x86_64/cpu: fixup 8259 interrupt handling

We now mask the timer interrupt and ensure we are informing the PIC
about us having handled the interrupt.

3 files changed, 28 insertions, 7 deletions

diff --git a/arch/x86_64/include/arch/cpu/legacy_pic.hpp b/arch/x86_64/include/arch/cpu/legacy_pic.hpp
new file mode 100644
index 0000000..9f53d86
--- /dev/null
+++ b/arch/x86_64/include/arch/cpu/legacy_pic.hpp
@@ -0,0 +1,19 @@
+#ifndef TEACHOS_X86_64_CPU_LEGACY_PIC_HPP
+#define TEACHOS_X86_64_CPU_LEGACY_PIC_HPP
+
+#include "arch/device_io/port_io.hpp"
+
+#include <cstdint>
+
+namespace arch::cpu
+{
+  using pic_master_control_port = io::port<0x20, std::uint8_t, io::port_read, io::port_write>;
+  using pic_master_data_port = io::port<0x21, std::uint8_t, io::port_read, io::port_write>;
+  using pic_slave_control_port = io::port<0xa0, std::uint8_t, io::port_read, io::port_write>;
+  using pic_slave_data_port = io::port<0xa1, std::uint8_t, io::port_read, io::port_write>;
+
+  constexpr auto pic_end_of_interrupt = std::uint8_t{0x20};
+
+}  // namespace arch::cpu
+
+#endif
\ No newline at end of file
diff --git a/arch/x86_64/src/cpu/initialization.cpp b/arch/x86_64/src/cpu/initialization.cpp
index 5f4703d..878fa07 100644
--- a/arch/x86_64/src/cpu/initialization.cpp
+++ b/arch/x86_64/src/cpu/initialization.cpp
@@ -2,9 +2,9 @@
 
 #include "arch/cpu/global_descriptor_table.hpp"
 #include "arch/cpu/interrupts.hpp"
+#include "arch/cpu/legacy_pic.hpp"
 #include "arch/cpu/segment_descriptor.hpp"
 #include "arch/cpu/task_state_segment.hpp"
-#include "arch/device_io/port_io.hpp"
 
 #include <kstd/print>
 
@@ -133,18 +133,13 @@ namespace arch::cpu
 
   auto initialize_legacy_interrupts() -> void
   {
-    using pic_master_control_port = io::port<0x20, std::uint8_t, io::port_read, io::port_write>;
-    using pic_master_data_port = io::port<0x21, std::uint8_t, io::port_read, io::port_write>;
-    using pic_slave_control_port = io::port<0xa0, std::uint8_t, io::port_read, io::port_write>;
-    using pic_slave_data_port = io::port<0xa1, std::uint8_t, io::port_read, io::port_write>;
-
     constexpr auto pic_init_command = std::uint8_t{0x11};
     constexpr auto pic_master_offset = std::uint8_t{0x20};
     constexpr auto pic_slave_offset = std::uint8_t{0x28};
     constexpr auto pic_cascade_address = std::uint8_t{0x04};
     constexpr auto pic_cascade_slave_identity = std::uint8_t{0x02};
     constexpr auto pic_use_8086_mode = std::uint8_t{0x01};
-    constexpr auto pic_master_mask = std::uint8_t{0x00};
+    constexpr auto pic_master_mask = std::uint8_t{0x01};
     constexpr auto pic_slave_mask = std::uint8_t{0x00};
 
     pic_master_control_port::write(pic_init_command);
@@ -161,6 +156,9 @@ namespace arch::cpu
 
     pic_master_data_port::write(pic_master_mask);
     pic_slave_data_port::write(pic_slave_mask);
+
+    pic_master_data_port::write(pic_master_mask);
+    pic_slave_data_port::write(pic_slave_mask);
   }
 
 }  // namespace arch::cpu
diff --git a/arch/x86_64/src/cpu/interrupts.cpp b/arch/x86_64/src/cpu/interrupts.cpp
index 466389d..048c461 100644
--- a/arch/x86_64/src/cpu/interrupts.cpp
+++ b/arch/x86_64/src/cpu/interrupts.cpp
@@ -2,6 +2,7 @@
 
 #include "kapi/cpu.hpp"
 
+#include "arch/cpu/legacy_pic.hpp"
 #include "arch/cpu/segment_selector.hpp"
 
 #include <kstd/print>
@@ -42,6 +43,9 @@ namespace arch::cpu
     auto handle_legacy_interrupt(interrupt_frame * frame) -> void
     {
       kstd::println("[x86_64:SYS] Ignoring 8259 legacy interrupt {:#04x}", frame->interrupt.number);
+
+      pic_master_control_port::write(pic_end_of_interrupt);
+      pic_slave_control_port::write(pic_end_of_interrupt);
     }
   }  // namespace