serenity/Kernel/Memory/ScatterGatherList.cpp
Andreas Kling 75564b4a5f Kernel: Make kernel region allocators return KResultOr<NOP<Region>>
This expands the reach of error propagation greatly throughout the
kernel. Sadly, it also exposes the fact that we're allocating (and
doing other fallible things) in constructors all over the place.

This patch doesn't attempt to address that of course. That's work for
our future selves.
2021-09-06 01:55:27 +02:00

30 lines
1.2 KiB
C++

/*
* Copyright (c) 2021, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Memory/ScatterGatherList.h>
namespace Kernel::Memory {
RefPtr<ScatterGatherList> ScatterGatherList::try_create(AsyncBlockDeviceRequest& request, Span<NonnullRefPtr<PhysicalPage>> allocated_pages, size_t device_block_size)
{
auto maybe_vm_object = AnonymousVMObject::try_create_with_physical_pages(allocated_pages);
if (maybe_vm_object.is_error()) {
// FIXME: Would be nice to be able to return a KResultOr here.
return {};
}
return adopt_ref_if_nonnull(new (nothrow) ScatterGatherList(maybe_vm_object.release_value(), request, device_block_size));
}
ScatterGatherList::ScatterGatherList(NonnullRefPtr<AnonymousVMObject> vm_object, AsyncBlockDeviceRequest& request, size_t device_block_size)
: m_vm_object(move(vm_object))
{
auto region_or_error = MM.allocate_kernel_region_with_vmobject(m_vm_object, page_round_up((request.block_count() * device_block_size)), "AHCI Scattered DMA", Region::Access::Read | Region::Access::Write, Region::Cacheable::Yes);
if (region_or_error.is_error())
TODO();
m_dma_region = region_or_error.release_value();
}
}