unified/arc: add unified kernel support for ARC arch

- the interrupt (both regular and fast) now does not do rescheduling
  if the current thread is a coop thread or if the scheduler is not locked

- the _nanokernel.flags cache of _current.flags is not used anymore
  (could be a source of bugs) and is not needed in the scheduling algo

- there is no 'task' field in the _nanokernel anymore: scheduling routines
  call _get_next_ready_thread instead

- the _nanokernel.fiber field is replaced by a more sophisticated
  ready_q, based on the microkernel's priority-bitmap-based one

- thread initialization initializes new fields in the tcs, and does not
  initialize obsolete ones

- nano_private includes nano_internal.h from the unified directory

- The FIBER, TASK and PREEMPTIBLE flags do not exist anymore: the thread
  priority drives the behaviour

- the tcs uses a dlist for queuing in both ready and wait queues instead
  of a custom singly-linked list

- other new fields in the tcs include a schedule-lock count, a
  back-pointer to init data (when the task is static) and a pointer to
  swap data, needed when a thread pending on _Swap() must be passed more
  then just one value (e.g. k_stack_pop() needs an error code and data)

- the 'fiber' and 'task' fields of _nanokernel are replaced with an O(1)
  ready queue (taken from the microkernel)

- fiberRtnValueSet() is aliased to _set_thread_return_value since it
  also operates on preempt threads now

- _set_thread_return_value_with_data() sets the swap_data field in
  addition to a return value from _Swap()

- convenience aliases are created for shorter names:

  - _current is defined as _nanokernel.current
  - _ready_q is defined as _nanokernel.ready_q

- _Swap() sets the threads's return code to -EAGAIN before swapping out
  to prevent timeouts to have to set it (solves hard issues in some
  kernel objects).

Change-Id: Ib9690173cbc36c36a9ec67e65590b40d758673de
Signed-off-by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com>

arch/arc/include/nano_private.h

@@ -40,8 +40,13 @@ extern "C" {
 #include <vector_table.h>
 
 #ifndef _ASMLANGUAGE
+#ifdef CONFIG_KERNEL_V2
+#include <kernel.h>
+#include <../../../kernel/unified/include/nano_internal.h>
+#else
 #include <nanokernel.h>            /* public nanokernel API */
 #include <../../../kernel/nanokernel/include/nano_internal.h>
+#endif
 #include <stdint.h>
 #include <misc/util.h>
 #include <misc/dlist.h>
@@ -134,13 +139,28 @@ typedef struct callee_saved tCalleeSaved;
 
 /* Bitmask definitions for the struct tcs->flags bit field */
 
+#ifdef CONFIG_KERNEL_V2
+#define K_STATIC  0x00000800
+
+#define K_READY              0x00000000    /* Thread is ready to run */
+#define K_TIMING             0x00001000    /* Thread is waiting on a timeout */
+#define K_PENDING            0x00002000    /* Thread is waiting on an object */
+#define K_PRESTART           0x00004000    /* Thread has not yet started */
+#define K_DEAD               0x00008000    /* Thread has terminated */
+#define K_SUSPENDED          0x00010000    /* Thread is suspended */
+#define K_DUMMY              0x00020000    /* Not a real thread */
+#define K_EXECUTION_MASK    (K_TIMING | K_PENDING | K_PRESTART | \
+			     K_DEAD | K_SUSPENDED | K_DUMMY)
+#else
 #define FIBER          0x000
 #define TASK           0x001 /* 1 = task, 0 = fiber   */
 
 #define INT_ACTIVE     0x002 /* 1 = executing context is interrupt handler */
 #define EXC_ACTIVE     0x004 /* 1 = executing context is exception handler */
-#define USE_FP         0x010 /* 1 = thread uses floating point unit */
 #define PREEMPTIBLE    0x020 /* 1 = preemptible thread */
+#endif
+
+#define USE_FP         0x010 /* 1 = thread uses floating point unit */
 #define ESSENTIAL      0x200 /* 1 = system thread that must not abort */
 #define NO_METRICS     0x400 /* 1 = _Swap() not to update task metrics */
 
@@ -162,15 +182,38 @@ typedef struct callee_saved tCalleeSaved;
 
 #ifndef _ASMLANGUAGE
 
+#ifdef CONFIG_KERNEL_V2
+/* 'struct tcs_base' must match the beginning of 'struct tcs' */
+struct tcs_base {
+	sys_dnode_t  k_q_node;
+	uint32_t     flags;
+	int          prio;
+	void        *swap_data;
+#ifdef CONFIG_NANO_TIMEOUTS
+	struct _timeout timeout;
+#endif
+};
+#endif
+
 struct tcs {
+#ifdef CONFIG_KERNEL_V2
+	sys_dnode_t k_q_node;   /* node object in any kernel queue */
+	uint32_t    flags;
+	int         prio;
+	void       *swap_data;
+#ifdef CONFIG_NANO_TIMEOUTS
+	struct _timeout timeout;
+#endif
+#else
 	struct tcs *link;         /* node in singly-linked list
 				   * _nanokernel.fibers
 				   */
 	uint32_t flags;           /* bitmask of flags above */
+	int prio;                 /* fiber priority, -1 for a task */
+#endif /* CONFIG_KERNEL_V2 */
 	uint32_t intlock_key;     /* interrupt key when relinquishing control */
 	int relinquish_cause;     /* one of the _CAUSE_xxxx definitions above */
 	unsigned int return_value;/* return value from _Swap */
-	int prio;                 /* fiber priority, -1 for a task */
 #ifdef CONFIG_THREAD_CUSTOM_DATA
 	void *custom_data;        /* available for custom use */
 #endif
@@ -180,7 +223,7 @@ struct tcs {
 	struct __thread_entry *entry; /* thread entry and parameters description */
 	struct tcs *next_thread;  /* next item in list of ALL fiber+tasks */
 #endif
-#ifdef CONFIG_NANO_TIMEOUTS
+#if !defined(CONFIG_KERNEL_V2) && defined(CONFIG_NANO_TIMEOUTS)
 	struct _nano_timeout nano_timeout;
 #endif
 #ifdef CONFIG_ERRNO
@@ -189,14 +232,29 @@ struct tcs {
 #ifdef CONFIG_ARC_STACK_CHECKING
 	uint32_t stack_top;
 #endif
-#ifdef CONFIG_MICROKERNEL
+#if !defined(CONFIG_KERNEL_V2) && defined(CONFIG_MICROKERNEL)
 	void *uk_task_ptr;
 #endif
+#ifdef CONFIG_KERNEL_V2
+	atomic_t sched_locked;
+	void *init_data;
+	void (*fn_abort)(void);
+#endif
 };
 
+#ifdef CONFIG_KERNEL_V2
+struct ready_q {
+	struct k_thread *cache;
+	uint32_t prio_bmap[1];
+	sys_dlist_t q[K_NUM_PRIORITIES];
+};
+#endif
+
 struct s_NANO {
+#if !defined(CONFIG_KERNEL_V2)
 	struct tcs *fiber;    /* singly linked list of runnable fibers */
 	struct tcs *task;     /* current task the nanokernel knows about */
+#endif
 	struct tcs *current;  /* currently scheduled thread (fiber or task) */
 
 #ifdef CONFIG_THREAD_MONITOR
@@ -224,6 +282,9 @@ struct s_NANO {
 	int32_t task_timeout;
 #endif
 #endif
+#ifdef CONFIG_KERNEL_V2
+	struct ready_q ready_q;
+#endif
 };
 
 typedef struct s_NANO tNANO;
@@ -255,13 +316,28 @@ static ALWAYS_INLINE void fiberRtnValueSet(struct tcs *fiber, unsigned int value
 	fiber->return_value = value;
 }
 
+#ifdef CONFIG_KERNEL_V2
+	#define _current _nanokernel.current
+	#define _ready_q _nanokernel.ready_q
+	#define _timeout_q _nanokernel.timeout_q
+	#define _set_thread_return_value fiberRtnValueSet
+static ALWAYS_INLINE void
+_set_thread_return_value_with_data(struct k_thread *thread, unsigned int value,
+				   void *data)
+{
+	_set_thread_return_value(thread, value);
+	thread->swap_data = data;
+}
+	#define _IDLE_THREAD_PRIO (CONFIG_NUM_PREEMPT_PRIORITIES)
+#endif /* CONFIG_KERNEL_V2 */
+
 /**
  *
  * @brief Indicates if kernel is handling interrupt
  *
  * @return 1 if interrupt handler is executed, 0 otherwise
  */
-static ALWAYS_INLINE int _IS_IN_ISR(void)
+static ALWAYS_INLINE int _is_in_isr(void)
 {
 	uint32_t act = _arc_v2_aux_reg_read(_ARC_V2_AUX_IRQ_ACT);
 #if CONFIG_IRQ_OFFLOAD
@@ -274,6 +350,8 @@ static ALWAYS_INLINE int _IS_IN_ISR(void)
 	return ((act & 0xffff) != 0);
 }
 
+#define _IS_IN_ISR _is_in_isr
+
 /**
  *
  * @bried Indicates the interrupt number of the highest priority