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/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/IntrusiveList.h>
#include <Kernel/Devices/BlockDevice.h>
#include <Kernel/Interrupts/IRQHandler.h>
#include <Kernel/Locking/Mutex.h>
#include <Kernel/Storage/DiskPartition.h>
#include <Kernel/Storage/StorageController.h>
namespace Kernel {
class RamdiskDevice;
class StorageDevice : public BlockDevice {
friend class StorageManagement;
friend class DeviceManagement;
public:
// Note: this attribute describes the internal command set 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.
// The IDE controller code being aware of the possibility of ATAPI devices attached
// to the ATA bus, will check whether the Command set is ATA or SCSI and will act
// accordingly.
// Note: For now, there's simply no distinction between the interface type and the commandset.
// As mentioned above, ATAPI devices use the ATA interface with actual SCSI packets so
// the commandset is SCSI while the interface type is ATA. We simply don't support SCSI over ATA (ATAPI)
// and ATAPI is the exception to no-distinction rule. If we ever put SCSI support in the kernel,
// we can create another enum class to put the distinction.
enum class CommandSet {
PlainMemory,
SCSI,
ATA,
NVMe,
};
// Note: The most reliable way to address this device from userspace interfaces,
// such as SysFS, is to have one way to enumerate everything in the eyes of userspace.
// Therefore, SCSI LUN (logical unit number) addressing seem to be the most generic way to do this.
// For example, on a legacy ATA instance, one might connect an harddrive to the second IDE controller,
// to the Primary channel as a slave device, which translates to LUN 1:0:1.
// On NVMe, for example, connecting a second PCIe NVMe storage device as a sole NVMe namespace translates
// to LUN 1:0:0.
struct LUNAddress {
u32 controller_id;
u32 target_id;
u32 disk_id;
};
public:
virtual u64 max_addressable_block() const { return m_max_addressable_block; }
// ^BlockDevice
virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;
virtual bool can_read(OpenFileDescription const&, u64) const override;
virtual ErrorOr<size_t> write(OpenFileDescription&, u64, UserOrKernelBuffer const&, size_t) override;
virtual bool can_write(OpenFileDescription const&, u64) const override;
virtual void prepare_for_unplug() { m_partitions.clear(); }
Vector<NonnullLockRefPtr<DiskPartition>> const& partitions() const { return m_partitions; }
void add_partition(NonnullLockRefPtr<DiskPartition> disk_partition) { MUST(m_partitions.try_append(disk_partition)); }
LUNAddress const& logical_unit_number_address() const { return m_logical_unit_number_address; }
u32 parent_controller_hardware_relative_id() const { return m_hardware_relative_controller_id; }
virtual CommandSet command_set() const = 0;
StringView command_set_to_string_view() const;
// ^File
virtual ErrorOr<void> ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg) final;
protected:
StorageDevice(LUNAddress, u32 hardware_relative_controller_id, size_t sector_size, u64);
// Note: We want to be able to put distinction between Storage devices and Ramdisk-based devices.
// We do this because it will make selecting ramdisk devices much more easier in boot time in the kernel commandline.
StorageDevice(Badge<RamdiskDevice>, LUNAddress, u32 hardware_relative_controller_id, MajorNumber, MinorNumber, size_t sector_size, u64);
// ^DiskDevice
virtual StringView class_name() const override;
private:
virtual ErrorOr<void> after_inserting() override;
virtual void will_be_destroyed() override;
mutable IntrusiveListNode<StorageDevice, LockRefPtr<StorageDevice>> m_list_node;
Vector<NonnullLockRefPtr<DiskPartition>> m_partitions;
LUNAddress const m_logical_unit_number_address;
// Note: This data member should be used with LUNAddress target_id and disk_id.
// LUNs are agnostic system-wide addresses, so they are assigned without caring about the specific hardware interfaces.
// This class member on the other side, is meant to be assigned *per hardware type*,
// which means in contrast to the LUNAddress controller_id struct member, we take the index of the hardware
// controller among its fellow controllers of the same hardware type in the system.
u32 const m_hardware_relative_controller_id { 0 };
u64 m_max_addressable_block { 0 };
size_t m_blocks_per_page { 0 };
};
}
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