diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index a2efdaa020b0..2a34485f7e0a 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -858,8 +858,8 @@ int64_t opal_lpc_write(uint32_t chip_id, enum OpalLPCAddressType addr_type,
 int64_t opal_lpc_read(uint32_t chip_id, enum OpalLPCAddressType addr_type,
 		      uint32_t addr, __be32 *data, uint32_t sz);
 
-int64_t opal_read_elog(uint64_t buffer, size_t size, uint64_t log_id);
-int64_t opal_get_elog_size(uint64_t *log_id, size_t *size, uint64_t *elog_type);
+int64_t opal_read_elog(uint64_t buffer, uint64_t size, uint64_t log_id);
+int64_t opal_get_elog_size(uint64_t *log_id, uint64_t *size, uint64_t *elog_type);
 int64_t opal_write_elog(uint64_t buffer, uint64_t size, uint64_t offset);
 int64_t opal_send_ack_elog(uint64_t log_id);
 void opal_resend_pending_logs(void);
@@ -874,13 +874,13 @@ int64_t opal_dump_read(uint32_t dump_id, uint64_t buffer);
 int64_t opal_dump_ack(uint32_t dump_id);
 int64_t opal_dump_resend_notification(void);
 
-int64_t opal_get_msg(uint64_t buffer, size_t size);
-int64_t opal_check_completion(uint64_t buffer, size_t size, uint64_t token);
+int64_t opal_get_msg(uint64_t buffer, uint64_t size);
+int64_t opal_check_completion(uint64_t buffer, uint64_t size, uint64_t token);
 int64_t opal_sync_host_reboot(void);
 int64_t opal_get_param(uint64_t token, uint32_t param_id, uint64_t buffer,
-		size_t length);
+		uint64_t length);
 int64_t opal_set_param(uint64_t token, uint32_t param_id, uint64_t buffer,
-		size_t length);
+		uint64_t length);
 int64_t opal_sensor_read(uint32_t sensor_hndl, int token, __be32 *sensor_data);
 
 /* Internal functions */
diff --git a/arch/powerpc/platforms/powernv/opal-elog.c b/arch/powerpc/platforms/powernv/opal-elog.c
index ef7bc2a97862..7e3821e611a8 100644
--- a/arch/powerpc/platforms/powernv/opal-elog.c
+++ b/arch/powerpc/platforms/powernv/opal-elog.c
@@ -238,7 +238,7 @@ static struct elog_obj *create_elog_obj(uint64_t id, size_t size, uint64_t type)
 
 static void elog_work_fn(struct work_struct *work)
 {
-	size_t elog_size;
+	uint64_t elog_size;
 	uint64_t log_id;
 	uint64_t elog_type;
 	int rc;