[PATCH v4 2/5] firmware: arm_scmi: Add support for tracking metrics

[Luke Parkin]

Add a new optional config option for tracking, configurable
	at build.
Add methods for counting key metrics

Signed-off-by: Luke Parkin <luke.parkin at arm.com>
---
v3->v4
Rename to counters rather than statistic tracking
Move enum tracker to common.h
Move stats array into debug
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 | 13 +++++++++++++
 drivers/firmware/arm_scmi/driver.c |  2 ++
 3 files changed, 26 insertions(+)

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index aa5842be19b2..b3ccd565b986 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_COUNTERS
+	bool "Enable SCMI debug tracking"
+	select ARM_SCMI_NEED_DEBUGFS
+	depends on DEBUG_FS
+	help
+	  Enables debug tracking for the SCMI subsystem.
+
+	  Enable this option to create a new debugfs directory which contains
+	  several useful debug counters. This can be helpful 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..8f80bf0ddddd 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -301,6 +301,19 @@ extern const struct scmi_desc scmi_optee_desc;
 
 void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv);
 
+enum debug_counters {
+	SCMI_DEBUG_COUNTERS_LAST
+};
+
+#ifdef CONFIG_ARM_SCMI_DEBUG_COUNTERS
+static inline void scmi_inc_count(atomic_t *arr, int stat)
+{
+	atomic_inc(&arr[stat]);
+}
+#else
+static inline void scmi_inc_count(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..958b2ac92050 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -117,12 +117,14 @@ struct scmi_protocol_instance {
  * @name: Name of this SCMI instance
  * @type: Type of this SCMI instance
  * @is_atomic: Flag to state if the transport of this instance is atomic
+ * @counters: An array of atomic_c's used for tracking statistics (if enabled)
  */
 struct scmi_debug_info {
 	struct dentry *top_dentry;
 	const char *name;
 	const char *type;
 	bool is_atomic;
+	atomic_t counters[SCMI_DEBUG_COUNTERS_LAST];
 };
 
 /**
-- 
2.34.1