schedule: add support for user-space LL scheduler

Add option to build SOF with support for running LL scheduler
in user-space. This commit adds initial support in the scheduler
and does not yet allow to run full SOF application using the new
scheduler configuration, but has enough functionality to run
scheduler level tests.

No functional change to default build configuration where LL
scheduler is run in kernel mode, or to platforms with no userspace
support.

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Author: kv2019i

src/include/sof/schedule/ll_schedule_domain.h

@@ -66,7 +66,11 @@ struct ll_schedule_domain_ops {
 struct ll_schedule_domain {
 	uint64_t next_tick;		/**< ticks just set for next run */
 	uint64_t new_target_tick;	/**< for the next set, used during the reschedule stage */
-	struct k_spinlock lock;		/**< standard lock */
+#ifdef CONFIG_SOF_USERSPACE_LL
+	struct k_mutex *lock;		/**< standard lock */
+#else
+	struct k_spinlock lock;         /**< standard lock */
+#endif
 	atomic_t total_num_tasks;	/**< total number of registered tasks */
 	atomic_t enabled_cores;		/**< number of enabled cores */
 	uint32_t ticks_per_ms;		/**< number of clock ticks per ms */
@@ -93,13 +97,26 @@ static inline struct ll_schedule_domain *dma_domain_get(void)
 	return sof_get()->platform_dma_domain;
 }
 
+#ifdef CONFIG_SOF_USERSPACE_LL
+struct task *zephyr_ll_task_alloc(void);
+struct k_heap *zephyr_ll_user_heap(void);
+void zephyr_ll_user_resources_init(void);
+#endif /* CONFIG_SOF_USERSPACE_LL */
+
 static inline struct ll_schedule_domain *domain_init
 				(int type, int clk, bool synchronous,
 				 const struct ll_schedule_domain_ops *ops)
 {
 	struct ll_schedule_domain *domain;
 
+#ifdef CONFIG_SOF_USERSPACE_LL
+	domain = sof_heap_alloc(zephyr_ll_user_heap(), SOF_MEM_FLAG_USER | SOF_MEM_FLAG_COHERENT,
+				sizeof(*domain), sizeof(void *));
+	if (domain)
+		memset(domain, 0, sizeof(*domain));
+#else
 	domain = rzalloc(SOF_MEM_FLAG_KERNEL | SOF_MEM_FLAG_COHERENT, sizeof(*domain));
+#endif
 	if (!domain)
 		return NULL;
 	domain->type = type;
@@ -116,7 +133,17 @@ static inline struct ll_schedule_domain *domain_init
 	domain->next_tick = UINT64_MAX;
 	domain->new_target_tick = UINT64_MAX;
 
+#ifdef CONFIG_SOF_USERSPACE_LL
+	/* Allocate mutex dynamically for userspace access */
+	domain->lock = k_object_alloc(K_OBJ_MUTEX);
+	if (!domain->lock) {
+		sof_heap_free(zephyr_ll_user_heap(), domain);
+		return NULL;
+	}
+	k_mutex_init(domain->lock);
+#else
 	k_spinlock_init(&domain->lock);
+#endif
 	atomic_init(&domain->total_num_tasks, 0);
 	atomic_init(&domain->enabled_cores, 0);
 
@@ -246,7 +273,11 @@ struct ll_schedule_domain *zephyr_dma_domain_init(struct dma *dma_array,
 struct ll_schedule_domain *zephyr_ll_domain(void);
 struct ll_schedule_domain *zephyr_domain_init(int clk);
 #define timer_domain_init(timer, clk) zephyr_domain_init(clk)
-#endif
+#ifdef CONFIG_SOF_USERSPACE_LL
+struct k_thread *zephyr_domain_thread_tid(struct ll_schedule_domain *domain);
+struct k_mem_domain *zephyr_ll_mem_domain(void);
+#endif /* CONFIG_SOF_USERSPACE_LL */
+#endif /* __ZEPHYR__ */
 
 struct ll_schedule_domain *dma_multi_chan_domain_init(struct dma *dma_array,
 						      uint32_t num_dma, int clk,

src/init/init.c

@@ -218,6 +218,10 @@ __cold static int primary_core_init(int argc, char *argv[], struct sof *sof)
 	io_perf_monitor_init();
 #endif
 
+#if CONFIG_SOF_USERSPACE_LL
+	zephyr_ll_user_resources_init();
+#endif
+
 	/* init the platform */
 	if (platform_init(sof) < 0)
 		sof_panic(SOF_IPC_PANIC_PLATFORM);

src/schedule/CMakeLists.txt

@@ -54,4 +54,8 @@ zephyr_library_sources_ifdef(CONFIG_ZEPHYR_TWB_SCHEDULER
 	zephyr_twb_schedule.c
 )
 
+zephyr_library_sources_ifdef(CONFIG_SOF_USERSPACE_LL
+	zephyr_ll_user.c
+)
+
 endif()