Merge branch 'devlink-flash-update-overwrite-mask'

Jacob Keller says:

====================
devlink flash update overwrite mask

This series introduces support for a new attribute to the flash update
command: DEVLINK_ATTR_FLASH_UPDATE_OVERWRITE_MASK.

This attribute is a bitfield which allows userspace to specify what set of
subfields to overwrite when performing a flash update for a device.

The intention is to support the ability to control the behavior of
overwriting the configuration and identifying fields in the Intel ice device
flash update process. This is necessary  as the firmware layout for the ice
device includes some settings and configuration within the same flash
section as the main firmware binary.

This series, and the accompanying iproute2 series, introduce support for the
attribute. Once applied, the overwrite support can be be invoked via
devlink:

  # overwrite settings
  devlink dev flash pci/0000:af:00.0 file firmware.bin overwrite settings

  # overwrite identifiers and settings
  devlink dev flash pci/0000:af:00.0 file firmware.bin overwrite settings overwrite identifiers

To aid in the safe addition of new parameters, first some refactoring is
done to the .flash_update function: its parameters are converted from a
series of function arguments into a structure. This makes it easier to add
the new parameter without changing the signature of the .flash_update
handler in the future. Additionally, a "supported_flash_update_params" field
is added to devlink_ops. This field is similar to the ethtool
"supported_coalesc_params" field. The devlink core will now check that the
DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT bit is set before forwarding the
component attribute. Similarly, the new overwrite attribute will also
require a supported bit.

Doing these refactors will aid in adding any other attributes in the future,
and creates a good pattern for other interfaces to use in the future. By
requiring drivers to opt-in, we reduce the risk of accidentally breaking
drivers when ever we add an additional parameter. We also reduce boiler
plate code in drivers which do not support the parameters.

Changes since v9:
* rebased to current net-next, no other changes

Changes since v7
* resend, hopefully avoiding the SMTP server issues I experienced on Friday

Changes since v6
* Rebased to current net-next to resolve conflicts
* Added changes to the ionic driver that recently merged flash update support
* Fixed the changes for mlxsw to apply to core instead of spectrum.c after
  the recent refactor.
* Picked up the review tags from Jakub

Changes since v5
* Fix *all* of the BIT usage to use _BITUL() (thanks Jakub!)

Changes since v4
* Renamed nla_overwrite to nla_overwrite_mask at Jiri's suggestion
* Added "by this device" to the netlink error messages for unsupported
  attributes
* Removed use of BIT() in the uapi header
* Fixed the commit message for the netdevsim patch
* Picked up Jakub's reviewed
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 56 insertions, 2 deletions

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 4883dbae7faf..7339bf9ba6b4 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -550,6 +550,24 @@ enum devlink_param_generic_id {
 /* Firmware bundle identifier */
 #define DEVLINK_INFO_VERSION_GENERIC_FW_BUNDLE_ID	"fw.bundle_id"
 
+/**
+ * struct devlink_flash_update_params - Flash Update parameters
+ * @file_name: the name of the flash firmware file to update from
+ * @component: the flash component to update
+ *
+ * With the exception of file_name, drivers must opt-in to parameters by
+ * setting the appropriate bit in the supported_flash_update_params field in
+ * their devlink_ops structure.
+ */
+struct devlink_flash_update_params {
+	const char *file_name;
+	const char *component;
+	u32 overwrite_mask;
+};
+
+#define DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT		BIT(0)
+#define DEVLINK_SUPPORT_FLASH_UPDATE_OVERWRITE_MASK	BIT(1)
+
 struct devlink_region;
 struct devlink_info_req;
 
@@ -1037,6 +1055,12 @@ enum devlink_trap_group_generic_id {
 	}
 
 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,
@@ -1097,8 +1121,15 @@ struct devlink_ops {
 				      struct netlink_ext_ack *extack);
 	int (*info_get)(struct devlink *devlink, struct devlink_info_req *req,
 			struct netlink_ext_ack *extack);
-	int (*flash_update)(struct devlink *devlink, const char *file_name,
-			    const char *component,
+	/**
+	 * @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,
+			    struct devlink_flash_update_params *params,
 			    struct netlink_ext_ack *extack);
 	/**
 	 * @trap_init: Trap initialization function.
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index a2ecc8b00611..7b0face1bad5 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -230,6 +230,28 @@ enum {
 	DEVLINK_ATTR_STATS_MAX = __DEVLINK_ATTR_STATS_MAX - 1
 };
 
+/* Specify what sections of a flash component can be overwritten when
+ * performing an update. Overwriting of firmware binary sections is always
+ * implicitly assumed to be allowed.
+ *
+ * Each section must be documented in
+ * Documentation/networking/devlink/devlink-flash.rst
+ *
+ */
+enum {
+	DEVLINK_FLASH_OVERWRITE_SETTINGS_BIT,
+	DEVLINK_FLASH_OVERWRITE_IDENTIFIERS_BIT,
+
+	__DEVLINK_FLASH_OVERWRITE_MAX_BIT,
+	DEVLINK_FLASH_OVERWRITE_MAX_BIT = __DEVLINK_FLASH_OVERWRITE_MAX_BIT - 1
+};
+
+#define DEVLINK_FLASH_OVERWRITE_SETTINGS _BITUL(DEVLINK_FLASH_OVERWRITE_SETTINGS_BIT)
+#define DEVLINK_FLASH_OVERWRITE_IDENTIFIERS _BITUL(DEVLINK_FLASH_OVERWRITE_IDENTIFIERS_BIT)
+
+#define DEVLINK_SUPPORTED_FLASH_OVERWRITE_SECTIONS \
+	(_BITUL(__DEVLINK_FLASH_OVERWRITE_MAX_BIT) - 1)
+
 /**
  * enum devlink_trap_action - Packet trap action.
  * @DEVLINK_TRAP_ACTION_DROP: Packet is dropped by the device and a copy is not
@@ -464,6 +486,7 @@ enum devlink_attr {
 	DEVLINK_ATTR_PORT_CONTROLLER_NUMBER,	/* u32 */
 
 	DEVLINK_ATTR_FLASH_UPDATE_STATUS_TIMEOUT,	/* u64 */
+	DEVLINK_ATTR_FLASH_UPDATE_OVERWRITE_MASK,	/* bitfield32 */
 
 	/* add new attributes above here, update the policy in devlink.c */