tracing: Add sys_trace_idle_exit call

Add new tracing API which is called when core is exiting from idle.
Current implementation is using it to track CPU load. Implementation
in tracing_none is now weak so it can be used if given backend does
not support new API call.

When CONFIG_CPU_LOAD is enabled then sys_trace_idle also calls a
hook which stores the timing information when CPU entered idle.

Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>

Author: nordic-krch

include/zephyr/tracing/tracing.h

@@ -2718,6 +2718,12 @@
 
 #if defined(CONFIG_PERCEPIO_TRACERECORDER)
 #include "tracing_tracerecorder.h"
+
+/**
+ * @brief Called when the cpu exits the idle state
+ */
+void sys_trace_idle_exit(void);
+
 #else
 /**
  * @brief Called when entering an ISR
@@ -2738,6 +2744,12 @@ void sys_trace_isr_exit_to_scheduler(void);
  * @brief Called when the cpu enters the idle state
  */
 void sys_trace_idle(void);
+
+/**
+ * @brief Called when the cpu exits the idle state
+ */
+void sys_trace_idle_exit(void);
+
 #endif /* CONFIG_PERCEPIO_TRACERECORDER */
 
 /**

subsys/tracing/CMakeLists.txt

@@ -48,11 +48,9 @@ zephyr_sources_ifdef(
 
 endif()
 
-if(NOT CONFIG_PERCEPIO_TRACERECORDER AND NOT CONFIG_TRACING_CTF
-  AND NOT CONFIG_SEGGER_SYSTEMVIEW AND NOT CONFIG_TRACING_TEST
-  AND NOT CONFIG_TRACING_USER)
-  zephyr_sources(tracing_none.c)
-endif()
+zephyr_sources(
+  tracing_none.c
+  )
 
 zephyr_sources_ifdef(
   CONFIG_TRACING_OBJECT_TRACKING

subsys/tracing/ctf/ctf_top.c

@@ -13,6 +13,7 @@
 #include <zephyr/net/socket_poll.h>
 #include <zephyr/net/net_if.h>
 #include <zephyr/net/net_pkt.h>
+#include <zephyr/debug/cpu_load.h>
 
 static void _get_thread_name(struct k_thread *thread,
 			     ctf_bounded_string_t *name)
@@ -189,6 +190,16 @@ void sys_trace_isr_exit_to_scheduler(void)
 void sys_trace_idle(void)
 {
 	ctf_top_idle();
+	if (IS_ENABLED(CONFIG_CPU_LOAD)) {
+		cpu_load_on_enter_idle();
+	}
+}
+
+void sys_trace_idle_exit(void)
+{
+	if (IS_ENABLED(CONFIG_CPU_LOAD)) {
+		cpu_load_on_exit_idle();
+	}
 }
 
 /* Semaphore */

subsys/tracing/ctf/tracing_ctf.h

@@ -368,6 +368,7 @@ extern "C" {
 #define sys_trace_sys_init_exit(...)
 
 void sys_trace_idle(void);
+void sys_trace_idle_exit(void);
 void sys_trace_isr_enter(void);
 void sys_trace_isr_exit(void);
 

subsys/tracing/sysview/sysview.c

@@ -6,6 +6,7 @@
 #include <zephyr/kernel.h>
 #include <zephyr/kernel_structs.h>
 #include <zephyr/init.h>
+#include <zephyr/debug/cpu_load.h>
 #include <ksched.h>
 
 #include <SEGGER_SYSVIEW.h>
@@ -64,6 +65,17 @@ void sys_trace_isr_exit_to_scheduler(void)
 void sys_trace_idle(void)
 {
 	SEGGER_SYSVIEW_OnIdle();
+
+	if (IS_ENABLED(CONFIG_CPU_LOAD)) {
+		cpu_load_on_enter_idle();
+	}
+}
+
+void sys_trace_idle_exit(void)
+{
+	if (IS_ENABLED(CONFIG_CPU_LOAD)) {
+		cpu_load_on_exit_idle();
+	}
 }
 
 void sys_trace_named_event(const char *name, uint32_t arg0, uint32_t arg1)

subsys/tracing/sysview/tracing_sysview.h

@@ -655,6 +655,7 @@ void sys_trace_thread_info(struct k_thread *thread);
 	SEGGER_SYSVIEW_RecordEndCall(TID_SYSCALL)
 
 void sys_trace_idle(void);
+void sys_trace_idle_exit(void);
 
 void sys_trace_k_thread_create(struct k_thread *new_thread, size_t stack_size, int prio);
 void sys_trace_k_thread_user_mode_enter(k_thread_entry_t entry, void *p1, void *p2, void *p3);

subsys/tracing/test/tracing_string_format_test.c

@@ -204,6 +204,11 @@ void sys_trace_idle(void)
 	TRACING_STRING("%s\n", __func__);
 }
 
+void sys_trace_idle_exit(void)
+{
+	TRACING_STRING("%s\n", __func__);
+}
+
 void sys_trace_k_condvar_broadcast_enter(struct k_condvar *condvar)
 {
 	TRACING_STRING("%s: %p\n", __func__, condvar);

subsys/tracing/test/tracing_test.h

@@ -480,6 +480,7 @@
 #define sys_port_trace_pm_device_runtime_disable_exit(dev, ret)
 
 void sys_trace_idle(void);
+void sys_trace_idle_exit(void);
 void sys_trace_isr_enter(void);
 void sys_trace_isr_exit(void);
 

subsys/tracing/tracing_none.c

@@ -3,12 +3,25 @@
  *
  * SPDX-License-Identifier: Apache-2.0
  */
+#include <zephyr/tracing/tracing.h>
+#include <zephyr/debug/cpu_load.h>
 
+__weak void sys_trace_isr_enter(void) {}
 
-void sys_trace_isr_enter(void) {}
+__weak void sys_trace_isr_exit(void) {}
 
-void sys_trace_isr_exit(void) {}
+__weak void sys_trace_isr_exit_to_scheduler(void) {}
 
-void sys_trace_isr_exit_to_scheduler(void) {}
+__weak void sys_trace_idle(void)
+{
+	if (IS_ENABLED(CONFIG_CPU_LOAD)) {
+		cpu_load_on_enter_idle();
+	}
+}
 
-void sys_trace_idle(void) {}
+__weak void sys_trace_idle_exit(void)
+{
+	if (IS_ENABLED(CONFIG_CPU_LOAD)) {
+		cpu_load_on_exit_idle();
+	}
+}

subsys/tracing/user/tracing_user.c

@@ -7,6 +7,7 @@
 
 #include <tracing_user.h>
 #include <zephyr/kernel.h>
+#include <zephyr/debug/cpu_load.h>
 #include <zephyr/init.h>
 
 void __weak sys_trace_thread_create_user(struct k_thread *thread) {}
@@ -143,6 +144,17 @@ void sys_trace_isr_exit(void)
 void sys_trace_idle(void)
 {
 	sys_trace_idle_user();
+
+	if (IS_ENABLED(CONFIG_CPU_LOAD)) {
+		cpu_load_on_enter_idle();
+	}
+}
+
+void sys_trace_idle_exit(void)
+{
+	if (IS_ENABLED(CONFIG_CPU_LOAD)) {
+		cpu_load_on_exit_idle();
+	}
 }
 
 void sys_trace_sys_init_enter(const struct init_entry *entry, int level)