/*
    ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS/RT is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @file sys.h
 * @brief System related macros and structures.
 * @addtogroup System
 * @{
 */

#ifndef _SYS_H_
#define _SYS_H_

/**
 * @brief Halts the system.
 * @details This function is invoked by the operating system when an
 * unrecoverable error is detected (as example because a programming error in
 * the application code that triggers an assertion while in debug mode).
 */
#define chSysHalt() port_halt()

/**
 * @brief Performs a context switch.
 *
 * @param otp the thread to be switched out
 * @param ntp the thread to be switched in
 */
#define chSysSwitchI(otp, ntp) port_switch(otp, ntp)

/**
 * @brief Raises the system interrupt priority mask to the maximum level.
 * @details All the maskable interrupt sources are disabled regardless their
 * hardware priority.
 *
 * @note The implementation is architecture dependent, it may just disable the
 *       interrupts or be exactly equivalent to @p chSysDisable().
 * @note Do not invoke this API from within a kernel lock.
 */
#define chSysDisable() port_disable()

/**
 * @brief Raises the system interrupt priority mask to system level.
 * @details The interrupt sources that should not be able to preempt the kernel
 * are disabled, interrupt sources with higher priority are still enabled.
 *
 * @note The implementation is architecture dependent, it may just disable the
 *       interrupts.
 * @note Do not invoke this API from within a kernel lock.
 * @note This API is no replacement for @p chSysLock(), the @p chSysLock()
 *       could do more than just disable the interrupts.
 */
#define chSysSuspend() port_suspend()

/**
 * @brief Lowers the system interrupt priority mask to user level.
 * @details All the interrupt sources are enabled.
 *
 * @note The implementation is architecture dependent, it may just enable the
 *       interrupts.
 * @note Do not invoke this API from within a kernel lock.
 * @note This API is no replacement for @p chSysUnlock(), the @p chSysUnlock()
 *       could do more than just enable the interrupts.
 */
#define chSysEnable() port_enable()

/**
 * @brief Enters the kernel lock mode.
 *
 * @note The use of kernel lock mode is not recommended in the user code, it is
 *       a better idea to use the semaphores or mutexes instead.
 * @see CH_USE_NESTED_LOCKS
 */
#if CH_USE_NESTED_LOCKS || defined(__DOXYGEN__)
#if CH_OPTIMIZE_SPEED || defined(__DOXYGEN__)
#define chSysLock() {                                                   \
  if (currp->p_locks++ == 0)                                            \
    port_lock();                                                        \
}
#endif /* CH_OPTIMIZE_SPEED */
#else /* !CH_USE_NESTED_LOCKS */
#define chSysLock() port_lock()
#endif /* !CH_USE_NESTED_LOCKS */

/**
 * @brief Leaves the kernel lock mode.
 *
 * @note The use of kernel lock mode is not recommended in the user code, it is
 *       a better idea to use the semaphores or mutexes instead.
 * @see CH_USE_NESTED_LOCKS
 */
#if CH_USE_NESTED_LOCKS || defined(__DOXYGEN__)
#if CH_OPTIMIZE_SPEED || defined(__DOXYGEN__)
#define chSysUnlock() {                                                 \
  if (--currp->p_locks == 0)                                            \
    port_unlock();                                                      \
}
#endif /* CH_OPTIMIZE_SPEED */
#else /* !CH_USE_NESTED_LOCKS */
#define chSysUnlock() port_unlock()
#endif /* !CH_USE_NESTED_LOCKS */

/**
 * @brief Enters the kernel lock mode from within an interrupt handler.
 *
 * @note This API may do nothing on some architectures, it is required because
 *       on ports that support preemptable interrupt handlers it is required to
 *       raise the interrupt mask to the same level of the system mutual
 *       exclusion zone.<br>
 *       It is good practice to invoke this API before invoking any I-class
 *       syscall from an interrupt handler.
 * @note This API must be invoked exclusively from interrupt handlers.
 */
#define chSysLockFromIsr() port_lock_from_isr()

/**
 * @brief Leaves the kernel lock mode from within an interrupt handler.
 *
 * @note This API may do nothing on some architectures, it is required because
 *       on ports that support preemptable interrupt handlers it is required to
 *       raise the interrupt mask to the same level of the system mutual
 *       exclusion zone.<br>
 *       It is good practice to invoke this API after invoking any I-class
 *       syscall from an interrupt handler.
 * @note This API must be invoked exclusively from interrupt handlers.
 */
#define chSysUnlockFromIsr() port_unlock_from_isr()

/**
 * @brief IRQ handler enter code.
 *
 * @note Usually IRQ handlers functions are also declared naked.
 * @note On some architectures this macro can be empty.
 */
#define CH_IRQ_PROLOGUE() PORT_IRQ_PROLOGUE()

/**
 * @brief IRQ handler exit code.
 *
 * @note Usually IRQ handlers function are also declared naked.
 * @note This macro usually performs the final reschedulation by using
 *       @p chSchRescRequiredI() and @p chSchDoRescheduleI().
 */
#define CH_IRQ_EPILOGUE() PORT_IRQ_EPILOGUE()

/**
 * @brief Standard IRQ handler declaration.
 *
 * @note @p id can be a function name or a vector number depending on the
 *       port implementation.
 */
#define CH_IRQ_HANDLER(id) PORT_IRQ_HANDLER(id)

#ifdef __cplusplus
extern "C" {
#endif
  void chSysInit(void);
  void chSysTimerHandlerI(void);
#if CH_USE_NESTED_LOCKS && !CH_OPTIMIZE_SPEED
  void chSysLock(void);
  void chSysUnlock(void);
#endif /* CH_USE_NESTED_LOCKS && !CH_OPTIMIZE_SPEED */
#ifdef __cplusplus
}
#endif

#endif /* _SYS_H_ */

/** @} */