Kernel/PCI: Add basic support for the VMD PCI bridge device

Author: https://github.com/supercomputer7
Commit: eb9c8f3895
Pull-request: https://github.com/SerenityOS/serenity/pull/12063
Reviewed-by: https://github.com/tomuta ✅

Kernel/Bus/PCI/Controller/VolumeManagementDevice.cpp

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/ByteReader.h>
+#include <Kernel/Arch/x86/IO.h>
+#include <Kernel/Bus/PCI/API.h>
+#include <Kernel/Bus/PCI/Access.h>
+#include <Kernel/Bus/PCI/Controller/VolumeManagementDevice.h>
+
+namespace Kernel::PCI {
+
+static Atomic<u32> s_vmd_pci_domain_number = 0x10000;
+
+NonnullOwnPtr<VolumeManagementDevice> VolumeManagementDevice::must_create(PCI::DeviceIdentifier const& device_identifier)
+{
+    u8 start_bus = 0;
+    switch ((PCI::read16(device_identifier.address(), static_cast<PCI::RegisterOffset>(0x44)) >> 8) & 0x3) {
+    case 0:
+        break;
+    case 1:
+        start_bus = 128;
+        break;
+    case 2:
+        start_bus = 224;
+        break;
+    default:
+        dbgln("VMD @ {}: Unknown bus offset option was set to {}", device_identifier.address(),
+            ((PCI::read16(device_identifier.address(), static_cast<PCI::RegisterOffset>(0x44)) >> 8) & 0x3));
+        VERIFY_NOT_REACHED();
+    }
+
+    // FIXME: The end bus might not be 255, so we actually need to check it with the
+    // resource size of BAR0.
+    dbgln("VMD Host bridge @ {}: Start bus at {}, end bus {}", device_identifier.address(), start_bus, 0xff);
+    PCI::Domain domain { s_vmd_pci_domain_number++, start_bus, 0xff };
+    auto start_address = PhysicalAddress(PCI::get_BAR0(device_identifier.address())).page_base();
+    return adopt_own_if_nonnull(new (nothrow) VolumeManagementDevice(domain, start_address)).release_nonnull();
+}
+
+void VolumeManagementDevice::write8_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field, u8 value)
+{
+    SpinlockLocker locker(m_config_lock);
+    // Note: We must write then read to ensure completion before returning.
+    MemoryBackedHostBridge::write8_field(bus, device, function, field, value);
+    MemoryBackedHostBridge::read8_field(bus, device, function, field);
+}
+void VolumeManagementDevice::write16_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field, u16 value)
+{
+    SpinlockLocker locker(m_config_lock);
+    // Note: We must write then read to ensure completion before returning.
+    MemoryBackedHostBridge::write16_field(bus, device, function, field, value);
+    MemoryBackedHostBridge::read16_field(bus, device, function, field);
+}
+void VolumeManagementDevice::write32_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field, u32 value)
+{
+    SpinlockLocker locker(m_config_lock);
+    // Note: We must write then read to ensure completion before returning.
+    MemoryBackedHostBridge::write32_field(bus, device, function, field, value);
+    MemoryBackedHostBridge::read32_field(bus, device, function, field);
+}
+
+u8 VolumeManagementDevice::read8_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field)
+{
+    SpinlockLocker locker(m_config_lock);
+    return MemoryBackedHostBridge::read8_field(bus, device, function, field);
+}
+u16 VolumeManagementDevice::read16_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field)
+{
+    SpinlockLocker locker(m_config_lock);
+    return MemoryBackedHostBridge::read16_field(bus, device, function, field);
+}
+u32 VolumeManagementDevice::read32_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field)
+{
+    SpinlockLocker locker(m_config_lock);
+    return MemoryBackedHostBridge::read32_field(bus, device, function, field);
+}
+
+VolumeManagementDevice::VolumeManagementDevice(PCI::Domain const& domain, PhysicalAddress start_address)
+    : MemoryBackedHostBridge(domain, start_address)
+{
+}
+
+}