Kernel: Set IRQHandler m_shared_with_others when the irq is shared

If IRQHandler's IRQ is shared, then disable_irq() should not call the
controller to disable that IRQ as some other device might be using it.
IRQHandler had a private variable to indicate if it is being shared:
m_shared_with_others but it was never modified even if the IRQ was
shared.

Add a new member function set_shared_with_others() to enable/disable
m_shared_with_others member of IRQHandler class. This function is
called when an IRQHandler is being added/removed as a part of
SharedIRQHandler.

2 files changed, 4 insertions, 0 deletions

diff --git a/Kernel/Arch/x86_64/Interrupts.cpp b/Kernel/Arch/x86_64/Interrupts.cpp
index eedb7097c6..e316dfda43 100644
--- a/Kernel/Arch/x86_64/Interrupts.cpp
+++ b/Kernel/Arch/x86_64/Interrupts.cpp
@@ -11,6 +11,7 @@
 #include <Kernel/Arch/Interrupts.h>
 #include <Kernel/Arch/x86_64/Interrupts/PIC.h>
 #include <Kernel/Interrupts/GenericInterruptHandler.h>
+#include <Kernel/Interrupts/IRQHandler.h>
 #include <Kernel/Interrupts/SharedIRQHandler.h>
 #include <Kernel/Interrupts/SpuriousInterruptHandler.h>
 #include <Kernel/Interrupts/UnhandledInterruptHandler.h>
@@ -371,6 +372,7 @@ void register_generic_interrupt_handler(u8 interrupt_number, GenericInterruptHan
             return;
         }
         VERIFY(handler_slot->type() == HandlerType::IRQHandler);
+        static_cast<IRQHandler*>(handler_slot)->set_shared_with_others(true);
         auto& previous_handler = *handler_slot;
         handler_slot = nullptr;
         SharedIRQHandler::initialize(interrupt_number);
@@ -400,6 +402,7 @@ void unregister_generic_interrupt_handler(u8 interrupt_number, GenericInterruptH
     }
     if (!handler_slot->is_shared_handler()) {
         VERIFY(handler_slot->type() == HandlerType::IRQHandler);
+        static_cast<IRQHandler*>(handler_slot)->set_shared_with_others(false);
         handler_slot = nullptr;
         revert_to_unused_handler(interrupt_number);
         return;
diff --git a/Kernel/Interrupts/IRQHandler.h b/Kernel/Interrupts/IRQHandler.h
index c8b0eb2dd4..f21a524b42 100644
--- a/Kernel/Interrupts/IRQHandler.h
+++ b/Kernel/Interrupts/IRQHandler.h
@@ -32,6 +32,7 @@ public:
     virtual size_t sharing_devices_count() const override { return 0; }
     virtual bool is_shared_handler() const override { return false; }
     virtual bool is_sharing_with_others() const override { return m_shared_with_others; }
+    void set_shared_with_others(bool status) { m_shared_with_others = status; }
 
 protected:
     void change_irq_number(u8 irq);