Add encode/decode for EventMessageBufferSize

Added encode API for EventMessageBufferSize command(0x0D) which
is defined in DSP02408 Version 1.2.1 sec:16.9.

Signed-off-by: Dung Cao <dung@os.amperecomputing.com>
Change-Id: Id3f00706b3d3a1871aa6491cc0ffe2ee42597258
diff --git a/include/libpldm/platform.h b/include/libpldm/platform.h
index 8ef0f76..f0eea51 100644
--- a/include/libpldm/platform.h
+++ b/include/libpldm/platform.h
@@ -26,6 +26,11 @@
 #define PLDM_GET_PDR_REQ_BYTES 13
 
 #define PLDM_SET_EVENT_RECEIVER_RESP_BYTES 1
+
+/* Platform event supported request */
+#define PLDM_EVENT_MESSAGE_BUFFER_SIZE_REQ_BYTES 2
+#define PLDM_EVENT_MESSAGE_BUFFER_SIZE_RESP_BYTES 3
+
 /* Minimum response length */
 #define PLDM_GET_PDR_MIN_RESP_BYTES 12
 #define PLDM_GET_NUMERIC_EFFECTER_VALUE_MIN_RESP_BYTES 5
@@ -115,6 +120,8 @@
 
 enum pldm_platform_commands {
 	PLDM_SET_EVENT_RECEIVER = 0x04,
+	PLDM_PLATFORM_EVENT_MESSAGE = 0x0A,
+	PLDM_EVENT_MESSAGE_BUFFER_SIZE = 0xD,
 	PLDM_GET_SENSOR_READING = 0x11,
 	PLDM_GET_STATE_SENSOR_READINGS = 0x21,
 	PLDM_SET_NUMERIC_EFFECTER_VALUE = 0x31,
@@ -122,7 +129,6 @@
 	PLDM_SET_STATE_EFFECTER_STATES = 0x39,
 	PLDM_GET_PDR_REPOSITORY_INFO = 0x50,
 	PLDM_GET_PDR = 0x51,
-	PLDM_PLATFORM_EVENT_MESSAGE = 0x0A
 };
 
 /** @brief PLDM PDR types
@@ -747,6 +753,23 @@
 	uint16_t heartbeat_timer;
 } __attribute__((packed));
 
+/** @struct pldm_event_message_buffer_size_req
+ *
+ *  Structure representing EventMessageBufferSizes command request data
+ */
+struct pldm_event_message_buffer_size_req {
+	uint16_t event_receiver_max_buffer_size;
+} __attribute__((packed));
+
+/** @struct pldm_event_message_buffer_size_resp
+ *
+ *  Structure representing EventMessageBufferSizes command response data
+ */
+struct pldm_event_message_buffer_size_resp {
+	uint8_t completion_code;
+	uint16_t terminus_max_buffer_size;
+} __attribute__((packed));
+
 /** @struct pldm_set_numeric_effecter_value_req
  *
  *  structure representing SetNumericEffecterValue request packet
@@ -1418,6 +1441,29 @@
 				       uint8_t *completion_code,
 				       uint8_t *platform_event_status);
 
+/** @brief Decode EventMessageBufferSize response data
+ *  @param[in] msg - Request message
+ *  @param[in] payload_length - Length of Response message payload
+ *  @param[out] completion_code - PLDM completion code
+ *  @return pldm_completion_codes
+ */
+int decode_event_message_buffer_size_resp(const struct pldm_msg *msg,
+					  size_t payload_length,
+					  uint8_t *completion_code,
+					  uint16_t *terminus_max_buffer_size);
+
+/** @brief Encode EventMessageBufferSize request data
+ *  @param[in] instance_id - Message's instance id
+ *  @param[in] event_receiver_max_buffer_size - Max buffer size
+ *  @param[out] msg - Request message
+ *  @return pldm_completion_codes
+ *  @note Caller is responsible for memory alloc and dealloc of param
+ *  'msg.payload'
+ */
+int encode_event_message_buffer_size_req(
+    uint8_t instance_id, uint16_t event_receiver_max_buffer_size,
+    struct pldm_msg *msg);
+
 /** @brief Decode sensorEventData response data
  *
  *  @param[in] event_data - event data from the response message