Kernel/Memory: Introduce a method to allocate TypedMapping on the heap

This will be used later on to allocate such structure on the heap when
it is necessary to do so.

1 files changed, 13 insertions, 0 deletions

diff --git a/Kernel/Memory/TypedMapping.h b/Kernel/Memory/TypedMapping.h
index f1dd584aef..033d346473 100644
--- a/Kernel/Memory/TypedMapping.h
+++ b/Kernel/Memory/TypedMapping.h
@@ -6,7 +6,9 @@
 
 #pragma once
 
+#include <AK/NonnullOwnPtr.h>
 #include <AK/StringView.h>
+#include <AK/Try.h>
 #include <Kernel/Memory/MemoryManager.h>
 
 namespace Kernel::Memory {
@@ -25,6 +27,17 @@ struct TypedMapping {
 };
 
 template<typename T>
+static ErrorOr<NonnullOwnPtr<TypedMapping<T>>> adopt_new_nonnull_own_typed_mapping(PhysicalAddress paddr, size_t length, Region::Access access = Region::Access::Read)
+{
+    auto mapping_length = TRY(page_round_up(paddr.offset_in_page() + length));
+    auto region = TRY(MM.allocate_kernel_region(paddr.page_base(), mapping_length, {}, access));
+    auto table = TRY(adopt_nonnull_own_or_enomem(new (nothrow) Memory::TypedMapping<T>()));
+    table->region = move(region);
+    table->offset = paddr.offset_in_page();
+    return table;
+}
+
+template<typename T>
 static ErrorOr<TypedMapping<T>> map_typed(PhysicalAddress paddr, size_t length, Region::Access access = Region::Access::Read)
 {
     TypedMapping<T> table;