x86_64: only initialize BSP LAPIC

3 files changed, 29 insertions, 11 deletions

diff --git a/arch/x86_64/include/arch/devices/local_apic.hpp b/arch/x86_64/include/arch/devices/local_apic.hpp
index 7f125c3..7ae0a02 100644
--- a/arch/x86_64/include/arch/devices/local_apic.hpp
+++ b/arch/x86_64/include/arch/devices/local_apic.hpp
@@ -12,7 +12,8 @@ namespace arch::devices
 
   struct local_apic : kapi::devices::device
   {
-    local_apic(std::size_t major, std::size_t minor, std::uint64_t hardware_id, kapi::memory::physical_address base);
+    local_apic(std::size_t major, std::size_t minor, std::uint64_t hardware_id, kapi::memory::physical_address base,
+               bool is_bsp);
 
     auto init() -> bool override;
 
@@ -23,6 +24,7 @@ namespace arch::devices
     std::uint64_t m_hardware_id{};
     kapi::memory::physical_address m_base{};
     kapi::memory::linear_address m_virtual_base{};
+    bool m_is_bsp{};
   };
 
 }  // namespace arch::devices
diff --git a/arch/x86_64/kapi/platform.cpp b/arch/x86_64/kapi/platform.cpp
index c6e41d2..d881f8a 100644
--- a/arch/x86_64/kapi/platform.cpp
+++ b/arch/x86_64/kapi/platform.cpp
@@ -44,9 +44,9 @@ namespace kapi::platform
         {
           auto is_bsp = !bsp_found;
           bsp_found = true;
-          auto lapic = kstd::make_unique<arch::devices::local_apic>(interrupt_controller_major, core_index,
-                                                                    local_apic->apic_id(),
-                                                                    real_madt->local_interrupt_controller_address());
+          auto lapic = kstd::make_unique<arch::devices::local_apic>(
+              interrupt_controller_major, core_index, local_apic->apic_id(),
+              real_madt->local_interrupt_controller_address(), is_bsp);
           if (kapi::platform::cpu_detected(bus, core_major, core_index, local_apic->processor_id(), is_bsp,
                                            std::move(lapic)))
           {
diff --git a/arch/x86_64/src/devices/local_apic.cpp b/arch/x86_64/src/devices/local_apic.cpp
index 91e907a..e24e1d4 100644
--- a/arch/x86_64/src/devices/local_apic.cpp
+++ b/arch/x86_64/src/devices/local_apic.cpp
@@ -20,24 +20,40 @@ namespace arch::devices
   }  // namespace
 
   local_apic::local_apic(std::size_t major, std::size_t minor, std::uint64_t hardware_id,
-                         kapi::memory::physical_address base)
+                         kapi::memory::physical_address base, bool is_bsp)
       : kapi::devices::device{major, minor, "lapic"}
       , m_hardware_id{hardware_id}
       , m_base{base}
+      , m_is_bsp{is_bsp}
   {}
 
   auto local_apic::init() -> bool
   {
-    m_virtual_base = kapi::memory::allocate_mmio_region(1);
-    if (!kapi::memory::map_mmio_region(m_virtual_base, m_base, kapi::memory::page_mapper::flags::writable))
+    auto static shared_virtual_base = kapi::memory::allocate_mmio_region(1);
+    auto static is_mapped = false;
+
+    if (!is_mapped)
     {
-      kstd::println("[x86_64:DEV] LAPIC {} MMIO mapping failed!", m_hardware_id);
-      return false;
+      if (!kapi::memory::map_mmio_region(shared_virtual_base, m_base, kapi::memory::page_mapper::flags::writable))
+      {
+        kstd::println("[x86_64:DEV] LAPIC {} MMIO mapping failed!", m_hardware_id);
+        return false;
+      }
+      is_mapped = true;
     }
 
-    write_register(lapic_sivr_register, lapic_enable_bit | spurious_interrupt_vector);
+    m_virtual_base = shared_virtual_base;
+
+    if (m_is_bsp)
+    {
+      write_register(lapic_sivr_register, lapic_enable_bit | spurious_interrupt_vector);
 
-    kstd::println("[x86_64:DEV] LAPIC {} initialized. {:#018x}@{:#018x}", m_hardware_id, m_base, m_virtual_base);
+      kstd::println("[x86_64:DEV] LAPIC {} initialized. {:#018x}@{:#018x}", m_hardware_id, m_base, m_virtual_base);
+    }
+    else
+    {
+      kstd::println("[x86_64:DEV] LAPIC {} is not on the BSP, deferring intialization.", m_hardware_id);
+    }
 
     return true;
   }