1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
// KBuffer: Statically sized kernel-only memory buffer.
//
// A KBuffer is a value-type convenience class that wraps a NonnullRefPtr<KBufferImpl>.
// The memory is allocated via the global kernel-only page allocator, rather than via
// kmalloc() which is what ByteBuffer/Vector/etc will use.
//
// This makes KBuffer a little heavier to allocate, but much better for large and/or
// long-lived allocations, since they don't put all that weight and pressure on the
// severely limited kmalloc heap.
#include <AK/Assertions.h>
#include <AK/ByteBuffer.h>
#include <AK/LogStream.h>
#include <AK/Memory.h>
#include <AK/StringView.h>
#include <Kernel/VM/MemoryManager.h>
#include <Kernel/VM/Region.h>
namespace Kernel {
class KBufferImpl : public RefCounted<KBufferImpl> {
public:
static RefPtr<KBufferImpl> try_create_with_size(size_t size, u8 access, const char* name = "KBuffer", AllocationStrategy strategy = AllocationStrategy::Reserve)
{
auto region = MM.allocate_kernel_region(PAGE_ROUND_UP(size), name, access, false, strategy);
if (!region)
return nullptr;
return adopt(*new KBufferImpl(region.release_nonnull(), size, strategy));
}
static RefPtr<KBufferImpl> try_create_with_bytes(ReadonlyBytes bytes, u8 access, const char* name = "KBuffer", AllocationStrategy strategy = AllocationStrategy::Reserve)
{
auto region = MM.allocate_kernel_region(PAGE_ROUND_UP(bytes.size()), name, access, false, strategy);
if (!region)
return nullptr;
memcpy(region->vaddr().as_ptr(), bytes.data(), bytes.size());
return adopt(*new KBufferImpl(region.release_nonnull(), bytes.size(), strategy));
}
static RefPtr<KBufferImpl> create_with_size(size_t size, u8 access, const char* name, AllocationStrategy strategy = AllocationStrategy::Reserve)
{
return try_create_with_size(size, access, name, strategy);
}
static RefPtr<KBufferImpl> copy(const void* data, size_t size, u8 access, const char* name)
{
auto buffer = create_with_size(size, access, name, AllocationStrategy::AllocateNow);
if (!buffer)
return {};
memcpy(buffer->data(), data, size);
return buffer;
}
bool expand(size_t new_capacity)
{
auto new_region = MM.allocate_kernel_region(PAGE_ROUND_UP(new_capacity), m_region->name(), m_region->access(), false, m_allocation_strategy);
if (!new_region)
return false;
if (m_region && m_size > 0)
memcpy(new_region->vaddr().as_ptr(), data(), min(m_region->size(), m_size));
m_region = new_region.release_nonnull();
return true;
}
u8* data() { return m_region->vaddr().as_ptr(); }
const u8* data() const { return m_region->vaddr().as_ptr(); }
size_t size() const { return m_size; }
size_t capacity() const { return m_region->size(); }
void set_size(size_t size)
{
ASSERT(size <= capacity());
m_size = size;
}
const Region& region() const { return *m_region; }
Region& region() { return *m_region; }
private:
explicit KBufferImpl(NonnullOwnPtr<Region>&& region, size_t size, AllocationStrategy strategy)
: m_size(size)
, m_allocation_strategy(strategy)
, m_region(move(region))
{
}
size_t m_size { 0 };
AllocationStrategy m_allocation_strategy { AllocationStrategy::Reserve };
NonnullOwnPtr<Region> m_region;
};
class KBuffer {
public:
explicit KBuffer(RefPtr<KBufferImpl>&& impl)
: m_impl(move(impl))
{
}
static OwnPtr<KBuffer> try_create_with_size(size_t size, u8 access = Region::Access::Read | Region::Access::Write, const char* name = "KBuffer", AllocationStrategy strategy = AllocationStrategy::Reserve)
{
auto impl = KBufferImpl::try_create_with_size(size, access, name, strategy);
if (!impl)
return nullptr;
return adopt_own(*new KBuffer(impl.release_nonnull()));
}
static OwnPtr<KBuffer> try_create_with_bytes(ReadonlyBytes bytes, u8 access = Region::Access::Read | Region::Access::Write, const char* name = "KBuffer", AllocationStrategy strategy = AllocationStrategy::Reserve)
{
auto impl = KBufferImpl::try_create_with_bytes(bytes, access, name, strategy);
if (!impl)
return nullptr;
return adopt_own(*new KBuffer(impl.release_nonnull()));
}
static KBuffer create_with_size(size_t size, u8 access = Region::Access::Read | Region::Access::Write, const char* name = "KBuffer", AllocationStrategy strategy = AllocationStrategy::Reserve)
{
return KBuffer(KBufferImpl::create_with_size(size, access, name, strategy));
}
static KBuffer copy(const void* data, size_t size, u8 access = Region::Access::Read | Region::Access::Write, const char* name = "KBuffer")
{
return KBuffer(KBufferImpl::copy(data, size, access, name));
}
bool is_null() const { return !m_impl; }
u8* data() { return m_impl ? m_impl->data() : nullptr; }
const u8* data() const { return m_impl ? m_impl->data() : nullptr; }
size_t size() const { return m_impl ? m_impl->size() : 0; }
size_t capacity() const { return m_impl ? m_impl->capacity() : 0; }
void* end_pointer() { return data() + size(); }
const void* end_pointer() const { return data() + size(); }
void set_size(size_t size) { m_impl->set_size(size); }
const KBufferImpl& impl() const { return *m_impl; }
RefPtr<KBufferImpl> take_impl() { return move(m_impl); }
KBuffer(const ByteBuffer& buffer, u8 access = Region::Access::Read | Region::Access::Write, const char* name = "KBuffer")
: m_impl(KBufferImpl::copy(buffer.data(), buffer.size(), access, name))
{
}
private:
RefPtr<KBufferImpl> m_impl;
};
inline const LogStream& operator<<(const LogStream& stream, const KBuffer& value)
{
return stream << StringView(value.data(), value.size());
}
}
|
