platform: ace: notifying about idle thread readiness

Informing the primary core that the Idle thread on secondary core is
ready. During the D3 exit flow thread is not initialize again, but
restored from previously saved context.

Signed-off-by: Tomasz Leman <tomasz.m.leman@intel.com>

Author: tmleman

src/platform/intel/ace/platform.c

@@ -23,6 +23,7 @@
 #include <ipc/info.h>
 #include <kernel/abi.h>
 #include <rtos/clk.h>
+#include <zephyr/pm/pm.h>
 
 #include <sof_versions.h>
 #include <stdint.h>
@@ -75,6 +76,23 @@ int platform_boot_complete(uint32_t boot_message)
 
 /* Value to be determined experimentaly */
 #define BASE_CPS_USAGE 10000
+
+extern void ace_mark_thread_as_ready(void);
+
+/* notifier called after every power state transition */
+static void notify_pm_state_exit(enum pm_state state)
+{
+	if (state == PM_STATE_SOFT_OFF)	{
+		if (!cpu_is_primary(arch_proc_id()))
+			ace_mark_thread_as_ready();
+	}
+}
+
+static struct pm_notifier pm_state_notifier = {
+	.state_entry = NULL,
+	.state_exit = notify_pm_state_exit,
+};
+
 /* Runs on the primary core only */
 int platform_init(struct sof *sof)
 {
@@ -102,6 +120,9 @@ int platform_init(struct sof *sof)
 	if (ret < 0)
 		return ret;
 
+	/* register power states entry / exit notifiers */
+	pm_notifier_register(&pm_state_notifier);
+
 	/* initialize the host IPC mechanisms */
 	trace_point(TRACE_BOOT_PLATFORM_IPC);
 	ipc_init(sof);

zephyr/lib/cpu.c

@@ -27,6 +27,11 @@ extern K_KERNEL_STACK_ARRAY_DEFINE(z_interrupt_stacks, CONFIG_MP_NUM_CPUS,
 static atomic_t start_flag;
 static atomic_t ready_flag;
 
+void ace_mark_thread_as_ready(void)
+{
+	atomic_set(&ready_flag, 1);
+}
+
 /* Zephyr kernel_internal.h interface */
 extern void smp_timer_init(void);