net/mlx5: Add last command failure syndrome to debugfs

Add syndrome of last command failure per command type to debugfs to ease
debugging of such failure.
last_failed_syndrome - last command failed syndrome returned by FW.
Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

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

@@ -1887,7 +1887,8 @@ static int cmd_exec(struct mlx5_core_dev *dev, void *in, int in_size, void *out,
 	return err;
 }
 
-static void cmd_status_log(struct mlx5_core_dev *dev, u16 opcode, u8 status, int err)
+static void cmd_status_log(struct mlx5_core_dev *dev, u16 opcode, u8 status,
+			   u32 syndrome, int err)
 {
 	struct mlx5_cmd_stats *stats;
 
@@ -1902,6 +1903,7 @@ static void cmd_status_log(struct mlx5_core_dev *dev, u16 opcode, u8 status, int
 	if (err == -EREMOTEIO) {
 		stats->failed_mbox_status++;
 		stats->last_failed_mbox_status = status;
+		stats->last_failed_syndrome = syndrome;
 	}
 	spin_unlock_irq(&stats->lock);
 }
@@ -1909,6 +1911,7 @@ static void cmd_status_log(struct mlx5_core_dev *dev, u16 opcode, u8 status, int
 /* preserve -EREMOTEIO for outbox.status != OK, otherwise return err as is */
 static int cmd_status_err(struct mlx5_core_dev *dev, int err, u16 opcode, void *out)
 {
+	u32 syndrome = MLX5_GET(mbox_out, out, syndrome);
 	u8 status = MLX5_GET(mbox_out, out, status);
 
 	if (err == -EREMOTEIO) /* -EREMOTEIO is preserved */
@@ -1917,7 +1920,7 @@ static int cmd_status_err(struct mlx5_core_dev *dev, int err, u16 opcode, void *
 	if (!err && status != MLX5_CMD_STAT_OK)
 		err = -EREMOTEIO;
 
-	cmd_status_log(dev, opcode, status, err);
+	cmd_status_log(dev, opcode, status, syndrome, err);
 	return err;
 }
 

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

@@ -192,6 +192,8 @@ void mlx5_cmdif_debugfs_init(struct mlx5_core_dev *dev)
 					   &stats->last_failed_errno);
 			debugfs_create_u8("last_failed_mbox_status", 0400, stats->root,
 					  &stats->last_failed_mbox_status);
+			debugfs_create_x32("last_failed_syndrome", 0400, stats->root,
+					   &stats->last_failed_syndrome);
 		}
 	}
 }

include/linux/mlx5/driver.h

@@ -272,6 +272,8 @@ struct mlx5_cmd_stats {
 	u32		last_failed_errno;
 	/* last bad status returned by FW */
 	u8		last_failed_mbox_status;
+	/* last command failed syndrome returned by FW */
+	u32		last_failed_syndrome;
 	struct dentry  *root;
 	/* protect command average calculations */
 	spinlock_t	lock;