/* * 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