jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#pragma once
8
9#include <AK/IntegralMath.h>
10#include <Kernel/Devices/Device.h>
11#include <Kernel/Library/LockWeakable.h>
12
13namespace Kernel {
14
15class AsyncBlockDeviceRequest;
16
17class BlockDevice : public Device {
18public:
19 virtual ~BlockDevice() override;
20
21 size_t block_size() const { return m_block_size; }
22 u8 block_size_log() const { return m_block_size_log; }
23 virtual bool is_seekable() const override { return true; }
24
25 bool read_block(u64 index, UserOrKernelBuffer&);
26 bool write_block(u64 index, UserOrKernelBuffer const&);
27
28 virtual void start_request(AsyncBlockDeviceRequest&) = 0;
29
30protected:
31 BlockDevice(MajorNumber major, MinorNumber minor, size_t block_size = PAGE_SIZE)
32 : Device(major, minor)
33 , m_block_size(block_size)
34 {
35 // 512 is the minimum sector size in most block devices
36 VERIFY(m_block_size >= 512);
37 VERIFY(is_power_of_two(m_block_size));
38 m_block_size_log = AK::log2(m_block_size);
39 }
40
41protected:
42 virtual bool is_block_device() const final { return true; }
43
44 virtual void after_inserting_add_symlink_to_device_identifier_directory() override final;
45 virtual void before_will_be_destroyed_remove_symlink_from_device_identifier_directory() override final;
46
47private:
48 // FIXME: These methods will be eventually removed after all nodes in /sys/dev/block/ are symlinks
49 virtual void after_inserting_add_to_device_identifier_directory() override final;
50 virtual void before_will_be_destroyed_remove_from_device_identifier_directory() override final;
51
52 size_t m_block_size { 0 };
53 u8 m_block_size_log { 0 };
54};
55
56class AsyncBlockDeviceRequest final : public AsyncDeviceRequest {
57public:
58 enum RequestType {
59 Read,
60 Write
61 };
62 AsyncBlockDeviceRequest(Device& block_device, RequestType request_type,
63 u64 block_index, u32 block_count, UserOrKernelBuffer const& buffer, size_t buffer_size);
64
65 RequestType request_type() const { return m_request_type; }
66 u64 block_index() const { return m_block_index; }
67 u32 block_count() const { return m_block_count; }
68 size_t block_size() const { return m_block_device.block_size(); }
69 UserOrKernelBuffer& buffer() { return m_buffer; }
70 UserOrKernelBuffer const& buffer() const { return m_buffer; }
71 size_t buffer_size() const { return m_buffer_size; }
72
73 virtual void start() override;
74 virtual StringView name() const override
75 {
76 switch (m_request_type) {
77 case Read:
78 return "BlockDeviceRequest (read)"sv;
79 case Write:
80 return "BlockDeviceRequest (write)"sv;
81 default:
82 VERIFY_NOT_REACHED();
83 }
84 }
85
86private:
87 BlockDevice& m_block_device;
88 const RequestType m_request_type;
89 const u64 m_block_index;
90 const u32 m_block_count;
91 UserOrKernelBuffer m_buffer;
92 const size_t m_buffer_size;
93};
94
95}