ladybird/Kernel/Storage/StorageDevice.h
Pankaj Raghav 3b27e28e67 Kernel: Cache blocks_per_page in StorageDevice class
Instead of calculating blocks_per_page in every IO, cache it to save
CPU cycles as that value will not change after initialization.
2022-01-29 17:41:06 +02:00

74 lines
2.6 KiB
C++

/*
* 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/Partition/DiskPartition.h>
#include <Kernel/Storage/StorageController.h>
namespace Kernel {
class StorageDevice : public BlockDevice {
friend class StorageManagement;
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.
enum class CommandSet {
PlainMemory,
SCSI,
ATA,
NVMe,
};
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(const OpenFileDescription&, u64) const override;
virtual ErrorOr<size_t> write(OpenFileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
virtual bool can_write(const OpenFileDescription&, u64) const override;
virtual void prepare_for_unplug() { m_partitions.clear(); }
// FIXME: Remove this method after figuring out another scheme for naming.
StringView early_storage_name() const;
NonnullRefPtrVector<DiskPartition> const& partitions() const { return m_partitions; }
void add_partition(NonnullRefPtr<DiskPartition> disk_partition) { MUST(m_partitions.try_append(disk_partition)); }
virtual CommandSet command_set() const = 0;
// ^File
virtual ErrorOr<void> ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg) final;
protected:
StorageDevice(MajorNumber, MinorNumber, size_t, u64, NonnullOwnPtr<KString>);
// ^DiskDevice
virtual StringView class_name() const override;
private:
mutable IntrusiveListNode<StorageDevice, RefPtr<StorageDevice>> m_list_node;
NonnullRefPtrVector<DiskPartition> m_partitions;
// FIXME: Remove this method after figuring out another scheme for naming.
NonnullOwnPtr<KString> m_early_storage_device_name;
u64 m_max_addressable_block { 0 };
size_t m_blocks_per_page { 0 };
};
}