metalsvm/arch/x86/include/asm/irqflags.h
Stefan Lankes 45313d47f2 add build environment for 64bit code
=> environment build 64bit kernel, but the kernel is not tested!
=> work in progess
2012-05-24 10:49:45 +02:00

97 lines
2.4 KiB
C

/*
* Copyright 2010 Stefan Lankes, Chair for Operating Systems,
* RWTH Aachen University
*
* 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.
*
* This file is part of MetalSVM.
*/
/**
* @author Stefan Lankes
* @file arch/x86/include/asm/irqflags.h
* @brief Functions related to IRQ configuration
*
* This file contains definitions of inline functions
* for enabling and disabling IRQ handling.
*/
#ifndef __ARCH_IRQFLAGS_H__
#define __ARCH_IRQFLAGS_H__
#ifdef __cplusplus
extern "C" {
#endif
/** @brief Disable IRQs
*
* This inline function just clears out the interrupt bit
*/
inline static void irq_disable(void) {
asm volatile("cli" ::: "memory");
}
/** @brief Disable IRQs (nested)
*
* Disable IRQs when unsure if IRQs were enabled at all.\n
* This function together with irq_nested_enable can be used
* in situations when interrupts shouldn't be activated if they
* were not activated before calling this function.
*
* @return The set of flags which have been set until now
*/
inline static uint32_t irq_nested_disable(void) {
size_t flags;
asm volatile("pushf; cli; pop %0": "=r"(flags) : : "memory");
if (flags & (1 << 9))
return 1;
return 0;
}
/** @brief Enable IRQs */
inline static void irq_enable(void) {
asm volatile("sti" ::: "memory");
}
/** @brief Enable IRQs (nested)
*
* If called after calling irq_nested_disable, this function will
* not activate IRQs if they were not active before.
*
* @param flags Flags to set. Could be the old ones you got from irq_nested_disable.
*/
inline static void irq_nested_enable(uint32_t flags) {
if (flags)
irq_enable();
}
/** @brief Determines, if the interrupt flags (IF) is ser
*
* @return
* - 1 interrupt flag is set
* - 0 interrupt flag is cleared
*/
inline static uint32_t is_irq_enabled(void)
{
size_t flags;
asm volatile("pushf; pop %0": "=r"(flags) : : "memory");
if (flags & (1 << 9))
return 1;
return 0;
}
#ifdef __cplusplus
}
#endif
#endif