Enrico Fraccaroli
53 lines
1.6 KiB
C
53 lines
1.6 KiB
C
/// @file irqflags.h
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/// @brief
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/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
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/// See LICENSE.md for details.
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#pragma once
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#include "proc_access.h"
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#include "stddef.h"
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#include "stdint.h"
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/// @brief Enable IRQs (nested).
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/// @details If called after calling irq_disable, this function will not
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/// activate IRQs if they were not active before.
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/// @param flags the flags to control this behaviour.
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inline static void irq_enable(uint8_t flags)
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{
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if (flags) {
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sti();
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}
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}
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/// @brief Disable IRQs (nested).
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/// @details Disable IRQs when unsure if IRQs were enabled at all. This function
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/// together with irq_enable can be used in situations when interrupts
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/// shouldn't be activated if they were not activated before calling this
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/// function.
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/// @return 1 if the IRQ is enable for the CPU.
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inline static uint8_t irq_disable()
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{
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size_t flags;
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// We are pushing the entire contents of the EFLAGS register onto the stack,
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// clearing the interrupt line, and with the pop, getting the current status
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// of the flags.
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__asm__ __volatile__("pushf; cli; pop %0;"
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: "=r"(flags)
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:
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: "memory");
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return flags & (1 << 9);
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}
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/// @brief Determines, if the interrupt flags (IF) is set.
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/// @return 1 if the IRQ is enable for the CPU.
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inline static uint8_t is_irq_enabled()
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{
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size_t flags;
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__asm__ __volatile__("pushf; pop %0;"
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: "=r"(flags)
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:
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: "memory");
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return flags & (1 << 9);
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}
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