/*
 * Copyright (c) 2016 Intel Corporation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * @file
 * @brief Private nanokernel definitions
 *
 * This file contains private nanokernel structures definitions and various
 * other definitions for the Nios II processor architecture.
 *
 * This file is also included by assembly language files which must #define
 * _ASMLANGUAGE before including this header file.  Note that nanokernel
 * assembly source files obtains structure offset values via "absolute
 * symbols" in the offsets.o module.
 */

#ifndef _NANO_PRIVATE_H
#define _NANO_PRIVATE_H

#ifdef __cplusplus
extern "C" {
#endif

#include <toolchain.h>
#include <sections.h>
#include <arch/cpu.h>

#ifndef _ASMLANGUAGE
#include <nanokernel.h>            /* public nanokernel API */
#include <../../../kernel/nanokernel/include/nano_internal.h>
#include <stdint.h>
#include <misc/util.h>
#include <misc/dlist.h>
#endif

/* Bitmask definitions for the struct tcs->flags bit field */
#define FIBER          0x000
#define TASK           0x001 /* 1 = task, 0 = fiber   */

#define INT_ACTIVE     0x002 /* 1 = execution context is interrupt handler */
#define EXC_ACTIVE     0x004 /* 1 = executino context is exception handler */
#define USE_FP         0x010 /* 1 = thread uses floating point unit */
#define PREEMPTIBLE    0x020 /* 1 = preemptible thread */
#define ESSENTIAL      0x200 /* 1 = system thread that must not abort */
#define NO_METRICS     0x400 /* 1 = _Swap() not to update task metrics */

/* stacks */

#define STACK_ALIGN_SIZE 4

#define STACK_ROUND_UP(x) ROUND_UP(x, STACK_ALIGN_SIZE)
#define STACK_ROUND_DOWN(x) ROUND_DOWN(x, STACK_ALIGN_SIZE)

#ifndef _ASMLANGUAGE

struct irq_stack_frame {
	int stub;
};

typedef struct irq_stack_frame tISF;

struct callee_saved {
	int stub;
};

typedef struct callee_saved tCalleeSaved;

struct coop {
	int stub;
};

struct preempt {
	int stub;
};

struct tcs {
	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 */
	struct coop coopReg;
	struct preempt preempReg;
#ifdef CONFIG_ERRNO
	int errno_var;
#endif
#ifdef CONFIG_NANO_TIMEOUTS
	struct _nano_timeout nano_timeout;
#endif
#if defined(CONFIG_THREAD_MONITOR)
	struct __thread_entry *entry; /* thread entry and parameters description */
	struct tcs *next_thread; /* next item in list of ALL fiber+tasks */
#endif
};

struct s_NANO {
	struct tcs *fiber;    /* singly linked list of runnable fibers */
	struct tcs *task;     /* current task the nanokernel knows about */
	struct tcs *current;  /* currently scheduled thread (fiber or task) */

#if defined(CONFIG_NANO_TIMEOUTS) || defined(CONFIG_NANO_TIMERS)
	sys_dlist_t timeout_q;
	int32_t task_timeout;
#endif
#if defined(CONFIG_THREAD_MONITOR)
	struct tcs *threads; /* singly linked list of ALL fiber+tasks */
#endif
};

typedef struct s_NANO tNANO;
extern tNANO _nanokernel;


/* Arch-specific nanokernel APIs */
void nano_cpu_idle(void);
void nano_cpu_atomic_idle(unsigned int key);

static ALWAYS_INLINE void nanoArchInit(void)
{
	/* STUB */
}

static ALWAYS_INLINE void fiberRtnValueSet(struct tcs *fiber,
					   unsigned int value)
{
	ARG_UNUSED(fiber);
	ARG_UNUSED(value);
	/* STUB */
}

static inline void _IntLibInit(void)
{
	/* STUB ... possibly nothing to do here though */
}

FUNC_NORETURN void _NanoFatalErrorHandler(unsigned int reason,
					  const NANO_ESF *esf);


static ALWAYS_INLINE int _IS_IN_ISR(void)
{
	/* STUB */
	return 0;
}

#endif /* _ASMLANGUAGE */

#endif /* _NANO_PRIVATE_H */