net/mlx4_core: Use devlink region_snapshot parameter

This parameter enables capturing region snapshot of the crspace
during critical errors. The default value of this parameter is
disabled, it can be enabled using devlink param commands.
It is possible to configure during runtime and also driver init.
Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/crdump.c

@@ -158,6 +158,7 @@ static void mlx4_crdump_collect_fw_health(struct mlx4_dev *dev,
 int mlx4_crdump_collect(struct mlx4_dev *dev)
 {
 	struct devlink *devlink = priv_to_devlink(mlx4_priv(dev));
+	struct mlx4_fw_crdump *crdump = &dev->persist->crdump;
 	struct pci_dev *pdev = dev->persist->pdev;
 	unsigned long cr_res_size;
 	u8 __iomem *cr_space;
@@ -168,6 +169,11 @@ int mlx4_crdump_collect(struct mlx4_dev *dev)
 		return 0;
 	}
 
+	if (!crdump->snapshot_enable) {
+		mlx4_info(dev, "crdump: devlink snapshot disabled, skipping\n");
+		return 0;
+	}
+
 	cr_res_size = pci_resource_len(pdev, 0);
 
 	cr_space = ioremap(pci_resource_start(pdev, 0), cr_res_size);
@@ -197,6 +203,8 @@ int mlx4_crdump_init(struct mlx4_dev *dev)
 	struct mlx4_fw_crdump *crdump = &dev->persist->crdump;
 	struct pci_dev *pdev = dev->persist->pdev;
 
+	crdump->snapshot_enable = false;
+
 	/* Create cr-space region */
 	crdump->region_crspace =
 		devlink_region_create(devlink,

drivers/net/ethernet/mellanox/mlx4/main.c

@@ -191,6 +191,26 @@ static int mlx4_devlink_ierr_reset_set(struct devlink *devlink, u32 id,
 	return 0;
 }
 
+static int mlx4_devlink_crdump_snapshot_get(struct devlink *devlink, u32 id,
+					    struct devlink_param_gset_ctx *ctx)
+{
+	struct mlx4_priv *priv = devlink_priv(devlink);
+	struct mlx4_dev *dev = &priv->dev;
+
+	ctx->val.vbool = dev->persist->crdump.snapshot_enable;
+	return 0;
+}
+
+static int mlx4_devlink_crdump_snapshot_set(struct devlink *devlink, u32 id,
+					    struct devlink_param_gset_ctx *ctx)
+{
+	struct mlx4_priv *priv = devlink_priv(devlink);
+	struct mlx4_dev *dev = &priv->dev;
+
+	dev->persist->crdump.snapshot_enable = ctx->val.vbool;
+	return 0;
+}
+
 static int
 mlx4_devlink_max_macs_validate(struct devlink *devlink, u32 id,
 			       union devlink_param_value val,
@@ -224,6 +244,11 @@ static const struct devlink_param mlx4_devlink_params[] = {
 	DEVLINK_PARAM_GENERIC(MAX_MACS,
 			      BIT(DEVLINK_PARAM_CMODE_DRIVERINIT),
 			      NULL, NULL, mlx4_devlink_max_macs_validate),
+	DEVLINK_PARAM_GENERIC(REGION_SNAPSHOT,
+			      BIT(DEVLINK_PARAM_CMODE_RUNTIME) |
+			      BIT(DEVLINK_PARAM_CMODE_DRIVERINIT),
+			      mlx4_devlink_crdump_snapshot_get,
+			      mlx4_devlink_crdump_snapshot_set, NULL),
 	DEVLINK_PARAM_DRIVER(MLX4_DEVLINK_PARAM_ID_ENABLE_64B_CQE_EQE,
 			     "enable_64b_cqe_eqe", DEVLINK_PARAM_TYPE_BOOL,
 			     BIT(DEVLINK_PARAM_CMODE_DRIVERINIT),
@@ -270,6 +295,11 @@ static void mlx4_devlink_set_params_init_values(struct devlink *devlink)
 	mlx4_devlink_set_init_value(devlink,
 				    MLX4_DEVLINK_PARAM_ID_ENABLE_4K_UAR,
 				    value);
+
+	value.vbool = false;
+	mlx4_devlink_set_init_value(devlink,
+				    DEVLINK_PARAM_GENERIC_ID_REGION_SNAPSHOT,
+				    value);
 }
 
 static inline void mlx4_set_num_reserved_uars(struct mlx4_dev *dev,
@@ -3862,6 +3892,9 @@ static int mlx4_devlink_port_type_set(struct devlink_port *devlink_port,
 
 static void mlx4_devlink_param_load_driverinit_values(struct devlink *devlink)
 {
+	struct mlx4_priv *priv = devlink_priv(devlink);
+	struct mlx4_dev *dev = &priv->dev;
+	struct mlx4_fw_crdump *crdump = &dev->persist->crdump;
 	union devlink_param_value saved_value;
 	int err;
 
@@ -3889,6 +3922,14 @@ static void mlx4_devlink_param_load_driverinit_values(struct devlink *devlink)
 						 &saved_value);
 	if (!err)
 		enable_4k_uar = saved_value.vbool;
+	err = devlink_param_driverinit_value_get(devlink,
+						 DEVLINK_PARAM_GENERIC_ID_REGION_SNAPSHOT,
+						 &saved_value);
+	if (!err && crdump->snapshot_enable != saved_value.vbool) {
+		crdump->snapshot_enable = saved_value.vbool;
+		devlink_param_value_changed(devlink,
+					    DEVLINK_PARAM_GENERIC_ID_REGION_SNAPSHOT);
+	}
 }
 
 static int mlx4_devlink_reload(struct devlink *devlink,

include/linux/mlx4/device.h

@@ -853,6 +853,7 @@ struct mlx4_vf_dev {
 };
 
 struct mlx4_fw_crdump {
+	bool snapshot_enable;
 	struct devlink_region *region_crspace;
 	struct devlink_region *region_fw_health;
 };