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/** @defgroup CM3_cortex_defines Cortex Core Defines
*
* @brief <b>libopencm3 Defined Constants and Types for the Cortex Core </b>
*
* @ingroup CM3_defines
*
* @version 1.0.0
*
* LGPL License Terms @ref lgpl_license
*/
/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2013 Ben Gamari <bgamari@gmail.com>
* Copyright (C) 2013 Frantisek Burian <BuFran@seznam.cz>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef LIBOPENCM3_CORTEX_H
#define LIBOPENCM3_CORTEX_H
/**@{*/
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Enable interrupts
*
* Disable the interrupt mask and enable interrupts globally
*/
static inline void cm_enable_interrupts(void)
{
__asm__("CPSIE I\n");
}
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Disable interrupts
*
* Mask all interrupts globally
*/
static inline void cm_disable_interrupts(void)
{
__asm__("CPSID I\n");
}
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Enable faults
*
* Disable the HardFault mask and enable fault interrupt globally
*/
static inline void cm_enable_faults(void)
{
__asm__("CPSIE F\n");
}
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Disable faults
*
* Mask the HardFault interrupt globally
*/
static inline void cm_disable_faults(void)
{
__asm__("CPSID F\n");
}
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Check if interrupts are masked
*
* Checks, if interrupts are masked (disabled).
*
* @returns true, if interrupts are disabled.
*/
__attribute__((always_inline))
static inline bool cm_is_masked_interrupts(void)
{
register uint32_t result;
__asm__ ("MRS %0, PRIMASK" : "=r" (result));
return result;
}
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Check if Fault interrupt is masked
*
* Checks, if HardFault interrupt is masked (disabled).
*
* @returns bool true, if HardFault interrupt is disabled.
*/
__attribute__((always_inline))
static inline bool cm_is_masked_faults(void)
{
register uint32_t result;
__asm__ ("MRS %0, FAULTMASK" : "=r" (result));
return result;
}
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Mask interrupts
*
* This function switches the mask of the interrupts. If mask is true, the
* interrupts will be disabled. The result of this function can be used for
* restoring previous state of the mask.
*
* @param[in] mask bool New state of the interrupt mask
* @returns bool old state of the interrupt mask
*/
__attribute__((always_inline))
static inline bool cm_mask_interrupts(bool mask)
{
register bool old;
__asm__ __volatile__("MRS %0, PRIMASK" : "=r" (old));
__asm__ __volatile__("" : : : "memory");
__asm__ __volatile__("MSR PRIMASK, %0" : : "r" (mask));
return old;
}
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Mask HardFault interrupt
*
* This function switches the mask of the HardFault interrupt. If mask is true,
* the HardFault interrupt will be disabled. The result of this function can be
* used for restoring previous state of the mask.
*
* @param[in] mask bool New state of the HardFault interrupt mask
* @returns bool old state of the HardFault interrupt mask
*/
__attribute__((always_inline))
static inline bool cm_mask_faults(bool mask)
{
register bool old;
__asm__ __volatile__ ("MRS %0, FAULTMASK" : "=r" (old));
__asm__ __volatile__ ("" : : : "memory");
__asm__ __volatile__ ("MSR FAULTMASK, %0" : : "r" (mask));
return old;
}
/**@}*/
/*===========================================================================*/
/** @defgroup CM3_cortex_atomic_defines Cortex Core Atomic support Defines
*
* @brief Atomic operation support
*
* @ingroup CM3_cortex_defines
*/
/**@{*/
#if !defined(__DOXYGEN__)
/* Do not populate this definition outside */
static inline bool __cm_atomic_set(bool *val)
{
return cm_mask_interrupts(*val);
}
#define __CM_SAVER(state) \
__val = state, \
__save __attribute__((__cleanup__(__cm_atomic_set))) = \
__cm_atomic_set(&__val)
#endif /* !defined(__DOXYGEN) */
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Atomic Declare block
*
* This macro disables interrupts for the next command or block of code. The
* interrupt mask is automatically restored after exit of the boundary of the
* code block. Therefore restore of interrupt is done automatically after call
* of return or goto control sentence jumping outside of the block.
*
* @warning The usage of sentences break or continue is prohibited in the block
* due to implementation of this macro!
*
* @note It is safe to use this block inside normal code and in interrupt
* routine.
*
* @example 1: Basic usage of atomic block
*
* @code
* uint64_t value; // This value is used somewhere in interrupt
*
* ...
*
* CM_ATOMIC_BLOCK() { // interrupts are masked in this block
* value = value * 1024 + 651; // access value as atomic
* } // interrupts is restored automatically
* @endcode
*
* @example 2: Use of return inside block:
*
* @code
* uint64_t value; // This value is used somewhere in interrupt
*
* ...
*
* uint64_t allocval(void)
* {
* CM_ATOMIC_BLOCK() { // interrupts are masked in this block
* value = value * 1024 + 651; // do long atomic operation
* return value; // interrupts is restored automatically
* }
* }
* @endcode
*/
#if defined(__DOXYGEN__)
#define CM_ATOMIC_BLOCK()
#else /* defined(__DOXYGEN__) */
#define CM_ATOMIC_BLOCK() \
for (bool ___CM_SAVER(true), __my = true; __my; __my = false)
#endif /* defined(__DOXYGEN__) */
/*---------------------------------------------------------------------------*/
/** @brief Cortex M Atomic Declare context
*
* This macro disables interrupts in the current block of code from the place
* where it is defined to the end of the block. The interrupt mask is
* automatically restored after exit of the boundary of the code block.
* Therefore restore of interrupt is done automatically after call of return,
* continue, break, or goto control sentence jumping outside of the block.
*
* @note This function is intended for use in for- cycles to enable the use of
* break and contine sentences inside the block, and for securing the atomic
* reader-like functions.
*
* @note It is safe to use this block inside normal code and in interrupt
* routine.
*
* @example 1: Basic usage of atomic context
*
* @code
* uint64_t value; // This value is used somewhere in interrupt
*
* ...
*
* for (int i=0;i < 100; i++) {
* CM_ATOMIC_CONTEXT(); // interrupts are masked in this block
* value += 100; // access value as atomic
* if ((value % 16) == 0) {
* break; // restore interrupts and break cycle
* }
* } // interrupts is restored automatically
* @endcode
*
* @example 2: Usage of atomic context inside atomic reader fcn.
*
* @code
* uint64_t value; // This value is used somewhere in interrupt
*
* ...
*
* uint64_t getnextval(void)
* {
* CM_ATOMIC_CONTEXT(); // interrupts are masked in this block
* value = value + 3; // do long atomic operation
* return value; // interrupts is restored automatically
* }
* @endcode
*/
#if defined(__DOXYGEN__)
#define CM_ATOMIC_CONTEXT()
#else /* defined(__DOXYGEN__) */
#define CM_ATOMIC_CONTEXT() bool __CM_SAVER(true)
#endif /* defined(__DOXYGEN__) */
/**@}*/
#endif
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