From 7db6b77e7545f4224a4ebd2f0a97b753d291b4de Mon Sep 17 00:00:00 2001
From: Liav A <liavalb@gmail.com>
Date: Fri, 22 Apr 2022 16:15:41 +0300
Subject: [PATCH] Kernel: Export both interface type and command set of a
 StorageDevice

---
 Kernel/Storage/ATA/ATADiskDevice.h   |  1 +
 Kernel/Storage/ATA/ATAPIDiscDevice.h |  1 +
 Kernel/Storage/NVMe/NVMeNameSpace.h  |  1 +
 Kernel/Storage/Ramdisk/Device.h      |  1 +
 Kernel/Storage/StorageDevice.cpp     | 34 ++++++++++++++++++++++++++++
 Kernel/Storage/StorageDevice.h       | 16 +++++++++++++
 6 files changed, 54 insertions(+)

diff --git a/Kernel/Storage/ATA/ATADiskDevice.h b/Kernel/Storage/ATA/ATADiskDevice.h
index 4f08973ca82..5d611e01206 100644
--- a/Kernel/Storage/ATA/ATADiskDevice.h
+++ b/Kernel/Storage/ATA/ATADiskDevice.h
@@ -26,6 +26,7 @@ public:
     virtual CommandSet command_set() const override { return CommandSet::ATA; }
 
 private:
+    virtual InterfaceType interface_type() const override { return InterfaceType::ATA; }
     ATADiskDevice(ATAController const&, Address, MinorNumber, u16, u16, u64, NonnullOwnPtr<KString>);
 
     // ^DiskDevice
diff --git a/Kernel/Storage/ATA/ATAPIDiscDevice.h b/Kernel/Storage/ATA/ATAPIDiscDevice.h
index bfb80befe92..daed2e9c7e5 100644
--- a/Kernel/Storage/ATA/ATAPIDiscDevice.h
+++ b/Kernel/Storage/ATA/ATAPIDiscDevice.h
@@ -26,6 +26,7 @@ public:
     virtual CommandSet command_set() const override { return CommandSet::SCSI; }
 
 private:
+    virtual InterfaceType interface_type() const override { return InterfaceType::ATA; }
     ATAPIDiscDevice(ATAController const&, Address, MinorNumber, u16, u64, NonnullOwnPtr<KString>);
 
     // ^DiskDevice
diff --git a/Kernel/Storage/NVMe/NVMeNameSpace.h b/Kernel/Storage/NVMe/NVMeNameSpace.h
index b36cf2aa61f..1890d714600 100644
--- a/Kernel/Storage/NVMe/NVMeNameSpace.h
+++ b/Kernel/Storage/NVMe/NVMeNameSpace.h
@@ -29,6 +29,7 @@ public:
     void start_request(AsyncBlockDeviceRequest& request) override;
 
 private:
+    virtual InterfaceType interface_type() const override { return InterfaceType::NVMe; }
     u16 m_nsid;
     NonnullRefPtrVector<NVMeQueue> m_queues;
 };
diff --git a/Kernel/Storage/Ramdisk/Device.h b/Kernel/Storage/Ramdisk/Device.h
index 0e4ef6cca9b..dc398281a88 100644
--- a/Kernel/Storage/Ramdisk/Device.h
+++ b/Kernel/Storage/Ramdisk/Device.h
@@ -32,6 +32,7 @@ private:
 
     // ^StorageDevice
     virtual CommandSet command_set() const override { return CommandSet::PlainMemory; }
+    virtual InterfaceType interface_type() const override { return InterfaceType::PlainMemory; }
 
     Mutex m_lock { "RamdiskDevice"sv };
 
diff --git a/Kernel/Storage/StorageDevice.cpp b/Kernel/Storage/StorageDevice.cpp
index 339b61cb313..6c8cc784cbb 100644
--- a/Kernel/Storage/StorageDevice.cpp
+++ b/Kernel/Storage/StorageDevice.cpp
@@ -27,6 +27,40 @@ StringView StorageDevice::class_name() const
     return "StorageDevice"sv;
 }
 
+StringView StorageDevice::command_set_to_string_view() const
+{
+    switch (command_set()) {
+    case CommandSet::PlainMemory:
+        return "memory"sv;
+    case CommandSet::SCSI:
+        return "scsi"sv;
+    case CommandSet::ATA:
+        return "ata"sv;
+    case CommandSet::NVMe:
+        return "nvme"sv;
+    default:
+        break;
+    }
+    VERIFY_NOT_REACHED();
+}
+
+StringView StorageDevice::interface_type_to_string_view() const
+{
+    switch (interface_type()) {
+    case InterfaceType::PlainMemory:
+        return "memory"sv;
+    case InterfaceType::SCSI:
+        return "scsi"sv;
+    case InterfaceType::ATA:
+        return "ata"sv;
+    case InterfaceType::NVMe:
+        return "nvme"sv;
+    default:
+        break;
+    }
+    VERIFY_NOT_REACHED();
+}
+
 ErrorOr<size_t> StorageDevice::read(OpenFileDescription&, u64 offset, UserOrKernelBuffer& outbuf, size_t len)
 {
     u64 index = offset >> block_size_log();
diff --git a/Kernel/Storage/StorageDevice.h b/Kernel/Storage/StorageDevice.h
index 2b178bc7441..a7747b1a119 100644
--- a/Kernel/Storage/StorageDevice.h
+++ b/Kernel/Storage/StorageDevice.h
@@ -33,6 +33,18 @@ public:
         NVMe,
     };
 
+    // Note: this attribute describes the interface type of a Storage device.
+    // For example, an ordinary harddrive utilizes the ATA command set, while
+    // an ATAPI device (e.g. Optical drive) that is connected to the ATA bus,
+    // is actually using SCSI commands (packets) encapsulated inside an ATA command.
+    // Therefore, an ATAPI device is still using the ATA interface.
+    enum class InterfaceType {
+        PlainMemory,
+        SCSI,
+        ATA,
+        NVMe,
+    };
+
 public:
     virtual u64 max_addressable_block() const { return m_max_addressable_block; }
 
@@ -52,6 +64,9 @@ public:
 
     virtual CommandSet command_set() const = 0;
 
+    StringView interface_type_to_string_view() const;
+    StringView command_set_to_string_view() const;
+
     // ^File
     virtual ErrorOr<void> ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg) final;
 
@@ -61,6 +76,7 @@ protected:
     virtual StringView class_name() const override;
 
 private:
+    virtual InterfaceType interface_type() const = 0;
     mutable IntrusiveListNode<StorageDevice, RefPtr<StorageDevice>> m_list_node;
     NonnullRefPtrVector<DiskPartition> m_partitions;