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ladybird/Kernel/VM/TypedMapping.h

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Kernel: Add typed_map<T>(PhysicalAddress) and use it in ACPI parsing There was a frequently occurring pattern of "map this physical address into kernel VM, then read from it, then unmap it again". This new typed_map() encapsulates that logic by giving you back a typed pointer to the kind of structure you're interested in accessing. It returns a TypedMapping<T> that can be used mostly like a pointer. When destroyed, the TypedMapping object will unmap the memory. :^)
2020-04-09 17:12:58 +02:00
/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
*
Everything: Move to SPDX license identifiers in all files. SPDX License Identifiers are a more compact / standardized way of representing file license information. See: https://spdx.dev/resources/use/#identifiers This was done with the `ambr` search and replace tool. ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
2021-04-22 01:24:48 -07:00
* SPDX-License-Identifier: BSD-2-Clause
Kernel: Add typed_map<T>(PhysicalAddress) and use it in ACPI parsing There was a frequently occurring pattern of "map this physical address into kernel VM, then read from it, then unmap it again". This new typed_map() encapsulates that logic by giving you back a typed pointer to the kind of structure you're interested in accessing. It returns a TypedMapping<T> that can be used mostly like a pointer. When destroyed, the TypedMapping object will unmap the memory. :^)
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*/
#pragma once
#include <AK/StringView.h>
#include <Kernel/VM/MemoryManager.h>
namespace Kernel {
template<typename T>
struct TypedMapping {
const T* ptr() const { return reinterpret_cast<const T*>(region->vaddr().offset(offset).as_ptr()); }
T* ptr() { return reinterpret_cast<T*>(region->vaddr().offset(offset).as_ptr()); }
const T* operator->() const { return ptr(); }
Kernel: Add non-const version of TypedMapping::operator->()
2020-05-23 15:57:19 +02:00
T* operator->() { return ptr(); }
Kernel: Add typed_map<T>(PhysicalAddress) and use it in ACPI parsing There was a frequently occurring pattern of "map this physical address into kernel VM, then read from it, then unmap it again". This new typed_map() encapsulates that logic by giving you back a typed pointer to the kind of structure you're interested in accessing. It returns a TypedMapping<T> that can be used mostly like a pointer. When destroyed, the TypedMapping object will unmap the memory. :^)
2020-04-09 17:12:58 +02:00
const T& operator*() const { return *ptr(); }
T& operator*() { return *ptr(); }
OwnPtr<Region> region;
size_t offset { 0 };
};
template<typename T>
Kernel: Make MemoryManager API type-safe for Region::Access enum Increase type-safety moving the MemoryManager APIs which take a Region::Access to actually use that type instead of a `u8`. Eventually the actually m_access can be moved there as well, but I hit some weird bug where it wasn't using the correct operators in `set_access_bit(..)` even though it's declared (and tested). Something to fix-up later.
2021-03-06 19:33:25 -08:00
static TypedMapping<T> map_typed(PhysicalAddress paddr, size_t length, Region::Access access = Region::Access::Read)
Kernel: Add typed_map<T>(PhysicalAddress) and use it in ACPI parsing There was a frequently occurring pattern of "map this physical address into kernel VM, then read from it, then unmap it again". This new typed_map() encapsulates that logic by giving you back a typed pointer to the kind of structure you're interested in accessing. It returns a TypedMapping<T> that can be used mostly like a pointer. When destroyed, the TypedMapping object will unmap the memory. :^)
2020-04-09 17:12:58 +02:00
{
TypedMapping<T> table;
Kernel: Assert if rounding-up-to-page-size would wrap around to 0 If we try to align a number above 0xfffff000 to the next multiple of the page size (4 KiB), it would wrap around to 0. This is most likely never what we want, so let's assert if that happens.
2021-02-14 09:57:19 +01:00
table.region = MM.allocate_kernel_region(paddr.page_base(), page_round_up(length), {}, access);
Kernel: Add typed_map<T>(PhysicalAddress) and use it in ACPI parsing There was a frequently occurring pattern of "map this physical address into kernel VM, then read from it, then unmap it again". This new typed_map() encapsulates that logic by giving you back a typed pointer to the kind of structure you're interested in accessing. It returns a TypedMapping<T> that can be used mostly like a pointer. When destroyed, the TypedMapping object will unmap the memory. :^)
2020-04-09 17:12:58 +02:00
table.offset = paddr.offset_in_page();
return table;
}
template<typename T>
static TypedMapping<T> map_typed(PhysicalAddress paddr)
{
return map_typed<T>(paddr, sizeof(T));
}
template<typename T>
static TypedMapping<T> map_typed_writable(PhysicalAddress paddr)
{
return map_typed<T>(paddr, sizeof(T), Region::Access::Read | Region::Access::Write);
}
}
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