[PATCH v3 2/5] firmware: arm_scmi: Add support for tracking statistics

[Luke Parkin <luke.parkin@arm.com>]

Add a new config option for statistic tracking in SCMI subsystem
Add an array and enum for tracking statistics
Add scmi_log_stats op/no-op function for incrementing statistics

Signed-off-by: Luke Parkin <luke.parkin@arm.com>
---
v2->v3
Switch to an enum & array method of storing statistics
v1->v2
Config option now depends on DEBUG_FS
Add scmi_log_stats rather than if(IS_ENABLED)
Move location of scmi_debug_stats in the scmi_info struct
---
 drivers/firmware/arm_scmi/Kconfig  | 11 +++++++++++
 drivers/firmware/arm_scmi/common.h |  9 +++++++++
 drivers/firmware/arm_scmi/driver.c |  6 ++++++
 3 files changed, 26 insertions(+)

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index aa5842be19b2..45e8e7df927e 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig
@@ -55,6 +55,17 @@ config ARM_SCMI_RAW_MODE_SUPPORT_COEX
 	  operate normally, thing which could make an SCMI test suite using the
 	  SCMI Raw mode support unreliable. If unsure, say N.
 
+config ARM_SCMI_DEBUG_STATISTICS
+	bool "Enable SCMI Raw mode statistic tracking"
+	select ARM_SCMI_NEED_DEBUGFS
+	depends on DEBUG_FS
+	help
+	  Enables statistic tracking for the SCMI subsystem.
+
+	  Enable this option to create a new debugfs directory which contains
+	  several useful statistics on various SCMI features. This can be useful
+	  for debugging and SCMI monitoring. If unsure, say N.
+
 config ARM_SCMI_HAVE_TRANSPORT
 	bool
 	help
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index b5ac25dbc1ca..157df695aeb1 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -301,6 +301,15 @@ extern const struct scmi_desc scmi_optee_desc;
 
 void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv);
 
+#ifdef CONFIG_ARM_SCMI_DEBUG_STATISTICS
+static inline void scmi_log_stats(atomic_t *arr, int stat)
+{
+	atomic_inc(&arr[stat]);
+}
+#else
+static inline void scmi_log_stats(atomic_t *arr, int stat) {}
+#endif
+
 enum scmi_bad_msg {
 	MSG_UNEXPECTED = -1,
 	MSG_INVALID = -2,
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 56a93d20bf23..6edec6ec912d 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -125,6 +125,10 @@ struct scmi_debug_info {
 	bool is_atomic;
 };
 
+enum debug_stat_counters {
+	LAST
+};
+
 /**
  * struct scmi_info - Structure representing a SCMI instance
  *
@@ -161,6 +165,7 @@ struct scmi_debug_info {
  *		bus
  * @devreq_mtx: A mutex to serialize device creation for this SCMI instance
  * @dbg: A pointer to debugfs related data (if any)
+ * @dbg_stats: An array of atomic_c's used for tracking statistics (if enabled)
  * @raw: An opaque reference handle used by SCMI Raw mode.
  */
 struct scmi_info {
@@ -187,6 +192,7 @@ struct scmi_info {
 	/* Serialize device creation process for this instance */
 	struct mutex devreq_mtx;
 	struct scmi_debug_info *dbg;
+	atomic_t dbg_stats[LAST];
 	void *raw;
 };
 
-- 
2.34.1