devlink: check flash_update parameter support in net core

When implementing .flash_update, drivers which do not support
per-component update are manually checking the component parameter to
verify that it is NULL. Without this check, the driver might accept an
update request with a component specified even though it will not honor
such a request.

Instead of having each driver check this, move the logic into
net/core/devlink.c, and use a new `supported_flash_update_params` field
in the devlink_ops. Drivers which will support per-component update must
now specify this by setting DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT in
the supported_flash_update_params in their devlink_ops.

This helps ensure that drivers do not forget to check for a NULL
component if they do not support per-component update. This also enables
a slightly better error message by enabling the core stack to set the
netlink bad attribute message to indicate precisely the unsupported
attribute in the message.

Going forward, any new additional parameter to flash update will require
a bit in the supported_flash_update_params bitfield.

Signed-off-by: Jacob Keller <[e-mail]>
Reviewed-by: Jakub Kicinski <[e-mail]>
Cc: Jiri Pirko <[e-mail]>
Cc: Jonathan Corbet <[e-mail]>
Cc: Michael Chan <[e-mail]>
Cc: Bin Luo <[e-mail]>
Cc: Saeed Mahameed <[e-mail]>
Cc: Leon Romanovsky <[e-mail]>
Cc: Ido Schimmel <[e-mail]>
Cc: Danielle Ratson <[e-mail]>
Cc: Shannon Nelson <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c

···
 	struct bnxt *bp = bnxt_get_bp_from_dl(dl);
 	int rc;
 
-	if (region)
-		return -EOPNOTSUPP;
-
 	if (!BNXT_PF(bp)) {
 		NL_SET_ERR_MSG_MOD(extack,
 				   "flash update not supported from a VF");
···
 	}
 
 	devlink_flash_update_begin_notify(dl);
-	devlink_flash_update_status_notify(dl, "Preparing to flash", region, 0,
-					   0);
+	devlink_flash_update_status_notify(dl, "Preparing to flash", NULL, 0, 0);
 	rc = bnxt_flash_package_from_file(bp->dev, filename, 0);
 	if (!rc)
-		devlink_flash_update_status_notify(dl, "Flashing done", region,
-						   0, 0);
+		devlink_flash_update_status_notify(dl, "Flashing done", NULL, 0, 0);
 	else
-		devlink_flash_update_status_notify(dl, "Flashing failed",
-						   region, 0, 0);
+		devlink_flash_update_status_notify(dl, "Flashing failed", NULL, 0, 0);
 	devlink_flash_update_end_notify(dl);
 	return rc;
 }

drivers/net/ethernet/huawei/hinic/hinic_devlink.c

···
 	const struct firmware *fw;
 	int err;
 
-	if (component)
-		return -EOPNOTSUPP;
-
 	err = request_firmware_direct(&fw, file_name,
 				      &priv->hwdev->hwif->pdev->dev);
 	if (err)

drivers/net/ethernet/intel/ice/ice_devlink.c

···
 	const struct firmware *fw;
 	int err;
 
-	/* individual component update is not yet supported */
-	if (component)
-		return -EOPNOTSUPP;
-
 	if (!hw->dev_caps.common_cap.nvm_unified_update) {
 		NL_SET_ERR_MSG_MOD(extack, "Current firmware does not support unified update");
 		return -EOPNOTSUPP;
 	}
 
-	err = ice_check_for_pending_update(pf, component, extack);
+	err = ice_check_for_pending_update(pf, NULL, extack);
 	if (err)
 		return err;
 
···
 	}
 
 	devlink_flash_update_begin_notify(devlink);
-	devlink_flash_update_status_notify(devlink, "Preparing to flash",
-					   component, 0, 0);
+	devlink_flash_update_status_notify(devlink, "Preparing to flash", NULL, 0, 0);
 	err = ice_flash_pldm_image(pf, fw, extack);
 	devlink_flash_update_end_notify(devlink);
 

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

···
 	const struct firmware *fw;
 	int err;
 
-	if (component)
-		return -EOPNOTSUPP;
-
 	err = request_firmware_direct(&fw, file_name, &dev->pdev->dev);
 	if (err)
 		return err;

drivers/net/ethernet/mellanox/mlxsw/core.c

···
 	const struct firmware *firmware;
 	int err;
 
-	if (component)
-		return -EOPNOTSUPP;
-
 	err = request_firmware_direct(&firmware, file_name, mlxsw_core->bus_info->dev);
 	if (err)
 		return err;

drivers/net/ethernet/netronome/nfp/nfp_devlink.c

···
 nfp_devlink_flash_update(struct devlink *devlink, const char *path,
 			 const char *component, struct netlink_ext_ack *extack)
 {
-	if (component)
-		return -EOPNOTSUPP;
 	return nfp_flash_update_common(devlink_priv(devlink), path, extack);
 }
 

drivers/net/ethernet/pensando/ionic/ionic_devlink.c

···
 {
 	struct ionic *ionic = devlink_priv(dl);
 
-	if (component)
-		return -EOPNOTSUPP;
-
 	return ionic_firmware_update(ionic->lif, fwname, extack);
 }
 

drivers/net/netdevsim/dev.c

···
 }
 
 static const struct devlink_ops nsim_dev_devlink_ops = {
+	.supported_flash_update_params = DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT,
 	.reload_down = nsim_dev_reload_down,
 	.reload_up = nsim_dev_reload_up,
 	.info_get = nsim_dev_info_get,

include/net/devlink.h

···
 /* Firmware bundle identifier */
 #define DEVLINK_INFO_VERSION_GENERIC_FW_BUNDLE_ID	"fw.bundle_id"
 
+#define DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT	BIT(0)
+
 struct devlink_region;
 struct devlink_info_req;
 
···
 	}
 
 struct devlink_ops {
+	/**
+	 * @supported_flash_update_params:
+	 * mask of parameters supported by the driver's .flash_update
+	 * implemementation.
+	 */
+	u32 supported_flash_update_params;
 	int (*reload_down)(struct devlink *devlink, bool netns_change,
 			   struct netlink_ext_ack *extack);
 	int (*reload_up)(struct devlink *devlink,
···
 				      struct netlink_ext_ack *extack);
 	int (*info_get)(struct devlink *devlink, struct devlink_info_req *req,
 			struct netlink_ext_ack *extack);
+	/**
+	 * @flash_update: Device flash update function
+	 *
+	 * Used to perform a flash update for the device. The set of
+	 * parameters supported by the driver should be set in
+	 * supported_flash_update_params.
+	 */
 	int (*flash_update)(struct devlink *devlink, const char *file_name,
 			    const char *component,
 			    struct netlink_ext_ack *extack);

net/core/devlink.c

···
 				       struct genl_info *info)
 {
 	struct devlink *devlink = info->user_ptr[0];
-	const char *file_name, *component;
+	const char *file_name, *component = NULL;
 	struct nlattr *nla_component;
+	u32 supported_params;
 
 	if (!devlink->ops->flash_update)
 		return -EOPNOTSUPP;
 
 	if (!info->attrs[DEVLINK_ATTR_FLASH_UPDATE_FILE_NAME])
 		return -EINVAL;
+
+	supported_params = devlink->ops->supported_flash_update_params;
+
 	file_name = nla_data(info->attrs[DEVLINK_ATTR_FLASH_UPDATE_FILE_NAME]);
 
 	nla_component = info->attrs[DEVLINK_ATTR_FLASH_UPDATE_COMPONENT];
-	component = nla_component ? nla_data(nla_component) : NULL;
+	if (nla_component) {
+		if (!(supported_params & DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT)) {
+			NL_SET_ERR_MSG_ATTR(info->extack, nla_component,
+					    "component update is not supported by this device");
+			return -EOPNOTSUPP;
+		}
+		component = nla_data(nla_component);
+	}
 
 	return devlink->ops->flash_update(devlink, file_name, component,
 					  info->extack);