mbed-os/platform/mbed_critical.c

348 lines
9.2 KiB
C

/*
* Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* 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.
*/
/* Declare __STDC_LIMIT_MACROS so stdint.h defines UINT32_MAX when using C++ */
#define __STDC_LIMIT_MACROS
#include "hal/critical_section_api.h"
#include "cmsis.h"
#include "platform/mbed_assert.h"
#include "platform/mbed_critical.h"
#include "platform/mbed_toolchain.h"
// if __EXCLUSIVE_ACCESS rtx macro not defined, we need to get this via own-set architecture macros
#ifndef MBED_EXCLUSIVE_ACCESS
#ifndef __EXCLUSIVE_ACCESS
#if ((__ARM_ARCH_7M__ == 1U) || \
(__ARM_ARCH_7EM__ == 1U) || \
(__ARM_ARCH_8M_BASE__ == 1U) || \
(__ARM_ARCH_8M_MAIN__ == 1U)) || \
(__ARM_ARCH_7A__ == 1U)
#define MBED_EXCLUSIVE_ACCESS 1U
#elif (__ARM_ARCH_6M__ == 1U)
#define MBED_EXCLUSIVE_ACCESS 0U
#else
#error "Unknown architecture for exclusive access"
#endif
#else
#define MBED_EXCLUSIVE_ACCESS __EXCLUSIVE_ACCESS
#endif
#endif
static volatile uint32_t critical_section_reentrancy_counter = 0;
bool core_util_are_interrupts_enabled(void)
{
#if defined(__CORTEX_A9)
return ((__get_CPSR() & 0x80) == 0);
#else
return ((__get_PRIMASK() & 0x1) == 0);
#endif
}
bool core_util_is_isr_active(void)
{
#if defined(__CORTEX_A9)
switch(__get_CPSR() & 0x1FU) {
case CPSR_M_USR:
case CPSR_M_SYS:
return false;
case CPSR_M_SVC:
default:
return true;
}
#else
return (__get_IPSR() != 0U);
#endif
}
bool core_util_in_critical_section(void)
{
return hal_in_critical_section();
}
void core_util_critical_section_enter(void)
{
// FIXME
#ifdef FEATURE_UVISOR
#warning "core_util_critical_section_enter needs fixing to work from unprivileged code"
#else
// If the reentrancy counter overflows something has gone badly wrong.
MBED_ASSERT(critical_section_reentrancy_counter < UINT32_MAX);
#endif /* FEATURE_UVISOR */
hal_critical_section_enter();
++critical_section_reentrancy_counter;
}
void core_util_critical_section_exit(void)
{
// FIXME
#ifdef FEATURE_UVISOR
#warning "core_util_critical_section_exit needs fixing to work from unprivileged code"
#endif /* FEATURE_UVISOR */
// If critical_section_enter has not previously been called, do nothing
if (critical_section_reentrancy_counter == 0) {
return;
}
--critical_section_reentrancy_counter;
if (critical_section_reentrancy_counter == 0) {
hal_critical_section_exit();
}
}
#if MBED_EXCLUSIVE_ACCESS
/* Supress __ldrex and __strex deprecated warnings - "#3731-D: intrinsic is deprecated" */
#if defined (__CC_ARM)
#pragma diag_suppress 3731
#endif
bool core_util_atomic_cas_u8(volatile uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue)
{
do {
uint8_t currentValue = __LDREXB(ptr);
if (currentValue != *expectedCurrentValue) {
*expectedCurrentValue = currentValue;
__CLREX();
return false;
}
} while (__STREXB(desiredValue, ptr));
return true;
}
bool core_util_atomic_cas_u16(volatile uint16_t *ptr, uint16_t *expectedCurrentValue, uint16_t desiredValue)
{
do {
uint16_t currentValue = __LDREXH(ptr);
if (currentValue != *expectedCurrentValue) {
*expectedCurrentValue = currentValue;
__CLREX();
return false;
}
} while (__STREXH(desiredValue, ptr));
return true;
}
bool core_util_atomic_cas_u32(volatile uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue)
{
do {
uint32_t currentValue = __LDREXW(ptr);
if (currentValue != *expectedCurrentValue) {
*expectedCurrentValue = currentValue;
__CLREX();
return false;
}
} while (__STREXW(desiredValue, ptr));
return true;
}
uint8_t core_util_atomic_incr_u8(volatile uint8_t *valuePtr, uint8_t delta)
{
uint8_t newValue;
do {
newValue = __LDREXB(valuePtr) + delta;
} while (__STREXB(newValue, valuePtr));
return newValue;
}
uint16_t core_util_atomic_incr_u16(volatile uint16_t *valuePtr, uint16_t delta)
{
uint16_t newValue;
do {
newValue = __LDREXH(valuePtr) + delta;
} while (__STREXH(newValue, valuePtr));
return newValue;
}
uint32_t core_util_atomic_incr_u32(volatile uint32_t *valuePtr, uint32_t delta)
{
uint32_t newValue;
do {
newValue = __LDREXW(valuePtr) + delta;
} while (__STREXW(newValue, valuePtr));
return newValue;
}
uint8_t core_util_atomic_decr_u8(volatile uint8_t *valuePtr, uint8_t delta)
{
uint8_t newValue;
do {
newValue = __LDREXB(valuePtr) - delta;
} while (__STREXB(newValue, valuePtr));
return newValue;
}
uint16_t core_util_atomic_decr_u16(volatile uint16_t *valuePtr, uint16_t delta)
{
uint16_t newValue;
do {
newValue = __LDREXH(valuePtr) - delta;
} while (__STREXH(newValue, valuePtr));
return newValue;
}
uint32_t core_util_atomic_decr_u32(volatile uint32_t *valuePtr, uint32_t delta)
{
uint32_t newValue;
do {
newValue = __LDREXW(valuePtr) - delta;
} while (__STREXW(newValue, valuePtr));
return newValue;
}
#else
bool core_util_atomic_cas_u8(volatile uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue)
{
bool success;
uint8_t currentValue;
core_util_critical_section_enter();
currentValue = *ptr;
if (currentValue == *expectedCurrentValue) {
*ptr = desiredValue;
success = true;
} else {
*expectedCurrentValue = currentValue;
success = false;
}
core_util_critical_section_exit();
return success;
}
bool core_util_atomic_cas_u16(volatile uint16_t *ptr, uint16_t *expectedCurrentValue, uint16_t desiredValue)
{
bool success;
uint16_t currentValue;
core_util_critical_section_enter();
currentValue = *ptr;
if (currentValue == *expectedCurrentValue) {
*ptr = desiredValue;
success = true;
} else {
*expectedCurrentValue = currentValue;
success = false;
}
core_util_critical_section_exit();
return success;
}
bool core_util_atomic_cas_u32(volatile uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue)
{
bool success;
uint32_t currentValue;
core_util_critical_section_enter();
currentValue = *ptr;
if (currentValue == *expectedCurrentValue) {
*ptr = desiredValue;
success = true;
} else {
*expectedCurrentValue = currentValue;
success = false;
}
core_util_critical_section_exit();
return success;
}
uint8_t core_util_atomic_incr_u8(volatile uint8_t *valuePtr, uint8_t delta)
{
uint8_t newValue;
core_util_critical_section_enter();
newValue = *valuePtr + delta;
*valuePtr = newValue;
core_util_critical_section_exit();
return newValue;
}
uint16_t core_util_atomic_incr_u16(volatile uint16_t *valuePtr, uint16_t delta)
{
uint16_t newValue;
core_util_critical_section_enter();
newValue = *valuePtr + delta;
*valuePtr = newValue;
core_util_critical_section_exit();
return newValue;
}
uint32_t core_util_atomic_incr_u32(volatile uint32_t *valuePtr, uint32_t delta)
{
uint32_t newValue;
core_util_critical_section_enter();
newValue = *valuePtr + delta;
*valuePtr = newValue;
core_util_critical_section_exit();
return newValue;
}
uint8_t core_util_atomic_decr_u8(volatile uint8_t *valuePtr, uint8_t delta)
{
uint8_t newValue;
core_util_critical_section_enter();
newValue = *valuePtr - delta;
*valuePtr = newValue;
core_util_critical_section_exit();
return newValue;
}
uint16_t core_util_atomic_decr_u16(volatile uint16_t *valuePtr, uint16_t delta)
{
uint16_t newValue;
core_util_critical_section_enter();
newValue = *valuePtr - delta;
*valuePtr = newValue;
core_util_critical_section_exit();
return newValue;
}
uint32_t core_util_atomic_decr_u32(volatile uint32_t *valuePtr, uint32_t delta)
{
uint32_t newValue;
core_util_critical_section_enter();
newValue = *valuePtr - delta;
*valuePtr = newValue;
core_util_critical_section_exit();
return newValue;
}
#endif
bool core_util_atomic_cas_ptr(void * volatile *ptr, void **expectedCurrentValue, void *desiredValue) {
return core_util_atomic_cas_u32(
(volatile uint32_t *)ptr,
(uint32_t *)expectedCurrentValue,
(uint32_t)desiredValue);
}
void *core_util_atomic_incr_ptr(void * volatile *valuePtr, ptrdiff_t delta) {
return (void *)core_util_atomic_incr_u32((volatile uint32_t *)valuePtr, (uint32_t)delta);
}
void *core_util_atomic_decr_ptr(void * volatile *valuePtr, ptrdiff_t delta) {
return (void *)core_util_atomic_decr_u32((volatile uint32_t *)valuePtr, (uint32_t)delta);
}