Commit e1167e16 authored Apr 28, 2020 by Arnd Bergmann Committed by Saeed Mahameed May 29, 2020

net/mlx5: reduce stack usage in qp_read_field

Moving the mlx5_ifc_query_qp_out_bits structure on the stack was a bit
excessive and now causes the compiler to complain on 32-bit architectures:

drivers/net/ethernet/mellanox/mlx5/core/debugfs.c: In function 'qp_read_field':
drivers/net/ethernet/mellanox/mlx5/core/debugfs.c:274:1: error: the frame size of 1104 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

Revert the previous patch partially to use dynamically allocation as
the code did before. Unfortunately there is no good error handling
in case the allocation fails.

Fixes: 57a6c5e9 ("net/mlx5: Replace hand written QP context struct with automatic getters")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

parent 28619046

drivers/net/ethernet/mellanox/mlx5/core/debugfs.c

+9 −3

Original line number	Diff line number	Diff line
		@@ -202,18 +202,23 @@ void mlx5_cq_debugfs_cleanup(struct mlx5_core_dev *dev)
		static u64 qp_read_field(struct mlx5_core_dev dev, struct mlx5_core_qp qp,
		int index, int *is_str)
		{
		u32 out[MLX5_ST_SZ_BYTES(query_qp_out)] = {};
		int outlen = MLX5_ST_SZ_BYTES(query_qp_out);
		u32 in[MLX5_ST_SZ_DW(query_qp_in)] = {};
		u64 param = 0;
		u32 *out;
		int state;
		u32 *qpc;
		int err;

		out = kzalloc(outlen, GFP_KERNEL);
		if (!out)
		return 0;

		MLX5_SET(query_qp_in, in, opcode, MLX5_CMD_OP_QUERY_QP);
		MLX5_SET(query_qp_in, in, qpn, qp->qpn);
		err = mlx5_cmd_exec_inout(dev, query_qp, in, out);
		if (err)
		return 0;
		goto out;

		*is_str = 0;

		@@ -269,7 +274,8 @@ static u64 qp_read_field(struct mlx5_core_dev dev, struct mlx5_core_qp qp,
		param = MLX5_GET(qpc, qpc, remote_qpn);
		break;
		}

		out:
		kfree(out);
		return param;
		}

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