to the command entry index allocation")
  15 Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
  16 Reviewed-by: Eran Ben Elisha <eranbe@nvidia.com>
  17 Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
  18 Signed-off-by: Sasha Levin <sashal@kernel.org>
  19 ---
  20  drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 15 ++++++---------
  21  1 file changed, 6 insertions(+), 9 deletions(-)
  22
  23 diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
  24 index 2e55e00888715..20e3f8cd074a1 100644
  25 --- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
  26 +++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
  27 @@ -147,8 +147,12 @@ static void cmd_ent_put(struct mlx5_cmd_work_ent *ent)
  28         if (!refcount_dec_and_test(&ent->refcnt))
  29                 return;
  30
  31 -       if (ent->idx >= 0)
  32 -               cmd_free_index(ent->cmd, ent->idx);
  33 +       if (ent->idx >= 0) {
  34 +               struct mlx5_cmd *cmd = ent->cmd;
  35 +
  36 +               cmd_free_index(cmd, ent->idx);
  37 +               up(ent->page_queue ? &cmd->pages_sem : &cmd->sem);
  38 +       }
  39
  40         cmd_free_ent(ent);
  41  }
  42 @@ -1582,8 +1586,6 @@ static void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, u64 vec, bool force
  43         vector = vec & 0xffffffff;
  44         for (i = 0; i < (1 << cmd->log_sz); i++) {
  45                 if (test_bit(i, &vector)) {
  46 -                       struct semaphore *sem;
  47 -
  48                         ent = cmd->ent_arr[i];
  49
  50                         /* if we already completed the command, ignore it */
  51 @@ -1606,10 +1608,6 @@ static void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, u64 vec, bool force
  52                             dev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR)
  53                                 cmd_ent_put(ent);
  54
  55 -                       if (ent->page_queue)
  56 -                               sem = &cmd->pages_sem;
  57 -                       else
  58 -                               sem = &cmd->sem;
  59                         ent->ts2 = ktime_get_ns();
  60                         memcpy(ent->out->first.data, ent->lay->out, sizeof(ent->lay->out));
  61                         dump_command(dev, ent, 0);
  62 @@ -1663,7 +1661,6 @@ static void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, u64 vec, bool force
  63                                  */
  64                                 complete(&ent->done);
  65                         }
  66 -                       up(sem);
  67                 }
  68         }
  69  }
  70 --
  71 2.34.1
  72