From 7d627137dc1062aba6276a7d2ebe7f5ff8d542c5 Mon Sep 17 00:00:00 2001 From: Dragos Tatulea Date: Fri, 16 Aug 2024 12:01:50 +0300 Subject: net/mlx5: Support throttled commands from async API Currently, commands that qualify as throttled can't be used via the async API. That's due to the fact that the throttle semaphore can sleep but the async API can't. This patch allows throttling in the async API by using the tentative variant of the semaphore and upon failure (semaphore at 0) returns EBUSY to signal to the caller that they need to wait for the completion of previously issued commands. Furthermore, make sure that the semaphore is released in the callback. Signed-off-by: Dragos Tatulea Cc: Leon Romanovsky Reviewed-by: Tariq Toukan Message-Id: <20240816090159.1967650-2-dtatulea@nvidia.com> Signed-off-by: Michael S. Tsirkin Tested-by: Lei Yang --- drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'drivers/net/ethernet/mellanox') diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c index 20768ef2e9d2..f69c977c1569 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c @@ -1882,10 +1882,12 @@ static int cmd_exec(struct mlx5_core_dev *dev, void *in, int in_size, void *out, throttle_op = mlx5_cmd_is_throttle_opcode(opcode); if (throttle_op) { - /* atomic context may not sleep */ - if (callback) - return -EINVAL; - down(&dev->cmd.vars.throttle_sem); + if (callback) { + if (down_trylock(&dev->cmd.vars.throttle_sem)) + return -EBUSY; + } else { + down(&dev->cmd.vars.throttle_sem); + } } pages_queue = is_manage_pages(in); @@ -2091,10 +2093,19 @@ static void mlx5_cmd_exec_cb_handler(int status, void *_work) { struct mlx5_async_work *work = _work; struct mlx5_async_ctx *ctx; + struct mlx5_core_dev *dev; + u16 opcode; ctx = work->ctx; - status = cmd_status_err(ctx->dev, status, work->opcode, work->op_mod, work->out); + dev = ctx->dev; + opcode = work->opcode; + status = cmd_status_err(dev, status, work->opcode, work->op_mod, work->out); work->user_callback(status, work); + /* Can't access "work" from this point on. It could have been freed in + * the callback. + */ + if (mlx5_cmd_is_throttle_opcode(opcode)) + up(&dev->cmd.vars.throttle_sem); if (atomic_dec_and_test(&ctx->num_inflight)) complete(&ctx->inflight_done); } -- cgit v1.2.3