Kernel: Introduce IRQ sharing support

The support is very basic - Each component that needs to handle IRQs
inherits from InterruptHandler class. When the InterruptHandler
constructor is called it registers itself in a SharedInterruptHandler.
When an IRQ is fired, the SharedInterruptHandler is invoked, then it
iterates through a list of the registered InterruptHandlers.

Also, InterruptEnabler class was created to provide a way to enable IRQ
handling temporarily, similar to InterruptDisabler (in CPU.h, which does
the opposite).

In addition to that a PCI::Device class has been added, that inherits
from InterruptHandler.

3 files changed, 91 insertions, 0 deletions

diff --git a/Kernel/PCI/Definitions.h b/Kernel/PCI/Definitions.h
index d3dcf49d74..76344d77e2 100644
--- a/Kernel/PCI/Definitions.h
+++ b/Kernel/PCI/Definitions.h
@@ -178,5 +178,6 @@ class Access;
 class MMIOAccess;
 class IOAccess;
 class MMIOSegment;
+class Device;
 
 }
diff --git a/Kernel/PCI/Device.cpp b/Kernel/PCI/Device.cpp
new file mode 100644
index 0000000000..4a8e096b7a
--- /dev/null
+++ b/Kernel/PCI/Device.cpp
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <Kernel/PCI/Device.h>
+
+PCI::Device::Device(PCI::Address address)
+    : InterruptHandler(PCI::get_interrupt_line(address))
+    , m_pci_address(address)
+{
+    // FIXME: Register PCI device somewhere...
+}
+
+PCI::Device::Device(PCI::Address address, u8 interrupt_vector)
+    : InterruptHandler(interrupt_vector)
+    , m_pci_address(address)
+{
+    // FIXME: Register PCI device somewhere...
+}
+
+PCI::Device::~Device()
+{
+    // FIXME: Unregister the device
+}
diff --git a/Kernel/PCI/Device.h b/Kernel/PCI/Device.h
new file mode 100644
index 0000000000..edcc435407
--- /dev/null
+++ b/Kernel/PCI/Device.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+#include <Kernel/InterruptHandler.h>
+#include <Kernel/PCI/Definitions.h>
+
+class PCI::Device : public InterruptHandler {
+public:
+    Address get_pci_address() const { return m_pci_address; };
+
+protected:
+    Device(Address pci_address);
+    Device(Address pci_address, u8 interrupt_vector);
+    ~Device();
+
+private:
+    Address m_pci_address;
+};