Handout

arch/ioapic.h

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+/*! \file
+ *  \brief \ref IOAPIC abstracts the access to the I/O \ref APIC
+ */
+
+#pragma once
+#include "../types.h"
+#include "core_interrupt.h"
+#include "ioapic_registers.h"
+
+/*! \brief Abstraction of the I/O APIC that is used for management of external
+ * interrupts.
+ *  \ingroup interrupts
+ *
+ *  The I/O APIC's Core component is the IO-redirection table. This table is
+ * used to configure a flexible mapping between the interrupt number and the
+ * external interruption. Entries within this table have a width of 64 bit. For
+ * convenience, the union \ref IOAPIC::RedirectionTableEntry should be used for
+ * modifying these tables (see file `ioapic_registers.h` for details).
+ */
+
+namespace IOAPIC {
+/*! \brief Initializes the I/O APIC.
+ *
+ *  This function will initialize the I/O APIC by initializing the
+ * IO-redirection table with sane default values. The default interrupt-vector
+ * number is chosen such that, in case the interrupt is issued, the panic
+ * handler is executed. In the beginning, all external interrupts are disabled
+ * within the I/O APIC. Apart from the redirection table, the `APICID` (read
+ * from the system description tables during boot) needs to be written to the
+ * `IOAPICID` register (see \ref APIC::getIOAPICID() )
+ *
+ *  \todo(12) Implement Function
+ */
+void init();
+
+/*! \brief Creates a mapping between an interrupt vector and an external
+ interrupt.
+ *
+ *  \param slot         Number of the slot (i.e., the external interrupt) to
+ configure.
+ *  \param vector       Number of the interrupt vector that will be issued for
+ the external interrupt.
+ *  \param trigger_mode Edge or level triggered interrupt signaling
+ (level-triggered interrupts required for the optional serial interface)
+ *  \param polarity     Polarity of the interrupt signaling (active high or
+ active low)
+ *
+ *  \todo(12) Implement Function
+ */
+void config(uint8_t slot, Core::Interrupt::Vector vector,
+            TriggerMode trigger_mode = TriggerMode::EDGE,
+            Polarity polarity = Polarity::HIGH);
+
+/*! \brief Enables the redirection of particular external interrupts to the
+ * CPU(s).
+ *
+ *  To fully enable interrupt handling, the interrupts must be enabled for every
+ * CPU (e.g., by calling
+ *  \ref Core::Interrupt::enable() in main).
+ *  \todo(12) Do that somewhere appropriate.
+ *
+ *  \param slot Number of the external interrupt that should be enabled.
+ *
+ *  \todo(12) Implement Function
+ */
+void allow(uint8_t slot);
+
+/*! \brief Selectively masks external interrupts by slot number.
+ *  \param slot Slot number of the interrupt to be disabled.
+ *
+ *  \todo(12) Implement Function
+ */
+void forbid(uint8_t slot);
+
+/*! \brief Check whether an external interrupt source is masked.
+ *  \param slot Slot number of the interrupt to be checked.
+ *  \return Returns `true` iff the interrupt is unmasked, `false` otherwise
+ *
+ *  \todo(12) Implement Function
+ */
+bool status(uint8_t slot);
+}  // namespace IOAPIC