1 files changed, 95 insertions, 0 deletions
diff --git a/Kernel/FileSystem/SysFS/Subsystems/Bus/PCI/DeviceAttribute.cpp b/Kernel/FileSystem/SysFS/Subsystems/Bus/PCI/DeviceAttribute.cpp
new file mode 100644
index 0000000000..652dfb5064
--- /dev/null
+++ b/Kernel/FileSystem/SysFS/Subsystems/Bus/PCI/DeviceAttribute.cpp
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Bus/PCI/API.h>
+#include <Kernel/Bus/PCI/Access.h>
+#include <Kernel/Debug.h>
+#include <Kernel/FileSystem/SysFS/Subsystems/Bus/PCI/DeviceAttribute.h>
+#include <Kernel/Sections.h>
+
+namespace Kernel {
+
+StringView PCIDeviceAttributeSysFSComponent::name() const
+{
+    switch (m_offset) {
+    case PCI::RegisterOffset::VENDOR_ID:
+        return "vendor"sv;
+    case PCI::RegisterOffset::DEVICE_ID:
+        return "device_id"sv;
+    case PCI::RegisterOffset::CLASS:
+        return "class"sv;
+    case PCI::RegisterOffset::SUBCLASS:
+        return "subclass"sv;
+    case PCI::RegisterOffset::REVISION_ID:
+        return "revision"sv;
+    case PCI::RegisterOffset::PROG_IF:
+        return "progif"sv;
+    case PCI::RegisterOffset::SUBSYSTEM_VENDOR_ID:
+        return "subsystem_vendor"sv;
+    case PCI::RegisterOffset::SUBSYSTEM_ID:
+        return "subsystem_id"sv;
+    case PCI::RegisterOffset::BAR0:
+        return "bar0"sv;
+    case PCI::RegisterOffset::BAR1:
+        return "bar1"sv;
+    case PCI::RegisterOffset::BAR2:
+        return "bar2"sv;
+    case PCI::RegisterOffset::BAR3:
+        return "bar3"sv;
+    case PCI::RegisterOffset::BAR4:
+        return "bar4"sv;
+    case PCI::RegisterOffset::BAR5:
+        return "bar5"sv;
+    default:
+        VERIFY_NOT_REACHED();
+    }
+}
+
+NonnullRefPtr<PCIDeviceAttributeSysFSComponent> PCIDeviceAttributeSysFSComponent::create(PCIDeviceSysFSDirectory const& device, PCI::RegisterOffset offset, size_t field_bytes_width)
+{
+    return adopt_ref(*new (nothrow) PCIDeviceAttributeSysFSComponent(device, offset, field_bytes_width));
+}
+
+PCIDeviceAttributeSysFSComponent::PCIDeviceAttributeSysFSComponent(PCIDeviceSysFSDirectory const& device, PCI::RegisterOffset offset, size_t field_bytes_width)
+    : SysFSComponent()
+    , m_device(device)
+    , m_offset(offset)
+    , m_field_bytes_width(field_bytes_width)
+{
+}
+
+ErrorOr<size_t> PCIDeviceAttributeSysFSComponent::read_bytes(off_t offset, size_t count, UserOrKernelBuffer& buffer, OpenFileDescription*) const
+{
+    auto blob = TRY(try_to_generate_buffer());
+
+    if ((size_t)offset >= blob->size())
+        return 0;
+
+    ssize_t nread = min(static_cast<off_t>(blob->size() - offset), static_cast<off_t>(count));
+    TRY(buffer.write(blob->data() + offset, nread));
+    return nread;
+}
+
+ErrorOr<NonnullOwnPtr<KBuffer>> PCIDeviceAttributeSysFSComponent::try_to_generate_buffer() const
+{
+    OwnPtr<KString> value;
+    switch (m_field_bytes_width) {
+    case 1:
+        value = TRY(KString::formatted("{:#x}", PCI::read8(m_device->address(), m_offset)));
+        break;
+    case 2:
+        value = TRY(KString::formatted("{:#x}", PCI::read16(m_device->address(), m_offset)));
+        break;
+    case 4:
+        value = TRY(KString::formatted("{:#x}", PCI::read32(m_device->address(), m_offset)));
+        break;
+    default:
+        VERIFY_NOT_REACHED();
+    }
+
+    return KBuffer::try_create_with_bytes(value->view().bytes());
+}
+}