ath10k: Add wrapper function to ath10k debug

ath10k_dbg() is called in ath10k_process_rx() with huge set of arguments
which is causing CPU overhead even when debug_mask is not set.
Good improvement was observed in the receive side performance when call
to ath10k_dbg() is avoided in the RX path.

Since currently all debug messages are sent via tracing infrastructure,
we cannot entirely avoid calling ath10k_dbg. Therefore, call to
ath10k_dbg() is made conditional based on tracing config in the driver.

Trasmit performance remains unchanged with this patch; below are some
experimental results with this patch and tracing disabled.

mesh mode:

		w/o this patch          with this patch
Traffic       TP      CPU Usage      TP      CPU usage

TCP          840Mbps    76.53%      960Mbps    78.14%
UDP          1030Mbps   74.58%      1132Mbps   74.31%

Infra mode:

		w/o this patch          with this patch
Traffic        TP      CPU Usage      TP      CPU usage

TCP Rx       1241Mbps   80.89%      1270Mbps   73.50%
UDP Rx       1433Mbps   81.77%      1472Mbps   72.80%

Tested platform	: IPQ8064
hardware used	: QCA9984
firmware ver	: ver 10.4-3.5.3-00057
Signed-off-by: Kan Yan <kyan@chromium.org>
Signed-off-by: Venkateswara Naralasetty <vnaralas@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/ath10k/core.c

@@ -26,6 +26,8 @@
 #include "coredump.h"
 
 unsigned int ath10k_debug_mask;
+EXPORT_SYMBOL(ath10k_debug_mask);
+
 static unsigned int ath10k_cryptmode_param;
 static bool uart_print;
 static bool skip_otp;

drivers/net/wireless/ath/ath10k/debug.c

@@ -2664,7 +2664,7 @@ void ath10k_debug_unregister(struct ath10k *ar)
 #endif /* CONFIG_ATH10K_DEBUGFS */
 
 #ifdef CONFIG_ATH10K_DEBUG
-void ath10k_dbg(struct ath10k *ar, enum ath10k_debug_mask mask,
+void __ath10k_dbg(struct ath10k *ar, enum ath10k_debug_mask mask,
 		  const char *fmt, ...)
 {
 	struct va_format vaf;
@@ -2682,7 +2682,7 @@ void ath10k_dbg(struct ath10k *ar, enum ath10k_debug_mask mask,
 
 	va_end(args);
 }
-EXPORT_SYMBOL(ath10k_dbg);
+EXPORT_SYMBOL(__ath10k_dbg);
 
 void ath10k_dbg_dump(struct ath10k *ar,
 		     enum ath10k_debug_mask mask,
@@ -2695,7 +2695,7 @@ void ath10k_dbg_dump(struct ath10k *ar,
 
 	if (ath10k_debug_mask & mask) {
 		if (msg)
-			ath10k_dbg(ar, mask, "%s\n", msg);
+			__ath10k_dbg(ar, mask, "%s\n", msg);
 
 		for (ptr = buf; (ptr - buf) < len; ptr += 16) {
 			linebuflen = 0;

drivers/net/wireless/ath/ath10k/debug.h

@@ -240,7 +240,7 @@ void ath10k_sta_update_rx_tid_stats_ampdu(struct ath10k *ar,
 #endif /* CONFIG_MAC80211_DEBUGFS */
 
 #ifdef CONFIG_ATH10K_DEBUG
-__printf(3, 4) void ath10k_dbg(struct ath10k *ar,
+__printf(3, 4) void __ath10k_dbg(struct ath10k *ar,
 				 enum ath10k_debug_mask mask,
 				 const char *fmt, ...);
 void ath10k_dbg_dump(struct ath10k *ar,
@@ -249,7 +249,7 @@ void ath10k_dbg_dump(struct ath10k *ar,
 		     const void *buf, size_t len);
 #else /* CONFIG_ATH10K_DEBUG */
 
-static inline int ath10k_dbg(struct ath10k *ar,
+static inline int __ath10k_dbg(struct ath10k *ar,
 			       enum ath10k_debug_mask dbg_mask,
 			       const char *fmt, ...)
 {
@@ -263,4 +263,14 @@ static inline void ath10k_dbg_dump(struct ath10k *ar,
 {
 }
 #endif /* CONFIG_ATH10K_DEBUG */
+
+/* Avoid calling __ath10k_dbg() if debug_mask is not set and tracing
+ * disabled.
+ */
+#define ath10k_dbg(ar, dbg_mask, fmt, ...)			\
+do {								\
+	if ((ath10k_debug_mask & dbg_mask) ||			\
+	    trace_ath10k_log_dbg_enabled())			\
+		__ath10k_dbg(ar, dbg_mask, fmt, ##__VA_ARGS__); \
+} while (0)
 #endif /* _DEBUG_H_ */

drivers/net/wireless/ath/ath10k/trace.c

@@ -7,3 +7,4 @@
 
 #define CREATE_TRACE_POINTS
 #include "trace.h"
+EXPORT_SYMBOL(__tracepoint_ath10k_log_dbg);

drivers/net/wireless/ath/ath10k/trace.h

@@ -29,7 +29,11 @@ static inline u32 ath10k_frm_hdr_len(const void *buf, size_t len)
 #if !defined(CONFIG_ATH10K_TRACING)
 #undef TRACE_EVENT
 #define TRACE_EVENT(name, proto, ...) \
-static inline void trace_ ## name(proto) {}
+static inline void trace_ ## name(proto) {} \
+static inline bool trace_##name##_enabled(void) \
+{						\
+	return false;				\
+}
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(...)
 #undef DEFINE_EVENT