lib/cmsis_rtos_v1: Implement support for thread APIs

These APIs allow defining, creating and controlling of thread
related functionalities.

Signed-off-by: Rajavardhan Gundi <rajavardhan.gundi@intel.com>

include/cmsis_rtos_v1/cmsis_os.h

@@ -66,6 +66,7 @@
  
 #include <stdint.h>
 #include <stddef.h>
+#include <kernel.h>
  
 #ifdef  __cplusplus
 extern "C"
@@ -166,6 +167,8 @@ typedef struct os_thread_def  {
   osPriority             tpriority;    ///< initial thread priority
   uint32_t               instances;    ///< maximum number of instances of that thread function
   uint32_t               stacksize;    ///< stack size requirements in bytes; 0 is default stack size
+  void                  *stack_mem;    ///< pointer to array of stack memory
+  struct k_thread       *cm_thread;    ///< pointer to k_thread structure
 } osThreadDef_t;
  
 /// Timer Definition structure contains timer parameters.
@@ -276,8 +279,10 @@ uint32_t osKernelSysTick (void);
 extern const osThreadDef_t os_thread_def_##name
 #else                            // define the object
 #define osThreadDef(name, priority, instances, stacksz)  \
-const osThreadDef_t os_thread_def_##name = \
-{ (name), (priority), (instances), (stacksz)  }
+static K_THREAD_STACK_ARRAY_DEFINE(stacks_##name, instances, CONFIG_CMSIS_THREAD_MAX_STACK_SIZE); \
+static struct k_thread cm_thread_##name[instances]; \
+static osThreadDef_t os_thread_def_##name = \
+{ (name), (priority), (instances), (stacksz), (void *)(stacks_##name), (cm_thread_##name)}
 #endif
  
 /// Access a Thread definition.

lib/CMakeLists.txt

@@ -8,4 +8,5 @@ add_subdirectory_if_kconfig(ring_buffer)
 add_subdirectory_if_kconfig(base64)
 add_subdirectory(mempool)
 add_subdirectory_ifdef(CONFIG_PTHREAD_IPC          posix)
+add_subdirectory_ifdef(CONFIG_CMSIS_RTOS_V1        cmsis_rtos_v1)
 add_subdirectory(rbtree)

lib/Kconfig

@@ -31,4 +31,5 @@ config BASE64
 
 source "lib/posix/Kconfig"
 
+source "lib/cmsis_rtos_v1/Kconfig"
 endmenu

lib/cmsis_rtos_v1/CMakeLists.txt

@@ -0,0 +1,10 @@
+
+add_library(CMSIS INTERFACE)
+
+target_include_directories(CMSIS INTERFACE ${PROJECT_SOURCE_DIR}/include/cmsis_rtos_v1)
+
+zephyr_library()
+zephyr_library_sources_ifdef(CONFIG_CMSIS_RTOS_V1	cmsis_thread.c)
+
+zephyr_library_link_libraries(CMSIS)
+target_link_libraries(CMSIS INTERFACE zephyr_interface)

lib/cmsis_rtos_v1/Kconfig

@@ -0,0 +1,36 @@
+#
+# Copyright (c) 2018 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+config CMSIS_RTOS_V1
+	bool
+	prompt "CMSIS RTOS v1 API"
+	default n
+	help
+	  This enables CMSIS RTOS v1 API support. This is an OS-integration
+	  layer which allows applications using CMSIS RTOS APIs to build on
+	  Zephyr.
+
+if CMSIS_RTOS_V1
+config CMSIS_MAX_THREAD_COUNT
+	int
+	prompt "Maximum thread count in CMSIS RTOS application"
+	default 10
+	range 0 255
+	help
+	  Mention max number of threads in CMSIS RTOS compliant application.
+	  There's a limitation on the number of threads due to memory
+	  related constraints.
+
+config CMSIS_THREAD_MAX_STACK_SIZE
+	int
+	prompt "Max stack size threads can be allocated in CMSIS RTOS application"
+	default 512
+	help
+	  Mention max stack size threads can be allocated in CMSIS RTOS application.
+
+config NUM_PREEMPT_PRIORITIES
+	int
+	default 7
+endif

lib/cmsis_rtos_v1/cmsis_thread.c

@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2018 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <kernel_structs.h>
+#include <atomic.h>
+#include <cmsis_os.h>
+
+static inline int _is_thread_cmsis_inactive(struct k_thread *thread)
+{
+	u8_t state = thread->base.thread_state;
+
+	return state & (_THREAD_PRESTART | _THREAD_DEAD);
+}
+
+static inline s32_t zephyr_to_cmsis_priority(u32_t z_prio)
+{
+	return(osPriorityRealtime - z_prio);
+}
+
+static inline u32_t cmsis_to_zephyr_priority(s32_t c_prio)
+{
+	return(osPriorityRealtime - c_prio);
+}
+
+static void zephyr_thread_wrapper(void *arg1, void *arg2, void *arg3)
+{
+	void * (*fun_ptr)(void *) = arg3;
+
+	fun_ptr(arg1);
+}
+
+/**
+ * @brief Create a new thread.
+ */
+osThreadId osThreadCreate(const osThreadDef_t *thread_def, void *arg)
+{
+	struct k_thread *cm_thread;
+	u32_t prio;
+	k_tid_t tid;
+	u32_t stacksz;
+
+	k_thread_stack_t
+	   (*stk_ptr)[K_THREAD_STACK_LEN(CONFIG_CMSIS_THREAD_MAX_STACK_SIZE)];
+
+	__ASSERT(thread_def->stacksize >= 0 &&
+		 thread_def->stacksize <= CONFIG_CMSIS_THREAD_MAX_STACK_SIZE,
+		 "invalid stack size\n");
+
+	if (thread_def->instances == 0) {
+		return NULL;
+	}
+
+	if (_is_in_isr()) {
+		return NULL;
+	}
+
+	stacksz = thread_def->stacksize;
+	if (stacksz == 0) {
+		stacksz = CONFIG_CMSIS_THREAD_MAX_STACK_SIZE;
+	}
+
+	cm_thread = thread_def->cm_thread;
+	atomic_dec((atomic_t *)&thread_def->instances);
+	stk_ptr = thread_def->stack_mem;
+	prio = cmsis_to_zephyr_priority(thread_def->tpriority);
+
+	tid = k_thread_create(&cm_thread[thread_def->instances],
+			stk_ptr[thread_def->instances], stacksz,
+			(k_thread_entry_t)zephyr_thread_wrapper,
+			(void *)arg, NULL, thread_def->pthread,
+			prio, 0, K_NO_WAIT);
+
+	return ((osThreadId)tid);
+}
+
+/**
+ * @brief Return the thread ID of the current running thread.
+ */
+osThreadId osThreadGetId(void)
+{
+	if (_is_in_isr()) {
+		return NULL;
+	}
+
+	return (osThreadId)k_current_get();
+}
+
+/**
+ * @brief Get current priority of an active thread.
+ */
+osPriority osThreadGetPriority(osThreadId thread_id)
+{
+	k_tid_t thread = (k_tid_t)thread_id;
+	u32_t priority;
+
+	if (_is_in_isr()) {
+		return osPriorityError;
+	}
+
+	priority = k_thread_priority_get(thread);
+	return zephyr_to_cmsis_priority(priority);
+}
+
+/**
+ * @brief Change priority of an active thread.
+ */
+osStatus osThreadSetPriority(osThreadId thread_id, osPriority priority)
+{
+	if (thread_id == NULL) {
+		return osErrorParameter;
+	}
+
+	if (_is_in_isr()) {
+		return osErrorISR;
+	}
+
+	if (priority < osPriorityIdle || priority > osPriorityRealtime) {
+		return osErrorValue;
+	}
+
+	if (_is_thread_cmsis_inactive((k_tid_t)thread_id)) {
+		return osErrorResource;
+	}
+
+	k_thread_priority_set((k_tid_t)thread_id,
+				cmsis_to_zephyr_priority(priority));
+
+	return osOK;
+}
+
+/**
+ * @brief Terminate execution of a thread.
+ */
+osStatus osThreadTerminate(osThreadId thread_id)
+{
+	if (thread_id == NULL) {
+		return osErrorParameter;
+	}
+
+	if (_is_in_isr()) {
+		return osErrorISR;
+	}
+
+	if (_is_thread_cmsis_inactive((k_tid_t)thread_id)) {
+		return osErrorResource;
+	}
+
+	k_thread_abort((k_tid_t)thread_id);
+	return osOK;
+}
+
+/**
+ * @brief Pass control to next thread that is in READY state.
+ */
+osStatus osThreadYield(void)
+{
+	if (_is_in_isr()) {
+		return osErrorISR;
+	}
+
+	k_yield();
+	return osOK;
+}