kapi/cpu: simplify exception handling

7 files changed, 28 insertions, 101 deletions

diff --git a/arch/x86_64/src/cpu/interrupts.cpp b/arch/x86_64/src/cpu/interrupts.cpp
index 4e52d71..9ee3ce8 100644
--- a/arch/x86_64/src/cpu/interrupts.cpp
+++ b/arch/x86_64/src/cpu/interrupts.cpp
@@ -108,11 +108,10 @@ namespace arch::cpu
           auto write = (frame->interrupt.error_code & 0x2) != 0;
           auto user = (frame->interrupt.error_code & 0x4) != 0;
 
-          return kapi::cpu::get_exception_handler().handle(
-              {type, instruction_pointer, fault_address, present, write, user});
+          return kapi::cpu::dispatch({type, instruction_pointer, fault_address, present, write, user});
         }
         default:
-          return kapi::cpu::get_exception_handler().handle({type, instruction_pointer});
+          return kapi::cpu::dispatch({type, instruction_pointer});
       }
     }
 
diff --git a/kapi/include/kapi/cpu/exception.hpp b/kapi/include/kapi/cpu/exception.hpp
index 00b02e7..d6e8511 100644
--- a/kapi/include/kapi/cpu/exception.hpp
+++ b/kapi/include/kapi/cpu/exception.hpp
@@ -31,7 +31,7 @@ namespace kapi::cpu
       memory_access_fault,
       //! An invalid instruction was present in the instruction stream.
       illegal_instruction,
-      //! The precoditions for the execution of an instruction were not met.
+      //! The preconditions for the execution of an instruction were not met.
       privilege_violation,
       //! An arithmetic error occurred.
       arithmetic_error,
@@ -60,27 +60,12 @@ namespace kapi::cpu
     bool is_user_mode{};
   };
 
-  //! The abstract interface for exception handlers.
-  //!
-  //! The kernel must define an exception handler to be used during execution.
-  struct exception_handler
-  {
-    virtual ~exception_handler() = default;
-
-    //! Handle an exception.
-    //!
-    //! @param context The exception context.
-    //! @return Whether the exception was handled.
-    virtual auto handle(exception const & context) -> bool = 0;
-  };
-
-  //! @qualifier kernel-defined
-  //! Get the currently active exception handler.
-  auto get_exception_handler() -> exception_handler &;
-
   //! @qualifier kernel-defined
-  //! Set the exception handler.
-  auto set_exception_handler(exception_handler & handler) -> void;
+  //! Dispatch an exception to the appropriate handler.
+  //!
+  //! @param context The exception context.
+  //! @return Whether the exception was handled.
+  auto dispatch(exception const & context) -> bool;
 
 }  // namespace kapi::cpu
 
diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index d9a5c75..9b1e2ad 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -11,7 +11,6 @@ add_executable("kernel"
     "kstd/print.cpp"
 
     # Kernel Implementation
-    "src/cpu.cpp"
     "src/main.cpp"
     "src/memory/bitmap_allocator.cpp"
     "src/memory/block_list_allocator.cpp"
diff --git a/kernel/include/kernel/cpu.hpp b/kernel/include/kernel/cpu.hpp
deleted file mode 100644
index d4e1ced..0000000
--- a/kernel/include/kernel/cpu.hpp
+++ /dev/null
@@ -1,14 +0,0 @@
-#ifndef TEACHOS_KERNEL_CPU_HPP
-#define TEACHOS_KERNEL_CPU_HPP
-
-namespace kernel::cpu
-{
-
-  //! Initialize the kernel heap.
-  auto init() -> void;
-
-  //!
-
-}  // namespace kernel::cpu
-
-#endif
\ No newline at end of file
diff --git a/kernel/kapi/cpu.cpp b/kernel/kapi/cpu.cpp
index 2089098..13de584 100644
--- a/kernel/kapi/cpu.cpp
+++ b/kernel/kapi/cpu.cpp
@@ -1,30 +1,35 @@
 #include "kapi/cpu.hpp"
 
+#include "kapi/system.hpp"
+
+#include <kstd/print>
+
 namespace kapi::cpu
 {
 
   namespace
   {
-    struct null_exception_handler : exception_handler
+    auto handle_page_fault(kapi::cpu::exception const & context) -> bool
     {
-      auto handle(exception const &) -> bool override
-      {
-        return false;
-      }
-    } static constinit default_exception_handler;
-
-    exception_handler * current_handler = &default_exception_handler;
+      kstd::println(kstd::print_sink::stderr, "\tFault address: {:#018x}", context.access_address);
+      kstd::println(kstd::print_sink::stderr, "\tPresent: {}", context.is_present);
+      kstd::println(kstd::print_sink::stderr, "\tWrite: {}", context.is_write_access);
+      kstd::println(kstd::print_sink::stderr, "\tUser: {}", context.is_user_mode);
 
+      kapi::system::panic("Halting the system due to an unrecoverable page fault.");
+    }
   }  // namespace
 
-  auto get_exception_handler() -> exception_handler &
+  auto dispatch(exception const & context) -> bool
   {
-    return *current_handler;
-  }
-
-  auto set_exception_handler(exception_handler & handler) -> void
-  {
-    current_handler = &handler;
+    kstd::println(kstd::print_sink::stderr, "[OS:CPU] {} @ {:#018x}", context.type, context.instruction_pointer);
+    switch (context.type)
+    {
+      case kapi::cpu::exception::type::page_fault:
+        return handle_page_fault(context);
+      default:
+        return false;
+    }
   }
 
 }  // namespace kapi::cpu
\ No newline at end of file
diff --git a/kernel/src/cpu.cpp b/kernel/src/cpu.cpp
deleted file mode 100644
index 11b6551..0000000
--- a/kernel/src/cpu.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-#include "kernel/cpu.hpp"
-
-#include "kapi/cpu.hpp"
-#include "kapi/system.hpp"
-
-#include <kstd/print>
-
-namespace kernel::cpu
-{
-
-  namespace
-  {
-    struct exception_handler : kapi::cpu::exception_handler
-    {
-      auto handle(kapi::cpu::exception const & context) -> bool override
-      {
-        kstd::println(kstd::print_sink::stderr, "[OS:CPU] {} @ {:#018x}", context.type, context.instruction_pointer);
-        switch (context.type)
-        {
-          case kapi::cpu::exception::type::page_fault:
-            return handle_page_fault(context);
-          default:
-            return false;
-        }
-      }
-
-    private:
-      auto handle_page_fault(kapi::cpu::exception const & context) -> bool
-      {
-        kstd::println(kstd::print_sink::stderr, "\tFault address: {:#018x}", context.access_address);
-        kstd::println(kstd::print_sink::stderr, "\tPresent: {}", context.is_present);
-        kstd::println(kstd::print_sink::stderr, "\tWrite: {}", context.is_write_access);
-        kstd::println(kstd::print_sink::stderr, "\tUser: {}", context.is_user_mode);
-
-        kapi::system::panic("Halting the system due to an unrecoverable page fault.");
-      }
-    } static constinit handler;
-  }  // namespace
-
-  auto init() -> void
-  {
-    kapi::cpu::set_exception_handler(handler);
-  }
-
-}  // namespace kernel::cpu
\ No newline at end of file
diff --git a/kernel/src/main.cpp b/kernel/src/main.cpp
index 6bd168c..45a4aae 100644
--- a/kernel/src/main.cpp
+++ b/kernel/src/main.cpp
@@ -4,7 +4,6 @@
 #include "kapi/memory.hpp"
 #include "kapi/system.hpp"
 
-#include "kernel/cpu.hpp"
 #include "kernel/devices/storage/storage_management.hpp"
 #include "kernel/filesystem/device_file.hpp"
 #include "kernel/filesystem/file_descriptor_table.hpp"
@@ -93,7 +92,6 @@ auto main() -> int
   kstd::println("[OS] IO subsystem initialized.");
 
   kapi::cpu::init();
-  kernel::cpu::init();
   kapi::cpu::enable_interrupts();
 
   kapi::memory::init();