qcacmn: Register for panic notification

If wlan logging is enabled then register a notifier block
to kernel's panic notifier chain. Notifier block contains a
callback function to print buffered wlan logs in the event
of kernel panic.

Change-Id: Id8cae651afe45e411e1ddf122c2bc9b5f6688327
CRs-Fixed: 2692163

utils/logging/inc/wlan_logging_sock_svc.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2019 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014-2020 The Linux Foundation. All rights reserved.
  *
  * Permission to use, copy, modify, and/or distribute this software for
  * any purpose with or without fee is hereby granted, provided that the
@@ -46,6 +46,28 @@ int wlan_log_to_user(QDF_TRACE_LEVEL log_level, char *to_be_sent, int length);
  */
 int wlan_logging_set_flush_timer(uint32_t milliseconds);
 
+/**
+ * wlan_logging_notifier_init() - registers to panic notifier chain
+ * @dump_at_kernel_enable: qdf logging at kernel level enabled
+ *
+ * This function registers an handler to panic notifier chain if
+ * qdf logging at kernel level is disabled.
+ *
+ * Return: 0 on success
+ */
+int wlan_logging_notifier_init(bool dump_at_kernel_enable);
+
+/**
+ * wlan_logging_notifier_deinit() - unregisters to panic notifier chain
+ * @dump_at_kernel_enable: qdf logging at kernel level enabled
+ *
+ * This function unregisters an handler to panic notifier chain if
+ * qdf logging at kernel level is disabled.
+ *
+ * Return: 0 on success
+ */
+int wlan_logging_notifier_deinit(bool dump_at_kernel_enable);
+
 #ifdef WLAN_LOGGING_SOCK_SVC_ENABLE
 void wlan_logging_set_per_pkt_stats(void);
 void wlan_logging_set_fw_flush_complete(void);