kapi: introduce cpu::interrupt_handler

2 files changed, 53 insertions, 13 deletions

diff --git a/arch/x86_64/kapi/cpu.cpp b/arch/x86_64/kapi/cpu.cpp
index 8ca3847..b19ba21 100644
--- a/arch/x86_64/kapi/cpu.cpp
+++ b/arch/x86_64/kapi/cpu.cpp
@@ -4,11 +4,22 @@
 
 #include "arch/cpu/initialization.hpp"
 
+#include <kstd/print>
+#include <kstd/vector>
+
+#include <array>
 #include <atomic>
+#include <cstdint>
 
 namespace kapi::cpu
 {
 
+  namespace
+  {
+    constexpr auto irq_offset = 32uz;
+    auto constinit interrupt_handlers = std::array<kstd::vector<interrupt_handler *>, 256 - irq_offset>{};
+  }  // namespace
+
   auto init() -> void
   {
     auto static constinit is_initialized = std::atomic_flag{};
@@ -38,4 +49,42 @@ namespace kapi::cpu
     asm volatile("cli");
   }
 
+  auto register_interrupt_handler(std::uint32_t irq_number, interrupt_handler & handler) -> void
+  {
+    if (irq_number < irq_offset)
+    {
+      system::panic("[x86_64:CPU] IRQ number must be in range [32, 255].");
+    }
+
+    interrupt_handlers[irq_number - irq_offset].push_back(&handler);
+  }
+
+  auto unregister_interrupt_handler(std::uint32_t irq_number, [[maybe_unused]] interrupt_handler & handler) -> void
+  {
+    if (irq_number < irq_offset)
+    {
+      system::panic("[x86_64:CPU] IRQ number must be in range [32, 255].");
+    }
+
+    kstd::println("[x86_64:CPU] TODO: support erasure from vector.");
+  }
+
+  auto dispatch_interrupt(std::uint32_t irq_number) -> status
+  {
+    if (irq_number < irq_offset)
+    {
+      return status::unhandled;
+    }
+
+    for (auto handler : interrupt_handlers[irq_number - irq_offset])
+    {
+      if (handler && handler->handle_interrupt(irq_number) == status::handled)
+      {
+        return status::handled;
+      }
+    }
+
+    return status::unhandled;
+  }
+
 }  // namespace kapi::cpu
diff --git a/arch/x86_64/src/cpu/interrupts.cpp b/arch/x86_64/src/cpu/interrupts.cpp
index e578aa2..1f65336 100644
--- a/arch/x86_64/src/cpu/interrupts.cpp
+++ b/arch/x86_64/src/cpu/interrupts.cpp
@@ -46,7 +46,6 @@ namespace arch::cpu
     constexpr auto pic_master_irq_start = 0x20;
     constexpr auto pic_master_irq_end = pic_master_irq_start + 8;
     constexpr auto pic_slave_irq_start = pic_master_irq_end;
-    constexpr auto pic_slave_irq_end = pic_slave_irq_start + 8;
 
     constexpr auto to_exception_type(exception e)
     {
@@ -96,10 +95,8 @@ namespace arch::cpu
       }
     }
 
-    auto handle_legacy_interrupt(interrupt_frame * frame) -> void
+    auto acknowledge_pic_interrupt(interrupt_frame * frame) -> void
     {
-      kstd::println("[x86_64:SYS] Ignoring 8259 legacy interrupt {:#04x}", frame->interrupt.number);
-
       if (frame->interrupt.number >= pic_slave_irq_start)
       {
         pic_slave_control_port::write(pic_end_of_interrupt);
@@ -120,19 +117,13 @@ namespace arch::cpu
       {
         kstd::println(kstd::print_sink::stderr,
                       "[x86_64:CPU] Unhandled exception number {:#04x} received with code {:#04x}", number, code);
-        kapi::cpu::halt();
       }
-
-      if ((number >= pic_master_irq_start && number < pic_master_irq_end) ||
-          (number >= pic_slave_irq_start && number < pic_slave_irq_end))
+      else if (number >= pic_master_irq_start && kapi::cpu::dispatch_interrupt(number) == kapi::cpu::status::unhandled)
       {
-        handle_legacy_interrupt(frame);
-        return;
+        kstd::println(kstd::print_sink::stderr, "[x86_64:CPU] Unhandled interrupt {:#04x}", number);
       }
 
-      kstd::println(kstd::print_sink::stderr, "[x86_64:CPU] Unhandled interrupt {:#04x} received with code {:#04x}",
-                    frame->interrupt.number, frame->interrupt.error_code);
-      kapi::cpu::halt();
+      acknowledge_pic_interrupt(frame);
     }
   }