[PATCH 1/7] firmware: arm_scmi: introduce helper get_max_msg_size

[Peng Fan (OSS)]

From: Peng Fan <peng.fan@xxxxxxx>

When Agent sending data to SCMI server, the Agent driver could check
the size to avoid protocol buffer overflow. So introduce the helper
get_max_msg_size.

Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---
 drivers/firmware/arm_scmi/driver.c    | 15 +++++++++++++++
 drivers/firmware/arm_scmi/protocols.h |  1 +
 2 files changed, 16 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index a9f70e6e58ac..b4f8f190351b 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1481,6 +1481,20 @@ static int scmi_common_extended_name_get(const struct scmi_protocol_handle *ph,
 	return ret;
 }
 
+/**
+ * scmi_common_get_max_msg_size  - Get maximum message size
+ * @ph: A protocol handle reference.
+ *
+ * Return: Maximum message size for the current protocol.
+ */
+static int scmi_common_get_max_msg_size(const struct scmi_protocol_handle *ph)
+{
+	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+	struct scmi_info *info = handle_to_scmi_info(pi->handle);
+
+	return info->desc->max_msg_size;
+}
+
 /**
  * struct scmi_iterator  - Iterator descriptor
  * @msg: A reference to the message TX buffer; filled by @prepare_message with
@@ -1756,6 +1770,7 @@ static void scmi_common_fastchannel_db_ring(struct scmi_fc_db_info *db)
 
 static const struct scmi_proto_helpers_ops helpers_ops = {
 	.extended_name_get = scmi_common_extended_name_get,
+	.get_max_msg_size = scmi_common_get_max_msg_size,
 	.iter_response_init = scmi_iterator_init,
 	.iter_response_run = scmi_iterator_run,
 	.fastchannel_init = scmi_common_fastchannel_init,
diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h
index e683c26f24eb..08de8dc064c1 100644
--- a/drivers/firmware/arm_scmi/protocols.h
+++ b/drivers/firmware/arm_scmi/protocols.h
@@ -270,6 +270,7 @@ struct scmi_proto_helpers_ops {
 				 void __iomem **p_addr,
 				 struct scmi_fc_db_info **p_db);
 	void (*fastchannel_db_ring)(struct scmi_fc_db_info *db);
+	int (*get_max_msg_size)(const struct scmi_protocol_handle *ph);
 };
 
 /**

-- 
2.37.1